Search results for "Gonad"
showing 10 items of 240 documents
Spermiogenesis in the vermetid gastropod Dendropoma petraeum (Gastropoda, Prosobranchia)
2002
The structure and maturation of the male gonad of the Mediterranean vermetid gastropod Dendropoma petraeum are described. Histological sections of the gonads were made throughout development and gonad activity was monitored at regular monthly intervals. During the autumn months the gonad is very small and is surrounded by a large quantity of connective tissue; it becomes more voluminous from December to August, with the highest growth peak in springtime. The stages of spermatogenesis were also observed and described.
Biochemical selection of prepubertal patients with androgen insensitivity syndrome by sex hormone-binding globulin response to the human chorionic go…
1997
Before puberty, the diagnosis of androgen insensitivity syndrome (AIS) can be difficult. We studied whether the decrease of sex hormone-binding globulin (SHBG) during the human chorionic gonadotropin (hCG) test may represent a biochemical test to select prepubertal patients with AIS. We examined prepubertal patients with AIS (n = 9, age 0.9-8.2 y), male pseudohermaphroditism not due to AIS (other-MPH) (n = 8, age 0.6-10.7 y), and control boys (n = 12, age 0.8-12.5 y). Testosterone and SHBG levels (mean +/- SD) were measured before (d 0) and after (d 5) a hCG test (1500 IU X 3 d). Testosterone levels (nmol/L) increased in all groups [AIS: from 1.5 +/- 1.2 to 22.1 +/- 11.8 (p0.001); other-MPH…
Treatment of cryptorchidism with a potent analog of gonadotropin-releasing hormone.
1978
Pernasal therapy of cryptorchidism with D-Leu6-des-Gly10-gonadotropin-releasing hormone ethylamide (D-Leu6-des-Gly10-GnRH-EA), a potent, long-acting GnRH analog, was attempted. Eleven prepubertal cryptorchid boys received between 25 microgram once daily and 25 to 50 microgram twice daily for 5 to 12 weeks. Complete testicular descent was achieved in 4 of the 11 boys. GnRH tests (1.5 microgram/kg intravenously), conducted in six boys before treatment, after 4 weeks of treatment, and in 2 boys 3 months after treatment, did not reveal changes in gonadotropin secretion indicative of precocious puberty or of decreased hypophyseal sensitivity to GnRH. Antibodies to the GnRH analog or to GnRH coul…
Sex differences in GABAA receptor binding in rat brain measured by an improved in vitro binding assay.
1990
The distribution of GABAA receptor sites was studied in female and male rat brain by an improved in vitro binding assay using 3H-muscimol and carefully washed membrane fractions. The binding studies revealed a single class of binding sites exhibiting the properties of GABAA receptors. The specific binding of 3H-muscimol was measured in four brain areas: the preoptic brain area, mediobasal hypothalamus, corticomedial amygdala and cerebral cortex. The equilibrium dissociation constants (KD) ranged from 11.2 to 23.3 nM in diestrous females and from 13.1 to 50.4 nM in males, the maximal number of binding sites (Bmax) from 3290 to 10240 fmol/mg protein in females and from 5495 to 17449 fmol/mg p…
The effects of sex hormones, prolactin, and chorionic gonadotropin on pineal electrical activity in guinea pigs.
1981
Microelectrophoretic application of sex hormones onto pineal cells in guinea pigs has shown different responses in pregnant females as compared to males. In pregnant females estrone caused excitation in 74% of the cells tested, while progesterone and testosterone, prolactin, and HCG were inhibitory in a majority of the cells tested, while progesterone and testosterone, prolactin, and HCG were inhibitory in a majority of the cells. In contrast, in males estrone caused excitation of only 19% but inhibition of 37%. A smaller percentage of cells was inhibited by progesterone, while the predominant response to testosterone was excitation. These results suggest that the pineal gland may be under …
Familial insulin resistant diabetes associated with acanthosis nigricans, polycystic ovaries, hypogonadism, pigmentary retinopathy, labyrinthine deaf…
1993
Two sibs, whose parents are first cousins, had diabetes mellitus with hyperinsulinism, insensitive insulin receptors, and acanthosis nigricans. Both patients had pigmentary retinopathy, secondary cataracts, labyrinthine deafness, mental retardation, and cerebral atrophy. They were disproportionately short with relatively broad hands and feet and slightly coarse face. The young woman had secondary amenorrhea and polycystic ovaries and the boy gynecomastia and hypergonadotrophic hypogonadism. This appears to be the second family with a new autosomal recessive disorder differing from Alstrom syndrome by the presence of mental retardation and absence of renal insufficiency. Impaired insulin rec…
Management of undescended testes: European Association of Urology/European Society for Paediatric Urology Guidelines.
2016
Summary Context Undescended testis is the most common endocrinological disease in the male newborn period. Incidence varies between 1.0% and 4.6% in full-term neonates, with rates as high as 45% in preterm neonates. Failure or delay of treatment can result in reduced fertility and/or increased testicular cancer risk in adulthood. Objective To provide recommendations for the diagnosis and treatment of boys with undescended testes which reduce the risk of impaired fertility and testicular cancer in adulthood. Evidence acquisition Embase and Pubmed were searched for all relevant publications, from 1990 to 2015 limited to English language. Data were narratively synthesized in light of methodolo…
Actions of sex hormones on the brain
1992
1. The brain is a target for sex steroid hormones. As a result of sex hormone actions on the brain various behavioral changes are observed in animal and man. This paper gives a brief overview over the multiple central nervous functions that are under modulatory control of sexual hormones and describes the complex sex steroid actions on the brain by giving an example for "activating" and "organizing" effects of estrogens on noradrenergic neurons in the brain of rats. 2. Estradiol-17 beta induced sex specific alterations in the turnover of noradrenaline in the preoptic area and mediobasal hypothalamus showing "female" or "male" responses. 3. Neonatal manipulations of female rat pups by testos…
Effects of heavy resistance/power training on maximal strength, muscle morphology, and hormonal response patterns in 60-75-year-old men and women.
2002
Eleven women (TRW; 64 ± 4 yrs) and ten men (TRM; 65 ± 5 yrs) participated in the strength/power training twice a week for 24 weeks. Basal concentrations of serum total and free testosterone, growth hormone (GH), dehydroepiandrosterone sulfate (DHEAS), cortisol and sex hormone binding globulin (SHBG) as well as acute responses of serum total and free testosterone, growth hormone (GH) were measured. Maximal 1RM strength in the squat, chair rise time and muscle fibre distribution and areas of type I and IIa and IIb of the vastus lateralis were also examined. 1RM squat increased in TRW by 26 (SDIO) % (p < .001), and in TRM by 35(7) % (p < .001) and chair rise time improved in both groups…
The impact of ovarian stimulation on the expression of candidate reprogramming genes in mouse preimplantation embryos.
2012
Ovarian stimulation with gonadotrophins is an integral part of assisted reproductive technologies in human subfertility/infertility treatment. Recent findings have associated ovarian stimulation with the increased incidence of imprinting disorders in humans as well as defects in genome-wide methylation reprogramming and, in particular, imprinting in mice. Here, we present the first study that determined the impact of ovarian stimulation on the expression of developmentally important reprogramming genes <i>(Apex1, Lig1, Lig3, Mbd2, Mbd3, Mbd4, </i>and<i> Polb)</i> in single early mouse morula embryos (16-cell stage). Using absolute quantification of mRNA by quantitati…