53 research outputs found

    Corrosion assessment and enhanced biocompatibility analysis of biodegradable magnesium-based alloys

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    Magnesium alloys have raised immense interest to many researchers because of its evolution as a new third generation material. Due to their biocompatibility, density, and mechanical properties, magnesium alloys are frequently reported as prospective biodegradable implant materials. Moreover, magnesium based alloys experience a natural phenomena to biodegrade in aqueous solutions due to its corrosive activity, which is excellent for orthopedic and cardiovascular applications. However, major concerns with such alloys are fast and non-uniform corrosion degradation. Controlling the degradation rate in the physiological environment determines the success of an implant. In this investigation, three grades of magnesium alloys: AZ31B, AZ91E and ZK60A were studied for their corrosion resistance and biocompatibility. Scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy and contact angle meter are used to study surface morphology, chemistry, roughness and wettability, respectively. Additionally, the cytotoxicity of the leached metal ions was evaluated by a tetrazolium based bio-assay, MTS

    Plant characterization of genetically modified maize hybrids MON-89Ø34-3 × MON-88Ø17-3, MON-89Ø34-3 × MON-ØØ6Ø3-6, and MON-ØØ6Ø3-6: alternatives for maize production in Mexico

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    Environmental risk assessment (ERA) of genetically modified (GM) crops is a process to evaluate whether the biotechnology trait(s) in a GM crop may result in increased pest potential or harm to the environment. In this analysis, two GM insect-resistant (IR) herbicide-tolerant maize hybrids (MON-89Ø34-3 9 MON-88Ø17-3 and MON-89Ø34-3 9 MON-ØØ6Ø3-6) and one herbicide-tolerant GM hybrid (MON-ØØ6Ø3-6) were compared with conventional maize hybrids of similar genetic backgrounds. Two sets of studies, Experimental Phase and Pilot Phase, were conducted across five ecological regions (ecoregions) in Mexico during 2009–2013, and data were subject to meta-analysis. Results from the Experimental Phase studies, which were used for ERA, indicated that the three GM hybrids were not different from conventional maize for early stand count, days-tosilking, days-to-anthesis, root lodging, stalk lodging, or final stand count. Statistically significant differences were observed for seedling vigor, ear height, plant height, grain moisture, and grain yield, particularly in the IR hybrids; however, none of these phenotypic differences are expected to contribute to a biological or ecological change that would result in an increased pest potential or ecological risk when cultivating these GM hybrids. Overall, results from the Experimental Phase studies are consistent with those from other world regions, confirming that there are no additional risks compared to conventional maize. Results from Pilot Phase studies indicated that, compared to conventional maize hybrids, no differences were detected for the agronomic and phenotypic characteristics measured on the three GM maize hybrids, with the exception of grain moisture and grain yield in the IR hybrids. Since MON-89Ø34- 3 9 MON-88Ø17-3 and MON-89Ø34-3 9 MONØØ6Ø3- 6 confer resistance to target insect pests, they are an alternative for farmers in Mexico to protect the crop from insect damage. Additionally, the herbicide tolerance conferred by all three GM hybrids enables more cost-effective weed management

    CSL–MAML-dependent Notch1 signaling controls T lineage–specific IL-7Rα gene expression in early human thymopoiesis and leukemia

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    Notch1 activation is essential for T-lineage specification of lymphomyeloid progenitors seeding the thymus. Progression along the T cell lineage further requires cooperative signaling provided by the interleukin 7 receptor (IL-7R), but the molecular mechanisms responsible for the dynamic and lineage-specific regulation of IL-7R during thymopoiesis are unknown. We show that active Notch1 binds to a conserved CSL-binding site in the human IL7R gene promoter and critically regulates IL7R transcription and IL-7R α chain (IL-7Rα) expression via the CSL–MAML complex. Defective Notch1 signaling selectively impaired IL-7Rα expression in T-lineage cells, but not B-lineage cells, and resulted in a compromised expansion of early human developing thymocytes, which was rescued upon ectopic IL-7Rα expression. The pathological implications of these findings are demonstrated by the regulation of IL-7Rα expression downstream of Notch1 in T cell leukemias. Thus, Notch1 controls early T cell development, in part by regulating the stage- and lineage-specific expression of IL-7Rα

    Novel genes and sex differences in COVID-19 severity

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    [EN] Here, we describe the results of a genome-wide study conducted in 11 939 coronavirus disease 2019 (COVID-19) positive cases with an extensive clinical information that were recruited from 34 hospitals across Spain (SCOURGE consortium). In sex-disaggregated genome-wide association studies for COVID-19 hospitalization, genome-wide significance (P < 5 × 10−8) was crossed for variants in 3p21.31 and 21q22.11 loci only among males (P = 1.3 × 10−22 and P = 8.1 × 10−12, respectively), and for variants in 9q21.32 near TLE1 only among females (P = 4.4 × 10−8). In a second phase, results were combined with an independent Spanish cohort (1598 COVID-19 cases and 1068 population controls), revealing in the overall analysis two novel risk loci in 9p13.3 and 19q13.12, with fine-mapping prioritized variants functionally associated with AQP3 (P = 2.7 × 10−8) and ARHGAP33 (P = 1.3 × 10−8), respectively. The meta-analysis of both phases with four European studies stratified by sex from the Host Genetics Initiative (HGI) confirmed the association of the 3p21.31 and 21q22.11 loci predominantly in males and replicated a recently reported variant in 11p13 (ELF5, P = 4.1 × 10−8). Six of the COVID-19 HGI discovered loci were replicated and an HGI-based genetic risk score predicted the severity strata in SCOURGE. We also found more SNP-heritability and larger heritability differences by age (<60 or ≥60 years) among males than among females. Parallel genome-wide screening of inbreeding depression in SCOURGE also showed an effect of homozygosity in COVID-19 hospitalization and severity and this effect was stronger among older males. In summary, new candidate genes for COVID-19 severity and evidence supporting genetic disparities among sexes are provided.S

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Epidemiological Factors in Patients with Endometrial Adenocarcinoma

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    Background: endometrial cancer is the most common gynecologic neoplasia and accounts for between 6 to 13 % of all cancers in women. Therefore, it becomes highly important to take into account the epidemiological factors related to endometrial cancer. Objective: to describe some of the epidemiological factors that appears in patients with endometrial adenocarcinoma. Method: an observational, retrospective and descriptive study of all patients treated at the "Enrique Cabrera" General Teaching Hospital with the diagnosis of endometrial cancer, n = 32, from January 1st, 2009 to December 1st, 2010 was conducted. Results: 68,7 % of patients were 60 years old or more, 50 % of them had 1 or 2 children, 75 % had their menarche before the age of 13 and 68,7 % began their menopause with 50 years old or more. As for chronic diseases, 75 % suffered from hypertension and 25 % from diabetes mellitus and ischemic heart disease. Conclusion: it is necessary to conduct a larger study including other risk factors in order to assess the true epidemiological factors of endometrial cancer that are present in our population

    Factores epidemiológicos en pacientes con adenocarcinoma de endometrio

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    Fundamento: el cáncer de endometrio es la neoplasia ginecológica más común y representa entre el 6 y el 13 % de todos los cánceres que se presentan en la mujer, de ahí la importancia de tener en cuenta los factores epidemiológicos relacionados con él. Objetivo: describir algunos de los factores epidemiológicos presentes en pacientes con adenocarcinoma de endometrio. Método: se realizó un estudio observacional, descriptivo, retrospectivo de todas las pacientes atendidas en el Hospital General Docente “Enrique Cabrera” con el diagnóstico de cáncer de endometrio, n= 32, del 1 de/enero/2009 al 31/diciembre/2010. Resultados: 68,7 % de las pacientes tenían 60 años o más, 50 % tenían 1 o 2 hijos, 75 % tuvo su menarquía antes de 13 años y 68,7 % llegaron a la menopausia con 50 o más años. En cuanto a patologías crónicas, 75 % padecían de hipertensión arterial y 25 % de diabetes mellitus y cardiopatía isquémica. Conclusión: se hace necesario un estudio mayor, que incluya otros factores de riesgo, para valorar los verdaderos factores epidemiológicos de cáncer de endometrio, presentes en nuestra población

    Primary Carcinoma in the Fallopian Tube: A Two Cases Report

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    Primary carcinoma in the fallopian tube is a rare gynecological tumor. Its preoperative diagnosis is difficult because of its insidious and silent course. It is usually performed in the postoperative stage. This carcinoma is most frequently presented in post menopausal women. Its clinical and histological behavior is often similar to that of an ovarian cancer. In literature there are reports on the association between ovarian and endometrial cancer. Nevertheless, there are but few references to their association with fallopian tubes cancer. Two cases of primary cancer in the fallopian tubes, diagnosed in a 6 months period through post-surgical histology, that were treated in the Gynecology Service of the ¨Enrique Cabrera¨ General Teaching Hospital are presented. Their preoperative diagnoses were endometrial adenocarcinoma and ovarian cancer. It is relevant that one patient, with 44 years old, was diagnosed through endometrial biopsy performed to remove an intra uterine device. The result of that study was an endometrial adenocarcinoma that required surgery

    Carcinoma primario de la trompa de Falopio: presentación de dos casos

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    El carcinoma primario de la trompa de Falopio es un tumor ginecológico raro. Su diagnóstico pre- operatorio se dificulta por su curso insidioso y silente, generalmente se realiza en el post-operatorio. Se presenta con mayor frecuencia en mujeres post menopaúsicas y clínica e histológicamente se comporta en muchas ocasiones como un cáncer de ovario. En la literatura se ha reportado la asociación entre cáncer de ovario y endometrio pero muy pocos han descrito la asociación de estos, con el cáncer de la trompa de Falopio. Se presentan dos casos de cáncer primario de la trompa de Falopio, diagnosticados en un período de 6 meses por histología post-quirúrgica, intervenidos en el Servicio de Ginecología del Hospital General Docente ¨Enrique Cabrera¨ y cuyos diagnósticos pre-operatorios fueron: adenocarcinoma de endometrio y cáncer de ovario. Es llamativo, que una de las pacientes, de 44 años, se le realiza el diagnóstico al realizar biopsia endometrial para retirar un dispositivo intrauterino y el resultado de dicho estudio fue un adenocarcinoma de endometrio que justifica la intervención quirúrgica
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