79 research outputs found

    Genome-Wide Mutagenesis Reveals That ORF7 Is a Novel VZV Skin-Tropic Factor

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    The Varicella Zoster Virus (VZV) is a ubiquitous human alpha-herpesvirus that is the causative agent of chicken pox and shingles. Although an attenuated VZV vaccine (v-Oka) has been widely used in children in the United States, chicken pox outbreaks are still seen, and the shingles vaccine only reduces the risk of shingles by 50%. Therefore, VZV still remains an important public health concern. Knowledge of VZV replication and pathogenesis remains limited due to its highly cell-associated nature in cultured cells, the difficulty of generating recombinant viruses, and VZV's almost exclusive tropism for human cells and tissues. In order to circumvent these hurdles, we cloned the entire VZV (p-Oka) genome into a bacterial artificial chromosome that included a dual-reporter system (GFP and luciferase reporter genes). We used PCR-based mutagenesis and the homologous recombination system in the E. coli to individually delete each of the genome's 70 unique ORFs. The collection of viral mutants obtained was systematically examined both in MeWo cells and in cultured human fetal skin organ samples. We use our genome-wide deletion library to provide novel functional annotations to 51% of the VZV proteome. We found 44 out of 70 VZV ORFs to be essential for viral replication. Among the 26 non-essential ORF deletion mutants, eight have discernable growth defects in MeWo. Interestingly, four ORFs were found to be required for viral replication in skin organ cultures, but not in MeWo cells, suggesting their potential roles as skin tropism factors. One of the genes (ORF7) has never been described as a skin tropic factor. The global profiling of the VZV genome gives further insights into the replication and pathogenesis of this virus, which can lead to improved prevention and therapy of chicken pox and shingles

    EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

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    More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

    20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years

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    The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment

    Long-term outcomes for neoadjuvant versus adjuvant chemotherapy in early breast cancer: meta-analysis of individual patient data from ten randomised trials

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    Background Neoadjuvant chemotherapy (NACT) for early breast cancer can make breast-conserving surgery more feasible and might be more likely to eradicate micrometastatic disease than might the same chemotherapy given after surgery. We investigated the long-term benefits and risks of NACT and the influence of tumour characteristics on outcome with a collaborative meta-analysis of individual patient data from relevant randomised trials. Methods We obtained information about prerandomisation tumour characteristics, clinical tumour response, surgery, recurrence, and mortality for 4756 women in ten randomised trials in early breast cancer that began before 2005 and compared NACT with the same chemotherapy given postoperatively. Primary outcomes were tumour response, extent of local therapy, local and distant recurrence, breast cancer death, and overall mortality. Analyses by intention-to-treat used standard regression (for response and frequency of breast-conserving therapy) and log-rank methods (for recurrence and mortality). Findings Patients entered the trials from 1983 to 2002 and median follow-up was 9 years (IQR 5–14), with the last follow-up in 2013. Most chemotherapy was anthracycline based (3838 [81%] of 4756 women). More than two thirds (1349 [69%] of 1947) of women allocated NACT had a complete or partial clinical response. Patients allocated NACT had an increased frequency of breast-conserving therapy (1504 [65%] of 2320 treated with NACT vs 1135 [49%] of 2318 treated with adjuvant chemotherapy). NACT was associated with more frequent local recurrence than was adjuvant chemotherapy: the 15 year local recurrence was 21·4% for NACT versus 15·9% for adjuvant chemotherapy (5·5% increase [95% CI 2·4–8·6]; rate ratio 1·37 [95% CI 1·17–1·61]; p=0·0001). No significant difference between NACT and adjuvant chemotherapy was noted for distant recurrence (15 year risk 38·2% for NACT vs 38·0% for adjuvant chemotherapy; rate ratio 1·02 [95% CI 0·92–1·14]; p=0·66), breast cancer mortality (34·4% vs 33·7%; 1·06 [0·95–1·18]; p=0·31), or death from any cause (40·9% vs 41·2%; 1·04 [0·94–1·15]; p=0·45). Interpretation Tumours downsized by NACT might have higher local recurrence after breast-conserving therapy than might tumours of the same dimensions in women who have not received NACT. Strategies to mitigate the increased local recurrence after breast-conserving therapy in tumours downsized by NACT should be considered—eg, careful tumour localisation, detailed pathological assessment, and appropriate radiotherapy

    Un recorrido por la Universidad de Nariño

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    El constante crecimiento que ha tenido la Universidad de Nariño a nivel académico, docente y estudiantil, ha llevado a la expansión de su planta física, al mejoramiento en su estructura que ofrece mayores y mejores servicios; siendo evidente la preocupación de la misma por el bienestar universitario y la proyección hacia la comunidad en general. Este constante crecimiento ha traído un desconocimiento de lo que es y tiene la Universidad de Nariño, limitante para que la comunidad utilice de la mejor manera todos los recursos con los que cuenta, impidiendo así la adquisición de nuevos conocimientos y un espíritu investigativo. Lo anterior implica que es necesario fomentar no solo un mayor conocimiento a nivel académico sino también a nivel estructural o físico, para mostrar a la sociedad lo mejor que ella posee, permitiendo un acercamiento Universidad - estudiantes - sociedad. El trabajo fue llevado a cabo en un período de 18 meses, el cual fue necesario para realizar la metodología propuesta: Recolección de la información de los servicios; el documento base de los servicios; selección del lenguaje para usar en la navegación y el recorrido a través de formatos Web y la implementación de la aplicación en Realidad Virtual. El sistema base propuesto fue implementado sobre plataforma Web. La aplicación tuvo como esquema principal la construcción basada en Realidad Virtual de la Ciudad Universitaria Torobajo y la información de los servicios que prestan las Dependencias de la Universidad de Nariño en diseño Web. Con “UN RECORRIDO POR LA UNIVERSIDAD DE NARIÑO”, se obtuvo una aplicación que genera conocimiento empírico, puesto que el fin es permitir a la comunidad en general conocer los espacios físicos de la Universidad de Nariño sede Torobajo, a través, de un método práctico y definitivo, utilizando la Realidad Virtual, que maneja con mayor facilidad lo lúdico, interactivo e innovador, herramientas fundamentales que empleadas de manera pedagógica contribuyen en el proceso enseñanza – aprendizaje a través del computador

    Laboratory assays with non-forced exposure to predict the preferential spatial distribution of fish in two ecuadorian rivers

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    Trabajo presentado en la SETAC Europe 27th Annual Meeting (Environmental Quality Through Transdisciplinary Collaboration), celebrada en Bruselas del 7 al 11 de mayo de 2017.Laboratory aquatic ecotoxicity assays used to provide data for ecological risk assessments assume that, under natural conditions, organisms living in a contaminated habitat are mandatorily and continuously exposed to contaminants. This assumption neglects the ability of the organisms to detect and avoid contamination moving towards less disturbed habitats such as expected in fluvial systems. Along a river, contaminants can be dispersed forming a gradient or even be patchy distributed, conditioning the habitat selection process by organisms as well as their avoidance and preference behavior. Therefore, in the present study, we assessed the avoidance and preference responses of the model fish Danio rerio when exposed to water samples from two Ecuadorian rivers (Pescadillo River and Oro River) with different disturbance levels. A non-forced exposure system, in which water samples from different river points are simultaneously assayed, allowing organisms to move freely between river samples and select the most favorable sample, was used. Results showed that organisms presented a trend to avoid Pescadillo River upstream samples, moving downstream towards to the confluence zone with Oro River. On the other hand, fish exposed to Oro River samples preferred moving upstream. When exposed to samples from both rivers simultaneously, fish tended to prefer Oro River samples. These results leaded us to predict that, as both rivers are connected, fish avoiding environmental disturbers in Pescadillo River would move to Oro River. Therefore, effects of potential stressful conditions present in Pescadillo River that trigger avoidance response by fish may depress fish populations in that river and, indirectly, affect Oro River by inducing an unexpected fish immigration.N

    Ent-Beyerane Diterpenes as a Key Platform for the Development of ArnT-Mediated Colistin Resistance Inhibitors

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    Colistin is a last-resort antibiotic for the treatment of multidrug resistant Gram-negative bacterial infections. Recently, a natural ent-beyerene diterpene was identified as a promising inhibitor of the enzyme responsible for colistin resistance mediated by lipid A aminoarabinosylation in Gram-negative bacteria, namely, ArnT (undecaprenyl phosphate-alpha-4-amino-4-deoxy-l-arabinose arabinosyl transferase). Here, semisynthetic analogues of hit were designed, synthetized, and tested against colistin-resistant Pseudomonas aeruginosa strains including clinical isolates to exploit the versatility of the diterpene scaffold. Microbiological assays coupled with molecular modeling indicated that for a more efficient colistin adjuvant activity, likely resulting from inhibition of the ArnT activity by the selected compounds and therefore from their interaction with the catalytic site of ArnT, an ent-beyerane scaffold is required along with an oxalate-like group at C-18/C-19 or a sugar residue at C-19 to resemble L-Ara4N. The ent-beyerane skeleton is identified for the first time as a privileged scaffold for further cost-effective development of valuable colistin resistance inhibitors
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