961 resultados para xylan 1,4 beta xylosidase


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Isoelectric focusing of human urinary metallothionein at a pH range of 4.8 to 7.0 yielded a single protein band with a pI of 5.57 which co-migrated with authentic purified metallothionein I from human liver. Minimum pretreatment of the urine samples (160 ml) was needed. The preparatory steps included sample concentration with the original protein, enriched from 69 +/- 23 micrograms/ml to 2.0 +/- 1.4 mg/ml (+/- SD; n = 9), followed by heat treatment at 80 degrees C for 5 min (2.4 +/- 1.7 mg protein/ml). After focusing, the gels were stained with silver and the lanes were scanned with a laser scanner. Peak areas were used for quantitation with commercial beta 2-microglobulin as a standard. The urinary metallothionein ranged from 1.0 to 2.6 nmol/mmol creatinine, which is comparable with values reached by radio-immunoassay.

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BACKGROUND: Reducing the fraction of transmissions during recent human immunodeficiency virus (HIV) infection is essential for the population-level success of "treatment as prevention". METHODS: A phylogenetic tree was constructed with 19 604 Swiss sequences and 90 994 non-Swiss background sequences. Swiss transmission pairs were identified using 104 combinations of genetic distance (1%-2.5%) and bootstrap (50%-100%) thresholds, to examine the effect of those criteria. Monophyletic pairs were classified as recent or chronic transmission based on the time interval between estimated seroconversion dates. Logistic regression with adjustment for clinical and demographic characteristics was used to identify risk factors associated with transmission during recent or chronic infection. FINDINGS: Seroconversion dates were estimated for 4079 patients on the phylogeny, and comprised between 71 (distance, 1%; bootstrap, 100%) to 378 transmission pairs (distance, 2.5%; bootstrap, 50%). We found that 43.7% (range, 41%-56%) of the transmissions occurred during the first year of infection. Stricter phylogenetic definition of transmission pairs was associated with higher recent-phase transmission fraction. Chronic-phase viral load area under the curve (adjusted odds ratio, 3; 95% confidence interval, 1.64-5.48) and time to antiretroviral therapy (ART) start (adjusted odds ratio 1.4/y; 1.11-1.77) were associated with chronic-phase transmission as opposed to recent transmission. Importantly, at least 14% of the chronic-phase transmission events occurred after the transmitter had interrupted ART. CONCLUSIONS: We demonstrate a high fraction of transmission during recent HIV infection but also chronic transmissions after interruption of ART in Switzerland. Both represent key issues for treatment as prevention and underline the importance of early diagnosis and of early and continuous treatment.

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In this contribution a few new gold(I)phosphine complexes, [2-(PPh2)C6H4CO 2H]AuX (where X = Cl, SCN, Br3) and a similar gold(III) derivative [{2-(PPh2)C6H4CO 2H}AuIII Cl (C6H4CH2NMe2 )]Cl have been synthesised and characterised. The phosphine, 2-(diphenylphosphino)benzoic acid, has been employed for the first time in gold chemistry. This ligand is potentially bidentate through bonding of the phosphine and carboxylate groups. The X-ray structure of the complex chloro[2-(diphenylphosphino) benzoic acid]gold(I) has been elucidated and the bond lengths encountered show great similarity to those of chloro(triphenylphosphine)gold(I). [2-(PPh2)C6H4CO 2H]AuCl crystallises in the space group P2(1)/c with a = 9.113(2) Å, b = 10.925(2) Å, c = 23.069(4) Å, beta = 99.95º(3), V = 2299 ų, Z = 4 and R = 0.091. Biological tests for anti-fungal and anti-bacterial activity demostrate that [2-(PPh2)C6H4CO 2H]AuCl exhibits broad spectrum activity against a range of organisms.

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Phytochemical investigation of the aerial parts and roots of Mucuna cinerea led to the isolation of a mixture of fatty acids, triacylglicerols, beta-sitosterol, stigmasterol, stigmasterol glucoside, daucosterol, asperglaucide (4) and the isoflavonoids prunetin (1), genistein (2), medicarpin (3), daidzein (5), 7-O-alpha-glycopiranosyl daidzein (6). An in vitro bioassay was carried out with compounds 1-4, at the concentration of 50 and 5 mug mL-1 against the phytonematodes M. incognita and H. glycines. Although the four compounds showed some nematocidal property, the most active was (1), causing 70% mortality of M. incognita at the concentration of 50 mug mL-1.

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From the leaves of Bauhinia forficata kaempferol and four flavonoid glycosides, 3,7-di-O-alpha-L-rhamnopyranosylkaempferol, 3,7-di-O-alpha-L-rhamnopyranosylquercetin, 3-O-[alpha-L-rhamnopyranosyl-(1->6)-beta-D-glucopyranosyl]-7-O-alpha-L-rhamnopyranosylkaempferol and 3-O-[alpha-L-rhamnopyranosyl-(1->6)-beta-D-glucopyranosyl]-7-O-alpha-L-rhamnopyranosylquercetin were obtained. From the flowers only the flavonoid 7-O-alpha-L-rhamnopyranosylkaempferol was isolated. The structures were established by chemical and spectroscopic methods.

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We report the synthesis of amino(2-hydroxy-2-(4-methoxyphenyl)ethylamino)methaniminium (14) as a direct precursor of a tubastrine derivative (3-dehydroxy-4-methoxytubastrine). The synthetic steps involved functional group interconversions starting from 1-(4-methoxyphenyl)ethanone to obtain the guanidine-protected derivative 13. Tentative dehydration of 13 with SiOH-adsorbed CuSO4 resulted in guanidine deprotection only. This was an unexpected result, since there are no reports of CuSO4.SiOH as Boc-deprotecting of guanidines. The product 14 was obtained in five steps and 5.4 % overall yield, and constitutes a direct precursor of 3-dehydroxy-4-methoxytubastrine.

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The Copper-catalyzed azide-alkyne cycloaddition (CuAAC), often referred to as "click" reaction, has become a very popular reaction in the last years. It affords exclusively 1,4-disubstituted 1,2,3-triazoles and has been widely used to connect readily accessible building blocks containing various functional groups. The great success of this reaction is based on the fact that it is general, virtually quantitative and very robuste. The scope of this copper-catalyzed synthesis is extraordinary and the reaction has found numerous applications in many research fields, including biological chemistry and materials science. In this review, the main chemical aspects and applications of the "click" reaction in the synthesis of 1,2,3-triazoles are presented.

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Four new compounds with the general formula [Fe(phen)3][Zn(RSO2N=CS2)2], where phen = 1,10-phenanthroline, R = 4-FC6H4 (1), 4-ClC6H4 (2), 4-BrC6H4 (3) and 4-IC6H4 (4), respectively, were obtained by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2N=CS2K2) and tris(1,10-phenanthroline)iron(II) sulfate, with zinc(II) acetate dihydrate in dimethylformamide. The elemental analyses and the IR data were consistent with the formation of the expected complexes salts. The ¹H and 13C NMR spectra showed the signals for the cationic iron(II) complex and dithiocarbimate moieties. The molar conductance data were consistent with the 1:1 cation:anion complexes in 1-4. The antifungal activities of the compounds were tested in vitro against Candida albicans, Candida tropicalis and Colletotrichum gloeosporioides.

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The dehydration kinetic of Yb, Lu and Y 4-chlorobenzylidenepyruvate was studied by using thermogravimetry and the kinetics parameters obtained by Flynn and Wall method suggest that the dehydration step follows a first order mechanism. The activation energies calculated were 103.6, 96.6 and 97.2 kJ/mol and the lifetime considering the temperature of 31 and 101 º C for the dehydration of these compounds were 23, 26, 31 minutes and 0.6, 1.3 and 1.4 seconds, respectively. The results have similar values and suggest that the water is attached in the same way.

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The growth of breast cancer is regulated by hormones and growth factors. Recently, aberrant fibroblast growth factor (FGF) signalling has been strongly implicated in promoting the progression of breast cancer and is thought to have a role in the development of endocrine resistant disease. FGFs mediate their auto- and paracrine signals through binding to FGF receptors 1-4 (FGFR1-4) and their isoforms. Specific targets of FGFs in breast cancer cells and the differential role of FGFRs, however, are poorly described. FGF-8 is expressed at elevated levels in breast cancer, and it has been shown to act as an angiogenic, growth promoting factor in experimental models of breast cancer. Furthermore, it plays an important role in mediating androgen effects in prostate cancer and in some breast cancer cell lines. We aimed to study testosterone (Te) and FGF-8 regulated genes in Shionogi 115 (S115) breast cancer cells, characterise FGF-8 activated intracellular signalling pathways and clarify the role of FGFR1, -2 and -3 in these cells. Thrombospondin-1 (TSP-1), an endogenous inhibitor of angiogenesis, was recognised as a Te and FGF-8 regulated gene. Te repression of TSP-1 was androgen receptor (AR)-dependent. It required de novo protein synthesis, but it was independent of FGF-8 expression. FGF-8, in turn, downregulated TSP-1 transcription by activating the ERK and PI3K pathways, and the effect could be reversed by specific kinase inhibitors. Differential FGFR1-3 action was studied by silencing each receptor by shRNA expression in S115 cells. FGFR1 expression was a prerequisite for the growth of S115 tumours, whereas FGFR2 expression alone was not able to promote tumour growth. High FGFR1 expression led to a growth advantage that was associated with strong ERK activation, increased angiogenesis and reduced apoptosis, and all of these effects could be reversed by an FGFR inhibitor. Taken together, the results of this thesis show that FGF-8 and FGFRs contribute strongly to the regulation of the growth and angiogenesis of experimental breast cancer and support the evidence for FGF-FGFR signalling as one of the major players in breast cancers.

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Soitinnus: orkesteri. - Viimeisessä osassa myös: lauluäänet (mezzosopraano, tenori), sekakuoro.

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Estudos têm demonstrado a utilização de glicoproteínas e hormônios para prognosticar a evolução de uma gravidez complicada por ameaça de abortamento. Entretanto, alguns resultados ainda são duvidosos. Portanto, o objetivo deste estudo foi avaliar as dosagens de CA-125, CA-19.9, CA-15.3, beta-hCG, estradiol, progesterona, alfa-fetoproteína e antígeno cárcino-embrionário no sangue periférico de mulheres com abortamento inevitável (n=18) e com ameaça de abortamento que posteriormente evoluíram para o abortamento (n=6) no prazo de 1 a 26 dias. O grupo controle foi constituído de mulheres grávidas normais com idade gestacional semelhante (n=7). Todas as pacientes foram atendidas no Hospital Escola e/ou Ambulatório de Ginecologia e Obstetrícia da Faculdade de Medicina do Triângulo Mineiro. Os resultados demonstraram que as dosagens de CA-125 nos grupos controle, abortamento inevitável e ameaça de abortamento foram, respectivamente: 24,7 ± 13,4 UI/ml; 153,9 ± 43,3 UI/ml e 17,4 ± 2,6 UI/ml sendo estatisticamente significante a diferença entre o grupo com abortamento inevitável em comparação com os outros grupos. A dosagem de CA-19.9 foi significantemente menor no grupo com abortamento inevitável em relação ao grupo com ameaça de abortamento (6,6 ± 1,4 UI/ml versus 20,2 ± 11,4 UI/ml). A dosagem de estradiol foi significantemente menor no grupo com abortamento inevitável em comparação com o grupo controle (1.327 ± 1.015 ng/ml versus 10.774 ± 9.244 ng/ml). As pacientes com ameaça de abortamento e com abortamento inevitável apresentaram níveis mais baixos de progesterona que o grupo controle, respectivamente: 17,38 ± 9,4 ng/ml; 18,3 ± 8,9 ng/ml e 60,4 ± 26,8 ng/ml. Concluímos que as dosagens de progesterona, CA-19.9 e do beta-hCG podem servir como prognóstico de evolução de uma gravidez inicial complicada com ameaça de abortamento.

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Foi realizado estudo longitudinal em 42 pacientes com diagnóstico de gravidez ectópica íntegra, com o intuito de se elaborar um índice orientador do uso sistêmico de metotrexato em dose única (50 mg/m²) por via intramuscular. O acompanhamento se fez através de dosagens de beta-hCG (fração beta do hormônio gonadotrópico coriônico) realizadas no 1º, 4º e 7º dias após o emprego do quimioterápico. Quando ocorreu queda de 15% ou mais nos títulos de beta-hCG, apurados no 4º e no 7º dia, as pacientes receberam alta hospitalar e seguimento ambulatorial com dosagens semanais de beta-hCG até que se atingissem níveis inferiores a 5 mUI/ml. Foi elaborado um índice orientador do tratamento sistêmico com metotrexato baseado nos seguintes parâmetros: (1) valores iniciais de beta-hCG; (2) aspecto da imagem à ultra-sonografia (hematossalpinge, anel tubário, embrião vivo); (3) maior diâmetro da massa anexial; (4) quantidade de líquido livre; (5) fluxo vascular medido por meio do doppler colorido. Cada parâmetro recebeu pontuação de 0 a 2. A nota zero significa elemento de mau prognóstico, a nota dois indica parâmetros favoráveis e a nota um, situações intermediárias. O índice de sucesso com dose única foi de 69,0% (29/42 pacientes). A ultra-sonografia transvaginal com doppler colorido foi realizada em 20 das 42 pacientes do estudo. Neste grupo de 20 pacientes o sucesso do tratamento ocorreu em 75,0% dos casos (15/20). Entre as 22 pacientes que não foram avaliadas com doppler colorido a média das notas do índice nos casos de sucesso foi de 6,6, nas de insucesso 3,1. No grupo de pacientes avaliadas por doppler (20 pacientes) as médias foram de 7,9 (sucesso) e 4,2 (fracasso). No presente estudo a nota de corte foi estabelecida levando-se em conta o valor abaixo do qual o tratamento não foi efetivo e correspondeu a cinco, pois 93,75% das pacientes com nota superior a 5 evoluíram com sucesso (15/16), ao passo que notas inferiores ou iguais a cinco estiveram todas relacionadas com o fracasso do tratamento. O índice orientador ajuda-nos a indicar os melhores casos para o tratamento medicamentoso. Não o aconselhamos, portanto, quando a nota for inferior ou igual a cinco; por outro lado, podemos predizer boa evolução do tratamento, quando a nota for superior a cinco.