ABSTRACT
Renal involvement in visceral leishmaniasis (VL) is very frequent. The renal lesions of humans and dogs are similar but their pathogenesis has not been clearly elucidated. There is growing evidence that the cellular immune response is involved in the pathogenesis of immunologically mediated glomerulonephritis. Since T cells could participate in the pathogenesis of nephropathy, in the present study we investigated the possible involvement of CD4+ and CD8+ T cells in the nephropathy of canine VL. Six dogs naturally infected with Leishmania (Leishmania) chagasi from the endemic area in the Northeast of Brazil, the town of Teresina in the State of Piauí, were studied. An expressive inflammatory infiltrate of CD4+ T cells both in glomeruli and in interstitium was present in 4 animals and absent in 2. CD8+ T cells were detected only in one animal. CD4+ T cells alone were observed in 3 animals; when CD8+ T cells were present CD4+ T cells were also present. CD4+ T cells were observed in cases of focal segmental glomerulosclerosis, diffuse membranoproliferative glomerulonephritis, diffuse mesangial proliferative glomerulonephritis and crescentic glomerulonephritis. CD8+ T cells were present only in a case of crescentic glomerulonephritis. Leishmania antigen was detected in glomeruli and in interstitial inflammatory infiltrate in 4 animals and immunoglobulins were observed in 4 dogs. In this study we observed that T cells, in addition to immunoglobulins, are present in the renal lesion of canine VL. Further studies are in progress addressing the immunopathogenic mechanisms involving the participation of immunoglobulins and T cells in canine VL nephropathy
Subject(s)
Animals , Dogs , CD4-Positive T-Lymphocytes , CD8-Positive T-Lymphocytes , Dog Diseases/parasitology , Glomerulonephritis/veterinary , Leishmaniasis, Visceral/veterinary , Antigens, Protozoan/analysis , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Dog Diseases/immunology , Dog Diseases/pathology , Kidney/immunology , Kidney/pathology , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/pathology , Leishmania/immunologyABSTRACT
The in utero exposure of hamsters to low doses of diazepam results in impaired host defense against Mycobacterium bovis during adulthood. Delayed developmental immunotoxicity, however, represents a specific situation that might not be general. The present experiment was undertaken to investigate the effects of diazepam on hamster resistance to M. bovis using adult animals. The effects of diazepam treatment on serum cortisol levels were also studied. Adult hamsters (N = 10 for each group) were treated with diazepam (E1 = 1.0, E2 = 2.0 or E3 = 3.0 mg kg-1 day-1 subcutaneously) or with control solution (C) for 30 days. Seven days after the beginning of the treatment, the animals received identical inoculum concentrations of M. bovis. Hamsters treated with the higher (2.0 and 3.0 mg kg-1 day-1) doses of diazepam exhibited: 1) increased granuloma areas in the liver (C = 1.81 + or - 1.39, E2 = 10.29 + or - 4.64 and E3 = 15.80 + or - 4.82) and lung (C = 0.54 + or - 0.55, E2 = 6.28 + or - 3.85 and E3 = 6.31 + + or - 3.56) and 2) increased scores of M. bovis colony-forming units isolated from liver (C = 2.0, E2 = 3.0 and E3 = 3.5), lung (C = 1.0, E2 = 3.0 and E3 = 3.5) and spleen (C = 1.0, E2 = 2.5 and E3 = 4.0). These effects were dose dependent, and were not detected or were less severe in animals treated with the lowest (1.0 mg/kg) dose of diazepam as well as in those of the control group. Furthermore, diazepam treatment (3.0 mg kg-1 day-1 for 30 days) increased (E3 = 71.32 + or - 2.99; N = 10) the serum levels of cortisol compared to control hamsters (C = 22.61 + or - 2.75; N = 10). The present data, that demonstrate an impaired defense against M. bovis in adult hamsters treated with diazepam, were tentatively explained on the basis of a direct and/or indirect action of diazepam on the cytokine network. The effects may be related to stimulation of peripheral benzodiazepine receptor binding sites (PBR) by macrophages and/or lymphocytes, or they may be mediated by PBR stimulation of the adrenals
Subject(s)
Animals , Male , Anti-Anxiety Agents/toxicity , Cricetinae/microbiology , Diazepam/toxicity , Drug Resistance, Microbial , Mycobacterium bovis/drug effects , Tuberculosis/drug therapy , Analysis of Variance , Anti-Anxiety Agents/therapeutic use , Diazepam/therapeutic use , Macrophages/drug effectsABSTRACT
Os produtos de origem animal desempenham importante papel na alimentaçäo humana devido ao seu valor protéico, porém deve-se evitar que sirvam de vias de transmissäo de doenças aos seus consumidores. A interaçäo dinâmica entre o serviço de inspeçäo de carnes e as técnicas laboratoriais diagnósticas deve ser mantida na profilaxia das doenças veiculadas por alimentos. Relata um caso de contaminaçäo bacteriana de tecido muscular de bovino destinado ao consumo humano. Macroscopicamente observaram-se lesöes granulomatosas semelhantes àquelas associadas à tuberculose. Colheu-se 2,0g do material e, utilizando-se a técnica de descontaminaçäo de Petroff (OPS 1993), tentou-se o isolamento de Mycobacterium ssp, a partir dos meios de Lowenstein-Jensen e de Stonebrink-Lesslie a 37§C. Outro fragmento foi colhido e fixado em formol a 10 por cento para exame histopatológico. Após sete dias de cultivo observou-se no meio de Lowenstein-Jensen a presença de colônias rugosas com pigmento alaranjado. No exame bacteriológico observou-se micélios que se fragmentavam formando bacilos Gram positivos. No corte histológico, corado em Hematoxilina-Eosina, verificaram-se estruturas granulomatosas. Foi identificado Nocardia asteroides a partir das colônias isoladas. Estes microrganismos säo considerados saprófitas, telúricos capazes de causar infecçöes inicialmente pulmonares, disseminando-se posteriormente para outros órgäos, como: rins, baço, fígado, cérebro e ocasionalmente de desenvolver micetomas. Sem auxílio de profissionais integrados e capacitados para diagnosticar esta patologia, haveria maior risco para o consumidor. Conclui-se, portanto, que a crescente integraçäo entre os profissionais de saúde pública e saúde animal permite o aprimoramento das práticas diagnósticas e de prevençäo das zoonoses.
Subject(s)
Cattle Diseases/transmission , Food Parasitology , Nocardia asteroides/isolation & purificationABSTRACT
Seeds of Crotalaria spectabilis, containing the pyrrolizidine alkaloid (PA) monocrotaline (MCT), were fed to a lactating dairy goat. Milk from this goat was fed to rats for 8 weeks to determine whether MCT or its toxic metabolites are transferred into the goat's milk. Rats from the experimental group showed significantly higher (p<0.05) serum levels of ALT, AST, GGT and LDH and less weight gains (p<0.05) than control rats. The most significant lesions in rats consuming the experimental ration were mild to moderate interstitial pneumonia and a vacuolar degeneration and occasionally necrosis of periportal hepatocytes. The results of this study indicate that the PA and/or its metabolites are eliminated in milk
Subject(s)
Animals , Female , Milk , Poisoning , Pyrrolizidine Alkaloids , SeedsABSTRACT
Em patologia humana, a análise e interpretaçäo das linfadenopatias reacionais baseia-se na caracterizaçäo morfológica das várias regiöes do linfonodo. Em patologia veterinária náo há essa padronizaçäo. No presente estudo, utilizamos as bases da classificaçäo de Dorfmari-Wamke (modificada por Burke), utilizada na área médica humana para avaliarmos uma linfadenite viral experimental em cobaias. Parvovírus canino foi inoculado em coxim plantar de cobaias e a resposta dos linfonodos poplíteos avaliada. No fim de cada período experimental, linfonodos foram excisados, pesados e processados histologicamente em cortes corados pelos métodos de Giemsa, Mallory, Gordon & Sweets e Hematoxilina-Eosina e por meio de imunoistoquímica com anticorpos pan-T e pan-B. Foi observado aumento de peso significante (pSubject(s)
Animals
, Male
, Female
, Lymphadenitis
, Parvovirus, Canine
, Pathology
ABSTRACT
Estudou-se comparativamente, através de métodos histoquímicos, a expressäo dos componentes da matriz extracelular de tumores primitivos e metastáticos em ratos nude, xenotransplantados com células KB. Em ambas as neoplasias observou-se uma variabilidade tanto qualitativa como quantitativa dos componentes matriciais, coexistência de diferentes tipos de fibras, pouca representatividade de fibras elásticas de glicosaminoglicanas ácidas e sulfatadas e de polissacarídeos neutros, além da ausência de membrana basal
Subject(s)
Animals , KB Cells/ultrastructure , Extracellular Matrix/ultrastructure , Neoplasms , RatsABSTRACT
O tumor de Ehrlich cresce na forma sólida quando inoculado no coxim plantar de camundongos, disseminando-se para o linfonodo poplíteo. Este estudo foi realizado com o intuito de caracterizar as células tumorais que cresceram no coxim plantar e as que migraram para o linfonodo poplíteo. O volume nuclear dessas células foi medido com o auxílio de ocular cariométrica. A quantificaçäo do DNA foi feita através de citofotometria em células coradas pelo método de Feulgen. As células tumorais encontradas nos linfonodos poplíteos uma hora após a inoculaçäo no coxim plantar näo apresentaram diferenças estatísticas do tumor ascítico original e das células tumorais do coxim plantar em relaçäo à quantidade de DNA, no mesmo tempo experimental. As células tumorais dos linfonodos poplíteos aos 30 dias após a inoculaçäo mostraram menor volume nuclear e a mesma quantidade de DNA do que as que cresceram no coxim plantar. As células tumorais presentes no coxim plantar 30 dias após a inoculaçäo mostraram uma quantidade maior de DNA do que as colhidas uma hora após a inoculaçäo. Estes resultados sugerem um possível efeito seletivo nas células do tumor de Ehrlich que crescem no coxim plantar, mas näo quando de sua metastatizaçäo para o linfonodo regional