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Biomedical subjects

A Reinberg

Publications and source records attributed to A Reinberg.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Circadian rhythms of adenosine deaminase activity in human erythrocytes: a transverse study on young, elderly and senile demented subjects.

Adenosine deaminase activity (ADA) was determined around the clock in human plasma from different groups of subjects: presumably clinically healthy women in Minneapolis, USA; healthy medical students, healthy elderly men and women, and mentally ill patients in Paris, France. In addition to analyses of variance, circadian characteristics were estimated individually and summarized by population-mean cosinor for each group. Technical and sampling considerations are documented: the individualized assessment of a circadian rhythm in adenosine deaminase is feasible in 8 out of 11 series from clinically healthy women covering 24h at 20-min intervals. A circadian population rhythm could be determined for the elderly men and women (p less than 0.05) and tentatively (p = 0.053) for the senile demented patients. A difference in circadian group rhythm characteristics found between the healthy elderly subjects and patients with senile dementia deserves further exploration.

Adenosine Deaminase↗
PubMedDate not supplied

Desynchronization of the oral temperature circadian rhythm and intolerance to shift work.

The present study tested the hypothesis that subjects with a good tolerance to shift work maintain the circadian period tau of their temperature rhythm equal to 24 h, while tau may differ from 24 h when subjects exhibit one or several clinical signs of intolerance. These latter are mainly: persisting sleep disturbance, persisting fatigue, changes in mood and behaviour, and digestive troubles, from gastritis to overt peptic ulcer. These symptoms were used here to classify the subjects studied. Medications, including all types of sleeping pills, are ineffective. As was the case in the present study, some subjects may tolerate shift work for 35 yr, reaching 57 yr of age without complaint, while others, after several months or many years, quite rapidly (within 6 months) develop symptoms of intolerance.

Adult↗
PubMedDate not supplied

Circadian changes of drug disposition in man.

Circadian (approximately equal to 24 hours) and other endogenous biological rhythms, detectable at all levels of organisation, constitute a temporal structure in all animal species, including man. Circadian, circannual, and other rhythmic changes in biological susceptibility and response of organisms to a large variety of physical and chemical agents, including medications and foods, are rather common phenomena. A better understanding of periodic and thus predictable changes in drug effects can be attained through consideration of three complementary concepts: the chronopharmacokinetics of a drug (rhythmic changes in its pharmacokinetics), the chronesthesy (rhythmic changes in susceptibility of target biosystems to the drug), and the chronergy (the drug-integrated overall effects). The chronopharmacokinetics of many drugs have been evaluated in man including sodium salicylate, aspirin, indomethacin, paracetamol (acetaminophen), phenacetin, amidopyrine, theophylline, digitalis, propranolol, clorazepate, hexobarbitone (hexobarbital), lithium, phenytoin (diphenylhydantoin), nortriptyline, ethanol, erythromycin, ampicillin, sulfasymazine, sulphanilamide, cisplatin (cis-diammine dichloroplatinum), d-xylose, ferrous sulphate, potassium chloride, hydrocortisone and prednisolone, among others. The roles presumably played by circadian rhythms in drug metabolising liver enzymes and kidney function are summarized, and the practical implications of chronopharmacokinetics, aiming both to improve in a quantitative manner the metabolic fate of a drug and its effectiveness, are discussed.

Adolescent↗