摘要:

The survival of ebony, yellow, ebony-yellow double mutant and their wild type was studied on two types of media. All genotypes showed greater survival in the presence of 10% ethanol (E) than on the control agar medium (C), with wild type showing greatest and the double mutant ebony-yellow least response. This increase in survival on E was negatively dependent on that on C. The relationship between alcohol dehydrogenase (ADH) activity and survival appeared to be negative on E. On C it was either slightly positive for males or constant for females. The degree of survival increase standardized in relation to survival on C [(E–C)/C] was more dependet on the level of ADH activity for the males (r = ––0.98; p > 0.05) than for the females (r = ––0.38; NS). In the complex interaction between morphogenes, ADH activity and survival, morphogenes increased the ADH activity and decreased survival on E.

ISSN:0304-324X    

DOI:10.1159/000212854

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The effect of elastase on dermal elastic fibers from three age groups (children, young and old adults) has been investigated using ultrathin sections embedded in Epon. There were significant differences in the effect of elastase among the age groups; younger elastin was more rapidly digested by elastase than older elastin. In children and young adults, digested areas by elastase were first recognized as tiny round holes scattered in the amorphous material of the elastic fiber, extending to the large part of the fiber except for micro-fibrils. In old adults, digested areas were limited to the only small part of the elastic fiber.

ISSN:0304-324X    

DOI:10.1159/000212855

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Despite the considerable amount of data published during the last 30 years concerning the hematological status of the aged, practitioners are still confronted with the problem of ‘normal’ or ‘physiological’ values in these subjects. Indeed, significantly different values are presented in the literature as normal for the aged, apparently depending on the various types of populations studied. Criteria used to define the subjects as ‘normal’ could be the main factor responsible for this discrepancy. Based on this hypothesis, we determined the values of usual blood cell parameters in two groups of apparently healthy subjects of over 75 years of age. Subjects of group A (16 men and 13 women) were selected according to the stringent criteria of the Senieur protocol and subjects of group B (15 men and 20 women) were recruited using ‘conventional’ admission criteria. For both groups, sex-matched young controls aged 20–29 years were tested in parallel. No clinically significant alteration was observed in group A, whereas more pronounced differences were found in group B. Our results confirm the necessity for stringent selection criteria in biological investigations in gerontology. Moreover, they demonstrate that blood cell parameters are not altered in the aged, provided that the latter are

ISSN:0304-324X    

DOI:10.1159/000212856

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Aldosterone production by suspensions of adrenal glomerulosa cells obtained from young and old cows was measured. Basal steroidogenesis was lower in cells from old cows, as were the responses to angiotensin II (AII), potassium, ACTH and dibutyryl cyclic AMP. Receptors for All and aldosterone production from added progesterone were the same in old and young cells. Synthesis of pregnenolone from endogenous precursor, the ‘early pathway’ of aldosteronogenesis, was lower in old cells than in young. All-stimulated incorporation of 32P into phosphatidylinositol and the change in 45Ca2+ flux induced by All were diminished in old cells. Overall protein synthesis, measured by 3H leucine incorporation, was lower in old cells than young, but was not affected by All in either. Diminished responsiveness of adrenal glomerulosa cells from old animals results from a change in postreceptor events that affect the early pathway of aldosteronogene

ISSN:0304-324X    

DOI:10.1159/000212857

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Although earlier reports in the literature suggested degenerative changes in the senescent hypothalamo-neurohypophyseal system (HNS), recent investigation showed hy-peractivity of this system in the old Wistar (WAG/Rij) rat. In the brain, changes were found in those sites of extrahypothalamic vasopressin (VP) fiber termination that are testosterone-dependent. In the present study, further evaluation of these changes was performed in male Brown-Norway (BN/BiRij) rats. Immunocytochemical staining of VP binding sites in renal tubuli of the senescent, 33-month-old rats was occasional, and could only slightly be enhanced up to weak staining by in vitro preincubation with the peptide, in contrast to the intense staining observed in young, 3-month-old rats. Although VP plasma levels of young and old rats did not differ significantly and no change in either urine or plasma osmolality was observed, urinary VP concentration and 24-hour urinary VP excretion were significantly increased in senescent rats. The activation of the hypothalamo-neurohypophyseal system (HNS) in the senescent rat seems thus to compensate for a decreased responsiveness to VP in the aged kidney. Testicular weight in the senescent animals declined by 40% and a highly significant decrease of 80–90% was observed in total and free testosterone plasma levels. Consequently, changes in peripheral organs in senescent rats may well underly the changes observed in the brain of these animal

ISSN:0304-324X    

DOI:10.1159/000212858

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Elderly hospitalized patients frequently do not mount a vigorous febrile response. This diminished response could be due to the combined effects of age and protein malnutrition, a common problem in the elderly. We studied the effect of mild protein deprivation on the febrile response to interleukin–1 (IL–1) and endotoxin in young, middle-aged, and elderly Fischer rats. In each age group, rats received either a standard (23% casein) or low protein (8% casein) diet for 5 weeks (young rats) or 8 weeks (middle-aged and elderly rats). Each rat received an intraperitoneal injection of IL–1, 10 μg/kg endotoxin, or 100 μg/kg endotoxin and temperatures were measured over 6 h by implanted biotelemetry devices. Protein deprivation decreased the febrile response to IL–1 in all age groups and to endotoxin only in the young and middle-aged rats. Increasing age along did not decrease the febrile response to either pyrogen. Increasing age and protein deprivation did not have an additive effect in decreasing the febrile response to IL–1 o

ISSN:0304-324X    

DOI:10.1159/000212859

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Results of a study on bone marrow (BM) cytology and cellularity, BM granulo-cytic-macrophage colony formation (GM-CFU-C), peripheral blood (PB) colony stimulating factor (CSF) and serum lysozyme activity in 20 elderly people aged from 64 to 89 are presented. Besides slight iron deficiency anemia, no hematological abnormality was detected. No change in PB and BM differential counts was found as compared to those obtained for normal adults. The BM cellularity and colony incidence were assessed using aliquots of the same specimen. GM-CFU-C frequency ranged from 15 to 156 (average 67.5) per 2 × 105 BM cells seeded. The largest number of colonies was observed in hypocellular BM samples (p < 0.002). The level of serum lysozyme activity for the entire group was significantly higher than that obtained in healthy persons up to the age of 60 (p < 0.001). The overall results support the notion that in old age, increased proliferation of committed granulopoietic stem cells in hypoplastic areas of the BM, assure normal numbers of mature blood cells in the periphery

ISSN:0304-324X    

DOI:10.1159/000212860

出版商:S. Karger AG    

年代:1987

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212861

出版商:S. Karger AG    

年代:1987

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212862

出版商:S. Karger AG    

年代:1987

数据来源: Karger