Stress and cortisol responses in men: differences according to facial symmetry.

Stress response is associated with increased activity in the hypothalamic-pituitary-adrenocortical axis. Chronic stress-induced elevation in cortisol may alter its own negative regulation with multiple long-term consequences for physical and psychological health. One of the most reliable physical traits associated with mental, apparent physical health, and competitiveness is the degree of facial fluctuating asymmetry. However, to our knowledge there are no studies regarding the relationship between cortisol levels, facial symmetry and male competitiveness, and how cortisol changes after a stressful test depending on these traits. Here, a group of 100 college men were photographed to obtain their facial asymmetry levels. They then, answered the perceived stress scale and the intrasexual competition test and donated two saliva samples (pre-and post-test sample) to measure the change in their cortisol levels after a stressful test. We found that basal cortisol levels were positively correlated with both perceived stress and competitiveness, but not with facial fluctuating asymmetry. Cortisol levels increased in most symmetrical men after a short stressful test, but it decreased in most asymmetrical men. The results suggest differences in endocrine responses according to facial fluctuating asymmetry in men and how these responses could be related to the maintenance of social status.

The G60S Cx43 mutant enhances keratinocyte proliferation and differentiation.

Transient knock-down of the gap junction protein Cx43 by antisense and siRNA, or gap junction block with mimetic peptides, have been shown to enhance epidermal wound healing. However, patients with oculodentodigital dysplasia (ODDD) express mutant Cx43 that leads to a chronic reduction in gap junctional intercellular communication. To determine whether mutant Cx43 in keratinocytes would impact upon the wound healing process, we localized Cx43 in human and mouse skin tissue expressing mutant Cx43 and assessed the ability of primary keratinocytes derived from a mouse model of ODDD to proliferate, migrate and differentiate. In the epidermis from an ODDD patient and in the epidermis of mice expressing the G60S mutant or in keratinocytes obtained from mutant mice, Cx43 was frequently found within intracellular compartments and rarely localized to punctate sites of cell-cell apposition. Primary keratinocytes derived from G60S mutant mice proliferated faster but migrated similarly to keratinocytes derived from wild-type control mice. Keratinocytes derived from mutant mice expressed abundant Cx43 and higher levels of involucrin and loricrin under low calcium conditions. However, after calcium-induced differentiation, similar levels of Cx43, involucrin and loricrin were observed. Thus, we conclude that during wound healing, mutant Cx43 may enhance keratinocyte proliferation and promote early differentiation of keratinocytes.

Oculodentodigital dysplasia: new ocular findings and a novel connexin 43 mutation.

OBJECTIVES: To describe new ocular findings associated with oculodentodigital dysplasia (ODDD) and a novel mutation in the connexin 43 transmembrane domain. DESIGN: Oculodentodigital dysplasia is a rare autosomal dominant disease characterized by multiple systemic abnormalities, most commonly of the ocular, nasal, dental, and limb structures. Herein, we studied 2 patients with ODDD. We describe their clinical findings and 2 ocular abnormalities not previously emphasized or reported. RESULTS: Optic nerve and retinal dysplasia was observed in both patients, and ciliary body cysts were observed in 1 patient. Both patients carried isolated in-frame deletion and missense mutations of the GJA1 gene on chromosome 6. CONCLUSIONS: Optic nerve and retinal dysplasia had not been emphasized as ocular manifestations of ODDD. Ciliary body cysts have not previously been reported in association with ODDD. CLINICAL RELEVANCE: Our findings support the potential significance of connexin 43 in the retina, optic nerve, and ciliary body. Retinal and optic nerve dysplasia may be more common than previously appreciated and may be associated with reduced vision. In addition, the ciliary body cysts observed in 1 patient may be secondary to weakened cellular adhesions between ciliary body pigmented and nonpigmented epithelium associated with the in-frame deletion identified in the affected patient. The presence of these cysts may exacerbate glaucoma or complicate its management.

Testosterone, facial symmetry and cooperation in the prisoners' dilemma.

Recent research has analyzed how individual characteristics, like the exposure to different hormones and symmetry, affect decision-making and strategic behaviour. The present article investigates the effect of symmetry, of exposure to testosterone (T) in utero and during puberty and of current T on cooperation in a Prisoners' Dilemma Game (PDG). T is a hormone with well known effect on males' behaviour, and that promotes activities that seek to increase reproductive success. Fluctuating Asymmetry (FA) reflects the ability of the organism to maintain a stable development and it is usually employed as a variable reflecting genetic quality (low FA values are thought to signal higher genetic quality). Our results show that subjects with intermediate levels of second to fourth digit ratio (a proxy of exposure to T in utero) and with high FA cooperate more often in the PDG. We also observe that the latter effect is due to the fact that FA has an impact on subjects' expectations about the behaviour of their counterpart in the game. These results reinforce the described link between markers related to genetic quality and cooperative behaviour. This possible linkage of individual condition and pro-social behaviour in humans clearly merits further attention.