Plasma testosterone in homosexual and heterosexual women.

The authors measured plasma testosterone levels in 21 homosexual women and 19 age-matched heterosexual women. Although values for the two groups overlapped considerably, testosterone concentrations averaged 38% higher in homosexual than in heterosexual subjects. A statistically significant inverse correlation between age and testosterone level was found for heterosexual but not for homosexual women.

Psychological development and blood levels of sex steroids in male identical twins of divergent sexual orientation.

Despite differences in psychological development and personality structure, blood levels of testosterone and estradiol were equivalent in two monozygotic male twins of divergent sexual orientation.

Significantly decreased apparently free testosterone levels in plasma of male homosexuals.

Total and free plasma testosterone (T) were determined in male homosexuals. While total T showed no significant difference to a heterosexual control group, apparently free T in plasma was significantly lower (p less than 0.001) in 35 male homosexuals (mean +/- SD = 10.7 +/- 3.3 ng/100 ml) than in 38 male heterosexuals of similar age (13.3 +/- 4.5 ng/100 ml).

Antibody against the hepatitis type B core antigen. A new tool for epidemiologic studies.

Four random samples representing populations at low (volunteer blood donors), intermediate, (VD clinic patients), high (family contacts of chronic antigen carriers) and very high (male homosexuals) risk of exposure to HBV were surveyed. Among HBsAg and anti-HBs negative individuals an average of 3.3% were found to be anti-HBc positive, and among those with anti-HBs, 19.4% were anti-HBc positive. Anti-HBc, with concurrent anti-HBs and without, was detected more frequently in the high risk samples than in the low risk. Individuals was a past history of acute viral hepatitis were more frequently anti-HBc positive than those without such a history, and anti-HBc positivity was frequently accompanied by serum transaminase elevation. Anti-HBc may persist for many years after an episode of acute hepatitis. In households of carriers, the highest frequency of anti-HBc was observed among spouses, which would argue for the possibility of sexual transmission. A significant excess of females with both types of antibody was observed in families of carriers. Anti-HBc determinations in conjunction with other HBV markers, provide a useful new tool for epidemiologic studies.

Further studies on sex hormones in male homosexuals.

Plasma estrone, dihydrotestosterone, luteinizing hormone (LH), and percentage-free testosterone levels were determined in 26 predominantly or exclusively homosexual males (20 to 33 years of age) and in an age-matched control group. Although the homosexual and control groups showed a broad overlapping for all hormonal factors measured, highly significant differences between the groups were found without exception. The medians of the homosexual group (control group) and the significance levels for the two-sample rank tests were as follows: estrone 3.07 (2.43) ng/100 ml, P less than .01; dihydrotestosterone 66.0 (49.2) ng/100 ml, P less than .01; percentage-free testosterone 10.7% (9.7%), P less than .02; LH 35.1 (24.9) ng/ml, P less than .001. These findings can in part be explained by the higher LH secretion in the homosexual subjects.

A neuroendocrine predisposition for homosexuality in men.

In male rats, androgen deficiency during a critical hypothalamic organizational period was shown to give rise to a predominantly female-differentiated brain, homosexual behavior, and demonstration of a positive estrogen feedback effect. A positive estrogen feedback effect was also induced in intact homosexual men in contrast to intact heterosexual and bisexual men. Thus in 21 homosexual men an intravenous injection of 20 mg Presomen (Premarin) produced a significant decrease of serum LH levels followed by an increase above initial LH values. In 20 heterosexual and in five bisexual men, by contrast, intravenous estrogen administration, while producing a significant decrease of the serum LH level, was not followed by an increase above the initial LH values. Using a radioimmunoassay, plasma testosterone levels and 24-hr urinary excretions of unconjugated testosterone of adult homosexual men were found to be in the normal range as observed in heterosexual men. This finding suggests that homosexual men possess a predominantly female-differentiated brain which may be activated to homosexual behavior by normal or approximately normal androgen levels in adulthood.