255 research outputs found

    Synthesis of 2-methyl- and 2-methylenecyclobutane amino acids

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    An efficient and easy formal [2+2] cycloaddition (Michael-Dieckmann-type reaction) on methyl 2-acetamidoacrylate with ketene diethyl acetal gave the cyclobutane core. Two kinds of 2-substituted cyclobutane amino acids have been obtained from this compound by means of stereocontrolled interconversion of functional groups: 1-amino-2-methylcyclobutane-1-carboxylic acids (2,4-methanovalines) and 1-amino-2-methylenecyclobutane-1-carboxylic acid. The latter amino acid can be regarded as a restricted -methyl-- vinylglycine. © 2005 Elsevier Ltd. All rights reserved

    Systematic review and meta-analysis of the pharmacokinetics of benznidazole in the treatment of Chagas disease

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    Chagas disease is a neglected parasitic illness affecting approximately 8 million people, predominantly in Latin America. Benznidazole is the drug of choice for treatment, although its availability has been limited. A paucity of knowledge of the pharmacokinetic properties of this drug has contributed to its limited availability in several jurisdictions. The objective of this study was to conduct a systematic literature review and a Bayesian meta-analysis of pharmacokinetic studies to improve estimates of the basic pharmacokinetic properties of benznidazole. A systematic search of the Embase, Medline, LILACS, and SciELO (Scientific Electronic Library Online) databases was conducted. Eligible studies reported patient-level data from single-100-mg-dose pharmacokinetic evaluations of benznidazole in adults or otherwise provided data relevant to the estimation of pharmacokinetic parameters which could be derived from such studies. A Bayesian hierarchical model was used for analysis. Secondary data (i.e., data from studies that did not include patient-level, single-100-mg-dose data) were used for the generation of empirical priors for the Bayesian analysis. The systematic search identified nine studies for inclusion. Nine pharmacokinetic parameters were estimated, including the area under the concentration-time curve (AUC), the maximum concentration of drug in plasma (Cmax), the time to Cmax, the elimination rate constant (kel), the absorption rate constant (Ka), the absorption and elimination half-lives, the apparent oral clearance, and the apparent oral volume of distribution. The results showed consistency across studies. AUC and Cmax were 51.31 mg · h/liter (95% credible interval [CrI], 45.01, 60.28 mg · h/liter) and 2.19 mg/liter (95% CrI, 2.06, 2.33 mg/liter), respectively. Ka and kel were 1.16 h-1 (95% CrI, 0.59, 1.76 h-1) and 0.052 h-1 (95% CrI, 0.045, 0.059 h-1), respectively, with the corresponding absorption and elimination half-lives being 0.60 h (95% CrI, 0.38, 1.11 h) and 13.27 h (95% CrI, 11.79, 15.42 h), respectively. The oral clearance and volume of distribution were 2.04 liters/h (95% CrI, 1.77, 2.32 liters/h) and 39.19 liters (95% CrI, 36.58, 42.17 liters), respectively. A Bayesian meta-analysis was used to improve the estimates of the standard pharmacokinetic parameters of benznidazole. These data can inform clinicians and policy makers as access to this drug increases.Fil: Wiens, Matthew O.. University of British Columbia; CanadáFil: Kanters, Steve. Precision Global Health;Fil: Mills, Edward. Mc Master University; CanadáFil: Peregrina Lucano, Alejandro A.. Universidad de Guadalajara; MéxicoFil: Gold, Silvia. Fundación Mundo Sano; ArgentinaFil: Ayers, Dieter. Precision Global Health;Fil: Ferrero, Luis. Fundación Mundo Sano; ArgentinaFil: Krolewiecki, Alejandro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; Argentin

    Conformationally-Locked C-Glycosides: Tuning Aglycone Interactions for Optimal Cheperone Behaviour in Gaucher Fibroblasts

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    A series of conformationally locked C-glycosides based on the 3-aminopyrano[3,2-b]pyrrol-2(1H)-one (APP) scaffold has been synthesized. The key step involved a totally stereocontrolled C-Michael addition of a serine-equivalent C-nucleophile to tri-O-benzyl-2-nitro-D-galactal, previously published by the authors. Stereoselective transformations of the Michael adduct allowed us the synthesis of compounds with mono- or diantennated aglycone moieties and different topologies. In vitro screening showed highly selective inhibition of bovine liver β-glucosidase/β-galactosidase and specific inhibition of human β-glucocerebrosidase among lysosomal glycosidases for compounds bearing palmitoyl chains in the aglycone, with a marked dependence of the inhibition potency upon their number and location. Molecular dynamics simulations highlighted the paramount importance of an optimal orientation of the hydrophobic substituent to warrant efficient non-glycone interactions, which are critical for the binding affinity. The results provide a rationale for the strong decrease of the inhibition potency of APP compounds on going from neutral to acidic pH. The best candidate was found to behave as pharmacological chaperone in Gaucher fibroblasts with homozygous N370S and F213I mutations, with enzyme activity enhancements similar to those encountered for the reference compound AmbroxolMinisterio de Economía y Competitividad CTQ2012-36365, SAF2013-44021-RJunta de Andalucía FQM-1467European Union Seventh Framework Programme FP7-People-2012-CI

    Vástagos cementados y no cementados en artroplastias totales de cadera por coxopatías mecánicas

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    En la controversia sobre la cementación o no del componente femoral se presenta el análisis clínico, radiológico y de supervivencia de los vástagos de una serie de 121 artoplastias totales de cadera (61 cementadas y 60 sin cementar). El estudio no evidencia diferencias significativas a los 5 años de seguimiento, aunque es destacable una mayor incidencia de dolor en el muslo entre los vástagos no cementados (35%) (p < 0,1) y una tasa de reabsorción ósea proximal más elevada (70%) que en los cementados (23%). Estos fenómenos son diseño dependientes. Un mayor número de cirugías de revisión por aflojamiento aséptico entre las prótesis cementadas nos hacen preferir la fijación sin cemento del componente femoral.We discuss the cemented or non-cement fixation of the femoral components in total hip arthroplasty on a serie of 121 femoral stem (61 cemented stem and 60 non-cemented stem). Survival analysis, clinical and radiographic data showed no significant differences between the two groups at 5 years follow-up. However the incidence of pain thigh phenomenon was higher for the non-cemented stem (35%) (p < 0.1). Stress schielding was evidently higher between the non-cemented implants (70%) too, as compared with cemented stem (23%). These findings are design-dependent. The cemented arthroplasties had a higher rate of revision procedures because of aseptic loosening (13%). In this way we prefer the non-cement fixation of the femoral implant

    Fracturas de húmero complicadas con lesión arterial

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    Presentamos una serie de 10 pacientes afectos de una fractura de húmero asociada a una lesión arterial, tratados entre Enero de 1990 y Octubre de 1993. Dentro de la serie distinguimos tres grupos, de acuerdo con la localización de la fractura (tercio proximal, diáfisis, región supracondílea). El análisis de los resultados sugiere que el peor pronóstico corresponde a las lesiones proximales y diafisarias por su etiología, daños asociados y menor posibilidad de circulación colateral de suplencia. El manejo de estas lesiones complejas exige un tratamiento quirúrgico interdisciplinario. Señalamos la utilidad de la fijación externa como método de osteosíntesis y el uso de un «shunt» provisional para perfundir el miembro durante la cirugía ósea. Se discute la indicación de arteriografía en los traumatismos agudos del miembro superior.A serie of 10 patients with a fracture of the humerus and associated arterial injury treated from January 1990 to October 1993 is reported. The serie was divided in 3 groups acording the proximal, mid shaft or supracondylar location of the fracture. Clinical results indicate a poor prognosis of proximal and mid shaft fractures related to their etiology, associated injuries and damage of the colateral vessels. The management of these complex injuries require an interdisciplinar approach. External fixation is an usefull stabilitation method for fractures associated with vascular damage. The utility of a temporary intraluminar vascular shunt to perfuse the limb at the bone surgery and preoperative arteriography are discussed

    MUC1 glycopeptides incorporating Tn antigen mimetics

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    Jalisco : construcción de un imaginario

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    Jalisco de ha constituido en el estado emblemático de la mexicanidad, por encima del resto de las entidades que conforman los Estados Unidos Mexicanos. Tal imagen se ha construido principalmente en torno del mariachi, los charros y el tequila, elementos populares que tuvieron su origen en zonas rurales, sin que esto haya sido obstáculo para la formación de un imaginario cultural unitario, que se ha proyectado tanto en el plano nacional como en el internacional. El propósito principal de Jalisco: construcción de un imaginario es dilucidar vicisitudes que han contribuido a que Jalisco ocupe ese lugar. Los capítulos que lo conforman se ocupan de este proceso desde distintos puntos de vista, que abarcan la historia, cultura, religión comercio, urbanismo, migración etcétera, con la intención de contribuir a confirmar o desmentir que en Jalisco se resume el alma nacional

    Aortic Sinus Contrast Retention During TAVR : A Warning Sign Preceding a Potential Thrombotic Complication

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    Sinus contrast material retention after transcatheter aortic valve replacement (TAVR) is a rare phenomenon that may reflect an increased risk for thrombotic complications. We present 3 cases of persistent contrast agent retention in the sinus of Valsalva during the TAVR procedure that portend the occurrence of embolic stroke or bioprosthetic valve thrombosis. (Level of Difficulty: Advanced.

    CDH1 somatic alterations in Mexican patients with diffuse and mixed sporadic gastric cancer

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    Background: Diffuse gastric cancer (DGC) is associated with the reduction or absence of the expression of the cell adhesion protein E-cadherin (encoded by the CDH1 gene). Molecular characteristics are less well described for mixed gastric cancer (MGC). The main somatic alterations that have been described in the CDH1 gene are mutations, loss of heterozygosity (LOH) and promoter methylation. The aim was to analyze CDH1 somatic alterations in Mexican patients with diffuse and mixed gastric cancer. Methods: We searched for mutations in the CDH1 gene in tumor DNA from DGC (n = 13) and MGC (n = 7) patients by next generation sequencing (NGS). Validation of findings was performed using Sanger sequencing. LOH was analyzed using dinucleotide repeat markers surrounding the CDH1 gene, and methylation was investigated by DNA bisulfite conversion and sequencing. E-cadherin protein deficiency was analyzed by immunohistochemistry. Results: Seventeen point variants were identified by NGS, 13 of them were validated by Sanger sequencing. Only 1/13 had not been previously reported (c.-137C > A), and 12/13 were already reported as polymorphisms. Two DGC cases presented LOH at the locus 16q22.1 (13.3%). CDH1 promoter methylation was positive in (7/11) 63.6% and (4/6) 66.6% of the cases with DGC and MGC, respectively. E-cadherin protein deficiency was observed in 58.3% of DGC cases while 100% in MGC cases. Conclusions: While no pathogenic somatic mutations were found that could explain the diffuse histology of gastric cancer in DGC and MGC, methylation was the most common somatic inactivation event of the CDH1 gene, and LOH was rare. The previously unreported c.-137C > A variant modify the CDH1 gene expression since it alters the binding sites for transcription factors.This work was supported by the “Consejo Nacional de Ciencia y Tecnología (CONACYT)” (grant Ciencia Básica 2013–1-222972) and by the “Fondo de Investigación en Salud (FIS), Instituto Mexicano del Seguro Social (IMSS)” (grant FIS/IMSS/PROT/G13/1189), that contributed to the design of the study, collection, analysis, interpretation of data and writing the manuscript. We thank the following institutions: 1) Coordinación de Investigación en Salud (CIS), Instituto Mexicano del Seguro Social (IMSS) for the support given to ARBC, through the Professional Development in the International Research of Graduate Students (PRODESI) program; 2) Fundación IMSS, A.C. for the research grant awarded to JYSL and MTMT; 3) FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT/ Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274); 4) The project NORTE-01-0145-FEDER-000029, supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); 5) FCT fellowships (SFRH/BPD/86543/2012 to JC; SFRH/BPD/89764/2012 to PO; PD/ BD/128007/2016 to AS). IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT, the Portuguese Foundation for Science and Technology

    Evaluation of Physicochemical and Microbial Properties of Extracts from Wine Lees Waste of Matelica’s Verdicchio and Their Applications in Novel Cosmetic Products

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    Wine lees are sediments deposited on the walls and bottom of barrels resulting from wine fermentation and mainly consist of yeasts. Saccharomyces cerevisiae extracts, rich in beneficial components for the skin, have already been used in cosmesis, while wine lees have not been well exploited by the cosmetics industry yet. The aim of this work was the full characterization of the wine lees from Verdicchio's wine, with the aim to exploit it as a beneficial ingredient in new cosmetic products. After mapping the microbial composition of the sample waste, the parameters for the sonication extraction process were optimized and the physicochemical properties of the extract were analyzed. The efficiency of the aqueous extraction-and in particular the yeast cell lysis necessary for the release of proteins from the cell-was assessed by evaluating cell shape and size, and protein release, under scanning electron microscopy (SEM), dynamic light scattering (DLS) and Bradford's protein assays. Thus, the total phenol content and antioxidant capacity of the supernatant recovered from native and sonicated lees were determined by Folin-Ciocalteu's and spectrophotometric assays, respectively. To quantify the heavy metals and highlight the presence of microelements beneficial for the skin, inductively coupled plasma-mass spectrometry (ICP-MS) was applied. In vitro metabolic activity and cytotoxicity were tested on both HaCat keratinocytes and human gingival fibroblasts, showing that wine lees are safe for skin's cells. The results show that sonicated lees appear to be more interesting than native ones as a consequence of the release of the active ingredients from the cells. Due to the high antioxidant capacity, content of beneficial elements for skin and an appropriate microbiologic profile, wine lees were included in five new solid cosmetic products and tested for challenge test, compatibility with human skin, sensory analysis, trans epidermal water loss (TEWL) and sebometry
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