Biomedical subjects
J C Miller
Publications and source records attributed to J C Miller.
Dopamine receptor-coupled modulation of the K+-depolarized overflow of 3H-acetylcholine from rat striatal slices: alteration after chronic haloperidol and alpha-methyl-p-tyrosine pretreatment.
Explore the source record for details and available documents.
Effects of haloperidol and apomorphine on the K+-depolarized overflow of [3H] dopamine from rat striatal slices.
Explore the source record for details and available documents.
The effects of barbiturates on the metabolism of phosphatidic acid and phosphatidylinositol in rat brain synaptosomes.
Barbiturates and diphenylhydantoin inhibit the carbamoylcholine-stimulated increase in 32P incorporation into phosphatidylinositol and phosphatidic acid, but have a relatively slight effect on the incorporation of 32P into these lipids in the absence of carbamoylcholine and no effect on 32P incorporation into phosphatidylcholine and phosphatidylethanolamine. Inhibition of the carbamoylcholine-stimulated increase was observed for pentobarbital, thiopental, phenobarbital, 5-(1,3-dimethylbutyl)-5-ethylbarbiturate, (+)- and (-)-5-ethyl-N-methyl-5-propylbarbituate and diphenylhydantoin. Similar concentrations of barbiturates and diphenylhydantoin were previously reported to inhibit the K+-stimulated Ca2+ influx, and therefore other agents that affect Ca2+ influx were tested to find whether they had any effect on 32P incorporation into these lipids. K+ (35 mM) increases 32P incorporation into phosphatidic acid, but to a smaller degree than 100 micrometer-carbamoylcholine, and its effect was inhibited by pentobarbital. Veratridine (75 micrometer) does not increase 32P incorporation into either phosphatidic acid or phosphatidylinositol, but did inhibit the carbamoylcholine-stimulated increase in 32P incorporation into phosphatidylinositol. The possible relationship between the phospholipid effect and stimulated Ca2+ influx is discussed.
Prediction of the timing of the adolescent growth spurt from ossification events in hand-wrist films.
Explore the source record for details and available documents.
[Towards a nursing gerontology. (1)].
Explore the source record for details and available documents.
[Towards a nursing gerontology. (2)].
Explore the source record for details and available documents.
The 24 hour cycle and nocturnal depression of human cardiac output.
The NASA-developed version of the impedance plethysmographic method for the determination of left ventricular stroke volume was applied to the investigation of daily variation of cardiovascular function. Hourly determinations of cardiac output and arterial pressure (auscultation) were obtained from two male subjects over the course of a 48-h period in the laboratory. Cardiac output displayed a strong 24-h cycle of nearly 1 1/min, peak-to-peak, cresting in the late evening hours. Nocturnal sleep was associated with a reduction of cardiac output characterized by a minimum in the early morning hours. It was concluded that a nocturnal, 24-h cyclic depression of waking cardiac output is exacerbated during sleep periods, and mechanisms for this exacerbation were suggested.
Phosphatidate phosphatase: activity and properties in fetal and adult rat lung.
The purpose of this work is to compare the properties of phosphatidate phosphatase (L-alpha-phosphatidate phosphohydrolase, EC 3.1.3.4) in fetal and adult rat lung and to establish the developmental profile of activity measured under optimal conditions. The maximal pH of 6.0--7.0 and the inhibition by fluoride, Ca2+ and detergents were simialr for both adult and fetal. Phosphatidate phosphohydrolase activity was located in both mitochondria and microsomes. The localizations of marker enzymes indicated that the activity in these subfractions was not a result of cross contaminations. Very low activity was detected in the supernatant fraction and no Mg2+ requirement was demonstrable. The activity in the particulate fraction was about 50% of the adult from 18 day gestation until birth. Following birth, the activity rapidly increased to adult levels. Dipalmitoyl, dioleoyl and diacyl glycerol 3-phosphates are all utilized well as substrates. 1,2-dipalmitoyl-sn-glycerol 3-phosphate was hydrolyzed faster under maximal conditions. The velocity-substrate curves tended to be sigmoidal, particularly when 1,2-dipalmitoyl-sn-glycerol 3-phosphate was the substrate. Estimated apparent Km values of 0.02--0.03 mM were obtained for fetal and adult preparations.
A bone resorbing substance from bovine serum albumin (brA).
Explore the source record for details and available documents.
Reduction of heavy metal toxicity to Xenophus embryos by magnesium ions.
Explore the source record for details and available documents.
Impedance cardiography.
Explore the source record for details and available documents.
Human platelet MAO in drug-free and medicated schizophrenic patients.
The authors compared platelet monoamine oxidase activity in drug-free chronic and acute schizophrenic patients, medicated chronic schizophrenic patients, and normal controls. A significant decrement in MAO activity was found only in medicated chronic schizophrenic patients. The possible mechanism for this finding is discussed.
Heterogeneity of human platelets. VII. Platelet monoamine oxidase activity in normals and patients with autoimmune thrombocytopenic purpura and reactive thrombocytosis: its relationship to platelet protein density.
Explore the source record for details and available documents.
Super salesmen make EPSDT work in Pennsylvania.
Explore the source record for details and available documents.
Less paperwork and more communication aids South Carolina's EPSDT program.
Explore the source record for details and available documents.
A study of the kinetics of the muscarinic effect on phosphatidylinositol and phosphatidic acid metabolism in rat brain synaptosomes.
The uptake of [32P]phosphate into phosphatidylinositol and phosphatidate was measured in synaptosomes incubated in Krebs-Ringer bicarbonate buffer, pH7.4. The apparent dissociation constants for acetylcholine and carbamoylcholine was estimated from the increase in 32P uptake caused by these agents. These apparent constants were similar for both phosphatidylinositol and phosphatidate and were 2.7 +/- 0.5 MICROmeter for acetylcholine and 12 +/- 2 micrometer for carbamoylcholine when Ca2+ concentration was 0.75 mM. Under the same conditions the inhibition of the carbamoylcholine-induced increase in 32P uptake, caused by atropine, is consistent with atropine being a competitive inhibitor, with an apparent inhibition constant of 0.35 +/- 0.05 micrometer. The apparent constants were dependent on the Ca2+ concentration, and were greater in 2.54 mM-Ca2+. The former values for the kinetic constants are similar to the muscarinic-receptor dissociation constant, which indicates that the binding of the agonist to the receptor may be rate-limiting in this series of reactions when the Ca2+ concentration is 0.75 mM.
Alkaloids of Vinca rosea L. (Catharanthus roseus G. Don). 38. 4'-Dehydrated derivatives.
A series of 4'-dehydrated derivatives of various dimeric Vinca alkaloids has been synthesized to further define the structure-activity relationships of Vinca alkaloids with onolytic potency. The concentrated sulfuric acid dehydration in most cases gave mixtures of the 3',4'-and two isomeric 4',20'-alkenes, which were isolated and characterized primarily by proton and 13C NMR. Compound tested for antitumor activity include the three dehydro isomers of 4'-deacetylvinblastine, 4-deacetylvincristine, and 4-deacetylvinblastine-23-amide and some4'-dehydrated derivatives epimeric at C-18'. Generally, the decrease in toxicity imparted by the new double bond was accompained by a decrease in potency. An exception was 3',4'-dehydro-4-deacetylvincristine, which showed a decrease in toxicity and increase in potency against at least one tumor in which vincristine itself has little effect.