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Biomedical subjects

M Renoux

Publications and source records attributed to M Renoux.

198 records · Page 11Linked to original sources

Mitochondrial biochemical activities and heteroplasmy evolution in established D. subobscura cell line.

A mutant strain of drosophila (D. subobscura) has two types of mitochondrial genomes: a small population (20%) identical to that of the wild strain (15.9 kb) and a predominant population (80%) which has undergone a 5-kb deletion affecting more than 30% of the coding zone. Two cell lines were established from homogenates of embryos from mutant and wild strains. The activities of the respiratory complexes measured in the different cell lines are much lower than in the flies, indicating a glycolytic metabolism. Various modifications of the medium composition did not change this metabolic pathway. The mutant cell line has two types of populations of mitochondrial genomes and the heteroplasmy is equivalent to that measured in the mutant strain. However, the biochemical characteristics differ from those observed in the flies (i.e., the decrease of complex I and III activities), and the various systems of compensation for the consequences of the deletion that are showed in the mutant strain are no longer observed. Furthermore, in contrast with observations made on mutant flies, the heteroplasmy appears unstable in the mutant cell lines: after 60 or so generations, it progressively decreases until it disappears completely. The limited importance of mitochondrial energy metabolism in cells may explain the low impact of the mutation on the established cell line, in contrast to what is seen in the mutant strain.

Animals↗

[Acute leukemia and primary Vaquez' polycythemia. 20 cases].

The authors report the clinical and hematological course of 20 patients with polycythemia vera complicated by acute leukemia. This was responsible for 35,8% of the 53 deaths in the series of 103 patients treated with radioactive phosphorus. It occurred on average 12 years after the first treatment. The data in these cases are compared with those in the literature. The role of ionising radiation and/or the myelo-proliferative syndrome itself in the onset of acute leukemia is discussed.

Acute Disease↗

[Evans' syndrome during acute myelomonocytic leukemia. 2 cases].

The immune abnormalities observed during acute myeloblastic leukemia often remain undiagnosed for they generally have no practical consequences. The association of peripheral thrombopenia and a positive direct Coomb's test, during two cases of acute myelo-monocytic leukemia should be recognised owing to the difficulty of interpretation and the therapeutic consequences.

Anemia, Hemolytic, Autoimmune↗

[Multiple myeloma and acute leukemia. Simultaneous evolution of plasmacyte and myelomonocytic clones].

The authors report two cases of acute myelo-monocytic leukemia occuring during the course of multiple myeloma treated by local radiotherapy and melphalan. Both patients underwent a complete remission of their myeloma for 27 and 78 months. The myeloma relapsed suddenly in the form of an acute leukemia. In one case, the onset of acute leukemia was preceded by a syndrome of marrow failure with numerous crown-shaped sideroblasts and an excess of myeloblasts in the marrow. This stage lasted two years. The biochemical abnormalities of the red cells usually associated with refractory anemia and preleukemic conditions were present in the other case.

Aged↗

[Extramedullary lymphosarcoma, erythroblastopenia and gastric adenocarcinoma. Apropos of a case].

The authors report the case of a patient with lymphosarcoma and erythroblastopenia who died following a surgical operation for gastric carcinoma. The erythroblastopenia, corrected by radiotherapy of the lymphosarcoma, reappeared during the relapse. The link between these two diseases seems undoubted. The later appearance of a gastric carcinoma suggested the predisposing role of the first neoplasm, and/or its treatment, through an immunological disorder.

Abdominal Neoplasms↗

[Passive hemagglutination test for individual or epidemiologic diagnosis of human brucellosis].

Coupling of an extract from B. abortus strain 99 to sheep red blood cells by chromium chloride allowed to develop a highly specific and reliable passive hemagglutination test (H). Indeed, H was positive in 99.8 per cent sera from 968 known Brucella-infected heifers, while tube agglutination revealed only 59 per cent and complement fixation 90.9 per cent positive cases. H was positive in 153 sera from 778 proven or suspected human brucellosis where agglutination and/or complement fixation tests were positive, and in 21 sera negative to conventional tests. H demonstreated remote or undiagnosed human B. abortus infections in 28.6 per cent of 18 367 human sera randomly examined in a rural area. Therefore, a simple easy-to-perform passive hemagglutination test could replace a battery of conventional tests for the diagnosis of individual brucellosis, and epidemiologic surveys. The present study points to a high prevalence of undiagnosed brucellosis in man, specially in those area where cattle are raised.

Animals↗

[Proliferative myositis with compression of the sciatic nerve].

A case of proliferative myositis, an unusual inflammatory pseudotumour of skeletal muscle, is reported. This case was particular in that the lesion was located in the popliteal fossa, developed over a long period and above all, was revealed by compression of the sciatic nerve. The diagnosis was confirmed by peripheral biopsy of the mass which showed normal muscular tissue associated with numerous fibroblasts and with characteristic basophilic giant cells. The clinical, histological and pathogenetic features of the disease are discussed with emphasis on the importance of a thorough pathological examination to exclude with certainty a possible sarcoma.

Aged↗

[Mechanisms of action of levamisole, stimulating cellular immune responses].

Since LMS possesses a thiazole and an imidazole (IMZ) moiety, we compared in vivo activities of LMS and of IMZ on immune responses of mice, IMZ was unable to increase the number of direct or indirect plaque-forming spleen cells to sheep red blood cells (SRBC), the magnitude of delayed hypersensitivity to SRBC, and did not evoke the production of a serum factor which passively transferred the immune stimulation. LMS was repeatedly active in these three tests. In vivo activities of LMS appear to be linked to its sulphur moiety able to recruit and activate a new population of T cells, through serum mediators.

Animals↗

[Value of the self-evaluation of functional and painful disorders for the differentiation between fibromyalgia and inflammatory rheumatic diseases].

The authors sought to determine whether the self-report questionnaire developed by L.F. Callahan and T. Pincus is of use for the diagnosis of fibromyalgia when severe and/or chronic pain raises doubts as to an inflammatory rheumatic disease. This questionnaire evaluates the ratio between pain severity assessed on a visual analog scale and impairment of activities of daily living. High values suggest fibromyalgia, whereas low values occur in rheumatoid arthritis patients. The French translation of the questionnaire was completed by 15 fibromyalgia patients and 22 patients with inflammatory arthritic syndrome of whom 15 had rheumatoid arthritis. Mean pain/impairment ratio was 5.85 +/- 0.68 (SEM) in the fibromyalgia group versus 3.01 +/- 0.38 in the inflammatory rheumatism group. This difference was highly significant (p = 0.001 by Student's t test). The rheumatoid arthritis subgroup was also significantly different from the fibromyalgia group (p = 0.003). These findings are very similar to those reported by Callahan and Pincus. Our data confirm the value of this simple self-evaluation tool. In practice, ratios greater than 5 suggest fibromyalgia whereas ratios under 3 support the diagnosis of rheumatoid arthritis.

Activities of Daily Living↗

[Influence of levamisole on antibody production].

IgM and IgG anti-sheep red blood cells agglutinins were measured from dayy + 2 to day + 30 in SPF mice immunized with 108 SRC and treated with 2.5 or 25 mg LMS/dg. Untreated control mice produced high levels (1:8200) of IgM-antibodies from day + 4 to day + 20. Early, day + 4, IgG-agglutinins appeared together with IgM-antibodies in mice treated with 2.5 mg LMS/kg, whereas administration of 25 mg LMS/kg induced the synthesis of antibodies belonging only to the IgG class. Titres were significantly lower (1:512) in LMS-treated mice than in controls. The switch to IgG of antibody formation is another for the ability of LMS to stimulate T cell activities.

Animals↗