Article: Temporal distribution of positive results of tests for detecting Leishmania infection in stray dogs of an endemic area of visceral leishmaniasis in the Brazilian tropics: A 13 years survey and association with human disease.Deborah B M Fraga, Manuela S Solcà, Virgínia M G Silva, Lairton S Borja, Eliane G Nascimento, Geraldo G S Oliveira, Lain C Pontes-de-Carvalho, Patrícia S T Veras, Washington L C Dos-Santos[show abstract] [hide abstract]
ABSTRACT: Human visceral leishmaniasis occurs in periodic waves in endemic areas of Brazil. In this study we followed the prevalence of human visceral leishmaniasis and of Leishmania infantum infection in stray dogs of an endemic area of visceral leishmaniasis at periods of time between 1997 and 2010. Prevalence of human visceral leishmaniasis had two peaks (40 cases) in 1997 and 2006 with sharp declines to 2 cases in 2001 and to 5 cases in 2008. Similar fluctuations were also observed in the occurrence of positive spleen culture and anti-Leishmania serology in dogs, although the proportion of dogs with active spleen parasitism remained relatively high even in the periods of low prevalence of human disease. These observations support the notion that stray dogs may constitute a renewable source of parasites, capable of sustaining the persistence of the infection in urban areas, even in periods of low transmission by phlebotomines.Veterinary Parasitology 06/2012; · 2.58 Impact Factor
Article: Semiquantitative and semi-automated morphometric evaluation of chronic lesions in renal biopsiesDaniel Abensur Athanazio, Gloria Maria Maranhão Sweet, Carlos Alberto Silva, Washington Luis Conrado dos-Santos[show abstract] [hide abstract]
ABSTRACT: Chronic lesions in renal biopsies are a well recognized prognostic factor for renal diseases, including lupus nephritis. The methods used for assessment of chronic lesions are, however, largely based on semiquantitative evaluation and may lead to poor reproducibility. Interobserver variation is particularly important in lupus nephritis, in which acute and chronic lesions may occur simultaneously. In this study we tested the reproducibility of chronic lesion assessment performed by three pathologists, two with specific training in renal pathology, using 20 renal biopsies and a standard semiquantitative method. In a second experiment, we evaluated the reproducibility of chronic lesion assessment in 33 biopsies of lupus nephritis by the two nephropathologists. The semiquantitative estimated values were compared with those from a previously proposed morphometric method for quantification of chronic lesions in renal biopsies. Although correlations were observed among the estimated values, there was a wide range of variation when semiquantitative methods were used. In particular, activity and chronicity indices of lupus nephritis were poorly reproducible. In contrast, use of a morphometric score, although not eliminating interobserver variability, led to better reproducibility of estimated values than that obtained with semiquantitative methods.International Urology and Nephrology 04/2012; 41(3):643-651. · 1.47 Impact Factor
Article: A monoclonal antibody against a canine CD45 homologue: analysis of tissue distribution, biochemical properties and in vitro immunological activity.Paulo Henrique Palis Aguiar, Stella Maria Barrouin-Melo, Carlos Roberto Franke, Roberto Robson Borges dos Santos, Tânia Maria Correia Silva, José O Mengel, Washington Luis Conrado dos-Santos, Lain Pontes-de-Carvalho[show abstract] [hide abstract]
ABSTRACT: This report describes the characterisation of a monoclonal antibody (mAb), AB6, which recognises specifically a cluster of canine leukocyte surface molecules. The immunogen used for obtaining the AB6 mAb was a lysate of canine peripheral blood mononuclear cells (PBMC). This novel mAb belongs to the IgG2a isotype, and reacted in Western blot with four different canine leukocyte glycoproteins with apparent molecular weights of 180, 190, 205 and 220 kDa. The AB6 mAb recognised the majority of canine peripheral blood leukocytes as determined by flow cytometry (97%). It also exhibited a broad reactivity pattern against lymphoid and myeloid cells, inhibited the proliferation of mitogen-stimulated canine PBMC and did not recognise human PBMC and murine splenocytes. The biochemical properties, cell and tissue specificity, and in vitro biological activity of the AB6 mAb indicate that it recognises a canine CD45 homologue. The mAb could become a valuable diagnostic and research tool for the evaluation of immune functions in dogs.The Veterinary Journal 02/2007; 173(1):158-66. · 2.24 Impact Factor
Paulo Henrique Palis Aguiar, Roberto Robson Borges dos Santos, Daniela Farias Larangeira, Marta Almeida dos Santos, Stella Maria Barrouin-Melo, Tânia Maria Correia Silva, José O Mengel, Washington Luis Conrado dos Santos, Lain Pontes-de-Carvalho[show abstract] [hide abstract]
ABSTRACT: The production and partial characterization of a monoclonal antibody, the IgG1 IH1, which recognizes an antigen distributed in canine monocytes/macrophages, is reported here. The distribution and apparent molecular weight of the antigen recognized by the IH1 MAb was determined in peripheral blood leukocytes, peripheral blood monocyte-derived macrophages and tissue sections of spleen, liver and skin, using Western blotting, immunocytochemistry, immunohistochemistry and flow cytometry. The IH1 MAb-recognized antigen was detected in Western blotting under non-reducing conditions spread out as a large band covering the position corresponding to the migration of molecules with molecular weights from 55 to 73 kDa. The IH1 MAb labeled blood monocytes, tissue macrophages in lymph nodes, and in the mantle zone of the spleen, and Kupffer cells in the liver. It did not react with human cells. In flow cytometric analysis, the IH1 MAb reacted with a subpopulation of monocytes. The MAb described herein may become a valuable tool for diagnosis and research on canine diseases.Hybridoma and Hybridomics 09/2004; 23(4):250-7.
Paulo Henrique Palis Aguiar, Roberto Robson Borges dos Santos, Carla Andrade Lima, Hilton Rios de Sousa Gomes, Daniela Farias Larangeira, Patrícia Meira Santos, Stella Maria Barrouin-Melo, Washington Luis Conrado dos-Santos, Lain Pontes-de-Carvalho[show abstract] [hide abstract]
ABSTRACT: A panel of anti-canine leukocyte monoclonal antibodies (MAbs) was produced by immunizing BALB/c mice with canine peripheral blood mononuclear cells (PBMC), either resting or stimulated with concanavalin A (ConA). Three out of 28 clones-IH1, AB6, and HG6-screened by ELISA and producing antibody with the highest specificity for canine cell immunostaining, were subjected to three subsequent subcloning steps by limiting dilution, and selected for further characterization. These MAbs belonged to IgG1 (HG6 and IH1) and IgG2a (AB6) isotypes. The distribution of cell populations expressing the antigen recognized by the antibodies was identified by indirect immunoflorescence on canine PBMC and on tissue sections of lymph node, spleen, liver and skin. The possible crossreactivity with human PBMC was also examined in immunocytochemistry. One of the antibodies specifically recognized macrophages. The MAbs presented here can be foreseen as possible valuable diagnostic and research tools to study immune functions in dogs.Hybridoma and Hybridomics 05/2004; 23(2):127-32.