3,523 research outputs found
Genotipagem do vírus da hepatite B de pacientes crônicos com resistência ao tratamento com lamivudina na Cidade de Ribeirão Preto, Estado de São Paulo
INTRODUCTION: Lamivudine is a nucleoside analogue that is used clinically for treating chronic hepatitis B infection. However, the main problem with prolonged use of lamivudine is the development of viral resistance to the treatment. Mutations in the YMDD motif of the hepatitis B virus DNA polymerase gene have been associated with resistance to drug therapy. So far, there have not been many studies in Brazil reporting on genotype-dependent development of resistance to lamivudine. Thus, the aim of the present study was to determine the possible correlation between a certain genotype and increased development of resistance to lamivudine among chronic hepatitis B patients. METHODS: HBV DNA in samples from 50 patients under lamivudine treatment was amplified by means of conventional PCR. Samples were collected at Hospital das Clínicas, FMRP-USP. The products were then sequenced and phylogenetic analysis was performed. RESULTS: Phylogenetic analysis revealed that 29 (58%) patients were infected with genotype D, 20 (40%) with genotype A and one (2%) with genotype F. Mutations in the YMDD motif occurred in 20% of the patients with genotype A and 27.6% of the patients with genotype D. CONCLUSIONS: Despite the small number of samples, our results indicated that mutations in the YMDD motif were 1.38 times more frequent in genotype D than in genotype A.INTRODUÇÃO: Lamivudina é um análogo de nucleosídeo clinicamente utilizado para o tratamento da infecção crônica pela hepatite B. Entretanto, o principal problema do uso prolongado da lamivudina é o desenvolvimento de resistência viral ao tratamento. Mutações no motivo YMDD no gene da DNA polimerase do vírus da hepatite B estão associados com a resistência a terapia medicamentosa. Até o presente momento, não há muitos estudos no Brasil que descrevem o desenvolvimento genótipo-dependente da resistência à lamivudina. Assim, o intuito do trabalho aqui descrito foi determinar a possível correlação entre um determinado genótipo e o desenvolvimento aumentado da resistência à lamivudina em pacientes com hepatite B crônica. MÉTODOS: O HBV DNA foi amplificado por PCR convencional a partir de 50 amostras coletadas de pacientes submetidos ao tratamento com lamivudina no Hospital das Clínicas- FMRP- USP. Posteriormente, os produtos foram seqüenciados e a análise filogenética foi realizada. RESULTADOS: A análise filogenética mostrou que 29 (58%) pacientes foram infectados com o genótipo D, 20 (40%) com o genótipo A e 1 (2%) com o genótipo F. Mutações no motivo YMDD ocorreu em 20% dos pacientes com genótipo A e 27,6% em pacientes do genótipo D. CONCLUSÕES: Apesar do baixo número de amostras, nossos resultados indicaram que mutações no motivo YMDD são 1,38 X mais frequentes no genótipo D em relação ao genótipo A.Universidade de São Paulo USP - FCFR
Mineralização dos resíduos provenientes da secagem da pimenta-do-reino quando aplicados ao solo
The use of residues from the black pepper bean drying process as fertilizer for agricultural crops implies the need to know the dynamics of their decomposition and release of the nutrients to guide it’s management, especially regarding the best time of its application in the soil. This study aimed to evaluate the dynamics of organic carbon and nitrogen during the mineralization process of this residue. The experiment was conducted in a completely randomized design with ten treatments related to different post-disposal periods to the soil (0, 7, 13, 20, 27, 34, 48, 69, 98, 147 days). Samples were collected to quantify easily oxidized organic carbon (OCeo), organic nitrogen (ON) and the determinations of their respective mineralized fractions. The evaluation of OCeo mineralization, being more stable and less susceptible to climatic variations, was the most appropriate for estimating the mineralized fraction of the residue. The application of the residue in dystrophic Yellow Red Latosol soil during the month of August provides, after 140 days, OCeo and ON mineralized fractions around 99 and 60%, respectively, in the climatic conditions of Espirito Santo state, Brazil.A utilização de resíduos do processo de secagem de pimenta-do-reino como fertilizante de lavouras deve considerar a dinâmica de sua decomposição e liberação dos nutrientes, para orientar o seu manejo, principalmente quanto à melhor época de sua aplicação no solo. Este estudo teve como objetivo avaliar a dinâmica do carbono orgânico e do nitrogênio durante o processo de mineralização desse resíduo. O experimento foi conduzido em delineamento inteiramente casualizado com dez tratamentos, correspondentes ao tempo de pós-disposição ao solo (0, 7, 13, 20, 27, 34, 48, 69, 98, 147 dias), quando amostras foram coletadas para a determinação de carbono orgânico facilmente oxidado (OCeo), nitrogênio orgânico (ON) e suas respectivas frações mineralizadas. A avaliação da mineralização do OCeo, por ser mais estável e menos suscetível às variações climáticas, foi a mais apropriada para a estimativa da fração mineralizada do resíduo. A aplicação do resíduo em solo de Latossolo Vermelho Amarelo distrófico durante o mês de agosto proporciona, após 140 dias, frações mineralizadas OCeo e ON em torno de 99 e 60%, respectivamente, nas condições climáticas do estado do Espírito Santo, Brasil
Estrutura de comércio inter-regional no Brasil: uma análise espacial de insumo-produto para o período 1996 e 2002
Development of a molecular platform for HTLV confirmatory diagnosis: importance of the internal amplification control
Pulmonary metastasectomy from soft tissue sarcomas
INTRODUCTION: Isolated pulmonary metastases from soft tissue sarcomas occur in 20-50% of these(the issue is about metastases, not lung cancer )patients, and 70% of these patients will present disease limited only to the lungs. Surgical resection is well accepted as a standard approach to treat metastases from soft tissue sarcomas isolated in the lungs, and many studies investigating this technique have reported an overall 5-year survival ranging from 30-40%. The most consistent predictor of survival in these patients is complete resection. The aim of the present study was to determine the demographics and clinical treatment-related variables associated with long-term (90-month) overall survival in patients with lung metastases undergoing pulmonary metastasectomy from soft tissue sarcomas. METHODS: We performed a retrospective review of patients admitted in the Thoracic Surgery Department with lung metastases who underwent thoracotomy for resection following treatment of the primary tumor. Data regarding primary tumor features, demographics, treatment, and outcome were collected. RESULTS: One hundred twenty-two thoracotomies and 273 nodules were resected from 77 patients with previously treated soft tissue sarcomas. The median follow-up time of all patients was 36.7 months (range: 10-138 months). The postoperative complication rate was 9.1%, and the 30-day mortality rate was 0%. The 90-month overall survival rate for all patients was 34.7%. Multivariate analysis identified the following independent prognostic factors for overall survival: the number of metastases resected, the disease-free interval, and the number of complete resections. CONCLUSION: These results confirm that lung metastasectomy is a safe and potentially curative procedure for patients with treated primary tumors. A select group of patients can achieve long-term survival after lung resection
Mechanistic investigation into the selective anticancer cytotoxicity and immune system response of surface-functionalised, dichloroacetate-loaded, UiO-66 nanoparticles
The high drug loading and excellent biocompatibilities of metal-organic frameworks (MOFs) have led to their application as drug delivery systems (DDSs). Nanoparticle surface chemistry dominates both biostability and dispersion of DDSs while governing their interactions with biological systems, cellular and/or tissue targeting, and cellular internalisation, leading to a requirement for versatile and reproducible surface functionalisation protocols. Herein, we explore not only the effect of introducing different surface functionality to the biocompatible Zr-MOF UiO-66, but also the efficacy of three surface modification protocols: (i) direct attachment of biomolecules (folic acid, biotin) introduced as modulators of UiO-66 synthetic, (ii) our previously reported ‘’click-modulation” approach to covalently attach polymers (poly(ethylene glycol), poly-L-lactide, poly-N-isopropylacrylamide) to the surface of UiO-66 through click chemistry, and (iii) surface ligand exchange, to postsynthetically coordinate folic acid, biotin and heparin to UiO-66. The innovative use of a small molecule with metabolic anticancer activity, dichloroacetic acid (DCA), as a modulator during synthesis is described, and found to be compatible with all three protocols, yielding surface-coated, DCA-loaded (10-20% w/w) nanoMOFs (70-170 nm). External surface modification generally enhances stability and colloidal dispersion of UiO-66. Cellular internalisation routes and efficiencies of UiO-66 by HeLa cervical cancer cells can be tuned by surface chemistry, and anticancer cytotoxicity of DCA-loaded MOFs correlates with endocytosis efficiency and mechanisms. The MOFs with the most promising coatings (folic acid, poly(ethylene glycol), poly-L-lactide, and poly-N-isopropylacrylamide) were extensively tested for selectivity of anti-cancer cytotoxicity against MCF-7 breast cancer cells and HEK293 healthy kidney cells, as well as for cell proliferation and ROS production against J774 macrophages and peripheral blood lymphocytes (PBLs) isolated from the blood of human donors. DCA-loaded, folic acid modified UiO-66 selectively kills cancer cells without harming healthy ones or provoking immune system response in vitro, suggesting a significant targeting effect and great potential in anticancer drug delivery. The results provide mechanistic insight into the design and functionalisation of MOFs for drug delivery, and underline the availability of various in vitro techniques to potentially minimise early-stage in vivo animal studies, following the three Rs: reduction, refinement and replacement
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