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Biomedical subjects

P Chevallier

Publications and source records attributed to P Chevallier.

At least 73 records · Page 4Linked to original sources
PubMed1998

Impact of hepatitis G virus co-infection on the course of hepatitis C virus infection before and after liver transplantation.

BACKGROUND/AIMS: Hepatitis G virus (HGV), a new RNA virus that is parenterally transmitted, has frequently been found in patients with chronic hepatitis C (HCV) infection but its role in chronic liver disease is unknown. The purpose of this study was to determine the prevalence of HGV infection in transplantation patients infected with hepatitis C and to assess the impact of HGV co-infection on the course of HCV infection after liver transplantation. METHODS: Eighty-nine liver transplantation recipients with persistent hepatitis C viremia detected by polymerase chain reaction (PCR) were evaluated. Serum samples were tested before and after liver transplantation for HGV RNA by two different PCR methods: LC assay (Abbott Laboratories) and an RT-PCR procedure which we developed using the silica gel technique for extraction of the HGV RNA. E2 antibodies were detected before orthotopic liver transplantation by an EIA-test. HCV RNA was quantified by branched DNA assay, and HCV genotype was determined. A mean of nine liver biopsy specimens were examined for each patient and the severity of the lesions was compared in HCV-positive patients with or without HGV co-infection. RESULTS: The concordance between the two HGV RNA detection methods was excellent and the reproducibility of our RT-PCR procedure was confirmed. The prevalence of pretransplantation and posttransplantation HGV infection was 11% and 19%, respectively. Pretransplantation HGV infection was positively correlated with posttransplantation HGV infection (p<0.001). Before transplantation the E2 antibodies seroprevalence was 34%. Seven patients became HGV RNA positive after transplantation, but all of them were negative for E2 antibodies. Among the patients who remained RNA negative after liver transplantation, 40% were positive for E2 antibodies (p=0.04). Pretransplantation clinical features (except AST mean value) were not different in patients with HCV and HGV co-infection and those with HCV only. After a mean follow-up of 34 months (range: 6 to 70), 67/89 (75%) patients developed histological features of recurrent hepatitis but the frequency of the occurrence of graft hepatitis was not different between HGV/HCV co-infected patients and those with HCV alone (p=0.89). The mean interval from orthotopic liver transplantation to recurrence was 12.2 months (range: 3-63), which was not different for HVG/HVC-co-infected patients and HCV-infected patients. The histological severity of posttransplantation liver disease, and the graft and patient survival were not different for patients with and without HGV co-infection. CONCLUSIONS: Our results suggest the general persistence of HGV infection after liver transplantation, but HGV co-infection did not appear to influence the posttransplantation course of HCV infection. Before transplantation the prevalence of E2 antibodies was 34%, and our data clearly indicate that E2 antibodies were protective against HGV infection.

Adult↗
PubMed1998

Clinical evaluation of the branched DNA assay for hepatitis B virus DNA detection in patients with chronic hepatitis B lacking hepatitis B e antigen and treated with interferon-alpha.

The aim of this study was to evaluate the Chiron branched DNA (bDNA) assay for detection of serum hepatitis B virus (HBV) DNA in patients with chronic hepatitis B lacking hepatitis B e antigen (HBeAg) and undergoing interferon (IFN) therapy. Results obtained with the bDNA assay were compared with those obtained using the Abbott liquid hybridization (LH) assay and the polymerase chain reaction (PCR). Serial samples (274) from 34 patients were analysed. Analysis of variance results indicated that bDNA values were more significantly correlated than LH values with both PCR positive/negative results (probability of artifact (Prob > F) = 0.7 and 0.09 for LH and bDNA assays, respectively) and presence/absence of precore mutations (Prob > F = 0.21 and 0.001 for LH and bDNA assays, respectively). Both bDNA and LH results correlated highly with alanine aminotransferase (ALT) values (both had Prob > F values of 0.0) while PCR was not correlated with ALT (Prob > F = 0.05). In 26 evaluable patients, a model based on a generalized Knodell score was used to predict response to IFN therapy, as defined by normalization of ALT values during therapy. This model discriminated well between non-responders and responders. The bDNA results correlated well with the generalized Knodell score, while the LH results did not (Prob > F = 0.04 and 0.19 for the bDNA and LH assays, respectively). In conclusion, the bDNA assay appears to be useful for quantification of HBV DNA levels in HBeAg-negative chronic hepatitis as it correlates with biochemical and histological indications of disease severity as well as with response to IFN therapy.

Analysis of Variance↗
PubMed1998

Right-sided sciatalgia complicating Crohn's disease.

Neurological complications of Crohn's disease due to involvement of the extradural space are extremely rare. A 40-yr-old woman with Crohn's disease affecting the terminal ileum presented with a right-sided sciatalgia. The patient did not complain of diarrhea or constipation. The serum fibrinogen and the C-reactive protein were elevated. Magnetic resonance imaging and computed tomography scan of the abdomen and pelvis demonstrated a mass in front of the sacrum up to but not including the first sacral vertebra. Surgical intervention, with resection of 15 cm of terminal ileum, led to the complete resolution of symptoms. In this case, the underlying cause of the neurological symptoms was most likely an infiltration of the right lumbosacral nerve caused by edema and inflammation of the terminal ileum in the vicinity of the presacral space. Unexplained lumbosacral neurological symptoms in a patient with Crohn's disease necessitate a magnetic resonance imaging or computed tomography scan to detect potential neurological compression.

Adult↗
PubMed1997

X-ray fluorescence used to characterize the salt content of proteins.

The quantitative measurement of the salt content in solid protein samples was performed using X-ray fluorescence. Linear calibration curves were obtained for chloride, calcium and sulfur using sulfur and chloride as internal standards in the range 1-10 protein molar equivalents. The detection limit was approximately 0.02 molar equivalents for chloride and less than 0.01 molar equivalents for calcium. X-ray fluorescence thus provides a non-destructive sensitive method of testing the efficiency of different purification methods. Commercial hen egg white lysozyme samples contain from 15 to 46 molar equivalents of chloride, whereas the calcium content remains less than 0.2 equivalents. Deionization on ion-exchange resins is a very efficient tool for removing ionic species since deionized lysozyme samples contain less than 0.34 molar equivalents of chloride. Extensive dialysis against water only partially removes chloride ions, the residual chloride content corresponding to the number of counter-ions necessary to ensure the electroneutrality of lysozyme when dissolved in water.

Journal Article↗
PubMed1997

[Venous endoprosthesis. Palliative treatment of superior caval syndrome of neoplastic origin].

Twenty-three patients with SVC syndrome were evaluated with CT and venography. The superior vena cava or its tributaries were either stenosed or thrombosed. The etiology was malignant in all cases: non small cell carcinoma (16 cases), mediastinal nodal metastasis (3 cases), lymphomas (2 cases), pleural mesothelioma (1 case), small cell carcinoma (1 case). The length of the stenosis ranged from 20 to 70 mm. The stents were placed via a femoral, jugular or brachial approach. Stenting was achieved in 22/23 patients (96%). Clinical symptoms subsided in 20/22 patients (87%). Mean follow-up was 15 weeks. Stents remained patent in 17/20 patients (78%). Stenting is a safe and effective treatment of SVC syndrome in patients with malignant conditions.

Adolescent↗
PubMed1997

Comparison of HCV RNA assays for the detection and quantification of hepatitis C virus RNA levels in serum of patients with chronic hepatitis C treated with interferon.

Detection and quantification of hepatitis C virus (HCV) RNA levels by using the standardized qualitative Amplicor HCV and quantitative Amplicor HCV Monitor assays (Roche Molecular Systems) were evaluated in 48 patients with chronic hepatitis C treated with interferon. Results were compared with an in-house reverse transcription and polymerase chain reaction (RT-PCR) assay and the branched DNA (bDNA) assay (Quantiplex, version 1.0, Chiron Diagnostics). Concordance of the qualitative results with the Amplicor HCV and in-house RT-PCR assays occurred in 82% of the samples. All but one of the discrepant specimens were found positive by the Amplicor HCV assay and negative by the in-house RT-PCR. Among the samples with HCV RNA levels measurable with the Amplicor HCV Monitor assay, 22% had HCV RNA titers below the detection limit of the Quantiplex assay. A statistically significant correlation was found between the 2 quantitative assays, although lower titers were obtained with the Amplicor HCV Monitor assay. More important, a good correlation was observed in the evolution of viremia as measured by the 2 assays during interferon therapy. During follow-up of interferon treatments, with the Amplicor HCV Monitor assay, persisting viremia was still detected in 27% of the patients who normalised alanine aminotransferase (ALT), emphasizing the bioclinical relevance of the assay. Pre-treatment serum HCV RNA levels above 10(5) copies/ml were found more frequently in nonresponders than in responders (76% vs. 44%; P < 0.05). Given their great sensitivity and the significant correlations, the Amplicor HCV qualitative and quantitative assays appear useful for the diagnosis and management of hepatitis C infection, and especially for monitoring of therapy.

Adult↗
PubMed1997

[Health and violence as perceived by young people, a study of the Parisian region].

We know better the violences made by the youngs than those they suffer from. The purpose of this study is to assess, as for a city surrounding Paris, the prevalence of the violences they felt and its relation with the psychic uneasiness. Some 344 youngs (from 15 to 25 years old) selected in the city, have filled in an autoquestionnaire. It has shown that 61.6% of them have already suffered from violences, among them 44.5% from adults and what is more from institutional adults. 13.7% of the selected youngs were victims of regular violences in school sphere and 12.8% in urban environment. The expression of a psychic uneasiness is linked to the previous violences they have felt. The feeling of call for help by a psychologist or a psychiatrist is in relation with the past psychic discomfort and not with the past suffered violences.

Adolescent↗
PubMed1996

Sonographic diagnosis of solitary solid liver nodules in cancer patients.

The purpose of this study was to analyse the sonographic patterns of solitary solid liver lesions in cancer patients and to evaluate the diagnostic accuracy of ultrasound alone and in combination with other techniques (liver function tests, histology). A total of 422 solitary solid liver lesions (SSLL) were diagnosed by ultrasound in cancer patients; 197 lesions were benign and 225 malignant. The predominant aetiology for hypoechoic SSLL (128 cases) was metastasis (112 cases), whereas most hyperechoic SSLL (265 cases) were haemangiomas (155 cases) rather than a metastasis (86 cases). The 29 isoechoic SSLL included 27 metastases and 2 benign lesions. A halo was found to be highly predictive of malignancy (97%-100%). The positive predictive value for malignancy of an SSLL was very high when the results of liver function tests were abnormal (97%-100%). In our experience, histological proof is unnecessary in the majority of liver lesions in cancer patients.

Alkaline Phosphatase↗
PubMed1996

Tolerability and utility of mangafodipir trisodium injection (MnDPDP) at the dose of 5 mumol/kg body weight in detecting focal liver tumors: results of a phase III trial using an infusion technique.

PURPOSE: To evaluate the tolerability of mangafodipir trisodium (MnDPDP) and its utility for enhancing the ability of magnetic resonance (MR) imaging to detect focal hepatic lesions compared with non-enhanced MR and contrast-enhanced computed tomography (CT). MATERIALS AND METHODS: 119 patients with focal hepatic lesions were examined by MR and by contrast-enhanced CT. MR was performed before and after the infusion of 5 mumol/kg MnDPDP, at a concentration of 10 mumol/ml. Histologic confirmation was obtained in 79 patients. RESULTS: There were no severe adverse events. Five patients reported mild adverse events related to the infusion. MnDPDP-enhanced SE T1 and GE T1 sequences revealed more focal lesions than the same sequences before contrast infusion in, respectively 22.6 and 36.1% of the cases, and fewer focal lesions in, respectively 5.9 and 1.7% of the cases. Contrast-enhanced MR demonstrated more focal lesions than the SE T2 sequence in 29.4% of cases and fewer lesions in 5.9% of cases. MnDPDP-enhanced MR revealed more nodules than CT in 31.1% of cases and fewer nodules in 13.4% of cases. The additional information provided by MnDPDP enhancement led to modification of management for 12 patients (10.1%). CONCLUSION: MnDPDP is a well-tolerated contrast agent allowing better MR detection of focal hepatic lesions than non-enhanced MR or contrast-enhanced CT.

Carcinoma, Hepatocellular↗
PubMed1995

Co-infection by hepatitis B virus and hepatitis C virus in renal transplantation: morbidity and mortality in 1098 patients.

The aim of the study was to analyse the influence of co-infection by hepatitis B virus (HBV) and hepatitis C virus (HCV) as compared with HCV infection alone in 1098 patients who received a kidney transplant between 1 January and 31 December 1991. At transplantation, the prevalence of anti-HCV antibodies was 21.40% (235/1098) while the prevalence of HBV infection was 9.85% (108/1096); 46 patients were co-infected with HBV and HCV, either 19.70% of HCV-infected patients and 42.60% of HBV-infected patients. Liver tests, galactose clearance and liver biopsy were compared in the 46 co-infected patients (HCV+HBV+) and in the 189 HCV-infected patients (HCV+HBV-). At the time of transplantation, cytolysis was present in 31.45% of HCV+HBV- patients (50/159) and in 40% of HCV+HBV- patients (16/40); cholestasis was present in 34.18% of HCV+HBV- patients (34/158) and 42.11% of HCV+HBV+ patients (16/38). At 6 months the incidence of biological abnormalities increased to 37% in HCV+HBV- patients (55/150) and to 52.5% in HCV+HBV+ patients (21/40), suggesting a more deleterious effect of the immunosuppressive therapy in the co-infected group. Over the course of transplantation, chronic hepatitis was present in 50% of HCV+HBV- patients and in 64.1% of HCV+HBV+ patients. Liver failure occurred in 7% of HCV+HBV- patients (12/156) and 17% of HCV+HBV+ patients (7/41). Galactose clearance was performed as a functional test in 68 patients: it was not significantly different in either group. Liver biopsy was performed in 108 patients at least once.(ABSTRACT TRUNCATED AT 250 WORDS)

France↗
PubMed1995

Prolactin and growth hormone mRNA and protein characterization in SMtTW rat pituitary tumours.

We have combined different techniques to analyse passages of five different rat spontaneous pituitary tumours (SMtTW) that were transplanted under the kidney capsule. These tumours were secreting prolactin (PRL), GH or both hormones. RIA, immunocytochemistry (ICC) and Western blot analysis were applied to characterize the hormone(s) stored (ICC and Western blot) and secreted (RIA). mRNA content was analysed by PCR, Northern blot analysis and in situ hybridization. The data point not only to the reliability of the techniques used at both protein and RNA levels for each tumour studied but also to the complementarity of some techniques. For example, whereas Northern blot analysis demonstrates the presence and size of hormone mRNA, in situ hybridization indicates the percentage of cells expressing a given hormone mRNA and allows the presence of one population (or more) of cells in a given tumour to be identified. Moreover, the tumours were compared with normal rat pituitary. Although the PRL and GH mRNAs were identical in size, the amount of mRNA was lower in the tumours. At the protein level, the PRL and GH variants exhibited a different pattern of expression in tumours compared with the normal rat pituitary. The biological significance of these differences is discussed.

Animals↗
PubMed1995

Normal protein and glycoprotein profiles of reflex tears and trace element composition of basal tears from heavy and slight deposits on soft contact lenses.

We investigated the hypothesis that lacrimal component accumulation on soft contact lenses (SCL) may be induced by an abnormal protein, glycoprotein, or trace element composition of the tear fluid. Individual tear samples were collected from healthy non-SCL wearers (normal patients) and SCL wearers grouped as either "slight-depositor" or "heavy-depositor" following SCL spoilage rate and frequency. The reflex tear proteins were analyzed by three electrophoretic procedures: sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) on minigels, isoelectric focusing (IEF) on immobilized pH gradients (IPG 4-7), and two-dimensional separation combining IEF in the first dimension to orthogonal SDS-PAGE. After separation, the proteins were detected by silver staining and identified by immunologic probes. The reflex tear glycoproteins were analyzed by lectin affinity associated electrotransfer of SDS-PAGE with a panel of five biotinylated lectin probes: Canavalia ensiformis (Con A), Artocarpus integrifolia (Jacalin), glycine max (SBA), Ulex europaeus (UEA 1), and Triticum vulgaris (WGA) agglutinins. The basal tear trace elements were analyzed by Synchrotron Radiation X-ray Fluorescence. Despite the highly sensitive techniques used in the study, the profiles of reflex tear proteins, glycoproteins, and trace elements appeared to vary slightly among individuals. No evident qualitative difference in reflex tear fluid related to SCL wear or deposit formation susceptibility was found. The presence or absence of a particular protein, glycoprotein, or trace element could not be correlated with a different reactivity to SCL. However, potassium and carbohydrate residues having affinity with Jacalin and WGA presented little but not significant variations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗