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Biomedical subjects

G Michel

Publications and source records attributed to G Michel.

At least 199 records · Page 11Linked to original sources
PubMed1995

[Helicobacter pylori and upper digestive disease at the Main Hospital of Dakar. Study apropos of 105 consecutive endoscopies].

Gastro-duodenal ulcer is a very frequent disease in Senegal and Helicobacter pylori (HP) being an ubiquitarian germ infects people living in developing countries in an over-early way and this most frequently. We have realized a prospective study dealing with 105 adult patients sent to hospital principal's endoscopy center. We were searching for HPs into three different methods which are as follows: using ordinary slats, clo-test, histological process. The results have confirmed the existence of a very high rate of infection due to HP, with among adults living in developing countries: 82% of our study. Likewise 95.8% of our ulcerous and erosive injuries at the bulb and 93.8% ulcerous and erosive gastric attacks were associated to HP infection. Those gastric and bulbar lesions were known to have followed a mild but chronic gastritis.

Adult↗
PubMed1994

[Ala4]surfactin, a novel isoform from Bacillus subtilis studied by mass and NMR spectroscopies.

When Bacillus subtilis S 499 was grown on a culture medium containing L-alanine as nitrogen source, a mixture of surfactins was obtained. Suitable chromatographic conditions allowed the separation of isoforms. Among these compounds, a new variant of surfactin was isolated and its structure was established by chemical and spectrometric methods, especially by NMR spectrometry. It contains a peptide sequence which differs from that of standard surfactin by the replacement of the L-valine residue by L-alanine residue in position 4. The folding mode of [Ala4]surfactin as deduced from NMR results was compared with that of standard surfactin and the structure/properties relationship issuing from the study of this new isoform is discussed.

Alanine↗
PubMed1994

The interleukin-8 receptor: a potential target for antipsoriatic therapy?

Interleukin-8 is assumed to play a central role in the pathogenesis of psoriasis. Since an increased expression of the interleukin-8 receptor has been observed both in polymorphonuclear leukocytes and in affected psoriatic epidermis, we were interested in whether the interleukin-8 receptor could be a molecular target of antipsoriatic compounds. Cyclosporine, calcitriol, calcipotriol or dithranol caused a dose-dependent decrease in interleukin-8 binding to cultured human keratinocytes, while interleukin-8 binding to granulocytes was not affected. In addition, the interleukin-8-induced human leukocyte antigen-DR (HLA-DR) expression of keratinocytes was nearly completely blocked by treatment of the cells with these substances. The inhibition of the keratinocyte interleukin-8 receptor and its function by antipsoriatic drugs may contribute to their therapeutic action.

Anthralin↗
PubMed1994

Polychlorinated biphenyls modulate protooncogene expression in Chang liver cells.

n Chang liver cells we studied the influence of polychlorinated biphenyls (PCB) on the expression of different protooncogenes. In cells incubated with medium supplemented with PCB we observed an early effect after 3 h on c-erbA and c-erbB RNA level. This reduction of RNA was due to a delayed transcriptional activation of the genes. The PCB congener 3,3',4,4',5-pentachlorobiphenyl (5-CB) in a 1,000-fold lower concentration influenced protooncogene expression in the same manner. In contrast c-raf RNA level increased transiently after 24 h. The fact that persistent chemicals like PCB interfere with protooncogene expression is particularly interesting in view of their tumor promoting activity.

Blotting, Northern↗
PubMed1994

Significance of IgG and IgM HCV antibody secretion in vitro in patients with chronic hepatitis C: correlation with disease activity and response to interferon-alpha.

Hepatitis C virus antibodies are found in the serum of most patients with chronic hepatitis C. However, the significance of the humoral response is still uncertain. In this study, in vitro IgG and IgM anti-hepatitis C virus secretion by peripheral blood mononuclear cells of patients with chronic hepatitis C was analyzed. Peripheral-blood mononuclear cells from 21 of 36 patients (58.3%) secreted IgG anti-hepatitis C virus in vitro, as demonstrated with anti-hepatitis C virus-specific enzyme immunoassays and recombinant immunoblot assays. Ten of the 36 patients (27.8%) showed both IgG and IgM anti-hepatitis C virus core in vitro. In 9 of these 10 patients, IgM anti-hepatitis C virus was also detected in serum. Patients with in vitro IgM or IgG anti-hepatitis C virus secretion had higher ALT levels in serum than did patients without such secretion in vitro (99.5 +/- 22.1 and 85.6 +/- 34.4 vs. 38.1 +/- 37.4 U/L; p < 0.0001, p < 0.001). Furthermore, with a histology activity score it was demonstrated that patients with in vitro IgM or IgG HCV antibodies (or both) had more severe chronic active hepatitis than did patients without in vitro hepatitis C virus antibody secretion (p < 0.01). To analyze the therapy outcome, we included in this study 18 patients who had received interferon-alpha previously. Seven of eight in vitro hepatitis C virus antibody-positive patients were nonresponders, whereas the in vitro hepatitis C virus antibody-negative patients were mostly complete therapy responders (8 of 10).(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine Transaminase↗
PubMed1994

Childhood anaplastic large cell lymphoma Ki-1/CD30: clinicopathologic features of 19 cases.

The authors report their cumulative experience of 19 children with what was previously called malignant histiocytosis (MH) but is now considered a true lymphoma and termed anaplastic large cell lymphoma (ALCL). The median age at diagnosis was 10 years and 6 months (range 2 y, 11 m, to 15 y). There were 13 males and 6 females. Most cases presented with fever, wasting and enlarged, often tender, lymph nodes. Other features were: fleeting cutaneous rashes in 7 cases; spontaneous regression of lymph nodes and skin lesions were seen in 5 patients. Bone marrow involvement was present in 3 cases, pulmonary infiltrate in 5, kidneys in 2, and central nervous system in none. The morphology of lymph node involvement was consistent with so-called MH, a description originally applied to sinusoïdal infiltration by large "histiocytic" cells. The coexpression of lymphoid activation antigens Ki-1/CD 30 (18/19), epithelial membrane antigen EMA (18/19) and interleukin-2 receptor/CD 25 (10/10) was the unifying immunopathologic feature of the neoplasm. Lineage antigens were not identifiable in 8/19 instances (null phenotype), while 10/19 expressed a T-cell phenotype. None of the tumors expressed histiocytic markers. After variable, but intensive, combination chemotherapy, 15 children out of 18 evaluable achieved complete remission (CR). Among all patients, thirteen are still alive in CR (ten in first CR) with a median follow-up of 5 years. This evaluation in the pediatric age group reinforces that so-called MH is a lymphoid neoplasm, a conceptual change that could lead to improved understanding and therapy.

Adolescent↗
PubMed1994

Measurement of liver microsomal cytochrome p450 (CYP2D6) activity using [O-methyl-14C]dextromethorphan.

The activity of human liver microsomal cytochrome P4502D6 (CYP2D6) is readily estimated by following the O-demethylation of [O-methyl-14C]dextromethorphan. The basis of the assay is the quantitative measurement of [14C]formaldehyde (0.05-4.0 microM) after addition of NaOH to the microsomal incubates and extraction with methylene chloride. The assay is relatively simple, sensitive (limit of detection is approximately 5.0 pmol HCHO/h/mg microsomal protein) and does not require the use of HPLC or an internal standard. Formation of radiolabeled formaldehyde in human liver microsomes is linear for 20 min, up to a final protein concentration of 1.0 mg/ml. Furthermore, the O-demethylase activity in a panel of microsomes prepared from a series of human livers was significantly correlated with the immunochemically determined levels of CYP2D6 protein (r = 0.925, p < 0.001), and was inhibited (> 89%) by quinidine and lobeline. In addition, [O-methyl-14C]-dextromethorphan O-demethylation was exclusively catalyzed by cDNA-expressed CYP2D6 in microsomes prepared from human B-lymphoblast cells. The method is suitable for rapid screening of compounds as potential CYP2D6 cosubstrates and/or inhibitors.

B-Lymphocytes↗
PubMed1994

A phase II study of high-dose cisplatin, vinblastine, bleomycin, and etoposide (PVeBV regimen) in malignant nondysgerminomatous germ-cell tumors of the ovary.

Fourteen patients with malignant nondysgerminomatous germ-cell tumors of the ovary were treated with a combination of high-dose cisplatin, vinblastine, bleomycin, and etoposide (PVeBV regimen). Nine patients received PVeBV as primary postoperative therapy, of whom four had no residual disease. Four patients received PVeBV for recurrent disease. One patient underwent PVeBV therapy as second-line treatment. Three patients with initial poor prognostic features were treated with early high-dose chemotherapy with autologous bone marrow rescue as consolidation therapy after two cycles of PVeBV. Ten of 14 patients (71%) are progression-free with a median follow-up of 6 year. Equal efficacy and less toxicity favor the combination of bleomycin, etoposide, and cisplatin (BEP) as standard treatment of ovarian germ-cell tumors in the 1990s.

Adolescent↗
PubMed1994

Action of neurohypophysial granule Lys-Arg endopeptidase on synthetic polypeptides comprising the processing sequence of provasopressin-neurophysin.

Neurohypophysial granule Ca(2+)-dependent endopeptidases have been allowed to act on synthetic polypeptides derived from the N-terminal sequence of bovine provasopressin-neurophysin, namely vasopressinyl-glycyl-lysyl-arginyl-alanylamide and vasopressinyl-glycyl-lysyl-arginyl-alanyl-methionyl-serinamide+ ++. Membrane-bound enzymes have been used at pH 5.5 for 16 hr at 37 degrees C. Products have been identified by high-pressure liquid chromatography (HPLC) and by mass spectrometry performed on substances isolated by HPLC. With both substrates, vasopressinyl-Gly-Lys-Arg(OH) has been identified as a product confirming the Lys-Arg specificity previously observed on small peptide fluorogenic substrates. Cleavage yields, however, appear low suggesting that some factors are missing, for example a targeting action of the precursor neurophysin domain to the granule membrane.

Amino Acid Sequence↗
PubMed1994

Anti-GOR in hepatitis D: specific association with hepatitis C virus superinfection.

A group of 113 patients with chronic hepatitis D was investigated for the presence of anti-GOR and liver kidney microsomal antibodies. Eight patients were anti-GOR positive and also positive for hepatitis C virus-infection. In sera from 16 patients liver-kidney microsomal antibodies were detectable by immunofluorescence. They were classified as LKM-3 due to their fluorescence pattern. Two of the LKM-3-positive sera were also anti-hepatitis C virus and anti-human immunodeficiency virus positive. None of these patients were positive for anti-GOR. Fourteen sera from LKM-3-positive patients reacted in Western blot with a microsomal protein at 55 kDa that differs from the 50-kDa LKM-1 (cytochrome P450IID6) antigen. Our studies demonstrate that hepatitis D virus itself does not induce an autoimmune reaction against the GOR antigen and that autoimmunity to the LKM-3 antigen induced by hepatitis D virus infection does not correlated with anti-GOR. These studies support the specificity of the anti-GOR response for hepatitis C virus infection.

Autoantibodies↗
PubMed1994

Different time courses of cardiac contractile proteins after acute myocardial infarction.

For the first time we have compared time courses of cardiac myosin light chain-1 (MLC-1), beta-type myosin heavy chain (MHC), troponin T (TnT), myoglobin, creatine kinase (CK) and CKMB in the same patients with acute myocardial infarction (AMI). Blood samples were serially collected in 23 patients with first-time AMI. All but 3 patients received intravenous thrombolytic treatment. TnT and MLC-1 time courses were biphasic in most patients and showed two distinct peaks in 13 and 8 patients, respectively. MHC time courses were usually monophasic. Only 1 patient showed a biphasic MHC time course with two distinct peak values. Although MHC and MLC were lower by about the fourth day after onset of AMI in early reperfused patients, reperfusion did not qualitatively alter MLC and MHC release (no significant influence on the first appearance in blood or on time to peak). MLC and MHC peaks correlated closely (r = 0.75, P = 0.0001), whereas TnT peaks were correlated less closely with MLC or MHC peaks (r = 0.58 each, P < 0.007). Peak values of all cardiac contractile proteins correlated closely and significantly with CKMB peaks (0.75 < or = r < or = 0.81, P < or = 0.0006). Myoglobin was the first marker to increase in blood after AMI and showed the earliest peaks, whereas MHC increased latest showing the latest peaks. TnT increased significantly (P = 0.0001) earlier than MLC and MHC. These results can be explained by the impact of the intracellular compartmentation of a cardiac protein on the rapidity with which it is released after AMI.

Adult↗
PubMed1994

In vitro secretion of anti-GOR protein and anti-hepatitis C virus antibodies in patients with chronic hepatitis C.

BACKGROUND/AIMS: Anti-GOR antibodies may reflect hepatitis C virus (HCV)--related autoimmunity or cross-reactivity with HCV core antigen. This study aimed to evaluate the clinical significance of anti-GOR antibodies. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from 35 patients with HCV and 48 controls and cultured for 8 days. The in vitro antibody secretion by PBMC was determined using specific enzyme-linked immunosorbent assays and recombinant immunoblot assay. RESULTS: In 22 of 35 patients with HCV (62.9%), PBMCs secreted anti-c22-3 or anti-c33c antibodies. However, in 3 of 48 controls (6.2%), PBMCs secreted anti-c33c antibodies alone. A significant in vitro anti-GOR response was found in 13 of 35 patients (37.1%) with HCV in relation to 4 of 48 controls (8.3%). In 12 of these patients (92.3%), anti-GOR were found in vitro and in serum. Two patients with HCV produced in vitro anti-GOR but not anti-c22-3 antibodies. Regarding disease activity, in vitro anti-GOR-positive patients with HCV had significantly higher alanine aminotransferase levels (108.8 +/- 17.8 U/L vs. 64.5 +/- 7.6 U/L; P < 0.01) and more frequent signs of chronic active hepatitis (10 of 13 [76.9%] vs. 10 of 22 [45.5%]) than patients with HCV without in vitro anti-GOR response. CONCLUSIONS: The humoral anti-GOR response in vitro is closely related to HCV infection and disease activity. Anti-GOR and anti-HCV core antibodies are regulated independently. It is likely that anti-GOR may reflect an HCV-associated autoimmune phenomenon.

Adult↗
PubMed1994

Microbial degradation of metal complexed cyanides and thiocyanate from mining wastewaters.

A microbiological examination of the soil from a cyanide wastewater storage basin was carried out. The storage basin contained water from the cyanidation process of gold extraction, and it was composed principally of simple cyanide, metal complexed cyanide, mainly cuprocyanide, ferro-ferricyanides and thiocyanate. Pseudomonas species were the principal bacteria identified in the soil. Using the storage basin soil as a seed sludge, its potential for the biodegradation of all the cyanide complexes in the mining wastewater was studied in the laboratory, using batch, fed-batch and continuous processes. The ammonia and sulphate produced were quantified. The presence of intermediate products was suspected. In the continuous process, total degradation of all cyanide was observed at a dilution rate of 0.066 day(-1).

Journal Article↗
PubMed1994

Long-term results of two VAB-like regimens (vinblastine + actinomycin-D + bleomycin + cyclophosphamide + cisplatin) in malignant germ cell tumours of the ovary.

21 patients with malignant germ cell tumours of the ovary were treated with two chemotherapy regimens including vinblastine, actinomycin-D, bleomycin, cyclophosphamide and cisplatin. Chemotherapy was delivered as primary postoperative therapy in 15 patients and for recurrent disease in 6 patients. 3 of 4 patients with pure dysgerminomas and 10 of 17 patients with non-dysgerminomatous tumours are alive without evidence of disease. The overall progression-free survival is 62% (95% confidence interval 45-77) with a median follow-up of 7 years. Two toxic deaths were observed. Less toxicity and better efficacy favour etoposide- and cisplatin-based regimens as standard chemotherapy for germ cell tumours of the ovary.

Adolescent↗
PubMed1994

A comparison of early effects with two dose rates in brachytherapy of cervix carcinoma in a prospective randomised trial.

This phase III randomised trial examined the early effects of two low dose rates (0.38 and 0.73 Gy/h) in brachytherapy of stage I and IIp cervical cancer patients. A total of 204 patients were included between January 1985 and September 1988. Since the main analysis of this paper concerned surgical difficulties, only the 155 patients (76%) on whom surgery was performed at the Institut Gustave-Roussy were retained in this analysis. Treatment consisted of uterovaginal 137Cs irradiation followed by immediate or deferred surgery. The two groups were similar for pretreatment characteristics except for endocervix involvement. Their brachytherapy parameters were also similar (60 Gy pear dimensions, doses to critical organs, total kerma, etc.). The factors with a poor prognosis were, for surgical difficulties, older age, stage II and a small irradiated pear volume; for difficulties with haemostasis, immediate surgery, stage II and previous surgery; and for difficulties in dissection, lymph node involvement. The dose rate significantly influenced surgical difficulties for the stage IIp patients operated on by deferred surgery. Those treated with the higher dose rate showed a 2-fold increase in surgical difficulties compared to those irradiated at the lower dose rate (P = 0.03). The independent prognostic factors for sterilisation of the surgical specimen were small tumour size and absence of lymph node involvement. An inverse dose rate effect was observed for medium size tumours, with significantly more sterilisations observed in stage IIp patients in the lower dose rate group (P < 0.01).

Adult↗