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Biomedical subjects

M Popescu

Publications and source records attributed to M Popescu.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Circadian and circannual variations of FSH, LH, testosterone, dehydroepiandrosterone-sulfate (DHEA-S) and 17-hydroxy progesterone (17 OH-Prog) in elderly men and women.

A group of 63 men and 86 women 77 +/- 8 years of age institutionalized at the Berceni Clinical Hospital, Bucharest, Romania, on a diurnally active living schedule with rest at night, eating 3 comparable but not identical meals a day, were investigated over a 2-year span in 278 profiles extending over a 24-hour span each and distributed over all our seasons. On each day of sampling six samples of blood were collected at 4-hour intervals beginning at 0800 of the first day of the study to 0400 of the next. Plasma testosterone, dehydroepiandrosteronesulfate (DHEA-S), 17-hydroxyprogesterone (17-OH Prog), FSH and LH concentrations were determined by radioimmunoassay. Statistically significant circadian rhythms were detected and quantified by population mean cosinor for the men and women of the entire group and for the age groups of 51 to 70 (I), 71 to 80 (II) and above 80 years of age (III) separately. Circannual rhythms of the circadian means were sought and evaluated by one way analysis of variance. Statistically highly significant circadian rhythms were found in plasma testosterone, 17-OH Prog and DHEA-S, concentrations in men and women of all three age groups with a phase advance of over 2 hours in DHEA-S with advancing age. Circannual cycles were found for plasma testosterone concentration and for DHEA-S in men and women, with a likely phase difference between men and women in testosterone. In LH a circadian rhythm was found in the women and in FSH in men only and a circannual variation in LH only in men.

17-alpha-Hydroxyprogesterone↗
PubMedDate not supplied

Circadian rhythm of beta-endorphin in the plasma of clinically healthy subjects and in patients with adrenocortical disorders.

Immunoreactive beta-endorphin was determined in the plasma of 37 elderly subjects (73 +/- 7 years of age), in 3 young or young adult subjects without adrenal disease, in 4 women with clinical adrenogenital syndrome, in 1 man with Cushing's disease. Immunoreactive beta-endorphin in plasma was measured by radioimmunoassay in six samples of each subject collected at 4-hour intervals over a 24-hour span. The observation of a circadian rhythm in circulating immunoreactive beta-endorphin with highest values during the late night and early morning hours is extended to elderly subjects in the 8th decade. The beta-endorphin plasma concentrations in the few clinically healthy young adult subjects studied fell within the same range. The circadian variation of the group of elderly subjects was used as reference in the clinical evaluation of plasma beta-endorphin concentrations in patients with pituitary-adrenocortical disorders. The need for circadian rhythm qualified reference values is shown by the observation of the circadian variations of circulating immunoreactive beta-endorphins in the patients with adrenogenital syndrome and Cushing's disease in whom abnormalities in the concentration of circulating beta-endorphin were found at certain circadian stages but not at others.

Adolescent↗
PubMedDate not supplied

Cystic parathyroid cancer. Case report.

A patient hospitalized for the assessment of a "thyroid nodule" is presented. Scintigraphically the nodule was cold. Thin needle aspiration biopsy by which 50 ml of a clear fluid was drawn, proved the nodule to be of cystic nature. Phospho-calcium findings allowed the diagnosis of primary hyperparathyroidism though the patient presented no subjective complaints. Histologic examination of the tissue removed intraoperatively revealed a cystic parathyroid neoplasm.

Combined Modality Therapy↗
PubMedDate not supplied

Chronobiology of serum iron concentration in subjects of different ages at different geographic locations.

The circadian rhythm in serum iron concentration was studied in 61 elderly men (74 +/- 6 years of age) and 93 women (78 +/- 8 years of age) in Bucharest, Romania, in 81 clinically healthy boys and 103 girls (11 +/- 1.5 years of age) in Tîrgovişte, Romania, in 4 elderly men and 19 women (71 +/- 5 years of age) and in 75 young-adult men (24 +/- 11 years of age) and 52 women (24 +/- 9 years of age) in St. Paul, Minnesota, USA. Six samples were obtained from each subject around a 24-hour span. The sampling sessions in the elderly subjects in Romania and in the children extended over all four seasons. A circadian rhythm statistically verified by Cosinor analysis was evident in all groups in both locations. A statistically significant sex difference with lower circadian mean (mesor) and a lower amplitude in the women was found in the Romanian elderly subjects. The children in Romania showed no sex difference in any circadian rhythm parameters. The young adult subjects in Minnesota showed a significantly higher mesor and a phase delay in the men as compared with the women. The elderly subjects of both sexes at both geographic locations had a lower circadian mesor than the young adults and the children. In the Romanian elderly subjects also the circadian amplitude was lower, which was not the case in the Minnesotans. While the acrophase in the elderly subjects and in the children in Romania was comparable (0928 and 0932 local time resp.), the young adults in Minnesota showed in comparison to the Romanians a phase delay (1132 local time) and the elderly in Minnesota showed a phase advance (0732 local time) in comparison to all other groups. The latter finding will have to be confirmed by more extensive studies. In the elderly subjects in Romania the circadian rhythm in serum iron concentration was in phase with the circadian rhythms in total serum bilirubin and alkaline phosphatase but showed significant phase differences from the circadian rhythms in serum albumin, urea nitrogen (BUN), gammaglutamyl transferase (Gamma-GT), serum globulins, glucose, insulin and total serum proteins. The elderly subjects in Romania showed a statistically significant circadian phase delay in summer as compared to fall but showed no seasonal variation of the mesor. The children showed a circadian phase advance in fall as compared to the other seasons and a seasonal variation of their mesor with higher values in spring and summer as compared with winter and fall.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMedDate not supplied

Circannual rhythms of laboratory parameters in serum of elderly subjects. Evaluation by cosinor analysis.

A total of 189 elderly subjects 76 +/- 8 years of age were studied in 230 24-hour profiles consisting of six blood samples collected at 4 hour intervals. The sampling sessions were spread over all four seasons. The circadian means were analyzed by single cosinor analysis for the presence of circannual variations. Statistically significant circannual variations were found in men and/or in women in the serum concentrations of: albumin, total bilirubin, calcium, chloride, CPK, glucose, LDH, potassium, sodium, triglycerides, and uric acid. Only in few functions is the extent of the circannual rhythms in the variables presented here large enough to present potential diagnostic problems in today's practice of laboratory medicine. However, the seasonal variations in metabolic functions, or if endogenous in nature, circannual rhythms may be of physiologic and pathobiologic importance. There is a need to quantify certain of these rhythms as a predictable portion of variability in laboratory values, and presumably as an indicator of human health.

Adaptation, Physiological↗