Browsing by Autor "Walter Bishop"

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    LEPTINA Y HORMONAS TIROIDEAS EN NIÑAS CON DIFERENTES DIAGNÓSTICOS NUTRICIONALES Y SU RELACIÓN CON LA MENÁRQUIA
    (2002) Gladys Marín de López; Ziomar López; Walter Bishop; Molina Viana; Leonor Hernández Yáñez
    Leptin and thyroid hormones in girls with different nutritional diagnosis and their relationship with menarche. An increment in the secretion of the Hipothalamic Gonadotropin Releasing Hormone (GnRH) is necessary for the beginning of puberty. Different factors have been related with this event, among these, the nutritional ones. The Leptin and the thyroid hormones regulate metabolism and corporal weight. The objective of this investigation was to study the secretion of Leptin and the thyroid function in pre and postmenarcheal girls with different nutritional diagnosis. Nutritional and anthropometric evaluation of 261 (6 – 14 years old) girls as well as quantification of fatty area, serum levels of Leptin, Thyroid Stimulating Hormone (TSH), Free Triyodotironine (FT3) and Free Tiroxine (FT4) was done. They were distributed according to the appearance of the menarche and nutritional diagnosis (NDX). The highest percentage of girls with menarche was observed in overweight girls. Also the highest serum Leptin levels and Fatty Area were detected in overweight girls. The production of Leptin in relation to Fatty Area was higher in the postmenarcheal overweight girls. The changes observed in the serum Leptin, TSH and FT3, in overweight pre and postmenarcheal girls and it possible relation with sexual maturation and menarche are discussed.
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    [Leydig cell function in experimental cryptorchism and varicocele in rats].
    (National Institutes of Health, 1999) Leonor Hernández-Yánez; Gladys Marín-López; Jesus A. Vilchez‐Martinez; Walter Bishop
    Leydig cells were isolated from testes of normal, cryptorchid and induced- varicocele rats. These cells were counted and coincubated with and without human Chorionic Gonadotropin (hCG) during 3 hours; thereafter, steroids were measured in the incubation media. Cryptorchid animals showed the lowest number of Leydig cells, the highest Progesterone response to hCG, a slight increment of testosterone and a decrease of estradiol. On the contrary, both left and right testes from varicocele induced rats showed a higher cell number (per g of tissue), lower progesterone response, slightly higher response testosterone and lower testosterone response. These results demonstrate that these conditions of testicular hyperthermia do not affect the number and function of Leydig cells to the same degree. This may be due to differences in the testicular temperature reached with each procedure.