44 resultados para Cell Extracts

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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This study analyzed the histopathology of rabbit skin, previously immunized with SGE2, SGE4, and SGE6 gland extracts prepared from salivary glands of Rhipicephalus sanguineus female with 2, 4, and 6 days of feeding, at the region of the R. sanguineus female feeding lesion 2, 4, and 6 days after tick attachment. In this work, infestation-naïve New Zealand White rabbits were inoculated either with the extracts (test group (TG)) or with phosphate buffer and complete Freund's adjuvant mixture (control group 2 (CG2)). Each extract-inoculated- (TG and CG2) and non-inoculated (CG1) rabbit was subsequently infested with R. sanguineus. Skin biopsies were collected from the rabbit at the tick feeding lesion at 2, 4, and 6 days of feeding. Results revealed that rabbit immunization with gland extracts induced acquisition of resistance against this species. It should be stated that the SGE4 extract was the most effective in developing an immune-inflammatory response against ectoparasites, being this process characterized by the presence of an early and intense inflammatory cell infiltrate. On the other hand, SGE6 extract caused a later appearance of resistance with less infiltrate occurrence and intense edema at the feeding lesion site. As to the inflammatory process deriving from SGE2 extract inoculation, it was the less intense. It was concluded that immunization with different extracts from R. sanguineus female salivary glands did not change microscope features of the inflammatory process, although an earlier or more intense and later response, which was also dependent on the inoculate extract, was noticed. © 2012 Springer-Verlag Berlin Heidelberg.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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1. The mycelial Pi-repressible acid phosphatase presented p-nitrophenylphosphatase activity with negative cooperativity and Michaelian behavior when synthesized by the wild-type and pho-2A mutant strains of Neurospora crassa, respectively.2. The major acid phosphatase present in cell extracts of the pho-2A mutant of N. crassa grown in low Pi medium is more thermolabile (t1/2 = 4 min at 54-degrees-C, pH 5.4) than that of the wild strain (stable for at least 80 min at 54-degrees-C, pH 5.4).3. The pho-2A mutant of N. crassa secreted a more thermolabile acid phosphatase (t1/2 = 30 min at 50-degrees-C, pH 5.4) than the wild strain (t1/2 of at least 80 min at 50-degrees-C, pH 5.4).4. The pho-2A mutant of N. crassa synthesized a more thermolabile acid phosphatase (t1/2 = 37 min at 54-degrees-C, pH 5.4) than the wild strain in high Pi medium (t1/2 = 14 min al 54-degrees-C, pH 5.4).5. The pleiotropic nature of the pho-2 locus and its possible involvement in the mechanism of phosphatase secretion by N. crassa are proposed.

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Intracellular and extracellular catalases of different species of Candida were investigated using different culture media. All the Candida strains produced intracellular catalase, whose enzymatic activity was detected by non-denaturating polyacrylamide gradient (4-30%) gel electrophoresis. The cell extracts presented a major 230 kDa catalase band and in some strains variants of catalase with different molecular weights were detected. Candida catalase activity was not affected by heating at 50degreesC and incubation with beta-mercaptoethanol, but treatment with sodium dodecyl sulphate inhibited or reduced enzymatic activity. Extracellular enzyme activity was not detected in any of the culture filtrate extracts tested.

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The metalloendopeptidase EP24.15 (EC3.4.24.15) is a neuropeptide-metabolizing enzyme present in neural and endocrine tissues, presumably functioning extracellularly, Because the majority of the EP24.15 activity is identified in the soluble fraction of cellular homogenates, suggesting that the enzyme is primarily an intracellular protein, we addressed the issue of how EP24.15 arrives in the extracellular environment, We utilized a model system of neuroendocrine secretion, the AtT20 cell, According to both enzymatic activity and immunologic assays, EP24.15 was synthesized in and released from AtT20 cells. Under basal conditions and after stimulation by corticotropin-releasing hormone or the calcium ionophore A23187, EP24.15 activity accumulated in the culture medium. This secretion was not attributable to cell damage, as judged by the absence of release of cytosolic enzyme markers and the ability to exclude trypan blue dye. Pulse-chase analysis and subcellular fractionation of AtT20 cell extracts suggested that the mechanism of EP24.15 secretion is not solely via classical secretory pathways, Additionally, drugs which disrupt the classical secretory pathway, such as Brefeldin A and nocodazole, blocked A23187-stimulated EP24.15 release yet had no effect on basal EP24.15 release, suggesting differences in the basal and stimulated pathways of secretion for EP24.15. In summary, EP24.15 appears to be secreted from AtT20 pituitary cells into the extracellular milieu, where the enzyme can participate in the physiologic metabolism of neuropeptides.

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Low-density seedings of yeast cells of Paracoccidioides brasiliensis give poor growth (as assessed by plating efficiency test) on conventional mycological agar media, and therefore growth-promoting factors for this fungus were sought. Water-extracts of yeast cells of six P. brasiliensis isolates were all considerably effective in promoting the growth of low-density seedings of P. brasiliensis isolates Pb-18 and Hachisuga, but had little effect on isolate Bt-4. Horse serum, at a concentration range of 2-4%, moderately or considerably promoted the growth of these P. brasiliensis isolates. Combinations of the fungus cell extracts with horse serum were highly effective in promoting the growth of all of the fungal isolates. The fungus cell extracts showed siderophore (microbial iron carrier) activity. An iron-chelator, ethylenediaminetetraacetic acid, at a concentration of 100 μM also highly promoted the growth of the fungal isolates in the presence of horse serum, and ferric ion added to culture medium was considerably effective in the growth promotion. These results suggest that deficient utilization of external iron by the fungus cell is one of the growth-limiting processes for low-density seedings of yeast cells of P. brasiliensis on conventional mycological agar media.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In the present study, 1220 plant extracts obtained from 352 plants belonging to 73 families that grow in the Amazon and Atlantic rain forests were screened for cytotoxicity against PC-3 prostate cancer cell lines. Extracts were tested in the single dose of 100 mu g/mL. Activity was observed in 17 aqueous or organic extracts belonging to Annonaceae, Apocynaceae, Araceae, Capparaceae, Commelinaceae, Flacourtiaceae, Lecythiclaceae, Leguminosae, Passifloraceae, Rutaceae, and Violaceae.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)