[Digital flow exploration by color Doppler ultrasound in patients with Raynaud's disease or systemic sclerosis]. / Exploration de la microcirculation pulpaire par écho-Doppler digital chez des patients présentant une maladie de Raynaud ou une sclérodermie.

BACKGROUND: Raynaud's phenomenon (RP) is a frequent vascular paroxysmal syndrome of the extremities. Generally benign, the condition is called Raynaud's disease (RD), which may reveal a connective tIssue disease, particularly systemic sclerosis (SS). We evaluated digital blood flow in patients with RD and SS using color Doppler ultrasound. PATIENTS AND METHODS: Ultrasound examination was performed with a newly developed multi-D linear array transducer (VFX 13-5 Siemens), which allows better resolution. We first measured the diameters of the digital arteries (appendix 1) then epidermal, dermal, and hypodermal thickness for each patient (appendix 3) and performed a qualitative and quantitative analysis of pulpar microcirculation (appendix 4 & 5). All measures were made at 25 degrees C, 45 degrees C, 11 degrees C and after recovery. Thirty-three patients were included: 14 with primary RD and 19 with SS as assessed by American College of Rheumatology criteria. RESULTS: The diameters of the digital arteries showed significant discrepancies allowed to distinguish primary RP from SS. At 11 degrees C, diameters were 0.6 +/- 0.2 mm for primary RP versus 0.2 +/- 0.3 mm for SS on lateral digital arteries (LDA) [p=0.005]; 0.7 +/- 0.2 mm for primary RP versus 0.4 +/- 0.3 mm for SS on medial digital arteries (MDA) [p=0.004]. After recovery, these diameters were respectively 1 +/- 0.2 mm versus 0.5 +/- 0.4 mm for LDA [p=0.000] and 1 +/- 0.2 mm versus 0.6 +/- 0.3 mm for MDA [p=0.000] (tables 1, 2, 3, 4). Similarly, pulpar vascularization was significantly higher in primary RP than in SS (tables 6, 7, 8). No difference was found in skin thickness nor in the epidermal aspect between the two groups (table 5). CONCLUSION: Color Doppler ultrasound shows morphological and dynamic differences between RD and SS.

Syntaxin 13 is a developmentally regulated SNARE involved in neurite outgrowth and endosomal trafficking.

In addition to its role in exocytosis, SNAP-25 is essential for axonal outgrowth. In order to identify SNARE proteins involved in neurite growth we have used SNAP-25 antibodies to affinity-purify protein complexes enriched in developing rat brain membrane extracts. We have identified a complex between SNAP-25 and syntaxin 13 predominantly present in brain at embryonic or early postnatal stages. We show that syntaxin 13 is developmentally regulated with a decrease in adult brain. In differentiated neuroendocrine PC12 cells as well as primary cortical neurons the protein is localized to a punctated and tubular staining in the perinuclear region and along processes with high levels in the central region of growth cones. Carboxy-terminally tagged syntaxin 13 was also detected on the plasma membrane by in vivo surface-labelling where it colocalized with SNAP-25. Syntaxin 13 has recently been shown to be implicated in early endosomal trafficking. In our study, colocalization with internalized transferrin in the cell body and along neurites confirmed endosomal location in both compartments. Finally, overexpression of full-length syntaxin 13 enhanced neurite outgrowth in NGF-stimulated PC12 cells, whilst it had no effect on regulated secretion. The data suggest that a syntaxin 13-dependent endocytic trafficking step plays a limiting role in membrane expansion during neuronal development.

Inhibition of the cAMP-dependent protein kinase by synthetic A-helix peptides.

The catalytic subunit of the cAMP-dependent protein kinase from Dictyostelium discoideum, PkaC, displays the same properties as its mammalian counterpart, except for being about twice as large in size. Sequence comparisons indicated the presence of a conserved alpha-helix (A-helix) within the N-terminal region of PkaC which could potentially establish close contacts with the catalytic core [Véron, M., et al. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 10618-10622]. We show in this report that a synthetic peptide with the A-helix sequence inhibits PKA activity, whereas unrelated peptides display no inhibitory activity. The inhibition seems competitive with respect to the kemptide substrate rather than due to binding to a secondary site. We further show by amino acid replacements that the last lysine of the A-helix sequence is involved in this specific inhibition. A model is proposed for the possible role of the A-helix.

[Results of 10 years of deafness screening and diagnosis in children and its implications. Early education of the young deaf child]. / Bilan de dix années de dépistage et diagnostic de la surdité de l'enfant et sa conséquence. L'éducation précoce du jeune enfant sourd.

In ten years, we have tested more than 1 200 children of 0 to 4 years in this way: at birth, within the maternity hospital, and then at 2, 6 and 9 months-old, doubtful cases with the Veit-Bizaguet audiometer and also Mrs Borel-Maisonny's sound toys: we have thus obtained the child's hearing test. Later on, according to age, we use R.O.C.--Peep-Show, tonal audiometry, and vocal audiometry with pictures. We also resort to objective means: systematically, tympanometry and Stape Reflex, and in difficult, doubtful cases, psychomotor retardation and autistic behaviour, we make B.E.R.A. We also search for hereditary, iatrogen and meningitic deafness. Such screening methods, at an early stage, to trace down severe and profound deafness enabled a demutization and early education of deaf children who will be equipped with stereophonic hearing aids; we use only an oral method with some cued speech. The children will thus be given a good school and social integration within the world of normal people. Then the children are in possession of a more structural language, of a voice of better quality and can develop all their abilities.