Otoacoustic emissions (OAEs) and auditory evoked potentials (AEPs) are different in several special populations of subjects. For females having opposite-sex co-twins (OSDZ females) and for homosexual and bisexual females, OAEs are masculinized. Certain AEP measures from homosexual and bisexual females also are masculinized. Certain AEP measures from homosexual males are hypermasculinized. These...

Mammalian viviparity (intrauterine development of the fetus) introduced a new dimension to brain development, with the fetal hypothalamus and fetal placenta developing at a time when the fetal placenta engages hypothalamic structures of the maternal generation. Such transgenerational interactions provide a basis for ensuring optimal maternalism in the next generation. This success has depended ...

Spotted hyenas (Crocuta crocuta Erxleben) present a unique syndrome of reversal in behavioral and anatomical distinction between the sexes: females are heavier and more aggressive than males and dominant over them. The female's external genitalia include a false scrotum and a fully erectile pseudopenis through which mating and birth take place. Results of studies of circulating testosterone lev...

Most species' sex chromosomes are derived from ancient autosomes and show few signatures of their origins. We studied the sex chromosomes of Drosophila miranda, where a neo-Y chromosome originated only approximately 1 million years ago. Whole-genome and transcriptome analysis reveals massive degeneration of the neo-Y, that male-beneficial genes on the neo-Y are more likely to undergo accelerate...

Virilization, including penile enlargement and growth of pubic hair and facial acne, developed in a 2-year-old boy over a period of months. This sexual development was induced by incidental and unintentional dermal exposure to a testosterone cream that was applied to his father's arm and back as a part of body building regimen. Except for penile size, the other signs of virilization diminished ...

A Turkish boy was referred at the age of 3 6/12 years for the evaluation of a premature moustache. No other signs of virilisation were present. The endocrine evaluation led to the diagnosis of nonclassic congenital adrenal hyperplasia. Genetic analysis revealed 2 rare mutations of the CYP21A2 gene, the gene encoding for the 21-hydroxylase enzyme: a recently reported R132C mutation in exon 3 and...

The free-running circadian period is approximately 30 min shorter in adult male than in adult female Octodon degus. The sex difference emerges after puberty, resulting from a shortened free-running circadian period in males. Castration before puberty prevents the emergence of the sex difference, but it is not a function of circulating gonadal hormones as such, because castration later in life d...

During the intrauterine period the fetal brain develops in the male direction through a direct action of testosterone on the developing nerve cells, or in the female direction through the absence of this hormone surge. In this way, our gender identity (the conviction of belonging to the male or female gender) and sexual orientation are programmed into our brain structures when we are still in t...

OBJECTIVES The current study was designed to test a neurohormonally based theory of sexual orientation and preferred partner characteristics in homosexual men. The theory holds that the brains of homosexual men are masculinized and feminized directing attraction to targets younger and more masculine than self, and the brains of homosexual adolescents are incompletely masculinized and feminized ...

Cachexia, and particularly the loss of metabolically active lean tissue, leads to increased morbidity and mortality in affected patients. An impairment of strength and functional status is usually associated with cachexia. A variety of anabolic and appetite-stimulating agents have been studied in patients with cachexia caused by various underlying diseases. Overall, these studies have demonstra...