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S Barete

Publications and source records attributed to S Barete.

At least 19 recordsLinked to original sources
PubMed2005

[Systemic mastocytosis].

Systemic mastocytosis is characterized by abnormal mast cell proliferation in different organs. The 2001 consensus classification distinguishes in separate categories indolent systemic mastocytosis, systemic mastocytosis with concomitant blood disease, aggressive systemic mastocytosis and mast cell leukemia. Clinical manifestations are caused by tissue infiltration by proliferating mastocytes and by release of mediators. The principal organs affected are the skin, bones, digestive tract, liver, spleen and lymph nodes. Diagnosis of mastocytosis is based on appropriate stains (Giemsa, toluidine blue) and immunophenotype features (tryptase, CD117, also known as c-KIT and stem cell factor receptor). Serum tryptase levels reflect the total mast cell burden. Treatment must prevent release of mast cell mediators (histamine antagonists, cromolyn sodium, corticosteroids, or leukotriene-receptor inhibitors), limit bone involvement (bisphosphonates) and reduce the number of circulating mast cells (interferon, cladribine, or tyrosine kinase inhibitors). Enhanced understanding of the pathogenic mechanisms (mutation of c-kit and platelet-derived growth factor receptor alpha has led to the development of targeted treatments, including new inhibitors of tyrosine kinase and of nuclear factor Kappa B.

Benzamides↗
PubMed2005

Molecular characterization of the idiopathic hypereosinophilic syndrome (HES) in 35 French patients with normal conventional cytogenetics.

Idiopathic hypereosinophilic syndrome (HES) characterized by unexplained and persistent hypereosinophilia is heterogeneous and comprises several entities: a myeloproliferative form where myeloid lineages are involved with the interstitial chromosome 4q12 deletion leading to fusion between FIP1L1 and PDGFRA genes, the latter acquiring increased tyrosine kinase activity. And a lymphocytic variant, where hypereosinophilia is secondary to a primitive T lymphoid disorder demonstrated by the presence of a circulating T-cell clone. We performed molecular characterization of HES in 35 patients with normal karyotype by conventional cytogenetic analysis. TCRgamma gene rearrangements suggesting T clonality were seen in 11 (31%) patients, and FIP1L1-PDGFRA by RT-PCR in six (17%) of 35 patients, who showed no evidence of T-cell clonality. An elevated serum tryptase level was observed in FIP1L1-PDGFRA-positive patients responding to imatinib, whereas serum IL-5 levels were not elevated in T-cell associated hypereosinophilia. Sequencing FIP1L1-PDGFRA revealed scattered breakpoints in FIP1L1-exons (10-13), whereas breakpoints were restricted to exon 12 of PDGFRA. In the 29 patients without FIP1L1-PDGFRA, no activating mutation of PDGFRA/PDGFRB was detected; however; one patient responded to imatinib. FISH analysis of the 4q12 deletion was concordant with FIP1L1-PDGFRA RT-PCR data. Further investigation of the nature of FIP1L1-PDGFRA affected cells will improve the classification of HES.

Adolescent↗
PubMed2004

[Scurvy].

Explore the source record for details and available documents.

Adult↗
PubMed2003

[Treatment of systemic mastocytosis].

BACKGROUND: Systemic mastocytosis is a rare disease, characterized by mast cells proliferation in various organs. Two types of clinical manifestations can be distinguished: those related to mast cells mediators release and those related to tumoral proliferation involving different organs, these later defining aggressive systemic mastocytosis. Until recently, treatment was mainly symptomatic, without anti tumoral effect. RECENT FACTS: These last years, advances have been made in the understanding of the disease with the discovery of the c-kit oncogene mutation and the approach of the disease as a myeloproliferative disorder. PERSPECTIVES: Based on experiences acquired in the treatment of this kind of disorders, evaluation of new therapeutics, such as cladribine or combination of interferon-alpha and cytarabine is in progress. At least, tyrosine kinase inhibitors, a new family of molecules, are able of inhibiting some types of the mutated c-kit protein and one of them, imatinib mesylate, has shown a great efficacy in the treatment of gastro intestinal stromal tumors (GIST) which also involves the c-kit mutation. By analogy, treatment of patients with c-kit susceptible mutation might be treated with this molecule.

Adrenal Cortex Hormones↗
PubMed2001

Human herpesvirus-8 seroconversions after renal transplantation.

BACKGROUND: Human herpesvirus-8 (HHV-8) is a new human herpesvirus that is clearly associated with Kaposi's sarcoma (KS). A previous study has reported that the prevalence of KS in a cohort of renal transplant recipients with previous HHV-8 infection was 28% and two other studies have shown that KS can be linked to HHV-8 seroconversion after graft. The aim of this study was to evaluate the HHV-8 seroconversion rate in a cohort of renal allograft recipients in Paris. METHODS: Two hundred eighty-seven patients who were HHV-8 seronegative before renal transplantation were tested for HHV-8 antibodies by an immunofluorescence assay 12 months after transplantation. RESULTS: Of the 287 patients, 6 (2.09%) seroconverted after renal transplantation. None of these 6 patients developed KS within 3 years of the first HHV-8 positive serum. None of the clinical manifestations that could be associated with HHV-8 primary infection were observed during the seroconversion. CONCLUSIONS: Our results demonstrated that HHV-8 seroconversion can be observed even in a low HHV-8 prevalence area and confirmed the need to perform systematic screening for HHV-8 antibodies in renal graft donors and recipients.

Adult↗
PubMed2000

Outcome of kidney transplant recipients with previous human herpesvirus-8 infection.

BACKGROUND: The consequences of a prior human herpesvirus-8 (HHV-8) infection in kidney-transplant recipients are still partially unknown. The aim of this monocentric study was to determine the prevalence of HHV-8-seropositive patients at the time of transplantation and to identify the main clinical events of these HHV-8+ recipients. METHODS: From January 1, 1990 to December 31, 1996, antibodies to HHV-8 latent nuclear antigen were detected by indirect immunofluorescent method in serum samples collected just before kidney transplantation from 400 consecutive patients. Conventional double or triple immunosuppressive treatment was prescribed. For the group of HHV-8+ recipients, data including death rate, graft survival, and occurrence of Kaposi's sarcoma (KS) were retrospectively collected until December 31, 1998. Cofactors associated with KS were studied in univariate and multivariate analyses using a Cox model. RESULTS: Thirty-two patients (8%) had antibodies to HHV-8 in their sera at the time of transplantation. Among these 32, 3 years after transplantation, graft survival was 72%, and KS prevalence was 28% (KS incidence: 8.2/yr/100 HHV-8+ recipients). Multivariate analysis identified bacterial and/or Pneumocystis carinii infection (odds ratio: 8.6; P=0.019) and female gender (odds ratio: 5.34; P=0.047) as factors associated with KS. No KS was observed in patients without anti-HHV-8 antibodies at the time of transplantation. CONCLUSIONS: The low graft survival and the high prevalence of KS within the studied population of HHV-8+ transplant recipients are strong arguments for systematic screening of HHV-8 serologic features before transplantation, especially in patients of African origin. HHV-8+ transplant recipients should be closely monitored to severe infections.

Adult↗
PubMed2000

Clinical features and contribution of virological findings to the management of Kaposi sarcoma in organ-allograft recipients.

OBJECTIVES: To describe the clinical features of Kaposi sarcoma (KS) in organ-allograft recipients and to determine the contribution of human herpesvirus 8 (HHV-8) investigations to the management of KS. DESIGN, SETTING, AND PATIENTS: We examined 20 organ-allograft recipients with KS at Pitié-Salpêtrière Hospital, Paris, France, between November 1, 1991, and May 31, 1999. METHODS: We detected HHV-8 antibodies using an indirect immunofluorescence assay and the HHV-8 DNA genome using nonnested polymerase chain reaction with KS-associated herpesvirus 330(233) primers in peripheral blood mononuclear cells collected at transplantation and KS diagnosis. We detected the HHV-8 genome in involved and uninvolved tissue specimens and in 10 patients' serum samples collected 1 month before the first manifestation of KS. We determined the HHV-8 double-strand DNA sequence and subtypes of open reading frame 26. INTERVENTION: Management of KS consisted of progressively tapering immunosuppressive therapy regardless of KS dissemination. Associated infections were treated when possible. Chemotherapy was prescribed only when a functional disability persisted, and polychemotherapy was prescribed for life-threatening disease. MAIN OUTCOME MEASURES: Percentage of recipients with KS remission and stabilization, organ-graft survival, and death rates. RESULTS: Remission of KS was obtained in 9 (45%) of the 20 patients independently of disease dissemination, with a mean follow-up of 35 months. The kidney graft survived in 12 (67%) of the 18 patients. Only 1 patient (5%) died of KS progression. All allograft recipients had anti-HHV-8 antibodies before transplantation. We detected HHV-8 DNA in all involved tissue samples but not in serum samples 1 month before KS onset. The most prevalent subtype was HHV-8 C (9 [53%] of 17 patients) and was not associated with extradermatological extension of KS compared with subtypes A and B'. CONCLUSIONS: Virological investigations of HHV-8 contribute poorly to KS management. Prospective studies are needed to determine the role of HHV-8 virological investigations and to identify associated cofactors so as to prevent KS in organ-allograft recipients.

Adult↗
PubMed2000

[Mycobacterium ulcerans infection].

Mycobacterium ulcerans infection, or Buruli ulcer, is the third most common mycobacterial disease of the immunocompetent host in the tropical areas. M. ulcerans reservoir is aquatic. Infection occurs in children and young adults. The lesion begins with an indolent subcutaneous nodule, principally located on the limbs, that progressively changes into a deep indolent extensive ulcer. M. ulcerans produces a lipidic necrotic and immunosuppressive toxin, named mycolactone, that causes the clinical lesions. In endemic areas, clinical diagnosis is confirmed by microscopic examination. Spontaneous healing occurs after several months or years, causing retractile scars. Surgical excision and grafting is the treatment of choice. Antibiotic therapy is of limited value.

Adult↗
PubMed1999

[Human herpesvirus 8 (HHV-8)].

Human herpesvirus 8 (HHV-8) is associated with all epidemiological forms of Kaposi's sarcoma (KS), multicentric Castleman's disease and primary effusion lymphomas. HHV-8 is a gamma herpesvirus and his genome consists of an estimated 140 kb long unique coding region. Sero-epidemiologic studies support the findings that infection by HHV-8 in the occidental countries is not ubiquitous. The main routes of transmission for HHV-8 is sexual contact at least in homo-sexual men, however distribution of the prevalence of HHV-8 in Africa suggests that this virus could be transmitted by other ways such as mother to child or child to child. Analysis of the genome of HHV-8 identified an imprecedent numbers of genes implicated in cellular growth which have potentially a major role in tumorogenesis. Morphologic studies based on electron-microscopy, immunohistochemistry and in situ hybridization suggest that most of the cells in HHV-8-related tumours are latently infected. Efforts must concentrate on finding the best systems for growing the virus in cell cultures and in the strategy of treatment and (or) prevention of HHV-8-related tumours especially in organ transplant patients.

Adult↗