摘要:

The leukemia-prone C58 strain of mouse was examined for age-related changes in cellular immune function. Proliferative responses of lymphocytes to autologous and allogeneic stimulator cells [autologous mixed lymphocyte response (AMLR) and mixed lymphocyte response (MLR), respectively] and to mitogens were tested both prior to and around the usual age of disease onset which occurs at 7–8 months. Leukemia in these animals was defined by elevated peripheral blood and splenic white blood cell counts. The AMLR declined > 30% by 6–7 months of age and was virtually absent by 8 months of age even in animals that were not overtly leukemic. The MLR declined precipitously ( > 95%) at 9 months of age. Both declines occurred at a younger age in C58 mice than in nonleukemic strains. Mixing experiments with cells from young and old animals indicate a defect in the Ly 1+23––, L3T4+ responding T cells. No evidence indicating a role for suppressor cell activity in this decline of cell-mediated immunity could be found. Deficiencies in cytokine (IL-2 and IL-1) production were not observed except in the oldest mice tested. Around the usual time of disease onset, splenic natural killer (NK) cell activity declines sharply even in nonleukemic mice. Cell-mixing experiments showed no evidence of suppressor cell activity by spleen cells from older mice, leukemic or nonleukemic, on the NK cell activity of young adult animals. Interferon α β treatment enhanced the NK activity of cells from old mice but did not restore the level of activity seen in young mice. Evidence has therefore been found for a premature decline in cellular immune function in two responses with proposed immunoregulatory roles, the AMLR and NK cell activity. It is possible that their decline could play a predisposing role in the onset of this retro viral leukemia or that these cell populations may be the target of the r

ISSN:0304-324X    

DOI:10.1159/000212959

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The age-related changes in the number and density of optic nerve fibres were studied in 3-month-old (young), 12-month-old (adult), 20-month-old (senescent) and 30-month-old (aged) male Wistar rats. Two-micrometer-thick resin-embedded transverse sections of the optic nerve of animals of the different age groups were stained with toluidine blue and examined under a light microscope at low (× 5) and high (× 500) magnification. The optic nerve cross-sectional area and the number of nerve fibres with diameters shorter or longer than 1 μm were assessed by means of computerized image analysis. Optic nerve cross-sectional area is constant in young and adult rats, but is increased in senescence. The number of optic nerve fibres with a diameter less than 1 μm is decreased by about 18 and 12% in 20-month-old rats versus 3- and 12-month-old rats, respectively. The number of these nerve fibres is decreased by about 43, 39 and 30% in 30-month-old rats versus 3-, 12- and 20-month-old animals, respectively. In contrast no age-dependent changes were observed in nerve fibres with diameters greater than 1 μm. The present data suggest that age-related impairment of nerve cell population described by other authors in rat retina and visual cortex occurs also at the level of the optic n

ISSN:0304-324X    

DOI:10.1159/000212960

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The relative growth inhibitory effects of 2-deoxyglucose and antimycin A were monitored at five stages during the life-span in vitro of human diploid fibroblasts. A marked age-dependent response was observed with 2-deoxyglucose but not with antimycin A. The results confirm an increase in the rate of glycolysis with ageing, which appears to be independent of cellular mitochondrial respiratory chain capacity. This may be associated with reduced utilization of the hexose monophosphate shunt and a consequent decline in the availability of ribose moieties for nucleic acid biosynthesis.

ISSN:0304-324X    

DOI:10.1159/000212961

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Sera from 40 elderly individuals ranging in age from 60 to 94 years were tested for the presence of antibodies to varicella-zoster virus (VZV)-specific proteins. Sodium do-decylsulfate polyacrylamide gel electrophoresis analysis of lysates of VZV-infected BSC-1 cells labeled with either [35S]methionine or [3H]mannose and immunoprecipitated with human sera revealed the variable presence of VZV-specifïc antibodies to four VZV glyco-proteins (gpI, gpII gpIII, and gpIV), and three nonglycosylated proteins (155, 140, 32 kilo-daltons, kDa). The predominant antibody response in the sera from the elderly was to VZV gpII and the 155-kDa species. In addition, some sera from elderly individuals without an identifiable history of varicella or zoster contained antibodies to VZV proteins, suggesting a possible subclinical infection in these patients. Finally a history of zoster in the elderly was significantly correlated (p = 0.02) with the presence of antibody to gpIV

ISSN:0304-324X    

DOI:10.1159/000212962

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The effects of ageing and of 6 months of Hydergine® treatment on lipofuscin deposition within the cytoplasm of pyramidal neurons of rat prefrontal cortex, hippocampus (fields CA1 and CA3) and of Purkinje neurons were assessed microfluorimetrically. No lipofuscin autofluorescence was detected in the nerve cell populations of 3-month-old rats, but lipopigment had accumulated in nerve cell bodies of 16-month-old animals and increased significantly thereafter in rats of 22 months of age. In 22-month-old rats, Hydergine administration (0.6 and 1 mg/kg p.o.) started at 16 months caused a significant dose-related decrease in lipofuscin accumulation within the cytoplasm of the various kinds of nerve cells examined

ISSN:0304-324X    

DOI:10.1159/000212963

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The effect of aging on vasopressin (VP) clearance was studied in male Fischer 344 rats 2 (young), 12 (adult) and 30 (old) months of age using in situ liver perfusion technique. The liver was perfused with Krebs-Henseleit bicarbonate buffer containing 1% bovine serum albumin and VP (2 ng/ml), at a constant temperature of 37 ± 0.5°C and a flow rate of 150 ml/h for 120 min. Expressed per whole liver and per gram tissue, VP declined exponentially over the studied period fitting well to the curve y = bekx (p = 0.0001) in all three groups. The analysis of covariance revealed the slope of the VP decay curve to be steepest in old rats, significantly different from that of young (p = 0.0001 expressed per whole liver or per gram tissue) and adult (p = 0.0001 and p = 0.001, expressed per whole liver and per gram tissue, respectively) rats. This suggests that, at least in male Fischer 344 rats, the hepatic clearance of VP was fastest in old rat

ISSN:0304-324X    

DOI:10.1159/000212964

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Age changes in subperiosteal areas of human bones are described in 56 subjects of both sexes aged 18–96 years, using microradiographic and histological analysis of thick undecalcified sections from the midshaft of the femur, the tibia, the third metacarpal bone and the third rib. Till the age of 39, most areas of the subperiosteal bone consist of circumferential fundamental lamellae. From the age of 48, certain areas of the subperiosteal bone appear hypercalcified, while in others mineral precipitations occur in the inner layer of the periosteum close to the bone cortex, involving the deep periosteal fibers. These periosteal calcifications should partially account for the increase in transverse diameter of bones throughout adult lif

ISSN:0304-324X    

DOI:10.1159/000212965

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

We studied the correlation between the in vitro lymphocyte proliferative response and some early parameters of lymphocyte activation in aged people. While a consistent number of elderly subjects showed significantly decreased proliferative responses to mitogen stimulation, interleukin-1 (IL-1) production and IL-2 receptor/DR antigen expression were comparable to those of young controls. The reduction in IL-2 production observed in some aged donors did not correlate with the decreased proliferative activity in response to mitogen. Moreover, addition to the cultures of recombinant IL-2 was not capable of restoring the proliferative response to normal levels. These data on the whole seem to argue against a primary involvement in age-associated lymphocyte hyporesponsiveness of an alteration in the early phases of lymphocyte activation engaging the complex lymphokine/receptor network.

ISSN:0304-324X    

DOI:10.1159/000212966

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Skin ageing was studied with a noninvasive method: indentometry. We measured two rheological parameters: resistance to pressure, indentation, under the pressure of 10 g/cm2, and elastic rebound, elasticity, after the removal of the pressure. We studied three different populations: cloistered nuns, white collar and blue collar workers. We found in all populations a steady decrease in elasticity as a function of age; this effect was always steeper in females. The working women lost their elasticity more rapidly than the nuns, and the male blue collar workers lost their elasticity more rapidly than the male white collar workers. The development of indentation as a function of age is somewhat different. The white collar males showed a steady loss of resistance to pressure with age much more rapidly than their blue collar counterparts. The females showed either a biphasic change (the nuns), no change at all (the white collar workers) or a loss of resistance to pressure (the blue collar workers). These results show that professional as well as social factors may influence skin ageing.

ISSN:0304-324X    

DOI:10.1159/000212967

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

We quantitated the skin elastic fibers of the papillary and reticular dermis using specific staining procedure followed by automated computerized image analysis. Fifty skin biopsies of patients consulting for cardiovascular risk factors were studied. The following parameters were estimated: surface area (% of total surface), length, and number of fibers as a function of age. The evaluation of the skin elastic fiber system showed no significant trend with age in the number of elastic fibers per unit area in the superficial or deep dermis. We found, however, a continuous increase with age in the relative surface area, and the length of the elastic fiber system. These results can best be interpreted as a continuous apposition of elastic-type material to the preexisting fibers by skin fibroblasts. This material may well be of a different composition than young elastin, for instance enriched in structural glycoproteins (microfibrils), lipids and calcium as found in the elastic fibers of aorta and lung. Such quantitative modifications may explain the decrease in skin elasticity, and the continuous increase in stained fibers.

ISSN:0304-324X    

DOI:10.1159/000212969

出版商:S. Karger AG    

年代:1988

数据来源: Karger