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PubMed1999

Developmental changes of hypothalamic, pituitary and striatal tachykinins in response to testosterone: influence of prenatal melatonin.

Substance P (SP) and neurokinin A (NKA), members of the family of mammalian tachykinins, are involved in the regulation of many physiological functions and are widely distributed in mammalian tissues. In this report, the effects of prenatal melatonin on the postnatal developmental pattern of NKA, and SP, and on testosterone secretion were investigated. Also, tachykinin response to the administration of testosterone propionate (TP) was studied. The brain areas studied were medio-basal-hypothalamus, pituitary gland and striatum. Male rat offspring of control or melatonin treated mother rats were studied at different ages of the sexual development: infantile, juvenile or prepubertal periods, and pubertal period. Both groups received exogenous TP (control-offspring+TP and MEL-offspring+TP), or the vehicle (control-offspring+placebo and MEL-offspring+placebo). Hypothalamic concentrations of all peptides studied in control-offspring+placebo remained at low levels until the juvenile period, days 30-31 of age. After this age, increasing concentrations of these peptides were found, with peak values at puberty, 40-41 days of age, then declining until adulthood. In the MEL-offspring+placebo a different pattern of development was observed; hypothalamic concentrations of NKA and SP from the infantile period until the end of juvenile period were significantly higher than in control-offspring+placebo. TP administration exerted a more marked influence on MEL-offspring than on control-offspring and prevented the elevation in tachykinin concentrations associated with prenatal melatonin treatment. TP administration to control-offspring resulted in significantly reduced (P < 0.05) tachykinin concentration only at 40-41 days of age, and increased (P < 0.01) during infantile period as compared to control-offspring+placebo. Pituitary NKA concentrations were lower than in the hypothalamus. In control-offspring+placebo pituitary NKA levels did not show significant changes throughout sexual development. A different developmental pattern was observed in MEL-offspring+placebo, with significantly increased (P < 0.05) pituitary NKA concentrations at 35-36 days of age than in control-offspring+placebo. TP administration to control-offspring influenced pituitary NKA levels at the end of the infantile and pubertal periods, showing at both stages significantly higher (P < 0.05) NKA levels as compared to control-offspring+placebo. NKA levels in MEL-offspring+TP were only affected at 21-22 days of age, showing significantly increased (P < 0.01) values as compared to MEL-offspring+placebo. Striatal tachykinin concentrations in control-offspring did not undergo important modifications throughout sexual development, but during the prepubertal period they started to increase. Maternal melatonin and TP injections produced short-lived alterations during the infantile period. The results showed that prenatal melatonin delayed the postnatal testosterone secretion pattern until the end of the pubertal period and postnatal peptide secretion in brain structures. Consequently, all functions depending of the affected areas will in turn, be affected.

Animals↗
PubMed1995

A framework to develop a sexual abuse prevention program.

In 1993, the Province of Ontario proclaimed the Regulated Health Professions Act (RHPA) and 21 health profession acts, including the Medical Radiation Technology Act. Under the RHPA, 21 health care regulatory colleges were created to ensure that Ontario patients receive safe, competent and quality care. Programs administered by the colleges ensure that all patients are treated with dignity and respect, and include measures for preventing or dealing with the sexual abuse of patients. This article sets out a framework and discusses issues related to the development and implementation of a sexual abuse prevention program. Key components include: establishing a patient-relations committee, preparing a statement of philosophy, defining sexual abuse, setting guidelines for professional behaviour, and educating members, staff and the public. Other aspects of such programs include procedures for complaints and discipline, mandatory reporting and penalties, and funding for therapy and counselling for patients who have been sexually abused by members.

Communication↗
PubMed2006

Development and sexual maturation of Echinococcus granulosus adult worms in the alternative definitive host, Mongolian gerbil (Meriones unguiculatus).

In the present study for the first time an alternative definitive host model has been established for the complete development of Echinococcus granulosus in Meriones unguiculatus (Mongolian gerbils) up to shelled eggs production, as happened in the natural host. Animals treated with methylprednisolone acetate were orally inoculated with approximately 3000 protoscoleces and the development of parasites in the small intestine observed up to 46 days post-infection (p.i.). The cestodes survive, strobilate, mature sexually and complete their development in the intestine up to production of shelled embryonated eggs containing fully formed six-hooked oncospheres, similarly to the natural canid host (stage 7 by Smyth). Shelled eggs are first observed in the rodent/E. granulosus model at 44 days p.i. Somatic growth in gerbils appears to follow a similar trend to dogs, length increasing to over 3mm at 44 days p.i., while, compared to the natural host, organogenesis is observed only to progress at a slower rate in the early developmental stages. Parasite burden was found to vary among non-inbred animals and developmental stages of worms recovered from the same animal differed widely. Worm localisation follows the pattern observed in the natural host, the parasites appearing for the most part distributed in the proximal third of the small intestine. The development of alternative definitive hosts may facilitate research in this field, overcoming legislative impediments that restrict the use of dogs for experimental purposes.

Animals↗
PubMed1991

Stimulation of gonadal development by sexual interaction of pubertal African catfish, Clarias gariepinus.

Stimulation and inhibition of gonadal development by intersexual contact was studied in pubertal African catfish, Clarias gariepinus. The effect of a possible interaction was studied by evaluation after a 98-day experimental period of gonadal development in combinations of intact and anosmic males and females. In addition, separate groups of males and females, respectively, were exposed to holding water from these combinations. A tentative model of stimulation of gonadal development by intersexual contact in pubertal fish was developed. Males stimulate ovarian development of females by both olfactory and tactile cues. In addition, males seem to enhance gonadal development of other males through olfactory stimulation via holding water. In contrast, females tended to inhibit male gonadal development, especially through tactile cues. It seems that although males are hampered by female tactile stimuli in their gonadal development and ability to stimulate male gonadal development, their ability to stimulate female gonadal development is not affected.

Animals↗
PubMed2004

Cloacal gland and testes development in male Japanese quail selected for divergent adrenocortical responsiveness.

The time course of sexual development in male quail from lines selected for either a reduced (low stress, LS) or an exaggerated (high stress, HS) plasma corticosterone response to brief restraint was determined. Sexual development was assessed by examination of cloacal gland area (CAREA) and volume (CVOL), proportion of individuals that produced cloacal gland foam, and the intensity of cloacal gland foam production (CFP) at 4, 5, 6, 8, 10, 14, and 16 wk of age. These intervals encompass ages during which growing, photostimulated quail would be expected to evolve from being totally prepubescent to well into adulthood. Testes weight (TW) and the proportion of individuals that had achieved a combined TW of 500 mg (PI500) were also measured at 6 and 16 wk of age. Mean CAREA and CVOL were similar in LS and HS quail at 4 wk of age. Beginning at 5 wk of age and thereafter, CAREA was greater (P < 0.05) in LS than in HS quail. Similarly, beginning at 6 wk of age and thereafter, CVOL was greater (P < 0.05) in LS than in HS quail. More LS than HS birds also expressed foam at 4 (P < 0.05), 5 (P = 0.15), and 6 wk (P < 0.05) of age. From 8 wk on, all birds were in foam production. CFP results mimicked those found for CAREA and CVOL in that LS quail tended toward higher CFP values than HS quail at all intervals of measurement. TW were higher (P < 0.02) in LS than HS quail when data from the 2 ages at which testes were harvested were combined. At 6 wk of age, the LS and HS birds showed a PI500 line difference (P < 0.08) of 1.0 and 0.91, respectively; by 16 wk, all birds exhibited a maximum PI500. The results suggest that 1) selection for reduced adrenocortical responsiveness in Coturnix is accompanied by an accelerated onset of puberty in males, and 2) enhanced reproductive development in LS males remains extant throughout early to middle-age adulthood.

Adrenal Cortex↗
PubMed1999

Development of sexually dimorphic vasotocinergic system in the bed nucleus of stria terminalis in chickens.

The bed nucleus of stria terminalis (BnST) of the domestic fowl contains two groups of parvicellular vasotocinergic neurons that are sexually dimorphic. In adult cockerels, arginine vasotocin (AVT) synthesis is well expressed in the dorsolateral and ventromedial portions of the BnST, whereas in corresponding brain areas of hens, AVT synthesis is completely lacking. In the present study, in situ hybridization and immunocytochemical methods were used to compare the ontogeny of sexually dimorphic AVT gene expression in the BnST of male and female chickens from day 12 of embryonic development (E12) until the onset of sexual maturation. By E12, both parvicellular groups of AVT-immunoreactive (AVT-ir) perikarya in the developing BnST can be distinguished in some males, whereas in females their presence is questionable. A quantitative analysis, beginning at E14, showed that the parvicellular dorsolateral portion of the BnST of male embryos had more AVT perikarya compared with females. In contrast, no evident sex difference in distribution pattern and number of AVT mRNA containing neurons in this BnST portion was observable by in situ hybridization at E15. At E18, as well as on the first and second days posthatch (D1 and D2), no differences in the number of AVT synthesizing cells and intensity of immunoreactive staining in male versus female chickens were found. Between D2 and D7, the number of AVT-ir cells in the BnST declined rapidly in both sexes until it disappeared completely in females before D35. In males, another increase in sexually dimorphic AVT-ir cells and innervation of the lateral septum was associated with the onset of puberty and fully matched a pattern observed in adult fowls. These results demonstrate that the sexually dimorphic part of the AVT system undergoes sexual differentiation during early stages of ontogeny.

Animals↗
PubMed1987

Sexually dimorphic development of cholinergic enzymes in the rat septohippocampal system.

Cholinergic enzyme activity is sexually dimorphic in the rat hippocampal formation. Acetylcholinesterase (AChE) activity is greater in females than males in Ammon's horn/subiculum on the day of birth, but is equivalent in males and females at all older ages, suggesting an earlier maturation. Choline acetyltransferase (ChAT) activity also reaches adult levels earlier in female septum, and at day 18 and in adults is greater in the female dentate gyrus compared to males. Hippocampal weight relative to body weight is consistently greater in females at all ages, particularly in Ammon's horn/subiculum. Such regional sex differences during development and in adulthood suggests that cholinergic enzyme activity is regulated locally in the hippocampal target tissue.

Acetylcholinesterase↗
PubMed1984

Development of the oviduct in quail during sexual maturation in relation to plasma concentrations of oestradiol and progesterone.

The macromolecular content (DNA, soluble proteins and ovalbumin) of the magnum and the plasma concentrations of oestradiol and progesterone were studied during sexual development of the Japanese quail. Rapid growth and differentiation of the magnum began between 21 and 28 days of age and rapidly reached the laying stage in about 20 days. This rapid change in magnum size occurred in a stepwise manner: cellular proliferation was observed first, followed by the synthesis and accumulation of specific proteins. Just before and during magnum growth, plasma oestradiol and progesterone concentrations followed different patterns: the initiation of epithelial cell proliferation was preceded by a sharp decrease in plasma progesterone. Maximum cell division occurred while plasma progesterone levels continued to decrease slightly; at the same time, oestradiol increased from 0.098 to 0.453 nmol/l. The decrease and finally the cessation of cell proliferation and the concomitant increase in ovalbumin concentration were related to almost constant levels of plasma oestradiol and increasing levels of plasma progesterone. Further development of the magnum (above 2.3 g weight) involving only the accumulation of secretory products was associated with an increased value of plasma progesterone. These data are consistent with the hypothesis that there are multiple hormonal signals controlling cell proliferation and synthesis of egg-white proteins in the oviduct. Progesterone may be one of the key signals that regulates the initiation of oviduct growth in the quail.

Animals↗
PubMed2004

Functional analysis of Plasmodium falciparum parasitophorous vacuole membrane protein (Pfs16) during gametocytogenesis and gametogenesis by targeted gene disruption.

Gametocytogenesis is a tightly regulated process marked by differentiation through distinct morphological forms and coordinated expression of sexual stage gene products. The earliest known gene product expressed at the onset of Plasmodium falciparum gametocytogenesis is Pfs16 localized on the parasitophorous vacuole membrane (PVM). Targeted gene disruption was undertaken to disrupt expression of Pfs16 and examine its potential role during sexual development. Three independent clones were demonstrated to have the coding sequence of Ps16 gene disrupted by the targeting plasmid by homologous recombination. No full-length transcripts and PVM localized 16 kDa protein were detected. Instead, all three "16ko" clones expressed a protein of 14 kDa recognized by Pfs16 specific antibodies that was mislocalized to an unidentified double membrane compartment in the parasites. Disruption of Pfs16 gene resulted in a significant reduction in gametocyte production, although the small number of gametocytes produced appeared to be normal by molecular and phenotypic evidences. Preliminary observation also suggested impaired ability of male gametocytes to exflagellate in vitro. Pfs16 does not appear to be essential for sexual development, instead may be required for optimal production of sexual parasites. Understanding mechanisms involved in the development of sexual stages of P. falciparum may identify novel targets for drugs and vaccines effective in reducing malaria transmission.

Animals↗
PubMed1992

Southwestern Internal Medical Conference: New developments in the diagnosis and treatment of sexual precocity.

This article covers considerations in the etiology of various forms of precocious puberty and premature sexual development. The normal pubertal process with maturation of the hypothalamic pituitary gonadal axis is reviewed. The differential diagnosis of precocious puberty is discussed with particular emphasis on the difference between gonadotropin-dependent and gonadotropin-independent processes. Established therapies and newer medical treatments with their pathophysiologic rationale are considered in detail.

Female↗
PubMed1999

Gonadal dysgenesis and Rokitansky syndrome. A case report.

BACKGROUND: Primary amenorrhea and lack of sexual development occur in gonadal dysgenesis due to missing ovaries. Primary amenorrhea with sexual development occurs in Rokitansky syndrome due to absence of the uterus, with normal ovarian function. The association of these two conditions has been previously described as a rare event. CASE: A 19-year-old woman presented with primary amenorrhea and lack of secondary sexual characteristics. Physical examination confirmed the absence of mammary development and of pubic and axillary hair. Pelvic ultrasound disclosed absence of the uterus and ovaries. Gonadotropin serum levels were in the menopausal range, and the karyotype showed two mosaic cell lines, 45,X/46,Xdic(X). Scanning of a large number of cells by interphase fluorescence in situ hybridization showed 12% of cells with a dicentric X chromosome. Laparoscopic study confirmed the absence of the uterus and ovaries, with normal fallopian tubes. CONCLUSION: This patient had two anomalies affecting reproductive performance, gonadal dysgenesis and congenital absence of the uterus, the first associated with an abnormal karyotype; the second seems to have occurred coincidentally. At this time there is no treatment for the reproductive dysfunction.

Adult↗
PubMed1991

Sexual stage development of cryptosporidia in the Caco-2 cell line.

We used the spontaneously differentiated human intestinal epithelial cell line Caco-2 to develop an in vitro model of Cryptosporidium sp. infection. The mean cell infection rate was 3% +/- 2%. Asexual stages of cryptosporidia were observed on day 2 postinoculation. Transmission electron microscopy showed the presence of macrogametes at day 5. This cell line appears to be suited to the study of the mechanisms by which biological agents inhibit both sexual and asexual development of cryptosporidia.

Animals↗
PubMedDate not supplied

[Hormones and development of sexual behaviour in the domestic sheep (author's transl)].

All motor patterns of male sexual behaviour can be observed in young lambs from the first days of the life. They considerably increase on weeks 2 to 5 when they decrease dramatically and remain stable up to over 6 months of age. This evolution has no direct relation with that of the physiological events. The adult female has a complete bisexual potentiality. The development of the sexual behaviour during ontogeny appears as a continuous process rather than to be limited to the period of puberty or sexual differentiation.

Animals↗
PubMed1992

The effects of serotonin manipulation during the postnatal period on the development of sexually dimorphic and non-dimorphic lumbosacral motor neuron groups in the albino Swiss rat.

Serotonin (5-HT) may act during development as a neurotrophic agent. Evidence suggests that sexually dimorphic regions of the mammalian nervous system (which often possess sexually dimorphic patterns of 5-HT innervation) could provide a model for this aspect of 5-HT action. Albino Swiss rat pups were treated with p-chlorophenyl alanine (pCPA, 200 mg/kg) or 5-hydroxytryptophan (5-HTP, 75 mg/kg) for 14 days after birth. As adults, the number of motor neurons in the sexually dimorphic spinal nucleus of bulbocavernosus (SNB) and dorsolateral nucleus (DLN), together with the non-dimorphic ventromedial nucleus (VM) were analysed. Postnatal treatment with 5-HTP had a general effect of increasing motor neuron numbers in all three groups. However, pCPA treatment had a marked and specific effect on SNB neuron numbers, increasing these in both sexes (+250% in females and +60% in males) compared with control animals. The results suggest that the postnatal innervation of ventral horn motor neurons by 5-HT-containing terminals may affect cell death at this time.

Animals↗
PubMed1995

Cognitions of gay and bisexual men in sexual situations: development of the sex and AIDS Thought Scale (SATS).

To examine the domain of thoughts experienced by gay men prior to and during sexual activity, the Sex and AIDS Thought Scale (SATS) was developed using a sample of 203 gay men. Principal components analysis revealed four factors, each with high internal consistency, that were labeled Safety Consciousness, Risk Justification, Sexual Importance, and Interpersonal Consequences. Correlations between SATS subscales and past condom use were calculated separately for intercourse with partners who either recently tested HIV negative (lower-risk partner) or did not (higher-risk partner). Correlational analyses revealed that, for higher-risk partners, Risk Justification and Interpersonal Consequences were significantly correlated with condom use during insertive and receptive intercourse. As anticipated, correlational analyses involving lower-risk partners yielded generally lower and non-significant correlations, providing evidence that the failure to account for perceived partner serostatus may attenuate the observed correlations between psychosocial variables and AIDS-relevant condom use. Implications for AIDS research and treatment are discussed.

Adolescent↗
PubMed2005

Hormonal therapies for individuals with intersex conditions: protocol for use.

Hormonal therapy forms part of the treatment of every intersex condition. For some conditions, such as salt-wasting congenital adrenal hyperplasia, hormonal replacement therapy is life saving because hormones necessary for survival (cortisol and aldosterone) are replaced. In contrast, other hormones such as androgens or mineralocorticoids are secreted in excessive amounts in congenital adrenal hyperplasia due to an enzyme imbalance, and the role of hormonal therapy is to suppress the unwanted hormone excess by exerting negative feedback. For patients with one of the many causes of hypogonadism, sex hormone replacement therapy may be prescribed to stimulate sexual development: growth of a hypoplastic penis in a young boy, pubertal changes (male or female), psychosexual development, and adult sexual behavior. It has equally important and highly beneficial effects on bone mineral density. Hormonal therapy is also used to treat the unborn child. For the last 20 years, prenatal dexamethasone treatment administered to the pregnant woman has been used to prevent the development of ambiguous genitalia in females with 21-hydroxylase deficiency. Outcome studies show this treatment to be well tolerated and, in general, efficacious. Intersex conditions are, however, difficult to treat because they may intrinsically perturb complex aspects of the person's gender identity, gender-role behavior, sexual orientation, sexual functioning, and psychologic adjustment. Furthermore, decisions made about the sex of an infant by doctors and parents do not always turn out to be correct; the person may grow up feeling uncertain about his or her gender identity, or worse still, harbor a sense of outrage about their life and treatment experiences. Such a person will have definite views about hormonal therapy when the time comes and skillful counseling will be needed. A vigorous debate about ethical aspects of current medical practices relating to intersex conditions has been waged for the last 7 years between certain patient advocacy organizations and the medical profession, and is expected to continue for some time. The quality of the debate will be improved by evidence. The results of a number of long-term follow-up studies have been published, and more are expected. The published studies show mixed, but mainly encouraging, results.

Adrenal Hyperplasia, Congenital↗
PubMed2000

Childhood sexuality: a decade of study. Part II--dissemination and future directions.

OBJECTIVE: One goal in perpetration prevention has been to increase the awareness and competence of professionals and parents in understanding and responding to the sexual behavior of children in order to reduce the risk of children developing sexually abusive behavior. A decade of experience in disseminating information about children's sexual development and behavior is reviewed in this paper. METHOD: Curricula developed at the Kempe Children's Center, University of Colorado Health Science Center, were used to provide training to professionals and paraprofessional caregivers. The information has evolved into a variety of models for different purposes in different settings. RESULTS: Children engage in a wide range of sexual behaviors, some of which adults observe or are told about by other children. Adults can be trained to evaluate what is developmentally expected or problematic, and to respond consistently on the basis of objective definitions and universal goals, rather than relying on the personal beliefs and values of individuals. CONCLUSION: Because children's sexual behaviors may pose a risk to themselves or others, there is a legitimate need for adults to respond to what they see and hear in order to validate or correct sexual learning in childhood. Adults are often not well informed about childhood sexuality and are eager to access objective information to inform their decision making in the care of children.

Adult↗