DEACL - Departamento de Análises Clínicas

Permanent URI for this community

https://monog.ufop.br/handle/123456789/525

Browse

Now showing 1 - 20 of 286

Fase crônica cardíaca fibrosante da Tripanossomíase cruzi experimental no cão.
(1988) Lana, Marta de; Tafuri, Washington Luiz; Caliari, Marcelo Vidigal; Bambirra, Eduardo Alves; Chiari, Cléa de Andrade; Leite, Virginea Hora Rios; Barbosa, Alfredo José Afonso; Toledo, Max Jean de Ornelas; Chiari, Egler
De acordo com os trabalhos publicados ate o momento, o cão esta sendo considerado, com ressalvas, como modelo ideal para o estudo da fase aguda e crônica indeterminada da tripanossomiase cruz jl 2 3 4 5 6 7 14 15 18 19 20 21 24 Os requisitos para um modelo ideal, estabelecidos pelo Comite de Doenca de Chagas do Programa Especial de Treinamento e Pesquisa de Doenças Parasitarias da Organização Mundial de Saude25 podem ser assim discriminados: permitir o isolamento do parasito ao longo do curso da infecção; apresentar reações sorológicas positivas, indicativas da persistência da infecção; apresentar manifestações clinicas da doença de Chagas crônica; desenvolver miocardite, miosite e outras alterações patológicas que caracterizam a doença; induzir a resposta imune contra tecido do hospedeiro. Há mais de oito anos estamos a procura de um modelo que não somente preencha todos os requisitos acima citados mas, principalmente, que desenvolva a cardiopatia grave evolutiva fibrosante com todas alterações clinicas observadas na forma humana. Ate o momento, os resultados que encontramos parecem indicar que alcançamos tal objetivo no modelo cão. A partir destes resultados e dos de outros autores, tentaremos aplicar metodologia moderna no estudo dos vários fatores patogeneticos no pressuposto de que, assim, será possível chegar ao esclarecimento da patogenia e de fisiopatologia das diferentes formas anatomoclinicas da doença. Dentre os numerosos fatores patogeneticos ate agora aventados, a fibrose nos parece o mais importante na determinação da insuficiência cardíaca congestiva (ICC) e da aperistalse. Não existe qualquer outra cardiopatia e/ou mega com aspecto tão peculiar. No miocárdio bem como nos megas, a fibrose (fibrilopoese) e focal e difusa ao mesmo tempo23. O presente trabalho tem a finalidade de documentar a fase crônica da doença de Chagas em cães que recebem inóculos diversos das cepas Colombiana13 e Berenice-7817 de T. cruzi, destacando aqueles animais que desenvolveram a cardiopatia fibrosante, com sinais e sintomas clínicos de ICC.
Hemocultures for the parasitological diagnosis of human chronic Chagas' disease.
(1989) Chiari, Egler; Dias, João Carlos Pinto; Lana, Marta de; Chiari, Cléa de Andrade
With the purpose of standardization of an hemoculture technique presenting a higher positive rate in the parasitological diagnosis of chronic Chagas’ disease in patients with reactive serology (IFT, HA, CFT) the following schedule was used. Thirty ml of venous blood was collected with heparin and the plasma was separated by centrifugation (2.000 rpm/30'). The packed cells were washed with LIT medium or PBS which was then removed by centrifugation (2.000 rpm/15’). This material was sampled in 6 screw-tubes 18x200 with 6 ml of LIT medium and incubated at 28°C. These incubated cultures at 28°C were examined after 15, 30, 45 and 60 days. When the hemoculture was not immediately processed after blood collection, the plasma was removed and the sediment enriched with LIT medium and preserved at 4°C. The Xenodiagnosis was performed according to Schenones method used here as a reference technique. Among the various groups of patients examined by both techniques the best results obtained were: 55.08% ofpositivity for hemocultures against 27.5% forxenodiagnosis (X^ = 4.54, p = 0.05), with a tubepositivity of 26.6%. Recommendation for screening trials of drug assays is the repetition of method on a same patient 2 or more times in different occasions, as used in xenodiagnosis.
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, Wilson
Foi 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.
Experimental Chagas' disease in dogs.
(1992) Lana, Marta de; Chiari, Egler; Tafuri, Washington Luiz
Cardiac plexus of dogs experimentally infected with Trypanosoma cruzi: inflammatory lesions and quantitative studies.
(1995) Caliari, Marcelo Vidigal; Lana, Marta de; Caliari, Estela Regina de Oliveira; Tafuri, Washington Luiz
Qualitative and quantitative aspects of the superficial and profound cardiac plexus of dogs experimentally infected with Be-62 and Be-78 strains of Trypanosoma cruzi were studied. Animals were autopsied in the acute phase o f infection. The inflammatory process, lesions and number of parasites were more intense and frequent in animals infected with the Be-78 strain than in those infected with Be-62. Despite this, no statistically significant differences could be found between the number of neuron bodies in the ganglia of infected and control dogs.
Estudo quantitativo e qualitativo dos plexos de Auerbach e Neissner do esôfago de cães inoculados com o Trypanosoma cruzi.
(1996) Caliari, Estela Regina de Oliveira; Caliari, Marcelo Vidigal; Lana, Marta de; Tafuri, Washington Luiz
Andrade caracterizou bem a fase aguda e a forma indeterminada da cardiopatia chagásica no cão1. Lana inoculando a cepa Be78 em cães caracterizou muito bem a cardiopatia chagásica crônica fibrosame, com quadro clínico e eletrocardiográfico muito semelhante a forma cardíaca humana". Pelo que sabemos, até o momento, não se documentou claramente a forma digestiva (megaesôfago e megacólon) experimental. Também não se tem notícias de estudos sistematizados dos neurônios dos plexos de Auerbach e Meissner do esôfago na tripanosomía s e cruzi experimental. Por estas razões realizamos o presente trabalho , no pressuposto de encontrar prováveis lesões neuronais do esôfago na infecção chagásica experimental canina.
Role of immune complexes from pacients with different clinical forms of Schistosomiasis in the modulation of in vitro granuloma reaction.
(1997) Rezende, Simone Aparecida; Lambertucci, José Roberto; Goes, Alfredo Miranda de
Schistosomiasis is a disease whose pathology is strongly related to the granulomatous reaction formed around parasite eggs trapped in host tissues. Studies have shown that the chronic intestinal form (INT) of this infection is associated with a variety of immunoregulatory mechanisms which lead to a diminished granulomatous reaction. Using an in vitro model of granuloma reaction, we show that immune complexes (IC) isolated from sera of INT patients are able to reduce granulomatous reaction developed by peripheral blood mononuclear cells (PBMC) from acute (AC), INT and hepatosplenic (HE) patients to soluble egg antigen (SEA)-conjugated polyacrylamide beads (PB-SEA). This inhibitory activity is also observed in cell proliferation assay of PBMC from INT and HE patients stimulated with SEA and adult worm antigen (SWAP). Furthermore, IC isolated from sera of patients with different clinical forms of the disease are also able to suppress INT patients PBMC reactivity. Therefore, our results show that circulating IC present in sera of patients with different clinical forms of schistosomiasis may downregulate PBMC reactivity to parasite antigens resulting in a diminished granuloma reaction to parasite eggs.
Down modulation of MHC surface molecules on B cells by suppressive immune complexes obtained from chronic intestinal schistosomiasis patients.
(1998) Rezende, Simone Aparecida; Gollob, Kenneth John; Oliveira, Rodrigo Corrêa de; Goes, Alfredo Miranda de
Granulomatous inflammation around parasite eggs is the prominent lesion in human schistosomiasis. Studies have suggested the involvement of a series of suppressive mechanisms in the control of this reaction, such as macrophages, cytokines, idiotipic interactions and immune complexes (IC). The studies examine the role of IC obtained from chronic intestinal schistosomiasis patients (ISP) in the reactivity of peripheral blood mononuclear cells (PBMC). The results have shown that these immune complexes are able to suppress cell reactivity by inducing an increase in the production of soluble mediators such as prostaglandins and IL-10. To gain a better understanding of how this suppression occurs the present study examines the phenotypic pattern of PBMC after immune complex treatment in cell proliferation assays. These data show that cultures including immune complex present a higher percentage of B lymphocytes in which a lower expression of a MHC-class II gene product, HLA-DR was detected. This altered expression of the HLA-DR molecule on B lymphocytes after IC treatment suggests a novel mechanism for the suppression observed, that is, IC might decrease the antigen-presenting function of B lymphocytes.
Trypanosoma cruzi : compared vectorial transmissibility of three major clonal genotypes by Triatoma infestans.
(1998) Lana, Marta de; Pinto, Artur da Silveira; Barnabé, Christian; Quesney, Virginie; Noel, Sébastien; Tibayrenc, Michel
Nitric oxide-mediated immune complex-induced prostaglandin E2 production by peripheral blood mononuclear cells of humans infected with Schistosoma mansoni.
(1999) Neves, Simone M. F.; Rezende, Simone Aparecida; Goes, Alfredo Miranda de
Granuloma reaction around Schistosoma mansoni eggs is the prominent lesion in human schistosomiasis. Studies have suggested the involvement of a series of suppressive mechanisms in the control of this reaction. Using an in vitro model of granuloma formation, we have shown that immune complexes (IC) isolated from sera of chronic intestinal schistosomiasis patients were able to reduce granulomatous reaction developed against soluble egg antigen-conjugated polyacrylamide beads. In this system, the role of the Larginine– nitric oxide (NO) pathway in the formation of prostaglandin E2 (PGE2) by human peripheral blood mononuclear cells (PBMC) of patients infected with schistosomiasis was investigated using IC. Preincubation of PBMC with IC produced a significant increase of both nitrite and PGE2 levels in the cell supernatant. This effect was inhibited by coincubation of cells with Nv-nitro-L-arginine methyl ester (L-NAME), a NO synthase inhibitor, showing that the release of PGE2 subsequent to IC stimulation was driven by NO. The inhibitory effect of L NAME on PGE2 release by ICtreated PBMC was reversed by sodium nitroprusside, a known NO donor. Our results indicate that NO could be an important second signal for the stimulation of PGE2 production induced by IC in PBMC from human schistosomiasis patients.
Trypanosoma cruzi : infectivity of clonal genotype infections in acute and chronic phases in mice.
(2000) Lana, Marta de; Pinto, Artur da Silveira; Bastrenta, Brigitte; Barnabé, Christian; Noel, Sébastien; Tibayrenc, Michel
Experimental Trypanosoma cruzi biclonal infection in Triatoma infestans : detection of distinct clonal genotypes using kinetoplast DNA probes.
(2000) Pinto, Artur da Silveira; Lana, Marta de; Britto, Constança; Bastrenta, Brigitte; Tibayrenc, Michel
Monitored biclonal densities of parasites were offered to third-stage larvae of Triatoma infestans via an arti®cial feeding device and 30 days later, the gut contents of the insects were processed for microscopic examination and polymerase chain reaction (PCR) detection of Trypanosoma cruzi kinetoplast DNA [kDNA]). A total of 15 mixtures involving nine different stocks attributed to the 19/20, 32 and 39 major clonal genotypes of Trypanosoma cruzi were used. The presence of each T. cruzi clonal genotype after completion of the cycle through the insects was investigated by hybridising the PCR ampli®cation products with genotype-speci®c minicircle kDNA probes. Sixty-®ve out of 90 examined insects (72.2%) were positive for parasites by microscopic examination and 85 (94.4%) were positive by PCR. The results show that almost half of the biclonal infections are not detectable after completion of the cycle, and that there are important differences in detection of such biclonal infections according to the clonal genotypes considered. Moreover, elimination of a clonal genotype by another is a frequent, but not constant, pattern in biclonal infections of T. infestans. The use of PCR and kDNA probes makes it possible to avoid the culture phase, which makes detection of mixed infections much easier in epidemiological surveys. Moreover, the fact that T. infestansdoes not transmit different T. cruzi clonal genotypes with the same ef®ciency has strong implications for the reliability of xenogiagnosis. q 2000 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.
Vibrio mimicus from Vibrio cholerae by multilocus enzyme electrophoresis.
(2001) Vieira, Verônica V.; Teixeira, Luiz Fernando de Medeiros; Vicente, Ana Carolina Paulo; Momen, Hooman; Salles, Carlos André
In this study, we demonstrated that analyzed strains of Vibrio mimicus and Vibrio cholerae could be separated in two groups by using multilocus enzyme electrophoresis (MEE) data from 14 loci. We also showed that the combination of four enzymatic loci enables us to differentiate these two species. Our results showed that the ribosomal intergenic spacer regions PCR-mediated identification system failed, in some cases, to differentiate between V. mimicus and V. cholerae. On the other hand, MEE proved to be a powerful molecular tool for the discrimination of these two species even when atypical strains were analyzed.
Kinetic characterization and inhibition of the rat MAB elastase-2, an angiotensin I-converting serine protease.
(2002) Santos, Carlos F.; Paula, Carmem Aparecida de; Salgado, Maria Cristina de Oliveira; Oliveira, Eduardo Brandt de
An elastase-2 has been recently described as the major angiotensin (Ang) II-forming enzyme of the rat mesenteric arterial bed (MAB) perfusate. Here, we have investigated the interaction of affinity-purified rat MAB elastase-2 with some substrates and inhibitors of both pancreatic elastases-2 and Ang II-forming chymases. The Ang II precursor [Pro11-D-Ala12]-Ang I was converted into Ang II by the rat MAB elastase-2 with a catalytic efficiency of 8.6 min–1·mM–1, and the chromogenic substrates N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide and N-succinyl-Ala-Ala-Pro- Phe-p-nitroanilide were hydrolyzed by the enzyme with catalytic efficiencies of 10.6 min–1·mM–1 and 7.6 min–1·mM–1, respectively. The non-cleavable peptide inhibitor CH-5450 inhibited the rat MAB elastase-2 activities toward the substrates Ang I (IC50 = 49 mM) and N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide (IC50 = 4.8 mM), whereas N-acetyl-Ala- Ala-Pro-Leu-chloromethylketone, an effective active site-directed inhibitor of pancreatic elastase-2, efficiently blocked the Ang II-generating activity of the rat MAB enzyme (IC50 = 4.5 mM). Altogether, the data presented here confirm and extend the enzymological similarities between pancreatic elastase-2 and its rat MAB counterpart. Moreover, the thus far unrealized interaction of elastase-2 with [Pro11-D-Ala12]-Ang I and CH-5450, both regarded as selective for chymases, suggests that evidence for the in vivo formation of Ang II by chymases may have been overestimated in previous investigations of Ang II-forming pathways.
Follow-up of experimental chronic Chagas’ disease in dogs : use of polymerase chain reaction (PCR) compared with parasitological and serological methods.
(2002) Araújo, Flávio Marcos Gomes de; Bahia, Maria Terezinha; Magalhães, Neuza Maria de; Martins Filho, Olindo Assis; Veloso, Vanja Maria; Carneiro, Cláudia Martins; Tafuri, Washington Luiz; Lana, Marta de
In this study, the polymerase chain reaction (PCR) was compared with parasitological and serological methods to detect the infection in dogs, 5–12 years after experimental infection with Trypanosoma cruzi. The ability of parasitological methods to identify a positive animal was 22 and 11% by hemoculture and xenodiagnosis/xenoculture, respectively. On the other hand, the serological tests, including conventional serology and anti-live trypomastigote antibodies (ALTA) were positive in all infected dogs. Despite its low sensitivity, if considering only one reaction, the PCR analysis showed 100% of positivity, demonstrating the presence of parasite kDNA in all infected dogs. To identify a positive dog required at least two blood samples and up to nine repeated reactions using the same sample. Serial blood sample collection, ranging from 1 to 9, revealed that the percentage of dogs with positive PCR ranged from 67 to 100%. These findings suggested that, although the PCR is useful to detect the parasite in infected hosts, it should not be used isolated for the diagnosis of Chagas’ disease and warn for the necessity of serial blood collection and re-tests. Moreover, these data validate once more the dog as a model for Chagas’ disease since they demonstrate the permanence of infection by PCR, parasitological and serological methods, reaching relevant requisites for an ideal model to study this disease.
Impact of Trypanosoma cruzi clonal evolution on its biological properties in mice.
(2002) Toledo, Max Jean de Ornelas; Lana, Marta de; Carneiro, Cláudia Martins; Bahia, Maria Terezinha; Coelho, George Luiz Lins Machado; Veloso, Vanja Maria; Barnabé, Christian; Tibayrenc, Michel
Twenty Trypanosoma cruzi stocks attributed to the 19, 20, 39, and 32 clonal genotypes were comparatively studied in BALB/c mice during the acute and chronic phases of the infection to test the working hypothesis that T. cruzi clonal structure has a major impact on its biological properties. Fourteen parameters were assayed: (1) infectivity; (2) prepatent period; (3) patent period; (4) maximum of parasitemia; (5) day of maximum of parasitemia; (6) parasitemia; (7) mortality, (8) percentage of positive hemoculture, (9) tissue parasitism; (10) inflammatory process during the acute phase of the infection; (11) mortality, (12) percentage of positive hemoculture; (13) tissue parasitism; and (14) inflammatory process during the chronic phase of the infection. Statistical comparison showed that the results are overall consistent with the working hypothesis that biological differences are proportional to the evolutionary divergence among the genotypes. Thus, closely related genotypes (19 vs 20 and 32 vs 39) show in general fewer differences than distantly related groups (19 or 20 vs 32 or 39) except for the comparison between 19 and 32. The working hypothesis is even more strongly supported by the result of the nonparametric Mantel test, which showed a highly significant correlation (P ¼ 2:3 _ 10_3) between biological differences and genetic distances among all pairs of stocks. These data taken together emphasize that it is crucial to take into account the phylogenetic diversity of T. cruzi natural clones in all applied studies dealing with diagnosis, drug and vaccine design, epidemiological surveys, and clinical diversity of Chagas’ disease.
A formação do profissional farmacêutico e o exercício da cidadania na UFOP - Universidade Federal de Ouro Preto.
(2002) Gaede Carrillo, Maria Ruth Gonçalves; Bortolini, Neide das Graças de Souza
Effective immunotherapy against canine visceral leishmaniasis with the FML-vaccine.
(2004) Borja Cabrera, Gulnara Patricia; Mendes, Amanda Cruz; Souza, Edilma Paraguai de; Okada, Lilian Y. Hashimoto; Trivellato, Fernando Antonio de Assis; Kawasaki, Jarbas Kiyoshi Alves; Costa, Andreia Cerqueira; Reis, Alexandre Barbosa; Genaro, Odair; Batista, Leopoldina Maria Melo; Palatnik, Marcos; Souza, Clarisa Beatriz Palatnik de
The potential effect of the fucose mannose ligand (FML)-vaccine on immunotherapy of canine visceral leishmaniasis was assayed on five mongrel dogs experimentally infected withLeishmania donovani and on 21 Leishmania chagasi naturally infected dogs when seropositive to FML but completely asymptomatic. The clinical signs of the experimentally infected, symptomatic dogs only disappeared after the complete vaccination. Protection was obtained in 3/5 animals that remained asymptomatic, IDR positive and parasite free, 1 year after infection. Furthermore, the asymptomatic, FML-vaccine treated dogs showed stable anti-FML IgG1 levels, increasing IgG2 levels and 79–95% of positive DTH response, during the whole experiment. Twenty-two months after complete vaccination, no obits due to visceral leishmaniasis were recorded and 90% of these dogs were still asymptomatic, healthy and parasite free. On the other hand, 37% (17/46 dogs) kala-azar obits were recorded in a control group that received no treatment during the same period, and that was FML-seropositive and asymtpomatic at the beginning of the assay. Our results indicate that the FML-vaccine was effective in the immunotherapy against visceral leishmaniasis of asymptomatic infected dogs. Normal proportions of CD4 and CD21 lymphocytes were detected in PBMC by FACS analysis, in dogs submitted to immunotherapy, suggesting their non-infectious condition. All animals showed as well significantly increased percents of CD8 lymphocytes as expected for Quillajasaponin (QuilA) vaccine treatments.
Leishmania braziliensis : partial control of experimental infection by Interleukin-12 p40 deficient mice.
(2004) Souza Neto, Sebastião Martins de; Carneiro, Cláudia Martins; Vieira, Leda Quercia; Afonso, Luís Carlos Crocco
Resistance to infection by Leishmania major has been associated with the development of a Th1 type response that is dependent on the presence of interleukin 12 (IL-12). In this work the involvement of this cytokine in the response to infection by L. braziliensis, a less virulent species in the mouse model, was evaluated. Our results show that while interferon (IFN-γ) deficient (-/-) mice inoculated L. braziliensis develop severe uncontrolled lesions, chronic lesions that remained under control up to 12 weeks of infection were observed in IL-12p40 -/- mice. IL 12p40 -/- mice had fewer parasites in their lesions than IFN-γ-/- mice. Lymph node cells from IL-12p40 -/- were capable of producing low but consistent levels of IFN-γ suggestive of its involvement in parasite control. Furthermore, as opposed to previous reports on L. major-infected animals, no switch to a Th2 response was observed in IL- 12p40 -/- infected with L. braziliensis.
Evaluation of enzyme-linked immunosorbent assay using crude Leishmania and recombinant antigens as a diagnostic marker for canine visceral leishmaniasis.
(2005) Rosário, Eliza Yoshie do; Genaro, Odair; Silva, João Carlos França da; Costa, Roberto Teodoro da; Mayrink, Wilson; Reis, Alexandre Barbosa; Carneiro, Mariângela
The performances of ELISA assays with different antigen preparations, such as Leishmania amazonensis or L. chagasi lysates and the recombinant antigens rK-39 and rK-26, were compared using sera or eluates from dried blood collected on filter paper to detect anti-Leishmania antibodies in dogs from a visceral leishmaniasis-endemic area in Brazil. Of 115 IFAT-reactive dogs at 1:40 titre, 106 (92.2%) were positive in parasitological exams (skin and/or spleen). These animals were compared to healthy animals (n = 25), negative for IFAT at a titre of 1:40 and parasitological exams. The sensitivities of crude and recombinant antigens were similar and remarkably high for both sera and eluates (97-100%). Specificity was higher than 96% for sera and eluates for different antigens, except for L. chagasi antigen using eluates (88%). Concordance values among the tests were higher either for sera or eluates (J = 0.95-1.00). High concordances were observed between sera and eluates tested with different antigens (kappa = 0.93-0.97). Crude and recombinant antigens identified different clinical phases of canine leishmaniasis. These results show that eluates could be used in canine surveys to identify L. chagasi infection. Recombinant antigens added little when compared to crude antigen in identifying positive dogs. Cross-reactivity with other diseases whose distribution often overlaps VL-endemic areas is a limitation of crude antigen use however.

Browse

Browsing DEACL - Departamento de Análises Clínicas by Issue Date

Results Per Page

Sort Options