98 resultados para Tetsuro Yoshida
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A different methodology was used to isolate and purify oxoaporphine alkaloids, as they are difficult to separate by the usual workup when in mixture. Alkaloid extracts from Annonaceae species were obtained by base/acid extraction. The extracts were concentrated and submitted to partition in solutions of acids of different pKa values, followed by separation by preparative TLC using 1 mm thick silica gel impregnated with oxalic acid (11.2% w/w). Liriodenine, lisycamine, lanuginosine, and O-methylmoschatoline were obtained and tested against tumoral cells (line Hep2, ATCC-CCL 23, larynx carcinoma). Only O-methylmoschatoline (IC50 12.4 µM) was more active than cisplatin (18.0 µM).
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Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of São Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees & Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia.
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Thermogravimetry (TG) and differential scanning calorimetry (DSC) are used in pharmaceutical studies for drugs characterization, purity, formulations compatibility, polymorphism identification, stability evaluation, and thermal decomposition of drugs and pharmaceutical formulations. Simvastatin showed fusion at 138.5 ºC and thermal stability up to 248 ºC. Simvastatin was incompatible with preservative excipient butylhydroxyanisole (BHA) performing a process of crystal amorphization. The drug showed morphological polymorphism, where it has the same unit cell but with different crystal habits according to the recrystallization solvent.
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Several matters of the pharmaceutical demonstrate the great importance of thermal analysis application, especially TG and DSC for the pharmaceutical industry future, namely: characterization of the drugs with the thermal events definition, in studies of drug purity, in the polymorphs identification, in compatibility studies of solid dosage pharmaceutical formulations, in drugs and pharmaceutical formulations thermal stability, and in determination of shelf life for isothermal degradation kinetics by extrapolation using the Arrhenius equation. Thus, the test results obtained from thermal analysis are directly related to the quality of a pharmaceutical product, whether the stability or bioavailability of the pharmaceutical product.
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In this study, an analytical method was developed and validated for quantitation of the drug bevacizumab (Avastin®) by high performance liquid chromatography (HPLC). The HPLC column was a BioSuite 250® HR SEC, 300 x 7.8 mm x 5 µm (Waters, USA). The mobile phase consisted of phosphate buffered saline (PBS). The results revealed that the method was specific, precise, accurate, robust and linear (r² = 0.998) from 5 to 75 µg mL-1. Therefore, this method can be used in drug release studies or in quality control ampoules of the drug.
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Cyclosporine-A-loaded PLGA implants were developed intended for ocular route. Implants were prepared using solvent extraction/evaporation technique followed by casting of the cake into rods in a heated surface. XRD patterns showed that cyclosporine-A was completely incorporated into PLGA. FTIR and DSC results indicated alterations on drug molecular conformation aiming to reach the most stable thermodynamic conformation at polymer/drug interface. Implants provided controlled/sustained in vitro release of the drug. During the first 7 weeks, the drug release was controlled by the diffusion of the cyclosporine-A; and between 7-23 week period, the drug diffusion and degradation of PLGA controlled the drug release.
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The neolignans are defined as dimers of allylphenol and propenylphenol between itself or crossed, whose bond does not occur by the 8-8' carbons like lignans. This review centered on stereochemical aspects of the hydrobenzofuran type, a widespread skeleton among neolignans. The chemical structures established based on spectrometric data are registered in the literature. The absolute configurations reported previously were determined by chiroptical techniques. Some chemical transformations with neolignans, performed in previous studies, afforded products which are accumulated in other vegetal species and contributed to assign the unknown stereochemistry of these natural compounds. Possible biosynthetic pathways are also proposed.
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AbstractSilicon oxycarbide glasses (SiOC) are a class of amorphous materials with a similar silica glass structure, in which oxygen atoms are partially replaced by tetracoordenated carbon atoms. The presence of carbon atoms covalently bound to the silicon atoms creates a more interconnected structure with better strength, and excellent chemical stability than conventional silica. SiOCs are easily prepared by the pyrolysis of polysiloxanes and can potentially be implemented in several technological applications that require high temperatures. This paper mainly addresses the preparation, structure, and properties of SiOC. Furthermore, potential applications of SiOC are also introduced.
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Os deslocamentos químicos de RMN 13C de carbonos a , b , g e d de 17 conjuntos de haletos (F, Cl Br e I) alifáticos, inclusive compostos mono, bi e tricíclicos, podem ser reproduzidos por uma equação linear de duas constantes e duas variáveis do tipo : d R-X = A*d R-X1 + B*d R-X2 onde A e B são constantes obtidas por regressão multilinear a partir de deslocamentos químicos de 13C; d R-X, o deslocamento químico de 13C do composto com halogênio (R-X); d R-X1 e d R-X2 deslocamentos químicos de outros haletos. Para brometos (R-X) alifáticos a melhor correlação foi obtida com os dados de fluoretos (R-X1) e iodetos (R-X2) com R2 de 0,9989 e desvio médio absoluto (DM) de 0,39ppm. Para cloretos (R-X) a melhor correlação foi com dados de brometos (R-X1) e iodetos (R-X2) com R2 de 0,9960 e DM de 0,76ppm. Para fluoretos (R-X) a melhor correlação foi com brometos (R-X1) e iodetos (R-X2) com R2 de 0,9977 e DM de 1,10ppm e para iodetos (R-X) foi com fluoretos (R-X1) e brometos (R-X2) com R2 de 0,9972 e desvio médio absoluto de 0,60 ppm.
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TLC autographic assays revealed in the hexane extract of Iryanthera juruensis (Myristicaceae) the presence of two compounds, with antioxidant properties towards beta-carotene. They were isolated and identified as 3-methyl-sargachromenol (1) and sargachromenol (2). Further investigation of the hexane extract led to isolations of 3-methyl-sargaquinoic acid (3) and sargaquinoic acid (4). The electrochemical behaviour of these compounds was studied in CH2Cl2/Bu4NBF4 at glassy carbon electrode. The phenolic group in both tocotrienols 1 and 2 are oxidized at +0.23V and +0.32V and their oxidation potentials are correlated with the observed antioxidant activities and oxidation mechanism of alpha-tocopherol. The reductive voltametric behaviour of quinone function in both plastoquinones 3 and 4 is discussed.
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One filler often utilized in flexible polyurethane foams is calcium carbonate (CaCO3) because it is non-abrasiveness, non-toxicity and facilitated pigmentation. However, it is observed that the excess of commercial CaCO3 utilized in industry possibly causing permanent deformations and damaging the quality of the final product. The effect of different concentrations of commercial CaCO3, in flexible foams, was studied. Different concentrations of CaCO3 were used for the synthesis of flexible polyurethane foams, which were submitted to morphological and thermal analyses to verify the alterations provoked by the progressive introduction of this filler.
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Neste trabalho, relatamos o emprego de gibbsita e de uma peneira molecular comercial para a retenção de íons cromo. Os estudos envolveram, além destes materiais, soluções com diferentes concentrações do íon e variações na concentração e na temperatura das soluções e, também, do tempo de contato entre essas e as fases estacionárias. Os resultados desses experimentos e dos posteriores processos de lixiviação do íon indicam que tanto a gibbsita quanto a peneira molecular são materiais que apresentam alta capacidade de retenção deste íon e, além disso, são altamente resistentes aos processos de lixiviação.
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OBJETIVO: Avaliar a preservação da fertilidade e dos ovários em mulheres submetidas à cirurgia por tumor anexial benigno.MÉTODOS: Para este estudo observacional com coleta prospectiva foram incluídas 206 mulheres operadas no CAISM-Unicamp de fevereiro de 2010 a janeiro de 2014. A preservação da fertilidade foi definida como tumorectomia ou anexectomia unilateral sem histerectomia em mulheres na pré-menopausa. A preservação ovariana foi considerada quando pelo menos um ovário ou parte dele foi preservado.RESULTADOS: Das 206 mulheres com tumores anexiais benignos, 120 (58%) estavam na pré-menopausa e 86 (42%) na pós-menopausa. Na pré-menopausa, foram encontrados 36 (30%) tumores de células germinativas, 31 (26%) neoplasias epiteliais e 11 (9%) do cordão sexual e estroma. Na pós-menopausa foram identificados 35 (41%) neoplasias epiteliais, 27 (31%) do cordão sexual e estroma e 8 (9%) de células germinativas. Entre as 36 mulheres com tumores ovarianos não neoplásicos, 21 (58%) apresentavam endometriomas e 8 (22%) cistos funcionais. Das 22 mulheres com tumores extra ovarianos, o leiomioma uterino foi o achado mais frequente (50%). Entre as pacientes com ≤35 anos, 26 (57%) foram submetidas à tumorectomia e 18 (39%) a anexectomia unilateral com preservação do útero e anexo contralateral. Mulheres com ≤35 anos foram mais frequentemente operadas por laparoscopia que esteve associada a maior taxa de preservação de fertilidade quando comparada com a laparotomia (p<0,01). Observou-se que 26 das pacientes submetidas à histerectomia com anexectomia (28%) bilateral estavam na pré-menopausa.CONCLUSÕES: Embora se observe uma tendência em realizar apenas tumorectomia em mulheres com ≤35 anos, uma proporção significativa de mulheres jovens ainda é submetida à anexectomia. Em mulheres entre 36 e 45 anos, apenas dois terços tiveram sua fertilidade preservada e 20% tiveram ambos os ovários removidos. No entanto, deve-se tentar preservar os ovários sempre que possível, sobretudo nas mulheres na pré-menopausa.
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Trombose da veia jugular é problema freqüente na medicina eqüina, implicando muitas vezes em conseqüências fatais. O objetivo deste trabalho foi avaliar em eqüinos a aplicabilidade da trombectomia com cateter de Fogarty, técnica rotineiramente empregada pela medicina humana, no restabelecimento da perviedade vascular. Foram utilizados 10 eqüinos divididos em dois grupos de cinco animais, em que se induziu a trombose da veia jugular direita, através do acesso cirúrgico à veia e aplicação de sutura estenosante e injeção de glicose a 50%. No grupo controle avaliou-se a evolução da tromboflebite sem qualquer tipo de intervenção terapêutica. Os animais do grupo tratado foram submetidos à trombectomia com cateter de Fogarty. Foram avaliados os parâmetros clínicos gerais, regionais, ultra-sonográficos e angiográficos, nos momentos pré-indução (M-PRÉ), indução da trombose (MTI) e 10 dias de evolução da trombose (M10). A técnica empregada induziu a tromboflebite, que obstruiu completamente um segmento da veia jugular de todos os animais. Os animais do grupo controle mantiveram os trombos obstruindo totalmente o lume vascular até o final do período de avaliação, sendo que avaliações regionais mostraram principalmente o edema parotídeo e o ingurgitamento vascular, cranial à tromboflebite da veia jugular. O grupo tratado apresentou as veias jugulares pérvias ao final do experimento, confirmadas pelos exames ultra-sonográficos e angiográficos, com remissão total dos sinais clínicos. Concluiu-se que a técnica da trombectomia com cateter de Fogarty foi eficiente na desobstrução da veia jugular submetida à trombose experimental.
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Hepatitis viruses belong to different families and have in common a striking hepatotropism and restrictions for propagation in cell culture. The transmissibility of hepatitis is in great part limited to non-human primates. Enterically transmitted hepatitis viruses (hepatitis A virus and hepatitis E virus) can induce hepatitis in a number of Old World and New World monkey species, while the host range of non-human primates susceptible to hepatitis viruses transmitted by the parenteral route (hepatitis B virus, hepatitis C virus and hepatitis delta virus) is restricted to few species of Old World monkeys, especially the chimpanzee. Experimental studies on non-human primates have provided an invaluable source of information regarding the biology and pathogenesis of these viruses, and represent a still indispensable tool for vaccine and drug testing.