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Micropartículas de quitosana e óleo essencial de cúrcuma no controle in vitro de cryptococcus spp.: atividade antifúngica em células planctônicas, biofilmes e interação com antifúngicos

2026-04-14T18:41:38Z

Título: Micropartículas de quitosana e óleo essencial de cúrcuma no controle in vitro de cryptococcus spp.: atividade antifúngica em células planctônicas, biofilmes e interação com antifúngicos Autor(es): Silva, Maria Isabel de Souza Abstract: Species of the Cryptococcus neoformans/Cryptococcus gattii complex are encapsulated yeasts responsible for cryptococcosis, an opportunistic mycosis that affects humans and animals, particularly immunocompromised individuals. Planktonic and biofilm susceptibilities, the interaction with classical antifungal agents already used in the treatment of cryptococcosis, and the cytotoxicity profile of chitosan microparticles associated with turmeric essential oil against species of the Cryptococcus neoformans/Cryptococcus gattii complex were evaluated. Planktonic susceptibility and mature biofilm susceptibility assays were performed following standardized protocols, using crystal violet staining for biomass quantification and the MTT assay to assess metabolic activity. In addition, for chitosan microparticles loaded with turmeric essential oil, the checkerboard method was employed to evaluate interactions with classical antifungal agents, and cytotoxicity was assessed through cell viability assays in cell cultures. Statistical analyses were performed considering p < 0.05. After exposure to different concentrations, the minimum inhibitory concentration (MIC) ranges for chitosan microparticles containing turmeric essential oil were 4–256 μg/mL for 50% inhibition and 256–1024 μg/mL for 100% inhibition. For mature biofilms, the main tested compound was able to inhibit up to 33% of biomass at the highest concentration (256 μg/mL) and to reduce metabolic activity by up to 42% at the same concentration. The test compound showed an indifferent interaction when combined with amphotericin B and fluconazole, with no evidence of synergism or antagonism. Cytotoxicity was observed at a concentration of 400 μg/mL, reducing cell viability by nearly 75%. Finally, chitosan microparticles loaded with turmeric essential oil demonstrated antifungal activity against planktonic cells and mature biofilms of the Cryptococcus neoformans/Cryptococcus gattii species complex in in vitro assays. Tipo: Dissertação

Células dendríticas foliculares: avaliação imunofenotípica no linfoma de Hodgkin clássico subtipo esclerose nodular

2026-03-20T13:24:33Z

Título: Células dendríticas foliculares: avaliação imunofenotípica no linfoma de Hodgkin clássico subtipo esclerose nodular Autor(es): Almeida, Juliêta Maria Mendes Frota de Abstract: The follicular dendritic cells are the most important antigen presenting cells and have an important role in B cell immune response. Classic Nodular Sclerosis Hodgkin's Lymphoma (CNSHL) is a lymphoid neoplasm, more specifically from germinal center (GC) B cells, presenting with aggregates of follicular dendritic cells (FDC), Hodgkin/Reed Sternberg cells and variants and B cells forming complexes related to the GC, suggesting an association between nodular sclerosis and germinal center formation. CNSHL represents 70% of classic Hodgkin's lymphomas and has a favorable prognosis. Histologically it is characterized by a nodular pattern, collagen bands and lacunar cells. The goal of this study was the evaluation of the follicular dendritic cell by immunophenotyping with pS100 and fascin, in lymph node or mediastinal mass biopsies from patients with previously diagnosed classic nodular sclerosis Hodgkin's Lymphoma, trying to identify criteria as prognostic factors. 159 charts were reviewed and 38 patients were selected for the study. From the selected group 55.2% were males with a male to female ratio of 1.23:1 and a median age of 29.3 years. 52.6% were in clinical stage 1-11 and 68.4% had systemic symptoms (B). Multiple or isolated peripheral adenomegaly was present in all cases. The first lymph node site was cervical in 58% of the cases. 38 biopsy specimens were analysed and 57.9% were of nodular sclerosis subtype II. Immunohistochemistry showed 100% positivity for CD30 and 68.4% for CD15. The follicular dendritic cells were identified by pS100 and fascin antibodies through the Peroxidase-antiperoxidase Streptavidin avidin-biotin indirect immunoenzimatic technique, which was performed in pre-treated slides with the biopsy specimens included in paraffin blocks. The marking with pS100 didn't show good visualization of the network of follicular dendritic cells, and was useful as a generic marker. Fascin was the gold-standard for follicular dendritic cells, showing its positivity by the brown color. The CDF1 pattern was present in 7.9%, CDF2 in 47.4% and CDF3 in 44.7%. There was no relation between the presence of the follicular dendritic cell and sex, age, clinical stage, laboratorial parameters, or response to treatment, but a tendency for the association (p=0.056) between the subtypes of classical nodular sclerosis Hodgkin's lymphoma was demonstrated. The patients with follicular dendritic cells present in their biopsies have been watched for a longer period of time of about 32.9 months. This enabled a significant statistical association (p=0.001) between the presence of follicular dendritic cells and length of follow-up Tipo: Dissertação

Avaliação da contratilidade e do estresse oxidativo em íleo e cólon e análise proteômica do plasma de camundongos C57BL6J expostos ao metilmercúrio

2026-01-21T16:07:23Z

Título: Avaliação da contratilidade e do estresse oxidativo em íleo e cólon e análise proteômica do plasma de camundongos C57BL6J expostos ao metilmercúrio Autor(es): Buzaglo, Alexander Vasconcelos Abstract: Methylmercury (MeHg) is an organic mercury (Hg) compound with high toxicity due to its easy absorption after exposure. MeHg rapidly distributes throughout all tissues, crossing the blood-brain barrier and the epithelial barrier in the central nervous system and gastrointestinal tract, respectively, and can lead to a wide range of debilitating symptoms and death. The aim of this study was to elucidate the effects of oral methylmercury chloride exposure on body weight gain, intestinal motility, oxidative stress, and the proteomic profile in the plasma of intoxicated animals compared with the control group. For this purpose, 46 adult male C57BL6 mice from the animal facility of the Drug Development Center (NPDM) under pathogen-free conditions were used. Mice aged 60 to 90 days with body weights between 15 and 20 g, were divided into two groups: the control group receiving a saline solution by gavage and the intoxicated group receiving a methylmercury chloride solution (2 mg/kg diluted in saline) by gavage for 14 consecutive days. All animals were weighed every 3 days. Seven days after the end of intoxication, the animals were euthanized, and samples of hair, blood, duodenum, ileum, and colon were collected. Quantification of Hg in the hair, evaluation of ileum and colon contractility ex vivo, in a bath chamber for isolated tissues after exposure to potassium chloride (20-160 mM) and carbachol (0.1-100μM), evaluation of oxidative stress in the ileum and colon (tissue concentrations of glutathione-GSH, malondialdehyde-MDA and catalase-CAT) and proteomic analysis of plasma were performed. A significant reduction in the curve of percentage weight gain (% of initial weight) (p<0.05) when compared to the control group. Furthermore, elevated Hg levels in the hair were observed in the intoxicated group compared to the control group (Difference between means ± SEM: 6067 ± 2180). There was no significant difference in intestinal contractility in the ileum or colon between the groups. A significant increase in GSH was detected in the colon and a significant increase of CAT in the ileum of intoxicated animals (p=0.05). Significant alterations were observed in the proteomics analyses between groups, notably an increase in the expression of apolipoproteins E and H and a reduction in phosphatidylcholinesterol acetyltransferase, suggesting metabolic alterations; an increase in the expression of complement factor I, the Mu constant of the heavy chain and the C region of the Ig alpha chain, and a reduction in the C9 and C4b components of the complement system, suggesting a systemic response. We also observed an increase in the expression of the fibrinogen alpha chain and coagulation factor X and a reduction in the expression of the fibrinogen beta chain, suggesting altered liver function and prothrombotic conditions; a reduction in selenoprotein P, expected in models of mercury intoxication without selenium supplementation, indicating deficiencies in this element caused by mercury intoxication; and a reduction in peroxiredoxin 2 levels, that may affect the net antioxidant capacity. In summary, these results corroborate the known deleterious effects of mercury toxicity on the intestinal tract and contribute to the identification of potential proteomic biomarkers. Further studies are needed to confirm these findings, especially in clinical trials. Tipo: Dissertação

Síndromes mielodisplásticas [manuscrito] : caracterizacão morfológica e imunohistoquímica quanto a expressão da proteína p 53

2025-12-12T16:21:30Z

Título: Síndromes mielodisplásticas [manuscrito] : caracterizacão morfológica e imunohistoquímica quanto a expressão da proteína p 53 Autor(es): Magalhães, Silvia Maria Meira Abstract: Summary The p53 gene is currenuy thought to be a tumor suppressor gene, and its alterauons have been suggested to be involved m the pathogenesis of several human malignajicies. The piirpose of fhe present study was fhe evaluation of histológica! findings and the uiununohistochemical study ofp53 egression on bone marrow biopsy from uiirty- three patients in which a myelodysplasuc syndrome (MDS) was diagnosed. Forty- three bone marrow biopsies were reü-ospecüvely reviewed, and relationship among the different histological parajmeters as weU as clinicopafhological correlations were looked for. Histological analysis showed in 78,8% of cases a hypercellular, in 12,1% a hypocellular and in 9,1% a norniocellular bone marrow. Dysraegakaryopoiesis was the inost prominent abnormality of the hematopoietic series, detected in 72,7% of cases. Abnormal localization of immature precursors occurred in 39,4% of patients and increase in reticulin fibers occurred in 34,4%. The frequency oflymphoid nodules in our cases (27.3%) was higher fhan that reported by others with no relauonship with age, but significanuy related to Üückenmg of Uie reticulin network . Nuclear accumulaüon ofp53 protein was foimd m 15,2% offhe cases whereas control subjects were imiformly negaüve for p53 protein. All the five MDS cases that exhibited positive p53 reaction had some kind of disease progression, namely a more advanced FAB subtype and/or acute leukenua. A p53 immunoreactivity was therefore significanuy related to biological aggressiveness and progression of the disease. The results suggest that p53 mutauons may contribute, albeit rarely, to the development of MDS and, once present, may confer a growth advantage to myeloid cells and therefore is useful for predicting the evoluüon. MDS is heterogeneous not only in its phenotype but also in the Kciolecular niechanism of its genesis and progression. More extended and detailed study is necessary to understand the molecular basis of MDS development. The major aim is a more specific and effective treatment of these pauents. Tipo: Dissertação