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Biomedical subjects

S Shuster

Publications and source records attributed to S Shuster.

At least 253 records · Page 14Linked to original sources
PubMed1977

Effect of sex and age at gonadectomy on the sebaceous response to progesterone.

The effect of progesterone on the rate of sebum secretion was examined in intact and gonadectomized rats. In intact, adult, male rats, progesterone administered for 3 weeks decreased sebum secretion; after castration of adult males, progesterone increased sebum secretion and an even greater response occurred in male castrated at 21 days of age. In intact, adult, female rats progesterone slightly increased sebum production. As in the male, the response was affected by the time of gonadectomy, a greater response occurring after spaying at 21 days compared with 10 weeks of age. Thus, the response to progesterone in the adult rat differs in intact males and females and is affected by changes in the endocrine environment induced by gonadectomy, especially near the time of puberty.

Age Factors↗
PubMed1976

Immunoreactive beta-melanocyte-stimulating hormone in cerebrospinal fluid.

Immunoreactive beta-melanocyte-stimulating hormone (beta-M.S.H.) has been detected in cerebrospinal fluid (C.S.F.). Samples of C.S.F. obtained from 30 patients gave a mean (+/- S.E.M.) concentration of 60.1 +/- 8.0 ng/1 of beta-M.S.H. This is significantly greater than the mean (+/- S.E.M.) plasma concentration of 16.1 +/- 1.1 ng/1 for normal adults. There was no relationship to disease state and no correlation was found between C.S.F. concentration of beta-M.S.H. and C.S.F. total protein. This finding of high concentrations of beta-M.S.H. in the C.S.F. therefore appears to be physiological and suggests that immunoreactive beta-M.S.H. may have an action on the central nervous system in man.

Antigens↗
PubMed1976

Biological purpose of acne.

It is argued that the close endocrine control of human sebaceous glands and the likely effects of acne on selection indicate that both gland and disease have persisted because they are biologically useful. Two possibilities are proposed: sebum may provide precursor substrates for metabolism and synthesis by the epidermis of compounds of both local and systemic importance; and the adjuvent properties of corynebacteria which colonise the active sebaceous glands of acne may facilitate certain general immunological membrane.

Acne Vulgaris↗
PubMed1976

Role of the kidney in regulating plasma immunoreactive beta-melanocyte-stimulating hormone.

An analysis of the factors that influence the increase in plasma immunoreactive beta-melanocyte-stimulating hormone (beta-MSH) concentration in chronic renal failure showed that: (a) the increase correlated with the increase in serum creatinine concentrations; (b) beta-MSH was not cleared from the plasma by haemodialysis; (c) beta-MSH concentrations increased with length of time on dialysis and increased further after bilateral nephrectomy but there was no further increase with time; (d) beta-MSH levels decreased to normal after renal transplantation; and (e) beta-MSH was excreted in urine only when plasma levels rose to well above those of chronic renal failure (in Nelson's syndrome). These findings suggest that the kidney regulated plasma beta-MSH by a non-excretory mechanism and is the major site of beta-MSH metabolism.

Antibodies↗
PubMed1976

Thyroid disease and sebaceous function.

Sebum excretion rates (SER) were measured before and after treatment in patients with hypothyroidism and thyrotoxicosis. The mean SER in the former was significantly less than that in normal controls but there was no correlation between SER and the severity of the disease as indicated by serum thyroid-stimulating hormone levels. After treatment with L-thyroxine the SER increased but remained subnormal. By contrast the SER was not increased in patients with thyrotoxicosis and it was unaffected by treatment. The human sebaceous gland seems to respond to thyroid hormone mainly in the hypothyroid range.

Adolescent↗
PubMed1976

The effect of alpha-melanocyte stimulating hormone (alpha-msh) on the metabolism of biogenic amines in the rat brain.

The effect of the chronic administration of alpha-MSH on the incorporation of tritiated tyrosine into noradrenalin and dopamine and of tritiated tryptophan into serotonin was studied in different regions of the rat brain. Alpha-MSH increased the incorporation of tritiated trytophan into serotonin in the cortex and slightly decreased that of tryosine into the dopamine in the hypothalamus. As the brain concentration of serotonin was unchanged in the animals treated with alpha-MSH, it is suggested that some of the changes in behavior, which other investigators have found following the administration of peptides containing the same sequence of amino acids to that found in MSH, could be associated with an increased turnover of cortical serotonin.

Animals↗
PubMed1976

Sebaceous lipogenesis in human skin. Variability with age and with severity of acne.

Lipogenesis from [14C] glucose was measured in skin biopsies from the shoulder-blade region of forty-two male subjects. In the acne age range, dermal lipogenesis showed an upward trend with increasing severity of acne; a similar trend was found in forehead sebum excretion rate, but no correlation was obvious between dermal lipogenesis (back) and sebum secretion rate (forehead) in the same subject. In older subjects, dermal lipogenesis was significantly increased in those with a past history of severe acne. At high rates of dermal lipogenesis there was a small but significant increase in wax ester labelling relative to triglyceride and squalene. No increase was found in squalene labelling relative to other lipids, either with increasing lipogenic rate or in severe acne. Dermal and epidermal lipogenesis rates showed no correlation with age. In dermis, however, there was a decrease in wax ester labelling relative to triglyceride, and a marked decrease in squalene labelling relative to both triglyceride and wax esters, with increasing age.

Acne Vulgaris↗
PubMed1976

The cell proliferation kinetics of psoriasis examined by three in vivo techniques.

The cell proliferation kinetics of the germinative compartment in psoriasis have been re-investigated with tritiated thymidine and vincristine techniques. The mean cell cycle durations calculated from an extended fraction of labelled mitoses experiment were Tc=56 h, t1=43 h, ts=7-7 h and t2=5-6 h. Combination of the results of the FLM experiment with the experimental labelling index and the experimental birth rate suggests a growth fraction of unity and an exponential age distribution for the germinative population. An exponential age distribution is supported by the presence of several layers of germinative cells and the direction of the mitotic axes during cell division.

Adult↗