Navegando por Autor "Costa, Carlos Alberto da"
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Item Comparative evaluation of phenol and thimerosal as preservatives for a candidate vaccine against American cutaneous leishmaniasis.(2010) Mayrink, Wilson; Tavares, Carlos Alberto Pereira; Deus, Rosângela Barbosa de; Pinheiro, Melina Barros; Guimarães, Tânia Mara Pinto Dabés; Andrade, Hélida Monteiro de; Costa, Carlos Alberto da; Toledo, Vicente de Paulo Coelho Peixoto deFor decades thimerosal has been used as a preservative in the candidate vaccine for cutaneous leishmaniasis, which was developed by Mayrink et al. The use of thimerosal in humans has been banned due to its mercury content. This study addresses the standardization of phenol as a new candidate vaccine preservative. We have found that the proteolytic activity was abolished when the test was conducted using the candidate vaccine added to merthiolate (MtVac) as well as to phenol (PhVac). The Montenegro’s skin test conversion rates induced by MtVac and by PhVac was 68.06% and 85.9%, respectively, and these values were statistically significant (p < 0.05). The proliferative response of peripheral mononuclear blood cells shows that the stimulation index of mice immunized with both candidate vaccines was higher than the one in control animals (p < 0.05). The ability of the candidate vaccines to induce protection in C57BL/10 mice against a challenge with infective Leishmania amazonensis promastigotes was tested and the mice immunized with PhVac developed smaller lesions than the mice immunized with MtVac. Electrophoresis of phenol-preserved antigen revealed a number of proteins, which were better preserved in PhVac. These results do in fact encourage the use of phenol for preserving the immunogenic and biochemical properties of the candidate vaccine for cutaneous leishmaniasis.Item Comparison of polymerase chain reaction with other laboratory methods for the diagnosis of American cutaneous leishmaniasis Diagnosis of cutaneous leishmaniasis by polymerase chain reaction.(2006) Marques, Marcos José; Volpini, Ângela Cristina; Coelho, George Luiz Lins Machado; Pinto, Jackson Machado; Costa, Carlos Alberto da; Mayrink, Wilson; Genaro, Odair; Romanha, Alvaro JoséAn evaluation of 5 laboratory methods for diagnosing American cutaneous leishmaniasis (ACL) was carried out on patients from an endemic area of Brazil. From 164 patients presenting cutaneous lesions, and suspected to have ACL, 133 (81.1%) were confirmed for the disease by Montenegro skin test (MST) and/or parasitologic examination (PE). In both groups of patients, the positivity of polymerase chain reaction (PCR) was similar to that of immunofluorescence assay and enzyme-linked immunosorbent assay, and higher than that of MST and PE ( P b .05). In the group of patients suspected to have ACL, PCR presented the same positivity as PE and MST together. No correlation between positivity of the laboratory methods and clinical or epidemiologic aspects was observed. Our data confirmed the value of PCR as an alternative laboratory method for diagnosing ACL, especially for those patients with negative PE and MST.Item Epidemiology of canine visceral leishmaniasis in the endemic area of Montes Claros Municipality, Minas Gerais State, Brazil.(2003) Silva, João Carlos França da; Costa, Roberto Teodoro da; Siqueira, Ari M.; Coelho, George Luiz Lins Machado; Costa, Carlos Alberto da; Mayrink, Wilson; Vieira, Edvá P.; Silva, Jaime Costa daThe Montes Claros City is located in an endemic area for visceral leishmaniosis in the Minas Gerais State, Brazil.With the implementation of a program for the control of visceral leishmaniosis in 1994, a sectional study was carried out to evaluate the infection by viscerotropic Leishmania in the population of dogs from Montes Claros, basically using indirect immunofluorescence antibody test (IFAT). Blood samples were collected on filter paper from 33,937 dogs, representing 96.1% of the canine local population. The prevalence for visceral leishmaniosis was found to be 9.7% in the municipality, being 9.9% in the urban area and 8.8% in the rural area. The annual incidence showed to be 64.3/1000 dogs. Prevalence of infection was not correlated with dogs age. The most affected breeds were: Boxer (24.6%) and Cocker (26.9%); Mongrel dogs had a prevalence of 7.8%. Short-hair animals had a prevalence of 11.9%, while long-furred animals had a prevalence of 8.9%. The isoenzymatic profile indicated that Leishmania (Leishmania) chagasi was the visceral leishmaniosis etiological agent in Montes Claros City, Minas Gerais State, Brazil. The main geographical areas for the parasite transmission were identified, and control measures were immediately started. The role of the dog as a reservoir for L. chagasi was confirmed. It was demonstrated that short-furred animals are at a higher risk of acquiring visceral leishmaniosis than the long-furred dogs.Item Immuno-biochemical evaluations of phenol and thimerosal as antigen preservatives in Montenegro skin test.(2006) Mayrink, Wilson; Coelho, George Luiz Lins Machado; Guimarães, Tânia Mara Pinto Dabés; Andrade, Hélida Monteiro de; Peres, Elúzia de Castro; Costa, Carlos Alberto da; Toledo, Vicente de Paulo Coelho Peixoto deMontenegro skin test (MST) represents the main complementary diagnostic test for tegumentary leishmaniases (TL) in endemic regions. Most antigen formulations used for the MST contain thimerosal as preservative. The Food and Drug Administration (FDA), however, recommended reducing or eliminating thimerosal from vaccines and other biological reagents and the Agˆencia Nacional de Vigilˆancia Sanit´aria (ANVISA) in Brazil, prohibited the use of mercurial compounds in immunobiologicals. In the search for an alternative stabilizer, phenol and thimerosal were tested as antigen preservatives in MST. Formulations were tested when fresh and after a 12-month storage at 4 ◦C in TL confirmed mice and human patients, and were evaluated for protein constitution by SDS-PAGE, Western blot and anti-gp63 ELISA. In mice, a decrease in the diagnostic effectiveness in merthiolate formulation was observed after a 12-month storage. SDS-PAGE, Western blot and anti-gp63 ELISA analyses showed a degradation of antigen proteins in both formulations after 12-month storage and that phenol-preserved antigen was quantitatively and qualitatively better than the merthiolate-preserved one. In patients, the average of induration diameter was larger in fresh antigens (p < 0.05). However, storage time did not jeopardize their diagnostic capacity.No non-specific reactions produced by phenol or merthiolate were observed neither in humans nor in mice. Phenol could be a good alternative to replace the merthiolate in MST, and despite the proteolytic activity, antigens remain viable for at least 12 months.Item Immunochemotherapy in american cutaneous leishmaniasis : immunological aspects before and after treatment.(2001) Toledo, Vicente de Paulo Coelho Peixoto de; Mayrink, Wilson; Gollob, Kenneth John; Oliveira, Milton Adriano Pelli de; Costa, Carlos Alberto da; Genaro, Odair; Pinto, J. A.; Afonso, Luís Carlos CroccoIn this study, we evaluated the immune response of patients suffering from cutaneous leishmaniasis treated with two distinct protocols. One group was treated with conventional chemotherapy using pentavalent antimonium salts and the other with immunochemotherapy where a vaccine against cutaneous leishmaniasis was combined with the antimonium salt. Our results show that, although no differences were observed in the necessary time for complete healing of the lesions between the two treatments, peripheral blood mononuclear cells from patients treated by chemotherapy showed smaller lymphoproliferative responses at the end of the treatment than those from patients in the immunochemotherapy group. Furthermore, IFN-production was also different between the two groups. While cells from patients in the chemotherapy group produced more IFN-at the end of treatment, a significant decrease in this cytokine production was associated with healing in the immunochemotherapy group. In addition, IL-10 production was also less intense in this latter group. Finally, an increase in CD8+ -IFN-producing cells was detected in the chemotherapy group. Together these results point to an alternative treatment protocol where healing can be induced with a decreased production of a potentially toxic cytokine.Item Immunotherapy, immunochemotherapy and chemotherapy for American cutaneous leishmaniasis treatment.(2006) Mayrink, Wilson; Botelho, Ana Cristina de Carvalho; Magalhães, Paulo Araújo; Batista, Sebastião Mariano; Lima, Antonio de Oliveira; Genaro, Odair; Costa, Carlos Alberto da; Melo, Maria Norma; Michalick, Marilene Susan Marques; Williams, Paul; Dias, Magno; Caiaffa, Waleska Teixeira; Nascimento, Evaldo do; Coelho, George Luiz Lins MachadoO tratamento de primeira escolha para leishmaniose tegumentar americana é o antimonial pentavalente. Embora este tratamento seja na maioria das vezes efetivo e indicado, devem ser consideradas as desvantagens tais como efeitos colaterais, longa duração do tratamento e contra-indicação para cardiopatas, nefropatas, idosos, grávidas e outras condições. Com o advento da vacina antileishmaniose tegumentar americana para fins profiláticos e terapêuticos, associando-a ou não a outros fármacos, muitas pesquisas têm sido desenvolvidas, sendo a vacina a principal entre os atuais recursos no tratamento e prevenção da leishmaniose tegumentar americana. Em conclusão, a associação do antimônio com a vacina (imunoquimioterapia) apresentou o mesmo índice de cura em relação ao tratamento padrão (100%), e ainda reduziu o volume do sal em 17,9% e o tempo de cura significativamente, de 87 para 62 dias; conseqüentemente, reduzindo os efeitos colaterais.Item Leishmaniose visceral canina : avaliação da metodologia sorológica utilizada em inquéritos epidemiológicos.(1991) Costa, Carlos Alberto da; Genaro, Odair; Lana, Marta de; Magalhães, Paulo Araújo; Dias, Magno; Michalick, Marilene Susan Marques; Melo, Maria Norma; Costa, Roberto Teodoro da; Rocha, Neuza Maria de Magalhaes; Mayrink, WilsonFoi realizado um estudo comparativo da reação de imunofluorescencia indireta em eluatos de sangue de cães infectados experimentalmente com diferentes tripanosomatideos. Utilizaram-se como antigenopromastigotas de L. mexicana, L. braziliensis e L. chagasi. Os resultados mostraram que a sensibilidade do método foi de 87,5% para o diagnostico do calazar canino, independentemente do antígeno empregado; e que ocorre reação cruzada com Leishmaniose tegumentar em 75% dos casos e com doença de Chagas em 83,3%. Levantamento epidemiológico em área de leishmaniose confirma que a reação de imunofluorescencia em eluatos de sangue canino fornece reações cruzadas em cães infectados com Leishmania braziliensis e L. chagasi. Não se verificou reação cruzada pela RFC. Sugere-se a utilização da reação de imunofluorescencia nas campanhas de saúde publica, mas e de se chamar a atenção para o fato de que as taxas de positividade não devem ser utilizadas como indicadores da prevalência do calazar canino.Item Vaccination of C57BL/10 mice against cutaneous leishmaniasis using killed promastigotes of different strains and species of Leishmania.(2002) Mayrink, Wilson; Santos, Gilmara Cristina dos; Toledo, Vicente de Paulo Coelho Peixoto de; Guimarães, Tânia Mara Pinto Dabés; Coelho, George Luiz Lins Machado; Genaro, Odair; Costa, Carlos Alberto daAntigenic extracts from five Leishmania stocks were used to vaccinate C57BL/10 mice. The Leishvacinand PH8 monovalent vaccine yielded the highest IFN-levels in the supernatants of spleen cell culture from vaccinated animals. Each single strain immunized group showed evidence of protective immunity six months after the challenge with promastigotes of Leishmania (Leishmania) amazonensis. No differences were detected between the vaccinated groups. It can be concluded that vaccines composed of single Leishmania stocks can provide protection to C57BL/10 mice against L. (L.) amazonensis infection.Item Vaccine for prophylaxis and immunotherapy, Brazil.(1996) Genaro, Odair; Toledo, Vicente de Paulo Coelho Peixoto de; Costa, Carlos Alberto da; Hermeto, Marco Victor; Afonso, Luís Carlos Crocco; Mayrink, Wilson