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Samuel D. [Hepatic transplantation]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 2009; 33:42. [PMID: 19108969 DOI: 10.1016/j.gcb.2008.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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77
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Ichai P, Samuel D. [Liver transplantation for fulminant hepatitis]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 2008; 33:51-60. [PMID: 19111421 DOI: 10.1016/j.gcb.2008.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Zarski JP, Doffoel M, Filoche B, Marcellin P, Samuel D, Bedossa P. [Hepatitis C, cirrhosis and hepatocellular carcinoma]. ACTA ACUST UNITED AC 2008; 32:S117-20. [PMID: 18675181 DOI: 10.1016/s0399-8320(08)73274-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The screening for the detection of hepatocellular carcinoma is based on ultrasound sonography which should be realised in patients with post-hepatitis C cirrhosis with a delay between 3 and 6 months according to the most identified risk factors, in particular age and sex male. In the case of discovery of hypoechogen nodule < or = 1cm, a follow-up is mandatory because it is usually untypical by ultrasound sonography and to propose a liver biopsy in the case of an increasing in size is shown. The ultrasound guided cutting biopsy can precise the histological characteristics of the nodule, the grade, and indicate prognostic factors. The liver biopsy is also mandatory in the case of a nodule > 2 cm and when the ultrasound sonography is not contributive, especially when the nodule is between 1 and 2 cm in size.
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Adams D, Lozeron P, Antonini T, Kreib A, Azoulay D, Plante V, Ducot B, Castaing D, Samuel D, Said G. Efficacité à long terme de la Transplantation Hépatique sur la neuropathie et la survie des patients atteints de Neuropathie Amyloïde Familiale (NAF) liée à une variante Met30 de la Transthyrétine. Rev Neurol (Paris) 2008. [DOI: 10.1016/s0035-3787(08)70044-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
Hepatitis C virus (HCV)-related end-stage liver disease is the main indication for liver transplantation performed in Europe and the United States. Recurrence of hepatitis C in the graft is universal and may lead to chronic hepatitis in most patients and to cirrhosis in 20-30% of patients within 5-10 years of transplantation. The natural history of HCV recurrence is highly variable but leads to a lower survival rate than other recurrent liver diseases. The immunosuppressed status and several other factors have been linked with the pattern and severity of recurrence. What remains controversial are those factors associated with fibrosis progression and how these could be modified to improve outcome of recurrent hepatitis C. No single factor but a combination of several factors is associated with fibrosis progression on the graft. The major factors associated with accelerated disease recurrence include: high viral load pre- (>10(6) IU / mL) and / or early post-transplantation (>10(7) IU / mL at 4 months), donor older than 40-50 years, prolonged ischaemic time, cytomegalovirus coinfection, over immunosuppression and / or abrupt changes in immunosuppression, HIV coinfection, infection by genotype 1b. Cautious follow-up of the pathology of the graft is mandatory including routine biopsies and / or noninvasive monitoring of fibrosis.
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Price E, Shankar A, Samuel D, Millar M, Saha V, Hoffman P. Invasive Aspergillosis in a paediatric oncology unit – possible environmental factors. J Infect 2007. [DOI: 10.1016/j.jinf.2007.04.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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82
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Villamil F, Levy G, Grazi GL, Mies S, Samuel D, Sanjuan F, Rossi M, Lake J, Munn S, Mühlbacher F, Leonardi L, Cillo U. Long-term outcomes in liver transplant patients with hepatic C infection receiving tacrolimus or cyclosporine. Transplant Proc 2007; 38:2964-7. [PMID: 17112875 DOI: 10.1016/j.transproceed.2006.08.131] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Indexed: 11/15/2022]
Abstract
Choice of calcineurin inhibitor may be a contributing factor to deteriorating patient and graft survival following liver transplantation for hepatitis C virus (HCV). In our multicenter, open-label LIS2T study, de novo liver transplant patients stratified by HCV status were randomized to cyclosporine or tacrolimus. Follow-up data were obtained in an observational study of 95 patients. Mean follow-up was 34 and 37 months, respectively, for cyclosporine-treated (n = 47) and tacrolimus-treated (n = 48) patients. In patients not receiving antiviral therapy, 22 of 31 given cyclosporine (72%) and 24 of 29 given tacrolimus (83%) had biochemical recurrence of HCV. In 68 patients with at least one biopsy, histological evidence of HCV-related hepatitis was present in 27 of 31 (87%) cyclosporine-treated patients and 37 of 37 (100%) tacrolimus-treated patients (P = .02, chi-square test). Three-year actuarial risk of fibrosis stage 2 was 66% with cyclosporine and 90% with tacrolimus; for fibrosis stage 3 or 4 it was 46% and 80%, respectively. Three graft losses were attributed to HCV recurrence in cyclosporine-treated patients and six in tacrolimus-treated patients. Tacrolimus may be associated with increased risk of histological HCV disease recurrence compared to cyclosporine.
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Castaing D, Salloum C, Azoulay D, Adam R, Vibert E, Veilhan LA, Karam V, Saliba F, Ichaï P, Samuel D. Adult liver transplantation: the Paul Brousse experience. CLINICAL TRANSPLANTS 2007:145-154. [PMID: 18637466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
During the past 3 decades, more than 2,250 liver transplants were performed at Paul Brousse Hospital. Overall patient survival was 82% at one year, 71% at 5 years and 64% at 10 years. Our group has developed a variety of approaches to liver transplantation, including: 1. Anti HBs immunoglobulin prophylaxis for the prevention of HBV recurrence. Combination prophylaxis with lamivudine and anti HBs immunoglobulins reduced the rate of HBV re-infection to 20%. 2. Transplantation of HIV-HCV and HIV-HBV infected patients. These transplants are feasible and we achieved 2- year survival rates of 70% and 90%, respectively. The main problem was HCV recurrence which was more severe in HIV co-infected patients. 3. Transplantation for hepatocellular carcinoma on a cirrhotic liver with a single tumor <5 cm or <3 tumors <3 cm. 4. Transplantation for familial amyloidotic polyneuropathy (FAP). The 5- and 10-year survival rates were 76% and 72%, respectively. More than 100 livers obtained after hepatectomy from FAP patients were transplanted as "domino" living donor livers to patients with unresectable liver cancers with a 5-year survival rate of 64%. In some domino recipients, symptoms of FAP disease occurred more rapidly than expected and this could be an indication for a second transplantation of a non FAP-liver. 5. Split-liver transplantation for pediatric patients. This has increased the number of transplantable livers for children by 28%. 6. Split-liver transplantation for 2 adults. The grafts were prepared by ex-vivo or in-situ splitting and the overall 5-year survival rate was 56%. 7. Adult -to-adult living-related liver transplantation. There has been no mortality nor late complications in donors and the overall 5-year survival rate among recipients was 73%. 8. Liver retransplantation with good results in the elective situation. Retransplantation should be used with discretion in the emergency setting.
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Vijaylakshmi P, Muthukkaruppan VR, Rajasundari A, Korukluoglu G, Nigatu W, Samuel D, Brown DWG. Evaluation of a commercial rubella IgM assay for use on oral fluid samples for diagnosis and surveillance of congenital rubella syndrome and postnatal rubella. J Clin Virol 2006; 37:265-8. [PMID: 17049919 DOI: 10.1016/j.jcv.2006.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 07/25/2006] [Accepted: 09/15/2006] [Indexed: 11/30/2022]
Abstract
BACKGROUND Clinical diagnosis (surveillance) of rubella is unreliable and laboratory confirmation is essential. Detection of virus specific IgM in serum is the most commonly used method. However, the use of serum necessitates the drawing of blood, either through venipuncture or finger/heel prick, which can be difficult in young babies. Oral fluid samples have proved useful as an alternative, less invasive sample for virus specific IgM detection however until recently no commercial rubella IgM tests were available, restricting the usefulness of this approach. OBJECTIVES To evaluate the performance of the Microimmune Rubella IgM capture EIA using oral fluid samples from outbreaks as well as in cases of suspected congenital rubella syndrome (CRS). STUDY DESIGN Paired serum and oral fluids were collected from cases during a rubella outbreak in three provinces in Turkey. Matched serum and oral fluid samples were collected from children with suspected CRS in an active surveillance programme at the Aravind Eye Hospital in South India. Serum samples were collected as part of the measles surveillance programme in Ethiopia. RESULTS On serum samples the sensitivity and specificity of the Microimmune Rubella IgM capture EIA compared to Behring Enzygnost rubella IgM test was 96.9% (62/64; 95% CI 94.2-100%) and 100% (53/53; 95% CI 93.2-100%). On oral fluids compared to matched Behring results on serum the sensitivity was 95.5% (42/44; 95% CI 84.5-99.4%). The sensitivity and specificity of Microimmune Rubella IgM capture EIA on oral fluids from suspected CRS cases compared to serum results using Behring Enzygnost IgM assay was 100% (95% CI 84.5-100%) and 100% (95% CI 95.8-100.0%) respectively. CONCLUSION Microimmune Rubella IgM capture EIA has adequate performance for diagnosis and surveillance of rubella in outbreak using either serum or oral fluid specimens.
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Zvirbliene A, Kucinskaite I, Sezaite I, Samuel D, Sasnauskas K. Mapping of B cell epitopes in measles virus nucleocapsid protein. Arch Virol 2006; 152:25-39. [PMID: 16944047 DOI: 10.1007/s00705-006-0837-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Accepted: 07/11/2006] [Indexed: 10/24/2022]
Abstract
The B-cell response against measles nucleoprotein (MeN) plays an important role in the control of measles infection. However, the data on B cell epitopes of MeN are still limited. The objective of this study was to identify B cell epitopes in MeN using monoclonal and polyclonal antibodies raised against recombinant yeast-expressed MeN (rMeN) as well as human sera from measles-positive individuals. After immunization of mice, 15 monoclonal antibodies (mAbs) against rMeN were generated. The B cell epitopes were localized using recombinant overlapping MeN fragments, PepScan analysis, and competitive ELISA. The epitopes of 14 mAbs were mapped within the C-terminus of MeN between amino acids (aa) 419 and 525. Four mAbs recognized a linear epitope located within a sequence of aa 440-448. Competitive ELISA revealed a cluster of conformational mAb epitopes. Cross-inhibition studies with human sera demonstrated similar localization of B cell epitopes recognized by serum antibodies from naturally infected individuals. Thus, the majority of B cell epitopes are located at the C-terminal domain of MeN. These findings provide new data on the antigenic structure of MeN and are in agreement with recent experimental evidence indicating that the C-terminal domain of MeN is well accessible on the surface of nucleocapsid-like structures.
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Cohen BJ, Parry RP, Doblas D, Samuel D, Warrener L, Andrews N, Brown D. Measles immunity testing: Comparison of two measles IgG ELISAs with plaque reduction neutralisation assay. J Virol Methods 2006; 131:209-12. [PMID: 16188328 DOI: 10.1016/j.jviromet.2005.08.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 08/08/2005] [Accepted: 08/08/2005] [Indexed: 11/18/2022]
Abstract
Two commercial IgG ELISAs, one based on recombinant nucleocapsid antigen and one based on cell culture grown native virus antigens, were evaluated for measles immunity testing by comparison with plaque reduction neutralisation test (PRNT). Qualitative results of the two ELISAs showed 92% agreement with those of PRNT. The sensitivity of the two ELISAs was 89.6%. False negative ELISA results were obtained in 10% of sera, mainly sera containing low levels of neutralising antibody. The specificity of both ELISAs was 100%. Measles IgG ELISAs perform adequately for immunity testing, correctly identifying seronegative individuals for vaccination.
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Di Liberto G, Roque-Afonso A, Fallot G, Samuel D, Féray C. P.173 Clinical and therapeutic implications of HCV compartmentalization. J Clin Virol 2006. [DOI: 10.1016/s1386-6532(06)80353-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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88
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Antonini T, Costa Faria L, Roque-Afonso A, Sebagh M, Ichai P, Saliba F, Samuel D. P.125 Severe reactivation of hepatitis B virus: experience of a single centre. J Clin Virol 2006. [DOI: 10.1016/s1386-6532(06)80305-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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89
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Taillandier J, Alemanni M, Samuel D, Bismuth H, Lioté F. Rapid multifocal chondrolysis after liver transplantation in four patients. Ann Rheum Dis 2005; 65:118-20. [PMID: 16344497 PMCID: PMC1797985 DOI: 10.1136/ard.2004.034207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Favourable clinical outcomes achieved with liver transplantation may be jeopardised by corticosteroid-induced osteoarticular complications, such as osteoporosis or aseptic osteonecrosis. CASE REPORT A previously unreported joint complication in liver transplant recipients is described. METHODS Retrospective study of liver transplant recipients in whom destructive joint disease developed, identified among 330 symptomatic patients out of a total of 1260 managed over a 15 year period (November 1984-January 2000) in a university based liver transplantation centre. RESULTS In four patients (23-56 years), rapid chondrolysis developed 2-12 years after transplantation in more than three weightbearing or non-weightbearing joints free of radiological features of avascular osteonecrosis, evidence of infection, or defined inflammatory arthritis. Pathological examination of five hip joints and one knee joint found no evidence of infection or inflammation. Six joint replacement procedures were performed successfully in three patients. CONCLUSION Clinicians managing liver transplant recipients, and perhaps recipients of other organs, should be aware that rapid chondrolysis may develop. The pathogenesis of this rare complication is unclear.
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Samuel D. [Liver transplantation in patients co-infected with HIV]. Med Mal Infect 2004; 34 Spec No 2:9-11. [PMID: 15801532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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91
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Francès C, Marcellin AG, Agbalika F, Calvez V, Dussaix E, Bigorie A, Samuel D, Kreis H, Legendre C, Lebbé C. TRANSMISSION OF HUMAN HERPESVIRUS 8 THROUGH THE GRAFT. Transplantation 2004. [DOI: 10.1097/00007890-200407271-00185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Vittecoq D, Teicher E, Merad M, Vallée JD, Dussaix E, Samuel D. [Liver transplantation: is it possible in HIV/HCV co-infected patients?]. ACTA ACUST UNITED AC 2004; 51:525-7. [PMID: 14568603 DOI: 10.1016/s0369-8114(03)00172-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The prognosis of HIV infection has been modified by antiretroviral therapy. However, the morbidity and the mortality of HCV co-infection increase and may be a major problem of health service. Up to now co-infected patients are excluded of transplantation due to complexity, the ethical aspects, the immunodeficiency and the co-infection. This study tries to estimate the feasibility in this population. Between December 1999 and March 2002, seven patients were transplanted. The average of CD4 was 332/ml; the viral load was <50 copies/ml. Before transplantation, no patient had experienced opportunist infection and all patients received antiretroviral therapy adapted to their history. The average follow-up is of 14 months: one patient died 3 months after transplantation, the other one presented a candida in oesophagus, the average of CD4 was 280/ml, and viral load was <50 copies/ml in five patients. A relapse of HVC was observed in all patients. Interferon/rivabirine therapy was proposed for four patients. Every patient received tacrolimus and corticoids. HAART were modified four times for toxicity and one time for virological failure. We observed two cases of transient renal insufficiency, two cases of diabetes, two cases of pancreatitis, and abnormalities of the respiratory mitochondrial chain in four patients. Finally, liver transplantation in HIV-HCV co-infected patients seems to be feasible when strict criteria of selection are taken into account. This still experimental strategy requires a multidisciplinary partnership.
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Duclos-Vallée JC, Sebagh M, Rifai K, Johanet C, Ballot E, Guettier C, Karam V, Hurtova M, Feray C, Reynes M, Bismuth H, Samuel D. A 10 year follow up study of patients transplanted for autoimmune hepatitis: histological recurrence precedes clinical and biochemical recurrence. Gut 2003; 52:893-7. [PMID: 12740348 PMCID: PMC1773675 DOI: 10.1136/gut.52.6.893] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND AIM Autoimmune hepatitis (AIH) has been reported to recur after orthotopic liver transplantation (OLT) in 10-35% of patients in small series with a short follow up. The aim of the present study was to examine the clinical and histological outcome more than 10 years after OLT for AIH. PATIENTS AND METHODS Seventeen women with a mean age of 30 (12) years at the time of OLT, selected from among 44 patients transplanted for AIH, were followed for more than 10 years. The criteria for definite AIH, as established by the International Autoimmune Hepatitis Group, were met in every case. Liver biopsies were performed 1, 2, 5, and 10 years after OLT, and when indicated by abnormal liver function tests. Specimens were examined for evidence of recurrent AIH, namely interface hepatitis, lobular activity, portal lymphoplasmocytic infiltration, and fibrosis. Other signs of recurrence included hypertransaminasaemia, serum autoantibodies, and the response to steroid reintroduction or significant steroid dose increments. RESULTS AIH recurred in 7 (41%) of 17 patients. In four patients histological abnormalities were detected by means of protocol biopsies 1-5 years before the onset of biochemical abnormalities. Two patients developed severe recurrences after 10 and 15 years, respectively, and required treatment with steroids and tacrolimus. In the other three patients histological recurrence was detected 0.6-3 years post-OLT, concomitantly with biochemical abnormalities. CONCLUSIONS AIH recurred in 41% of patients followed for more than 10 years after OLT. As histological signs preceded biochemical abnormalities in four patients (23.5%), regular liver biopsy is warranted after OLT. Detection of isolated histological signs may call for closer follow up and/or a change in immunosuppressive therapy.
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Poynard T, Marcellin P, Bissery A, Myers RP, Moussalli J, Degos F, Dhumeaux D, Riachi G, Bronowicki JP, Brissot P, Buffet C, Serfaty L, Naveau S, Sogni P, Beaugrand M, Gayno S, Larrey D, Samuel D, Eugene C, Pol S, Bedossa P, Daurat V, Chaumet-Riffaud P. Reinforced interferon alpha-2b and ribavirin is more effective than standard combination therapy in the retreatment of chronic hepatitis C previously nonresponsive to interferon: a randomized trial. J Viral Hepat 2003; 10:197-204. [PMID: 12753338 DOI: 10.1046/j.1365-2893.2003.00427.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Interferon-alpha (IFN) monotherapy results in sustained virological clearance in a minority of patients with chronic hepatitis C. The aim of this study was to assess the effect of a reinforced regimen combining ribavirin and high-dose IFN for 48 weeks compared with a nonreinforced regimen combining a standard IFN regimen and ribavirin for 24 weeks in nonresponders with chronic hepatitis C. A total of 231 patients with chronic hepatitis C and previous nonresponse to IFN monotherapy were randomized. The reinforced group (n = 114) received IFN-2b 6 million units (MU) thrice weekly (TIW) and ribavirin for 48 weeks, and the nonreinforced group (n = 117) received IFN-2b 3 MU TIW and ribavirin for 24 weeks. The main outcome measure was a sustained virological response, defined as negative serum hepatitis C virus (HCV)-RNA 24 weeks following the end of treatment. This endpoint was determined in 98 patients of the reinforced group and 105 patients of the nonreinforced group. At the end of follow-up, a sustained virological response was observed in 29 of the 98 patients (29.6%) in the reinforced group vs 16 of the 105 patients (15.2%) in the nonreinforced group (P = 0.014). In multivariate analysis, factors associated with a sustained virological response were treated with a reinforced regimen [odds ratio (OR) 2.9; P = 0.06] and genotype 2 or 3 (OR 8.8; P < 0.0002). A total of 160 patients had paired biopsies before and after treatment. Histological activity improvement was observed in 32 of 80 patients (40%) and fibrosis worsening in 26 of 80 patients (33%) in the reinforced group vs 13 of 80 (16%) and 19 of 80 (24%) in the nonreinforced group (P = 0.30 and 0.20, respectively). Hence in nonresponders, a high-dose 48-week regimen of IFN and ribavirin combination was more effective than a regimen with interferon at lower dose and ribavirin for 24 weeks only.
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Thomas F, Ulitsky P, Augier R, Dusticier N, Samuel D, Strambi C, Biron DG, Cayre M. Biochemical and histological changes in the brain of the cricket Nemobius sylvestris infected by the manipulative parasite Paragordius tricuspidatus (Nematomorpha). Int J Parasitol 2003; 33:435-43. [PMID: 12705936 DOI: 10.1016/s0020-7519(03)00014-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Hairworms (nematomorpha) alter the behaviour of their insect hosts, making them commit 'suicide' by jumping into an aquatic environment required by the adult parasite for the continuation of its life cycle. To explore the physiological and neuronal basis of this behavioural manipulation, we first performed a biochemical study to quantify different neurotransmitters or neuromodulators (monoamines and amino acids) in the brain of crickets (Nemobius sylvestris) uninfected and infected by the hairworm Paragordius tricuspidatus. We also analysed several polyamines and amino-acids having no known neuromodulatory function. The presence/absence of the parasite explained the largest part of the variation in compound concentrations, with infected individuals displaying on average lower concentrations than uninfected individuals. However, for three amino acids (taurine, valine and tyrosine), a significant part of the variation was also correlated with the manipulative process. In order to compare neurogenesis between infected and uninfected crickets, we also performed a histological study on mushroom bodies in the cricket's brain. The mitotic index exhibited a two-fold increase in infected crickets as compared with uninfected crickets. This is the first study to document changes in the brain of insects infected by nematomorphs.
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Samuel D, Beard S, Yang H, Saunders N, Jin L. Genotyping of measles and mumps virus strains using amplification refractory mutation system analysis combined with enzyme immunoassay: a simple method for outbreak investigations. J Med Virol 2003; 69:279-85. [PMID: 12683419 DOI: 10.1002/jmv.10275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A simple method, based on a modification of the amplification refractory mutation system (ARMS), for genotyping outbreak strains of measles and mumps viruses and detecting these in a simple enzyme immunoassay (EIA) is described. Fifty-three measles strains circulating at the time of an outbreak in London in 2000 and 26 strains circulating at the time of a mumps outbreak in Accrington, UK, in 1999 were investigated. All strains were genotyped by direct sequencing. ARMS primers were then designed to amplify the outbreak strain. The ARMS-EIA for measles and mumps detected all 36 measles outbreak strains as genotype D6, and all 15 mumps outbreak strains as genotype F, respectively. The sensitivity and specificity of both the measles D6 and Mumps F genotype ARMS EIA was 100% compared with direct sequencing. The results show that ARMS-EIA can be used as a rapid alternative to genotyping by direct sequence analysis in outbreak situations.
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Humbert M, Labrune P, Sitbon O, Le Gall C, Callebert J, Hervé P, Samuel D, Machado R, Trembath R, Drouet L, Launay JM, Simonneau G. Pulmonary arterial hypertension and type-I glycogen-storage disease: the serotonin hypothesis. Eur Respir J 2002; 20:59-65. [PMID: 12166582 DOI: 10.1183/09031936.02.00258702] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A case of pulmonary arterial hypertension in a patient with type-Ia glycogen-storage disease, a rare autosomal recessive disorder caused by a deficiency of glucose-6-phosphatase is reported in this study. It has been suggested that the occurrence of pulmonary arterial hypertension in type-Ia glycogen-storage disease could be due to an abnormal production of vasoconstrictive amines such as serotonin. To test this hypothesis, plasma serotonin concentrations were prospectively measured in 13 patients with type-Ia glycogen-storage disease, one patient with severe pulmonary hypertension and type-Ia glycogen-storage disease, 16 patients displaying severe pulmonary arterial hypertension, and 26 normal healthy controls. Elevated plasma serotonin concentrations were found in patients with either severe pulmonary arterial hypertension (38.8+/-7.3 nmol x L(-1)) or type-Ia glycogen-storage disease (36.8+/-11.5 nmol x L(-1)), as compared with controls (8.8+/-0.6 nmol x L(-1), p<0.001). Plasma serotonin was dramatically elevated in the patient with type-Ia glycogen-storage disease and pulmonary arterial hypertension (113.4 nmol x L(-1)). It is concluded that type-Ia glycogen-storage disease may be another condition in which abnormal handling of serotonin is one event in a multistep process leading to severe pulmonary arterial hypertension.
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Guillet B, Lortet S, Masmejean F, Samuel D, Nieoullon A, Pisano P. Developmental expression and activity of high affinity glutamate transporters in rat cortical primary cultures. Neurochem Int 2002; 40:661-71. [PMID: 11900862 DOI: 10.1016/s0197-0186(01)00110-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The expression and activity of glutamate transporters (EAAC1, GLAST and GLT1) were examined during the development of cortical neuron-enriched cultures. Protein content and mitochondrial respiration both increased during the first 7 days, later stabilized and decreased from DIV14. Glutamate transport and extracellular concentration were relatively constant from DIV3 to 18. The kinetic parameters of glutamate transport were at DIV7: K(m)=19+/-3 microM and V(max)=1068+/-83 pmol/mg protein/min and at DIV14: K(m)=40.8+/-9.3 microM and V(max)=1060+/-235 pmol/mg protein/min. The shift in K(m) towards higher values suggest a more important participation of GLAST after DIV14. At DIV7 and 14, glutamate transport was poorly sensitive to dihydrokaïnate (DHK) suggesting a weak participation of GLT1 in glutamate transport. Western blot experiments and immunocytochemistry showed that EAAC1 was expressed by neurons whatever the stage of the culture. GLAST was found in astrocytes as soon as DIV3 and labeling increased during the development of the culture. There was little neuronal GLT1 immunoreactivity at DIV7, only detected by immunocytochemistry. From DIV10 to 18, an increasing astrocytic expression of GLT1 was observed, also detected by Western blotting. These results show that: (1) glutamate uptake remains stable all along the development of the cultures although the pattern of expression of the different transporters is changing, suggesting that glutamate transport is highly regulated; (2) neuronal EAAC1 may play a critical role during the early stages of the culture when it is expressed alone; and (3) the developmental expression pattern of glutamate transporters in cortical neuron-enriched cultures is quite similar to that observed in vivo during early postnatal development.
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