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California State Journal of Medicine Aug 1904
PubMed: 18733166
DOI: No ID Found -
Journal of Virology May 1971Infectious ribonucleic acids (IRNA) of Venezuelan equine encephalitis and Eastern equine encephalitis viruses were observed to form noninfectious complexes with a basic...
Infectious ribonucleic acids (IRNA) of Venezuelan equine encephalitis and Eastern equine encephalitis viruses were observed to form noninfectious complexes with a basic polyamino acid, poly-l-lysine. Original infectivity was recovered from the complexes by digestion of the polylysine with Pronase, and partial recovery was effected by treatment with sodium dodecyl sulfate. Infectivity could not be recovered from the complexes containing polylysine of 100,000 molecular weight by changes in ionic strength, pH, or by treatment with phenol, deoxycholate, or digitonin. Masking of infectivity by polylysine was demonstrated in vivo as well as by plaque assay in tissue culture. Poly-l-lysine preparations of high molecular weight (44,000 to 100,000) were more effective than low molecular weight (3,000) materials in masking infectivity of IRNA. When complexes, in which infectivity had been masked by low molecular weight polylysine, were suspended in 1 m NaCl, some infectivity was recovered. Complexes of polylysine-IRNA differed from control IRNA alone in (i) resistance to inactivation by ribonuclease, (ii) sedimentation patterns in sucrose gradient centrifugation, and (iii) stability of recoverable infectivity during different physical treatments.
Topics: Animals; Bile Acids and Salts; Centrifugation, Density Gradient; Chick Embryo; Chickens; Cold Temperature; Culture Techniques; Digitalis Glycosides; Encephalitis Virus, Venezuelan Equine; Encephalitis Viruses; Fibroblasts; Hot Temperature; Hydrogen-Ion Concentration; Lysine; Mice; Molecular Weight; Peptide Hydrolases; Phenols; Polyamines; RNA, Viral; Sodium; Streptomyces; Sucrose; Sulfates; Ultracentrifugation; Ultraviolet Rays; Virus Cultivation
PubMed: 5557681
DOI: 10.1128/JVI.7.5.595-602.1971 -
The Journal of Biological Chemistry Jul 1983Previous models of digitalis genin interaction with the (Na+,K+)-ATPase system (the putative receptor for such drugs) were deficient in explaining the (Na+,K+)-ATPase...
Previous models of digitalis genin interaction with the (Na+,K+)-ATPase system (the putative receptor for such drugs) were deficient in explaining the (Na+,K+)-ATPase inhibitory activity of a number of digitalis genin analogues. With rat brain (Na+,K+)-ATPase we observed that the C-17 side chain carbonyl (C = O) oxygen distance of a given genin in relation to its position in the reference compound digitoxigenin was the primary determinant of its biological activity. With a number of genin analogues, we observed a strict correlation of this structural parameter with its binding site compatibility as well as inhibitory potency with respect to the (Na+,K+)-ATPase. In every case the correlation to inhibition data was obtained using a minimum energy conformation for the genin structure. The general applicability of that model is now proposed based on the following observations. The carbonyl oxygen position versus the biological activity relationship fully holds with (Na+,K+)-ATPase preparations from other tissues and species and also when different binding conditions are used for the enzyme genin interaction. The relationship is equally valid for the K+-p-nitrophenyl phosphatase activity. Correlations of the data obtained under these various conditions provide further support for this relationship and for the concept that altered affinities of the enzyme for a given genin under different binding conditions reflect conformational variations of a single binding site.
Topics: Animals; Brain; Cats; Digitoxigenin; Kidney; Kinetics; Ligands; Myocardium; Sodium-Potassium-Exchanging ATPase; Structure-Activity Relationship; Swine
PubMed: 6305971
DOI: No ID Found -
The Journal of Clinical Investigation Jan 1961
PubMed: 16695846
DOI: 10.1172/JCI104236 -
British Journal of Pharmacology and... Mar 1967
Topics: Animals; Digitoxin; Dogs; Ethanolamines; Heart; Heart Conduction System; Heart Rate; Heart Ventricles; In Vitro Techniques; Ouabain; Reserpine; Ventricular Fibrillation
PubMed: 4382326
DOI: 10.1111/j.1476-5381.1967.tb01961.x -
British Medical Journal Mar 1969
Topics: Anti-Bacterial Agents; Digitalis Glycosides; Drug-Related Side Effects and Adverse Reactions; Humans; Medication Systems, Hospital; Pharmaceutical Preparations
PubMed: 5764696
DOI: No ID Found -
Applied Microbiology Dec 1968The relationship was investigated between various chemical or pharmaceutical production processes and the extent of microbial contamination, of natural origin, of the...
The relationship was investigated between various chemical or pharmaceutical production processes and the extent of microbial contamination, of natural origin, of the resulting products. The products contained active ingredients of vegetable, enzymatic, or animal origin. It was concluded that (i) vegetable products practically free from microbes can be produced if the proper manufacturing steps are taken; (ii) sterilization of the media used to manufacture antibiotics, etc., produces products with little contamination; and (iii) products containing extracts of animal organs require careful refrigeration and addition of preservatives to produce acceptable levels of microbial contamination.
Topics: Bacteria; Digitalis; Drug Industry; Methods; Microbiology; Pancreatic Extracts; Penicillins; Pharmaceutic Aids; Pharmaceutical Preparations; Pharmacognosy; Pilocarpine; Plants, Medicinal; Plants, Toxic; Refrigeration; Sterilization; Thyroid Gland
PubMed: 5726165
DOI: 10.1128/am.16.12.1924-1928.1968 -
British Journal of Clinical Pharmacology Jul 19781 The properties of a recently introduced digitalis glycoside, 4-beta-methyl digoxin (medigoxin) were compared to those of a standard digoxin preparation. Using a... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
1 The properties of a recently introduced digitalis glycoside, 4-beta-methyl digoxin (medigoxin) were compared to those of a standard digoxin preparation. Using a radioimmunoassay (RIA) technique, serial plasma levels were recorded for 8 h following a single oral dose in five fasting volunteer subjects, and urinary glycoside elimination was measured for 4 consecutive days after dosage by use of a modification of the RIA method. 2 It was found that this RIA was suitable for plasma level measurement of both digoxin and midigoxin by reference to appropriate standard curves. Comparison of the plasma level profiles of these two drugs showed that medigoxin was very rapidly absorbed with peak levels occurring within 15--30 min, while digoxin produced peak levels after 45--75 min. The area under the plasma level-time curve produced by medigoxin was also consistently greater than that produced by digoxin, even though the medigoxin dose used was smaller. Quantitative comparison of these areas after adjustment to compensate for differing doses showed that medigoxin is considerably more biologically available than digoxin under study conditions (ratio 1.6 +/- 0.25:1), and comparison of quantitative urinary elimination suggested that medigoxin is eliminated in the urine to a lesser extent than digoxin and therefore it undergoes more metabolism and/or hepato-biliary elimination.
Topics: Adult; Biological Availability; Digoxin; Humans; Male; Time Factors
PubMed: 666950
DOI: 10.1111/j.1365-2125.1978.tb01686.x -
California Medicine Oct 1953The hypotensive action of veratrum viride given intravenously was studied in 24 patients, 22 of them hypertensive and 2 normotensive. Vasodepression of considerable but...
The hypotensive action of veratrum viride given intravenously was studied in 24 patients, 22 of them hypertensive and 2 normotensive. Vasodepression of considerable but variable degree was obtained in all patients. Maximum hypotension occurred 8 to 15 minutes after injection and relative hypotension usually lasted at least two hours. In four patients subnormal hypotension occurred but there were no clinical manifestations of shock. The blood pressure rose promptly when pressor drugs were administered.A dose of 0.3 to 0.5 mg. brought about a satisfactory decrease in blood pressure. The degree of decrease was affected by the speed of administration and in a few patients by idiosyncratic sensitivity to the drug. Veratrum has an extravagal action on the pulse rate, and in that and other respects resembles digitalis. Veratrum should be given with caution to digitalized patients. Atropine reduced but did not abolish the hypotensive effect of veratrum, and was more effective when given before veratrum. This indicates that the parasympathomimetic action of veratrum is important in the mechanism of blood pressure reduction.
Topics: Blood Pressure; Cardiovascular System; Heart Rate; Hematinics; Hypertension; Hypotension; Injections, Intravenous; Parasympathomimetics; Pharmaceutical Preparations; Plant Extracts; Vasoconstrictor Agents; Veratrum; Veratrum Alkaloids; Vitamin B 12
PubMed: 13094542
DOI: No ID Found -
Japanese Journal of Pharmacology Dec 1989Antiarrhythmic effects of the new drug KT-362, which was reported to suppress Na and Ca currents of cardiac cells and also to suppress intracellular Ca release in...
Antiarrhythmic effects of the new drug KT-362, which was reported to suppress Na and Ca currents of cardiac cells and also to suppress intracellular Ca release in isolated smooth muscle preparations, were examined using two-stage coronary ligation-, digitalis- and adrenaline-induced ventricular arrhythmias in the dog. Intravenous KT-362 at 10 mg/kg suppressed coronary ligation arrhythmia both at 24 and 48 hr after ligation, and the minimum effective plasma concentrations for arrhythmias induced by 24 hr coronary ligation and 48 hr coronary ligation were 6.1 +/- 1.7 and 8.6 +/- 2.7 micrograms/ml, respectively. Antiarrhythmic effects were accompanied by transient hypotension. Oral administration of 70-100 mg/kg was also effective on 24 hr coronary ligation arrhythmia. However, there was no prominent hypotension in these experiments. Intravenous KT-362 at 3 mg/kg suppressed digitalis arrhythmia; and the minimum effective plasma concentration was 3.3 +/- 1.2 micrograms/ml, which was lower than the effective plasma concentrations for coronary ligation arrhythmias. Intravenous KT-362 at 1 mg/kg also suppressed adrenaline arrhythmia; and the minimum effective plasma concentration was 1.0 +/- 0.1 microgram/ml, the lowest among the effective plasma concentrations. These pharmacological profiles of KT-362 are quite different from those of class 4 Ca antagonists, but similar to those of class 1 drugs such as propafenone. Though KT-362 has a hypotensive effect, it is effective on canine ventricular arrhythmias; thus its clinical usefulness for supraventricular and ventricular arrhythmias is expected.
Topics: Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Calcium Channel Blockers; Coronary Vessels; Digitalis; Dogs; Epinephrine; Female; Male; Plants, Medicinal; Plants, Toxic; Sodium Channels; Thiazepines
PubMed: 2559225
DOI: 10.1254/jjp.51.475