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Biomedical subjects

C Bogdan

Publications and source records attributed to C Bogdan.

144 records · Page 8Linked to original sources
PubMedDate not supplied

Circadian periodicity of the results of frequently used laboratory tests in elderly subjects.

The circadian rhythms of twenty-one chemical serum parameters (albumin, alkaline phosphatase, calcium, carbon dioxide content, chloride, cholesterol, creatine phosphokinase (CPK), creatinine, glucose, glutamic-oxalacetic transaminase (GOT), gamma glutamyl transferase (Gamma--GT), lactate dehydrogenase (LDH), inorganic phosphorus, iron, potassium, total bilirubin, total protein, sodium, triglycerides, urea nitrogen, uric acid) and of urinary volume and oral temperature were studied, in October 1981, in a group of 49 elderly subjects (23 men, 73 +/- 6 years of age, and 26 women, 77 +/- 8 years of age) institutionalized at the Berceni Hospital for the aged. Statistically significant circadian rhythms as a group phenomenon were found in all functions except alkaline phosphatase, GOT, and LDH. The timing and the extent of these rhythms are presented. The circadian time structure of body chemistry appears well maintained in old age. Some circadian rhythms show a large enough amplitude to require the establishment of time qualified reference ("normal") ranges (e.g. serum iron). In most others, the circadian amplitudes are small and at present of little or no diagnostic importance. They are, however, of physiologic and pathophysiologic interest indicating an intricate time sequence of metabolic events in the human body.

Age Factors↗
PubMedDate not supplied

Cortisol circadian rhythm in 70--100-year-old subjects.

The circadian rhythms of plasma cortisol was examined in 25 persons aged between 70 and 100 years by comparison with 5 adults aged between 17 and 38 years. The blood samples were drawn at 16 hundred, 20 hundred, 00 hundred, 04 hundred and 08 hundred hrs. Cortisol was assayed by the fluorimetric method. The experimental data were analyzed by Halberg's mean-cosinor method. The results showed that the circadian rhythm in plasma cortisol changes with age. The characteristic phenomena found were the following: a tendency towards reducing the hourly quantitative differences, comparatively more marked between 90 and 100 years; anticipation of the cortisol maximum level of 08 hundred at 04 hundred hrs in the group of 71 to 80 years, and at 00 hundred hrs in some of the subjects older than 80. A normal circadian rhythm was found in 2 of the 25 cases examined. These changes imply variations of the same kind in the CRF and ACTH levels. The changes in the circadian rhythms of cortisol show that the regulation systems are also implied in the aging process. It is possible that early-morning insomnia of the aged be due to this anticipation in cortisol secretion.

Adolescent↗
PubMedDate not supplied

Circadian and circannual variations in plasma immunoreactive insulin (IRI) and C-peptide concentrations in elderly subjects.

Groups of 49-51 elderly men and women 77 +/- 8 years of age, institutionalized at the Berceni Clinical Hospital, Bucharest, Romania, were studied over a 24 hour span in spring, summer, fall and winter. All subjects followed a diurnal activity pattern with rest at night and ate three meals per day with breakfast at about 08:30, lunch at about 13:00, dinner at 18:30. The meals were similar, although not identical for all subjects during all seasons. On each day of sampling, blood was collected at four hourly intervals over a 24 hrs span. Immunoreactive insulin (IRI) and C-peptide were determined in plasma and glucose (during fall and winter only) in serum. Circadian variations of all three parameters were found and the rhythm parameters were determined statistically by cosinor analysis. The acrophases of the circadian rhythm of IRI and C-peptide were the same during all four seasons. The circadian acrophase of plasma IRI and C-peptide precedes that of serum glucose. The circadian mean concentrations of IRI and C-peptide show a circannual variation with higher values in winter and fall than in spring and summer for plasma insulin and with higher values for summer and fall than in spring for C-peptide. Sex differences in IRI and C-peptide concentrations with higher values in men are manifested during certain circadian and circannual stages but not during others.

Age Factors↗
PubMedDate not supplied

Circadian variations in plasma immunoreactive insulin (IRI) and C-peptide concentrations in adult onset (type II) diabetes mellitus.

Plasma immunoreactive insulin (IRI), C-peptide and serum glucose concentrations were determined in 19 adult onset non-insulin dependent (type II) diabetics, in one adult onset diabetic on insulin and in 20 non-diabetic subjects matched for sex, age, weight and height. The subjects lived on a schedule of diurnal activity and nocturnal rest (21:00 to 06:00) at Berceni Clinical Hospital, Bucharest, Romania and ate three meals at 08:30, 13:00 and 18:30 and a snack at 10:00 (carbohydrate content: 50 gm, 65 gm, 60 gm and 25 gm respectively). Nine of the diabetic patients were on oral hypoglycemic agents (tolbutamide or meguan), the others were controlled by diet only. Blood was sampled beginning at 08:00 at 4 hourly intervals over a 24-hour span. The circadian variations of IRI, C-peptide and serum glucose were analysed by population mean cosinor. The non-insulin dependent diabetic subjects as a group and the matched non-diabetic subjects showed under the conditions of this study circadian variations in serum glucose, plasma IRI and C-peptide which were identical in timing (acrophase) and amplitude and with the exception of the much higher serum glucose concentrations in the diabetics, not significantly different in the circadian mean concentration (or mesor). The diabetics on oral hypoglycemic agents if investigated separately showed in spite of identical serum glucose concentration a statistically significantly lower circadian mean IRI and C-peptide concentration than either non-diabetic subjects or the diabetics treated by diet only. Acrophase and relative amplitude remained unchanged. Adult onset non-insulin dependent (type II) diabetics maintained on diet only show the same circadian variations in plasma IRI and C-peptide as non-diabetic matched for sex, age, height and weight. The adult onset diabetic on insulin showed an extremely high serum glucose concentration which varied in its timing over the 24-hr span similar to the other subjects. His plasma IRI concentration was about ten times that of the non-diabetic or other diabetic subjects in this study. There was no statistically recognizable circadian variation of IRI. In contrast C-peptide was found at the same concentration as found in the other two groups and showed in all rhythm parameters an identical circadian variation. The circadian acrophase of plasma IRI and C-peptide concentrations in adult onset diabetics and the non-diabetics is the same.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMedDate not supplied

Circadian time structure of endocrine and biochemical parameters in adult onset (type II) diabetic patients.

Forty-one endocrine and biochemical serum parameters were studied over a 24-hour span with 6 samples at 4-hour intervals in 20 non-insulin dependent (Type II) diabetics and in 20 non-diabetic subjects matched for sex, age, height and weight. Circadian rhythms were verified by cosinor analysis. Group-synchronized circadian rhythms were detected in diabetic and non-diabetic subjects with no statistically significant difference in any of the rhythm parameters (rhythm adjusted mean, amplitude and acrophase) in: Aldosterone, cortisol, insulin, 17-OH progesterone, prolactin, testosterone, TSH, and in serum albumin, creatine phosphokinase (CPK), serum iron, inorganic phosphate and total protein. Statistically significant (p less than .05) circadian rhythms in both groups with a difference in some parameters between the diabetic and the non-diabetic subjects, which were verified by the Bingham Test (p less than .05) were found with a difference in the mesor in cholesterol, glucose, urea nitrogen (BUN), in the amplitude in C-peptide and in the acrophase in triglycerides, globulin and reverse T3 (rT3). Statistically significant circadian rhythms were detected as a group phenomenon for the diabetics only in progesterone, free and total T4, chloride, calcium, bilirubin and LDH and in the non-diabetic subjects only in ACTH, LH, total T3, alkaline phosphatase, uric acid and potassium. In the remainder of the functions studied, a circadian rhythm was detectable with statistical significance by cosinor analysis as a group phenomenon neither in the diabetics nor in the matched non-diabetic controls (DHEA-S, estradiol, FSH, GH, glucagon, free T3, sodium, GOT and gamma GT). In the absence of a detectable circadian rhythm as group phenomenon, the circadian mean was different between the diabetics and the non-diabetic subjects in sodium, chloride and calcium which were higher in the diabetic patients and serum LDH which was lower. In a comparison of endocrine determinations in the two groups, the circadian mean or mesor in T3 was lower in the diabetics and ACTH higher, without corresponding changes in TSH or in corticosteroids. The circadian time structure of Type II diabetic patients thus seems to be very similar to that seen in non-diabetic subjects of the same sex, age, weight and height. The minor differences found in some rhythm parameters will have to be confirmed or excluded in larger numbers of subjects. The higher circadian mean ACTH concentrations without change in steroid rhythm parameters observed in this group is interesting but will also require confirmation.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMedDate not supplied

Circadian rhythm of TSH in adult onset non-insulin dependent (type II) diabetics with altered thyroid state.

Twenty adult onset non-insulin dependent (Type II) diabetic patients and twenty non-diabetic subjects matched for sex, age, height and weight were studied. The diabetes was controlled by diet only in 10 patients and by oral hypoglycemic agents in 10. All patients were diurnally active and rested at night. Blood was sampled at 4-hour intervals over a 24-hour span (6 samples). TSH, total T3 and total T4 were determined by radioimmunoassay. The circadian rhythm in TSH was statistically significant by cosinor analysis and was comparable in all rhythm parameters in diabetics and non-diabetics. The rhythms of total T3 and T4 also seem to persist with comparable timing although the small number of subjects did not allow rhythm detection at the 5 per cent level in all groups. The circadian mean of the total T3 plasma concentration in the diabetics, however, was statistically significantly lower than the usual range of this laboratory and the total T4 was elevated but within the usual range. The changes in total T3 and T4 were most pronounced in the patients on oral hypoglycemic agents. This study indicates persistence of a circadian rhythm in TSH (and presumably also in the plasma concentrations of total T3 and T4) in non-insulin dependent diabetic patients in spite of a lowered circadian mean concentration of total T3 and a slightly but statistically significantly higher total T4 than in the matched non-diabetic subjects. The altered thyroidal state in the diabetic patients thus does not interfere with the circadian periodic secretion of TSH.

Age Factors↗
PubMedDate not supplied

Endocrine circadian time structure in the aged.

Thirteen circadian rhythms in plasma hormone levels (ACTH, aldosterone, cortisol, C-peptide, insulin, DHEA-S, estradiol, LH, prolactin, 17-OH progesterone, testosterone, T4 and TSH) were studied in April 1981 in 25 males and 25 females 57 to 91 years of age, institutionalized at the Berceni Hospital for the aged. The radioimmunoassays and the statistical rhythmometric evaluation by the cosinor procedure were done at S. Paul-Ramsey Medical Center, St. Paul, MN, USA. Circadian rhythms were found and quantified for each of these variables. Elderly subjects of both sexes thus maintain a circadian time structure of their endocrine system as a group phenomenon. In comparison with previous data from the Endocrine Rhythms Laboratory ("C. I. Parhon" Institute) and series of younger subjects studied in Minnesota (St. Paul-Ramsey Medical Center) as well as in comparison with data published from other centers, the aged seem to experience an earlier arousal of their endocrine system which may be related to certain disturbances of old age e.g. of sleep. The latter observations will have to be confirmed by additional studies which take both circadian and circannual variations in account.

Age Factors↗
PubMedDate not supplied

[Leishmaniasis: principles of the immune response and function of nitric oxide].

Leishmania are flagellated protozoa, which are transmitted to mammals by sand flies. Depending on the parasite species and the host immune system, infection with Leishmania can lead to simple self-healing ulcers (e.g., oriental sore), progressive mucocutaneous lesions, or to visceral disease involving spleen, liver and bone marrow (kala azar). The control of the parasites is critically dependent on type 1 CD4+ T helper cells, which evolve in the presence of interleukin-12 and activate the macrophages for the killing of the intracellular, amastigote Leishmania stage through the production of interferon-gamma. The killing process involves reactive oxygen and nitrogen intermediates (e.g., NO). Anti-Leishmania antibodies are generated during the infection, but do not confer protection. In this article, the main components of immune response against Leishmania and the role of nitrogen monoxide (nitric oxide, NO) in the Leishmania major mouse model will be reviewed.

Animals↗