Navegando por Assunto "Lacazia loboi"

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Acesso aberto (Open Access)
Imunoexpressão para CD1a em lesões cutâneas na doença de Jorge Lobo
(Universidade Federal do Pará, 2009) UNGER, Deborah Aben-Athar; BRITO, Arival Cardoso de; http://lattes.cnpq.br/0563291980190339
Jorge Lobo’s disease (DJL) is a chronic infection caused by the fungus Lacazia loboi, endemic in South America, especially in the Brazilian Amazon region. The most common clinical presentation is parakeloidal lesion located mainly in the lower limbs in men who practice agricultural activity. The fungus can be identified by both mycological and anatomopathological examination. The main objective of this study was to investigate the possible role of Langerhans' cells (LC) in the pathogenesis of the disease in tissue samples from skin lesions, using immunohistochemical technique. Thirty-three medical records were selected with their respective paraffin blocks of skin biopsies from patients with DJL (group 1) registered in the dermatology service at the Federal University of Para in the period from 1955 to 2005. The control group consisted of 10 paraffin blocks from normal skin (group 2) and 42 blocks from patients with paracoccidioidomycosis (PCM) (Group 3). In the analysis of patient medical records data were collected regarding age, sex, origin, profession, location and clinical type of the lesions. Langerhans cells were identified by immunohistochemistry using anti-CD1a antibody (Serotec). Patients were mostly men (84, 8%), farmers (72. 7%) aged between 46-65 years, with predominance of parakeloidal lesions (81. 8%) in the lower limbs (45. 5%). The number of positive cells was statistically analyzed. The LC were visualized along the epidermis in all biopsies from Jorge Lobo's disease. The morphology and the number of cells, did not differ from normal skin (p> 0. 05), and was increased when compared to the PCM lesions (p <0. 05). Langerhans cells were present in Jorge Lobo’s disease skin lesions similarly to the way they are in normal skin, not suffering any numerical or morphological alterations, unlike what occurred in PCM. These results suggest that in DJL fungi probably present some escape mechanism of the local immune system to evade the antigen presentation by Langerhans’ cells.
Acesso aberto (Open Access)
Imunopatogenia da interação entre acrófagos e/ou células de Langerhans e Lacazia loboi
(Universidade Federal do Pará, 2014-04-24) YAMANO, Suellen Sirleide Pereira; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Lobomycosis is a chronic, granulomatous, fungal infection of the skin and subcutaneous caused by the fungus Lacazia loboi. This mycosis occurs predominantly in Amazon region and affect all populations groups. Histologically, there is a chronic inflammatory reaction characterized by the intense fibroplastia and histiocytosis, abundant number of macrophages, multinucleated giant cells and presence of large numbers of yeast. Macrophages are phagocytic cells that participate in the recognition and response to pathogens through phagocytosis, antigen presentation to T lymphocytes and cytokine production. Langerhans cells (LC) are a group of dendritic cells (DC) derived from bone marrow, which are located mainly in the suprabasal layer of the epidermis. Studies on hostfungal interaction in Jorge Lobo's disease are scarce. Therefore, this study constitutes an important step towards a better understanding of L. loboi biology and pathogenesis, enabling in vitro culture of this organism endemic in Amazon region and study of their antigenic properties, as well as new therapeutic approaches. The objective of this study was to analyze the in vitro interaction between non-activated peritoneal macrophages and/or Langerhans cells isolated from BALB/c mice and L. loboi, calculating infection, phagocytosis and cellular fusion rates; also measuring the production of TNF, IL-4, IL-6, IL-10 and IL-12. Results showed that L. loboi is phagocytosed by macrophages but not by LC. Phagocytosis and infection rates in the interaction between macrophages and L. loboi was similar to interaction between macrophages, Langerhans cells and L. loboi at all times analyzed. The mean number of yeast cell per macrophage was almost equal among interactions and over time, with mean variation from 1.2 to 1.6 yeast/macrophages. No giant cells formation in coculture studied. No significant difference occurred in IL-4, Il-2 and IL-10 production between interactions studied. TNF levels decrease in interaction between macrophages and L. loboi while adding LC induces increased production of TNF-α, especially after 48 hours. LC negatively modulate IL-6 production by macrophage and L. loboi also inhibits this production by macrophages alone or cocultured with LC. L. loboi stimulated significantly IL-12 production by macrophages co-cultured with LC, but not for LC alone or macrophages.
Acesso aberto (Open Access)
Isolamento e cultivo in vitro do agente etiológico da Doença de Jorge Lobo: morfologia, fisiologia e genoma de Candida loboi sp. nov
(Universidade Federal do Pará, 2015-12-18) COSTA, Patricia Fagundes da; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Jorge Lobo’s disease is a chronic granulomatous infection developing after traumatic implantation of the fungus in the skin. It presents with nodular, verrucous or keloid-like lesions mainly on legs and ears. The highest prevalence is at Amazon Region and it has been considered an emergent disease, presenting new cases on other continents in both, humans and dolphins. Little is known about L. loboi, and the absence of in vitro culture impairs the correct characterization of the fungus. This work had as the main goal to isolate, culture and characterize strains of the etiological agent of Jorge Lobo´s disease, obtained from patients attended at the Dr Marcello Candia Reference Unit in Sanitary Dermatology of the State of Pará, in Marituba, Pará, Brazil. During many years 23 patients were diagnosed and followed by our team. Most of them were male farmers, with age varying from 14 to 80 years-old. After biopsy of the lesion for confirming the diagnosis, the patients initiated treatment and the material was processed with dispase II at liquid medium RPMI, 37º C, 5% CO2 for 1-2 weeks to isolate yeast cells from human tissue. After 2-6 months in the medium, we observed fragmentation of mother cells and the presence of new yeast cells with diameter varying from 1 to 7μm. From that moment, it was possible to grow the strains in different liquid or solid mediums at 37º C or RT, where creamy, whitish cerebriform, sometimes hairy colonies were observed. Cells from those strains were analyzed by different techniques of optical and electron microscopy, biochemistry and genetics, ending with the description of the genome of one patient just after isolation of the fungal cells from the lesional skin, defining the following taxonomic identification: Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes; Saccharomycetales; Debaryomycetaceae; Candida/Lodderomyces clade; Candida; Candida sp. LDI48194. The peculiar clinical presentation associated to unique morphological, physiological and genetic characteristics that do not permit the definition of a known species indicate that the etiological agent of Jorge Lobo’s disease is a new species, for which we propose to use the name Candida loboi.