14 research outputs found

    Novel 3,3-disubstituted oxindole derivatives. Synthesis and evaluation of the anti-proliferative activity

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    3,3-Disubstituted oxindole derivatives bearing a nitrogen atom at the C-3 position have been synthesized starting from 3-alkyl oxindole through a metal free pathway. These derivatives have been tested in five human tumor cell lines (PC3, MCF7, SW620, MiaPaca2 and A375) and on primary cells (PBMCs) from healthy donors providing compound 6d showing a strong anticancer effect in all cancer lines on the low micromolar range

    A new method for the synthesis of carba-sugar enones (gabosines) using a mercury(II)-mediated opening of 4,5-cyclopropanated pyranosides as the key-step

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    The stereoselective transformation of the cyclopropyl derivative 2, stereoselectively obtained with the Simmons–Smith reaction of methyl 2,6-di-O-benzyl-alfa-L-threo-hex-4-enopyranoside (1), into gabosines and deoxy-carbahexoses is described. The treatment of 2 with mercuric trifluoroacetate in dry methanol gives the organomercuric chloride 3, which by demercuration with lithium aluminum hydride affords the 4-C-deoxy-4-methyl-1,5-bis-glycoside 4. The acid hydrolysis of 4 produces a mixture of the two diastereoisomeric 2-methyl-cyclohex-2-enones 6 and 7, catalytically reduced to carba-sugars 10 and 11. Structures and stereochemistry of all isolated compounds were determined by 1D and 2D NMR experiments

    Copper(II)-catalyzed alkoxyhalogenation of alkynyl ureas and amides as a route to haloalkylidene substituted heterocycles

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    A highly effective synthesis of haloalkylidene-substituted heterocycles by copper(II)-catalyzed cyclization of alkynyl ureas and secondary amides has been developed. The reaction, which involves a catalytic amount of CuCl2 and a stoichiometric amount of N-halosuccinimide, occurs selectively through an alkoxyhalogenation process. Alternatively, alkoxychlorination and alkoxybromination reactions can be performed working solely with stoichiometric CuCl, and CuBr2, respectively

    Computational Mechanistic Study of Thionation of Carbonyl Compounds with Lawesson's Reagent

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    The thionation reaction of carbonyl compounds with Lawesson’s reagent (LR) has been studied using density functional theory methods and topological analyses. After dissociation of LR, the reaction takes place through a twostep mechanism involving (i) a concerted cycloaddition between one monomer and the carbonyl compound to form a four-membered intermediate and (ii) a cycloreversion leading to the thiocarbonyl derivative and phenyl(thioxo)phosphine oxide. Topological analyses confirmed the concertedness and asynchronicity of the process. The second step is the rate-limiting one, and the whole process resembles the currently accepted mechanism for the lithium salt-free Wittig reaction. No zwitterionic intermediates are formed during the reaction, although stabilizing electrostatic interactions are present in initial stages. Phenyl(thioxo)phosphine oxide formed in the thionation reaction is capable of performing a second thionation, although with energy barriers higher than the first one. The driving force of the thionation reactions is the formation of trimers from the resulting monomers. In agreement with experimental observations, the amides are the most reactive when compared with esters, aldehydes, and ketones and the reaction is slightly influenced by the polarity of the solvent. Whereas for amides and esters substituents have little effect, aldehydes and ketones are influenced by both steric and electronic effects

    Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails: A Review

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    Nail plate brittleness (or fragility) is a common complaint affecting up to 20% of the population, especially women over 50 years of age, with fingernail fragility being more prevalent than toenail fragility. Nail brittleness is characterized by nails that split, flake and crumble, become soft and lose elasticity. The main clinical presentations are: onychoschizia, onychorrhexis, superficial granulation of keratin and worn-down nails. According to causative factors, we can distinguish 2 forms of nail fragility (NF): a primary \u201cidiopathic or brittle nail syndrome\u201d form and NF secondary to different causes such as inflammatory nail disorders, infections, systemic diseases and general conditions, traumas and alteration of the nail hydration. Optimal management requires treatment of the primary cause of brittle nails, when possible. In idiopathic NF oral supplementation, vitamins (especially biotin, also known as vitamin B7), trace elements and amino acids (especially cysteine) have been reported to be useful. In addition, several products, such as topical moisturizers and lacquers could be considered to restructure the affected nail plate and to reduce psychological impacts of this common problem

    Increased mortality after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis and low ejection fraction: a meta-analysis of 6898 patients

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    BACKGROUND: There is conflicting evidence regarding the safety and efficacy of transcatheter aortic valve implantation (TAVI) procedures in patients with severe aortic stenosis and low left ventricular ejection fraction (EF). The primary aim of this study was to determine the impact of TAVI on short- and long-term mortality in patients with low EF (EF <50%); the secondary aim was to analyze the impact of TAVI procedure on EF recovery in the same setting of patients. METHODS AND RESULTS: Twenty-six studies enrolling 6898 patients with severe aortic stenosis undergoing TAVI procedure were included in the meta-analysis and analyzed for 30-day, 6-month and 1-year all-cause and cardiovascular mortality; a further meta-analysis was also performed in patients with low EF to assess EF changes post TAVI. In low EF patients, both all-cause and cardiovascular short- and long-term mortality were significantly higher when compared to patients with normal EF (30-day-all-cause mortality: 0.13; 95% confidence interval [CI]: 0.01 to 0.25, I(2)=49.65, Q=21.85; 1-year-all-cause mortality: 0.25; 95% [CI]: 0.16 to 0.34, I(2)=25.57, Q=16.12; 30-day-cardiovascular mortality: 0.03; 95% [CI]: -0.31 to 0.36, I(2)=66.84, Q=6.03; 1-year-cardiovascular mortality: 0.29; 95% [CI]: 0.12 to 0.45, I(2)=0.00, Q=1.88). Nevertheless, in low EF patients TAVI was associated with a significant recovery of EF, which started at discharge and proceeded up to 1-year-follow-up. CONCLUSIONS: Patients with low EF severe aortic stenosis have higher mortality following TAVI compared to normal EF patients, despite a significant and sustained improvement in EF

    Increased mortality after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis and low ejection fraction: a meta-analysis of 6898 patients

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    BACKGROUND: There is conflicting evidence regarding the safety and efficacy of transcatheter aortic valve implantation (TAVI) procedures in patients with severe aortic stenosis and low left ventricular ejection fraction (EF). The primary aim of this study was to determine the impact of TAVI on short- and long-term mortality in patients with low EF (EF <50%); the secondary aim was to analyze the impact of TAVI procedure on EF recovery in the same setting of patients. METHODS AND RESULTS: Twenty-six studies enrolling 6898 patients with severe aortic stenosis undergoing TAVI procedure were included in the meta-analysis and analyzed for 30-day, 6-month and 1-year all-cause and cardiovascular mortality; a further meta-analysis was also performed in patients with low EF to assess EF changes post TAVI. In low EF patients, both all-cause and cardiovascular short- and long-term mortality were significantly higher when compared to patients with normal EF (30-day-all-cause mortality: 0.13; 95% confidence interval [CI]: 0.01 to 0.25, I(2)=49.65, Q=21.85; 1-year-all-cause mortality: 0.25; 95% [CI]: 0.16 to 0.34, I(2)=25.57, Q=16.12; 30-day-cardiovascular mortality: 0.03; 95% [CI]: -0.31 to 0.36, I(2)=66.84, Q=6.03; 1-year-cardiovascular mortality: 0.29; 95% [CI]: 0.12 to 0.45, I(2)=0.00, Q=1.88). Nevertheless, in low EF patients TAVI was associated with a significant recovery of EF, which started at discharge and proceeded up to 1-year-follow-up. CONCLUSIONS: Patients with low EF severe aortic stenosis have higher mortality following TAVI compared to normal EF patients, despite a significant and sustained improvement in EF

    Influência da suplementação de vitamina E na profilaxia e tratamento da broncopneumonia moderada e grave em bezerros

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    Estudou-se a broncopneumonia de ocorrência natural em bezerros e a influência da administração de acetato de DL-α-tocoferol na profilaxia e tratamento desta enfermidade. Foram avaliados 60 bezerros machos, com idade máxima de 10 dias, divididos em dois grupos experimentais: GSV (grupo sem vitamina) e GCV (grupo com vitamina). A suplementação com dose única de 4.500 UI de acetato de DL-α-tocoferol por via intramuscular (IM) foi precedida por exame físico, perfil hematológico, determinação de proteínas séricas, globulinas, gamaglutamiltransferase e citologia do lavado traqueobrônquico (D0) para verificar a sanidade e homogeinização dos grupos. Os bezerros foram mantidos em bezerreiro e distribuídos aleatoriamente, 2 a 2 em baias individuais de 2,40m², onde permaneceram até o 21º dia (D0 ao D21). Foram avaliados por exame físico diário e, na presença de sinais clínicos indicativos de broncopneumonia (DX), retirados do bezerreiro, avaliados por hemograma e citologia do lavado traqueobrônquico, e tratados com enrofloxacina (5mg/kg, IM). Durante o tratamento, o exame físico foi realizado diariamente, e o hemograma e a citologia do lavado traqueobrônquico repetidos uma semana após seu término (DY). Nos bezerros sadios foram repetidos hemograma e citologia do lavado traqueobrônquico, no último dia (D21) do experimento. Não houve diferença significativa quanto às variáveis gamaglutamiltrasfrase (p=0,09), proteínas séricas (p=0,27) e globulinas (p=0,10) e a idade dos bezerros (p=0,15) entre os grupos. Os bezerros do grupo GSV e GCV levaram em média 11 e 12 dias para adoecerem, respectivamente. Contudo, não houve diferença estatística significativa entre os grupos (p=0,68). Em 34 bezerros (56,66%) foi diagnosticado broncopneumonia, sendo que 17 destes bezerros (50%) pertenciam ao grupo GCV e 17 (50%) ao grupo GSV. Com relação aos sinais clínicos, não houve diferença significativa entre os grupos em nenhum dos momentos estudados. Dos 34 bezerros que adoeceram 73,52% morreram pela doença, sendo 64,7% do GCV e 82,35% do GSV. A citologia do lavado traqueobrônquico não apresentou diferença significativa entre os grupos em nenhum dos momentos estudados (D0, DX, DY e D21). A suplementação com vitamina E não teve influência na profilaxia e no tratamento de broncopneumonia de bezerros
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