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PubMed1986

Determinants of sexual and dating behaviors among adolescents.

The study of adolescent sexual development has typically focused on the incidence and age of onset of particular behaviors. Recent developments in the analysis of covariance structures permit more powerful simultaneous tests of the determinants of adolescent sexual behavior. These new methods allow the assessment and evaluation of the interrelatedness between unobserved, latent constructs. Data were obtained from 183 males and 193 females ranging in age from 12 to 18 years old, selected from three birth cohorts using a stratified random sample. Eight latent constructs--Sexual and Dating Involvement, Self-Acceptance, Feminist Sex Role Attitudes, Deviant Social Network, Importance of Dating, Lack of Heterosexual Competence, Sexually Active Social Network, and Stressful Change Events--were hypothesized to explain the variance in 26 observed variables. Several causal models were tested that specified structural relationships among the latent constructs. A theoretically meaningful model was arrived at that linked the eight, error-free factors.

Adolescent↗
PubMed2006

Effects of environmentally relevant concentrations of atrazine on gonadal development of snapping turtles (Chelydra serpentina).

The herbicide atrazine has been suspected of affecting sexual development by inducing aromatase, resulting in the increased conversion of androgens to estrogens. We used snapping turtles (Chelydra serpentina), a species in which sex is dependent on the production of estrogen through aromatase activity in a temperature-dependent manner, to investigate if environmentally relevant exposures to atrazine affected gonadal development. Eggs were incubated in soil to which atrazine was applied at a typical field application rate (3.1 L/ha), 10-fold this rate (31 L/ha), and a control rate (no atrazine) for the duration of embryonic development. The incubation temperature (25 degrees C) was selected to produce only males. Although some males with testicular oocytes and females were produced in the atrazine-treated groups (3.3-3.7%) but not in the control group, no statistical differences were found among treatments. Furthermore, snapping turtle eggs collected from natural nests in a corn field were incubated at the pivotal temperature (27.5 degrees C) at which both males and females normally would be produced, and some males had oocytes in the testes (15.4%). The presence of low numbers of males with oocytes may be a natural phenomenon, and we have limited evidence to suggest that the presence of normal males with oocytes may represent a feminizing effect of atrazine. Histological examination of the thyroid gland revealed no effect on thyroid morphology.

Animals↗
PubMed1993

Molecular cloning and characterization of two genes encoding gp138, a cell surface glycoprotein involved in the sexual cell fusion of Dictyostelium discoideum.

The sexual development of cellular slime molds is initiated by acquisition of sexual fusion competence of myxamoeboid cells. During the acquisition of fusion competence in NC4 and HM1 strain cells of Dictyostelium discoideum, opposite in mating types, a glycoprotein gp138, relevant to sexual cell fusion, is expressed on the cell surfaces of both the strains. To investigate the mechanisms controlling cell fusion, gp138 was purified and its N-terminal amino acid sequence was determined. An oligonucleotide with sequence predicted from the amino acid sequence was synthesized to isolate the gene encoding gp138. Two genes, referred to as GP138A and GP138B, were then cloned. They contain the region which encodes the N-terminal amino acid sequence of the gp138 protein and their structure is very similar on the whole. The C-terminal portion of the predictive polypeptides produced by the genes is highly hydrophobic and proline rich. It has homology with a portion of gp80, a glycoprotein for cell-cell adhesion, and PsA, a glycoprotein specific for prespore cells, reported previously in D. discoideum. The expression of GP138A is greater than that of GP138B. The mRNA of GP138A is expressed at the time of acquisition of fusion competence of cells during cultivation but the mRNA of GP138B is not.

Amino Acid Sequence↗
PubMed1995

Chronic neuroendocrinological sequelae of radiation therapy.

A variety of neuroendocrine disturbances are observed following treatment with external radiation therapy when the hypothalamic-pituitary axis (HPA) is included in the treatment field. Radiation-induced abnormalities are generally dose dependent and may develop many years after irradiation. Growth hormone deficiency and premature sexual development can occur following doses as low as 18 Gy fractionated radiation and are the most common neuroendocrine problems noted in children. Deficiency of gonadotropins, thyroid stimulating hormone, and adrenocorticotropin are seen primarily in individuals treated with > 40 Gy HPA irradiation. Hyperprolactinemia can be seen following high-dose radiotherapy (> 40 Gy), especially among young women. Most neuroendocrine disturbances that develop as a result of HPA irradiation are treatable; patients at risk require long-term endocrine follow-up.

Adrenocorticotropic Hormone↗
PubMed1998

Staff perceptions of sexuality-related problems and behaviors of psychiatrically hospitalized children and adolescents.

Clinical staff at two hospitals serving children and adolescents were surveyed regarding their observations and experiences regarding the sexuality-related behaviors and issues of patients. Results of this descriptive study indicate that staff frequently encounter a wide range of such problems, including the effects sexual abuse, sexually aggressive or inappropriate behavior, lack of knowledge about basic hygiene and sexual development, pregnancy and contraception, high-risk behaviors, and sexually-transmitted diseases, including AIDS. Similarities and differences of the perceptions by staff of these problems are compared across unit types (children's, adolescents, dually-diagnosed, developmentally-disabled). Implications for staff training, clinical policies, and further research are discussed.

Adolescent↗
PubMed2005

Effects of juvenile hormone analogs on new reproductives and colony growth of Pharaoh ant (Hymenoptera: Formicidae).

Two juvenile hormone analogs (JHAs), pyriproxyfen and S-methoprene, were impregnated into dried tuna fish and fed to colonies of Monomorium pharaonis (L.) at very low concentrations (1.0, 2.0, 3.0, 4.0, and 5.0 microg/ml). Its effects on the production of sexuals and colonial growth were observed. Colonies treated with pyriproxyfen yielded sexuals with physical abnormalities. Both female and male sexuals developed bulbous wings, decreased melanization, and died shortly after emergence. Sexuals emerged from colonies treated with S-methoprene did not possess anomalous characteristics. Both pyriproxyfen and S-methoprene did not have significant effects on colonial growth because of the low concentrations of the baits. A commercial bait containing 0.3% S-methoprene (Bioprene-BM) also was evaluated for its efficacy on Pharaoh's ant colonies. Results showed that Pharaoh's ant colonies succumbed to the lethal effects of S-methoprene. Colony members were reduced significantly. Production of queens also decreased significantly in treated colonies and treated queens were unable to lay eggs. JHAs are slow acting and eliminate ant colonies at a relatively slow rate. At low concentrations, pyriproxyfen recorded baffling results, i.e., bulbous wings and demelanized exoskeleton, and it is vital that further studies are initiated to solidify these findings.

Animals↗
PubMed2004

Couple characteristics and outcome of therapy in vaginismus.

OBJECTIVE: To describe couple characteristics and outcome of therapy in vaginismus. DESIGN: A prospective before-after intervention descriptive study. SETTING: Department of Physiology, Faculty of Medicine, Colombo, Sri Lanka. METHODS: Fifty six couples with vaginismus, mostly self referrals and referrals from gynaecologists and general practitioners, were treated with a standard cognitive behaviour therapy protocol with before-after assessments of the degree of vaginismus and individual partner self-ratings of the relationship and psychological status (GHQ-30). OUTCOME MEASURES: Success at the end of the therapy was equated to the absence of or only mild vaginismus and, improvement in the couple relationship and psychological status scores. RESULTS: Twenty seven (48%) of the 52 (93%) couples with non-consummation reported failure of coitus following previous non-surgical and surgical interventions. Love marriages (70%), frequent attempts at sex (75%, 3 or 4 times/week) and sexual arousal (women = 86%, men = 89%) characterised couples. Ten men developed sexual problems, mostly erectile failure and premature ejaculation secondarily. Couple therapy enabled penetrative sex in 45 (80.3%). The single prognostic indicator of outcome was the degree of vaginismus at first visit, those with mild and moderate vaginismus (77%) being significantly more likely to establish coitus (p<0.001) and complete the therapy (p<0.001). The couple relationship improved marginally (women p<0.01, men 0.025 0.01) but the psychological status remained unchanged. Dropouts and referrals for psychiatric and marital counselling failed to complete therapy. INTERPRETATION: Couple sex therapy is effective in the management of vaginismus. Health professionals, especially gynaecologists and general practitioners, need to be aware of the problem and the satisfactory outcome of sex therapy.

Adult↗
PubMed1999

Sildenafil for iatrogenic serotonergic antidepressant medication-induced sexual dysfunction in 4 patients.

OBJECTIVE: To evaluate the effect of sildenafil on iatrogenic serotonergic antidepressant-induced sexual dysfunction. METHOD: Four outpatients (2 men, 2 women) who developed sexual dysfunction (erectile impotence, anorgasmia) during treatment with a serotonin reuptake inhibitor antidepressant for psychiatric disorder were selected. Each subject was initially prescribed sildenafil 50 mg to be taken approximately 1 hour before sexual activity. The dose was increased to 100 mg for a partial or failed response. RESULTS: Four cases are detailed in case report fashion. All 4 had rapid reversal of their sexual dysfunction, usually with the first dose. Reversal equates to 1 successful use of sildenafil in each of 2 patients and 3 uses in 2 patients. CONCLUSION: Sildenafil may be an effective treatment for serotonergic antidepressant-induced sexual dysfunction and deserves further evaluation in randomized placebo-controlled studies.

Adult↗
PubMed2002

Application of Megan's law to juveniles.

This article examines (a) the history of registration and notification statutes for sex offenders and the concerns and legal challenges they have faced, (b) psychology's limited knowledge about normal versus abnormal sexual development, and (c) research that suggests rates of recidivism for sexual offenses may be lower for juveniles than for adults who have been discovered and received punishment and/or treatment. Although the behaviors of juvenile and adult sex offenders may appear similar, the underlying mechanisms triggering the behaviors may be different or juveniles' patterns of behaviors may be less established, accounting for some of the observed differences in recidivism rates. Although the authors recognize the critical objective of protecting victims and potential victims, this article focuses on intervention efforts with juvenile sex offenders.

Adolescent↗
PubMedDate not supplied

Evaluation of interspecific hybrids of the chicken, guinea fowl, and Japanese quail for innate resistance to coccidia.

Experimental chicken/guinea fowl hybrids, guinea fowl, and chickens were orally inoculated with Eimeria acervulina or E. tenella, which are specific for chickens, or with E. grenieri, which is specific for guinea fowl. No intact oocysts were found in feces within 24 hr of inoculation, suggesting that excystation occurred in the normal and abnormal hosts. No oocysts were found in the feces of hybrids during a 9-day postinoculation period. The guinea fowl passed oocysts of guinea fowl coccidia (E. grenieri) but not those of chicken coccidia, and the chickens passed oocysts of chicken coccidia (E. acervulina and E. tenella) but not those of guinea fowl coccidia. Some asexual development (schizogony) occurred in hybrids inoculated with E. tenella, but sexual development (gametogony) did not. In contrast, quail/chicken hybrids became infected with oocysts of chicken coccidia (E. acervulina, E. tenella, and E. maxima) and quail coccidia (E. bateri) and passed a few oocysts during the normal patent period; control chickens and quails became heavily infected with oocysts of chicken and quail coccidia, respectively.

Animals↗
PubMed1980

Reproductive dysfunction in male rats following prenatal exposure to phenobarbital.

The effect of prenatal exposure to phenobarbital (40mg/Kg/day from day 12 to day 19 of pregnancy) on sexual development of male offspring was investigated. Anogenital distance of the male offspring exposed to phenobarbital was significantly smaller. Testicular descent was delayed by 1-3 days, but the age of onset of puberty did not change. Fertility was reduced significantly (P less than .05) in phenobarbital exposed animals compared to that of control. Upon sacrifice, the weight of the seminal vesicles of treated rats was smaller compared to control, but the weight of liver was increased. Hormone measurement in adult age showed a significant reduction in both testosterone and luteinizing hormone levels in the phenobarbital exposed males. Moreover, prenatal treatment with phenobarbital produced an elevated level of cytoplasmic androgen receptor in the seminal vesicles of the adult rats. These findings suggest that phenobarbital treatment during prenatal development can produce some permanent alterations in the process of sexual maturation.

Animals↗
PubMed1993

Germ cell deficient (gcd) mouse as a model of premature ovarian failure.

Premature ovarian failure (POF) in women is characterized as menopause commencing before age 35. Although some cases of POF appear to be inherited, no experimental animal models of familial POF are available. Recently a mouse mutation has been identified that results in infertility due to a lack of primordial germ cells arising in early embryonic development. It was observed that shortly after puberty, females homozygous for this mutation entered reproductive senescence as defined by high levels of circulating gonadotropins, inability to respond either hormonally or functionally to superovulation, and a disrupted estrous cycle. Also, the ovaries completely lacked developing follicles and the endometrium was inactive. However, these mice had undergone complete sexual development as determined by age of vaginal opening, mammary gland histology, and sexual behavior. Thus, these animals closely mimic familial premature ovarian failure and may be useful models for study of the pathogenesis and treatment of this condition.

Animals↗
PubMed1987

Treatment of pregnant rhesus macaques with testosterone propionate: observations on its fate in the fetus.

Castrated male primates, unlike castrated male rodents, respond to exogenous estrogen by releasing gonadotropin. Although this disparity is unexplained, it may occur because the amount of testicular androgen secreted during a critical period for sexual differentiation is not sufficient to completely androgenize the anlagen of the central nervous system (CNS) in male primates. Therefore, male primates might be incompletely masculinized, and if fetal males were exposed to additional androgen during sexual development, they would no longer display the positive feedback to estrogen that usually characterizes females. Besides the development of mechanisms mediating the release of gonadotropins, questions about relationships between adult male sexual behaviors and the intensity of the androgen stimulus upon developing neural structures are of interest. We tested some of these possibilities by injecting androgen into 8 pregnant rhesus macaques from Days 40 through 50 of gestation, and we compared serum levels of testosterone (T), dihydrotestosterone (DHT), and androstenedione (delta 4) in the fetal circulation with that of 5 untreated control males. Fetal sera (both male and female) from treated pregnancies did not contain significantly greater quantities of T and DHT than sera of intact control males from untreated mothers. The maternal sera, however, contained large amounts of T (125.05 +/- 27.40 [SEM] ng/ml, n = 8) and significant elevations of DHT and delta 4 after treatment. The concentrations of delta 4 in the fetal circulation were significantly elevated (p less than 0.01) in treated fetuses compared to intact control males, probably due to the actions of the 17 beta-hydroxysteroid dehydrogenases in the placenta, the fetus, or both.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Molecular characterization of postnatal development of testicular steroidogenesis in luteinizing hormone receptor knockout mice.

We recently demonstrated that the sexual development of LH receptor (LHR) knockout mice is normal until birth, but is totally arrested thereafter. To study further the functional defects of LHR knockout mice, the expression of selected Leydig cell-specific genes was studied in (-/-) and control (+/+) mice between birth and adulthood. Testis weights were similar at birth in both types of mice, but after about 3 wk, the (-/-) testes remained significantly lighter, weighing only 18% of (+/+) testes on d 70. Testicular testosterone (T) content on d 1 was also similar in (-/-) and (+/+) testes, but it was 97% reduced by d 70 in the former. Likewise, testicular T production in vitro was similar in neonatal (-/-) and (+/+) testes, but became undetectable in adult (-/-) testes. The mRNA expression of cytochrome P450 side-chain cleavage, 17 alpha-hydroxylase cytochrome P450, 17 beta-hydroxysteroid dehydrogenase type III, 3 beta-hydroxysteroid dehydrogenase I (3 beta HSDI), steroidogenic acute regulatory protein, and relaxin-like factor were similar in newborn (-/-) and (+/+) testes, but became gradually very low/undetectable in (-/-) mice. The only exception was the persistently high expression of 3 beta HSDI in peritubular Leydig precursor and mesenchymal cells of the (-/-) testes at all ages. Immunohistochemistry and Western hybridization studies confirmed the above findings. In conclusion, LH action is not essential for the differentiation and function of mouse fetal Leydig cells, but, with the exception of 3 beta HSDI, the expression of the key genes of endocrine function of adult Leydig cells is dependent on LH signaling.

3-Hydroxysteroid Dehydrogenases↗
PubMed1990

Intersex and genital ambiguity.

Normal sexual differentiation in males and females is described. Discussion of disorders of abnormal sexual development is confined to those producing genital ambiguity. Genital ambiguity is further subdivided into disorders of gonadal development and disorders of fetal endocrinology. Disorders of gonadal development with abnormal sex chromosome constitution include those with and without sexual ambiguity. Only those producing sexual ambiguity, true hermaphroditism and mixed gonadal dysgenesis are discussed further. Disorders of fetal endocrinology are divided into female and male pseudo hermaphroditism. The main features of each are highlighted. A practical method of management of patients with ambiguous genitalia then follows.

Disorders of Sex Development↗
PubMedDate not supplied

Pisrt1, a gene implicated in XX sex reversal, is expressed in gonads of both sexes during mouse development.

XX sex reversal syndromes not involving Sry provide an opportunity to identify and study genes important for sexual development. The polled intersex syndrome (PIS) in goats, which shares some features with blepharophimosis, ptosis, epicanthus inversus syndrome (BPES) in humans, exemplifies such syndromes. BPES is caused by defects in the forkhead transcription factor gene FOXL2, while PIS is caused by a large deletion of goat chromosome 1q43 that affects transcription of the genes Pisrt1 and Foxl2. Pisrt1 is a non-translated gene that has a sexually dimorphic expression pattern in goats. Here, we describe the structure and expression of the mouse Pisrt1 locus, to investigate its likely role in ovarian development more broadly in mammals. This gene showed some sequence similarity, and was found in a similar genomic context, to its goat and human orthologues. Expression analyses indicated that Pisrt1 is transcribed, and its mRNA polyadenylated and exported to the cytoplasm, but no significant open reading frames were found in a 1.5kb mouse genomic region corresponding to goat Pisrt1. Pisrt1 transcripts were expressed very broadly among tissues of the developing mouse embryo, and at similar levels in male and female gonads at each stage examined, as determined by in situ hybridisation and RT-PCR. This profile of expression suggests that Pisrt1 is unlikely to contribute to sex-specific events during gonadal development in mice and that divergent pathways of ovarian development operate among different mammalian species.

Animals↗
PubMed2000

Adolescents' sexual media diets.

A model of how adolescents choose, interpret, and interact with the mass media is discussed in the context of sexual development. The Media Practice Model suggests that adolescents select and react to sexual media diets that speak to an emerging sense of themselves as sexual human beings. Relatively little is known about how the sexual content adolescents attend to in the media is interpreted or incorporated into their lives. Entertainment-education and media literacy are two strategies for increasing the possibility of healthy outcomes from adolescents' use of sexual media.

Adaptation, Psychological↗
PubMed1981

[The change of hypothalamic-pituitary-ovarian function during peripubertal period in female baboons (author's transl)].

To clarify the relationship between the change in plasma levels of pituitary and ovarian hormones and the development of hypothalamic-pituitary-ovarian function in the course of sexual maturation, longitudinal studies were performed using seven peripubertal female baboons (Papio cynocephalus). Serial blood samples were collected every two weeks from 12 months before menarche to 8 months after menarche. Plasma levels of prolactin, LH, FSH and estradiol were determined by specific radioimmunoassay methods. Periodic injections of synthetic LHRH (100 microgram) + TRH (500 microgram) and conjugated estrogen (Premarin 20mg) at one month interval were also conducted throughout the period studied. Furthermore, daily blood samples were drawn from two baboons from the first day of menarche up to the subsequent onset of vaginal bleeding, and the fluctuations of the same kinds of plasma hormonal levels were analysed. The basal plasma levels of FSH showed the earliest significant increase seven months prior to menarche, while those of LH, prolactin and estradiol exhibited no apparent change. Statistically significant elevations of basal plasma LH, prolactin and estradiol levels were observed one month before menarche. Intravenous injections of LHRH which were given earlier than two months before menarche induced marked responses in FSH with limited changes in LH patterns. After this stage of puberty, the response of LH stimulated by LHRH administrations were augmented progressively, whereas those of FSH became impaired. The peak values of prolactin after TRH injections increased, obviously around the same period of sexual development. The LH positive feedback induced by Premarin was observed one month before menarche in four baboons whose LH responses were exaggerated significantly by LHRH, and the sex skin reached turgidity to a certain extent. The evaluation of the hormonal changes during the first menstrual cycles after menarche indicated that the follicular phases were prolonged due to delayed elevation of FSH during the early follicular phase, and the length of the luteal phases were shorter in comparison to those seen in the normal ovulatory cycles of adult baboons. The results from the present longitudinal studies on baboons revealed characteristic changes accompanied by the maturation of the hypothalamic-pituitary-ovarian function during the peripubertal period. The initial change was the increase of basal FSH levels, which was caused by the alteration of hypothalamic sensitivity to endogenous estrogen, and that FSH stimulated the ovary to secrete estrogen. The increased basal estradiol secretion influenced both hypothalamic and pituitary functions, namely, the dominant gonadotropin secretion by the pituitary shifted from FSH to LH, a positive feedback mechanism was established, and prolactin level secretions with enhanced response after TRH stimulations were increased. This sequence of events indicates that hypothalamic-pituitary-ovarian interaction occurs during maturation in the peripubertal period.

Animals↗