Transsexual subtypes: clinical and theoretical significance

The present study was designed to investigate whether transsexuals can be validly subdivided into subtypes on the basis of sexual orientation, and whether differences between subtypes of transsexuals are similar for male-to-female (MF) and female-to-male transsexuals (FMs). Within a large transsexual sample (n = 187), homosexual and nonhomosexual subjects were compared on a number of characteristics before the start of treatment. Differences within MF and FM groups were also investigated. Homosexual transsexuals were found to be younger when applying for sex reassignment, reported a stronger cross-gender identity in childhood, had a more convincing cross-gender appearance, and functioned psychologically better than nonhomosexual transsexuals. Moreover, a lower percentage of the homosexual transsexuals reported being (or having been) married and sexually aroused while cross-dressing. The pattern of findings was different for MFs and FMs. No differences between homosexuals and nonhomosexuals were found in height, weight, or body mass index. A distinction between subtypes of transsexuals on the basis of sexual orientation seems theoretically and clinically meaningful. The results support the notion that in the two groups different factors influence the decision to apply for sex reassignment. The more vulnerable nonhomosexual transsexuals may particularly benefit from additional professional guidance before and/or during treatment

Activating effects of cross-sex hormones on cognitive functioning: a study of short-term and long-term hormone effects in transsexuals

In an earlier study we demonstrated that 3 months of cross-sex hormone treatment clearly influenced cognitive functioning in transsexuals. The aims of the present study were to examine: (a) whether we could replicate these findings in a new group of transsexuals; (b) whether a similar pattern of change could be found for novel tasks, i.e. tasks, not used in the previous study, that measured closely related cognitive abilities; (c) whether the cognitive changes following cross-sex hormone treatment had stabilized after 3 months or continued to develop over a period of 1 year; and finally, (d) whether the effects were quickly reversible when the hormone treatment was temporarily stopped. Again a pronounced effect of androgen treatment was found on spatial ability in female-to-male transsexuals (FMs) over a period of one and a half years. As expected, untreated male-to-female transsexuals (MFs) had higher scores on visuo-spatial tasks than untreated FMs; after 3 months of cross-sex hormone treatment, the group difference had disappeared, while after about 10 months of hormone treatment, the sex difference was reversed. These effects did not disappear after termination of cross-sex hormone therapy for a period of 5 weeks, but continued to change slightly in the same direction. Earlier findings of an opposite effect of cross-sex hormones on verbal fluency (i.e. MFs improved and FMs deteriorated after 3 months of cross-sex hormone treatment) were not replicated in this study, nor did we find an hormonal influence on other cognitive functions. This study shows that testosterone had an enhancing, and not quickly reversible effect, on spatial ability performance, but no deteriorating effect on verbal fluency in adult women (FMs). In contrast, anti-androgen treatment in combination with estrogen therapy had no declining effect on spatial ability, nor an enhancing effect on verbal fluency in adult men (MFs)

Relationships between sex hormones assessed in amniotic fluid, and maternal and umbilical cord serum: What is the best source of information to investigate the effects of fetal hormonal exposure?

Levels of testosterone (T) (total and free), androstenedione (A4), dehydroepiandrosterone sulphate (DHEAS), sex hormone-binding globulin (SHBG), and estradiol (E2) were measured by radioimmunoassay (RIA) in 156 normal pregnancies (77 male and 79 female fetuses). Samples were obtained from amniotic fluid, 2nd and 3rd trimester maternal serum, and umbilical cord serum at birth. During the critical period of brain differentiation, at the beginning of the second trimester of pregnancy, sex differences in T and A4 were found in amniotic fluid and not in maternal serum. This finding adds to the fact that mostly low and nonsignificant correlations were found for the different androgenic hormones between levels assessed in amniotic fluid and maternal plasma at this particular and very sensitive period of fetal brain development. On the other hand, high correlations were found for the same hormones between the samples of maternal serum in the 2nd and the 3rd trimester. Our data show that, of all available sources, amniotic fluid seems to be the best candidate to investigate the effects of early fetal androgen exposure

Is there an effect of prenatal testosterone on aggression and other behavioral traits? A study comparing same-sex and opposite-sex twin girls

Men and women differ in temperament and personality traits, such as aggression and sensation seeking. The sex hormone testosterone could play a role in the origin of these differences, but it remains unclear how and when testosterone could have these effects. One way to investigate the prenatal exposure effect of testosterone is to compare opposite-sex (OS) and same-sex (SS) female twins. It has been suggested that OS twin girls are exposed prenatally to elevated testosterone levels and that this may result in some masculinization of their personality and behavior. We measured sexually dimorphic traits and circulating testosterone levels in 13-year-old OS (n = 74) and SS (n = 55) twins. Testosterone levels showed a clear circadian rhythm, with higher levels in the morning than in the afternoon. Testosterone was higher in boys than girls, but similar in OS and SS twin girls. Testosterone was not in any way systematically related to the different personality traits. However, a sex difference in aggression proneness was observed, and OS girls showed a more masculine pattern of aggression proneness than the SS girls. It is argued that it is unlikely that this difference is due to social factors, such as a gender-specific upbringing

Adolescent anorexia nervosa patients have a discrepancy between neurophysiological responses and self-reported emotional arousal to psychosocial stress

In both clinical practice and research, eating disorder patients are reported to have difficulties in identifying and describing their feelings. They are often described as being unaware of the linkage between their feelings and their behavior. The present study experimentally induced emotions in adolescent anorexia nervosa (AN) patients to examine both self-reported emotional arousal and neurophysiological responses. A group of 10 AN patients and a group of 22 healthy controls (HC) were compared with respect to changes in self-reported emotional arousal and neurophysiological responses, heart rate (HR) and HPA-axis response (cortisol in saliva) during a public speaking test inducing anxious stress. The AN group reported higher levels of anxiety, as a result of stress, but this was not reflected in their HR or cortisol response. By contrast, in the HC group higher levels of self-reported anxiety coincided with clear increases in HR and cortisol. The data indicate that AN patients, in contrast to healthy individuals, show a discordance between self-reported emotional and neurophysiological arousal during psychosocial stress

Observation of CP violation in the B0 meson system

We present an updated measurement of time-dependent CP-violating asymmetries in neutral B decays with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. This result uses an additional sample of Upsilon(4S) decays collected in 2001, bringing the data available to 32 million B-anti-B pairs. We select events in which one neutral B meson is fully reconstructed in a final state containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2beta, is derived from the decay time distributions in such events. The result sin2beta = 0.59 +/- 0.14 (stat) +/- 0.05 (syst) establishes CP violation in the B^0 meson system. We also determine |lambda| = 0.93 +/- 0.09 {stat} +/- 0.03 {syst}, consistent with no direct CP violation.Comment: 8 pages, 2 figures, submitted to Physical Review Letter