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PubMedDate not supplied

[Epidemiologic characteristics of nutrition of school children at high risk for developing ischemic heart disease and atherosclerosis].

The results of the investigation of a representative sample of Moscow schoolchildren, aged 11-14 years, are described. The investigation included a triple arterial pressure measuring, anthropometry, numerical score of sexual development, assay of cholesterol, triglycerides and high-density lipoprotein cholesterol levels in the blood serum. The character of nutrition of 250 (20% of the sample) schoolchildren was studied by the method of dietary inquiry (daily ration) with the use of food patterns. The data of the multivariative analysis have shown that sexual development, a low educational level of the parents (among them subjects engaged in the manual labor being predominant) influence the development of the risk factors of ischemic heart disease and atherosclerosis. Composition of food is of great importance, especially for boys with dislipoproteinemias (low consumption of starch per 1 kg bw, high consumption of total protein, low consumption of fat in cal %), and for those with excessive body mass and low physical activity (low consumption of total fat, polyunsaturated fat per 1 kg bw, as well as high consumption of total protein in cal %).

Adolescent↗
PubMedDate not supplied

[Clinico-electroencephalographic study of familial (genetic) forms of nanism].

Genetic nanism is a widespread phenomenon. Only familial forms constituted 22.8% of the cases of hypophysial and cerebral nanism. A total of 32 patients belonging to 15 families with repeated cases of the disease were examined clinically and electroencephalographically. In genetic hypophysial nanism clinical peculiarities of the disease and the EEG indices were similar within the limits of the same family and showed distinct differences in the patients belonging to different families. The differences are determined chiefly by the level of sex maturation. The EEG in genetic hypophysial nanism was identical to that in the total group of patients with the hypophysial nanism without any organic cerebral pathology. The EEG of the sexually immature patients suffering from nanism was characterized by the immaturity features both in the prepubertal period and in the course of the whole following life, whereas in the patients with a spontaneous sexual development the EEG corresponded to the age criteria at any age. The EEG examination of the patients with hypophysial nanism at the prepubertal period permits to prognosticate their subsequent sexual development.

Adolescent↗
PubMed1984

Daily afternoon administration of melatonin does not irreversibly inhibit sexual maturation in the male rat.

Previous studies from our laboratory demonstrated that daily afternoon melatonin injections from 20-40 days of age inhibited sexual development of young male rats, whereas in adult animals, similar injections had no effect. The present study was designed to determine more precisely the critical age period during which melatonin exerts its inhibiting effect and to see whether spontaneous sexual maturation resumes after discontinuation of melatonin administration at 45 days of age or even during continuous administration of melatonin until 115 days of age. Sexual maturation was evaluated using weights of seminal vesicles and testes; plasma levels of testosterone, FSH, and LH; pituitary contents and concentrations of FSH and LH; and, finally, pituitary content of GnRH receptors. Administration of melatonin to young male rats from 20-30 days of life had the same inhibitory effect on sexual maturation at 40 days as melatonin injections from 20-40 days. In contrast, administration of melatonin from 30-40 days only slightly decreased plasma testosterone concentration, weight of seminal vesicles, and pituitary GnRH receptor content. Melatonin administration from 38-40 days had no effect. Daily melatonin administration from 20-45 days of age was followed by resumption of sexual maturation, as observed at 70 days. The recovery was complete by 80 days of age when all of the parameters studied reflected complete sexual maturation. Finally, in rats treated continuously with melatonin from days 20 until 115, sexual maturation occurred but was delayed by about 20-30 days. Beginning of sexual development was observed at 60 days of life, and full development was attained only at 100 days. These data confirm that melatonin delays sexual maturation in the young male rat when administered daily in the afternoon. They demonstrate that this inhibitory action of melatonin is most critical between 20 and 30 days of life and is reversible regardless of whether melatonin administration is discontinued after 45 days of life. The suppression of the pubertal peaks of pituitary GnRH receptor number and pituitary and plasma FSH concentrations in treated rats suggests that melatonin interferes with the pubertal increase in GnRH secretion. In conclusion, these reversible effects of melatonin suggest that this pineal indolamine represents an important factor for the timing of sexual maturation.

Aging↗
PubMed1995

Genital bleeding in premenarcheal children.

OBJECTIVE: The earlier occurrence of secondary sexual development and the advance in diagnostic techniques prompted us to review our recent experience with genital bleeding in childhood. METHOD: We analyzed data for all patients aged less than 10 years who were referred to Gifu University School of Medicine-affiliated hospitals from 1984 through 1993. RESULTS: From a total of 330 girls, 62 (approximately 20%) complained of genital bleeding. The patients were distributed equally between 0 and 10 years of age. In 46 of 62 patients (74%), bleeding resulted from a local lesion of the vagina: 28 due to vulvovaginitis, six to urethral prolapse, six to trauma, three to foreign bodies and three to vaginal tumors. Malignant vaginal tumors were seen in two patients: sarcoma botryoides and endodermal sinus tumor. Both were diagnosed by histopathological examination of an exophytic vaginal tumor, with several weeks' interval from the initial episode of bleeding to diagnosis. The remaining 16 patients (26%), with no demonstrable local lesions, bled as a result of some form of precocious puberty. In six patients, precocious puberty was secondary to a hormonally active ovarian tumor, five of these patients also experiencing advanced breast development. Routine ultrasound and hormonal evaluations promptly detected the presence of tumor. None of three patients with idiopathic precocious puberty presented with secondary sexual development. No specific etiology was established in seven patients. CONCLUSION: Genital bleeding alerts us to the possibility, though rare, of a genital tract tumor. Prompt and precise detection may lead to cure and preservation of future fertility.

Age Distribution↗
PubMed2003

Thyroid function and puberty.

Thyroid hormones are essential for normal growth, sexual development and reproductive function. During puberty, changes in thyroid functions and an increase in thyroid volume occur as an adaptation to body and sexual development. Hypothyroidism diagnosed late in prepubertal years, usually due to Hashimoto's thyroiditis, can cause a delay of puberty or incomplete isosexual precocity (development of breast and internal genitalia in girls and increased testis volume in boys without adrenarche). In contrast, normal pubertal development and adequate menarche have been documented in congenital hypothyroidism detected by neonatal screening and treated early. The effect of hyperthyroidism on pubertal development is not well known, but a short period of hyperthyroidism seems not to have major negative effects. In adolescence or young adulthood, menstrual dysfunction, infertility, and stillbirth or premature birth are associated with thyroid dysfunction.

Female↗
PubMed1984

The role of androgen in the development of sexual differences in pituitary responsiveness to gonadotropin releasing hormone (GnRH) agonist in the bullfrog, Rana catesbeiana.

Sexual differences in pituitary responsiveness to acute injection of gonadotropin-releasing hormone (GnRH) agonist, as measured by increments in plasma FSH and LH, were examined throughout development in the bullfrog, Rana catesbeiana. Untreated tadpoles, in various stages of metamorphosis, were unresponsive to GnRH agonist. Postmetamorphic males showed a progressive increase in the magnitude of pituitary response with age, whereas females remained relatively insensitive until after sexual maturation; males were always more responsive than females. Chronic (1-2.5 week) Silastic implants containing 5 alpha-dihydrotestosterone (DHT) significantly augmented the pituitary response (for both gonadotropins) in intact postmetamorphic females at all ages; a similar, though less pronounced, action of testosterone in subadult females may have been due to its conversion to DHT. (Silastic implants of comparable size always produced higher circulating levels of DHT in females than in males as was observed in previous studies with gonadectomized frogs.) DHT enhanced the responsiveness of intact tadpoles (sexes undetermined); only the treated tadpoles responded to the GnRH agonist. Supplemental DHT did not enhance pituitary response in intact males; in fact, it attenuated the response in FSH. GnRH responsiveness paralleled changes in pituitary gonadotropin content; pituitary content of FSH and LH was higher in males than females; it showed a marked increase with age from tadpole to adult; and it was increased by DHT treatment. The potentiating effect of DHT on GnRH responsiveness and the significantly higher levels of DHT observed in males of all ages suggest that the nonaromatizable androgen DHT may be responsible for the early establishment and maintenance of sexual dimorphism in pituitary GnRH responsiveness in the bullfrog.

Animals↗
PubMed2004

Expression of axon guidance molecules and their related genes during development and sexual differentiation of the olfactory bulb in rats.

Axon guidance molecules and related proteins such as semaphorin 3A, neuropilin-1, plexin-1, netrin-1, growth-associated protein, olfactory marker protein, cypin and collapsin response mediator proteins guide the development of neural circuits in the olfactory bulb. In this study, transcriptions of these genes were examined in the olfactory bulb of female, male and neonatal testosterone propionate-treated female rats at the ages of 2, 5, 10, 15, 20, 25, 30 and 45 days. The semaphorin 3A, neuropilin-1, growth-associated protein and collapsin response mediator protein 1-5 genes were expressed significantly higher during the early development stages than in adulthood while the opposite is true for the olfactory marker protein. The expression profile of cypin and netrin-1 was relatively constant through development. A late effect of the neonatal testosterone propionate treatment on netrin-1, growth-associated protein, olfactory marker protein, collapsin response mediator proteins 1, 3, 4 and cypin gene expression was observed. The expression profiles of collapsin response mediator proteins and their related genes in the developing olfactory bulb confirmed most studies on the relationship between collapsin response mediator proteins and development in the brain. Sex differences of semaphorin 3A, neuropilin-1 as well as collapsin response mediator protein 3 at the early development stage and the late effect of neonatal testosterone propionate treatment on the expressions of netrin-1, growth-associated marker protein, cypin and collapsin response mediator proteins 1, 3 and 5 genes may indicate a possible role of these molecules on sexual differentiation of the olfactory bulb.

Adaptor Proteins, Signal Transducing↗
PubMed1980

Impaired sexual maturation associated with sleep apnea syndrome during puberty: a case study.

A 20-year-old hypogonadal man was discovered to have had obstructive sleep apnea syndrome--secondary to hypertrophied tonsils, adenoids, and uvula--spanning the years of puberty. All-night polysomnographic recordings and 24 hr measurements of plasma luteinizing hormone (LH) concentrations (sampling at 20 min intervals) were performed before and after combined tonsillectomy, adenoidectomy, and uvulectomy. Two weeks preoperatively, nocturnal sleep was markedly disturbed by 407 apneic episodes, and the patient was found to be hypogonadotropic. Daytime LH concentrations were in the low-normal range for an adult male, and concentrations fell dramatically during nocturnal sleep. This contrasts with both the sleep-related elevation of LH normally seen in puberty and the adult pattern, where no difference is observed in mean concentrations during waking and sleep. Two week and 6 month postoperative evaluations revealed complete alleviation of the sleep apnea syndrome and normalization of the 24 hr pattern of plasma LH, although LH values remained in the low-normal range. Plasma testosterone concentrations were in the low to low-normal range both pre- and postoperatively. No evidence of continued sexual development, beyond that achieved preoperatively, was observed 20 months after surgery, despite continued relief from apnea. These data suggest that sleep apnea during puberty may impair sexual development by preventing the sleep-related elevation in LH secretion normally observed during a critical period spanning puberty.

Adenoidectomy↗
PubMed1985

The role of postnatal testosterone in the development of sexually dimorphic behaviors in DBA/1Bg mice.

The DBA/1 Y chromosome causes an increment in aggression and pubertal testosterone levels. The purpose of the following experiments was to determine whether pubertal testosterone is necessary for the normal development of both aggression and copulation in males. If it is, then the effect of the DBA/1 Y chromosome may be mediated by its influence on pubertal testosterone. Individuals were either castrated at 30 days of age (CAS30) or sham operated (Sham or CAS50). At 50 days of age, the CAS30 individuals were sham operated and replaced with testosterone, while the CAS50 group was castrated and replaced with the same quantity of testosterone. The shams were sham operated at 50 days of age. CAS30 individuals were less aggressive than the CAS50 group, while they were no less aggressive than the sham operated group. Additionally, no groups differed in male copulatory behaviors. The results are discussed in relation to Y chromosomal and developmental mechanisms of sexually dimorphic behaviors.

Age Factors↗
PubMed1994

Two types of RAS mutants that dominantly interfere with activators of RAS.

In the fission yeast Schizosaccharomyces pombe, ras1 regulates both sexual development (conjugation and sporulation) and cellular morphology. Two types of dominant interfering mutants were isolated in a genetic screen for ras1 mutants that blocked sexual development. The first type of mutation, at Ser-22, analogous to the H-rasAsn-17 mutant (L. A. Feig and G. M. Cooper, Mol. Cell. Biol. 8:3235-3243, 1988), blocked only conjugation, whereas a second type of mutation, at Asp-62, interfered with conjugation, sporulation, and cellular morphology. Analogous mutations at position 64 of Saccharomyces cerevisiae RAS2 or position 57 of human H-ras also resulted in dominant interfering mutants that interfered specifically and more profoundly than mutants of the first type with RAS-associated pathways in both S. pombe or S. cerevisiae. Genetic evidence indicating that both types of interfering mutants function upstream of RAS is provided. Biochemical evidence showing that the mutants are altered in their interaction with the CDC25 class of exchange factors is presented. We show that both H-rasAsn-17 and H-rasTyr-57, compared with wild-type H-ras, are defective in their guanine nucleotide-dependent release from human cdc25 and that this defect is more severe for the H-rasTyr-57 mutant. Such a defect would allow the interfering mutants to remain bound to, thereby sequestering RAS exchange factors. The more severe interference phenotype of this novel interfering mutant suggests that it functions by titrating out other positive regulators of RAS besides those encoded by ste6 and CDC25.

Base Sequence↗
PubMedDate not supplied

Adolescent pregnancy. Teen perspectives on prevention.

PURPOSE: To elicit the views of teens concerning effective strategies to prevent pregnancy. DESIGN: Qualitative methods and a focus group approach were used. METHOD: The sample consisted of male and female adolescents, 14 to 19 years of age, in grades 9 to 12, who volunteered to participate in the study. Seven groups of teens met with the investigator twice over 2 consecutive weeks. Instruments included a Screening Questionnaire and Focus Group Discussion Guidelines. RESULTS: Teens were concerned about teen pregnancy, and supported a comprehensive approach to sex education beginning in the early elementary grades, with age and developmentally appropriate content and reinforcement from late grade school through high school. Generally, teens thought that teaching abstinence in grade school followed by contraception education in junior high and high school was a realistic strategy for pregnancy prevention. They wanted to discuss sexual feelings as well as the mechanical aspects of sex. Finally, they did not want to be told not to have sex, but rather wanted to be guided in their own decision making. Teens wanted parents and other adults to be involved in helping them understand sexuality and make decisions about sexual behavior. CLINICAL IMPLICATIONS: Nurses who work with families need to understand why teens are becoming pregnant, provide opportunities for teens to discuss sexual behavior, and educate parents on sexual development and parent-child communication. Nurses also need to let parents and teens know that they are a resource for information, guidance, and health services related to sexual development and behavior.

Adolescent↗
PubMed1998

An autosomal or X linked mutation results in true hermaphrodites and 46,XX males in the same family.

It is now well established that the differentiation of the primitive gonad into the testis during early human embryonic development depends on the presence of the SRY gene. However, the existence of total or partial sex reversal in 46,XX males with genetic mutations not linked to the Y chromosome suggests that several autosomal genes acting in association with SRY may contribute to normal development of the male phenotype. We report a family in which four related 46,XX subjects with no evidence of Y chromosome DNA sequences underwent variable degrees of male sexual differentiation. One 46,XX male had apparently normal male external genitalia whereas his brother and two cousins had various degrees of sexual ambiguity and were found to be 46,XX true hermaphrodites. The presence of male sexual development in genetic females with transmission through normal male and female parents indicates that the critical genetic defect is most likely to be an autosomal dominant mutation, the different phenotypic effects arising from variable penetrance. Other autosomal loci have been implicated in male sexual development but the genetic mechanisms involved are unknown. In this family there may be an "activating" mutation which mimics the initiating role of the SRY gene in 46,XX subjects.

Adult↗
PubMed1990

Effect of age at the start of iron chelation therapy on gonadal function in beta-thalassemia major.

BACKGROUND: Patients with transfusion-dependent thalassemia major tend to have abnormal growth and sexual maturation at puberty, presumably as a result of pituitary iron overload. This study was designed to determine whether chelation therapy with deferoxamine before the age of puberty would ameliorate this problem. METHODS: We examined 40 patients over 14 years of age with transfusion-dependent thalassemia major. The 19 patients in group A (mean [+/- SD] age at study, 17.0 +/- 1.5 years) had begun nightly treatment with subcutaneous deferoxamine before the age of 10 (mean age at start of treatment, 7.5 +/- 1.8 years). The 21 patients in group B (mean age, 24.1 +/- 3.8 years) had begun treatment after the age of 10 (mean age at start of treatment, 14.4 +/- 4.7 years). RESULTS: The abnormal findings were essentially confined to sexual development. The final height did not differ between groups or from the mean parental height in each group. Ninety percent of the patients in group A had normal sexual development, as compared with 38 percent of those in group B (P = 0.001). Outcomes were correlated with indexes of iron overload; the patients in group A had lower serum ferritin levels before chelation treatment (P = 0.01) and lower average serum ferritin levels during treatment (P = 0.005). CONCLUSIONS: Beginning chelation treatment with deferoxamine before the age of puberty can help children with transfusion-dependent thalassemia major to attain normal sexual maturation.

Adolescent↗
PubMed2005

Practical management of the intersex infant.

Intersex occurs when the appearance of the internal or external genitalia is at variance with normal development for either sex. The first question asked by, and of new parents in relation to their offspring is often "Is it a boy or a girl"? A rational approach, based on knowledge of normal prenatal sexual development, and based on a careful physical examination to guide further investigation, is required to reach a diagnosis. We briefly review prenatal sexual development to provide a background to the assessment of genital ambiguity in the newborn. Aspects of physical examination are discussed in detail, with reference to published normative data where possible. We provide a classification of genital ambiguity and an approach to differential diagnosis. We highlight some of the many syndromes associated with genital ambiguity, with reference to their genetic basis where possible. In 46,XX individuals, the commonest cause of genital ambiguity is congenital adrenal hyperplasia due to 21-hydroxylase deficiency; however, in 46,XY individuals the differential diagnosis is wide, and may remain unexplained, even after extensive investigation. Two algorithms are presented, one of which provides an initial approach based on the presence of a uterus and palpable gonads alone, and a second illustrating a comprehensive differential diagnosis of the undervirilised 46,XY individual. We discuss our approach to sharing information on the diagnosis and management with the parents and highlight the early involvement of an experienced multidisciplinary team. Finally, we consider current controversial issues relating to gender assignment and management of genital ambiguity.

Chromosome Aberrations↗
PubMed1985

Development of sexual dimorphism in human urogenital sinus complex.

The histological differentiation of the human fetal prostatic urethra and the corresponding part of human fetal female urethra was studied during the 10th through 14th weeks of ovulation age. The development of all the prostatic glands started as epithelial outgrowths from the urethral wall of the urogenital sinus during the time covered in this study. These outgrowths grew rapidly in number and size, especially the posterior ones, and no outgrowths were seen from the paramesonephric and mesonephric ducts. However, the more columnar epithelial cells on the colliculus seminalis, from which the middle and posterior lobes developed, may be of different embryonic origin, e.g. mesonephric, paramesonephric and urethral, or may react differently to hormonal factors. The possible differences in the origin and in the morphological differentiation of the epithelial cells may give clues to the differences in localization of neoplastic changes in adult prostate. The gland formation was preceded by mesenchymal changes which progressed during acinic morphogenesis. Mesenchymal cells differentiated into fibroblasts forming a lamina propria the primitive acini. The mesenchymal differentiation in the corresponding part of the female urethra was not equally prominent. However, the increase in urethral epithelial cells density and cell size was more prominent in the females. These morphological differences might be regulated by sex steroids and further strengthen the current view of the role of the mesenchyme in the prostatic morphogenesis.

Basement Membrane↗