68 research outputs found
Arc Stability Characterization of Double Coated Electrodes for Hardfacing
The aim of this work is to establish the influence of the relative position of the alloy charge C-Cr-Mn in the structure of the coating of rutile electrodes for hardfacing, on the operational behavior (arc stability). For this, three variants of electrodes with similar chemical composition are elaborated in the metallic core and the coating, differentiating only in the relative position that occupies the alloy charge (C-Cr-Mn) in the structure of the coating: internal, external and homogeneous. For the development of the research, a completely random design is used. The operative characterization of the electrodes is performed in terms of the arc stability. In conclusion, it can be seen that the position of the alloy load influences the operation behavior (stability of the arc). The variant of internal alloy charge in the coating presents the better arc stability performance
Multilocus Genotyping of Pneumocystis jirovecii from Deceased Cuban AIDS Patients Using Formalin-Fixed and Paraffin-Embedded Tissues
The results of the genotypic characterization of Pneumocystis jirovecii are described in lung tissue samples from 41 Cubans who died of AIDS with pneumocystosis between 1995 and 2008. Histological sections of the lung preserved as formalin-fixed and paraffin-embedded tissue were examined. PCR amplification and nucleotide sequencing of the two mitochondrial genes (large and small) of the pathogen allowed verification of a predominance of genotype 3 (85T/248C) of the large mitochondrial gene and genotype 3 (160A/196T) of the small mitochondrial gene over a period of 14 years (1995–2008). These results suggest that the 85T/248C//160A/196T genotype circulates with the highest frequency (81.3%) among AIDS patients in Cuba. Multilocus analysis indicates a limited circulation of pathogen genotypes on the island with the existence of a clonal genotype with an epidemic structure. Furthermore, it appears that circulating strains of P. jirovecii have not developed mutations related to sulfonamide resistance. Taken together, the data in this study revealed important elements about pneumocystosis in Cuban patients dying of AIDS and the usefulness of formalin-fixed and paraffin-embedded samples to carry out molecular epidemiology studies of P. jirovecii
Clostridioides difficile-associated diarrhea in surgical service patients in Mexico
Introduction: Clostridium difficile is the first cause of healthcare-associated diarrhea in developed
countries. In recent years the incidence of C. difficile infection (CDI) has increased
worldwide. There is not much information on the topic in Mexico, and little is known about
the risk factors for the infection in patients that are hospitalized in surgical services.
Materials and methods: A case-control study was conducted that compared the epidemiologic
findings and risk factors between surgical patients with PCR-confirmed CDI, surgical patients
with diarrhea and a negative PCR test, and surgical patients with no diarrhea. The statistical
analysis was carried out using the SPSS version 22.0 program.
Results: The majority of the surgical patients with CDI belonged to the areas of neurosurgery,
cardiac surgery, orthopedics, and general surgery. A total of 53% of the CDI cases were associated
with the hypervirulent CD NAP1/027 strain. The presence of mucus in stools (OR: 1.5, p = 0.001),
fever (OR: 1.4, p = 0.011), leukocytes in stools (OR: 3.2, p < 0.001), hospitalization within the
past twelve weeks (OR: 2.0, p < 0.001), antibiotic use (OR: 1.3, p = 0.023), and ceftriaxone use
(OR: 1.4, p = 0.01) were independent risk factors for the development of CDI
Diarrea asociada a Clostridioides difficile en pacientes de servicios quirúrgicos en México
Introducción: Clostridioides difficile (CD) es la primera causa de diarrea asociada al cuidadode salud en los países desarrollados. En los últimos a˜nos, la incidencia de la infección asociadaa CD (ICD) ha aumentado en el ámbito mundial. En México, la información al respecto es escasay se conoce poco sobre los factores de riesgo para esta enfermedad en pacientes hospitalizadosen servicios quirúrgicosMaterial y métodos: Estudio de casos y controles. Se compararon hallazgos epidemiológicos yfactores de riesgo entre pacientes quirúrgicos con ICD confirmada por PCR contra pacientes qui-rúrgicos con diarrea PCR negativa y contra pacientes quirúrgicos sin diarrea. Se realizó análisisestadístico mediante el paquete estadístico SPSS versión 22.0.Resultados: La mayoría de los pacientes quirúrgicos con ICD correspondían a las áreas de neu-rocirugía, cardiocirugía, ortopedia y cirugía general. El 53% de los casos de ICD se asociaron a lacepa hipervirulenta de CD NAP1/027. La presencia de moco en heces (RM 1.5, p = 0.001), fiebre(RM 1.4, p = 0.011), leucocitos en heces (RM 3.2, p = < 0.001), hospitalización en las últimas12 semanas (RM 2.0, p = < 0.001), uso de antibióticos (RM 1.3, p = 0.023) y uso de ceftriaxona(RM 1.4, p = 0.01) constituyeron factores de riesgo independientes para el desarrollo de ICD.
Conclusiones: La diarrea por CD en servicios quirúrgicos es frecuente en nuestra institución(Hospital Civil de Guadalajara Fray Antonio Alcalde)
Discovery of circulating miRNAs as biomarkers of chronic Chagas heart disease via a small RNA-Seq approach
Chagas disease affects approximately 7 million people worldwide in Latin America and is a neglected tropical disease. Twenty to thirty percent of chronically infected patients develop chronic Chagas cardiomyopathy decades after acute infection. Identifying biomarkers of Chagas disease progression is necessary to develop better therapeutic and preventive strategies. Circulating microRNAs are increasingly reliable biomarkers of disease and therapeutic targets. To identify new circulating microRNAs for Chagas disease, we performed exploratory small RNA sequencing from the plasma of patients and performed de novo miRNA prediction, identifying potential new microRNAs. The levels of the new microRNAs temporarily named miR-Contig-1519 and miR-Contig-3244 and microRNAs that are biomarkers for nonchagasic cardiomyopathies, such as miR-148a-3p and miR-224-5p, were validated by quantitative reverse transcription. We found a specific circulating microRNA signature defined by low miR-Contig-3244, miR-Contig-1519, and miR-148a-3 levels but high miR-224-5p levels for patients with chronic Chagas disease. Finally, we predicted in silico that these altered circulating microRNAs could affect the expression of target genes involved in different cellular pathways and biological processes, which we will explore in the future.The funding was supported by Agencia Nacional e Promoción Científica y Tecnológica, PICT 2013-1892, Secretaría de Ciencia y Tecnología, Universidad Nacional de Rosario, 1MED410, Ministerio de Economía y competitividad and Fondo Europeo de Desarrollo Regional, SAF2016-75988-R (MINECO/FEDER), SAF2015-63868-R (MINECO/FEDER), Red de Investigación de Centros de Enfermedades Tropicales, RICET RD12/0018/0004, Consejería de Sanidad, Comunidad de Madrid, S-2010/BMD-2332, Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación and Fondo Europeo de Desarrollo Regional, PGC2018-096132-B-I00, and PID2021-123389OB-I00
Polimorfismos de los genes CCR5, IL-6, IFN-γ e IL-10 en pacientes cubanos con VIH/sidaPolymorphisms of CCR5, IL-6, IFN-γ and IL-10 genes in Cuban HIV/AIDS patients
[EN] Introduction: Genetic studies have shown associations of several single nucleotide polymorphisms (SNP) with different rates of progression and variation in susceptibility to HIV infection. This study aimed to estimate the frequency of ccr5Δ32, IL-6-174G/C, IFN-γ+874T/A and IL-10-1082A/G polymorphisms in Cuban HIV-infected patients and a group of sero-discordant couples to assess their influence on risk and disease progression. Methods: A cross-sectional study was carried out on 120 subjects registered at the Institute of Tropical Medicine «Pedro Kour» (IPK) and the Ameijeiras Hospital from June 2018 until December 2019. The amplification of fragments of the ccr5, IL-6, IFN-γ and IL-10 genes was performed by polymerase chain reaction followed by identification of polymorphisms using the restriction fragment length polymorphism analysis for IL-6 with the restriction enzymes Nla III. Amplification refractory mutation system was used for IFN-γ and IL-10 genes. Results: The allelic and genotypic distributions of the genes ccr5, IL-6, IFN-γ and IL-10 did not differ significantly between the two groups. Cell counts and plasma viral load values did not differ significantly between genotypes of the ccr5, IL-6, IFN-γ and IL-10 genes. Only the IL-6 GC genotype was associated with higher viral load values. The combination of alleles of the four considered SNPs showed a highly significant increase in the risk of HIV infection for one of them, but with a very low frequency (< 1%). Conclusion: This study contributes to evaluating the frequency of these polymorphisms and their influence on biomarkers of the progression of HIV infection in the Cuban HIV-population.[ES] Introducción: Los estudios genéticos han demostrado asociaciones de varios polimorfismos de un solo nucleótido (SNP) con diferentes tasas de progresión y variación en la susceptibilidad a la infección por VIH. Este estudio tuvo como objetivo estimar la frecuencia de los polimorfismos ccr5Δ32, IL-6-174G/C, IFN-γ+874T/A e IL-10-1082A/G en pacientes cubanos infectados por VIH y un grupo de parejas serodiscordantes para evaluar su influencia sobre el riesgo y la progresión de la enfermedad. Métodos: Se realizó un estudio transversal en 120 sujetos atendidos en el Instituto de Medicina Tropical «Pedro Kour» (IPK) y el Hospital Hermanos Ameijeiras entre junio de 2018 y diciembre de 2019. La amplificación de los fragmentos de los genes ccr5, IL-6, IFN-γ e IL-10 se realizó mediante reacción en cadena de la polimerasa seguida por el análisis del polimorfismo de fragmentos de restricción utilizando la enzima Nla III para la IL-6. El sistema de mutación refractario a la amplificación por PCR se utilizó en el caso de los genes IFN-γ e IL-10. Resultados: Las distribuciones alélicas y genotípicas de los genes ccr5, IL-6, IFN-γ e IL-10 no difirieron significativamente entre los dos grupos. Los recuentos celulares y los valores de carga viral en plasma no difirieron significativamente entre los genotipos de los genes ccr5, IL-6, IFN-γ e IL-10. Solo el genotipo IL-6 GC se asoció con valores más altos de carga viral. La combinación de alelos de los cuatro SNP considerados mostró un aumento muy significativo del riesgo de infección por VIH para uno de ellos, pero con una frecuencia muy baja (< 1%). Conclusión: Este estudio contribuye a evaluar la frecuencia de estos polimorfismos y su influencia en los biomarcadores de la progresión de la infección por VIH en la población cubana con infección por el VIH.Peer reviewe
The Quaternary Active Faults Database of Iberia (QAFI v.2.0)
The Quaternary Active Faults Database of Iberia (QAFI) is an initiative lead by the Institute of Geology and Mines of Spain (IGME) for building a public repository of scientific data regarding faults having documented activity during the last 2.59 Ma (Quaternary). QAFI also addresses a need to transfer geologic knowledge to practitioners of seismic hazard and risk in Iberia by identifying and characterizing seismogenic fault-sources. QAFI is populated by the information freely provided by more than 40 Earth science researchers, storing to date a total of 262 records. In this article we describe the development and evolution of the database, as well as its internal architecture. Aditionally, a first global analysis of the data is provided with a special focus on length and slip-rate fault parameters. Finally, the database completeness and the internal consistency of the data are discussed. Even though QAFI v.2.0 is the most current resource for calculating fault-related seismic hazard in Iberia, the database is still incomplete and requires further review
A case–control study of infections caused by Klebsiella pneumoniae producing New Delhi metallo-beta-lactamase-1: Predictors and outcomes
IntroductionInfections caused by antimicrobial-resistant bacteria are a significant cause of death worldwide, and carbapenemase-producing bacteria are the principal agents. New Delhi metallo-beta-lactamase-1 producing Klebsiella pneumoniae (KP-NDM-1) is an extensively drug-resistant bacterium that has been previously reported in Mexico. Our aim was to conduct a case–control study to describe the risk factors associated with nosocomial infections caused by K. pneumoniae producing NDM-1 in a tertiary-care hospital in Mexico.MethodsA retrospective case–control study with patients hospitalized from January 2012 to February 2018 at the Hospital Civil de Guadalajara “Fray Antonio Alcalde” was designed. During this period, 139 patients with a culture that was positive for K. pneumoniae NDM-1 (cases) and 486 patients hospitalized in the same department and on the same date as the cases (controls) were included. Data were analyzed using SPSS v. 24, and logistic regression analysis was conducted to calculate the risk factors for KP-NDM-1 infection.ResultsOne hundred and thirty-nine case patients with a KP-NDM-1 isolate and 486 control patients were analyzed. In the case group, acute renal failure was a significant comorbidity, hospitalization days were extended, and significantly more deaths occurred. In a multivariate analysis of risk factors, the independent variables included the previous use of antibiotics (odds ratio, OR = 12.252), the use of a urinary catheter (OR = 5.985), the use of a central venous catheter (OR = 5.518), the use of mechanical ventilation (OR = 3.459), and the length of intensive care unit (ICU) stay (OR = 2.334) as predictors of infection with NDM-1 K. pneumoniae.ConclusionIn this study, the previous use of antibiotics, the use of a urinary catheter, the use of a central venous catheter, the use of mechanical ventilation, and ICU stay were shown to be predictors of infection with NDM-1 K. pneumoniae and were independent risk factors for infection with NDM-1 K. pneumoniae
RANK is an independent biomarker of poor prognosis in estrogen receptor-negative breast cancer and a therapeutic target in patient-derived xenografts
Despite strong preclinical data, the therapeutic benefit of the RANKL inhibitor denosumab in BC patients, beyond its bone-related effects, is unclear. Here, we investigated the prognostic value of RANK expression and its functionality in human BC. We analyzed RANK and RANKL expression in more than 1500 BC cases (777 being estrogen receptor-negative (ER-)) from four independent cohorts. We confirmed that RANK is more frequently expressed in ER- tumors, but it is also found in a subset of ER+ tumors. In ER- BC, RANK expression was independently associated with poor outcome, especially in postmenopausal patients and those who received adjuvant chemotherapy. Gene expression analyses unraveled distinct biology associated with RANK in relation to ER expression and menopause, and evidenced enhanced RANK activation in ER- postmenopausal tumors, together with regulation of metabolic pathways. Functional studies and transcriptomic analyses in ER- RANK+ patients-derived orthoxenografts demonstrated that activation of RANK signaling pathway promotes tumor cell proliferation and stemness, and regulates multiple biological processes including tumor immune surveillance and metabolism. Our results demonstrate that RANK expression is an independent poor prognosis biomarker in postmenopausal ER- BC patients and support the rational of using RANK pathway inhibitors in combination with chemotherapy in ER- BC.N
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