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Background: Paracoccidioidomycosis (PCM) is a severe granulomatous disease. The hallmark of this mycosis is fibrin degradation and granuloma formation as a result of a wound-healing process in the context of excessive inflammation. Therefore, as the content of collagen can be assessed by the methodology described in this manuscript, we propose that the content of hydroxyproline (HYP) be employed as a new and efficient measurement of granulomatous lesions developed. To estimate the level of HYP the major byproduct of the degradation process, we hypothesized that this simple and efficient technique could serve as a marker of disease severity. Methods: Five B10.A female mice were infected with P. brasiliensis and, after 15 days, the omentum was removed, subjected to histopathological analysis or processed (i.e. deproteinized and derivatized), and further analyzed on a reverse phase HPLC using a C-18 column. The omentum of five uninfected controls was also collected and similarly analyzed. Results: Infected mice showed numerous, disseminated paracoccidioidomycotic lesions, as well as marked collagen deposits, as observed in histopathologic analysis, and high levels of HYP. Normal uninfected mice showed no granulomas, little or no deposits of collagen fibers, and very low levels of HYP, as evaluated by HPLC. Our results show that the disease intensity as evaluated number and the morphology of the granulomatous lesions were correlated to the HYP levels using small tissue samples from the omentum, the main target organ of P. brasiliensis. Conclusions: Here we propose an alternative methodology to follow disease evolution and, to some extent, fungal load in experimental P. brasiliensis infection and suggest its usefulness to other diseases with pronounced fibrin degradation.
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BACKGROUND: Granulomatous Lung Diseases (GLD) encompasses a wide range of infectious and non-infectious conditions characterized by chronic inflammatory response. However, different GLD may share similar imaging findings. In this context, the purpose of this study was to outline the etiological profile and their imaging features in patients with GLD who underwent lung biopsy. METHODS: Patients with granulomatous lesions in lung biopsies and previous chest CT performed from 2014 to 2017 at our institution had imaging data reviewed by three blinded radiologists. The imaging features were analyzed according to the Fleischner Society glossary. Categorical data were represented by absolute (n) and relative (%) frequency. The contingency matrices were analyzed by Pearson's Chi-square test. Interreader agreement was assessed by calculating the intraclass correlation coefficient, using kappa (κ) statistic. RESULTS: Thirty-eight of 75 (50.7%) patients were women with a mean age of 59 ± 39 years. Infection was the most common cause of GLD (47/75, 62.7%) and Histoplasma capsulatum (27/75, 36%) was the most prevalent etiology. Nodular pattern was the most common imaging feature in histoplasmosis cases (25/27, 92.6%), whereas it occurred in half of cases (24/48) of GLD of other causes (p < 0.05). Among patients with tuberculosis, the second etiology of GLD in our study population, the most common imaging pattern was centrilobular micronodules (3/7, 42.9%), significantly more frequent than in other causes of GLD (6/68, 8.8%). Interreader agreement in detecting imaging features was almost perfect (κ = 0.88-1.00), except the nodular pattern, which had substantial agreement (κ = 0.73). CONCLUSIONS: In our study population, the main etiologies found in patients with granulomatous disease who underwent lung biopsy were fungal or mycobacterial disease, specially histoplasmosis and tuberculosis, and nodular pattern with focal distribution was the most common imaging finding which was detected with substantial interreader agreement.
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Background: non-tuberculous mycobacteria (NTM) infect humans and animals and have a critical confounding effect on the diagnosis of bovine tuberculosis. The Official Mexican Standard (Norma Oficial Mexicana, NOM-ZOO-031-1995) for food safety regulates Mycobacterium bovis in cattle, but not the NTM species. The study's objective was to isolate and identify the NTM present in condemned bovine lymph nodes in a slaughterhouse, characterize the histological lesions, and correlate bacteriological and microscopic findings with the antemortem tuberculin skin test. Methods: from 528 cattle, one or two pooled samples of lymph nodes from each animal were cultured for Mycobacteria spp. and processed for histopathology. Results: mycobacteria were isolated from 54/528 (10.2%) of the condemned lymph nodes; 25/54 (46.2%) of these isolates were NTM; 4 bacteriological cultures with fungal contamination were discarded. Granulomatous and pyogranulomatous inflammation were present in 6/21 (28.6%) and 7/21 (33.3%) of the NTM-positive lymph nodes, respectively. The species of NTM associated with granulomatous lymphadenitis were M. scrofulaceum, M. triviale, M. terrae, and M. szulgai, while those causing pyogranulomatous lesions were M. szulgai, M. kansasii, M. phlei, and M. scrofulaceum. Conclusions: the NTM infections can cause false-positive results in the tuberculin test because of cross immune reactivity and interference with the postmortem identification of M. bovis in cattle.
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The article describes an atypical case of cat-transmitted ocular sporotrichosis due Sporothrix brasiliensis in a young patient. This report contributes significantly to knowledge of sporotrichosis as an important neglected tropical disease. In addition, this condition is an important public health problem in ascending incidence.