ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1982.tb00424.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Descriptive biochemical characteristics of aqueous extracts from young adult and aged male and female rat sublingual glands, have been examined. No change in gland protein or DNA content was observed with increased age. The concentrations of sialic acids and neutral sugars, in gland extracts, from aged rats of both sexes, were increased 25–50% compared to their young adult counterparts. No consistent difference in any individual protein species, resolved by 3.75% and 10% acrylamide gel/SDS electrophoresis, was foun

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1982.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The utilization of3H‐uridine (3H‐U) was used to assess age related changes in RNA biosynthesis by connective tissue cells of the periodontal ligament. One hundred forty‐four BNL mice from 5 to 78 weeks old were injected with 5μ Ci/gm body weight of3H‐U and killed from 15 min to 30 days later. Autoradiographs were prepared from 5μm thick, decalcified, sagittal sections of the maxillae. Labeled periodontal connective tissue cells were grain‐counted (1) below epithelial attachment, (2) below crevicular epithelium, (3) above alveolar crest, and (4) at the alveolar crest.3H‐U incorporation was apparent at all time periods (15 min to 30 days). Nuclear labeling achieved peak values 1–4 hours after3H‐U injection. Cytoplasmic values were maximum at 1–2 days. Nuclear and cytoplasmic counts were similar at 8–16 hours. From 5 to 52 weeks of age, peak values were progressively reduced, curves were broadened and shifted towards later time periods. This age decline in the rate and magnitude of incorporation of3H‐U reflects changes in the cellular needs for RNA and protein synthesis necessary for matrix production and cellular maintenance. Some age changes were seen at 26 weeks of age. In the oldest animals (78 weeks), there appeared to be an arrest in the age‐decline in3H‐U utilization. This was probably associated with the inflammatory changes reported in the periodon

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1982.tb00426.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Periodontitis is a chronic disease of humans and animals which becomes more prevalent and severe with increasing age. The prevalent interpretation of the strong correlation between periodontal disease and age is that age merely occurs simultaneously during the extended time that irreversible loss of tooth support results from the accumulative effects of plaque and calculus. In both animals and humans, changes in the periodontium occur with age and are similar to those seen in the same type of tissues elsewhere in the body. To date, it is not clear to what extent these aging changes affect the response of the periodontium to local irritants. At all ages, periodontitis is more severe in mouths with abundant debris and calculus. However, even when these accumulations are minimal, periodontitis becomes more severe with age. Yet, not all elderly, and especially not all teeth in the elderly, suffer from destructive periodontal disease. The periodontium of old animals and humans retains the ability to respond adequately to changes in occlusal forces and to wounding, but the response is delayed in onset and duration. As well, the elderly are likely to suffer from other chronic diseases which may affect the periodontium and its therapy.

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1982.tb00427.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1982.tb00428.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

One of the objectives of gerontological research is to achieve, reproducibly and at will, a verifiable discrepancy between the chronological and biological age of organisms. To accomplish this, the experimenter must be in a position to measure biological age independently. In theory, this can be done in three ways: by actuarial analysis of large populations, assessment of overall morbidity, or observation of chronic degenerative changes that can be actually measured or graded according to a scale. Of these three approaches, only the last appears to be promising in experimental research. However, not all progressive degenerative changes represent practically useful parameters of biological age. Criteria for their evaluation are presented, and their theoretical prerequisites as well as concrete applications are discussed. In a more general way, one has to be aware that biological age is a statistical entity. It cannot be directly observed but only inferred from quantifiable epiphenomena, and is, as such, not measurable like temperature or weight.

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1982.tb00429.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY