Biomedical subjects

M Raynaud

Publications and source records attributed to M Raynaud.

At least 37 records · Page 2Linked to original sources

PubMed1996

[MRI and Listeria monocytogenes rhombencephalitis].

Rhombencephalitidis is a serious form of brainstem inflammation, difficult to diagnose on the basis of clinical and laboratory findings alone. We describe the MR appearance of 3 cases of Listeria monocytogenes rhombencephalitidis and correlate the findings with clinical information. MR imaging is crucial for early diagnosis of this illness: patchy signal hyperintensity throughout the medulla and cerebellar peduncles on T2 weighted images, always in association with a hypointense dot; numerous gadolinium-enhanced microabcesses in the rhombencephalon. MR imaging is very useful for follow-up examinations.

Brain Abscess↗

PubMed1994

X-linked mental retardation exhibiting linkage to DXS255 and PGKP1: a new MRX family (MRX14) with localization in the pericentromeric region.

Gene localization was determined by linkage analysis in a large French family with X-linked mental retardation (MRX). Seven living affected males were clinically studied and the clinical picture was characterized by moderate to severe mental handicap with poor secondary speech acquisition. Seizures, slight microcephaly, simian crease, anteverted pinnae, and macroorchidism were observed in some patients only. Linkage analysis revealed no recombination between the MRX gene and two loci: DXS255 at Xp11.22 (Zmax = 3.31 at theta = 0.00) and PGKP1 at Xq11.2-q12 (Zmax = 3.08 at theta = 0.00). One recombination was observed between the gene and the two loci DXS164 at Xp21.2 and DXS441 at Xq13.3, respectively. These results suggested gene localization in the pericentromeric region of the X chromosome, and the LOD scores justified assignment of the symbol MRX14 to this family.

Adult↗

PubMed1993

[Left ventricular involvement in mucoviscidosis after 2 years of age].

BACKGROUND: The cardiac involvement in cystic fibrosis includes the rare cardiomyopathy seen in infants and changes in left ventricular performance in older children. POPULATION AND METHODS: 67 patients, 6 to 34 months-old (mean: 16.7), 37 male and 30 female, with cystic fibrosis, were studied. Their Shwachman score was < 70. None showed any clinical manifestations of left ventricular insufficiency, but 6 patients had right ventricular insufficiency. Echocardiography was performed on 58 patients; it showed dilation of the right ventricle in 32 of them. Left ventricular perfusion was studied with thallium 201 tomoscintigraphy and left ventricular ejection fraction with 99mTc ventriculography. RESULTS: The left ventricular ejection fraction was < 45% in 17 patients and scintigraphy showed hypofixation in 6 of them. In contrast, only 4 of the 50 patients with left ventricular ejection fraction > 45% had thallium hypofixation. CONCLUSIONS: Resting perfusion abnormalities are more frequent in patients with a low left ventricular ejection fraction. These perfusion abnormalities suggest that myocardial fibrosis complicates the advanced stages of cystic fibrosis.

Adult↗

PubMed1991

Diagnosis and categorization of small bowel neoplasms: role of computed tomography.

A retrospective study of 35 patients with small bowel neoplasms studied by computed tomography (CT) was performed. The tumor detection rate was 80%. Using the findings reported in the literature, an adequate histological diagnosis could be performed in 69% of the cases by CT. Lipomas, leiomyomas, leiomyosarcomas, and carcinoid tumors were well-recognized, but adenocarcinomas and lymphomas were often mistaken one for the other. An accurate preoperative staging was performed in 61% of the cases. CT failed to detect 75% of the invaded lymph nodes, 25% of the liver metastases, and 25% of the tumoral growth beyond the bowel wall. Despite major limitations in preoperative staging, a good detection rate and some features allowing a specific diagnosis advocate using CT along with the barium examination when clinical history suggests a small bowel tumor.

Adenocarcinoma↗

PubMed1986

Allogeneic responses of human fetal (22- to 25-week) peripheral blood lymphocytes: preferential recruitment of cytotoxic effector cells with both CTL activity and NK-like function.

In the present study, we have characterized human cytotoxic effector lymphocytes generated following in vitro immunization of normal fetal (22- to 25-week) peripheral blood mononuclear cells (FPBMC) by an allogeneic Epstein-Barr virus-transformed B-cell line termed LAZ388. Primary stimulations led to strong FPBMC proliferation. However, subsequent addition of LAZ388 cells to the cultures on Day 8 did not trigger conventional secondary responses. In fact, further proliferation of activated FPBMC required the addition of exogeneous interleukin 2. Cytotoxic activity generated in the mixed-lymphocyte reactions was assayed against LAZ388 immunizing cells as well as against the highly susceptible natural killer (NK) target cell line K562. Eight days after stimulation by LAZ388, there was no specific lysis and a moderate NK-like activity. However, following second and subsequent stimulations a strong killing was measured against both LAZ388 and K562 cells. Blocking experiments performed with relevant monoclonal antibodies suggested that cytotoxicity against immunizing cells was conventionally directed at MHC gene products. Effector cells were further studied using cloning procedures; it was found that all cloned cell lines able to kill LAZ388 cells were also strongly active against K562. Both types of cytotoxic function appeared to be mediated via surface receptors physically or at least functionally associated with T3 proteins.

B-Lymphocytes↗

PubMed1975

Delayed hypersensitivity to mono-azobenzene arsonate-N-acetyl-L-tyrosine. II. An operational model in the mouse.

Immunization of the mouse by free mono-ABA-Tyrosine (ABA-Tyr) in complete Freund's adjuvant leads to a specific sensitization. This can be assessed by increase in ear thickness after challenge with ABA-Protein conjugates. The intensity of the skin reaction is directly related to both the antigen dosage and the amount of BCG incorporated in the adjuvant. A close correlation has been shown between delayed skin reaction and "in vitro" lymphocyte proliferation in the presence of either ABA-Protein or free ABA-Tyr. In both "in vivo" and "in vitro" tests, sensitization is detectable from day 5 with a maximum on day 7. Contrasting with this strong cellular response, no antibody can be found. Thus, mouse sensitization with ABA-Tyr provides an operational model for pure cellular immunity. The extension of ABA-Tyr model to mouse may vacilitate the analysis of the involved cell populations.

Animals↗

PubMed1975

Delayed hypersensitivity to mono-azobenzene-arsonate-N-acetyl-L-tyrosine. I. Induction of cellular sensitivity in the rat.

In the guinea pig, mono-ABA-Tyrosone (ABA-Tyr) has been extensively studied as a hapten capable of inducing delayed type hypersensitivity in the absence of circulating antibodies. This model has been extented to the rat, and cellular sensitivity has been assessed both "in vivo" (skin reaction) and "in vitro" (cellular proliferation and lymphocyte migration inhibition). All the reactions studied follow a reproducible pattern with maximal positivity between 4 and 13 days, and negative responses after 20 days. Circulating antibodies were not detectable at any period after immunization. In view of the original properties of ABA-Tyr, and of the advantage of the rat as an experimental animal, the proposed model can be expected to facilitate further studies on the cellular mechanisms of delayed hypersensitivity.

Animals↗

PubMed1975

Some immunochemical and chemical aspects of S and R Shigella dysenteriae 1 endotoxins.

Endotoxins of S and R forms of Shigella dysenteriae 1 were prepared by NaCl-Na citrate extraction, purified by gel chromatography on Sephadex G 200 and on Sepharose 4B and subjected to immunochemical and chemical analysis. The toxins contained 25--30% of lipids, 40--50% of carbohydrates and 14--24% of protein. The lipid and protein moieties of the lipopolysaccharide-protein complexes exhibited no significant difference, whereas the sugar moieties differed markedly (both qualitatively and quantitatively), in relation to the growth form of the culture. The lipid moiety, which consists at least of 22 fatty acids, has the greatest relative content (approx. 50%) of behenic acid, 22:0, and palmitic acid, 16:0 (approx. 11%). In the protein moiety, at least 16 amino acids were determined; these amino acids were identical in both endotoxin types, but their total content was higher in the R form, giving an R:S ratio of 1.7 +/- 0.2. The sugar moiety consists of galactose, glucosamine and either rhamnose (in S endotoxin) or aldoheptose (in R endotoxin). The difference of the chemical composition of the sugar moiety is believed to account for the diametric difference in the immunochemical character, in particular the different behaviour in the electric field, of both endotoxin types. The average content of 3-deoxy-D-manno-2-octulosonic acid was determined as 0.5% for both S and R endotoxin. Trace amounts of O-phosphorylethanolamine were found. Individual aspects of the chemical and immunochemical analysis are discussed in detail.

Amino Acids↗

PubMed1974