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PubMed2004

Aquatic hypoxia is a teratogen and affects fish embryonic development.

Hypoxia occurs over large areas in aquatic systems worldwide, and there is growing concern that hypoxia may affect aquatic animals, leading to population decline and changes in community by elimination of sensitive species. For the first time, we report that sublethal levels of hypoxia can significantly increase (+77.4%) malformation in fish embryonic development. Disruption of apoptotic pattern was clearly evident at 24 h post-fertilization, which may be a major cause of malformation. Furthermore, embryonic development was delayed, and balance of sex hormones (testosterone and estradiol) was disturbed during embryonic stages, implicating that subsequent sexual development may also be affected. Overall, our results imply that hypoxia may have a teratogenic effect on fish and delay fish embryonic development, which may subsequently impair species fitness leading to natural population decline.

Animals↗
PubMed1988

Intranasal LH-RH analogue treatment of precocious puberty.

The agonistic analogues of luteinizing hormone releasing hormone were used in the treatment of precocious puberty (pp) in children. 12 children with pp were treated for 6 months with an intranasal LH-RH analogue (C6-C3-C2-naphtyl/D-alanine)-LHRH. The majority of the children had central precocious puberty. Only one child had peripheral pp. Laboratory assessment of estradiol, testosterone, LH and FSH levels revealed that 1,000 micrograms/day of this analogue diminished the hormone levels only in the group of children with central and combined pp. Bone age, pelvic ultrasound examination, sexual development and growth rate were determined pre-, during and after the treatment. The growth velocity decreased and gonadal and sexual characteristic ceased advancing after the LH-RH therapy. Biochemical and hematological studies performed in our children did not show any significant changes during the treatment periods. No adverse effects were noted from the intranasal therapy. We conclude, that intranasal therapy is safe, convenient and effective in pp, but not of peripheral origin.

Administration, Intranasal↗
PubMed1983

Developmental defects resulting from arginine auxotrophy in Aspergillus nidulans.

A mutant of Aspergillus nidulans, isolated for inability to form asexual spores (conidia) on complete medium, was found to regain the ability to conidiate if the medium was supplemented with arginine. On minimal medium the mutant required arginine for growth but at a much lower concentration than that required for conidiation. This mutant, designated argB12, thus defines a phase-critical gene, i.e. a gene whose function is in greater demand for development than for growth. In addition to its aconidial phenotype, the mutant also exhibited (depending on the medium) aberrant sexual development and a low efficiency of conidial germination. In crosses, each of these developmental phenotypes segregated with arginine auxotrophy. Genetic and biochemical analyses showed the argB12 mutation to be an allele of the previously described argB locus, mutants of which lack ornithine transcarbamylase. Arginine-requiring mutants at at least two other loci were also found to be defective in asexual sporulation, but the germination defect appears to be specific to argB mutants.

Arginine↗
PubMed1997

Chronic toxicity of environmental contaminants: sentinels and biomarkers.

Due to the use of a limited number of species and subchronic exposures, current ecological hazard assessment processes can underestimate the chronic toxicity of environmental contaminants resulting in adverse responses of sentinel species. Several incidences where sentinel species have responded to the effects of chronic exposure to ambient levels of environmental contaminants are discussed, including the development of neoplasia in fish, immunosuppression in marine mammals, pseudohermaphrodism in invertebrates, teratogenicity in amphibians, and aberrations in the sexual development of fish and reptiles. Biomarkers of chronic toxicity, including DNA mutations, alterations in specific protein and mRNA levels, and perturbations in metabolism, are presented. The incorporation of appropriate surrogate species and biomarkers of chronic toxicity into standard toxicity characterizations is proposed as a means of significantly refining the ecological hazard assessment process.

Amphibians↗
PubMed1978

LH-RH testing in men with Down's syndrome.

Males with Down's syndrome frequently present incomplete sexual development and are presumed to be sterile. The intent of this study is to clarify the aetiology of diminished sexual function in men with trisomy 21. Single dose LH-RH stimulation tests were performed in 6 men with Down's syndrome. Compared to a control group of 6 mentally retarded, institutionalized males, the subjects with Down's syndrome had markedly elevated basal FSH and slightly elevated basal LH concentrations. The FSH response to LH-RH stimulation was notably increased in the Down's syndrome group, while the LH response showed a lesser increase. Testosterone concentrations were found to be comparable in the two groups. The results are consistent with the clinical assumption that males with Down's syndrome have decreased spermatogenesis and infertility and that their Leydig cell function is less affected.

Adult↗
PubMed1999

The ultrastructure of gametogenesis of cryptosporidium baileyi (eimeriorina; cryptosporidiidae) in the respiratory tract of broiler chickens (Gallus domesticus).

The ultrastructural features of sexual development of Cryptosporidium baileyi in the respiratory tract of experimentally infected broiler chickens were studied using transmission electron microscopy. Sexual stages of C. baileyi were seen attached to the tracheal epithelium and free in the tracheal lumen. These stages included intracellular type III merozoite-like stages, microgamonts, microgametes, macrogamonts, thin-walled oocysts, and thick-walled oocysts. These stages were developmentally similar to those observed for other Cryptosporidium species. All of the above stages were observed during each study day. Thin-walled oocysts, microgamonts, and microgametes were seen less frequently than other sexual stages. Microgamonts, macrogamonts, and oocysts attached to the epithelium were all contained in a host cell membrane or within a parasitophorous vacuole. Thin-walled oocysts of C. baileyi were observed for the first time on an ultrastructural level in the respiratory tract of chickens.

Animals↗
PubMed2002

[Genetic bases of human sex determination and differentiation].

Male and female sex determination depends on Y-linked SRY gene activity. This gene initiates the cascade of reactions which lead to the differentiation of bipotential, indifferent gonads to testes or ovaries, depending on the presence or absence of active from SRY. Since SRY discovery in 1990, several new genes playing important role in gonadal and in both internal and external genitalia development and differentiation have been identified. Detailed knowledge concerning above mentioned genes will enhance our understanding of etiology of sexual development abnormalities.

Embryonic and Fetal Development↗
PubMed1987

Constitutional delay of growth and pubertal development: growth hormone secretory pattern and possible therapy.

Constitutional delay of growth and pubertal development is a frequent cause of short stature. These children have a significant retardation of skeletal age and delayed sexual development. They generally maintain a normal growth curve and tend to attain normal adult height. Although children with constitutional delay of growth are believed to have no medical or endocrine abnormality to explain their short stature, some controversy regarding their growth hormone secretory status has recently surfaced; some authors have reported low growth hormone levels to provocative stimuli and decreased growth hormone secretion during sleep, as well as low somatomedin C values in some children with constitutional delay of growth. Others, however, have found the growth hormone secretory status to be normal and similar to that of a control population. The implications of these findings, particularly in regard to possible forms of therapy, are discussed in some detail.

Adolescent↗
PubMed1979

[Hormonal desexing of boars with chlormadinone acetate].

Chloromadinone acetate produces a dependable desexualising effect on boar by contant administration in feed rations of 30 mg per die over 70 days. Sexual odour thus can be widely eliminated. Other aspects studied in a group of 107 boars are body weight development, sexual behaviour, slaughter yield, and skin quality.

Animals↗
PubMed1985

Adolescent sexuality in a therapeutic community: staff countertransference issues.

Issues connected with sexuality such as heterosexual relationships, homosexuality, sexual identity, and seductiveness, create conflict and countertransference dilemmas for staff who work with psychiatric patients in a therapeutic community. When the therapeutic community is composed of adolescents, these issues are exacerbated since sexual identity and sexual development are major concerns. The staff reacts strongly to the issue of self-determination and violation/infringement on a basic human need. These philosophical differences have their roots in countertransference feelings. Staff sometimes find it difficult to confront adolescents on emotionally charged issues that have a sexual coloring. A system is proposed for articulating and working through these feelings. A unique solution is posited for solving this conflictual attitude (based on object relations theory), whereby the residential treatment center serves as the analog of the home in order to allow adolescents to develop a sense of self before they can move on to the halfway house where heterosexual behavior is allowed (as part of the therapeutic process). This facilitates the meeting of the "self" with the "other." This procedure is explored in light of Sullivan's concept of intimacy.

Adolescent↗
PubMedDate not supplied

Basic sexual trends in the development of vertebrates.

The chain of events occurring during sexual development involves successive steps: genetic sex, gonadal sex and body sex. The latter comprises the genital tract, secondary sex characters and neural structures mediating sexual interest and appetite. Body sex obeys a hormonal control. In the absence of any hormone it develops in conformity with the homozygous sex type--feminine in mammals, masculine in birds, newts and one lizard studied so far. Similar differences have been observed for sex behaviour in some mammals and birds. It has been suggested that the sex of the gonads is determined by the presence (or absence) of the histocompatibility antigen produced by the sex chromosome of the heterozygous sex (Y or W). However, in newt or Xenopus graft chimaeras as well as in bovine freemartins, testicular dominance over presumptive ovaries is obvious whatever the mode of chromosomal control of sex. A unifying concept for sex differentiation in all vertebrates, accounting for the long series of recognized data, is still difficult to delineate.

Animals↗
PubMedDate not supplied

[Detection of endocrine pathology in children in a rural locale and the organization of their care].

As a result of the examination of 14500 children, living in the Rostov Region, data have been obtained, characterizing the level and nature of endocrine disturbance in rural children, being evaluated from such aspects as the individual physical and sexual development. Endocrine disease in the rural children (116.2 +/- 3.2%) does not exceed these abnormalities observed among the town children. The prevalence of endocrine diseases increases from 90.3 +/- 5.1% in the children, ranging in age from birth to 7 years old, to 143.2 +/- 5.3% in the schoolchildren. Girls are more often developing obesity (t = 4.2) and endocrine abnormalities (t = 4.6), whereas boys are suffering from delay of the growth (t = 3.5) and sexual maturation. The standard glucose tolerance test, performed in the children at a high risk of diabetes mellitus (with aggravated heredity in regard to diabetes mellitus and obesity of the II, III and IV stages) has revealed intolerance in 59% of the children, of whom 2.2% had diabetic type curves. Based on the data on endocrine abnormalities, a mode of the organization structure for the children's endocrinological service was developed.

Adolescent↗
PubMed1992

Transforming growth factor-alpha gene expression in the hypothalamus is developmentally regulated and linked to sexual maturation.

Hypothalamic injury causes female sexual precocity by activating luteinizing hormone-releasing hormone (LHRH) neurons, which control sexual development. Transforming growth factor-alpha (TGF-alpha) has been implicated in this process, but its involvement in normal sexual maturation is unknown. The present study addresses this issue. TGF-alpha mRNA and protein were found mostly in astroglia, in regions of the hypothalamus concerned with LHRH control. Hypothalamic TGF-alpha mRNA levels increased at times when secretion of pituitary gonadotropins--an LHRH-dependent event--was elevated, particularly at the time of puberty. Gonadal steroids involved in the control of LHRH secretion increased TGF-alpha mRNA levels. Blockade of TGF-alpha action in the median eminence, a site of glial-LHRH nerve terminal association, delayed puberty. These results suggest that TGF-alpha of glial origin is a component of the developmental program by which the brain controls mammalian sexual maturation.

Animals↗
PubMed1980

Etiology of homosexuality.

The range of expression of homosexuality and its association with certain cultural, environmental, and genetic factors are most consistent with the concept of a multifactorial trait. Additionally, genetic heterogeneity in this phenotype (alternative mutants corresponding to a single phenotype) is highly probable. In certain nonhuman and presumably in human species the normal sexual development of the hypothalamus is guided by an appropriate exposure to androgen at a critical early stage, and this in turn presumably contributes to sociopsychologic sex development. Particularly instructive in this regard have been the monogenic experiments of nature in man--XY females with insensitivity to androgens, congenital adrenal hyperplasia, and male pseudohermaphrodites (5-alpha-reductase deficiency). Additionally, in the human, sociopsychologic sex also appears to be molded by sex assigned at birth and sex of rearing. Several of the intersexuality syndromes and psychoses are accompanied by increased homosexuality, but a majority of homosexuals are not in these categories. A limited number of family studies, including twins, tentatively suggests a heritable risk, at least in some families.

Animals↗
PubMed1984

Precocious puberty in myelomeningocele patients.

Of a group of 79 patients (45 males, 34 females) with myelomeningocele (MMC), 52 had associated hydrocephalus. Three of the hydrocephalic patients (two arrested and one shunted) were found to have precocious sexual development. Endocrine investigations confirmed true isosexual precocity. Hydrocephalus is known to be associated with precocious puberty, but the occurrence of sexual precocity in patients with hydrocephalus in conjunction with MMC has not been described to date. As the clinical diagnosis of hydrocephalus in a young child is often unreliable, routine computerized tomographic scans of all MMC patients is advised, and even patients with arrested hydrocephalus should be followed carefully for signs of precocious puberty. In addition, a high incidence (15%) of cryptorchidism was found in the group of MMC patients reviewed.

Child↗
PubMed2000

Local mechanisms in sex specific morphogenesis.

Sex determination in mammals occurs on three levels. Segregation of sex chromosomes determines the chromosomal sex. Sry on the Y chromosome induces formation of a testis which in turn regulates via AMH and testosterone the development of the genital tract and the external phenotype. Recently a number of new factors have been described, which affect sexual development but have not yet found a place in the above canonical scheme of sex determination. For the purpose of this review, the factors are aligned according to their quality as transcription factors, steroid hormones, or growth factors. In this web of regulatory factors, the classical sex determining factors have evolved as master mechanisms while others function as slaves, or were totally suppressed. In this context, androgens acquired a dominant role in mammalian development. Androgens determine the morphogenesis of the genital tract. The effects of androgens are mediated by local cellular interactions. In the cranial section of the Wolffian duct the androgen receptor appears in the epithelium and mediates maintenance of the duct via an epithelial factor. In the caudal section of the duct the androgen receptor is expressed in the embryonic mesenchyme. Vesicular glands are induced via a morphogenetically active mesenchymal condensation, while the epithelial buds are primarily AR androgen receptor negative. The dominant role of androgens and formation of a vagina evolved together at the transition to eutherian mammals. Under this aspect, the role of androgens in the development of the vagina is analyzed.

Androgens↗
PubMed1987

Male hypothalamic hypogonadism: induction of spermatogenesis by subcutaneous pulsatile gonadotrophin-releasing hormone.

Six male patients (aged 21-34 years) with isolated hypothalamic hypogonadism were given subcutaneous pulses of gonadotrophin-releasing hormone every 90 min for 14-74 weeks. The therapy produced an increase in testicular volume (4 patients) and a rise in serum luteinizing hormone, follicle-stimulating hormone, and testosterone levels in every patient. Motile sperm developed in 3 patients after a mean of 17 weeks, but were not seen in other patients who were less sexually developed after a mean of 31 weeks of therapy. Computerized tomography scans of the pituitary fossa revealed an empty sella in 4 patients and a partially empty sella in 2. Subcutaneous pulsing of gonadotrophin-releasing hormone is a simple and safe way of inducing spermatogenesis, but it is more likely to be successful in patients whose pubertal development is otherwise near completion. Previous human chorionic gonadotrophin and/or testosterone treatment does not interfere with and may benefit subsequent gonadotrophin-releasing hormone therapy.

Adult↗
PubMed2001

Decreased expression of IGF-II and its binding protein, IGF-binding protein-2, in genital skin fibroblasts of patients with complete androgen insensitivity syndrome compared with normally virilized males.

The action of androgen by way of the AR is required for the development of male gonads and external genitalia. The interplay between androgens and the somatotropic axis, in particular the IGFs in sexual development, is currently under thorough investigation. The IGF system is thought to mediate the androgen action in androgen-responsive cells. To investigate the interaction of androgens with the IGF system, we compared the expression of IGFs and IGF-binding proteins in cultured genital skin fibroblasts from nine patients with the syndrome of complete androgen insensitivity with that in genital skin fibroblasts from 10 normally virilized males. Mutations in the AR gene and/or abnormalities of the AR protein in the immunoblot were detected in all complete androgen insensitivity genital skin fibroblast strains. They caused a complete failure of DHT binding. RIA and RT-PCR demonstrated that the genital skin fibroblast strains expressed IGF-II, IGF-binding protein-2, and IGF-binding protein-3, but no IGF-I. Most strikingly, complete androgen insensitivity genital skin fibroblast strains produced significantly lower IGF-II (P < 0.001; 42.2 +/- 9.7 vs. 106.9 +/- 11.8 ng/mg protein) and IGF-II mRNA (P < 0.01, by RT-PCR) than control genital skin fibroblast strains. The production of IGF-binding protein-2 was also decreased (P < 0.03) in complete androgen insensitivity genital skin fibroblasts, whereas that of IGF-binding protein-3 did not differ. Furthermore, high levels of IGF-binding protein-5 mRNA were detected in all genital skin fibroblast strains, whereby the 28-kDa band in the ligand blot, probably representing IGF-binding protein-5, was more abundant in complete androgen insensitivity genital skin fibroblasts. Exposure of the genital skin fibroblasts to T (5 x 10(-8) M) had only weak effects on the expression of IGFs and IGF-binding proteins. In conclusion, although the mechanism underlying these differences requires further study, it is conceivable that in addition to the endocrine actions of IGF-I, IGF-II and IGF-binding protein-2, as local growth factors, are involved in the mediation of androgen action and growth of genital tissues.

Androgen-Insensitivity Syndrome↗