596 research outputs found
Endophytic Fungi of Tropical Forests: A Promising Source of Bioactive Prototype Molecules for the Treatment of Neglected Diseases
Surface topography of hydroxyapatite affects ROS17/2.8 cells response
Hydroxyapatite (HA) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute.
The aim of this investigation was to study the effect of surface topography produced by the presence of microporosity on cell response, evaluating: cell attachment, cell morphology, cell proliferation, total protein content, and alkaline phosphatase (ALP) activity. HA discs with different percentages of microporosity (< 5%, 15%, and 30%) were confected by means of the combination of uniaxial powder pressing and different sintering conditions. ROS17/2.8 cells were cultured
on HA discs. For the evaluation of attachment, cells were cultured for two hours. Cell morphology was evaluated
after seven days. After seven and fourteen days, cell proliferation, total protein content, and ALP activity were measured. Data were compared by means of ANOVA and Duncan’s multiple range test, when appropriate. Cell attachment (p = 0.11) and total protein content (p = 0.31) were not affected by surface topography. Proliferation after 7 and 14 days (p = 0.0007 and p = 0.003, respectively), and ALP activity (p = 0.0007) were both significantly decreased by the most irregular surface (HA30). These results suggest that initial cell events were not affected by surface topography, while surfaces with more regular topography, as those present in HA with 15% or less of microporosity, favored intermediary and final events such as cell proliferation and ALP activity
Multi-elemental contamination and historic record in sediments from the Santos-Cubatão Estuarine System, Brazil
This paper records for the first time the contamination history and identifies the sources of 38 elements in sediments from the Santos-Cubatão Estuarine System (SE Brazil), at one of the most industrialized areas in Latin America. The compositions of samples from a 260 cm long sediment core collected in the Morrão River estuary were determined by ICP-MS. Enrichment factors, principal component analysis, correlation matrixes, and the characterization of geochemical signatures permitted a consistent data evaluation. Contaminant elements such as Cr, Mn, Ni, Zn, Ga, Ag, Cd, Sn, Sb, Pb, and Bi were associated with steel plant-derived Fe concentrations, while Be, Ca, Sc, Co, Cu, Sr, Y, Zr, Nb, Hf, Ta, Th, and U were associated with fertilizer industry-derived P concentrations. An overlap of sedimentary Fe distribution and local steel plant production indicated that Fe is a reliable marker of the contamination history, allowing the estimation of sedimentation rates over a period of 45 years of industrial activities.Este trabalho registra pela primeira vez o histórico da contaminação e as fontes de 38 elementos em sedimentos do sistema estuarino de Santos-Cubatão (SE do Brasil), em uma das áreas mais industrializadas da América Latina. A composição de um testemunho de 260 cm de profundidade do estuário do rio Morrão foi determinada por ICP-MS e avaliada por meio de fatores de enriquecimento, análise de componentes principais, matrizes de correlação e assinaturas geoquÃmicas. Elementos contaminantes como Cr, Mn, Ni, Zn, Ga, Ag, Cd, Sn, Sb, Pb e Bi foram associados ao Fe, derivados de atividades siderúrgicas, enquanto Be, Ca, Sc, Co, Cu, Sr, Y, Zr, Nb, Hf, Ta, Th e U estiveram associados ao P, relacionados ao processo produtivo de fertilizantes. Uma sobreposição da distribuição do Fe sedimentar e produção local de aço indicaram que o Fe é um marcador confiável do histórico da contaminação, permitindo a estimativa de taxas de sedimentação para 45 anos de atividades industriais.14901500Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Multi-elemental contamination and historic record in sediments from the Santos-Cubatão Estuarine System, Brazil
This paper records for the first time the contamination history and identifies the sources of 38 elements in sediments from the Santos-Cubatão Estuarine System (SE Brazil), at one of the most industrialized areas in Latin America. The compositions of samples from a 260 cm long sediment core collected in the Morrão River estuary were determined by ICP-MS. Enrichment factors, principal component analysis, correlation matrixes, and the characterization of geochemical signatures permitted a consistent data evaluation. Contaminant elements such as Cr, Mn, Ni, Zn, Ga, Ag, Cd, Sn, Sb, Pb, and Bi were associated with steel plant-derived Fe concentrations, while Be, Ca, Sc, Co, Cu, Sr, Y, Zr, Nb, Hf, Ta, Th, and U were associated with fertilizer industry-derived P concentrations. An overlap of sedimentary Fe distribution and local steel plant production indicated that Fe is a reliable marker of the contamination history, allowing the estimation of sedimentation rates over a period of 45 years of industrial activities
BitTorrent-Like Protocols for Interactive Access to VoD Systems
This article presents two novel protocols for interactive access to video-on-demand systems. They are both based on the well-known BitTorrent paradigm. As main innovative aspects, the video chunks are categorized in different priority sets and there is the deployment of a user-behavior predicting model. The analysis and the validation are carried out through simulations using workloads from a real server. Furthermore, the novel protocols are compared with others of the literature. The final results outline optimizations of up to one order of magnitude over the various competitive metrics considered herein
BitTorrent-Like Protocols for Interactive Access to VoD Systems
This article presents two novel protocols for interactive access to video-on-demand systems. They are both based on the well-known BitTorrent paradigm. As main innovative aspects, the video chunks are categorized in different priority sets and there is the deployment of a user-behavior predicting model. The analysis and the validation are carried out through simulations using workloads from a real server. Furthermore, the novel protocols are compared with others of the literature. The final results outline optimizations of up to one order of magnitude over the various competitive metrics considered herein
Antimalarials and Phytotoxins from Botryosphaeria dothidea Identified from a Seed of Diseased Torreya taxifolia
The metabolic pathways in the apicoplast organelle of Plasmodium parasites are similar to those in plastids in plant cells and are suitable targets for malaria drug discovery. Some phytotoxins released by plant pathogenic fungi have been known to target metabolic pathways of the plastid; thus, they may also serve as potential antimalarial drug leads. An EtOAc extract of the broth of the endophyte Botryosphaeria dothidea isolated from a seed collected from a Torreya taxifolia plant with disease symptoms, showed in vitro antimalarial and phytotoxic activities. Bioactivity-guided fractionation of the extract afforded a mixture of two known isomeric phytotoxins, FRT-A and flavipucine (or their enantiomers, sapinopyridione and (-)-flavipucine), and two new unstable γ-lactam alkaloids dothilactaenes A and B. The isomeric mixture of phytotoxins displayed strong phytotoxicity against both a dicot and a monocot and moderate cytotoxicity against a panel of cell lines. Dothilactaene A showed no activity. Dothilactaene B was isolated from the active fraction, which showed moderate in vitro antiplasmodial activity with high selectivity index. In spite of this activity, its instability and various other biological activities shown by related compounds would preclude it from being a viable antimalarial lead
Does Quantitative Left Ventricular Regional Wall Motion Change after Fibrous Tissue Resection in Endomyocardial Fibrosis?
OBJECTIVES: We compared left ventricular regional wall motion, the global left ventricular ejection fraction, and the New York Heart Association functional class pre- and postoperatively. INTRODUCTION: Endomyocardial fibrosis is characterized by fibrous tissue deposition in the endomyocardium of the apex and/or inflow tract of one or both ventricles. Although left ventricular global systolic function is preserved, patients exhibit wall motion abnormalities in the apical and inferoapical regions. Fibrous tissue resection in New York Heart Association FC III and IV endomyocardial fibrosis patients has been shown to decrease morbidity and mortality. METHODS: We prospectively studied 30 patients (20 female, 30±10 years) before and 5±8 months after surgery. The left ventricular ejection fraction was determined using the area-length method. Regional left ventricular motion was measured by the centerline method. Five left ventricular segments were analyzed pre- and postoperatively. Abnormality was expressed in units of standard deviation from the mean motion in a normal reference population. RESULTS: Left ventricular wall motion in the five regions did not differ between pre- and postoperative measurements. Additionally, the left ventricular ejection fraction did not change after surgery (0.45±0.13% x 0.43±0.12% pre- and postoperatively, respectively). The New York Heart Association functional class improved to class I in 40% and class II in 43% of patients postoperatively (p<0.05). CONCLUSIONS: Although endomyocardial fibrosis patients have improved clinical symptoms after surgery, the global left ventricular ejection fraction and regional wall motion in these patients do not change. This finding suggests that other explanations, such as improvements in diastolic function, may be operational
Estudo clÃnico duplo cego comparando praziquantel com oxamniquine
Com objetivo de se compararem a tolerabilidade e eficácia do praziquantel e oxamniquine, procedeu-se a um estudo prospectivo duplo-cego envolvendo 120 pacientes com esquistossomose intestinal ou hepatintestinal. Os pacientes foram randomizados em dois grupos. Um foi tratado com praziquantel, na dose de 55 mg/kg de peso, o outro com oxamniquine, 15 mg/kg de peso, sempre administrados em dose única por via oral. O diagnóstico e seguimento parasitológicos basearam-se ho exame de fazes peio método de Kate Katz. Em 73 de 77 casos negativos após tratamento, executaram-se biópsias retais. Efeitos colaterais, principalmente tontura, sonolência, dores abdominais, cefaléia, náuseas e diarréia foram observados em 87% dos casos. Sua incidência, intensidade e duração foram semelhantes em ambos os grupos, mas a dor abdominal foi significativamente mais freqüente após praziquantel, havendo maior tendência para tontura intensa após oxamniquine. Observou-se aumento significante de alamina-aminotransferase e gama-glutamiltransferase após oxamniquine e de bilirrubina total após praziquantel. Um total de 48 pacientes tratados com praziquantel e 46 com oxamniquine completaram os exames de controle até o sexto mês. As percentages de cura foram de 79,2% e de 84,8% respectivamente, diferença não significativa. Os pacientes não curados mostraram redução média do número de ovos de 93,5% e de 84,1%, diferença não significativa. Cinco pacientes retratados com praziquantel curaram-se, mas somente um de três retratados com oxamniquine. Estes resultados mostram, que ambas as drogas-apesar de diferentes propriedades farmacológicas provocam reações colaterais semelhantes e apresentam eficácia terapêutica comparável.A double-blind clinical trial involving 120 patients with chronic schistosomiasis was carried out to compare the tolerability and efficacy of praziquantel and oxamniquine. The patients were randomly allocated into two groups. One was treated with praziquantel, 55 mg/kg of body weight CBWT), and the other one with oxamniquine, 15mg/kg bwt, administered in a single oral dose. The diagnosis and the parasitological follow-up was based on stool examinations by quantitative Kato-Katz method and on rectal biopsies. Side-effects mainly dizziness, sleepness, abdominal distress, headache, nausea and diarrhea were observed in 87% of the cases. Their incidence, intensity and duration were similar for both drugs but abdominal pain was significantly more frequent after praziquantel intake and severe dizziness was more commonly reported after oxamniquine. A significant increase of alanine-aminotransferase and y-glutamyltransferase was found with the latter drug and of total bilirubin with the former one. A total of 48 patients treated with praziquantel and 46 with oxamniquine completed with negative findings the required three post-treatment parasitological controls three slides of each stool sample on the first, third and sixth month. The achieved cure rates were 79.2% and 84.8%, respectively, a difference without statistical significance. The non-cured cases showed a mean reduction in the number of eggs per gram of feces of 93.5% after praziquantel and of 84.1% after oxamniquine. This diference also was not significant. Five patients retreated with praziquantel were cured but only one out of three treated a second time with oxamniquine. These findings show that both drugs despite their different chemical structures, pharmacological properties and mechanisms-of-action induce similar side-effects as well as a comparable therapeutical efficacy, in agreement with the results reported from analogous investigations
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