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PubMed1992

Sexual development and free-running period in quail kept in constant darkness.

In Japanese quail (Coturnix coturnix japonica) sexual development may occur in total darkness (DD). Linked to sexual maturation, variations of the rhythm of feeding activity were observed: in DD, the amount of activity increased and the period of the free-running rhythm lengthened. During the first weeks in DD all the quails presented a free-running period less than 24 hr (22.3 +/- 0.5 hr; N = 50). At the end of the experiment, the more a bird was mature, the greater the lengthening of its period. In DD, testosterone implants in castrated male quails can mimic these modifications but we failed to find any correlation between the number of implants (i.e., the level of testosterone) and the extent of the lengthening.

Activity Cycles↗
PubMed1990

[Sexual development in obese women].

By means of an interview and the questionnaire "Heterosexual Development of Women" [HDW] the authors subjected to sexuological examination 129 obese women aged 20-50 years with a body mass index above 25. As regards the time when overweight developed 29 women developed obesity during the prepubertal period and in 100 of the women obesity developed during adolescence and later. It was revealed that the sexual development of obese women was normal. The mean values in the HDW questionnaire in both subgroups with a different period of development of overweight were all within the normal range.

Adult↗
PubMed1986

[Sexual development and levels of plasma testosterone in the light type of cockerel].

The concentration of testosterone in blood plasma during the ontogenetic development of cockerels was studied in relation to the development of spermatogenic part of gonads. On the basis of the results, sexual development of cockerels can be divided into three stages. The first stage (from hatching to the age of eight to nine weeks) was characterized by a slow increase in gonad weight, by low concentration of plasma testosterone (0.4-2.0 nmol/l) and by the occurrence of spermatogonia in testes. In the course of the second stage (from the age of nine to 16 weeks) a rapid increase in the weight of testes and testosterone concentration was observed. At the end of this stage all phases of spermatogenic cycle were observed in gonads; the testosterone levels averaged to 10 nmol/l. In the course of this stage all cockerels reached sexual maturity; large individual differences in spermatogenesis development were observed. The third stage (16 weeks of age and more) was characterized by an intensive spermatogenesis, further increase in gonad weight and by typical variations of the plasma testosterone levels. The concentration of the circulating testosterone increased before the onset of the final stages of the spermatogenic cycle.

Animals↗
PubMed1984

A novel cyclic AMP metabolism exhibited by giant cells and its possible role in the sexual development of Dictyostelium discoideum.

In Dictyostelium discoideum cyclic AMP (cAMP) metabolism during macrocyst development, i.e., the sexual cycle of this organism, and in giant cells, i.e., fusion products from opposite mating-type cells, was investigated. The pattern of change in cAMP levels during macrocyst development differed considerably from that observed during fruiting-body formation, i.e., the asexual cycle. Giant cells produced and excreted considerable amounts of cAMP. Adenylate cyclase activity catalyzing cAMP production in giant cells was comparable to that of unfused cells. However, the activity of membrane-bound phosphodiesterase in giant cells was extremely low, and no extracellular phosphodiesterase was excreted. A phosphodiesterase inhibitory protein was secreted in excess by giant cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1982

Adrenocortical function in children with precocious sexual development during treatment with cyproterone acetate.

Adrenal function was studied in thirty-two children with precocious sexual development who were being treated with cyproterone acetate (CPA) at doses ranging from 68 to 175 mg. m2. day for periods lasting from 2 to 79 months. In eighteen children the adrenocortical function evaluation was made before and during CPA treatment. In these eighteen patients, the mean basal plasma cortisol level during the morning hours was 11.2 +/- 4.6 micrograms/dl (m +/- SD) before treatment and fell significantly to 7.2 +/- 4.1 micrograms/dl (P less than 0.02) during therapy. In fifteen patients tested during insulin hypoglycaemia the cortisol peak fell from 21.6 +/- 5.5 micrograms/dl before treatment to 16.7 +/- 6.8 micrograms/dl (P less than 0.05) during CPA therapy. There was a significant inverse correlation between this peak and the dose of CPA but no correlation was found between the cortisol response and duration of treatment. In eight of twenty patients tested, urinary free cortisol levels were undetectable during treatment. No change in basal plasma ACTH levels were demonstrated using standard radioimmunoassay techniques. In the patient receiving the highest dose of CPA and showing complete suppression of the adrenal axis, prolonged stimulation with ACTH-Depot demonstrated a responsive adrenal gland. Addition of a replacement dose of cortisol to the CPA treatment led to the rapid development of the typical signs of Cushing's syndrome. It was concluded that despite the evidence of adrenal suppression by CPA, cortisol supplementation is not necessary and may not even be contraindicated.

Adrenal Cortex↗
PubMed1991

[Abnormalities of sexual development in Puerto Rico: status report].

Puerto Rico presents the highest incidence in the world of anomalous sexual development. The authors have collected over 3100 cases in the past 19 years. Clinical and laboratory studies suggest possible estrogenic contamination of meats and poultry products. Variation in diet provides protection to a significant number of patients. The possibility of mycotic contamination of food employed in animal husbandry by Fusarium sp., and mycotoxins capable of estrogenic effects have been suggested in a preliminary study. Private and government investigators are active in the study of the condition, but more fiscalizing action is needed. A detailed study of food components for possible contaminants determination is considered mandatory.

Adolescent↗
PubMedDate not supplied

[Androgenic function of the adrenal cortex in girl athletes with retarded sexual development].

Diurnal excretion of 17-ketosteroids and their fractions was studied in 43 girl athletes with retarded sexual development (RSD) and 22 patients who did not go in for sports. Twenty-five healthy girls with a normal menstrual cycle constituted the control group. Athletes with RSD showed relative hyperandrogeny marked by a higher proportion of more active androgenic fractions (dehydroepiandrosterone and androsterone) in total 17-ketosteroids. Excretion of neutral 17-ketosteroids in athletes examined, as compared with non-athletes with RSD, was within age-associated norms or surpassed them. It is suggested that androgens of the adrenal cortex are involved into the pathogenesis of RSD in female athletes.

Adolescent↗
PubMed1979

Cytogenetic and endocrine studies in a 45,X female subject with spontaneous sexual development.

Cytogenetic and endocrine evaluation of a postpubertal 45,X female subject with Turner's stigmas and spontaneous sexual development was performed. A 45,X chromosomal complement was found in the peripheral blood lymphocytes, bone marrow, and fibroblasts derived from skin and ovaries. Menarche, pubarche, and thelarche occurred at age 12; at age 16 she developed menstrual irregularities, with endometrial bleeding occurring every 60 to 90 days. The ovaries were normal in size, and histologic examination revealed a marked paucity of primordial follicles, increased collagenization, and absence of corpora albicans. Anovulatory cycles with moderately elevated levels of luteinizing hormone (LH) and low follicle-stimulating hormone (FSH) levels were observed. LH-releasing hormone pituitary stimulation induced a normal LH release with a very slight FSH increase. Administration of clomiphene citrate successfully induced a normal-length ovulatory cycle. Similarities in the hormonal situation of this patient and that seen in the Stein-Leventhal syndrome are pointed out.

Adolescent↗
PubMed1979

Aggregation during sexual development in Dictyostelium discoideum.

A microcinematographic analysis of the behaviour and movements of cells and cell masses in mated cultures (NC4 X VI2) of Dictyostelium discoideum indicates that a chemotactic process directs cell aggregation during macrocyst development. Zygote giant cells form before aggregation begins and act as the aggregation centres. Young multicellular macrocyst stages are sources of cyclic AMP, and amoebae from macrocyst cultures orient chemotactically to cyclic AMP. The data, coupled with other characteristics such as pulsatile streaming, suggest that the aggregation process leading to macrycyst development is the same as that occurring during fruit construction. Other aspects of sexual development are also discussed. Based upon these data, we propose a model for the sequence of events leading to macrocyst development in D. discoideum.

Chemotaxis↗
PubMed1989

The control of sexual development in Drosophila melanogaster: genetic and molecular analysis of a genetic regulatory hierarchy--a minireview.

Genetic analyses of mutants affecting the sexual development of the fruitfly, Drosophila melanogaster, have led to a genetic model that describes how the wild-type genes interact with one another as parts of a single regulatory pathway. More recent molecular studies on some of these sex differentiation regulatory genes have lent support to this genetic model, and have defined the molecular nature of some of these genetic interactions. One surprising feature of the regulatory hierarchy to emerge from these molecular studies is that many of the sex-specific genetic switches in this pathway are not transcriptional regulation events but, rather, are based on sex-specific alternative RNA processing events (pre-mRNA splicing and/or polyadenylation site selection).

Animals↗
PubMed1987

A survey on growth and sexual development of adolescent students in Changhua City: growth of body height and weight.

In order to understand the physical growth and sexual development of contemporary adolescents, a cross-sectional survey was conducted during the period September 1983 to May 1984. The population came from all the pupils from 4th grade up, and all the junior and senior high students of Changhua City. By using stratified cluster sampling, 1419 boys and 1599 girls participated, ranging in age from 8 to 19 years. Body weight and height were measured. Growth spurt is a unique event during adolescence. It is well shown in the distance curves and pseudo-velocity curves of body height and weight. In boys, the growth spurt of height spanned from 12.0 to 14.8 years, with peak height velocity (PHV) at 13.5 years. In girls it was from 10.0 to 12.6 years and peaked at 11.5 years. The growth spurt of weight occurred from 12.0 to 15.9 years in boys with peak weight velocity (PWV) at 14.5 years, while girls had a growth spurt at 10.0-12.7 years with PWV at 11.5 years. Girls entered into the growth spurt about 2 years earlier, and also entered into PHV, PWV, two and three years earlier respectively than boys, while boys had a more intense and longer growth during the growth spurt than girls. Between 10.0-13.0 years girls were taller than boys, and between 12.0-13.0 years they were heavier than boys. However, from 13.5 years onward girls were soon surpassed by boys both in height and weight. Growth in height after 16.5 years in boys and after 15.5 in girls was minimal. Growth in weight in boys also became minimal after 16.5 years while girls weight even dropped a little bit after 16.5 years. At the mean age of 17.5 years, boys were 168.1 cm, girls were 156.2 cm in average, boys being 12 cm taller than girls after reaching their final height.

Adolescent↗
PubMedDate not supplied

Virilizing hepatoblastoma: precocious sexual development and partial response of pulmonary metastases to cis-platinum.

A 42/3 year old boy with hepatoblastoma presented with precocious sexual development and an abdominal mass. During the course of disease, serial endocrinologic laboratory investigations were done, along with alpha-fetoprotein levels. A significant correlation is noted in these values at diagnosis, postsurgery, and later during a relapse. Ectopic production of chorionic gonadotropins by the tumor is evident. After extensive surgical resection, chemotherapy was started because of metastases. Although the primary tumor failed to respond, the pulmonary metastatic disease showed a greater than 50 percent response rate with cis-platinum.

Carcinoma, Hepatocellular↗
PubMed1983

Male sexual development in the monkey. I. Cross-sectional analysis of pulsatile hypothalamic-pituitary-testicular function.

Pulsatile secretion of serum gonadotropins and testosterone was studied in 46 monkeys of varying ages from 9 days of age through adult life. Although some of the hormonal analysis was longitudinal in nature, most comparisons were cross-sectional. On the basis of pulsatile secretory patterns, hCG and GnRH stimulation, skeletal age, testicular volume, and histology, we have arbitrarily defined four developmental age groups: postnatal (less than 7 months), prepubertal or juvenile (7-27 months), pubertal (28-59 months), and adult (greater than or equal to 60 months). In accomplishing the pulsatile studies, blood was withdrawn at 15-min intervals over 24 h without anesthesia using a mobile vest and tether assembly to support an indwelling cannula. GnRH and hCG challenge tests were done on one or more occasions on all animals. Plasma samples were analyzed for concentrations of FSH, LH, testosterone, dihydrotestosterone and delta 4-androstenedione by established RIAs and an in vitro bioassay for LH. During the frequent sampling period of 24-h duration for all except postnatal animals, testosterone pulses of large amplitude (up to 8-fold) occurred in postnatal, pubertal, and adult animals. Pulsatile gonadotropin secretion was seen at all ages; however, the highest pulses (up to 15-fold) occurred in prepubertal animals even though this was an infrequent occurrence. Time series analysis techniques were applied for objective statistical characterization of cyclic patterns. Basic rhythms corresponding to 50- to 90-min frequency cycles in gonadotropin secretion were identified. Substantive differences between LH concentrations by bioassay and RIA were seen infrequently. Our findings illustrate that: 1) circulating gonadotropin and testosterone pulses change in amplitude but not necessarily frequency during pubertal development, and 2) primate models are a useful paradym for the longitudinal study of human male sexual development. We conclude that where direct human investigation may be limited, much can be learned by study of these primate surrogates.

Age Determination by Skeleton↗
PubMedDate not supplied

[Pathogenesis of functional retardation of physical and sexual development in adolescents. Status of somatotropic and gonadotropic function].

A study of somatotropic and gonadotropic functions in male adolescents with functional retardation of physical and sexual development has shown an important role of the deficiency of gonadotropins, especially FSH, in the pathogenesis of this condition. LH secretion in retarded physical development (RPD) is lowered to a lesser degree and positively correlates with testosterone deficiency. The feedback in the hypothalamohypophyseogonadal function in RPD is less frequently affected and to a lesser degree than gonadotropic functions. Of the tested methods (tests with TRH, L-DOPA and bromocriptine) STH reserves are better revealed with L-DOPA and TRH tests, gonadotropic reserves, especially LH,--with TRH and bromocriptine tests. The stimulating TRH effect on the growth hormone is indicative of the versatility and nonspecificity of its action on the pituitary gland in functional developmental disorders.

Adolescent↗
PubMed1983

Influence of testosterone and/or luteinizing hormone releasing hormone analogue on precocious sexual development in the juvenile rainbow trout.

The influence of testosterone, luteinizing hormone releasing hormone (LHRH) agonist and combinations of these hormones on gonadotropic hormone (GtH) levels in the sexually immature trout was investigated. Both the steroid and releasing hormone preparations, testosterone in Silastic capsules and cholesterol-pelleted LHRH-A, were formulated for sustained release and long-term biological action following a single hormone implantation. Marked increases in pituitary GtH followed testosterone and/or testosterone and LHRH analogue treatment combined, but the low pituitary GtH level in controls remained unchanged after LHRH analogue administration alone. Plasma GtH titers increased with time after testosterone treatment, indicating a positive steroid feedback effect by androgen on GtH in the juvenile rainbow trout. When combined with testosterone treatment, LHRH analogue augmented plasma GtH levels compared to fish receiving testosterone treatment alone. In males the elevated plasma GtH levels were associated with testes stimulation and onset of spermatogenesis; in females, however, no significant stimulation of the ovaries was observed. It can be concluded from these studies that the testosterone stimulus is sufficient to induce onset of sexual development in immature males but not females. Whereas LHRH analogue releases GtH from the testosterone-primed trout pituitary, LHRH treatment alone under these conditions fails to stimulate the juvenile trout reproductive system.

Animals↗
PubMed1983

Male sexual development in the monkey. II. Cross-sectional analysis of pulsatile hypothalamic-pituitary secretion in castrated males.

Pulsatile secretion of serum gonadotropins was studied in 16 castrated monkeys from 4 weeks of age through adult life. Animals were castrated at various ages from birth through adult life. Although some studies of the gonadotropin-secretory patterns were longitudinal in nature, most comparisons were cross-sectional. On the basis of our observations, we have arbitrarily grouped the animals into 4 developmental ages: postnatal (less than 7 months), prepubertal or juvenile (7-27 months), pubertal (28-59 months), and adult (greater than or equal to 60 months). In carrying out these studies, blood was withdrawn at 15-min intervals over 24 h without anesthesia using a mobile vest and tether assembly to support an indwelling catheter. GnRH challenge tests were done on 1 or more occasions on all animals. Plasma samples were analyzed for concentrations of FSH and LH by established RIAs and an in vitro bioassay for LH. During the frequent sampling period (24 h for all except postnatal animals), the amplitude of gonadotropin pulses was greatest in adult animals followed by postnatal and pubertal monkeys. During pubertal development, there was a marked increase in the magnitude of gonadotropin pulses, and remarkedly, there was a substantial increase in the LH bioassay: RIA (greater than 5:1) by adult life. GnRH challenge tests of gonadotropins correlated with these observations. Time series analysis was applied to the data for objective statistical characterization of cyclic patterns. Our findings can be summarized: 1) during pubertal maturation there is a change in amplitude but not frequency of gonadotropin pulses, 2) pubertal development of the hypothalamic-pituitary axis advances in the absence of gonadal feedback, and 3) there is a significant increase in the LH bioassay: RIA during pubertal development. We conclude that the castrate monkey is a valuable adjunct to direct clinical investigations of the mechanisms controlling human sexual development.

Age Factors↗
PubMed1989

Effect of zeranol on sexual development of crossbred bulls.

Three groups of 1/2 Simmental X 1/4 Brahman X 1/4 Hereford bull calves were used during two different years to study effects of zeranol on sexual development. At 154 d of age, half the calves were implanted with 36 mg zeranol and half, not implanted, served as controls. Implanted calves were reimplanted at 90-d intervals throughout the trial (9 mo) each year. Trial 1 was conducted with 24 calves and Trial 2 was conducted the following year with 10 bulls. Twenty-four days after weaning (200 d of age) and at 28-d intervals thereafter, bulls in drylot in Trial 1 were weighted, scrotal circumference (SC) was measured and an ejaculate of semen was collected by electroejaculation to determine puberty. At these times, bulls were given 200 micrograms of GnRH i.m. and blood was collected at 0, 1, 2, 3, 4 and 5 h after GnRH. Serum concentrations of LH and testosterone (TEST) were determined. At slaughter, testis weight, length and circumference and pubertal status were recorded. Bulls implanted with zeranol had smaller SC than control bulls during the entire 9-mo period (P less than .0001). More control bulls reached puberty than did implanted bulls (82.4 vs 23.5%, respectively; P less than .001). Control bulls had larger testis measurements at slaughter (P less than .0001). Implants did not alter total weight gain or ADG (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗