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Biomedical subjects

J G Phillips

Publications and source records attributed to J G Phillips.

At least 163 records · Page 9Linked to original sources

Factors controlling growth and age involution of the rat thymus.

Thymic development and somatic growth were investigated in three strains of rat. The well established influence of sex and age on somatic growth was confirmed. It was also found that the rate of thymic growth was not influenced by the sex of the animal until four weeks of age, but thereafter, the thymus grew faster in males compared with females of the same strain. Gonadectomy had a marked effect on the thymus, resulting in a higher rate of growth than in normal animals; but a slower initial rate of involution. The maximum thymus weights attained in gonadectomized animals were found to be independent of the age at which the animals were gonadectomized or of the sex of the animal. Gonadectomy did not influence the point at which involution began. Thymic mitotic indices of gonadectomized animals were found to be higher than those of normal animals. The influence of sex hormones on somatic growth and the development of the thymus is discussed, and it is concluded that cell loss is the regulator of thumus growth and involution.

Age Factors↗

Treatment of ulnar fractures by functional bracing.

Treatment of isolated fracture of the ulna by means of functional bracing was successful in seventy-two cases. No non-unions were encountered. There was minimum deformity and loss of pronation-supination, and no loss of motion at the elbow and wrist. The average time to healing was ten weeks.

Adolescent↗

Changes in organ weights and blood parameters in ageing Brattleboro rats with hereditary diabetes insipidus.

Organ weights and blood parameters were measured in male and female Brattleboro rats with hereditary diabetes insipidus (DI) and in normal rats of the same strain, between 37 and 138 weeks old. Although differences in body weight between the homozygous DI and heterozygous normal rats accounted for differences in the weights of the heart and gonads, the weights of the spleen, liver and kidney were not solely body-weight dependent; there were significant sex and genotype differences in the mean weights of these organs. The liver, heart and gonads were the only organs showing age-dependent changes. No genotype-dependent differences were observed in the haematocrit and haemoglobin concentration, although there was a sex difference; the mean values of these parameters were higher in males. Plasma glucose concentrations were significantly lower in homozygous than in heterozygous rats; in the latter, plasma glucose concentration decreased with age. No significant changes occurred in the mean plasma concentrations of sodium or potassium with age or genotype. Total plasma lipids of heterozygous female rats showed both age- and genotype-dependent changes; this parameter reached a plateau at 90-100 weeks old, and was significantly higher in heterozygous females than in all other groups. Plasma proteins showed no age-dependent changes, but were of higher mean value in heterozygous than in homozygous rats and were greater in females than in males. Differences in blood parameters of homozygous and heterozygous Brattleboro rats are discussed in terms of differences in hormone concentrations.

Age Factors↗