Datasets:

anakin87

/

medrag-pubmed-chunk

like 0

PMID:30756

Presence of Escherichia coli of a deaminase and a reductase involved in biosynthesis of riboflavin.

Two enzymes have been partially purified from extracts of Escherchia coli B which together catalyze the conversion of the product of the action of GTP cyclohydrolase II, 2,5-diamino-6-oxy-4-(5'-phosphoribosylamine)pyrimidine, to 5-amino-2,6-dioxy-4-(5'-phosphoribitylamine)pyrimidine. These two compounds are currently thought to be intermediates in the biosynthesis of riboflavin. The enzymatic conversion occurs in two steps. The product of the action of GTP cyclohydrolase II first undergoes hydrolytic deamination at carbon 2 of the ring, followed by reduction of the ribosylamino group to a ribitylamino group. The enzyme which catalyzes the first step, herein called the "deaminase," has been purified 200-fold. The activity was assayed by detecting the conversion of the product of the reaction catalyzed by GTP cyclohydrolase II to a compound which reacts with butanedione to form 6,7-dimethyllumazine. The enzyme has a molecular weight of approximately 80,000 and a pH optimum of 9.1. The dephosphorylated form of the substrate is not deaminated in the presence of the enzyme. The assay for the enzyme which catalyzes the second step, referred to here as the "reductase," involves the detection of the conversion of the product of the deaminase-catalyzed reaction to a compound which, after treatment with alkaline phosphatase, reacts with butanedione to form 6,7-dimethyl-8-ribityllumazine. The reductase has a molecular weight of approximately 40,000 and a pH optimum of 7.5. Like the deaminase, the reductase does not act on the dephosphorylated form of its substrate. Reduced nicotinamide adenine dinucleotide phosphate is required as a cofactor; reduced nicotinamide adenine dinucleotide can be used about 30% as well as the phosphate form. The activity of neither enzyme is inhibited by riboflavin, FMN, or flavine adenine dinucleotide.

Presence of Escherichia coli of a deaminase and a reductase involved in biosynthesis of riboflavin. Two enzymes have been partially purified from extracts of Escherchia coli B which together catalyze the conversion of the product of the action of GTP cyclohydrolase II, 2,5-diamino-6-oxy-4-(5'-phosphoribosylamine)pyrimidine, to 5-amino-2,6-dioxy-4-(5'-phosphoribitylamine)pyrimidine. These two compounds are currently thought to be intermediates in the biosynthesis of riboflavin. The enzymatic conversion occurs in two steps. The product of the action of GTP cyclohydrolase II first undergoes hydrolytic deamination at carbon 2 of the ring, followed by reduction of the ribosylamino group to a ribitylamino group. The enzyme which catalyzes the first step, herein called the "deaminase," has been purified 200-fold. The activity was assayed by detecting the conversion of the product of the reaction catalyzed by GTP cyclohydrolase II to a compound which reacts with butanedione to form 6,7-dimethyllumazine. The enzyme has a molecular weight of approximately 80,000 and a pH optimum of 9.1. The dephosphorylated form of the substrate is not deaminated in the presence of the enzyme. The assay for the enzyme which catalyzes the second step, referred to here as the "reductase," involves the detection of the conversion of the product of the deaminase-catalyzed reaction to a compound which, after treatment with alkaline phosphatase, reacts with butanedione to form 6,7-dimethyl-8-ribityllumazine. The reductase has a molecular weight of approximately 40,000 and a pH optimum of 7.5. Like the deaminase, the reductase does not act on the dephosphorylated form of its substrate. Reduced nicotinamide adenine dinucleotide phosphate is required as a cofactor; reduced nicotinamide adenine dinucleotide can be used about 30% as well as the phosphate form. The activity of neither enzyme is inhibited by riboflavin, FMN, or flavine adenine dinucleotide.

PMID:30757

Regulation of uridylic acid biosynthesis in the cyanobacterium Anabaena variabilis.

The pathway of uridylic acid biosynthesis established by Leiberman, Kornberg, and Simms has been shown to be operative in the filamentous cyanobacterium Anabaena variabilis. The only enzyme of uridylic acid biosynthesis found to be lacking in two uracil-requiring strains of A. variabilis was aspartate transcarbamylase, the first enzyme in the pathway of de novo biosynthesis of uridvlic acid. Neither uracil-limited growth of a uracil-requiring mutant nor growth of the wild type in high concentrations of uracil resulted in substantial changes in the specific activities of enzymes of uridylic acid biosynthesis. It is therefore concluded that A. variabilis does not regulate all enzymes of this pathway by means of repression. However, control of the flow of intermediates through this pathway is possible by feedback inhibition of aspartate transcarbamylase by a variety of nucleotides.

Regulation of uridylic acid biosynthesis in the cyanobacterium Anabaena variabilis. The pathway of uridylic acid biosynthesis established by Leiberman, Kornberg, and Simms has been shown to be operative in the filamentous cyanobacterium Anabaena variabilis. The only enzyme of uridylic acid biosynthesis found to be lacking in two uracil-requiring strains of A. variabilis was aspartate transcarbamylase, the first enzyme in the pathway of de novo biosynthesis of uridvlic acid. Neither uracil-limited growth of a uracil-requiring mutant nor growth of the wild type in high concentrations of uracil resulted in substantial changes in the specific activities of enzymes of uridylic acid biosynthesis. It is therefore concluded that A. variabilis does not regulate all enzymes of this pathway by means of repression. However, control of the flow of intermediates through this pathway is possible by feedback inhibition of aspartate transcarbamylase by a variety of nucleotides.

PMID:30758

Hydrolysis of phosphatidylethanolamine and phosphatidylglycerol by outer membrane phospholipase A from Acinetobacter sp. HO1-N.

An outer membrane phospholipase A active against phosphatidylglycerol and phosphatidylethanolamine was characterized from Acinetobacter sp. HO1-N.

Hydrolysis of phosphatidylethanolamine and phosphatidylglycerol by outer membrane phospholipase A from Acinetobacter sp. HO1-N. An outer membrane phospholipase A active against phosphatidylglycerol and phosphatidylethanolamine was characterized from Acinetobacter sp. HO1-N.

PMID:30759

Managing tardive dyskinesia.

Tardive dyskinesia, a delayed side effect of neuroleptic drugs, requires early recognition and a systematic treatment plan. An outline is presented which offers guidelines for management strategies and drug treatments, along with a summary of recent developments.

Managing tardive dyskinesia. Tardive dyskinesia, a delayed side effect of neuroleptic drugs, requires early recognition and a systematic treatment plan. An outline is presented which offers guidelines for management strategies and drug treatments, along with a summary of recent developments.

PMID:30760

Use of saliva lithium determinations for monitoring lithium therapy.

During acute and chronic administrations of lithium, 25 patients were studied to determine the effect of other psychotropic drugs on the plasma-saliva lithium concentration correlations. Changes, even discontinuation, in either tricyclic antidepressants or neuroleptics did not affect the plasma-saliva ratio which had an overall correlation coefficient of r = 0.79 (p less than 0.01). The relationship using linear regression analysis was described by the equation, y = 2.27x--0.45. Individual patients' plasma-salivary relations were described by this equation in 87% of cases. The study extends the usefulness of these determinations to include patients on lithium and neuroleptics or tricyclic antidepressants.

Use of saliva lithium determinations for monitoring lithium therapy. During acute and chronic administrations of lithium, 25 patients were studied to determine the effect of other psychotropic drugs on the plasma-saliva lithium concentration correlations. Changes, even discontinuation, in either tricyclic antidepressants or neuroleptics did not affect the plasma-saliva ratio which had an overall correlation coefficient of r = 0.79 (p less than 0.01). The relationship using linear regression analysis was described by the equation, y = 2.27x--0.45. Individual patients' plasma-salivary relations were described by this equation in 87% of cases. The study extends the usefulness of these determinations to include patients on lithium and neuroleptics or tricyclic antidepressants.

PMID:30761

Comparative metabolism of lorazepam in man and four animal species.

The metabolic disposition of lorazepam (Wy-4036) in man, dog, cat, rat and miniature swine is compared. Except in the cat, absorption of lorazepam is rapid in these species. Absorption in humans is nearly complete. Lorazepam glucuronide is the major metabolite in all species except the rat in which a dihydrodiol derivative is the main product of lorazepam biotransformation. Lorazepam glucuronide, which has no demonstrable CNS activity, is also present in the plasma of all species investigated. The concentrations of lorazepam in rat brain correlate well with those in plasma but are about three times higher. The urinary route of excretion predominates in man, dog and miniature swine while in the rat the bulk of the drug-related material is eliminated with the feces as a consequence of biliary excretion.

Comparative metabolism of lorazepam in man and four animal species. The metabolic disposition of lorazepam (Wy-4036) in man, dog, cat, rat and miniature swine is compared. Except in the cat, absorption of lorazepam is rapid in these species. Absorption in humans is nearly complete. Lorazepam glucuronide is the major metabolite in all species except the rat in which a dihydrodiol derivative is the main product of lorazepam biotransformation. Lorazepam glucuronide, which has no demonstrable CNS activity, is also present in the plasma of all species investigated. The concentrations of lorazepam in rat brain correlate well with those in plasma but are about three times higher. The urinary route of excretion predominates in man, dog and miniature swine while in the rat the bulk of the drug-related material is eliminated with the feces as a consequence of biliary excretion.

PMID:30762

Clinical pharmacokinetics of lorazepam: a review.

The clinical pharmacokinetics of lorazepam, a 3-hydroxy, 1,4-benzodiazepine, indicate that it is rapidly and readily absorbed, reaching peak concentrations in the blood proportional to the dose approximately 2 hours after oral administration. Blood levels decline thereafter, with an elimination half-life of about 12 hrs. Conjugation with glucuronic acid to form inactive lorazepam glucuronide is the major metabolic pathway. Seventy (70) to 75% of the administered dose is excreted as the glucuronide conjugate in the urine. On multiple-dose regimens, steady state blood levels directly proportional to the daily dose occur within 2--3 days and are maintained after several months of continuous treatment. The active drug and the glucuronide conjugate are completely eliminated from the blood within 1 week following the last dose.

Clinical pharmacokinetics of lorazepam: a review. The clinical pharmacokinetics of lorazepam, a 3-hydroxy, 1,4-benzodiazepine, indicate that it is rapidly and readily absorbed, reaching peak concentrations in the blood proportional to the dose approximately 2 hours after oral administration. Blood levels decline thereafter, with an elimination half-life of about 12 hrs. Conjugation with glucuronic acid to form inactive lorazepam glucuronide is the major metabolic pathway. Seventy (70) to 75% of the administered dose is excreted as the glucuronide conjugate in the urine. On multiple-dose regimens, steady state blood levels directly proportional to the daily dose occur within 2--3 days and are maintained after several months of continuous treatment. The active drug and the glucuronide conjugate are completely eliminated from the blood within 1 week following the last dose.

PMID:30763

Clinical assessment of the safety and efficacy of lorazepam, a new benzodiazepine derivative, in the treatment of anxiety.

In a four-week double-blind study of 68 adult outpatients, lorazepam a new benzodiazepine, administered at an average total daily dosage level of 3.1 mg on a b.i.d. regimen, was clearly superior to placebo in the treatment of neurotic anxiety and its related symptoms. The lorazepam-treated group showed significantly greater improvement than the placebo-treated group (both clinically and statistically), as evidenced by the greater changes on the physician-rated Global Scale as well as by the greater changes in almost all categories on the physician-rated Hamilton Anxiety Scale and the patient-rated Lipman-Rickels 35-Item Self-Rating Scale. There were no clinically significant changes in vital signs or laboratory values and only one side effect, urinary retention (resolved without discontinuing the drug), was reported.

Clinical assessment of the safety and efficacy of lorazepam, a new benzodiazepine derivative, in the treatment of anxiety. In a four-week double-blind study of 68 adult outpatients, lorazepam a new benzodiazepine, administered at an average total daily dosage level of 3.1 mg on a b.i.d. regimen, was clearly superior to placebo in the treatment of neurotic anxiety and its related symptoms. The lorazepam-treated group showed significantly greater improvement than the placebo-treated group (both clinically and statistically), as evidenced by the greater changes on the physician-rated Global Scale as well as by the greater changes in almost all categories on the physician-rated Hamilton Anxiety Scale and the patient-rated Lipman-Rickels 35-Item Self-Rating Scale. There were no clinically significant changes in vital signs or laboratory values and only one side effect, urinary retention (resolved without discontinuing the drug), was reported.

PMID:30764

Pharmacology of lorazepam.

Lorazepam reduced conflict behavior in rats and monkeys, inhibited pentylenetetrazol- and electroshock-induced convulsions, suppressed footshock-induced fighting behavior, and prevented morphine-induced stimulation in mice at lower doses than other benzodiazepines tested. This behavioral profile suggests that lorazepam will be an active anti-anxiety agent in man at low doses.

Pharmacology of lorazepam. Lorazepam reduced conflict behavior in rats and monkeys, inhibited pentylenetetrazol- and electroshock-induced convulsions, suppressed footshock-induced fighting behavior, and prevented morphine-induced stimulation in mice at lower doses than other benzodiazepines tested. This behavioral profile suggests that lorazepam will be an active anti-anxiety agent in man at low doses.

PMID:30765

Studies with oral lorazepam in anxiety neurosis associated with depressive symptomatology.

Twelve studies were undertaken under a common four-week protocol to investigate the efficacy of lorazepam compared with placebo in reducing the severity of moderate to severe anxiety in 264 patients also having significant depressive symptomatology. Analysis of the results indicated that lorazepam gave generally better anxiety relief than placebo; in the majority of comparisons the differences were substantial enough to be both statistically and clinically significant. No data were obtained evidencing significant toxicity in either treatment group.

Studies with oral lorazepam in anxiety neurosis associated with depressive symptomatology. Twelve studies were undertaken under a common four-week protocol to investigate the efficacy of lorazepam compared with placebo in reducing the severity of moderate to severe anxiety in 264 patients also having significant depressive symptomatology. Analysis of the results indicated that lorazepam gave generally better anxiety relief than placebo; in the majority of comparisons the differences were substantial enough to be both statistically and clinically significant. No data were obtained evidencing significant toxicity in either treatment group.

PMID:30766

Antianxiety effects of lorazepam in patients with cardiovascular symptomatology.

Lorazepam was administered to 38 patients with moderate to severe anxiety associated with cardiovascular symptomatology. A comparable group of patients on placebo (35) served as controls in this 4-week study. Average dosage was 3 mg/day given as 2 mg in the evening and 1 mg in the morning. The Global response, Hamilton Anxiety Rating Scale scores, and 35-Item Self-Rating Scale scores showed lorazepam to be significantly more effective in relieving anxiety than placebo, both clinically and statistically. Adverse reactions were transient and tolerable, and were reported in only 2 patients on lorazepam.

Antianxiety effects of lorazepam in patients with cardiovascular symptomatology. Lorazepam was administered to 38 patients with moderate to severe anxiety associated with cardiovascular symptomatology. A comparable group of patients on placebo (35) served as controls in this 4-week study. Average dosage was 3 mg/day given as 2 mg in the evening and 1 mg in the morning. The Global response, Hamilton Anxiety Rating Scale scores, and 35-Item Self-Rating Scale scores showed lorazepam to be significantly more effective in relieving anxiety than placebo, both clinically and statistically. Adverse reactions were transient and tolerable, and were reported in only 2 patients on lorazepam.

PMID:30767

The effect of lorazepam on hypertension-associated anxiety: a double-blind study.

Sixty-two adults with a current diagnosis of significant hypertension and accompanying moderate to severe anxiety were medicated with lorazepam or with placebo for a period of 4 weeks. The patients were assessed by 7 cardiologists under double-blind conditions and the results pooled. Symptoms of anxiety were quantified using a Global Physician Rating, the Hamilton Anxiety Scale and a Patient Self-Rating Scale. The symptoms of anxiety associated with hypertension were significantly relieved by lorazepam in comparison to placebo. Most lorazepam patients were controlled with 3 mg/day; except for 1 patient, side effects were mild and transient.

The effect of lorazepam on hypertension-associated anxiety: a double-blind study. Sixty-two adults with a current diagnosis of significant hypertension and accompanying moderate to severe anxiety were medicated with lorazepam or with placebo for a period of 4 weeks. The patients were assessed by 7 cardiologists under double-blind conditions and the results pooled. Symptoms of anxiety were quantified using a Global Physician Rating, the Hamilton Anxiety Scale and a Patient Self-Rating Scale. The symptoms of anxiety associated with hypertension were significantly relieved by lorazepam in comparison to placebo. Most lorazepam patients were controlled with 3 mg/day; except for 1 patient, side effects were mild and transient.

PMID:30768

A clinical assessment of lorazepam in the treatment of anxiety associated with gastrointestinal symptomatology.

The effectiveness of lorazepam was assessed under double-blind conditions in 70 ambulant patients suffering from anxiety associated with gastrointestinal symptomatology. In this 4-week study, the usual daily dose of lorazepam, 3.0 mg given in a b.i.d. regimen, produced a greater decrease in symptoms associated with anxiety than placebo at almost all evaluation periods, as indicated by Kruskal-Wallis analyses of Global, Hamilton, and 35-Item ratings--a decrease which was clinically and statistically significant. In addition, lorazepam was well accepted and well tolerated by the majority of patients and was compatible with concomitant medications. Side effects were infrequent and usually controlled by dosage adjustment.

A clinical assessment of lorazepam in the treatment of anxiety associated with gastrointestinal symptomatology. The effectiveness of lorazepam was assessed under double-blind conditions in 70 ambulant patients suffering from anxiety associated with gastrointestinal symptomatology. In this 4-week study, the usual daily dose of lorazepam, 3.0 mg given in a b.i.d. regimen, produced a greater decrease in symptoms associated with anxiety than placebo at almost all evaluation periods, as indicated by Kruskal-Wallis analyses of Global, Hamilton, and 35-Item ratings--a decrease which was clinically and statistically significant. In addition, lorazepam was well accepted and well tolerated by the majority of patients and was compatible with concomitant medications. Side effects were infrequent and usually controlled by dosage adjustment.

PMID:30769

Lorazepam in anxiety associated with chronic enteritis and ulcerative colitis.

Using a common protocol, 9 gastroenterologists assessed the comparative antianxiety efficacy of lorazepam and placebo under double-blind conditions in 48 patients with moderate to severe anxiety associated with chronic enteritis and ulcerative colitis. The initial dose of lorazepam was 3 mg per day given b.i.d., 2 mg h.s. and 1 mg a.m.; the duration of treatment was 4 weeks. The physician-rated Global and Hamilton and patient-rated 35-Item Scales were used. Efficacy was analyzed from the results of the pooled patient data. By all 3 rating scales and at virtually all times of assessment, lorazepam was associated with statistically significantly greater improvement in symptoms related to anxiety associated with chronic enteritis and ulcerative colitis than was placebo. Side effects in general were infrequent. (J Clin Psychiatry 39:[No. 10--2] 53--57, 1978).

Lorazepam in anxiety associated with chronic enteritis and ulcerative colitis. Using a common protocol, 9 gastroenterologists assessed the comparative antianxiety efficacy of lorazepam and placebo under double-blind conditions in 48 patients with moderate to severe anxiety associated with chronic enteritis and ulcerative colitis. The initial dose of lorazepam was 3 mg per day given b.i.d., 2 mg h.s. and 1 mg a.m.; the duration of treatment was 4 weeks. The physician-rated Global and Hamilton and patient-rated 35-Item Scales were used. Efficacy was analyzed from the results of the pooled patient data. By all 3 rating scales and at virtually all times of assessment, lorazepam was associated with statistically significantly greater improvement in symptoms related to anxiety associated with chronic enteritis and ulcerative colitis than was placebo. Side effects in general were infrequent. (J Clin Psychiatry 39:[No. 10--2] 53--57, 1978).

PMID:30771

Reversible conversion from Ca(2)+-ATPase activity to Mg(2)+- and Mn(2)+-ATPase activities of coupling factor purified from acetone powder of Rhodospirillum rubrum chromatophores.

It is known that the coupling factor purified from the acetone powder of chromatophores from Rhodospirillum rubrum shows ATPase activity in the presence of Ca(2)+, but not in the presence of Mg(2)+ or Mn(2)+. The present study deals with conditions, under which the Ca(2)+-ATPase activity is reversibly converted into Mg(2)+- and Mn(2)+-ATPase activites with the purified coupling factor. 1. Of the pH indicators tested, 6 kinds coverted the Ca(2)+-ATPase activity into Mg(2)+- and Mn(2)+-ATPase activities in the order, ethyl orange greater than tropaeolin 000 greater than or equal to metanil yellow greater than tropaeolin 00 greater than ethyl red greater than or equal to bromthymol blue. 2. Of the detergents tested, those other than Triton X-100 and Brij 58 caused the conversion described above; dodecylsulfonate was most effective, whereas dodecylpyridinium chloride was moderately effective. 3. 2,4-Dinitrophenol stimulated approximately two-fold the Ca(2)+-ATPase activity, but not the Mg(2)+- or Mn(2)+-ATPase activity at all. However, in the presence of dodecylpyridinium chloride, the pH indicator remarkably stimulated the Mg(2)+- and Mn(2)+-ATPase activities, accompanied with a partial inhibition of the Ca(2)+-ATPase activity. Methyl red and ethyl red showed similar effects. 4. All the nucleoside triphosphates tested can serve as the substrate. ATP was most effective for the Ca(2)+-ATPase activity, whereas dATP was most effective for the Mg(2)+- and Mn(2)+-ATPase activities induced by ethyl orange. 5. In the presence of ethyl orange, the ATPase activity was induced by various divalent cations in the following order of effectiveness, Mg(2)+ greater than Zn(2)+ greater than CO(2)+ greater than Mn(2)+ greater than Ni(2)+. 6. The mechanism of the reversible conversion from the Ca(2)+-ATPase activity to the Mg(2)+- and Mn(2)+-ATPase activities by pH indicators and detergents is discussed.

Reversible conversion from Ca(2)+-ATPase activity to Mg(2)+- and Mn(2)+-ATPase activities of coupling factor purified from acetone powder of Rhodospirillum rubrum chromatophores. It is known that the coupling factor purified from the acetone powder of chromatophores from Rhodospirillum rubrum shows ATPase activity in the presence of Ca(2)+, but not in the presence of Mg(2)+ or Mn(2)+. The present study deals with conditions, under which the Ca(2)+-ATPase activity is reversibly converted into Mg(2)+- and Mn(2)+-ATPase activites with the purified coupling factor. 1. Of the pH indicators tested, 6 kinds coverted the Ca(2)+-ATPase activity into Mg(2)+- and Mn(2)+-ATPase activities in the order, ethyl orange greater than tropaeolin 000 greater than or equal to metanil yellow greater than tropaeolin 00 greater than ethyl red greater than or equal to bromthymol blue. 2. Of the detergents tested, those other than Triton X-100 and Brij 58 caused the conversion described above; dodecylsulfonate was most effective, whereas dodecylpyridinium chloride was moderately effective. 3. 2,4-Dinitrophenol stimulated approximately two-fold the Ca(2)+-ATPase activity, but not the Mg(2)+- or Mn(2)+-ATPase activity at all. However, in the presence of dodecylpyridinium chloride, the pH indicator remarkably stimulated the Mg(2)+- and Mn(2)+-ATPase activities, accompanied with a partial inhibition of the Ca(2)+-ATPase activity. Methyl red and ethyl red showed similar effects. 4. All the nucleoside triphosphates tested can serve as the substrate. ATP was most effective for the Ca(2)+-ATPase activity, whereas dATP was most effective for the Mg(2)+- and Mn(2)+-ATPase activities induced by ethyl orange. 5. In the presence of ethyl orange, the ATPase activity was induced by various divalent cations in the following order of effectiveness, Mg(2)+ greater than Zn(2)+ greater than CO(2)+ greater than Mn(2)+ greater than Ni(2)+. 6. The mechanism of the reversible conversion from the Ca(2)+-ATPase activity to the Mg(2)+- and Mn(2)+-ATPase activities by pH indicators and detergents is discussed.

PMID:30772

Nerve growth factor-mediated induction of tyrosine hydroxylase in rat superior cervical ganglia in vitro.

Exposure of rat sympathetic ganglia to 3 microgram/ml of 2.5 S nerve growth factor (NGF) resulted in a 100% increase in tyrosine hydroxylase activity within 48 h. Pulselabeling of proteins with [3H]leucine, followed by immunoprecipitation with antibodies to tyrosine hydorxylase and isolation of the precipitated enzyme by gel electrophoresis, demonstrated that the increase in tyrosine hydroxylase activity was due to enhanced de novo synthesis. The incorporation of [3H]leucine into tyrosine hydroxylase was increased by 150% compared to a 17% increase in total protein synthesis, which was not statistically significant. The fact that the half-life of pulse-labeled tyrosine hydroxylase was the same for NGF-treated and control organ cultures of superior cervical ganglia excludes the possibility that enhanced tyrosine hydroxylase labeling by NGF is due to decreased degradation. We conclude that, without modulatory factors which play a role in vivo, NGF can enhance the synthesis of tyrosine hydroxylase in sympathetic ganglia in vitro, provided organ culture conditions which permit optimal survival of adrenergic neurons are selected.

Nerve growth factor-mediated induction of tyrosine hydroxylase in rat superior cervical ganglia in vitro. Exposure of rat sympathetic ganglia to 3 microgram/ml of 2.5 S nerve growth factor (NGF) resulted in a 100% increase in tyrosine hydroxylase activity within 48 h. Pulselabeling of proteins with [3H]leucine, followed by immunoprecipitation with antibodies to tyrosine hydorxylase and isolation of the precipitated enzyme by gel electrophoresis, demonstrated that the increase in tyrosine hydroxylase activity was due to enhanced de novo synthesis. The incorporation of [3H]leucine into tyrosine hydroxylase was increased by 150% compared to a 17% increase in total protein synthesis, which was not statistically significant. The fact that the half-life of pulse-labeled tyrosine hydroxylase was the same for NGF-treated and control organ cultures of superior cervical ganglia excludes the possibility that enhanced tyrosine hydroxylase labeling by NGF is due to decreased degradation. We conclude that, without modulatory factors which play a role in vivo, NGF can enhance the synthesis of tyrosine hydroxylase in sympathetic ganglia in vitro, provided organ culture conditions which permit optimal survival of adrenergic neurons are selected.

PMID:30773

Partial reactions of aminoacyl-tRNA synthetases as functions of pH.

The effect of pH on the properties of the partial reactions of arginyl-tRNA synthetase of E. coli has been investigated. V max of pyrophosphorolysis of arginyl adenylate has a pH optimum at pH 6.1, whereas V max of the transfer of arginine to tRNA has a pH optimum of 8.2. These values correlate with the pH optima of the ATP:PPi exchange and the overall esterification reaction, respectively. Only the pyrophosphorolysis reaction requires a divalent cation; transfer proceeds in the presence of EDTA. Inorganic pyrophosphate inhibits the transfer reaction to an extent independent of the concentration of tRNA; the maximum inhibition is a function of pH, corresponding to the relative rate of pyrophosphorolysis of the common intermediate compared with the rate of transfer. These results show that different groups on the enzyme participate in the rate-limiting steps of the two partial reactions and that these partial reactions have properties consistent with their participation in the overall esterification of arginine with tRNA.

Partial reactions of aminoacyl-tRNA synthetases as functions of pH. The effect of pH on the properties of the partial reactions of arginyl-tRNA synthetase of E. coli has been investigated. V max of pyrophosphorolysis of arginyl adenylate has a pH optimum at pH 6.1, whereas V max of the transfer of arginine to tRNA has a pH optimum of 8.2. These values correlate with the pH optima of the ATP:PPi exchange and the overall esterification reaction, respectively. Only the pyrophosphorolysis reaction requires a divalent cation; transfer proceeds in the presence of EDTA. Inorganic pyrophosphate inhibits the transfer reaction to an extent independent of the concentration of tRNA; the maximum inhibition is a function of pH, corresponding to the relative rate of pyrophosphorolysis of the common intermediate compared with the rate of transfer. These results show that different groups on the enzyme participate in the rate-limiting steps of the two partial reactions and that these partial reactions have properties consistent with their participation in the overall esterification of arginine with tRNA.

PMID:30774

Regulation of rat liver acetyl-CoA carboxylase. Stimulation of phosphorylation and subsequent inactivation of liver acetyl-CoA carboxylase by cyclic 3':5'-monophosphate and effect on the structure of the enzyme.

The effects of citrate and cyclic AMP on the rate and degree of phosphorylation and inactivation of rat liver acetyl-CoA carboxylase were examined. High citrate concentrations (10 to 20 mM), which are generally used to stabilize and activate the enzyme, inhibit phosphorylation and inactivation of carboxylase. At lower concentrations of citrate, the rate and degree of phosphorylation are increased. Furthermore, phosphorylation and enzyme inactivation are affected by cyclic AMP under these conditions. At high citrate concentrations, cyclic AMP has little or no effect on inactivation and phosphorylation of acetyl-CoA carboxylase. Phosphorlation and inactivation of carboxylase is accompanied by depolymerization of the polymeric form of the enzyme into intermediate and protomeric forms. Depolymerization of carboxylase requires the transfer of the gamma-phosphate group from ATP to carboxylase. Inactivation occurs in the absence of CO2, which indicates that phosphorylation of the enzyme is the cause of inactivation and depolymerization, i.e. carboxylation of the enzyme is not responsible for inactivation of the enzyme.

Regulation of rat liver acetyl-CoA carboxylase. Stimulation of phosphorylation and subsequent inactivation of liver acetyl-CoA carboxylase by cyclic 3':5'-monophosphate and effect on the structure of the enzyme. The effects of citrate and cyclic AMP on the rate and degree of phosphorylation and inactivation of rat liver acetyl-CoA carboxylase were examined. High citrate concentrations (10 to 20 mM), which are generally used to stabilize and activate the enzyme, inhibit phosphorylation and inactivation of carboxylase. At lower concentrations of citrate, the rate and degree of phosphorylation are increased. Furthermore, phosphorylation and enzyme inactivation are affected by cyclic AMP under these conditions. At high citrate concentrations, cyclic AMP has little or no effect on inactivation and phosphorylation of acetyl-CoA carboxylase. Phosphorlation and inactivation of carboxylase is accompanied by depolymerization of the polymeric form of the enzyme into intermediate and protomeric forms. Depolymerization of carboxylase requires the transfer of the gamma-phosphate group from ATP to carboxylase. Inactivation occurs in the absence of CO2, which indicates that phosphorylation of the enzyme is the cause of inactivation and depolymerization, i.e. carboxylation of the enzyme is not responsible for inactivation of the enzyme.

PMID:30775

Effect of epinephrine on acetyl-CoA carboxylase in rat epididymal fat tissue.

If acetyl-CoA carboxylase in epididymal fat tissue is subject to control by convalent modification as in the case of the liver enzyme, catalytically different forms of carboxylase should exist, independent of polymerization. By treating epididymal fat tissue in culture with epinephrine, we have demonstrated catalytically less active forms of acetyl-CoA carboxylase. The catalytically less active forms of the enzyme reacted to antibody with the same efficiency as the active form of carboxylase. However, the less active enzyme formed by epinephrine treatment of tissues has a sedimentation constant of 30 to 35 S, whereas that of the enzyme from control tissue is 45 S. Incubation of the less active forms of the carboxylase with 10 mM citrate and up to 10 mg/ml of bovine serum albumin activated the enzyme without any change in the sedimentation constant. Therefore, the less active forms of the carboxylase formed as a result of epinephrine treatment are not due to the depolymerization of polymeric forms (45 S) to the protomeric forms (17 to 20 S), but to the formation of intermediate species of carboxylase which cannot form polymeric enzyme (45 S) in the presence of high concentrations of citrate.

Effect of epinephrine on acetyl-CoA carboxylase in rat epididymal fat tissue. If acetyl-CoA carboxylase in epididymal fat tissue is subject to control by convalent modification as in the case of the liver enzyme, catalytically different forms of carboxylase should exist, independent of polymerization. By treating epididymal fat tissue in culture with epinephrine, we have demonstrated catalytically less active forms of acetyl-CoA carboxylase. The catalytically less active forms of the enzyme reacted to antibody with the same efficiency as the active form of carboxylase. However, the less active enzyme formed by epinephrine treatment of tissues has a sedimentation constant of 30 to 35 S, whereas that of the enzyme from control tissue is 45 S. Incubation of the less active forms of the carboxylase with 10 mM citrate and up to 10 mg/ml of bovine serum albumin activated the enzyme without any change in the sedimentation constant. Therefore, the less active forms of the carboxylase formed as a result of epinephrine treatment are not due to the depolymerization of polymeric forms (45 S) to the protomeric forms (17 to 20 S), but to the formation of intermediate species of carboxylase which cannot form polymeric enzyme (45 S) in the presence of high concentrations of citrate.

PMID:30777

The unfolding of the cytochromes c in methanol and acid.

The cytochromes c are a family of hemoproteins that share a number of structural features: a thioether linkage between the protein and the heme, histidine and methionine as the fifth and sixth iron ligands, and a tertiary structure known as the "cytochrome fold." These proteins follow a common mechanism of equilibrium unfolding in methanol and acid, differing only in their reactivity to the denaturing conditions. The reduced cytochromes c exhibit an increased conformational stability which is consistent with the presence of a strengthened iron-methionine linkage in the reduced state.

The unfolding of the cytochromes c in methanol and acid. The cytochromes c are a family of hemoproteins that share a number of structural features: a thioether linkage between the protein and the heme, histidine and methionine as the fifth and sixth iron ligands, and a tertiary structure known as the "cytochrome fold." These proteins follow a common mechanism of equilibrium unfolding in methanol and acid, differing only in their reactivity to the denaturing conditions. The reduced cytochromes c exhibit an increased conformational stability which is consistent with the presence of a strengthened iron-methionine linkage in the reduced state.

PMID:30778

Restoration of the responsiveness of purified guanylate cyclase to nitrosoguanidine, nitric oxide, and related activators by heme and hemeproteins. Evidence for involvement of the paramagnetic nitrosyl-heme complex in enzyme activation.

Purification of soluble guanylate cyclase activity from rat liver resulted in loss of enzyme responsiveness to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), nitroprusside, nitrite, and NO. Responses were restored by addition of heat-treated hepatic supernatant fraction, implying a requirement for heat-stable soluble factor(s) in the optimal expression of the actions of the activators. Addition of free hematin, hemoglobin, methemoglobin, active or heat-inactivated catalase partially restores responsiveness of purified guanylate cyclase to MNNG, NO, nitrite, and nitroprusside. These responses were markedly potentiated by the presence of an appropriate concentration of reducing agent (dithiothreitol, ascorbate, cysteine, or glutathione), which maintains heme iron in the ferro form and favors formation of paramagnetic nitrosyl . heme complexes from the activators. High concentrations of heme or reducing agents were inhibitory, and heme was not required for the expression of the stimulatory effects of Mn2+ or Mg2+ on purified guanylate cyclase. Preformed nitrosyl hemoglobin (10 micron) increased activity of the purified enzyme 10- to 20-fold over basal with Mn2+ as the metal cofactor and 90- to 100-fold with Mg2+. Purified guanylate cyclase was more sensitive to preformed NO-hemoglobin (minimally effective concentration, 0.1 micron) than to MNNG (1 micron), nitroprusside (50 micron), or nitrite (1 mM). A reducing agent was not required for optimal stimulation of guanylate cyclase by NO-hemoglobin. Maximal NO-hemoglobin-responsive guanylate cyclase was not further increased by subsequent addition of NO, MNNG, nitrite, or nitroprusside. Activation by each agent resulted in analogous alterations in the Mn2+ and Mg2+ requirements of enzyme activity, and responses were inhibited by the thiol-blocking agents N-ethylmaleimide, arsenite, or iodoacetamide. The results suggest that NO-hemoglobin, MNNG, NO, nitrite, and nitroprusside activate guanylate cyclase through similar mechanisms. The stimulatory effects of preformed NO-hemoglobin combined with the clear requirements for heme plus a reducing agent in the optimal expression of the actions of MNNG, NO, and related agents are consistent with a role for the paramagnetic nitrosyl . heme complex in the activation of guanylate cyclase.

Restoration of the responsiveness of purified guanylate cyclase to nitrosoguanidine, nitric oxide, and related activators by heme and hemeproteins. Evidence for involvement of the paramagnetic nitrosyl-heme complex in enzyme activation. Purification of soluble guanylate cyclase activity from rat liver resulted in loss of enzyme responsiveness to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), nitroprusside, nitrite, and NO. Responses were restored by addition of heat-treated hepatic supernatant fraction, implying a requirement for heat-stable soluble factor(s) in the optimal expression of the actions of the activators. Addition of free hematin, hemoglobin, methemoglobin, active or heat-inactivated catalase partially restores responsiveness of purified guanylate cyclase to MNNG, NO, nitrite, and nitroprusside. These responses were markedly potentiated by the presence of an appropriate concentration of reducing agent (dithiothreitol, ascorbate, cysteine, or glutathione), which maintains heme iron in the ferro form and favors formation of paramagnetic nitrosyl . heme complexes from the activators. High concentrations of heme or reducing agents were inhibitory, and heme was not required for the expression of the stimulatory effects of Mn2+ or Mg2+ on purified guanylate cyclase. Preformed nitrosyl hemoglobin (10 micron) increased activity of the purified enzyme 10- to 20-fold over basal with Mn2+ as the metal cofactor and 90- to 100-fold with Mg2+. Purified guanylate cyclase was more sensitive to preformed NO-hemoglobin (minimally effective concentration, 0.1 micron) than to MNNG (1 micron), nitroprusside (50 micron), or nitrite (1 mM). A reducing agent was not required for optimal stimulation of guanylate cyclase by NO-hemoglobin. Maximal NO-hemoglobin-responsive guanylate cyclase was not further increased by subsequent addition of NO, MNNG, nitrite, or nitroprusside. Activation by each agent resulted in analogous alterations in the Mn2+ and Mg2+ requirements of enzyme activity, and responses were inhibited by the thiol-blocking agents N-ethylmaleimide, arsenite, or iodoacetamide. The results suggest that NO-hemoglobin, MNNG, NO, nitrite, and nitroprusside activate guanylate cyclase through similar mechanisms. The stimulatory effects of preformed NO-hemoglobin combined with the clear requirements for heme plus a reducing agent in the optimal expression of the actions of MNNG, NO, and related agents are consistent with a role for the paramagnetic nitrosyl . heme complex in the activation of guanylate cyclase.

PMID:30780

The sensitivity of hemoglobin oxygen affinity to diphosphoglycerate and the characteristic pH of methemoglobin.

The sensitivity of the oxygen affinity of a hemoglobin to 2,3-diphosphoglyceric acid concentration has been defined as the change in log1/2O2 (deltalogp1/2O2) which results from saturating the hemoglobin with 2,3-diphosphoglyceric acid. The sensitivity varies from one hemoglobin species to another and is linearly rated to the difference in the logarithm of the binding constants of 2,3-diphosphoglyceric acid to deoxy- and oxyhemoglobin, the characteristic pH (pHch), and inversely proportional to the magnitude of the alkaline Bohr effect measured in a saturating amount of 2,3-diphosphoglyceric acid. Its magnitude is higher in large animals than in small animals and varies linearly with the charged amino acid composition of the hemoglobin. The charged amino acid residues must have been selected for in mammals with high metabolic needs and against in animals with low metabolic needs. Variability in the effect of 2,3-diphosphoglyceric acid on the oxygen transport in the different animal hemoglobins must therefore be the result of a positive Darwinian Selection of the charged amino acid residues in their hemoglobins. Furthermore, all the charged groups and not those at the binding site alone, affect the 2,3-diphosphoglyceric acid binding constant of a hemoglobin.

The sensitivity of hemoglobin oxygen affinity to diphosphoglycerate and the characteristic pH of methemoglobin. The sensitivity of the oxygen affinity of a hemoglobin to 2,3-diphosphoglyceric acid concentration has been defined as the change in log1/2O2 (deltalogp1/2O2) which results from saturating the hemoglobin with 2,3-diphosphoglyceric acid. The sensitivity varies from one hemoglobin species to another and is linearly rated to the difference in the logarithm of the binding constants of 2,3-diphosphoglyceric acid to deoxy- and oxyhemoglobin, the characteristic pH (pHch), and inversely proportional to the magnitude of the alkaline Bohr effect measured in a saturating amount of 2,3-diphosphoglyceric acid. Its magnitude is higher in large animals than in small animals and varies linearly with the charged amino acid composition of the hemoglobin. The charged amino acid residues must have been selected for in mammals with high metabolic needs and against in animals with low metabolic needs. Variability in the effect of 2,3-diphosphoglyceric acid on the oxygen transport in the different animal hemoglobins must therefore be the result of a positive Darwinian Selection of the charged amino acid residues in their hemoglobins. Furthermore, all the charged groups and not those at the binding site alone, affect the 2,3-diphosphoglyceric acid binding constant of a hemoglobin.

PMID:30782

Platelet derived growth factor(s) for a hormone-responsive rat mammary tumor cell line.

Mammary tumor cell growth factor(s) has been identified in extracts of platelets from both male and female rats, as well as in extracts prepared from pooled outdated human platelets. When assayed by the growth promotion of MTW9/PL rat mammary tumor cells in culture, platelet extracts alone were able to support growth 50--75% as well as whole serum. The mitogenic activity from crude human platelet lysates was shown to be trypsin sensitive, relatively stable to extremes of pH, labile to heat treatment at 70 degrees, non-dialysable, ammonium sulfate precipitable, not removed by 56 degrees charcoal treatment, and of apparent molecular weight of 30,000 to 50,000 daltons as estimated by G-100 Sephadex chromatography. The platelet derived mammary growth factor activity was not replaced or potentiated by thrombin or known hormones and growth factors such as prolactin, insulin, 17-beta-estradiol, progesterone, hydrocortisone, L-thyroxine, and mouse epidermal growth factor. The experimental report demonstrates that platelets are a rich source growth factor activity for rat epithelial mammary tumor cells, and that the activity appears to be a polypeptide(s) different from other mitogenic activities known to influence growth of mammary tissue.

Platelet derived growth factor(s) for a hormone-responsive rat mammary tumor cell line. Mammary tumor cell growth factor(s) has been identified in extracts of platelets from both male and female rats, as well as in extracts prepared from pooled outdated human platelets. When assayed by the growth promotion of MTW9/PL rat mammary tumor cells in culture, platelet extracts alone were able to support growth 50--75% as well as whole serum. The mitogenic activity from crude human platelet lysates was shown to be trypsin sensitive, relatively stable to extremes of pH, labile to heat treatment at 70 degrees, non-dialysable, ammonium sulfate precipitable, not removed by 56 degrees charcoal treatment, and of apparent molecular weight of 30,000 to 50,000 daltons as estimated by G-100 Sephadex chromatography. The platelet derived mammary growth factor activity was not replaced or potentiated by thrombin or known hormones and growth factors such as prolactin, insulin, 17-beta-estradiol, progesterone, hydrocortisone, L-thyroxine, and mouse epidermal growth factor. The experimental report demonstrates that platelets are a rich source growth factor activity for rat epithelial mammary tumor cells, and that the activity appears to be a polypeptide(s) different from other mitogenic activities known to influence growth of mammary tissue.

PMID:30784

The relationship between guilt and quality of drug experiences.

Consistent with predictions from Mosher's (1966) guilt construct, the present study found that high guilt males, compared with low guilt Ss, reported significantly less use of marijuana, depressant, stimulant and hallucinogenic drugs. Among all Ss who reported at least one use within each drug category, high guilt Ss rated their experiences as less pleasant and reported a higher frequency of "bad trips" than did low guilt individuals. Overall, these results support Mosher's contention that high vs. low guilt Ss are less likely to engage in culturally prohibited activities such as drug use and are more likely to have unpleasant experiences resulting from guilt when such activities are pursued.

The relationship between guilt and quality of drug experiences. Consistent with predictions from Mosher's (1966) guilt construct, the present study found that high guilt males, compared with low guilt Ss, reported significantly less use of marijuana, depressant, stimulant and hallucinogenic drugs. Among all Ss who reported at least one use within each drug category, high guilt Ss rated their experiences as less pleasant and reported a higher frequency of "bad trips" than did low guilt individuals. Overall, these results support Mosher's contention that high vs. low guilt Ss are less likely to engage in culturally prohibited activities such as drug use and are more likely to have unpleasant experiences resulting from guilt when such activities are pursued.

PMID:30783

Cobalamin binding and cobalamin-dependent enzyme activity in normal and mutant human fibroblasts.

We have studied the intracellular binding of radioactive cobalamin by normal cultured human fibroblasts grown in medium containing [(57)Co]-cobalamin. We have also assessed the significance of defects in this binding activity exhibited by two classes of human mutants (cbl C and cbl D) each characterized by pleiotropic deficiencies in the accumulation and retention of cobalamin, in the synthesis of cobalamin coenzymes, and accordingly, in the holoenzyme activities of both cobalamin-dependent enzymes, 5-methyltetrahydrofolate:homocysteine methyltransferase and methylmalonyl-CoA mutase. Based on the coincidence of [(57)Co]cobalamin binding and cobalamin-dependent enzyme activities after Sephadex G-150 chromatography and polyacrylamide gel electrophoresis, we conclude that, as in rat liver, the intracellular binding of labeled cobalamin by normal fibroblasts reflects the attachment of the vitamin to the cobalamin-dependent methyltransferase and mutase. Whereas cbl C cells are completely deficient in the binding of [(57)Co]cobalamin to either enzyme, fibroblasts which bear the phenotypically similar but genetically distinct cbl D mutation retain some binding activity, and accordingly, have higher holomethyltransferase and holomutase activities than do cbl C cells. The defect in [(57)Co]-cobalamin binding exhibited by both cbl C and cbl D fibroblasts is almost certainly not a result of mutations which affect the methyltransferase or mutase apoenzymes, since the electrophoretic mobilities and the affinities of these enzymes for their respective cobalamin coenzymes are indistinguishable from those in control cell extracts. These results suggest that both the cbl C and cbl D mutations affect some enzymatic step(s) which converts newly taken up cobalamin to a form capable of being bound by the two cobalamin-dependent enzymes.

Cobalamin binding and cobalamin-dependent enzyme activity in normal and mutant human fibroblasts. We have studied the intracellular binding of radioactive cobalamin by normal cultured human fibroblasts grown in medium containing [(57)Co]-cobalamin. We have also assessed the significance of defects in this binding activity exhibited by two classes of human mutants (cbl C and cbl D) each characterized by pleiotropic deficiencies in the accumulation and retention of cobalamin, in the synthesis of cobalamin coenzymes, and accordingly, in the holoenzyme activities of both cobalamin-dependent enzymes, 5-methyltetrahydrofolate:homocysteine methyltransferase and methylmalonyl-CoA mutase. Based on the coincidence of [(57)Co]cobalamin binding and cobalamin-dependent enzyme activities after Sephadex G-150 chromatography and polyacrylamide gel electrophoresis, we conclude that, as in rat liver, the intracellular binding of labeled cobalamin by normal fibroblasts reflects the attachment of the vitamin to the cobalamin-dependent methyltransferase and mutase. Whereas cbl C cells are completely deficient in the binding of [(57)Co]cobalamin to either enzyme, fibroblasts which bear the phenotypically similar but genetically distinct cbl D mutation retain some binding activity, and accordingly, have higher holomethyltransferase and holomutase activities than do cbl C cells. The defect in [(57)Co]-cobalamin binding exhibited by both cbl C and cbl D fibroblasts is almost certainly not a result of mutations which affect the methyltransferase or mutase apoenzymes, since the electrophoretic mobilities and the affinities of these enzymes for their respective cobalamin coenzymes are indistinguishable from those in control cell extracts. These results suggest that both the cbl C and cbl D mutations affect some enzymatic step(s) which converts newly taken up cobalamin to a form capable of being bound by the two cobalamin-dependent enzymes.

PMID:30781

A new anticoagulant medication in cardiac valve replacement.

1. In the mitral valve replacement with Starr-Edwards prosthetic ball valve, the major thromboembolism occurred in 20% of the patients with the silastic ball valve series compared with 6% in those with a metal ball valve series. 2. The anticoagulant effect of Warfarin became stable and the occurrence of thromboembolism was reduced by the addition of Bucolome.

A new anticoagulant medication in cardiac valve replacement. 1. In the mitral valve replacement with Starr-Edwards prosthetic ball valve, the major thromboembolism occurred in 20% of the patients with the silastic ball valve series compared with 6% in those with a metal ball valve series. 2. The anticoagulant effect of Warfarin became stable and the occurrence of thromboembolism was reduced by the addition of Bucolome.

PMID:30787

The influence of fluoride on apatite formation from unstable supersaturated solutions at pH 7.4.

The present study was undertaken to examine the effect of fluoride on the formation of apatite in aqeous calcium phosphate suspensions prepared by spontaneous precipitation at pH 7.4. The most notable finding was that fluoride greatly curtailed or eliminated the appearance of octacalcium phosphate-like precursor phases in these preparations.

The influence of fluoride on apatite formation from unstable supersaturated solutions at pH 7.4. The present study was undertaken to examine the effect of fluoride on the formation of apatite in aqeous calcium phosphate suspensions prepared by spontaneous precipitation at pH 7.4. The most notable finding was that fluoride greatly curtailed or eliminated the appearance of octacalcium phosphate-like precursor phases in these preparations.

PMID:30799

Acid lipase: a histochemical and biochemical study using triton X100-naphtyl palmitate micelles.

Hydrolsis of a-naphtyl palmitate dispersed with the detergent Triton X-100 at acid pH was studied by a histochemical diazocoupling technique in both fixed sections and cultures of primate tissues as well as by a biochemical assay employing the same chromogenic substrate. Evidence for the exclusive hydrolysis of this artificial fatty acid ester substrate by acid lipases was gathered from (1) comparison of isoelectric focusing zymograms developed with different substrates, (2) kinetic analysis of enzyme activity in the presence or absence of inhibitors, including a natural substrate of acid lipase, trioleylglycerol, (3) specific localization of marked enzyme activity in certain tissues, and (4) absence of detectable enzyme activity in a case of human acid lipase deficiency (Wolman's disease). Histochemically, acid lipase activity was most readily detected in cells active in the uptake and processing of neutral lipids, i.e., the phagocytes of the reticuloendothelial system, the adrenal cortex and the lipid-storing cells in the athero-sclerotic plaques of arteries.

Acid lipase: a histochemical and biochemical study using triton X100-naphtyl palmitate micelles. Hydrolsis of a-naphtyl palmitate dispersed with the detergent Triton X-100 at acid pH was studied by a histochemical diazocoupling technique in both fixed sections and cultures of primate tissues as well as by a biochemical assay employing the same chromogenic substrate. Evidence for the exclusive hydrolysis of this artificial fatty acid ester substrate by acid lipases was gathered from (1) comparison of isoelectric focusing zymograms developed with different substrates, (2) kinetic analysis of enzyme activity in the presence or absence of inhibitors, including a natural substrate of acid lipase, trioleylglycerol, (3) specific localization of marked enzyme activity in certain tissues, and (4) absence of detectable enzyme activity in a case of human acid lipase deficiency (Wolman's disease). Histochemically, acid lipase activity was most readily detected in cells active in the uptake and processing of neutral lipids, i.e., the phagocytes of the reticuloendothelial system, the adrenal cortex and the lipid-storing cells in the athero-sclerotic plaques of arteries.

PMID:30800

On testing the activity of proteases from human polymorphonuclear neutrophils on blood smears.

A cytochemical method is presented for the demonstration of proteases in human polymorphonuclear (PMN) neutrophils on fixed blood smears. This new technique is based on solubilization of proteases from PMN neutrophils by incubation with 0.25 M NaCl in borate buffer at pH 8.5 which leads to degradation of erythrocytes and plasma in a disclike zone (halo) around centrally situated PMN neutrophils, an effect that is visualized by staining smears using a modified colloidal iron reaction. Halo formation is inhibited by trypsin inhibitors of soya-bean as well as of chicken egg white mucoid and by phenylmethyl-sulfonylfluoride.

On testing the activity of proteases from human polymorphonuclear neutrophils on blood smears. A cytochemical method is presented for the demonstration of proteases in human polymorphonuclear (PMN) neutrophils on fixed blood smears. This new technique is based on solubilization of proteases from PMN neutrophils by incubation with 0.25 M NaCl in borate buffer at pH 8.5 which leads to degradation of erythrocytes and plasma in a disclike zone (halo) around centrally situated PMN neutrophils, an effect that is visualized by staining smears using a modified colloidal iron reaction. Halo formation is inhibited by trypsin inhibitors of soya-bean as well as of chicken egg white mucoid and by phenylmethyl-sulfonylfluoride.

PMID:30802

The beta-adrenergic receptor of newborn mouse skin.

Binding of the potent beta-adrenergic antagonist [125I]iodohydroxybenzylpindolol ([125I]IHYP) to particulate preparations from newborn mouse skin was characterized. A number of criteria were used to establish that binding occurred to specific, high affinity beta-adrenergic receptors in the skin preparations. Thus specific binding (that displaced by 10 micrometer concentrations of the beta-adrenergic antagonist (-)propranolol) reached equilibrium in 15--20 min, was saturable (ligand concentration for half-maximal saturation, 0.25 nM) and freely reversible. Stereoselectivity of binding was demonstrated by the observation that displacement of [125I]IHYP by (-)propranolol occurred at concentrations at least 100 times lower than with (+)isoproterenol. Displacement was also observed with the beta-adrenergic agonists (-)isoproterenol, (-)epinephrine and (-)norepinephrine, but not with the alpha-adrenergic antagonist phentolamine.

The beta-adrenergic receptor of newborn mouse skin. Binding of the potent beta-adrenergic antagonist [125I]iodohydroxybenzylpindolol ([125I]IHYP) to particulate preparations from newborn mouse skin was characterized. A number of criteria were used to establish that binding occurred to specific, high affinity beta-adrenergic receptors in the skin preparations. Thus specific binding (that displaced by 10 micrometer concentrations of the beta-adrenergic antagonist (-)propranolol) reached equilibrium in 15--20 min, was saturable (ligand concentration for half-maximal saturation, 0.25 nM) and freely reversible. Stereoselectivity of binding was demonstrated by the observation that displacement of [125I]IHYP by (-)propranolol occurred at concentrations at least 100 times lower than with (+)isoproterenol. Displacement was also observed with the beta-adrenergic agonists (-)isoproterenol, (-)epinephrine and (-)norepinephrine, but not with the alpha-adrenergic antagonist phentolamine.

PMID:30803

Modification of otitis media following vaccination with the capsular polysaccharide of Streptococcus pneumoniae in chinchillas.

An animal model was used to determine whether vaccination with the capsular polysaccharide of Streptococcus pneumoniae could alter the development of experimental otitis media induced by the same type of S. pneumoniae as the vaccine. Following vaccination with the capsular polysaccharide of S. pneumoniae type 7, 36(63%) of 57 chinchillas seroconverted with at least a 100% increase in concentration of antibody in serum which remained elevated for at least six weeks. The middle ears of 23 chinchillas that were vaccinated and seroconverted, 13 that were vaccinated and did not seroconvert, and 47 that were not vaccinated were inoculated with S. pneumoniae type 7. Vaccinated animals that seroconverted developed otitis media as readily as nonseroconverting and unvaccinated animals but had fewer pneumococci in their middle ears, a lower incidence of bacteremia, and lower mortality rates during the first week after inoculation of bacteria. Animals that did not seroconvert showed no evidence of modification of their middle ear infections. These results indicate that type 7 pneumococcal capsular polysaccharide vaccine is antigenic for the chinchilla and modifies experimental otitis media due to type 7 S. pneumoniae.

Modification of otitis media following vaccination with the capsular polysaccharide of Streptococcus pneumoniae in chinchillas. An animal model was used to determine whether vaccination with the capsular polysaccharide of Streptococcus pneumoniae could alter the development of experimental otitis media induced by the same type of S. pneumoniae as the vaccine. Following vaccination with the capsular polysaccharide of S. pneumoniae type 7, 36(63%) of 57 chinchillas seroconverted with at least a 100% increase in concentration of antibody in serum which remained elevated for at least six weeks. The middle ears of 23 chinchillas that were vaccinated and seroconverted, 13 that were vaccinated and did not seroconvert, and 47 that were not vaccinated were inoculated with S. pneumoniae type 7. Vaccinated animals that seroconverted developed otitis media as readily as nonseroconverting and unvaccinated animals but had fewer pneumococci in their middle ears, a lower incidence of bacteremia, and lower mortality rates during the first week after inoculation of bacteria. Animals that did not seroconvert showed no evidence of modification of their middle ear infections. These results indicate that type 7 pneumococcal capsular polysaccharide vaccine is antigenic for the chinchilla and modifies experimental otitis media due to type 7 S. pneumoniae.

PMID:30804

Correction of metabolic acidosis by the kidney during isometric expansion of extracellular fluid volume.

In dogs with chronic hypochloremic metabolic alkalosis associated with ECFV contraction, plasma [HCO-3] ([HCO-3]p) normalizes during expansion of ECFV with a solution containing Cl- and HCO-3 in concentrations duplicating those in the plasma before expansion (isometric expansion). The kidney selectively rejects administered HCO-3 and retains Cl-. If this preferential Cl- less than HCO-3 reabsorptive selectivity were a characteristic renal response to ECFV expansion, isometric expansion during hyperchloremic acidosis would exacerbate the acid-base disturbance rather than correct it as it does in alkalosis. We examined the effect of isometric expansion in dogs with chronic hyperchloremic metabolic acidosis induced by HCl feeding or mineralocorticoid hormone deficiency. During expansion, as the expected decrease occurred in the fractional reabsorption of Na+, a lesser decrease occurred in fractional reabsorption of HCO-3, whereas a greater decrease occurred in fractional reabsorption of Cl-. The kidney selectively retained administered HCO3 and rejected Cl-. [HCO-3]p normalized. The shift to bicarbonate-selective from chloride-selective anion reabsorption during ECFV expansion in metabolic acidosis vs. metabolic alkalosis indicates that in response to ECFV expansion- the kidney selectively alters the ratio of bicarbonate to chloride concentration in the tubular reabsorbate in the direction that tends to normalize plasma acid-base composition, irrespective of the direction of deviation of the initial plasma bicarbonate concentration. The signal that initiates the shift in anion reabsorptive selectivity remains to be identified.

Correction of metabolic acidosis by the kidney during isometric expansion of extracellular fluid volume. In dogs with chronic hypochloremic metabolic alkalosis associated with ECFV contraction, plasma [HCO-3] ([HCO-3]p) normalizes during expansion of ECFV with a solution containing Cl- and HCO-3 in concentrations duplicating those in the plasma before expansion (isometric expansion). The kidney selectively rejects administered HCO-3 and retains Cl-. If this preferential Cl- less than HCO-3 reabsorptive selectivity were a characteristic renal response to ECFV expansion, isometric expansion during hyperchloremic acidosis would exacerbate the acid-base disturbance rather than correct it as it does in alkalosis. We examined the effect of isometric expansion in dogs with chronic hyperchloremic metabolic acidosis induced by HCl feeding or mineralocorticoid hormone deficiency. During expansion, as the expected decrease occurred in the fractional reabsorption of Na+, a lesser decrease occurred in fractional reabsorption of HCO-3, whereas a greater decrease occurred in fractional reabsorption of Cl-. The kidney selectively retained administered HCO3 and rejected Cl-. [HCO-3]p normalized. The shift to bicarbonate-selective from chloride-selective anion reabsorption during ECFV expansion in metabolic acidosis vs. metabolic alkalosis indicates that in response to ECFV expansion- the kidney selectively alters the ratio of bicarbonate to chloride concentration in the tubular reabsorbate in the direction that tends to normalize plasma acid-base composition, irrespective of the direction of deviation of the initial plasma bicarbonate concentration. The signal that initiates the shift in anion reabsorptive selectivity remains to be identified.

PMID:30806

Analysis of the iron-binding sites of transferrin by isoelectric focussing.

1. Human transferrin was labelled with ferric nitrilotriacetate (FeNTA) at one of its two metal binding sites by variation of the pH. 2. Four transferrin forms, transferrin, transferrin(Fe) (A-site), transferrin(Fe) (B-site) and transferrin(2Fe) could be separated on flat bed gels by isoelectric focussing. 3. Incubation time, temperature and medium play an important role in the specificity of the binding of Fe. In NTA-pH-buffer, at 0.5 Fe-saturation, the A-site was preferentially labelled at pH 7--8, the B-site at a pH 8--9. 4. Under physiological conditions iron from the B-site has the tendency to move to the A-site.

Analysis of the iron-binding sites of transferrin by isoelectric focussing. 1. Human transferrin was labelled with ferric nitrilotriacetate (FeNTA) at one of its two metal binding sites by variation of the pH. 2. Four transferrin forms, transferrin, transferrin(Fe) (A-site), transferrin(Fe) (B-site) and transferrin(2Fe) could be separated on flat bed gels by isoelectric focussing. 3. Incubation time, temperature and medium play an important role in the specificity of the binding of Fe. In NTA-pH-buffer, at 0.5 Fe-saturation, the A-site was preferentially labelled at pH 7--8, the B-site at a pH 8--9. 4. Under physiological conditions iron from the B-site has the tendency to move to the A-site.

PMID:30807

[Induction of tyrosine aminotransferase (EC 2.5.1.5) by nicotinamide in rat liver (author's transl)].

In intact rats nicotinamide induces an increase of tyrosine aminotransferase depending on the dose of nicotinamide. In adrenalectomized rats an increase of tyrosine aminotransferase activity is only found up to a dose of 250 mg/kg nicotinamide. The combination of nicotinamide with L-methionine and/or cortisone acetate does not cause a significant increase of the enzyme activity, which, however, can be seen in the presence of L-tyrosine.

[Induction of tyrosine aminotransferase (EC 2.5.1.5) by nicotinamide in rat liver (author's transl)]. In intact rats nicotinamide induces an increase of tyrosine aminotransferase depending on the dose of nicotinamide. In adrenalectomized rats an increase of tyrosine aminotransferase activity is only found up to a dose of 250 mg/kg nicotinamide. The combination of nicotinamide with L-methionine and/or cortisone acetate does not cause a significant increase of the enzyme activity, which, however, can be seen in the presence of L-tyrosine.

PMID:30809

Microbiology of recurrent and chronic otitis media with effusion.

A study was conducted of 274 children who had recurrent acute or chronic otitis media with effusion. Forty-five percent of the ears with effusion were found to contain bacteria, and 11% contained bacteria that were "probable pathogens" (S. pneumoniae, H. influenzae, and S. pyogenes). Bacteria were also found in 40% of the ears without effusions. The type of organism found did not vary with the age of the patient studied or the season of the year. The significance of these bacteria in the etiology of recurrent acute or chronic otitis media with effusion remains to be demonstrated.

Microbiology of recurrent and chronic otitis media with effusion. A study was conducted of 274 children who had recurrent acute or chronic otitis media with effusion. Forty-five percent of the ears with effusion were found to contain bacteria, and 11% contained bacteria that were "probable pathogens" (S. pneumoniae, H. influenzae, and S. pyogenes). Bacteria were also found in 40% of the ears without effusions. The type of organism found did not vary with the age of the patient studied or the season of the year. The significance of these bacteria in the etiology of recurrent acute or chronic otitis media with effusion remains to be demonstrated.

PMID:30810

Angiography of the testicular artery as a diagnostic aid in boys with nonpalpable testis.

Selective angiography of the testicular artery was performed in 12 boys (age 3-14 yr) with nonpalpable testis. The angiographic, operative, and microscopic findings are described. True aplasia was diagnosed in seven patients. In three patients previously operated upon, the second exploration was facilitated by angiography. This method might be a valuable diagnostic aid in selected cases previously operated for gonadal disorders or inadequately explored for cryptorchism in order to avoid more extensive surgical exploration.

Angiography of the testicular artery as a diagnostic aid in boys with nonpalpable testis. Selective angiography of the testicular artery was performed in 12 boys (age 3-14 yr) with nonpalpable testis. The angiographic, operative, and microscopic findings are described. True aplasia was diagnosed in seven patients. In three patients previously operated upon, the second exploration was facilitated by angiography. This method might be a valuable diagnostic aid in selected cases previously operated for gonadal disorders or inadequately explored for cryptorchism in order to avoid more extensive surgical exploration.

PMID:30812

Time-dependent deformation of some direct compression excipients.

Three techniques were used to compare the time-dependent deformation of microfine cellulose (Elcema G250), anhydrous lactose, dicalcium phosphate dihydrate (Emcompress), modified starch (Sta-Rx 1500) and sodium chloride. (1) In stress-relaxation experiments using a reciprocating tablet machine, none of the materials behaved as a Maxwell body in contrast to recent published work (David & Augsburger, 1977). Possible reasons for this disagreement are discussed. (2) Heckel plots showed that increasing the time for which a material was under compression (contact times of 0.17 and 10 s) had no effect on dicalcium phosphate compacts but increased the consolidation of other materials in the rank order sodium chloride less than lactose less than cellulose less than starch. (3) Deformation tests on preformed compacts were carried out in diametral compression by loading compacts to 75% of their breaking force at four different strain rates between 0.05 and 6.5 mm min-1. The deformation of Sta-Rx compacts was time-dependent. Sodium chloride compacts exhibited brittle behaviour in the diametral compression test and in the 10 s contact time experiment. This was apparently due to work-hardening, following the extensive plastic deformation of crystals during compaction as indicated by the stress relaxation results.

Time-dependent deformation of some direct compression excipients. Three techniques were used to compare the time-dependent deformation of microfine cellulose (Elcema G250), anhydrous lactose, dicalcium phosphate dihydrate (Emcompress), modified starch (Sta-Rx 1500) and sodium chloride. (1) In stress-relaxation experiments using a reciprocating tablet machine, none of the materials behaved as a Maxwell body in contrast to recent published work (David & Augsburger, 1977). Possible reasons for this disagreement are discussed. (2) Heckel plots showed that increasing the time for which a material was under compression (contact times of 0.17 and 10 s) had no effect on dicalcium phosphate compacts but increased the consolidation of other materials in the rank order sodium chloride less than lactose less than cellulose less than starch. (3) Deformation tests on preformed compacts were carried out in diametral compression by loading compacts to 75% of their breaking force at four different strain rates between 0.05 and 6.5 mm min-1. The deformation of Sta-Rx compacts was time-dependent. Sodium chloride compacts exhibited brittle behaviour in the diametral compression test and in the 10 s contact time experiment. This was apparently due to work-hardening, following the extensive plastic deformation of crystals during compaction as indicated by the stress relaxation results.

PMID:30813

Phospholipase inactivation induced by an amino-piperazine derivative: a study at the lipid-water interface.

1-Amino-4-octylpiperazine, AP 22, an antiviral agent causes lipid accumulation in nervous tissue cultures. A physicochemical membrane model was used to demonstrate the formation of a lipid-AP 22 complex hindering phospholipase A2 action. A well defined amphiphilic balance seems essential to explain the mode of action of the drug. The hydrophilic group prevents enzyme-substrate complex formation whereas the hydrophobic group allows the penetration in the lipid layer and determines the stability of the drug-lipid complex. This stability of the drug-lipid association has a direct influence on phospholipase A2 activity but does not affect phospholipase C activity. No inactivation of phospholipase A2 due to a drug-enzyme interaction could be detected.

Phospholipase inactivation induced by an amino-piperazine derivative: a study at the lipid-water interface. 1-Amino-4-octylpiperazine, AP 22, an antiviral agent causes lipid accumulation in nervous tissue cultures. A physicochemical membrane model was used to demonstrate the formation of a lipid-AP 22 complex hindering phospholipase A2 action. A well defined amphiphilic balance seems essential to explain the mode of action of the drug. The hydrophilic group prevents enzyme-substrate complex formation whereas the hydrophobic group allows the penetration in the lipid layer and determines the stability of the drug-lipid complex. This stability of the drug-lipid association has a direct influence on phospholipase A2 activity but does not affect phospholipase C activity. No inactivation of phospholipase A2 due to a drug-enzyme interaction could be detected.

PMID:30815

Baclofen (beta-p-chlorophenyl-gamma-aminobutyric acid) enhances [3H]gamma-aminobutyric acid (3H-GABA) release from rat globus pallidus in vitro.

The rat globus pallidus has been investigated as a possible model in which to study pre-synaptic GABA mechanisms in vitro. (+/-)-Baclofen (300 micrometer-1 mM) significantly enhanced the release of radioactivity from superfused slices of rat globus pallidus prelabelled with 3H-GABA in vitro. This releasing action was specific to the (+)-isomer of baclofen: neither the (-)-isomer nor another neuronal depressant dl-alpha-epsilon-diaminopimelic acid had any significant effect. The releasing effect of baclofen appeared unrelated to the phenethylamine moiety of its structure as neither beta-phenethylamine nor dopamine evoked release of 3H-GABA from pallidal slices. Baclofen increased the efflux of radioactivity from pallidal slices prelabelled with either [3H]-beta-alanine or [3H]diaminobutyric acid in vitro. The use of specific glial and neuronal GABA uptake blocking compounds (beta-alanine and (+/-)-cis-1,3-amino-cyclohexanecarboxylic acid) did not permit resolution of the elements from which baclofen was evoking [3H]GABA release. Baclofen also inhibited uptake of [3H]GABA into pallidal slices with an IC50 value of 6 x 10(-4) m. The GABA-like properties of baclofen may be related to the (+)-isomer while non-specific neuronal depressant actions are an effect of the (-)-isomer. The potential of the (+)-isomer as an antipsychotic agent while (-)-baclofen remains the effective antispastic drug free from unwanted side-effects, is discussed.

Baclofen (beta-p-chlorophenyl-gamma-aminobutyric acid) enhances [3H]gamma-aminobutyric acid (3H-GABA) release from rat globus pallidus in vitro. The rat globus pallidus has been investigated as a possible model in which to study pre-synaptic GABA mechanisms in vitro. (+/-)-Baclofen (300 micrometer-1 mM) significantly enhanced the release of radioactivity from superfused slices of rat globus pallidus prelabelled with 3H-GABA in vitro. This releasing action was specific to the (+)-isomer of baclofen: neither the (-)-isomer nor another neuronal depressant dl-alpha-epsilon-diaminopimelic acid had any significant effect. The releasing effect of baclofen appeared unrelated to the phenethylamine moiety of its structure as neither beta-phenethylamine nor dopamine evoked release of 3H-GABA from pallidal slices. Baclofen increased the efflux of radioactivity from pallidal slices prelabelled with either [3H]-beta-alanine or [3H]diaminobutyric acid in vitro. The use of specific glial and neuronal GABA uptake blocking compounds (beta-alanine and (+/-)-cis-1,3-amino-cyclohexanecarboxylic acid) did not permit resolution of the elements from which baclofen was evoking [3H]GABA release. Baclofen also inhibited uptake of [3H]GABA into pallidal slices with an IC50 value of 6 x 10(-4) m. The GABA-like properties of baclofen may be related to the (+)-isomer while non-specific neuronal depressant actions are an effect of the (-)-isomer. The potential of the (+)-isomer as an antipsychotic agent while (-)-baclofen remains the effective antispastic drug free from unwanted side-effects, is discussed.

PMID:30816

The indirect sympathomimetic activity of etilefrine--a comparison with tyramine and ephedrine using [3H] noradrenaline.

The indirect sympathomimetic activity of etilefrine has been examined using the ventral caudal artery of the rat. This vessel has a rich sympathetic innervation and lends itself to studies on [3H]noradrenaline efflux from these sites. Etilefrine possessed significant indirect activity on the artery and this action, although less than that of tyramine, was equivalent to that caused by ephedrine. Pretreatment of the vessels with a mixture of iproniazid, doca, cocaine and UO521 (3',4'-dihydroxy-2-methyl propiophenone) significantly enhanced[3H]-noradrenaline efflux from the artery.

The indirect sympathomimetic activity of etilefrine--a comparison with tyramine and ephedrine using [3H] noradrenaline. The indirect sympathomimetic activity of etilefrine has been examined using the ventral caudal artery of the rat. This vessel has a rich sympathetic innervation and lends itself to studies on [3H]noradrenaline efflux from these sites. Etilefrine possessed significant indirect activity on the artery and this action, although less than that of tyramine, was equivalent to that caused by ephedrine. Pretreatment of the vessels with a mixture of iproniazid, doca, cocaine and UO521 (3',4'-dihydroxy-2-methyl propiophenone) significantly enhanced[3H]-noradrenaline efflux from the artery.

PMID:30817

Differences in responsiveness to adipokinetic agents between white epididymal and brown interscapula adipose tissue from rats.

Lipolytic activity was studied in brown and white adipose tissue of rats in vitro. 5-Hydroxy-tryptamine (5-HT), phenylephrine, noradrenaline, adrenaline and isoprenaline were used as adipokinetic agents. All stimulated lipolysis in brown adipose tissue, but 5-HT and phenyl-ephrine did not in white adipose tissue. A beta-blocking drug, propranolol, inhibited the stimulatory effect of the agents in both adipose tissues. However, an alpha-blocking drug, phentolamine, further increased the lipolysis induced by noradrenaline or adrenaline in brown adipose tissue and inhibited the effect of isoprenaline. In white adipose tissue, its action was to marginally decrease the effect of adrenaline and noradrenaline. Increase in the pH of the incubation medium stimulated FFA and glycerol release in brown adipose tissue, but not in the epididymal adipose tissue. This effect of pH on lipolysis was further enhanced by phentolamine and decreased by propranolol. Increase of lipolysis with pH was not seen with brown fat tissue from the reserpine-treated rats. These results show that brown adipose tissue of the rat has an alpha-receptor with inhibitory effects on lipolysis that is affected by alpha- or mixed-type adrenergic agonists, noradrenaline and adrenaline.

Differences in responsiveness to adipokinetic agents between white epididymal and brown interscapula adipose tissue from rats. Lipolytic activity was studied in brown and white adipose tissue of rats in vitro. 5-Hydroxy-tryptamine (5-HT), phenylephrine, noradrenaline, adrenaline and isoprenaline were used as adipokinetic agents. All stimulated lipolysis in brown adipose tissue, but 5-HT and phenyl-ephrine did not in white adipose tissue. A beta-blocking drug, propranolol, inhibited the stimulatory effect of the agents in both adipose tissues. However, an alpha-blocking drug, phentolamine, further increased the lipolysis induced by noradrenaline or adrenaline in brown adipose tissue and inhibited the effect of isoprenaline. In white adipose tissue, its action was to marginally decrease the effect of adrenaline and noradrenaline. Increase in the pH of the incubation medium stimulated FFA and glycerol release in brown adipose tissue, but not in the epididymal adipose tissue. This effect of pH on lipolysis was further enhanced by phentolamine and decreased by propranolol. Increase of lipolysis with pH was not seen with brown fat tissue from the reserpine-treated rats. These results show that brown adipose tissue of the rat has an alpha-receptor with inhibitory effects on lipolysis that is affected by alpha- or mixed-type adrenergic agonists, noradrenaline and adrenaline.

PMID:30818

The absorption of aliphatic carbamates from the rat colon.

The colonic absorptio n of a series of aliphatic carbamates has been studied using an in situ preparation in the rat. The absorption process appeared to be passive and no metabolism by the colon membrane was detected. A linear correlation between the logarithms of the absorption rate constants and apparent partition coefficients was found. The absorption rates were not affected by concurrent water flux.

The absorption of aliphatic carbamates from the rat colon. The colonic absorptio n of a series of aliphatic carbamates has been studied using an in situ preparation in the rat. The absorption process appeared to be passive and no metabolism by the colon membrane was detected. A linear correlation between the logarithms of the absorption rate constants and apparent partition coefficients was found. The absorption rates were not affected by concurrent water flux.

PMID:30835

Mechanism of fluorometric analysis of tetracycline involving metal complexation.

Tetracycline complexation with calcium and organic ligands was studied using fluorescence, circular dichroism, and solvent extraction methods. The results were used to interpret the mechanism of the commonly used fluorometric methods for the analysis of tetracycline in biological fluids. Tetracycline formed ternary calcium complexes with barbital sodium and L-tryptophan in alkaline solutions. The circular dichroism studies indicate that the calcium ion in these complexes is bound to the C-4 dimethylamino and the C-12a hydroxyl groups of tetracycline. These ternary complexes are strongly fluorescent and can be extracted easily into 1-butanol or ethyl acetate. Based on the characteristics of the ternary complexes and of the tetracycline degradation products, it is concluded that only the active form of tetracycline can be complexed and extracted for fluorescence analysis.

Mechanism of fluorometric analysis of tetracycline involving metal complexation. Tetracycline complexation with calcium and organic ligands was studied using fluorescence, circular dichroism, and solvent extraction methods. The results were used to interpret the mechanism of the commonly used fluorometric methods for the analysis of tetracycline in biological fluids. Tetracycline formed ternary calcium complexes with barbital sodium and L-tryptophan in alkaline solutions. The circular dichroism studies indicate that the calcium ion in these complexes is bound to the C-4 dimethylamino and the C-12a hydroxyl groups of tetracycline. These ternary complexes are strongly fluorescent and can be extracted easily into 1-butanol or ethyl acetate. Based on the characteristics of the ternary complexes and of the tetracycline degradation products, it is concluded that only the active form of tetracycline can be complexed and extracted for fluorescence analysis.

PMID:30836

Degradative behavior of a new bronchodilator, carbuterol, in aqueous solution.

The degradation kinetics of carbuterol in aqueous solution were investigated at 85 degrees and constant ionic strength over the pH 0.25--13.3 range under anaerobic conditions. The results demonstrated a complex kinetic pattern involving specific acid and specific base catalyses at the pH extremes. Degradation resulted primarily from intramolecular catalysis and indicated that both the protonated and unprotonated phenolic groups participated in the reaction. High-pressure liquid chromatography was used to isolate carbuterol and its degradation product. Mass spectrometric examination showed that the degradation product was a cyclized derivative formed by intramolecular attack of the phenoxy group on the ureido carbonyl with ammonia expulsion. The apparent activation energy for carbuterol at pH 4.0 and 10.0 was 22.3 and 11.7 kcal/mole, respectively. The agreement between the calculated theoretical pH--rate profile and the experimental points supports the hypothesis presented concerning the reactions involved in carbuterol degradation.

Degradative behavior of a new bronchodilator, carbuterol, in aqueous solution. The degradation kinetics of carbuterol in aqueous solution were investigated at 85 degrees and constant ionic strength over the pH 0.25--13.3 range under anaerobic conditions. The results demonstrated a complex kinetic pattern involving specific acid and specific base catalyses at the pH extremes. Degradation resulted primarily from intramolecular catalysis and indicated that both the protonated and unprotonated phenolic groups participated in the reaction. High-pressure liquid chromatography was used to isolate carbuterol and its degradation product. Mass spectrometric examination showed that the degradation product was a cyclized derivative formed by intramolecular attack of the phenoxy group on the ureido carbonyl with ammonia expulsion. The apparent activation energy for carbuterol at pH 4.0 and 10.0 was 22.3 and 11.7 kcal/mole, respectively. The agreement between the calculated theoretical pH--rate profile and the experimental points supports the hypothesis presented concerning the reactions involved in carbuterol degradation.

PMID:30837

Mechanism of hydrolysis of halogenated nitrosoureas.

The hydrolysis kinetics of halogenated nitrosoureas were investigated using chlorozotocin as a model. Evidence is presented to show that the hydrolytic reaction of halogenated nitrosoureas between pH 3 and 8 is a summation of spontaneous water and hydroxide-ion-catalyzed reactions; the later reaction is the sum of two parallel reactions. The relative contribuiton of each reaction changes with pH and results in different product distributions. Dianionic phosphate (HPO42-) increased the amount of free chloride-ion production without significantly altering the hydrolysis rate. A mechanism is proposed to explain this behavior. The role of hydrolytic decomposition products produced at physiological pH on the biological activity of nitrosoureas is discussed.

Mechanism of hydrolysis of halogenated nitrosoureas. The hydrolysis kinetics of halogenated nitrosoureas were investigated using chlorozotocin as a model. Evidence is presented to show that the hydrolytic reaction of halogenated nitrosoureas between pH 3 and 8 is a summation of spontaneous water and hydroxide-ion-catalyzed reactions; the later reaction is the sum of two parallel reactions. The relative contribuiton of each reaction changes with pH and results in different product distributions. Dianionic phosphate (HPO42-) increased the amount of free chloride-ion production without significantly altering the hydrolysis rate. A mechanism is proposed to explain this behavior. The role of hydrolytic decomposition products produced at physiological pH on the biological activity of nitrosoureas is discussed.

PMID:30838

Potential antitumor agents via inhibitors of L-asparagine synthetase: substituted sulfonamides and sulfonyl hydrazides related to glutamine.

A series of 4-(substituted aminosulfonyl)- and 4-(substituted hydrazinosulfonyl)-2-aminobutanoic acids, compounds structurally related to glutamine, was synthesized as potential inhibitors of L-asparagine synthetase and subjected to screening as antitumor agents. Target amino acids were obtained by condensation of a blocked reactive sulfonyl chloride with the appropriate amine or hydrazide, followed by deblocking with hydrogen--palladium or liquid hydrogen fluoride--anisole. Neither the target compounds nor their protected precursors inhibited the enzyme from L5178Y/AR or prolonged the life of mice with P-388 lymphocytic leukemia. However, DL-4,4'-dithiobis[2-(benzyloxycarbonylamino)butanoic acid], an intermediate in the synthesis of the target amino acids, exhibited 90% inhibition of L-asparagine synthetase at 10 mM.

Potential antitumor agents via inhibitors of L-asparagine synthetase: substituted sulfonamides and sulfonyl hydrazides related to glutamine. A series of 4-(substituted aminosulfonyl)- and 4-(substituted hydrazinosulfonyl)-2-aminobutanoic acids, compounds structurally related to glutamine, was synthesized as potential inhibitors of L-asparagine synthetase and subjected to screening as antitumor agents. Target amino acids were obtained by condensation of a blocked reactive sulfonyl chloride with the appropriate amine or hydrazide, followed by deblocking with hydrogen--palladium or liquid hydrogen fluoride--anisole. Neither the target compounds nor their protected precursors inhibited the enzyme from L5178Y/AR or prolonged the life of mice with P-388 lymphocytic leukemia. However, DL-4,4'-dithiobis[2-(benzyloxycarbonylamino)butanoic acid], an intermediate in the synthesis of the target amino acids, exhibited 90% inhibition of L-asparagine synthetase at 10 mM.

PMID:30839

Hemolytic properties of synthetic glycosides.

Cholesteryl alpha-L-rhamnopyranoside, tigogenyl alpha-L-rhamnopyranoside, tigogenyl beta-D-fucopyranoside, smilagenyl beta-D-fucopyranoside, cholesteryl beta-maltoside, tigogenyl beta-maltoside, and smilagenyl beta-maltoside were synthesized and characterized. The rhamnosides and fucosides, as well as some other steroid monoglycosides, proved to be extremely insoluble in water. The concentration giving 50% hemolysis, H50, was of the same order of magnitude for all synthetic glycosides. Ghost cells collected from blood hemolyzed by smilagenyl maltoside and tigogenyl maltoside had appreciable amounts of absorbed aglycones. All results are in accordance with previous investigations on the mechanism of saponin and sapogenin hemolysis.

Hemolytic properties of synthetic glycosides. Cholesteryl alpha-L-rhamnopyranoside, tigogenyl alpha-L-rhamnopyranoside, tigogenyl beta-D-fucopyranoside, smilagenyl beta-D-fucopyranoside, cholesteryl beta-maltoside, tigogenyl beta-maltoside, and smilagenyl beta-maltoside were synthesized and characterized. The rhamnosides and fucosides, as well as some other steroid monoglycosides, proved to be extremely insoluble in water. The concentration giving 50% hemolysis, H50, was of the same order of magnitude for all synthetic glycosides. Ghost cells collected from blood hemolyzed by smilagenyl maltoside and tigogenyl maltoside had appreciable amounts of absorbed aglycones. All results are in accordance with previous investigations on the mechanism of saponin and sapogenin hemolysis.

PMID:30840

Intrinsic factor-mediated binding of cyanocobalamin to cholestyramine.

The intrinsic factor-mediated binding of cyanocobalamin to cholestyramine was studied in vitro under varying conditions of pH, added electrolyte, and bile salt. The intrinsic factor-cyanocobalamin complex was adsorbed strongly by the resin at pH 3 in the presence of neutral salt and low concentrations of glycocholic acid. An increase in glycocholic acid concentration as well as neutral pH decreased the observed binding, although significant amounts of cyanocobalamin-intrinsic factor complex remained bound after incubation at pH 6.8. Cyanocobalamin alone was not adsorbed by the resin.

Intrinsic factor-mediated binding of cyanocobalamin to cholestyramine. The intrinsic factor-mediated binding of cyanocobalamin to cholestyramine was studied in vitro under varying conditions of pH, added electrolyte, and bile salt. The intrinsic factor-cyanocobalamin complex was adsorbed strongly by the resin at pH 3 in the presence of neutral salt and low concentrations of glycocholic acid. An increase in glycocholic acid concentration as well as neutral pH decreased the observed binding, although significant amounts of cyanocobalamin-intrinsic factor complex remained bound after incubation at pH 6.8. Cyanocobalamin alone was not adsorbed by the resin.

PMID:30841

Antagonism by naloxone of narcotic-induced respiratory depression and analgesia.

Receptor mechanisms for narcotic-induced respiratory depression and analgesia were compared by apparent pA2 values of morphine-naloxone, levorphanol-naloxone and pentazocine-naloxone. The similarity of apparent pA2 values of the three compunds for respiratory depression suggests that morphine, levorphanol and pentazocine may interact with similar receptors to produce this effect. Significant differences between apparent pA2 values of pentazocine-naloxone and morphine-naloxone or levor-phanol-naloxone for analgesia suggest, as previously shown, that narcotic and narcotic-antagonist analgesics appear to interact with receptors in different manners. Significant differences between apparent pA2 values for respiratory depression and analgesia suggest that these two effects of the narcotic drugs are mediated by different receptor interactions.

Antagonism by naloxone of narcotic-induced respiratory depression and analgesia. Receptor mechanisms for narcotic-induced respiratory depression and analgesia were compared by apparent pA2 values of morphine-naloxone, levorphanol-naloxone and pentazocine-naloxone. The similarity of apparent pA2 values of the three compunds for respiratory depression suggests that morphine, levorphanol and pentazocine may interact with similar receptors to produce this effect. Significant differences between apparent pA2 values of pentazocine-naloxone and morphine-naloxone or levor-phanol-naloxone for analgesia suggest, as previously shown, that narcotic and narcotic-antagonist analgesics appear to interact with receptors in different manners. Significant differences between apparent pA2 values for respiratory depression and analgesia suggest that these two effects of the narcotic drugs are mediated by different receptor interactions.

PMID:30849

The effect of beta adrenergic receptor blockade on the renin response to respiratory acidosis.

The effect of beta adrenergic blockade on the increase in plasma renin activity produced by acute respiratory acidosis was studied in chloralose anesthetized dogs. Sixteen mongrel dogs were given 4%, 8% and 12% CO2 in room air, successively. Propranolol (2 mg/Kg) was given to 8 dogs prior to CO2 inhalation. The other 8 dogs served as the control group. The response of elevated plasma renin activity during 4% and 8% CO2 inhalation was not different between the control and propranolol groups. However, the increase of plasma renin activity in the control group was greater than that of the propranolol treated group during 12% CO2 inhalation. It is suggested that activation of beta adrenergic receptors is not the sole factor in renin control during acute respiratory acidosis, although these receptors do mediate a significant fraction of the renin response to CO2 inhalation.

The effect of beta adrenergic receptor blockade on the renin response to respiratory acidosis. The effect of beta adrenergic blockade on the increase in plasma renin activity produced by acute respiratory acidosis was studied in chloralose anesthetized dogs. Sixteen mongrel dogs were given 4%, 8% and 12% CO2 in room air, successively. Propranolol (2 mg/Kg) was given to 8 dogs prior to CO2 inhalation. The other 8 dogs served as the control group. The response of elevated plasma renin activity during 4% and 8% CO2 inhalation was not different between the control and propranolol groups. However, the increase of plasma renin activity in the control group was greater than that of the propranolol treated group during 12% CO2 inhalation. It is suggested that activation of beta adrenergic receptors is not the sole factor in renin control during acute respiratory acidosis, although these receptors do mediate a significant fraction of the renin response to CO2 inhalation.

PMID:30853

[Comparative characteristics of various anti-arrhythmia agents used under clinical conditions].

Comparative clinical and experimental study of the efficacy of the currently used anti-arrhythmic agents was conducted on 610 patients (828 cases) with various disorders of the cardiac rhythm. The modern classification of these agents is given. The indications and contra-indications for the prescription of the drugs, the optimum doses, and the routes of administration are discussed. Differentiated therapy in various disorders of the cardiac rhythm is recommended.

[Comparative characteristics of various anti-arrhythmia agents used under clinical conditions]. Comparative clinical and experimental study of the efficacy of the currently used anti-arrhythmic agents was conducted on 610 patients (828 cases) with various disorders of the cardiac rhythm. The modern classification of these agents is given. The indications and contra-indications for the prescription of the drugs, the optimum doses, and the routes of administration are discussed. Differentiated therapy in various disorders of the cardiac rhythm is recommended.

PMID:30855

[Serumconcentrations of non esterified fatty acids during operative stress and blockade of betaadrenergic receptors (author's transl)].

Every stress reaction leads to an increased, hormonelly induced mobilisation of fatty acids, the extent of which may be considered as a parameter of the aggression mechanism. In 15 patients with idiopathic trigeminal neuralgia, who were operated under neurolepthypalgesia, the problem of quantitative alterations of the concentration pattern of fatty acids was investigated during the operation. In contrast to some reports of the literature, the increase of the concentration of total fatty acids was due to corresponding increases of all individual fatty acids. By preoperative administration of the beta-adrenergic blocking agent Pindolol the increase of fatty acids was reduced without a qualitative shifting of individual fatty acids.

[Serumconcentrations of non esterified fatty acids during operative stress and blockade of betaadrenergic receptors (author's transl)]. Every stress reaction leads to an increased, hormonelly induced mobilisation of fatty acids, the extent of which may be considered as a parameter of the aggression mechanism. In 15 patients with idiopathic trigeminal neuralgia, who were operated under neurolepthypalgesia, the problem of quantitative alterations of the concentration pattern of fatty acids was investigated during the operation. In contrast to some reports of the literature, the increase of the concentration of total fatty acids was due to corresponding increases of all individual fatty acids. By preoperative administration of the beta-adrenergic blocking agent Pindolol the increase of fatty acids was reduced without a qualitative shifting of individual fatty acids.

PMID:30856

[The importance of changes in whole-body balance of sodium and noradrenaline in essential hypertension (author's transl)].

In 22 patients with essential hypertension plasma levels and urine excretions of sodium and noradrenaline were studied before, during and after long-term beta-blockade with pindolol. The relation between mean blood pressure and the quotient of sodium-/noradrenaline-excretion changed during treatment (placebo r=-0.34; pindolol r=+0.31). During placebo there existed a significant (p is less than 0.03) correlation between blood pressure and sodium-excretion which disappeared during beta-blockade. No correlation between blood pressure and noradrenaline was seen during placebo, whereas during beta-blockade a significant (p is less than 0.003) correlation was observed. In contrast to the placebo period there was a significant positive correlation between sodium- and noradrenaline-excretion during long-term treatment with pindolol. It is concluded that whole-body balance of sodium and noradrenaline is an important factor in essential hypertension.

[The importance of changes in whole-body balance of sodium and noradrenaline in essential hypertension (author's transl)]. In 22 patients with essential hypertension plasma levels and urine excretions of sodium and noradrenaline were studied before, during and after long-term beta-blockade with pindolol. The relation between mean blood pressure and the quotient of sodium-/noradrenaline-excretion changed during treatment (placebo r=-0.34; pindolol r=+0.31). During placebo there existed a significant (p is less than 0.03) correlation between blood pressure and sodium-excretion which disappeared during beta-blockade. No correlation between blood pressure and noradrenaline was seen during placebo, whereas during beta-blockade a significant (p is less than 0.003) correlation was observed. In contrast to the placebo period there was a significant positive correlation between sodium- and noradrenaline-excretion during long-term treatment with pindolol. It is concluded that whole-body balance of sodium and noradrenaline is an important factor in essential hypertension.

PMID:30857

[In vitro evaluation of adsorbents used in haemoperfusion (author's transl)].

The properties of six adsorbents for Haemoperfusion were investigated in vitro: Amberlite XAD-2; Amberlite XAD-4; Haemocol; collodion coated charcoal; albumine-collodion encapsulated charcoal and activated carbon fibers. Carbromal and diazepam are most quickly removed from aqueous solutions by Amberlite XAD-2 and XAD-4. Of the charcoal containing materials, Haemocol eliminates most rapidly carbromal and diazepam; while activated carbon fibers remove phenobarbital faster. When heparinized blood is perfused, a remarkable reduction in platelet count is observed. The drop is most pronounced with Amberlite XAD-2 and XAD-4, but even when using charcoal preparations the platelet depletion can reach 10% of the original number over 5 hours. Haemolysis is most pronounced with Amberlite XAD-2, XAD-4 and Haemocol. As the efficiency of the adsorbents towards the various drugs differ and as their adverse effects also vary, the decision for a particular material will have to be made according to the individual case.

[In vitro evaluation of adsorbents used in haemoperfusion (author's transl)]. The properties of six adsorbents for Haemoperfusion were investigated in vitro: Amberlite XAD-2; Amberlite XAD-4; Haemocol; collodion coated charcoal; albumine-collodion encapsulated charcoal and activated carbon fibers. Carbromal and diazepam are most quickly removed from aqueous solutions by Amberlite XAD-2 and XAD-4. Of the charcoal containing materials, Haemocol eliminates most rapidly carbromal and diazepam; while activated carbon fibers remove phenobarbital faster. When heparinized blood is perfused, a remarkable reduction in platelet count is observed. The drop is most pronounced with Amberlite XAD-2 and XAD-4, but even when using charcoal preparations the platelet depletion can reach 10% of the original number over 5 hours. Haemolysis is most pronounced with Amberlite XAD-2, XAD-4 and Haemocol. As the efficiency of the adsorbents towards the various drugs differ and as their adverse effects also vary, the decision for a particular material will have to be made according to the individual case.

PMID:30858

[Composition of the trace contaminants in the atmosphere of the Soiuz-22 space ship].

The Soyuz-22 space cabin atmosphere was studied for volatile organic trace contaminants. By gas chromatography the following constituents were identified: methane, ethane, heptane, methanol, ethanol, n-propanol, acetaldehyde, acetone, ethyl benzene. Except for acetone, concentrations of the above compounds were close to the values determined in the mock-up experiments.

[Composition of the trace contaminants in the atmosphere of the Soiuz-22 space ship]. The Soyuz-22 space cabin atmosphere was studied for volatile organic trace contaminants. By gas chromatography the following constituents were identified: methane, ethane, heptane, methanol, ethanol, n-propanol, acetaldehyde, acetone, ethyl benzene. Except for acetone, concentrations of the above compounds were close to the values determined in the mock-up experiments.

PMID:30868

The pediatric nurse practitioner: origins and challenges.

During the past decade, a new health professional has evolved--the pediatric nurse practitioner (PNP). Responding to warnings of a shortage of primary care physicians, the American Academy of Pediatrics helped encourage programs to train PNPs who would provide well-child care, working under a physician's supervision. Simultaneously, in response to changing attitudes by and toward nurses, the American Nurses' Association expressed support for the expanded role of nurses in direct patient care functions--an expansion that would supplement other new academic programs in advancing the status of nursing as an interdependent, rather than subsidiary, health profession. Although mutually aiming at improvements in health care, both professions thus acted with different motivations and goals that have produced ongoing conflicts. These conflicts have been intensified by the absence of long-range planning in federal programs that have supported training for nurse practitioners. This paper summarizes the history of the PNP movement and the unresolved problems created by this new health professional.

The pediatric nurse practitioner: origins and challenges. During the past decade, a new health professional has evolved--the pediatric nurse practitioner (PNP). Responding to warnings of a shortage of primary care physicians, the American Academy of Pediatrics helped encourage programs to train PNPs who would provide well-child care, working under a physician's supervision. Simultaneously, in response to changing attitudes by and toward nurses, the American Nurses' Association expressed support for the expanded role of nurses in direct patient care functions--an expansion that would supplement other new academic programs in advancing the status of nursing as an interdependent, rather than subsidiary, health profession. Although mutually aiming at improvements in health care, both professions thus acted with different motivations and goals that have produced ongoing conflicts. These conflicts have been intensified by the absence of long-range planning in federal programs that have supported training for nurse practitioners. This paper summarizes the history of the PNP movement and the unresolved problems created by this new health professional.

PMID:30880

Transport capacity, alkaline phosphatase activity and protein content of glutaraldehyde-treated cell forms of Escherichia coli.

Studies on the comparative transport capacity of various cell forms of Escherichia coli suggest that glutaraldehyde acts only in the outer regions of the cell envelope and to such an extent that transport of alpha-aminoisobutyric acid is reduced by 50%. Alkaline phosphatase activity in whole cells was severely impaired in the presence of alkaline glutaraldehyde and in NaCl-washed cells both acid and alkaline glutaraldehyde (0.01%) caused approximately 80-90% reduction in enzyme activity in 10 min. Protein content was reduced by only 10-15% with this concentration of glutaraldehyde, and cell volume decreased by the same extent. These results are discussed in terms of the mode of action of the disinfectant.

Transport capacity, alkaline phosphatase activity and protein content of glutaraldehyde-treated cell forms of Escherichia coli. Studies on the comparative transport capacity of various cell forms of Escherichia coli suggest that glutaraldehyde acts only in the outer regions of the cell envelope and to such an extent that transport of alpha-aminoisobutyric acid is reduced by 50%. Alkaline phosphatase activity in whole cells was severely impaired in the presence of alkaline glutaraldehyde and in NaCl-washed cells both acid and alkaline glutaraldehyde (0.01%) caused approximately 80-90% reduction in enzyme activity in 10 min. Protein content was reduced by only 10-15% with this concentration of glutaraldehyde, and cell volume decreased by the same extent. These results are discussed in terms of the mode of action of the disinfectant.

PMID:30881

Physico-chemical properties of mouse hepatitis virus (MHV-2) grown on DBT cell culture.

Some properties of a strain of mouse hepatitis virus, MHV-2, grown on DBT cells were determined using a plaque assay on the cells. Viral growth was not inhibited by the presence of actinomycin D or 5-iodo-2-deoxyuridine. MHV-2 was completely inactivated by ether, chloroform, sodium deoxycholate or beta-propiolactone, but showed a moderate resistance to trypsin. Heating at 56 C for 30 min did not completely abolish the virus infectivity. The virus was stable after heating at 50 C for 15 min in 1M-MgCl2 or 1M-MgSO4 as well as at 37 C for 60 min at pH 3.0 to 9.0. Infectivity was decreased to 1/100 and 1/400 after storing at 4 C for 30 days and 37 C for 24 hr, respectively. The virus passed through a 200-nm but not a 50-nm Sartorius membrane filter. The buoyant density of MHV-2 was 1.183 g/cm3 in sucrose gradient, and the fraction contained coronavirus-like particles measuring 70 to 130 nm in diameter. Survival rate was 10% after exposure to ultraviolet at 150 ergs/mm2. Freezing and thawing or sonication at 20 kc for 3 min did not affect the virus titer. No hemagglutinin was demonstrable with red blood cells of the chicken, Japanese quail, mouse, rat, hamster, guinea pig, sheep, bovine or human.

Physico-chemical properties of mouse hepatitis virus (MHV-2) grown on DBT cell culture. Some properties of a strain of mouse hepatitis virus, MHV-2, grown on DBT cells were determined using a plaque assay on the cells. Viral growth was not inhibited by the presence of actinomycin D or 5-iodo-2-deoxyuridine. MHV-2 was completely inactivated by ether, chloroform, sodium deoxycholate or beta-propiolactone, but showed a moderate resistance to trypsin. Heating at 56 C for 30 min did not completely abolish the virus infectivity. The virus was stable after heating at 50 C for 15 min in 1M-MgCl2 or 1M-MgSO4 as well as at 37 C for 60 min at pH 3.0 to 9.0. Infectivity was decreased to 1/100 and 1/400 after storing at 4 C for 30 days and 37 C for 24 hr, respectively. The virus passed through a 200-nm but not a 50-nm Sartorius membrane filter. The buoyant density of MHV-2 was 1.183 g/cm3 in sucrose gradient, and the fraction contained coronavirus-like particles measuring 70 to 130 nm in diameter. Survival rate was 10% after exposure to ultraviolet at 150 ergs/mm2. Freezing and thawing or sonication at 20 kc for 3 min did not affect the virus titer. No hemagglutinin was demonstrable with red blood cells of the chicken, Japanese quail, mouse, rat, hamster, guinea pig, sheep, bovine or human.

PMID:30887

Loss of the sole.

The sole of the foot in a wood merchant was lost when he trod on a circular saw which had been placed on the ground. The foot was resurfaced by immediate split skin grafts, and the result proved very satisfactory. The immediate grafting procedure took on the cancellous bone, and as an emergency procedure it is recommended while thought is being given to more elaborate procedures such as cross leg flap grafts or even amputation.

Loss of the sole. The sole of the foot in a wood merchant was lost when he trod on a circular saw which had been placed on the ground. The foot was resurfaced by immediate split skin grafts, and the result proved very satisfactory. The immediate grafting procedure took on the cancellous bone, and as an emergency procedure it is recommended while thought is being given to more elaborate procedures such as cross leg flap grafts or even amputation.

PMID:30882

[Fixation of free nitrogen in the soil and on the roots of citrus trees in the subtropics of the Georgian SSR].

The rate of biological nitrogen fixation was determined by the acetylene technique in soils and on the roots of orange, mandarin and lemon trees growing in red, yellow, podzolic, alluvial brown forest, and humus-calcareous soils. The minimum nitrogen fixation in podzolic soils was 3--8 kg of nitrogen per hectare per vegetative period. The maximum nitrogen fixation (48--51 kg N per hectare) was found in red and humus-calcareous soils of orange plantations. One dose of nitrogen fertilizers with liming increased the nitrogen fixing activity of subtropic podzolic soils of mandarin plantations whereas a triple dose inhibited the activity. The rate of nitrogen fixation by the root microflora was 3--4 times higher than that by the soil microflora.

[Fixation of free nitrogen in the soil and on the roots of citrus trees in the subtropics of the Georgian SSR]. The rate of biological nitrogen fixation was determined by the acetylene technique in soils and on the roots of orange, mandarin and lemon trees growing in red, yellow, podzolic, alluvial brown forest, and humus-calcareous soils. The minimum nitrogen fixation in podzolic soils was 3--8 kg of nitrogen per hectare per vegetative period. The maximum nitrogen fixation (48--51 kg N per hectare) was found in red and humus-calcareous soils of orange plantations. One dose of nitrogen fertilizers with liming increased the nitrogen fixing activity of subtropic podzolic soils of mandarin plantations whereas a triple dose inhibited the activity. The rate of nitrogen fixation by the root microflora was 3--4 times higher than that by the soil microflora.

PMID:30883

[DNA synthesis and degradation in the cells of Bacillus stearothermophilus].

ATP-dependent and ATP-independent synthesis of DNA was studied on nucleotide-permeable cells of Bacillus stearothermophilus. The effect of temperature, pH, ionic strength, and bivalent metal ions on both types of DNA synthesis was investigated as well as their susceptibility to an SH-blocking agent. The level of ATP-independent synthesis of DNA in the cells of Bac. stearothermophilus was found to be ten times higher than that in E. coli. In the semipermeable cells of Bac. stearothermophilus, 90% of DNA of the chromosome was accessible to their nucleases. The temperature optimum of the activity of DNA polymerases and nucleases in the cells treated with toluene coincided with the optimum of the bacterial growth.

[DNA synthesis and degradation in the cells of Bacillus stearothermophilus]. ATP-dependent and ATP-independent synthesis of DNA was studied on nucleotide-permeable cells of Bacillus stearothermophilus. The effect of temperature, pH, ionic strength, and bivalent metal ions on both types of DNA synthesis was investigated as well as their susceptibility to an SH-blocking agent. The level of ATP-independent synthesis of DNA in the cells of Bac. stearothermophilus was found to be ten times higher than that in E. coli. In the semipermeable cells of Bac. stearothermophilus, 90% of DNA of the chromosome was accessible to their nucleases. The temperature optimum of the activity of DNA polymerases and nucleases in the cells treated with toluene coincided with the optimum of the bacterial growth.

PMID:30884

[Exoprotease properties of Bacillus subtilis var. amyloliquefaciens capable of coagulating blood plasma].

The properties of the homogeneous exoprotease preparation from Bacillus subtilis varamyloliquefaciens 759 possessing the coagulase activity were studied. The enzyme is an alkaline protease, has the isopoint at pH 7.8, and not only clots blood plasmo but also hydrolyses such protein substrates as casein, hemoglobin, fibrinogen and fibrin. The enzyme is relatively stable at pH 6.0--9.0. Bivalent metal ions have virtually no effect on the enzyme activity though some of them stabilize it. The inhibitors PCMB and EDTA do not affect the activity of the enzyme whereas diisopropylfluorophosphate completely inactivates it. Fibrinogen is clotted by the enzyme only in the presence of blood plasma factors.

[Exoprotease properties of Bacillus subtilis var. amyloliquefaciens capable of coagulating blood plasma]. The properties of the homogeneous exoprotease preparation from Bacillus subtilis varamyloliquefaciens 759 possessing the coagulase activity were studied. The enzyme is an alkaline protease, has the isopoint at pH 7.8, and not only clots blood plasmo but also hydrolyses such protein substrates as casein, hemoglobin, fibrinogen and fibrin. The enzyme is relatively stable at pH 6.0--9.0. Bivalent metal ions have virtually no effect on the enzyme activity though some of them stabilize it. The inhibitors PCMB and EDTA do not affect the activity of the enzyme whereas diisopropylfluorophosphate completely inactivates it. Fibrinogen is clotted by the enzyme only in the presence of blood plasma factors.

PMID:30893

[Toxico-analytical study of tofizopam].

For the legal-toxicological identification on the Grandaxin--a new minor tranquillant of benzodiazepine type--a new method have been worked out. Identification by layer-chromatography and determination by UV-spectrophotometry appeared to be suitable for the study of 5 postmortal cases.

[Toxico-analytical study of tofizopam]. For the legal-toxicological identification on the Grandaxin--a new minor tranquillant of benzodiazepine type--a new method have been worked out. Identification by layer-chromatography and determination by UV-spectrophotometry appeared to be suitable for the study of 5 postmortal cases.

PMID:30885

[Dehydrogenase isoenzymatic spectrum of alanine, aspartic and glutamic acids in Candida albicans yeasts].

The isoenzyme spectrum of dehydrogenases of alanine, aspartic and glutamic acids requiring NAD and NADP as cofactors was studied in Candida albicans. The spectrum of aspartate dehydrogenase was found to depend on a cofactor being used. The isoenzyme systems are related to proteins which posess various physico-chemical and antigenic properties.

[Dehydrogenase isoenzymatic spectrum of alanine, aspartic and glutamic acids in Candida albicans yeasts]. The isoenzyme spectrum of dehydrogenases of alanine, aspartic and glutamic acids requiring NAD and NADP as cofactors was studied in Candida albicans. The spectrum of aspartate dehydrogenase was found to depend on a cofactor being used. The isoenzyme systems are related to proteins which posess various physico-chemical and antigenic properties.

PMID:30886

[Acidophilic obligate thermophilic bacteria, Bacillus acidocal-darius, isolated from the hot springs and soil of Kunashir Island].

Obligate thermophilic acidophilic cultures of Bacillus acidocaldarius were isolated from hot springs and soil of the Kunashir Island (the Kuril Islands) and Southern Sakhalin; their optimum temperature of growth is 65 degrees C and pH is 3.3--4.0. It has been shown for the first time that these organisms can be isolated from springs with either acidic or neutral and weakly alkaline pH values.

[Acidophilic obligate thermophilic bacteria, Bacillus acidocal-darius, isolated from the hot springs and soil of Kunashir Island]. Obligate thermophilic acidophilic cultures of Bacillus acidocaldarius were isolated from hot springs and soil of the Kunashir Island (the Kuril Islands) and Southern Sakhalin; their optimum temperature of growth is 65 degrees C and pH is 3.3--4.0. It has been shown for the first time that these organisms can be isolated from springs with either acidic or neutral and weakly alkaline pH values.

PMID:30911

Defining the histamine H2-receptor in brain: the interaction with LSD.

Two aspects of the complexities of the mode of action of drugs are described. One is the criteria and pitfalls of defining the interaction with specific receptors. The other is the need to consider each of the pharmacological effects of a drug as a concatenation of receptor events, because it has become clear that each drug may have substantial affinity for many specific receptors. Illustrating these ideas is a characterization of the histamine receptor linked to adenylate cyclase in brain. The activities of a series of H2-antagonists and H2-agaonists were shown to be the same on the histamine receptor linked to adenylate cyclase as on known H2-receptors. The KB values of antagonists and ED50 values of agonists were not distinguishable among these receptors. Notably, at high concentrations, the H1-antagonists are also competitive antagonists of the H2-receptor. Cyproheptadine has especially high affinity for the H2-receptor. It is the most potent H2-antagonist yet reported. Other published results are reviewed to show the variety of receptors that cyproheptadine has affinity for. Its affinity for serotonin receptors led us to examine other serotonin antagonists. On this H2-receptor linked to adenylate cyclase in homogenates of guinea pig hippocampus and cortex, D-LSD and D-2-bromo-LSD (BrLSD) were shown to be competitive antagonists of histamine. L-LSD, mescaline and psilocin were inactive. Noting congurency in the molecular structyre of D-LSD and known H2-antagonists, we predicted a new H2-antagonist. This prediction is shown to be correct: the compound has similar affinity to the H2-receptor as has LSD. The affinities of D-LSD and BrLSD for the H2-receptor are compared with their affinities for other receptors. The pharmacology of D-LSD and BrLSD is reviewed. Evidence is assembled that BrLSD has considerable central effects.

Defining the histamine H2-receptor in brain: the interaction with LSD. Two aspects of the complexities of the mode of action of drugs are described. One is the criteria and pitfalls of defining the interaction with specific receptors. The other is the need to consider each of the pharmacological effects of a drug as a concatenation of receptor events, because it has become clear that each drug may have substantial affinity for many specific receptors. Illustrating these ideas is a characterization of the histamine receptor linked to adenylate cyclase in brain. The activities of a series of H2-antagonists and H2-agaonists were shown to be the same on the histamine receptor linked to adenylate cyclase as on known H2-receptors. The KB values of antagonists and ED50 values of agonists were not distinguishable among these receptors. Notably, at high concentrations, the H1-antagonists are also competitive antagonists of the H2-receptor. Cyproheptadine has especially high affinity for the H2-receptor. It is the most potent H2-antagonist yet reported. Other published results are reviewed to show the variety of receptors that cyproheptadine has affinity for. Its affinity for serotonin receptors led us to examine other serotonin antagonists. On this H2-receptor linked to adenylate cyclase in homogenates of guinea pig hippocampus and cortex, D-LSD and D-2-bromo-LSD (BrLSD) were shown to be competitive antagonists of histamine. L-LSD, mescaline and psilocin were inactive. Noting congurency in the molecular structyre of D-LSD and known H2-antagonists, we predicted a new H2-antagonist. This prediction is shown to be correct: the compound has similar affinity to the H2-receptor as has LSD. The affinities of D-LSD and BrLSD for the H2-receptor are compared with their affinities for other receptors. The pharmacology of D-LSD and BrLSD is reviewed. Evidence is assembled that BrLSD has considerable central effects.

PMID:30927

[Manipulated hyperacidification of autochthonous tumors].

Measurement on 3,4-benzopyrene- and methylcholanthrene-induced tumours of the rat (and mouse) showed that the multiple established manipulated hyperacidification of transplantation tumours to values about pH 6 is possible also on autochthonous tumours.

[Manipulated hyperacidification of autochthonous tumors]. Measurement on 3,4-benzopyrene- and methylcholanthrene-induced tumours of the rat (and mouse) showed that the multiple established manipulated hyperacidification of transplantation tumours to values about pH 6 is possible also on autochthonous tumours.

PMID:30928

[Phylogenetic aspects of acquired immunity].

A review of literature on phylogenesis of acquired immunity shows an increasing activity and potential of this complex apparatus. This system is responsible for the immunosurveillance, i.e. the control and recognition of transformed cells. Obviously the functions and morphology of the immune competent apparatus become more active and specific with growing complexity of living conditions. Since organisms become the more vulnerable the higher stages of development are reached, the sense of this evolution lies in protecting these organisms against environmental influences and in allowing survival. Recognition and elimination of malignant cells is part of this capacity acquired by evolution.

[Phylogenetic aspects of acquired immunity]. A review of literature on phylogenesis of acquired immunity shows an increasing activity and potential of this complex apparatus. This system is responsible for the immunosurveillance, i.e. the control and recognition of transformed cells. Obviously the functions and morphology of the immune competent apparatus become more active and specific with growing complexity of living conditions. Since organisms become the more vulnerable the higher stages of development are reached, the sense of this evolution lies in protecting these organisms against environmental influences and in allowing survival. Recognition and elimination of malignant cells is part of this capacity acquired by evolution.

PMID:30929

[The time lapse of the cytostatic effect of ifosfamide].

The time lapse of the effect of ifosfamid on the solid DS carcinosarcoma has been studied using 204 Wistar rats. The main results and the conclusions are as follows: 1. The transplantability of the tumor is abolished two hours after the i.v. application of 180 mg/kg isofamid (cessation of tumor cell proliferation). 2. Yet, the tumor tissue to be grafted is not damaged thoroughly by this treatment. It is possible that the still viable tumor cells were killed by the non-suppressed immune system of the recipients. 3. As determined by trypan blue dye exclusion and registration of glycolytic activity, the main part of tumor cells remains viable. As lately as 4 days after the therapy 80% of the cells incorporate trypan blue and the glycolytic activity is inhibited in the order of 80%. 4. It is to be expected that within two hours, a period sufficient for proliferation inhibition of tumor cells, only 30% of the active form of the drug administered can be found in the tumor. In this context the toxification (activation) kinetics of ifosfamid is discussed and an optimized, programmed infusion is considered. 5. The treatment with ifosfamid does not affect at least up to the third day the tumor hyperacidification attainable by a long-lasting glucose infusion.

[The time lapse of the cytostatic effect of ifosfamide]. The time lapse of the effect of ifosfamid on the solid DS carcinosarcoma has been studied using 204 Wistar rats. The main results and the conclusions are as follows: 1. The transplantability of the tumor is abolished two hours after the i.v. application of 180 mg/kg isofamid (cessation of tumor cell proliferation). 2. Yet, the tumor tissue to be grafted is not damaged thoroughly by this treatment. It is possible that the still viable tumor cells were killed by the non-suppressed immune system of the recipients. 3. As determined by trypan blue dye exclusion and registration of glycolytic activity, the main part of tumor cells remains viable. As lately as 4 days after the therapy 80% of the cells incorporate trypan blue and the glycolytic activity is inhibited in the order of 80%. 4. It is to be expected that within two hours, a period sufficient for proliferation inhibition of tumor cells, only 30% of the active form of the drug administered can be found in the tumor. In this context the toxification (activation) kinetics of ifosfamid is discussed and an optimized, programmed infusion is considered. 5. The treatment with ifosfamid does not affect at least up to the third day the tumor hyperacidification attainable by a long-lasting glucose infusion.

PMID:30930

[Effect of different temperature fractions of RNA on allogenic inhibition of hematopoietic stem cells of mouse bone marrow and embryonal liver].

In the system of non-syngeneic transfer of stem hemopoietic cells, the preliminary incubation of the cells of bone marrow or embryonic liver of the C57BL mice with different temperature RNA fractions isolated from the spleen of (CBAXC57BL) F1 was shown to lead to the complete or partial restoration of the colony forming ability of the donor cells. The 63 degrees RNA fraction was shown to have the greatest restorative effect.

[Effect of different temperature fractions of RNA on allogenic inhibition of hematopoietic stem cells of mouse bone marrow and embryonal liver]. In the system of non-syngeneic transfer of stem hemopoietic cells, the preliminary incubation of the cells of bone marrow or embryonic liver of the C57BL mice with different temperature RNA fractions isolated from the spleen of (CBAXC57BL) F1 was shown to lead to the complete or partial restoration of the colony forming ability of the donor cells. The 63 degrees RNA fraction was shown to have the greatest restorative effect.

PMID:30932

Effects of ovine hydatid cyst fluid in sheep before and after treatment with hydrocortisone, antihistamines and atropine.

The cardiovascular and respiratory responses to scolex-free ovine hydatid cyst fluid were studied in 65 sodium pentobarbital-anesthetized sheep. The arterial blood pressure (ABP), central venous pressure (CVP), stethogram and electrocardiogram were recorded. Intra-venous administration of 10 ml or less hydatid fluid brought about moderate to severe fall in ABP and rapid respiration or permanent respiratory cessation in majority of the animals. Forty six percent of the sheep died of circulatory and respiratory failure after the first injection or the hydatid fluid. Boiled hydatid fluid did not lose its potency to evoke the above responses. Hydrocortisone, given 200 mg daily for seven days, failed to prevent the reactions to hydatid fluid. Intravenous administration of the antihistamines chlorpheniramine, 4 mg/kg, and antazoline, 5 mg/kg, caused only partial prevention of the responses in 8 out of 15 responsive sheep. Pretreatment of the animals with atropine, 0.5--1 mg/kg subcutaneously, did not block the reactions. The cardiovascular and respiratory responses to ovine hydatid fluid may be due to antigen-antibody reactions or some toxic component of the fluid.

Effects of ovine hydatid cyst fluid in sheep before and after treatment with hydrocortisone, antihistamines and atropine. The cardiovascular and respiratory responses to scolex-free ovine hydatid cyst fluid were studied in 65 sodium pentobarbital-anesthetized sheep. The arterial blood pressure (ABP), central venous pressure (CVP), stethogram and electrocardiogram were recorded. Intra-venous administration of 10 ml or less hydatid fluid brought about moderate to severe fall in ABP and rapid respiration or permanent respiratory cessation in majority of the animals. Forty six percent of the sheep died of circulatory and respiratory failure after the first injection or the hydatid fluid. Boiled hydatid fluid did not lose its potency to evoke the above responses. Hydrocortisone, given 200 mg daily for seven days, failed to prevent the reactions to hydatid fluid. Intravenous administration of the antihistamines chlorpheniramine, 4 mg/kg, and antazoline, 5 mg/kg, caused only partial prevention of the responses in 8 out of 15 responsive sheep. Pretreatment of the animals with atropine, 0.5--1 mg/kg subcutaneously, did not block the reactions. The cardiovascular and respiratory responses to ovine hydatid fluid may be due to antigen-antibody reactions or some toxic component of the fluid.

PMID:30936

Hypercarbia at birth: a possible role in the pathogenesis of intraventricular hemorrhage.

To test the hypothesis that birth asphyxia has a role in the etiology of intraventricular hemorrhage (IVH), blood was collected from the umbilical artery (UA) at birth in 28 premature infants of 26 to 29 weeks gestation and analyzed for hydrogen ion concentration [H+], PCO2, standard bicarbonate level, and lactic acid level. The infants were followed up throughout their nursery stay until a diagnosis of IVH could be made or excluded, either by autopsy or clinical findings. Infants with IVH had lower Apgar scores. There were no differences in UA [H+] or bicarbonate or lactic acid levels. However, infants with IVH had a significantly higher UA PCO2. Although the difference appeared relatively small, the increase in PCO2 during labor may have been relatively large. It is concluded that hypercarbia, possibly by increasing cerebral blood flow, may be one important factor in the genesis of IVH.

Hypercarbia at birth: a possible role in the pathogenesis of intraventricular hemorrhage. To test the hypothesis that birth asphyxia has a role in the etiology of intraventricular hemorrhage (IVH), blood was collected from the umbilical artery (UA) at birth in 28 premature infants of 26 to 29 weeks gestation and analyzed for hydrogen ion concentration [H+], PCO2, standard bicarbonate level, and lactic acid level. The infants were followed up throughout their nursery stay until a diagnosis of IVH could be made or excluded, either by autopsy or clinical findings. Infants with IVH had lower Apgar scores. There were no differences in UA [H+] or bicarbonate or lactic acid levels. However, infants with IVH had a significantly higher UA PCO2. Although the difference appeared relatively small, the increase in PCO2 during labor may have been relatively large. It is concluded that hypercarbia, possibly by increasing cerebral blood flow, may be one important factor in the genesis of IVH.

PMID:30937

Serum gamma-glutamyl transpeptidase acitvity: a chemical determinant of alcohol consumption during adolescence.

The drinking habits of 55 adolescents, aged 12 to 22 years, were evaluated in light of the current presumed upsurge in adolescent alcohol use. SGPT, SGOT, and alkaline phosphatase concentrations were essentially normal in all subjects. Serum gamma-glutamyl transpeptidase (GGTP) concentrations were elevated in 12 of 15 adolescents who consumed six or more drinks per day. It is suggested that this test may warrant inclusion among other targeted screening procedures performed in teenage patients suspected of heavy alcohol consumption.

Serum gamma-glutamyl transpeptidase acitvity: a chemical determinant of alcohol consumption during adolescence. The drinking habits of 55 adolescents, aged 12 to 22 years, were evaluated in light of the current presumed upsurge in adolescent alcohol use. SGPT, SGOT, and alkaline phosphatase concentrations were essentially normal in all subjects. Serum gamma-glutamyl transpeptidase (GGTP) concentrations were elevated in 12 of 15 adolescents who consumed six or more drinks per day. It is suggested that this test may warrant inclusion among other targeted screening procedures performed in teenage patients suspected of heavy alcohol consumption.

PMID:30933

Acid-base and oxidation-reduction relationships.

pH, the symbol for "hydrogen-ion concentration", is a series of dimensionless "units" that have only general significance. The author shows that, when considered on the basis of the relationship to oxidation-reduction, the relative significance of any pair of coordinates becomes more significant. However, the theoretical relationship as currently accepted by the Nernst equation, i.e. a shift of 59.1 milivolts for each shift of 1.0 pH, does not apply to macromolecular systems, such as in vivo. The author solved this difficulty by plotting the corrdinates graphically by bisecting pH relationships at 7.0 and oxidation-reduction relationships at Eh 0.0 milivolts, forming four quadrants. With this scheme the significance of any pair of coordinates can be readily recognized. The application of this method to biology and medicine is shown in the companion paper "pH and Eh relationships in the body".

Acid-base and oxidation-reduction relationships. pH, the symbol for "hydrogen-ion concentration", is a series of dimensionless "units" that have only general significance. The author shows that, when considered on the basis of the relationship to oxidation-reduction, the relative significance of any pair of coordinates becomes more significant. However, the theoretical relationship as currently accepted by the Nernst equation, i.e. a shift of 59.1 milivolts for each shift of 1.0 pH, does not apply to macromolecular systems, such as in vivo. The author solved this difficulty by plotting the corrdinates graphically by bisecting pH relationships at 7.0 and oxidation-reduction relationships at Eh 0.0 milivolts, forming four quadrants. With this scheme the significance of any pair of coordinates can be readily recognized. The application of this method to biology and medicine is shown in the companion paper "pH and Eh relationships in the body".

PMID:30934

pH and Eh relationships in the body.

This report concerns application of the graphical method for representing pH and Eh relationships in macromolecular systems (see previous paper) to in vivo studies. The author presents reasons for concluding that controlled measurements of urine are satisfactory indicators of changes in pH and Eh in the body whereas blood studies remain relatively constant. The original concept had to be modified because of two little known "reversing phenomena". One is well known to physicians as the "acid rebound" because of the acid reaction of urine when an excess of a base is administered. This is a paradox because it would be expected to be more alkaline. The second phenomenon occurs following hyperoxidation, such as in narcotic addiction, and results in reduction. Both hyperalkalinity and hyperoxidation result in an acid reaction. The author concludes that they are phases of a single phenomenon. It is the basis for "Chapman's law": Unfavorable effects on the body cause the urine pH and Eh to shift away from normal whereas favorable effects cause them to shift toward normal.

pH and Eh relationships in the body. This report concerns application of the graphical method for representing pH and Eh relationships in macromolecular systems (see previous paper) to in vivo studies. The author presents reasons for concluding that controlled measurements of urine are satisfactory indicators of changes in pH and Eh in the body whereas blood studies remain relatively constant. The original concept had to be modified because of two little known "reversing phenomena". One is well known to physicians as the "acid rebound" because of the acid reaction of urine when an excess of a base is administered. This is a paradox because it would be expected to be more alkaline. The second phenomenon occurs following hyperoxidation, such as in narcotic addiction, and results in reduction. Both hyperalkalinity and hyperoxidation result in an acid reaction. The author concludes that they are phases of a single phenomenon. It is the basis for "Chapman's law": Unfavorable effects on the body cause the urine pH and Eh to shift away from normal whereas favorable effects cause them to shift toward normal.

PMID:30940

Rates of block by procaine and benzocaine and the procaine-benzocaine interaction at the node of Ranvier.

1. Action potentials and their maximum rates of rise, VA, were measured in single myelinated nerve fibres of the frog, Rana esculenta at room temperature. 2. On applying 1 mM procaine (pH 7.2) at 20 Hz stimulus frequency, half of the final VA reduction was reached at ton = 0.27 s; on applying 0.5 mM benzocaine (pH 7,2) at 50 HZ, ton was 0.12 s. Increasing the stimulus frequency between 2 and 50 HZ increased the rate of block by procaine but not by benzocaine. 3. Recovery in Ringer solution (pH 7.2) from 30-s treatment with 1 mM procaine (pH 7.2), the equieffective 0.15 mM procaine (pH 8.9) and from 0.5 mM benzocaine (pH 7.2) was 54%, 31% and 70%, respectively, within 1 s. 4. Changing between alkaline Ringer solution (pH 8.9) and 1 mM procaine (pH 7.2) led to transitory excessive block. Changing between 1 mM procaine (pH 7.2) and acid Ringer solution (pH 6.0) and washing out 10 mM procaine (pH 5.5) with neutral Ringer solution also led to a non-monotonic change in VA. 5. If hyperpolarizing pulses (30 ms, 20 mV) preceded the stimuli, changing the frequency of the pulse pairs led to a gradual moderate relief of block in procaine, turning off prepulses (at 10 HZ) to a gradual increase of block. In benzocaine changing from 1 to 10 HZ had no effect but turning off prepulses led to a prompt large increase of block. In procaine + benzocaine the membrane responded much as in benzocaine alone. At 1 HZ (prepulses) VA in 0.4 mM procaine was smaller than in 0.4 mM procaine + 0.3 mM benzocaine. 6. These phenomena can be explained on the assumption of voltage-dependent binding of benzocaine and procaine to a common receptor. The rate of block appears to be limited by access to the receptor, more in the case of benzocaine than of procaine.

Rates of block by procaine and benzocaine and the procaine-benzocaine interaction at the node of Ranvier. 1. Action potentials and their maximum rates of rise, VA, were measured in single myelinated nerve fibres of the frog, Rana esculenta at room temperature. 2. On applying 1 mM procaine (pH 7.2) at 20 Hz stimulus frequency, half of the final VA reduction was reached at ton = 0.27 s; on applying 0.5 mM benzocaine (pH 7,2) at 50 HZ, ton was 0.12 s. Increasing the stimulus frequency between 2 and 50 HZ increased the rate of block by procaine but not by benzocaine. 3. Recovery in Ringer solution (pH 7.2) from 30-s treatment with 1 mM procaine (pH 7.2), the equieffective 0.15 mM procaine (pH 8.9) and from 0.5 mM benzocaine (pH 7.2) was 54%, 31% and 70%, respectively, within 1 s. 4. Changing between alkaline Ringer solution (pH 8.9) and 1 mM procaine (pH 7.2) led to transitory excessive block. Changing between 1 mM procaine (pH 7.2) and acid Ringer solution (pH 6.0) and washing out 10 mM procaine (pH 5.5) with neutral Ringer solution also led to a non-monotonic change in VA. 5. If hyperpolarizing pulses (30 ms, 20 mV) preceded the stimuli, changing the frequency of the pulse pairs led to a gradual moderate relief of block in procaine, turning off prepulses (at 10 HZ) to a gradual increase of block. In benzocaine changing from 1 to 10 HZ had no effect but turning off prepulses led to a prompt large increase of block. In procaine + benzocaine the membrane responded much as in benzocaine alone. At 1 HZ (prepulses) VA in 0.4 mM procaine was smaller than in 0.4 mM procaine + 0.3 mM benzocaine. 6. These phenomena can be explained on the assumption of voltage-dependent binding of benzocaine and procaine to a common receptor. The rate of block appears to be limited by access to the receptor, more in the case of benzocaine than of procaine.

PMID:30941

Chloride binding and the Bohr effect of human fetal erythrocytes and HbFII solutions.

1. We have observed that the alkaline Bohr effect of washed human fetal erythrocytes was larger than in human adult intact red cells, in physiological conditions of pH, PCO2 and temperature. This was also observed independently of the presence of CO2 and of 2,3 diphosphoglycerate (fresh or stored erythrocytes). 2. Experiments performed in purified HbFII and HbA1 solutions and direct titration of protons released upon oxygenation confirmed the larger alkaline Bohr effect of fetal hemoglobin, at physiological ionic strength. 3. At low chloride concentration HbFII solutions had an alkaline Bohr effect identical to that measured in HbA1 solutions. 4. Titration of purified Hb solutions with increasing concentrations of NaCl evidenced a lower O2 linked chloride binding by HbFII and predominantly at acid pH. 5. It is concluded that the larger alkaline Bohr effect of fetal erythrocytes of HbFII solutions is related to a diminished acid Bohr effect, due to the lower affinity of HbFII for chloride anions. 6. The physiological interest of these results for placental O2 transfer (double Bohr effect) and O2 delivery to the foetus is discussed.

Chloride binding and the Bohr effect of human fetal erythrocytes and HbFII solutions. 1. We have observed that the alkaline Bohr effect of washed human fetal erythrocytes was larger than in human adult intact red cells, in physiological conditions of pH, PCO2 and temperature. This was also observed independently of the presence of CO2 and of 2,3 diphosphoglycerate (fresh or stored erythrocytes). 2. Experiments performed in purified HbFII and HbA1 solutions and direct titration of protons released upon oxygenation confirmed the larger alkaline Bohr effect of fetal hemoglobin, at physiological ionic strength. 3. At low chloride concentration HbFII solutions had an alkaline Bohr effect identical to that measured in HbA1 solutions. 4. Titration of purified Hb solutions with increasing concentrations of NaCl evidenced a lower O2 linked chloride binding by HbFII and predominantly at acid pH. 5. It is concluded that the larger alkaline Bohr effect of fetal erythrocytes of HbFII solutions is related to a diminished acid Bohr effect, due to the lower affinity of HbFII for chloride anions. 6. The physiological interest of these results for placental O2 transfer (double Bohr effect) and O2 delivery to the foetus is discussed.