Search PubMed⌕ Search

Biomedical subjects

Z Deyl

Publications and source records attributed to Z Deyl.

At least 145 records · Page 8Linked to original sources
PubMed1976

Cartilage collagen in osteoarthrosis.

Pronase digestion of osteoarthrotic cartilage collagen indicated that this type of pathological collagenous structure is more susceptible to proteolytic degradation than human controls or bovine and calf articular cartilage. There were some differences between individual patients in the collagen susceptibility to pronase cleavage. Also, different zones of the same diseased femoral head exhibited varied susceptibility. It is suggested that changes in collagen stability are reflected in cartilage permeability and in this way also in alterations in the supply of nutrients.

Animals↗
PubMed1975

Ageing processes in collagens from different tissues of rats.

It has been demonstrated by solubility data, that the differences in cross-linking and degree of polymerisation in connective tissue from different organs of a single animal are much more pronounced than the increase which occurs with advancing age. Judged from the cross-linking analysis one can therefore conclude that in a single animal there are connective tissues which differ in their degree of maturity. It is therefore conceivable to suggest that the level of cross-linking should not be taken as the measure of the biological age of the animal.

Aging↗
PubMed1975

The effect of nutritional regimes upon collagen concentration and survival of rats.

It has been demonstrated that food restriction put upon animals at any stage of the individual's life, if chronic, produces a distinct increase in the lifespan. This can be effected in youth and still have a distinct effect in old age even if the food restriction is cut down and for the rest of the life the animal is allowed food ad libitum. Since the effect upon the aging of the animal is delayed on the time scale, it is obviously an effect which is stored somewhere and it is suggested that this storage occurred somewhere along the DNA-RNA pathway. Also the effect of under nutrition is not identical with that of oxidizing free radical blocking agents and therefore it is concluded that the food deprivation does not minimize the attack of the free radicals on the long chain macromolecules and as a matter of fact it seems that the proportion by which free radicals contribute to the changes in the average lifespan in undernourished and fully nourished animals is small. It has been also demonstrated that the addition of reducing agents to normal diet and to the diet of food restricted animals increases the average and maximum lifespan in both cases practically to the same extent, which supports the idea expressed before. This feeding effect has been observed in three different species of rodents and no extrapolation has been done to other types of mammals. Due to the data published on this topic and dealing with rotifers and some insects (2) it is conceivable to conclude that the effect of undernutrition is general and is not limited to the food restriction in the early stages of development only. Collagen starts to accumulate in the kidneys and liver of experimental animals roughly ten months before 90 percent of the population dies out. Tus an increase in collagen concentration can be indicative of involutional changes in the organ (and perhaps organism). These data are i- good agreement with previously published results on the relation between collagen accumulation and chronic food deprivation in rats (6). It can be also concluded that food deprivation induced in the adult, though not so effective in life prolongation as the food restriction during early development, still can increase survival in experimental animals to a high degree.

Age Factors↗
PubMed1975

[Age differences in the reactivity of the organism after administration of isoprenaline in rats (author's transl)].

To three age groups of animals 2, 6 and 12 months old isoprenaline was administered in amounts of 8 mg/kg body weight. In these rats changes in the weight of some organs after administration of isoprenaline were followed-up. In the oldest group of rats were the myocardial lesions were most severe, the authors found the slightest oedematous response of the myocardium. The oedema of their aorta, on the other hand, was most marked. The weight of the adrenals, contrary to younger groups, did not change in the course of the experiment.

Adaptation, Physiological↗