摘要:

1. A high incidence of abnormalities of the maxillary incisor was found amongst aged mice in a colony of C57BL/Icrf mice. The anomalies were virtually absent in young adult and middle-aged mice of the colony.2.The frequency distrubution of affected animals in the samples of the aged population suggested a progressive increase in the frequency of defects after 24 months. 3. Hair impaction in the gingival tissues of both maxillary and mandibular incisors was found in mice of all ages. 4. Serial observations on a group of aged mice revealed that unilateral abnormalities of the incisor had no immediate deliterious effect on the mouse while bilateral anomalies tended to result in rapid loss of weight and death. 5. Investigations on the heads of a group of aged mice dying from natural causes demonstrated that the molar teeth are normal except for severe wear. 6. Radiological and histological studies of the same group of mice revealed many pathological features including the presence of secondary incisors, dens in dente and odontome-like structures. Loose hairs were commonly present in the gingival sulci and also deeply-embedded in the periodontal ligament of both normal and abnormal incisors

ISSN:0304-324X    

DOI:10.1159/000211833

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

Autoradiographic data of 3H-proline turnover by mouse skeletal cell compartments of different age were subjected to graphical analysis for the further characterization of the effects of age on skeletal cell metabolic behavior. Periosteal osteoblasts showed early significant age changes by 26 weeks of age, paralleling the previously reported histocytomorphological changes. Age changes appeared to be nonsignificant in metaphyseal osteoblasts at 52 weeks of age, however, the total turnover of 3H-proline was adjusted to the reduced functional demands associated with trabecular remodeling and closure of the epiphyseal plate. The dramatic changes observed in 3H-proline uptake and turnover of the epiphyseal plate cartilage cells coincided with the closure of the plate and termination of matrix formation. In addition, highly significant age changes occurred in response to the cessation of functional demands. Residual articular cartilage cells appeared to be capable of retaining their viability, staving off early age changes, thus insuring a reasonably healthy joint function in older animals. The effects of age on the skeletal cell utilization of 3H-proline were best expressed as a series of steady-state events of diminishing activity. The time table for significant age changes varied in different cell compartments and also in similar cell types located at different anatomical sites. Modulation of the time table for skeletal cell aging appeared to be dictated by functional demands.

ISSN:0304-324X    

DOI:10.1159/000211834

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The influence of aging on the stability of mRNA has been investigated in Drosophila by measuring the incorporation of 3H-leucine into thorax and ovary proteins after injection of actinomycin-D. In the ovary, there is an identical decrease at any age in the rate of protein synthesis following injection of the drug. Thus, no age-related difference can be found in the stability of the corresponding mRNA templates, whose half-life is about 8–9 h. In the thorax, however, actinomycin-D significantly stimulates 3H-leucine incorporation in young flies, but slightly inhibits protein synthesis in old individuals. Thus, aging involves a progressive loss of stability of the mRNA templates responsible for the synthesis of thorax proteins. Flies of various ages have also been pulse-labeled with 3H-leucine in order to measure the rate of protein synthesis. Incorporation into ovary proteins exhibits, in function of age, a pattern of variation which follows the egg-laying curve, with a maximum early in adult life. Incorporation into thorax proteins, on the other hand, steadily increases with age. Similarly, the decrease of radioactivity in thorax proteins following a single injection of 3H-leucine is more rapid in old individual

ISSN:0304-324X    

DOI:10.1159/000211835

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

Comparison between young and old rats confirmed that, in old age, the phosphocreatine (PC) of muscle decreases. Parallel to this, the adenine nucleotides of muscle were estimated and it was found that the restoration of ade nosine triphosphate (ATP) is diminished in old age. The relationship Q = ATP/ADP (adenosine diphosphate) decreases from 6.7 to 2.2. The role of the carbohydrate metabolism for the recovery of muscle was controlled by glycogen estimations in muscle and liver. In both, the glycogen content during rest is diminished in old age. Succinate dehydrogenase (SDH) activity decreases in muscle of old animals. Aldolase (ALD) activity does not change significantly. This confirms the conclusion that, in old age, the aerobic part of the carbohydrate metabolism, i.e. the recovery process of muscle, is diminished.

ISSN:0304-324X    

DOI:10.1159/000211836

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

On isolated human adipose tissue of 80 lean und 50 obese subjects of 18 to 72 years of age the mean fat cell diameter and the in vitro release of glycerol and free fatty acids were determined. In obese patients mean and basal re-esterification rate were increased, whereas the norepinephrine-induced stimulation of lipolysis was reduced. The basal lipolysis of normal-weight subjects was independent of age, however, the stimulation of lipolysis induced by 0.1 μgnorepinephrine per ml was negatively correlated to the age of the patients. Basal and stimulated lipolysis was independent of age in obese subjects

ISSN:0304-324X    

DOI:10.1159/000211837

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The adjuvant activity of Bordetella pertussis was investigated, both at the cellular and humoral levels, when the bacterial adjuvant was administered together with 4 × 108 sheep erythrocytes in young adult (3 months old) and senile (22 months old) female mice. When compared with young adult animals, the spleens of aged mice contained significantly reduced numbers of direct and indirect plaque-forming cells and the serum hemolysin titres were found to be markedly lowered. After the simultaneous injection of B. pertussis cells into young adult mice, significant splenomegaly was demonstrable, this being associated with an accelerated and prolonged increase in the number of plaque-forming cells per 106 spleen cells. The additional injection of pertussis organisms into aged mice did not lead to splenomegaly, but to a significantly increased primary immune response, detectable both at the cellular and humoral levels

ISSN:0304-324X    

DOI:10.1159/000211838

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000211839

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000211840

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000211841

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000211842

出版商:S. Karger AG    

年代:1971

数据来源: Karger