Search PubMed⌕ Search

Biomedical subjects

V S Fang

Publications and source records attributed to V S Fang.

At least 145 records · Page 8Linked to original sources
PubMed1975

Gonadal dysfunction in uremic men. A study of the hypothalamo-pituitary-testicular axis before and after renal transplantation.

Evaluation of testicular function in 13 hemodialyzed patients revealed the following: plasma testosterone (ng/100 ml) was low (less than 300 ng/100 ml) in 6 and low normal in 7 patients; sperm counts ranged from 0 to 8 million/ml and motility from 0 to 8 per cent; testicular tissue from 2 patients showed an abnormal histologic picture ranging from hypospermatogenesis to germinal cell aplasia. Follicle-stimulating hormone (FSH, ng/ml) was normal in eight (10 to 217 ng/ml), and persistently eveated in five patients (265 to 760 ng/ml). Of the latter five patients, two were azzoospermic, one had germinal cell aplasia on postmortem examination, one had virtually no viable sperms, and the other was never able to furnish ejaculate for examination. Luteinizing hormone (LH, mg/ml) was high (more than 210 ng/ml) in five and normal in eight patients. Six patients when given clomiphene showed the normal response of increased FSH and LH release. Four of the 13 patients, when restudied 6 to 12 months later and while still on dialysis, showed further deterioration of plasma testosterone and sperm counts. Four of the patients subsequently underwent successful renal transplantation. All showed improvement in sperm counts (20 to 40 million/ml, motility 40 to 90 per cent) and plasma testosterone (440 to 850 ng/100 ml). These data suggest that both germinal cell and leydig cell functions were impaired among uremic men. These dysfunctions were not correctable by hemodialysis, but were completely reversed by renal transplantation. The high FSH among patients with azzospermia indicates a responsive pituitary. The positive response to clomiphene suggests that storage as well as release of both hypothalamic and pituitary hormones were normal. Attempts to localize a single defect at the testis failed to explain the post-transplant surge of FSH which invariably proceded improvement in spermatogenesis. It is therefore postulated that a defect in that portion of the hypothalamus involved in the receipt and/or interpretation of message might be at fault in uremia.

Adult↗
PubMed1975

Studies on human thyroxine-binding globulin (TBG). IX. Some physical, chemical, and biological properties of radioiodinated TBG and partially desialylated TBG.

Thyroxine-binding globulin (TBG) and partially desialylated or slow TBG (STBG) were purified from human serum by affinity chromatography. Purified TBG was identical to TBG present in serum by the criteria of electrophoretic mobility, affinity for thyroxine (T4), and heat-inactivation response. Purified STBG had slower electrophoretic mobility and lower affinity for T4. Both bound T4 in an equimolar ratio, were immunoprecipitable, and had similar inactivation t1/2 at 61 degrees C. TBG and STBG were iodinated by the chloramine-T-catalyzed reaction. An average of from 0.02 to 6 atoms I could be incorporated per molecule of the protein by adjusting the conditions of the reaction (time, protein and iodide concentrations). 125-I, 131-I, and 127-I were used. Iodination increased the anodal mobility of TBG but did not affect the reversible T4-binding, precipitation by antiserum, or the heat-inactivation properties. "Heavily" and "lightly" iodinated TBG had identical disappearance half-times from serum in the rabbit. 15 min after the intravenous administration of [131-I]-STBG and [125-I]TBG mixture to rats, more than 90% of the injected 131-I dose was in the liver, and the liver 131-I/125-I ratio was 32-fold that of serum. Selective uptake of STBG by the liver was also observed in the rabbit and in man. The serum [125-I]STBG/[131-I]TBG ratio declined from 1 to 0.2 in 10 min in the intact rabbit but remained unchanged for 1 h in the acutely hepatectomized animal. In the rabbit, t 1/2 was approximately 3 min for STBG and 0.8-3.4 days for TBG. The radioiodine derived from the iodinated proteins is partly excreted in bile but the bulk was precipitable with specific antibodies. Some isotope in the form of iodide appeared in blood and was excreted in the urine. Since radioiodinated TBG and STBG preserve their biologic and immunologic properties they are useful as tracer materials for metabolic studies. In rat, rabbit, and man STBG is rapidly cleared from serum by the liver. Conversion of TBG to STBG may be the limiting step in the regulation of TBG metabolism.

Animals↗
PubMed1975

Study on maternal, fetal, and amniotic human prolactin at term.

Prolactin present in maternal blood, fetal blood, and amniotic fluid samples obtained simultaneously at term was examined. The relative concentrations of prolactin in maternal and fetal serum samples were found to vary with each individual case. However, amniotic fluid samples contained a much higher level of prolactin than did both maternal and fetal serum samples in every case. After gel filtration, three separate peaks of immunoreactive prolactin were observed, probably representing three different sizes of the hormone molecule. The main component was small prolactin, constituting at least 69% of the total prolactin immunoreactivity in blood samples and 90% in amniotic fluids. Prolactin was found to be very similar in cord venous and arterial sera, both quantitatively and in terms of heterogeneity. There were more noticeable differences in the percentages of medium and small prolactin present in serum samples than in amniotic fluid samples. Big prolactin was present in all samples; its percentage in maternal serum was slightly higher than its percentages in the other samples. These results suggest that: 1) The mother and fetus carry on independent secretion of prolactin during gestation. 2) The size heterogeneity of prolactin in amniotic fluid differs from maternal hPRL to a greater degree than it does from fetal hPRL. 3) The prolactin in amniotic fluid appears to be of fetal origin.

Amniotic Fluid↗