1000 resultados para salicylhydroxamic acid
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Rotavirus has been considered the main agent of infectious diarrhea especially among younger children. We addressed the prevalence of rotavirus-associated diarrhea and the diversity of circulating electropherotypes by immunochromatography and RNA electrophoresis. Stool samples were taken from 391 children (267 with diarrhea) from the lower socioeconomic stratum who sought treatment in the Hospital Infantil João Paulo II/Belo Horizonte, during 2005 and 2006. Rotavirus was detected in 79/20.2% of subjects, 64/24.0% with diarrhea and 15/12.1% with no diarrhea. The virus was strongly associated with diarrhea (p = 0.003). A total of 76/19.4% and 69/17.6% rotavirus-positive children were identified by immunochromatography and electrophoresis, respectively. Rotavirus-associated diarrhea was more frequently detected in dry months (p < 0.001) and almost exclusively in children aged up to three years. Long profile strains prevailed (54/78.3%) but a shift toward short electropherotype was identified. Despite the decrease seen in 2006, rotavirus infection is still very common in our area. Although viral RNA electrophoresis is useful as a typing method, it should not be used exclusively in the diagnosis of rotavirus infection. We confirmed a shift from long to short profile strains, as already described for other South American countries.
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Dissertação para obtenção do Grau de Mestre em Biotecnologia
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Normal human metabolism leads to the daily production of large amounts of volatile and non-volatile acids. The maintenance of the pH within physiological limits is a demanding task in which several mechanisms are involved. The most immediate answer comes from several physiological buffers that quickly neutralize pH deviations caused by the addition of strong acids or bases to the body. Bicarbonate/carbonic acid is the most important buffer pair of the extracellular milieu, but is chemically inefficient and depends on the continuous activity of the lung and kidney. Other physiological buffers have higher efficacy and are very important in the intracellular environment and renal tubules. The capacity of the various chemical buffers is kept by operating in an open system and by several controlling mechanisms. The lung is responsible for the elimination of the carbon dioxide (CO2) produced in the body. In metabolic disorders, respiratory adjustment of the elimination of CO2 prolongs the effect of the bicarbonate/carbonic acid buffer, but this process consumes bicarbonate. The kidney contributes to acid-base balance through several mechanisms: 1) controls the reabsorption of filtered bicarbonate; 2) regenerates bicarbonate consumed in buffer reactions; 3) eliminates non-volatile acids. Renal elimination of acid and bicarbonate regeneration is only possible due to the existence of several urinary buffers and to the ability of the kidneys to produce ammonia
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Biochemistry, 2003, 42 (10), pp 3070–3080 DOI: 10.1021/bi026979d
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BACKGROUND: High-grade gliomas are aggressive, incurable tumors characterized by extensive diffuse invasion of the normal brain parenchyma. Novel therapies at best prolong survival; their costs are formidable and benefit is marginal. Economic restrictions thus require knowledge of the cost-effectiveness of treatments. Here, we show the cost-effectiveness of enhanced resections in malignant glioma surgery using a well-characterized tool for intraoperative tumor visualization, 5-aminolevulinic acid (5-ALA). OBJECTIVE: To evaluate the cost-effectiveness of 5-ALA fluorescence-guided neurosurgery compared with white-light surgery in adult patients with newly diagnosed high-grade glioma, adopting the perspective of the Portuguese National Health Service. METHODS: We used a Markov model (cohort simulation). Transition probabilities were estimated with the use of data from 1 randomized clinical trial and 1 noninterventional prospective study. Utility values and resource use were obtained from published literature and expert opinion. Unit costs were taken from official Portuguese reimbursement lists (2012 values). The health outcomes considered were quality-adjusted life-years, lifeyears, and progression-free life-years. Extensive 1-way and probabilistic sensitivity analyses were performed. RESULTS: The incremental cost-effectiveness ratios are below €10 000 in all evaluated outcomes, being around €9100 per quality-adjusted life-year gained, €6700 per life-year gained, and €8800 per progression-free life-year gained. The probability of 5-ALA fluorescence-guided surgery cost-effectiveness at a threshold of €20000 is 96.0% for quality-adjusted life-year, 99.6% for life-year, and 98.8% for progression-free life-year. CONCLUSION: 5-ALA fluorescence-guided surgery appears to be cost-effective in newly diagnosed high-grade gliomas compared with white-light surgery. This example demonstrates cost-effectiveness analyses for malignant glioma surgery to be feasible on the basis of existing data.
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Devido a crescente importância dos coccídios intestinais (Cryptosporidium, Isospora e Cyclospora) como parasitos oportunistas, é fundamental para os laboratórios diferenciar morfologicamente estes protozoários; a técnica de Ziehl-Neelsen modificada (ZNm) é amplamente utilizada para este fim; recentemente, foi proposto um novo procedimento, a coloração combinada do ácido tricrômico (Acid-Fast-Trichrome - AFT). O objetivo do presente estudo foi comparar os processos AFT e ZNm para a detecção destes coccídios em amostras fecais de pacientes portadores do vírus VIH. Foram selecionados dois grupos de indivíduos, para inclusão no estudo, segundo a presença (n=60) ou ausência de diarréia (n=60). As amostras de fezes foram coletadas em solução de formalina 10% e os esfregaços fecais preparados i) diretamente das fezes e ii) após concentração prévia a 500xg (10 minutos), foram submetidos aos diferentes processos de coloração. Considerando-se a positividade por técnica (AFT e ZNm), verificou-se a superioridade do procedimento de ZNm (n=19; 100% dos casos positivos) sobre o de AFT (n=8; 42,1%). Ambos possibilitaram a identificação dos 101 casos verdadeiramente negativos. Coccidiose intestinal foi mais frequente entre os pacientes que apresentaram diarréia (26,6%) em comparação à positividade observada entre os indíviduos assintomáticos (5%) sendo que C. cayetanensis não foi detectada em ambos os grupos. Foi de nosso interesse avaliar a aplicabilidade da técnica AFT para a coloração deste protozoário. Devido à sensibilidade e especificidade obtida neste estudo (100%), conclui-se que o método de ZNm continua sendo o mais indicado para o diagnóstico da criptosporidiose e isosporose, principalmente quando associado ao procedimento de centrífugo-concentração (500xg, 10 minutos). Embora a coloração AFT tenha baixo custo, faz-se necessário o seu aperfeiçoamento pois este procedimento permite o diagnóstico simultâneo dos coccídios intestinais (C. parvum, I. belli e C. cayetanensis) e dos microsporídios.
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A thesis submitted for the Degree of Master in Medical microbiology
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Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina
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Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica
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INTRODUCTION: Candida yeasts are commensals; however, if the balance of normal flora is disrupted or the immune defenses are compromised, Candida species can cause disease manifestations. Several attributes contribute to the virulence and pathogenicity of Candida, including the production of extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate the in vitro activity of phospholipases and acid proteinases in clinical isolates of Candida spp. METHODS: Eighty-two isolates from hospitalized patients collected from various sites of origin were analyzed. Phospholipase production was performed in egg yolk medium and the production of proteinase was verified in a medium containing bovine serum albumin. The study was performed in triplicate. RESULTS: Fifty-six (68.3%) of isolates tested were phospholipase positive and 16 (44.4%) were positive for proteinase activity. C. tropicalis was the species with the highest number of positive isolates for phospholipase (91.7%). Statistically significant differences were observed in relation to production of phospholipases among species (p<0,0001) and among the strains from different sites of origin (p=0.014). Regarding the production of acid protease, the isolates of C. parapsilosis tested presented a larger number of producers (69.2%). Among the species analyzed, the percentage of protease producing isolates did not differ statistically (χ2=1.9 p=0.5901 (χ2=1.9 p=0.5901). CONCLUSIONS: The majority of C. non-albicans and all C. albicans isolates were great producers of hydrolytic enzymes and, consequently, might be able to cause infection under favorable conditions.
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Amino acid insertions in the protease have rarely been described in HIVinfected patients. One of these insertions has recently been described in codon 35, although its impact on resistance remains unknown. This study presents a case of an HIV variant with an insertion in codon 35 of the protease, described for the first time in Bauru, State of Sao Paulo, Brazil, circulating in a 38-year-old caucasian male with asymptomatic HIV infection since 1997. The variant isolated showed a codon 35 insertion of two amino acids in the protease: a threonine and an aspartic acid, resulting in the amino acid sequence E35E_TD.
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INTRODUCTION: Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. METHODS: Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. RESULTS: In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. CONCLUSIONS: FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.
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INTRODUCTION: Metallo-β-lactamase (MBL) has been reported all over the world. METHODS: The inhibitory effect of mercaptopropionic acid (MPA) on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC) for multidrug-resistant Acinetobacter baumanni strains. RESULTS: MPA significantly inhibited growth of the strains. CONCLUSIONS: The use of MPA can affect the results in phenotypic methods of MBL detection.
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RESUMO: Introdução: Uma meta-análise recente demonstrou que uso adjuvante de ácido zoledrónico (AZ) em mulheres pós-menopáusicas com cancro da mama precoce (CM) conduz a redução do risco de morte por CM em 17%. Investigámos o efeito do estado hormonal (pré [PrM] vs pós-menopausa tardia [PoM]) na remodelação óssea e controlo de doença em mulheres com CM e metástases ósseas (MO) tratadas com AZ e quimioterapia (QT). Métodos: Neste estudo de coorte retrospetivo, colhemos variáveis clinico-patológicas e quantificámos o telopéptido N-terminal (NTX) urinário e marcadores tumorais (MT) séricos em mulheres com CM e MO tratadas com QT e AZ. As doentes foram divididas em PrM (<45 anos) e PoM (>60 anos). Endpoints do estudo: variação do NTX, CA15.3 e CEA nos meses 3, 6 e 9, tempo até falência de QT de primeira-linha e sobrevivência. Quando apropriado foram usados os testes de Wilcoxon rank-sum, modelo de efeitos lineares mistos, teste log-rank e modelo de Cox. Resultados: Quarenta doentes foram elegíveis para análise (8 PrM e 32 PoM). Depois da introdução de AZ e QT, os níveis de NTX e MT caíram no coorte global. O perfil de resposta não diferiu entre grupos no mês 3 ou em tempos posteriores (valor-p para interação tempo-estado hormonal no mês 3=0.957). Ademais, o perfil de resposta dos MT também não diferiu entre grupos. O tempo mediano até falência de primeira-linha de QT em PrM e PoM foi de 15.2 e 17.4 meses, respetivamente. Não foi identificada diferença significativa entre grupos, quer em análise univariada quer após controlo para envolvimento visceral (p=0.399 e 0.469, respetivamente). Igualmente, não houve diferenças em termos de sobrevivência. Conclusões: Neste coorte, não foram identificadas diferenças no controlo de NTX ou MT em função do estado menopausico. Igualmente, não foi identificada diferença no tempo até falência de primeira-linha de CT ou sobrevivência.----------- ABSTRACT: Background: A recent meta-analysis showed that the adjuvant use of zoledronic acid (ZA) in postmenopausal women with early breast cancer (BC) leads to a reduction in the risk of breast cancer death by 17%. We investigated the effect of the hormonal status (pre [PrM] vs late post menopause [PoM]) on bone turnover and disease control among women with BC and boné metastases (BM) treated with ZA and chemotherapy (CT). Methods: In this retrospective cohort study, we collected clinicopathologic variables, urinary Nterminal telopeptide (NTX) and serum tumor marker levels from women with BC and BM treated with CT and ZA. Patients were divided in PrM (<45 years) and PoM (>60 years). Study endpoints were NTX, CA15.3 and CEA variation at 3, 6 and 9 months, and time to first-line CT failure and survival. We performed multilevel mixed-effects linear regression models to assess the variation of repeated measures and cox regression models for time to event outcomes. Results: Forty patients were eligible for analysis (8 PrM and 32 PoM). After introduction of ZA and CT, NTX and tumor markers declined in the overall cohort. Response profile was similar between menopausal groups at month 3 and at later time points (p-value for time-hormonal status interaction at month 3=0.957). Furthermore, tumor markers response profile was also equal between groups. Median time to first-line CT failure in PrM and PoM women was 15.2 and 17.4 months, respectively. No significant difference between groups was found, either using a univariate analysis or after controlling for visceral disease involvement (p=0.399 and 0.469, respectively). Likewise, no differences in survival were found. Conclusions: In this cohort, no differences were found in terms of NTX or tumor markers control according to menopausal status. Similarly, no difference in time to first-line CT failure or survival was found.
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INTRODUCTION: The aim of the present study was to analyze the larvicidal activity of different crude extracts of Larrea cuneifolia and its most abundant lignan, nordihydroguaiaretic acid (NDGA), against Culex quinquefasciatus. METHODS: Chloroform, methanol, and aqueous extracts from L. cuneifolia and NDGA were tested against larvae of Cx. quinquefasciatus under laboratory conditions. RESULTS: The chloroform extract showed the highest larvicidal effect, with an estimated LC50 of 0.062 mg/ml. NDGA also demonstrated significant larvicidal activity with an estimated LC50 of 0.092 mg/ml. CONCLUSIONS: These results indicate that the chloroform extract of L. cuneifolia and NDGA are promising insecticides of botanical origin that could be useful for controlling Cx. quinquefasciatus.