[Defence mechanisms and coping strategies in men and women: a comparative and structural study based on the artistic production of people suffering from a break-up of their life project]. / Mécanismes de défense et stratégies d'ajustement au masculin et au féminin: etude structurale comparée basée sur la production artistique de personnes en rupture de projet de vie.

A comparative study of men and women suffering from a break-up of their life project allowed us examining the typically female and male manners to cope with trauma, anxiety, guilt, depression and internal destructivity. In a first stage, an exploratory study was focussed on 206 subjects, belonging to several clinical subgroups: people living in great precarity and long-term unemployed people, asylum seekers and refugees, drug addicts, prisoners and people coming out of prison. Secondly, arts therapeutic sessions were proposed with the aim of helping the participants finding an outlet to their situation. The artistic production (drawings and stories induced by music) was analysed with the help of original rating scales, constructed in a phenomenological and structural perspective. We will present a synthesis of our qualitative observations, as well as some results of typological and structural studies, computed with the help of non parametric statistical procedures on the data of N = 93 participants. The results allow us pointing to gender differences and defining typically male and female coping styles. Differential indications for psychotherapy can be extracted from these analyses.

Decreases in arterial pressure activate oxytocin neurons in conscious rats.

Hemorrhage and nonhypotensive hypovolemia are known to increase plasma levels of oxytocin (OT) and vasopressin (VP) in rats. The present experiments demonstrated that secretion of OT and VP also are stimulated by acute drug-induced hypotension. Injection of hydralazine abruptly decreased arterial blood pressure in conscious rats and induced Fos expression, a marker of neuronal activation, within OT and VP neurons in the hypothalamus. Hydralazine also elicited substantial increases in plasma levels of both OT and VP. Injection of chlorisondamine similarly elicited acute hypotension and increased plasma levels of OT and VP. Furthermore, when the hypotensive effect of chlorisondamine was blunted by coinfusion of phenylephrine, the induced increases in OT and VP were markedly attenuated. Across all treatments, arterial blood pressure was inversely related to plasma levels of OT and VP. Plasma osmolality was not increased by hydralazine, nor was there evidence of gastric malaise, two known stimuli for OT secretion in rats. These results suggest that arterial hypotension increases neurohypophysial release of OT and VP in conscious rats.

The role of ascorbic acid on the structural integrity of developing tooth germs.

Tooth germs grown in ascorbate deficient medium for up to 20 days underwent progressive and widespread changes. Proliferation and differentiation of preameloblasts and preodontoblasts progressed normally. Newly differentiated odontoblasts, however, became vacuolated when they began secreting: this suggested a metabolic disturbance. Failure to maintain differentiated odontoblasts, ameloblasts and pulpal cells resulted in aberrant dentin matrix, cessation of dentin production, and finally overall structural collapse with loss of normal morphology. Biochemical studies then were undertaken to define the lesion involved. The relative rate of collagen synthesis in ascorbate deficient cultures was comparable to that of ascorbate supplemented cultures, but the collagen was found to be underhydroxylated. In this state it would be unstable at 37 degrees and subject to preferential degradation. This correlates with the observation that a major fraction of the hydroxyproline in the scorbutic cultures was found in the medium as small molecular weight peptides. The overall effect of ascorbate deficiency was to deprive the tooth germ of the normal quality and quantity of collagen resulting in the characteristic histological and structural abnormalities observed. Flattening and deterioration due to structural failure most likely resulted from abnormal extracellular matrix synthesis in the supportive pulp and dentin due to the aberrant collagen.

The effects of ascorbic acid deficiency on collagen synthesis by mouse molar tooth germs in organ culture.

Second molar tooth germs from 2-day-old Swiss-Webster mice, grown in organ culture for 7 days in ascorbic-acid-deficient medium, synthesized about 65% as much protein (measured by incorporation of [14C]proline during a 24-h pulse) as did ascorbic-acid-supplemented controls. The newly synthesized proteins from ascorbic-acid-deficient cultures contained only about 7% of the hydroxyproline content of the controls. Collagenase digestion of the newly synthesized proteins showed that collagen comprised the same fraction of the total protein synthesized under both culture conditions. This result indicates that the ascorbate-deficient cultures made significant quantities of underhydroxylated collagen. Partial characterization of the collagen alpha chains on carboxymethyl cellulose columns showed an alpha1/alpha2 ratio of about 5, suggesting that at least two different species of collagen were synthesized. The alpha1/alpha2 ratio of the chains recovered from the ascorbate-deficient cultures was also about 5 but the chains were slightly underhydroxylated and the total amount of these chains which could be identified accounted for only a small fraction of the total collagen which was synthesized. A large fraction of the synthesized collagenous protein was found in the culture medium, mostly in the form of lower molecular weight peptides. It is concluded that most of the collagen which is synthesized by ascorbate-deficient tooth-bud cultures is not utilized by the component tissues, but is probably degraded and released into the medium.