33 research outputs found
Sistema de gestión de calidad para el Call Center Pronto BPO El Salvador, con base a ISO 9001:2015.
El punto de partida de este trabajo de investigación se origina en el estudio realizado a la empresa Pronto BPO El Salvador, quien al ser una empresa reciente en nuestro país, y con un record favorable entre los usuarios de los servicios de Pronto BPO Guatemala y Pronto BPO República Dominicana; los clientes internacionales han buscado su asistencia para la recepción de llamadas, sin embargo, esto no ha sido posible debido a la falta de un sistema de gestión de calidad que le garantice a los usuarios que van a recibir lo solicitado. Además, de no contar con un modelo de administración de los recursos y orientación de empleados que fomente, regule y permita conseguir mejores resultados y busque incrementar la satisfacción de los clientes. A través del Manual de Calidad propuesto se tiene por objeto proporcionar a Pronto BPO El Salvador, una herramienta estratégica que sustente los requisitos de gestión de calidad de la norma ISO 9001:2015, para generar conciencia a todos los niveles, desde la alta dirección hasta los teleoperadores, sobre las cuestiones que deben ser consideradas para proyectar confianza sobre su capacidad de suministrar servicios de call center que satisfacen las necesidades de los clientes, con una óptica de mejora continua de los servicios, procesos y sistema de gestión de calidad. Para llevar a cabo la investigación se utilizó el enfoque cualitativo, ya que, por la naturaleza del trabajo se requería de un método flexible y que proporcionara información precisa sobre la manera de operar de la entidad en estudio. Por consiguiente, a partir de dicho enfoque, el tipo de investigación utilizado es de carácter (1) exploratorio, porque nunca se había trabajo un sistema de gestión de calidad para un trabajo de grado de la carrera de contaduría pública de la Universidad de El Salvador; (2) descriptivo, se conoció cómo es, cómo opera y cómo está compuesto un call center y (3) correlacional, se visualizó la asociación de procesos gerenciales, administrativos y operativos, con el área de servicio al cliente. De acuerdo a los resultados obtenidos por medio de entrevistas orientadas a los cargos relacionados directamente con el área de servicio al cliente, como lo son la gerencia y supervisión, se sabe que existen deficiencias con relación a (1) la comprensión del propósito que la empresa persigue a través de la entrega de sus servicios, (2) conocimiento y comprensión de requisitos de un sistema de gestión de calidad, (3) los conocimientos y habilidades de algunos contratados, (4) claridad de las actividades que se realizan en el proceso de call center y supervisión. Por lo anterior, es necesario establecer un Departamento de Control de Calidad que colabore en la implementación, mantenimiento y mejora del sistema de gestión de calidad; además, de concientizar a todo el personal que tenga una relación directa con el área de servicio al cliente, sobre la importancia de dicho sistema, el efecto que tiene un buen desempeño de sus labores y la búsqueda de la satisfacción de cliente, y aún más, ser la diferencia entre las otras organizaciones que se desenvuelven en el mismo ámbito económico
The structure of Leptospira interrogans GAPDH sheds light into an immunoevasion factor that can target the anaphylatoxin C5a of innate immunity
Leptospirosis is a neglected worldwide zoonosis involving farm animals and domestic pets caused by the Gram-negative spirochete Leptospira interrogans. This bacterium deploys a variety of immune evasive mechanisms, some of them targeted at the complement system of the host’s innate immunity. In this work, we have solved the X-ray crystallographic structure of L. interrogans glyceraldehyde-3-phosphate dehydrogenase (GAPDH) to 2.37-Å resolution, a glycolytic enzyme that has been shown to exhibit moonlighting functions that potentiate infectivity and immune evasion in various pathogenic organisms. Besides, we have characterized the enzyme’s kinetic parameters toward the cognate substrates and have proven that the two natural products anacardic acid and curcumin are able to inhibit L. interrogans GAPDH at micromolar concentration through a noncompetitive inhibition modality. Furthermore, we have established that L. interrogans GAPDH can interact with the anaphylatoxin C5a of human innate immunity in vitro using bio-layer interferometry and a short-range cross-linking reagent that tethers free thiol groups in protein complexes. To shed light into the interaction between L. interrogans GAPDH and C5a, we have also carried out cross-link guided protein-protein docking. These results suggest that L. interrogans could be placed in the growing list of bacterial pathogens that exploit glycolytic enzymes as extracellular immune evasive factors. Analysis of the docking results indicates a low affinity interaction that is consistent with previous evidence, including known binding modes of other α-helical proteins with GAPDH. These findings allow us to propose L. interrogans GAPDH as a potential immune evasive factor targeting the complement system
The MADS-box XAANTAL1 increases proliferation at the Arabidopsis root stem-cell niche and participates in transition to differentiation by regulating cell-cycle components
Background Morphogenesis depends on the concerted modulation of cell proliferation and differentiation. Such modulation is dynamically adjusted in response to various external and internal signals via complex transcriptional regulatory networks that mediate between such signals and regulation of cell-cycle and cellular responses (proliferation, growth, differentiation). In plants, which are sessile, the proliferation/differentiation balance is plastically adjusted during their life cycle and transcriptional networks are important in this process. MADS-box genes are key developmental regulators in eukaryotes, but their role in cell proliferation and differentiation modulation in plants remains poorly studied.
Methods We characterize the XAL1 loss-of-function xal1-2 allele and overexpression lines using quantitative cellular and cytometry analyses to explore its role in cell cycle, proliferation, stem-cell patterning and transition to differentiation. We used quantitative PCR and cellular markers to explore if XAL1 regulates cell-cycle components and PLETHORA1 (PLT1) gene expression, as well as confocal microscopy to analyse stem-cell niche organization.
Key Results We previously showed that XAANTAL1 (XAL1/AGL12) is necessary for Arabidopsis root development as a promoter of cell proliferation in the root apical meristem. Here, we demonstrate that XAL1 positively regulates the expression of PLT1 and important components of the cell cycle: CYCD3;1, CYCA2;3, CYCB1;1, CDKB1;1 and CDT1a. In addition, we show that xal1-2 mutant plants have a premature transition to differentiation with root hairs appearing closer to the root tip, while endoreplication in these plants is partially compromised. Coincidently, the final size of cortex cells in the mutant is shorter than wild-type cells. Finally, XAL1 overexpression-lines corroborate that this transcription factor is able to promote cell proliferation at the stem-cell niche.
ConclusionXAL1 seems to be an important component of the networks that modulate cell proliferation/differentiation transition and stem-cell proliferation during Arabidopsis root development; it also regulates several cell-cycle components.This work constitutes a partial fulfilment of the Graduate Program ‘Doctorado en Ciencias Biomédicas’ of the Universidad Nacional Autónoma de México in which Karla V. García-Cruz developed this project. We acknowledge the Consejo Nacional de Ciencia y Tecnología (CONACYT, México) that provided her scholarship. This work was supported by CONACYT: 240180 and 180380; PAPIIT, UNAM: IN203214-3; IN203113-3; IN203814-3; IN211516 and BFU2012-34821 from MINECO (Spain) to C.G., and an institutional grant from Fundación Ramón Areces to Centro de Biología Molecular Severo Ochoa. We thank David Cruz Sánchez and Diana Romo for technical and logistical support, respectively.Peer reviewe
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
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
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Structural biology of complement receptors
The complement system plays crucial roles in a wide breadth of immune and inflammatory processes and is frequently cited as an etiological or aggravating factor in many human diseases, from asthma to cancer. Complement receptors encompass at least eight proteins from four structural classes, orchestrating complement-mediated humoral and cellular effector responses and coordinating the complex cross-talk between innate and adaptive immunity. The progressive increase in understanding of the structural features of the main complement factors, activated proteolytic fragments, and their assemblies have spurred a renewed interest in deciphering their receptor complexes. In this review, we describe what is currently known about the structural biology of the complement receptors and their complexes with natural agonists and pharmacological antagonists. We highlight the fundamental concepts and the gray areas where issues and problems have been identified, including current research gaps. We seek to offer guidance into the structural biology of the complement system as structural information underlies fundamental and therapeutic research endeavors. Finally, we also indicate what we believe are potential developments in the field
Crystal structure and SAXS analysis of the immune evasive factor GAPDH from Leptospira interrogans
1 p.Background: Immune evasive factors from pathogenic bacteriainclude metabolic enzymes that fulfill housekeeping roles intra-cellularly but which can contribute to infectivity when released as part of the bacterial secretome. The glycolytic enzyme D-glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been characterized as a moonlighting protein with immune evasive roles in many gram-negative and gram-positive bacteria (1-2). GAPDH from several bacterial pathogens are known to interfere with the C5a-C5aR1 signaling pathway by binding to C5a. There-fore, research to determine the structural features enabling C5a sequestration and the potential for pharmacological intervention represent interesting alternatives to fight bacterial infections.Methods: The gene for Leptospira interrogans (Li)GAPDH wasamplified from gDNA and subcloned into a bacterial expression vector. Expression and purification of LiGAPDH was performed following established procedures. The structure of LiGAPDH wasdetermined by X-ray crystallography and the shape in solution calculated from small-angle X-ray diffraction (SAXS). A crosslinkingassay with BMOE helped to demonstrate the association between LiGAPDH and human C5a. GAPDH activity was measured with standard enzymatic assays and inhibition by two natural products (curcumin and anacardic acid) was evaluated.Results: We have cloned, expressed and purified GAPDH from Leptospira interrogans. We have crystallized it and solved its struc-ture by X-ray crystallography. In addition, we have restored itsshape in solution, validating the crystallographic model. LiGAPDH appears to be able to engage in a transient complex with human C5a, which we have trapped by crosslinking with BMOE, a highlyspecific reagent that crosslinks thiols < 6-8˚A away. We have analyzed the inhibitory potency and inhibition modality of two natural products with antimicrobial properties: anacardic acid and curcumin. Of them, only curcumin showed inhibition potential.Conclusions: The structure of the immune evasive factor GAPDH from Leptospira interrogans has been determined and is now available for experimental and computational drug discovery campaigns. Although weakly, LiGAPDH can interact with human C5a, suggesting that avidity effects caused by the concentration of GAPDH on the bacterium’s cell wall could enhance the C5a sequestration capacity of L. interrogans. Furthermore, curcumin has emerged as an interesting broad-spectrum inhibitor of LiGAPDH.Peer reviewe
A Dynamic Gene Regulatory Network Model That Recovers the Cyclic Behavior of Arabidopsis thaliana Cell Cycle.
Cell cycle control is fundamental in eukaryotic development. Several modeling efforts have been used to integrate the complex network of interacting molecular components involved in cell cycle dynamics. In this paper, we aimed at recovering the regulatory logic upstream of previously known components of cell cycle control, with the aim of understanding the mechanisms underlying the emergence of the cyclic behavior of such components. We focus on Arabidopsis thaliana, but given that many components of cell cycle regulation are conserved among eukaryotes, when experimental data for this system was not available, we considered experimental results from yeast and animal systems. We are proposing a Boolean gene regulatory network (GRN) that converges into only one robust limit cycle attractor that closely resembles the cyclic behavior of the key cell-cycle molecular components and other regulators considered here. We validate the model by comparing our in silico configurations with data from loss- and gain-of-function mutants, where the endocyclic behavior also was recovered. Additionally, we approximate a continuous model and recovered the temporal periodic expression profiles of the cell-cycle molecular components involved, thus suggesting that the single limit cycle attractor recovered with the Boolean model is not an artifact of its discrete and synchronous nature, but rather an emergent consequence of the inherent characteristics of the regulatory logic proposed here. This dynamical model, hence provides a novel theoretical framework to address cell cycle regulation in plants, and it can also be used to propose novel predictions regarding cell cycle regulation in other eukaryotes