[Evaluation of regional prevention programs in France: the case of suicide prevention]. / Evaluation des résultats des programmes régionaux de santé en France: le cas des PRS de prévention du suicide.

Since 1994, a new prevention policy has been introduced in France. Over that period, eleven regions have conducted suicide prevention programs. It is possible today to assess the effects of these programs in retrospect. We have compared mortality data of the experimental regions to those of the other regions. We observed a significant difference in favour of the regions with suicide prevention programs. Results are discussed in relation with the achieved program content.

[Indications for the Schmid-Meyer frontal-temporal flap for nasal reconstruction. Four clinical cases]. / Les indications du lambeau frontotemporal de Schmid-Meyer dans la reconstruction nasale. A propos de quatre cas cliniques.

The fronto-temporal flap described by Schmid and modified by Meyer is a tubular flap with an internal supraciliary pedicle which allows the transposition of the temporal skin with the addition of ear cartilage on the tip of the nose or the ala nasi. This meticulous reconstruction requires four stages which are workable under local anesthesia. Four clinical cases allow to specify the advantages and the drawbacks of this technique. They place this technique in the therapeutic possibilities between the composite grafts and various local and distant flaps.

Mitochondria are a major site for folate and thymidylate synthesis in plants.

The subcellular distributions of folate and folate-synthesizing enzymes were investigated in pea leaves. It was observed that the mitochondrial folate pool (approximately 400 micron) represented approximately 50% of the total pool. Furthermore, all the enzymes involved in tetrahydrofolate polyglutamate synthesis were present in the mitochondria. In marked contrast, we failed to detect any significant activity of these enzymes in chloroplasts, cytosol, and nuclei. The presence of the tetrahydrofolate synthesis pathway in mitochondria is apparently a general feature in plants since potato tuber mitochondria also contained a high folate concentration (approximately 200 micron) and all the enzymes required for tetrahydrofolate polyglutamate synthesis. The specific activities of tetrahydrofolate-synthesizing enzymes were rather low (1.5-15 nmol h-1 mg-1 matrix protein), except for dihydrofolate reductase (180-500 nmol h-1 mg-1 matrix protein). Dihydrofolate reductase was purified to homogeneity. The enzyme had a native molecular mass of approximately 140 kDa and was constituted of two identical 62-kDa subunits. Interestingly, this mitochondrial protein appeared to be a bifunctional enzyme, also supporting thymidylate synthesis. The cell distribution of thymidylate synthase was also investigated. No significant activity was observed in cell fractions other than mitochondria, indicating that plant cell mitochondria are also a major site for thymidylate synthesis.

Isolation of H-protein loaded with methylamine as a transient species in glycine decarboxylase reactions.

A three-step protocol was devised to purify H-protein, which can be readily released as a soluble protein from pea mitochondria. After the final step of purification (anion-exchange chromatography) the native enzyme was eluted as two distinct peaks at 250 and 350 mM-KCl if the lysis buffer contained glycine. Each from exhibited an identical Mr of 15000 on SDS/PAGE and they were not distinguishable by PAGE under non-denaturating conditions. Both forms catalysed the rapid fixation of [14C]bicarbonate to the carboxy group atom of glycine during the exchange reaction, whereas the reversible exchange of electrons between NADH and lipoamide bound to the H-protein in the presence of 5,5'-dithiobis-(2-nitrobenzoic acid) was seen only with the form eluted at 350 mM-KCl. During the early steps of H-protein isolation, when P- and H-protein react together in the presence of glycine, the methylamine intermediate bound to the lipoamide of the H-protein accumulates in the medium at the expense of oxidized H-protein. Under these conditions the methylamine intermediate, which is a rather stable structure, was easily separated from the oxidized H-protein on ion-exchange chromatography. The methylamine bound to the lipoamide of the H-protein prevented the reversible exchange of electrons between NADH and lipoamide. High concentrations of glycine were required for the loading of H-protein with methylamine catalysed by a large excess of P-protein.

Basal forebrain and mesopontine tegmental projections to the reticular thalamic nucleus: an axonal collateralization and immunohistochemical study in the rat.

Using a double fluorescence retrograde labeling procedure, the present study sought to determine the degree to which basal forebrain and mesopontine tegmental neurons have axons that innervate both the reticular thalamic nucleus and the cerebral cortex. Immunofluorescence for choline acetyltransferase, somatostatin, and the calcium-binding protein parvalbumin was also performed to elucidate the neurochemical identity of basal forebrain and mesopontine tegmental inputs to the reticular thalamic nucleus. A significant portion (10-15%) of neurons in the basal forebrain and mesopontine tegmentum that were retrogradely labeled from the reticular thalamic nucleus were also found to be retrogradely labeled from the cortex. Many of these neurons stained positively for choline acetyltransferase. Of the basal forebrain neurons retrogradely labeled from the reticular thalamic nucleus, approximately 20% were found to be immunoreactive to choline acetyltransferase, whereas none was stained for somatostatin. A larger portion (up to 50%) of the basal forebrain neurons that were retrogradely labeled from the reticular thalamic nucleus were parvalbumin-immunoreactive, and some of these were also retrogradely labeled from the cortex. These results suggest that a subpopulation of cholinergic and non-cholinergic neurons in the basal forebrain and the mesopontine tegmentum may influence simultaneously the activity of neurons in the reticular thalamic nucleus and the cerebral cortex.