Preclinical and clinical evidence on the approach-avoidance conflict evaluation as an integrative tool for psychopathology.

The approach-avoidance conflict (AAC), i.e. the competing tendencies to undertake goal-directed actions or to withdraw from everyday life challenges, stands at the basis of humans' existence defining behavioural and personality domains. Gray's Reinforcement Sensitivity Theory posits that a stable bias toward approach or avoidance represents a psychopathological trait associated with excessive sensitivity to reward or punishment. Optogenetic studies in rodents and imaging studies in humans associated with cross-species AAC paradigms granted new emphasis to the hippocampus as a hub of behavioural inhibition. For instance, recent functional neuroimaging studies show that functional brain activity in the human hippocampus correlates with threat perception and seems to underlie passive avoidance. Therefore, our commentary aims to (i) discuss the inhibitory role of the hippocampus in approach-related behaviours and (ii) promote the integration of functional neuroimaging with cross-species AAC paradigms as a means of diagnostic, therapeutic, follow up and prognosis refinement in psychiatric populations.

Substantivity of sunscreens-preparation and evaluation of some quaternary ammonium benzophenone derivatives.

Synopsis In continuation of previous studies on keratin-substantive sunscreens, two series of quaternary ammonium compounds, derived from 2,4-dihydroxy and from 4-hydroxybenzophenone and containing O-alkyl and N-alkyl chains of different length were prepared and submitted to substantivity tests on wool, to microbiological tests on two bacterial and two fungal species, and to tests for allergenicity/irritation on human skin. All compounds were rapidly adsorbed by wool in aqueous solution: as expected, the maximum amounts adsorbed at equilibrium (S(max)), indicative of the skin substantivity, were greatest for the C12 N-alkyl derivatives, and showed a progressive decrease with increasing length of the N-alkyl substituent. No substantial substantivity differences were detected in four C12 quaternary derivatives, differing by the presence (or absence) of a 2-OH group in the benzophenone moiety and by the length of the O-alkyl (n= 2 or 3) side chain. When tested for antimicrobial activity, however, only the 4-hydroxybenzophenone C12 quaternary derivatives showed an order of activity comparable with that of two reference compounds. The conditions leading to a maximal antibacterial activity in the present compounds appeared to be the absence of the 2-OH group, and a shorter O-alkyl side chain. None of the new quaternary derivatives showed skin-irritant properties. The results of this investigation, while confirming the peak substantivity of C12 quaternary derivatives, indicate the possibility of dissociating, in a quaternary ammonium sunscreen, the skin substantivity from other unwanted side-effects, and offer some guidelines for the development of safer agents of this type.

[Estrogen therapy for the climateric and thromboembolic risk]. / Terapie estrogeniche per il climaterio e rischio tromboembolico.

PIP: Estrogens are very successful in premenopausal and postmenopausal therapy. Synthetic estrogens, such as ethinyl estradiol and mestranol, are used in hormonal contraception, while natural estrogen are used for treatment during and after climaterium. It seems that the major difference between the action of synthetic and of natural estrogens is at the level of the venous endotelial system. It has been proven that the use of synthetic estrogen used in hormonal contraception can increase the risk of thrombotic accidents, and that the risk is even greater in women over 40, or in smokers. Synthetic estrogens can alter lipid metabolism and blood coagulation, and often lead to hypertension. Such complications are not reported with the use of natural estrogens traditionally used in menopausal and postmenopausal therapy.^ieng