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PubMed1998

A follow-up study for estimating the effectiveness of a cross-gender hormone substitution therapy on transsexual patients.

This follow-up study was carried out to validate the effectiveness of cross-gender hormone therapy embedded in a multistep treatment concept for transsexual patients. This therapy described in detail by the authors elsewhere and presented briefly below provides cross-gender hormone substitution to obtain an assimilation of secondary sex characteristics to the desired sex as quickly as possible. Personal and social background data of 46 male-to-female (M-to-F) and 42 female-to-male (F-to-M) patients passing through different stages of the treatment concept were included. In the Endocrinological Outpatient Clinic of the Max-Planck-Institute/Munich the effectiveness of cross-gender hormone replacement therapy as well as frequency and distribution of side effects were examined by follow-up examination of endocrinological parameters. Cross-gender hormones were administered either parenterally or orally. Blood samples were collected routinely after 2 to 6 months depending on the duration of hormone substitution and complication rate. The incidence of hyperprolactinemia in estrogen-treated M-to-F transsexuals lies in the range of studies published before, whereas the number of patients developing galactorrhea is significantly lower in our patients. The incidence of thromboembolic events during the time of cross-gender hormone treatment in our patients is negligible. Changes in hematological parameters are observed under cross-gender hormone therapy. With the cross-gender hormone regimen performed by us it is possible to generate less side effects in the treatment of transsexual patients than described before.

Female↗
PubMedDate not supplied

The intersexual animal. Associated problems.

An intersex animal is one possessing the characteristics of both sexes. Intersex animals, also called pseudohermaphrodites or hermaphrodites, are classified on the basis of their gonads. Pseudohermaphrodites possess the gonads of one sex but the secondary sex characteristics and external genitalia of the opposite sex. Female pseudohermaphrodites have ovaries but phenotypically have a masculine appearance. Male pseudohermaphrodites possess testes while having mixed or female external genitalia. Less common than pseudohermaphrodism is true hermaphrodism, wherein both testicular and ovarian tissue is present in various combinations. A testis may be found on one side in combination with an ovary on the contralateral side, an ovatestis (both testicular and ovarian tissue found in a single gonad) only may be present, or an ovatestis may be paired with a testis or ovary. Problems associated with intersex animals are not unique to intersexes but can be found in animals with normal chromosomal karyotypes. This chapter will review briefly the etiology of intersexuality and it will discuss the diagnosis and management of those problems associated with the intersex animal.

Animals↗
PubMed1996

Effects of prepubertal gonadectomy on physical and behavioral development in cats.

OBJECTIVE: To determine the effect of prepubertal gonadectomy on physical and behavioral development in cats. DESIGN: Prospective controlled study of kittens randomly assigned to 3 treatment groups: group 1, neutered at 7 weeks of age; group 2, neutered at 7 months of age; and group 3, sexually intact controls. ANIMALS: 31 clinically normal male and female kittens. PROCEDURE: Age at distal radial physeal closure and mature radius length were determined radiographically. Six behavioral characteristics were recorded monthly. At 1 year of age, body weight was recorded and thickness of the falciform ligament was measured from a lateral abdominal radiographic view. Secondary sex characteristics were also examined at 1 year of age. RESULTS: There were no differences between group-1 and group-2 cats for any of the study variables. Sexually intact cats (group 3) weighted significantly less than group-2 cats and had less falciform fat and earlier distal radial physeal closure than cats of both neutered groups. Group-3 cats manifested greater intraspecies aggression, less affection, and greater development of secondary sex characteristics than neutered cats. CLINICAL IMPLICATIONS: Neutering cats at 7 weeks of age had similar effects on physical and behavioral development, compared with neutering at the more traditional age of 7 months. These data lend support to the concept of prepubertal gonadectomy, already performed by many animal shelters/humane organizations, as a method of enhancing the effectiveness of pet population control programs.

Age Factors↗
PubMedDate not supplied

[Comparative characteristics of the sex steroid content in the blood plasma of the big-mouthed buffalo, silver carp and channel catfish during reproduction].

A radioimmunoassay was to determine the content of estrogens, progestins and androgens in the blood plasma of female and male big-mouthed buffalo, silver carp and canal sheatfish before reproduction and in the first two species during reproduction as well. It was shown that sexual hormones of all 3 groups were present in the blood of males and females of the species under study, the androgen concentration being significantly higher than the estrogen and progestin content in species of both sexes. Sexual dimorphism in the estrogen and androgen content in the blood of the fishes before reproduction was revealed. An exception was a silver carp with the absence of sex differences in the androgen content. There were no significant differences in the initial progestin levels in the species of both sexes. Sex differences in the time-course of gonadal hormones during reproduction were revealed: an increase in the level of steroids of all 3 groups was observed during ovulation in females, that of androgens and progestins only in females of the studied species excluding silver carp. No increase in the concentration of androgens was observed in male silver carps during reproduction. In spite of the general regularities of the time-course of sexual steroids in the reproduction of the studied species of fish significant specific differences were noted in the absolute values of sexual hormone concentrations.

Androgens↗
PubMed1994

[Comparison of skeletal development between rural and urban school-age children].

Skeletal development and other related indicators were measured in 1680 children aged 7-18 in urban areas of Harbin and rural areas of Hailun County in 1990-1992, and comparisons were made. The results showed that the skeletal age of urban children aged 7-17 was higher than that of rural children in both sexes, and this difference was significant in the early puberty stage. The difference in mean values of cortical thickness of the metacarpals between urban and rural children showed similar tendency. Sesamoid ossification in urban children occurred one year earlier than that in rural children in both sexes. In primary school-age children, skeletal age was highly correlated with body height and weight. The development of secondary sex characteristics in both sexes and the age at menarche in girls in urban areas were earlier than those in rural areas, and the onset of puberty occurred one year earlier in urban than that in rural children.

Adolescent↗
PubMed1994

Treatment of gender dysphoria (transsexualism).

Gender dysphoria, or transsexualism, is a condition involving incongruity between an individual's anatomic sex and personal sense of gender identity. Only in the last 15 years have Standards of Care been established and a professional organization developed to bring definition and consistency to the field (Harry Benjamin International Gender Dysphoria Association). A typical course of treatment lasts several years and includes psychological/psychiatric evaluations, completion of the "real life" test, administration of hormone therapy to create desired secondary sex characteristics, and finally sex reassignment surgery. As the field has developed and health-care professionals and the public have become more aware, increasing numbers of individuals are coming forward to seek evaluation and treatment. Published follow-up studies documenting long-term outcome are needed now. Current intervention techniques have progressed beyond the "experimental" stage and can be regarded as accepted medical practice.

Combined Modality Therapy↗
PubMed1975

Reproductive capacity of the mentally retarded.

Ninety-seven mentally retarded females were studied to evaluate parameters of growth and development of secondary sex characteristics and the incidence of ovulation. These patients were selected on the basis of age and etiological classification. Patients were classified as Down's syndrome, brain damaged, or undifferentiated. The following parameters of growth and development were studied: anthropometric, bone age, and sexual maturation. Sexual maturation studies consisted of breast development, pubic hair, axillary hair, menarche, menstrual pattern, and ovulatory patterns. The following observations were made from this study: 1. Physical growth and secondary sexual development were retarded in all parameters. 2. The undifferentiated and brain damaged groups showed almost identical patterns of growth and development of secondary sexual characteristics. 3. The Down's syndrome group was the most retarded in physical growth and in secondary sexual development. 4. Skeletal age was a better guide than chronological age or height and body weight to the prediction of development of secondary sex characteristics and age at onset of menarche. 5. In 26 mentally retarded females who had achieved menarche the incidence of ovulation was approximately 60 percent.

Adolescent↗
PubMed2006

A prospective analysis of juvenile male sex offenders: characteristics and recidivism rates as adults.

This research assesses the recidivism rates of a sample of 300 registered male sex offenders who were juveniles at the time of their initial arrest for a sex offense. This sample is followed for 3 to 6 years after they reached adulthood; recidivism rates are assessed during their adulthood only. The typical juvenile is a 15-year-old Caucasian male who was arrested for sexual assault or indecency with a child. The majority of the victims are females with an average age of 8. Although only 13 are rearrested during the follow-up period for a sex offense, more than half of the sample is arrested at least once for a nonsexual offense. The results of a Cox regression indicate that victim age, offender age, and victim sex are significant predictors of recidivism during adulthood.

Adolescent↗
PubMed2000

Muscle-dependent and hormone-dependent differentiation of the vocal control premotor nucleus robustus archistriatalis and the motornucleus hypoglossus pars tracheosyringealis of the zebra finch.

Sex differences in the vertebrate brain (brain sex) are thought to develop owing to the tissue specific action of gonadal hormones similar to the development of secondary sex characteristics of the body. Small sex differences in body anatomy could, however, retrogradely control the sexual differentiation of the central nervous system. This possibility has so far been verified only for motorneuron pools, since the connectivity of sex-specific higher brain areas to the sexual dimorphic periphery is frequently not well known. Here, we tested whether somatic sex differences feed back on higher brain areas by bilateral denervation of the syringeal musculature of zebra finches before, during, and after onset of estrogen-sensitive sexual differentiation of forebrain vocal nuclei such as RA (nucleus robustus archistriatalis). In the zebra finch, the sound-producing musculature (the syrinx), the syrinx motornucleus hypoglossus pars tracheosyringealis (nXIIts), and the RA are much larger in males compared to females. Tract tracing studies revealed that the volume and neuron size distribution of the nXIIts was sexually dimorphic in intact but not in animals denervated as juveniles. In contrast, the volume of RA and size of RA neurons of denervated animals were highly sexually dimorphic. Furthermore, estrogen masculinized the RA of denervated females. Thus, sexual differentiation of the RA but not of the nXIIts appears independent of somatic sex differences. The syrinx muscles are, however, important for the soma size of those RA neurons that project to the nXIIts.

Animals↗
PubMed2002

Aromatase activity in the ovary and brain of the eastern mosquitofish (Gambusia holbrooki) exposed to paper mill effluent.

Studies have shown that female mosquitofish living downstream of a paper mill located on the Fenholloway River, Florida, have masculinized secondary sex characteristics, including altered anal fin development and reproductive behavior. Masculinization can be caused by exposure to androgens in the water or from an alteration in aromatase activity in the fish. We hypothesized that aromatase activity would be inhibited by a component(s) of the paper mill effluent. Aromatase inhibition could masculinize the hormonal profile and, subsequently, secondary sex characteristics of the exposed females. Therefore, we predicted that ovarian and brain aromatase activity would be lower in the female mosquitofish from the Fenholloway River compared with the reference site, the Econfina River. Adult females were collected and standard length, body mass, anal fin length, and segment number were measured. Ovarian and brain aromatase activity were determined using a tritiated water assay. Fenholloway females had masculinized anal fin development as indicated by an increase in the number of segments in the longest anal fin ray (p < 0.0001), yet the length of the ray did not differ between sites (p = 0.95). Fenholloway females exhibited higher ovarian (p = 0.0039) and brain (p = 0.0003) aromatase activity compared with reference site fish. These data do not support aromatase inhibition as the mechanism for masculinization, suggesting that the masculinization of the Fenholloway female mosquitofish is due to androgenic contaminants. Future studies should examine the relationship between aromatase enzyme activity and exposure to environmental androgens.

Animals↗
PubMed1997

Effects of androgens on male sexual behavior and secondary sex characters in the explosively breeding spadefoot toad, Scaphiopus couchii.

In male Scaphiopus couchii, plasma elevations in androgens are associated with the seasonal expression of sexual behavior. To test the hypothesis that androgens are necessary for the expression of one aspect of sexual behavior, amplexus, and for the development of secondary sex characteristics in male S. couchii, the effects of testosterone (T) and dihydrotestosterone (DHT) on clasping behavior and thumb pad growth were investigated. Forty toads were divided into five treatment groups as follows: (1) intact, with no hormonal or surgical treatment; (2) sham-castrated, with silastic implants of cholesterol; (3) sham-castrated, with implants of T and DHT; (4) castrated, with implants of cholesterol; and (5) castrated, with implants of T and DHT. Displays of sexual behavior (amplexus) for each individual were counted during a 3-hr observation period at 2, 4, and 7 weeks after the surgical procedure. For each observation trial, there was no significant difference in the amount of clasping among treatment groups: virtually all individuals from each group displayed vigorous clasping. No calling was noted at any time. Thumb pad darkness of each individual was assessed at the 4- and 7-week time intervals. At both time periods, the thumb pads of androgen-treated males were significantly darker than those of cholesterol-treated males, while intact males remained intermediate. Measurement of plasma steroid levels from the treatment groups indicated that androgens were basal in the castrate group and higher in the implant treatment. These results suggest that in S. couchii, although androgens are associated temporally with the onset of reproductive behavior, they are not necessary for its expression. The elevation in androgens during the reproductive period may be instead important in the development and maintanence of secondary sex characteristics and possibly other reproductive functions.

Androgens↗
PubMed2004

Androgenic and estrogenic effects of the synthetic androgen 17alpha-methyltestosterone on sexual development and reproductive performance in the fathead minnow (Pimephales promelas) determined using the gonadal recrudescence assay.

The effects of the androgen, 17alpha-methyltestosterone were assessed on sexual development and reproductive performance in the fathead minnow (Pimephales promelas) using a gonadal recrudescence assay. In this assay, mature male and female fathead minnow, previously kept under simulated winter conditions (15 degrees C; 8:16 h light:dark regime) were transferred to simulated summer conditions (25 degrees C water temperature; 16:8 h light:dark regime) to induce gonadal recrudescence. To assess sexual development fish were exposed to nominal concentrations of 0, 0.1, 1, 5 and 50 microg/L 17alpha-methyltestosterone. After 3 weeks of chemical exposure, effects on condition (condition factor, CF), plasma vitellogenin (VTG), secondary sex characteristics, gonad growth (gonadosomatic index; GSI) and gonad histology were investigated. Reproductive performance, including reproductive output (egg production), spawning behaviour, and fertilisation rate were measured over a subsequent 3-week-period in breeding adults maintained in clean water. 17alpha-Methyltestosterone had no effects on the condition of fish at any of the doses tested. 17alpha-Methyltestosterone induced both androgenic and estrogenic effects with females generally more affected by 17alpha-methyltestosterone than males: atretic follicles and male-specific sex characteristics (androgenic effect) were induced in females at > or = 0.1 and > or = 1 microg/L 17alpha-methyltestosterone, respectively. An inhibitory effect on ovary growth occurred at an exposure concentration of 50 microg/L 17alpha-methyltestosterone. In males 1 microg/L 17alpha-methyltestosterone induced a concentration-response induction of plasma vitellogenin (estrogenic effect) likely due to its conversion into 17alpha-methylestradiol, rather to the competition with endogenous steroids and their cross reactivity with the estrogen receptor. In the fish breeding studies, concentration-dependent reductions in egg number, fertilisation rate and increases in abnormal sexual behaviour in females were observed. All of these effects occurred at exposure concentrations of > or = 5 microg/L 17alpha-methyltestosterone. Thus, it could be assumed that the observed estrogenic effects in male fathead minnow were likely to the conversion of 17alpha-methyltestosterone into the estrogen 17alpha-methylestradiol, rather to the acting of 17alpha-methyltestosterone itself. In conclusion to this, showing hormonally activity of 17alpha-methyltestosterone in fish down to 100 ng/L, indicates that its potency was close to the range of several naturally occurring estrogens.

Analysis of Variance↗
PubMed1989

Influence of age and testosterone levels on masculine development in rams.

Fifty wethers and 51 spring-born rams were divided into five groups and slaughtered at different seasons of the year at average ages of 271, 361, 459, 557 or 652 d to determine the age and season at which differences in secondary sex characteristics could be detected. Serum testosterone concentrations and testes weights were low in January when the rams were 271 d of age and again in April at 361 d of age. By July, at 459 d of age, testosterone concentrations and testes weights had peaked and then decreased the following November at 557 d and February at 652 d. In contrast with plasma testosterone concentrations and testes weights, buckiness scores, splenius to semimembranosus or semitendinosus muscle ratios, splenius muscle weights and neck and shoulder percentages were not seasonal. All of these measures increased significantly up to July and continued to increase slowly, but not significantly, thereafter. Muscle color and texture scores and rib eye color scores tended to increase in a linear manner for both rams and wethers as age increased. Subcutaneous fat from rams was yellower and softer than that from wethers over all age groups. Ram fat firmness did not change (P greater than .05) with age, and the only significant change in ram fat color was between the groups at 271 and 361 d of age. Overall, season of year coupled with higher levels of serum testosterone was related to initial development of secondary sex characteristics in ram lambs.

Adipose Tissue↗
PubMed2002

Evaluation of western fence lizards (Sceloporus occidentalis) and eastern fence lizards (Sceloporus undulatus) as laboratory reptile models for toxicological investigations.

A need is recognized for one or more laboratory reptile models for use in ecotoxicological studies and risk assessments. Maintenance of breeding populations of most reptile species under laboratory conditions is not practical because of their size and slow maturation rate. However, a number of species of spiny lizards (Sceloporus sp.) are small, mature quickly, and reproduce under laboratory conditions. We evaluated three populations of western fence lizards (S. occidentalis) and four populations of eastern fence lizards (S. undulatus) for their performance under laboratory conditions. We reared an F1 generation of each population and compared their performance relative to survival, growth, maturation rate, and reproductive output. A population from the San Joaquin Valley (CA. USA) performed especially well under laboratory conditions and is a good candidate for a laboratory model. We also examined the sensitivity of developing fence lizard embryos to an estrogenic chemical to determine if male secondary sex characteristics were affected. Microinjecting eggs with an estrogenic chemical (17alpha-ethinylestradiol) feminized males and prevented development of embryonic secondary sex characteristics. Therefore, embryonic fence lizards may be useful for studying the effects of endocrine-disrupting chemicals.

Animals↗