Fonsecaea pedrosoi is a fungal pathogen that produces melanin. The functions of melanin and its possible influence in the protective immunological response during infection by F. pedrosoi are not known. In this work, treatment of F. pedrosoi mycelia with proteases and glycosidases followed by a denaturing agent and hot concentrated acid left a black residue. Scanning electron microscopy demonstrated that this processed melanized residue resembled very closely the intact mycelium in shape and size. Melanin particles were also isolated from culture fluids of conidia or sclerotic forms of F. pedrosoi. Secreted melanins were reactive with sera from infected human patients, suggesting that F. pedrosoi synthesizes melanin in vivo. The antibodies against melanin were purified from patients' sera and analyzed by indirect immunofluorescence. They reacted with sclerotic cells from patients' lesions as well as with sclerotic bodies cultivated in vitro, conidia, mycelia, and digested residues. Treatment of F. pedrosoi with purified antibodies against melanin inhibited fungal growth in vitro. The interaction of F. pedrosoi with phagocytes in the presence of melanin resulted in higher levels of fungal internalization and destruction by host cells, which was accompanied by greater degrees of oxidative burst. Taken together, these results indicate that melanin from F. pedrosoi is an immunologically active fungal structure that activates humoral and cellular responses that could help the control of chromoblastomycosis by host defenses.
Treatment with direct electric current (DC) can inhibit tumor growth in several systems. To evaluate the cellular reactions generated by this treatment, we stimulated mouse mastocytoma P815 cells with DC and examined their viability and ultrastructural characteristics, as well as the effect of DC on surface carbohydrate expression. DC treatment affected cell viability and caused marked alterations in vital structures of P815 cells. Alterations varied depending on the duration of stimulation and polarity of electrode. Anodic and cathodic treatments caused decrease in cell viability, although the latter was more effective in generating cell lysis. DC stimulation also induced changes such as membrane damage, alterations in cell shape and chromatin organization, mitochondrial swelling and condensation, cytoplasmic swelling, and matrix rarefaction. Stimulation of P815 cells without contact with electrodes produced no alterations, suggesting that this contact might be essential for the occurrence of the cellular modifications. DC treatment also altered the membrane distribution of anionic sites of P815 cells, as well as the surface carbohydrate exposition, involving a diminished binding of Concanavalin A to the cell surface after cathodic stimulation, and an increased binding of sialic acid- and fucose-specific lectins after anodic treatment. In this work we describe important cellular targets for the action of DC, which may contribute to the understanding of the mechanisms by which DC supresses several kinds of tumors.
Treatment with direct electric current (DC) influences the growth of several cancer cells. In this work, we evaluated the effects of DC treatment on the human leukemic cell line HL60. Human cells were separately treated in the presence of the cathode or the anode or without contact with the electrodes. In all systems, DC-treated cells presented an impaired ability to proliferate. Growth inhibition was dependent on the generation of soluble products of electrolysis. Cathodic treatment of HL60 cells predominantly induced lysis, whereas treatment without contact with electrodes did not induce alterations in cell viability. In contrast, cell stimulation by the anode resulted in irreversible membrane damage, as demonstrated by trypan blue and 7-aminoactinomycin staining. Analysis of these cells by transmission electron microscopy indicated that necrosis is a major mechanism inducing cell death. In addition, apoptotic-like cells were observed under light microscopy after anodic treatment. Accordingly, DNA from anodic-treated cells presented a typical pattern of apoptosis. Apoptotic cell death was only generated after the treatment of HL60 cells in conditions in which the generation of chloride-derived compounds was favored. These results indicate that the nature of the products from cathodic or anodic reactions differently influences the mechanisms of cell death induced by DC-derived toxic compounds.
Cancer is one of the biggest problems in public health worldwide. Plants have been shown important role in anticancer research. L. (Santalaceae), commonly known as mistletoe, is a semi-parasitic plant that grows on different host trees. In complementary medicine, extracts from European mistletoe ( L.) have been used in the treatment of cancer. The study was conducted to identify chemical composition and antitumor potential of tinctures. Chemical analysis performed by high resolution chromatography equipped with high resolution mass spectrometer identified caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A compounds. Some of these compounds are probably responsible for the reduction of tumoral cellular growth in a dose-dependent manner. It was observed that melanoma murine cells (B16F10) were more sensitive to tinctures than human leukaemic cells (K562), besides non-tumoral cells (MA-104) had a much lower cytotoxicity to them. Apoptotic-like cells were observed under light microscopy and were confirmed by a typical DNA fragmentation pattern. Additionally, flow cytometry results using Annexin-V/FITC permitted to quantify increased expression of early and late apoptotic markers on tumoral cells, confirming augmented Sub G0 population, which was probably associated with a consistent decrease in G1, and an increase in S or G2/M populations. Results indicate the chemical composition of tinctures influences the mechanisms of tumoral cell death, suggesting a potential use in cancer pharmacotherapy research.
Resumo Legitimadas pela Organização Mundial da Saúde, as Práticas Integrativas e Complementares apresentam demanda crescente e têm a formação profissional como um dos maiores desafios para o seu avanço no Sistema Único de Saúde. O estudo quantitativo descrito apresenta a oferta de disciplinas e cursos em Práticas Integrativas e Complementares em seis instituições de ensino superior públicas no Estado do Rio de Janeiro, em 2014, identificada em seus respectivos sites e secretarias segundo as variáveis: instituições de ensino superior, subárea de saúde, nível do ensino (graduação e pós-graduação), subtemas das Práticas Integrativas e Complementares (Homeopatia, Acupuntura, Meditação etc.), formato (obrigatório, eletivo ou optativo) e conteúdo (informativo ou formativo). Os resultados mostram uma oferta de 56 unidades de ensino, distribuída em quase todas as subáreas de saúde, com maior concentração em cursos de Medicina, Farmácia e Enfermagem. De perfil predominantemente opcional e informativo, apresenta a Homeopatia, Meditação e Práticas Corporais como temas mais frequentes. A análise desta oferta, apoiada na perspectiva do cuidado integral e referenciada em literatura nacional e internacional, aponta desafios para a ampliação e qualificação do ensino de Práticas Integrativas e Complementares, dentre eles a inserção integrada em cursos de saúde visando a interação e complementaridade entre saberes distintos.
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