Prevalence of Calodium hepaticum (SYN. Capillaria hepatica) in Rattus norvegicus in the urban area of Rio de Janeiro, Brazil.

The nematode Calodium hepaticum (syn. Capillaria hepatica) is a zoonotic helminth found mainly infecting rats. It was studied the prevalence of C. hepaticum infection in Rattus norvegicus in an urban area of Rio de Janeiro (Brazil), with low urban planning and sanitation. The presence of C. hepaticum was identified through visible yellowish-white lesions in liver tissue and histological analyses. The total prevalence of infection was 45%, with no significant differences between sex and age. The presence of infected rodents near the peridomestic area poses substantial risk to human health.

PREVALENCE OF Calodium hepaticum (SYN. Capillaria hepatica) IN Rattus norvegicus IN THE URBAN AREA OF RIO DE JANEIRO, BRAZIL / Prevalência de Calodium hepaticum (sin. Capillaria hepatica) em Rattus norvegicus em área urbana do Rio de Janeiro, Brasil

The nematode Calodium hepaticum (syn. Capillaria hepatica) is a zoonotic helminth found mainly infecting rats. It was studied the prevalence of C. hepaticum infection in Rattus norvegicus in an urban area of Rio de Janeiro (Brazil), with low urban planning and sanitation. The presence of C. hepaticum was identified through visible yellowish-white lesions in liver tissue and histological analyses. The total prevalence of infection was 45%, with no significant differences between sex and age. The presence of infected rodents near the peridomestic area poses substantial risk to human health.

O nematóide Calodium hepaticum (sin. Capillaria hepatica) é um helminto zoonótico encontrado infectando principalmente ratos. A prevalência da infecção de C. hepaticum em Rattus norvegicus foi investigada em área urbana do Rio de Janeiro (Brasil) com baixo planejamento e saneamento. A presença de C. hepaticum foi identificada através da presença de lesões macroscópicas caracterizadas por manchas extensas de coloração branco-amarelada difusa por toda superfície do tecido do fígado e através de análise histológica. A prevalência total da infecção foi de 45% sem diferença significativa entre o sexo e idade. A presença de roedores infectados próximos do peridomicílio representa um risco substancial para a saúde humana.

Expression and arrangement of extracellular matrix proteins in the lungs of mice infected with Paracoccidioides brasiliensis conidia.

Extracellular matrix (ECM) proteins are important modulators of migration, differentiation and proliferation for the various cell types present in the lungs; they influence the immune response as well as participate in the adherence of several fungi including Paracoccidioides brasiliensis. The expression, deposition and arrangement of ECM proteins such as laminin, fibronectin, fibrinogen, collagen and proteoglycans in the lungs of mice infected with P. brasiliensis conidia has been evaluated in this study, together with the elastic fibre system. Lungs of BALB/c mice infected with P. brasiliensis conidia were analysed for the different ECM proteins by histological and immunohistochemical procedures at different times of infection. In addition, laser scanning confocal microscopy and scanning electron microscopy were used. During the early periods, the lungs of infected animals showed an inflammatory infiltrate composed mainly of polymorphonuclear neutrophils (PMNs) and macrophages, while during the later periods, mice presented a chronic inflammatory response with granuloma formation. Re-arrangement and increased expression of all ECM proteins tested were observed throughout all studied periods, especially during the occurrence of inflammatory infiltration and formation of the granuloma. The elastic fibre system showed an elastolysis process in all experiments. In conclusion, this study provides new details of pulmonary ECM distribution during the course of paracoccidioidomycosis.

Expression of adhesion molecules in lungs of mice infected with Paracoccidioides brasiliensis conidia.

In infected tissues, leukocyte recruitment is mediated by interactions between adhesion molecules, expressed on activated vascular endothelial cells, and ligands present on circulating cells. We evaluated the inflammatory response and the expression of cellular adhesion molecules (ICAM-1, VCAM-1, CD18, LFA-1 and Mac-1) in lungs of BALB/c mice infected with Paracoccidioides brasiliensis conidia. When compared with uninfected animals, infected mice had a significant increase in the inflammatory response during the first 4 days, peaking 2-3 days post-challenge, 40.3% vs. 0.0% and 41.8% vs. 0.7%, respectively. This inflammatory infiltrate was composed mainly of neutrophils and macrophages with a few eosinophils and lymphocytes. An increase in the intensity of immunofluorescence (IF) for ICAM-1 was also observed during days 1-4. ICAM-1 was present in bronchiolar epithelium, type II pneumocytes, and macrophages, as well as on vascular endothelium. The control animals presented ICAM-1 constitutively. In infected mice, VCAM-1 was only observed on vascular endothelium during the first 2 days, with some macrophages expressing this molecule throughout the study periods. CD18 and Mac-1 but not LFA-1 were expressed with a high intensity on neutrophils and macrophages present in the inflammatory infiltrate. In addition, we observed a significant decrease in Colony forming units (CFUs) after the first 2 days post-challenge. These findings suggest that during these early stages, up-regulation of ICAM-1, VCAM-1, CD18 and Mac-1 expression occurs, participating in the inflammatory process and as such, in the pathogenesis of paracoccidioidomycosis (PCM).

Distinct patterns of microvasculature in the cutaneous lesions of leprosy

This work is an investigation on the microvasculature of the cutaneous infiltrates of leprosy with the immunohistochemical staining of endothelial cells in cutaneous biopsies. Anti-Factor VIII-related antigen antibody (anti-FVIII-ra) and Ulex Europaeus-1 lectin (UEA-1) binding were utilized as endothelial cell markers. Thirty-nine patients grouped according to the Ridley-Jopling classification (14 borderline tuberculoid, 18 borderline lepromatous, 6 lepromatous, and 1 indeterminate leprosy) were selected for this study. Two microvascular architectural patterns could be clearly distinguished: lepromatous lesions presented a dense and tortuous mesh of microvessels among the Mycobacterium leprae-glutted macrophages; whereas the microvessels in the tuberculoid lesions were restricted to the periphery of the granulomas and were not seen among the central epithelioid cells. We were able to distinguish three basic morphological kinds of infiltrate distribution related to the microvessels: micronodules, cords and macronodules. Intensifications of the FVIII-ra immunoreactivity and UEA-1 binding capacity were observed in the endothelial cells of microvessels involved by the inflammatory infiltrate. A distinct cytokine expression profile at the leprosy poles and the role of mast cells in angiogenesis were speculated as factors contributing to these distinct patterns. Growth of the lesion and systemic dissemination of M. leprae in the bipolar spectrum of leprosy may hypothetically be influenced by the vascular-infiltrate relationship. The detection of angiogenesis in the cutaneous lesions of leprosy may bring about alternate and/or additional strategies for leprosy treatment.