Mast cells (MCs) are main effector cells in allergic inflammation and after activation, they release stored (histamine, heparin, proteases) and newly synthesized (lipid mediators and cytokines) substances. In the gastrointestinal tract the largest MC population is located in the lamina propria and submucosa whereas several signals such as the cytokine IL-4, seem to increase the granule content and to stimulate a remarkable expansion of intestinal MCs. The broad range of MC-derived bioactive molecules may explain their involvement in many different allergic disorders of the gastrointestinal tract.
View Article and Find Full Text PDFThe golden hamster is a suitable model for studying cutaneous leishmaniasis (CL) due to () Immunopathological mechanisms are well established in the -mouse model, in which IL-4 instructs a Th2 response towards progressive infection. In the present study, we evaluated the natural history of infection from its first stages up to lesion establishment, with the aim of identifying immunological parameters associated with the disease outcome and parasitism fate. To this end, hamsters infected with 10, 10, or 10 promastigotes were monitored during the first hours (4h, 24h), early (15 days, 30 days) and late (50 days) post-infection (pi) phases.
View Article and Find Full Text PDFTransfusion-transmitted leishmaniasis has been a concern in regions endemic for the disease. Whether immediate or delayed, the risks posed by this mode of transmission call for careful assessment. The purpose of this study was to detect Leishmania infection in blood donors living in an endemic area and to investigate progression to the disease in these individuals.
View Article and Find Full Text PDFThe purpose of this study was to estimate the prevalence of intestinal parasites in both cooperative-affiliated and independent waste pickers operating at the municipal sanitary landfill in Campo Grande, Mato Grosso do Sul, Brazil, and associate these findings with hemoglobin, eosinophils, vitamin A and C levels and interleukin 5 and 10 (IL-5 and IL-10) production. Biological samples were collected, in addition to clinical, epidemiological, and sociodemographic data. Stool analyzes were based on sedimentation by centrifugation and on spontaneous sedimentation.
View Article and Find Full Text PDFBackground: Leishmania (Viannia) braziliensis is the main etiological agent of tegumentary leishmaniasis in the Americas. Parasite molecular diversity and host immune status contribute to extensive variations in its clinical presentation within endemic areas of Brazil. Pentavalent antimonials have been used for more than 60 years as the first-line drug for all cases, despite the potential for severe side effects and refractoriness.
View Article and Find Full Text PDFMem Inst Oswaldo Cruz
August 2013
Leishmania RNA virus (LRV) has been shown to be a symbiotic component of Leishmania parasites in South America. Nested retro-transcription polymerase chain reaction was employed to investigate LRV1 presence in leishmaniasis lesions from Brazil. In endemic areas of Rio de Janeiro (RJ), no LRV1 infection was observed even with mucosal involvement.
View Article and Find Full Text PDFAlthough several studies have evaluated the role of p16(INK4a) as a diagnostic marker of cervical intraepithelial neoplasia (CIN) and its association with disease progression, studies regarding the role of p16(INK4a) in human immunodeficiency virus (HIV)-infected patients remain scarce. The present study was designed to determine the potential utility of p16(INK4a) as a diagnostic marker for CIN and invasive cervical cancer in HIV-positive and negative cervical specimens. An immunohistochemical analysis of p16(INK4a) was performed in 326 cervical tissue microarray specimens.
View Article and Find Full Text PDFBackground: Leishmaniases control has been hampered by the unavailability of rapid detection methods and the lack of suitable therapeutic and prophylactic measures. Accurate diagnosis, which can distinguish between Leishmania isolates, is essential for conducting appropriate prognosis, therapy and epidemiology. Molecular methods are currently being employed to detect Leishmania infection and categorize the parasites up to genus, complex or species level.
View Article and Find Full Text PDFDiagn Microbiol Infect Dis
December 2010
The aim of this study was to investigate Clostridium difficile-associated diarrhea (CDAD) in an intensive care unit (ICU) of a tertiary hospital in Rio de Janeiro, Brazil, and to characterize epidemiologically C. difficile strains obtained from an outbreak of CDAD. Within almost a 4-year surveillance period, CDAD incidence was determined for the first time in Brazil, and a 3-fold increase was observed in the average rate of CDAD, featuring an outbreak.
View Article and Find Full Text PDFBackground: American tegumentary leishmaniasis (ATL) caused by Leishmania (Viannia) braziliensis is endemic in Rio de Janeiro State (RJ), where the disease shows epidemiologic and clinical characteristics distinct from those of ATL in other Brazilian regions. Paraty is the second most important endemic area in RJ; however, reports on leishmaniasis in this region refer to the occurrence of the disease without describing its characteristics.
Methods: The clinical features of 71 cases of ATL reported between 1991 and 1997 in Paraty are presented.
Production of extended-spectrum beta-lactamases (ESBLs) has been reported in virtually all species of Enterobacteriaceae, which greatly complicates the therapy for infections caused by these organisms. However, the frequency of isolates producing AmpC beta-lactamases, especially plasmid-mediated AmpC (pAmpC), is largely unknown. These beta-lactamases confer resistance to extended-spectrum cephalosporins and aztreonam, a multidrug-resistant (MDR) profile.
View Article and Find Full Text PDFTo evaluate risk factors for colonization or infection due to multidrug-resistant Pseudomonas aeruginosa (MDRPa) carrying the bla(SPM) gene (SPM-MRDPa) among hospitalized patients, we undertook a case control study at a 480-bed, tertiary-care university hospital. Two different case definitions were used. In the first definition, a case patient (SPM case patient) was defined as a patient who had at least one isolate of SPM-MDRPa (14 patients).
View Article and Find Full Text PDFBackground: From 1990 to 1995 at Hospital Universitário Clementino Fraga Filho, patients colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) were treated with mupirocin to eliminate MRSA carriage. In 1995, 65% of MRSA patients at this hospital had mupirocin-resistant isolates. Starting in 1996, mupirocin use was restricted to patients colonized, but not infected, with MRSA.
View Article and Find Full Text PDFHerein we investigate the ability of live promastigotes and total lysate of Leishmania (Viannia) braziliensis, derived from parasites in the logarithmic (L-Lb) or stationary phase (S-Lb), to induce human mast cell line (HMC-1) activation. In comparison with medium-treated cells, a significant histamine release was observed in HMC-1 cultures stimulated with S-Lb. Lipophosphoglycan also induced histamine release by HMC-1 cells.
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