Green Synthesis of Stable Spherical Monodisperse Silver Nanoparticles Using a Cell-Free Extract of Trichoderma reesei

In the current study, a green method for the preparation of silver nanoparticles (AgNPs) is presented as an alternative to conventional chemical and physical approaches. A biomass of Trichoderma reesei (T. reesei) fungus was used as a green and renewable source of reductase enzymes and metabolites, which are capable of transforming Ag⁺ ions into AgNPs with a small size (mainly 2–6 nm) and narrow size distribution (2–25 nm). Moreover, extracellular biosynthesis was carried out with a cell-free water extract (CFE) of T. reesei, which allows for facile monitoring of the bioreduction process using UV–Vis spectroscopy and investigation of the effect of experimental conditions on the transformation of Ag⁺ ions into AgNPs, as well as the simple isolation of as-prepared AgNPs for the study of their size, morphology and antibacterial properties. In continuation to our previous results about the influence of media on T. reesei cultivation, the amount of biomass used for CFE preparation and the concentration of Ag⁺ ion solution, herein, we present the impact of temperature (4, 20, 30 and 40 °C), agitation and time duration on the biosynthesis of AgNPs and their properties. A high stability of AgNPs in aqueous colloids was observed and attributed to the capping effect of the biomolecules as shown by the zeta potential (−49.0/−51.4 mV) and confirmed by the hydrodynamic size of 190.8/116.8 nm of AgNPs.     

Tiempo en rango terapéutico e incidencia de complicaciones por warfarina en una cohorte retrospectiva de 20 años

ObjetivoCaracterizar el tiempo en rango terapéutico (TTR) y estimar la tasa de incidencia de complicaciones (PTIRc) en adultos con protocolo de warfarina.DiseñoCohorte retrospectiva basada en registros médicos de pacientes mayores de 18 años entre 1996 a 2016 y seguidos al menos tres meses.EmplazamientoUnidad de Hematología de un centro especializado cardiovascular venezolano.ParticipantesRegistros médicos electrónicos.Mediciones principalesTTR y PTIRc. Las variables fueron: sexo, analfabetismo funcional, ocupación, international normalized ratio (INR) y tiempo de seguimiento, que fueron analizados con TTR and PTIRc mediante modelos de logística binomial y regresión de Poisson, respectivamente.ResultadosUn total de 2.770 pacientes fueron seguidos durante 1.201.380 días; el 42,3% tuvieron un TTR < 65% y el 3,5% tuvieron indicación de INR 2,5-3,5. El 61,8% presentaron complicaciones. La PTIRc fue de 6,84/100 personas-mes (IC 95%: 6,56-7,15). TTR < 65% mostró OR ajustadas significativas con analfabetismo funcional e INR 2,5-3,5, mientras que para la mayor PTIRc se encontró un RR significativo en los dos factores mencionados, menor tiempo de seguimiento, TTR < 65% y en mujeres.ConclusionesA pesar de nuevos tratamientos anticoagulantes, la warfarina es útil. A medida que aumentó el tiempo de seguimiento el control fue mejor y la velocidad de aparición de complicaciones disminuyó; sin embargo, las condiciones que mostraron menor TTR y mayor velocidad de aparición de complicaciones requieren una profunda revisión del seguimiento, de manera especial en pacientes con analfabetismo funcional.Palabras clave: Warfarina, Estudio retrospectivo, Uso terapéutico, INR, Analfabetismo funcional     

Screening protocol for the identification of modulators by immunofluorescent cell‐based assay

High‐throughput assays are a common strategy for the identification of compounds able to modulate a certain cellular activity. Here, we show an automatized analysis platform for the quantification of nuclear foci as inhibitory effect of compounds on a target protein labeled by fluorescent antibodies. Our experience led us to a fast analysis platform that combines cell‐based assays, high‐content screening, and confocal microscopy, with an automatic and user‐friendly statistical analysis of plate‐based assays including positive and negative controls, able to identify inhibitory effect of compounds tested together with the Z‐prime and Window of individual plate‐based assays to assess the reliability of the results. The platform integrates a web‐based tool implemented in Pipeline Pilot and R, and allows computing the inhibition values of different parameters obtained from the high‐content screening and confocal microscopy analysis. This facilitates the exploration of the results using the different parameters, providing information at different levels as the number of foci observed, the sum of intensity of foci, area of foci, etc, the detection and filtering of outliers over the assay plate, and finally providing a set of statistics of the parameters studied together with a set of plots that we believe significantly helps to the interpretation of the assay results.     

Variants in activators and downstream targets of ATM, radiation exposure, and contralateral breast cancer risk in the WECARE study

Ionizing radiation (IR) is a breast carcinogen that induces DNA double-strand breaks (DSBs), and variation in genes involved in the DNA DSB response has been implicated in radiation-induced breast cancer. The Women's Environmental, Cancer, and Radiation Epidemiology (WECARE) study is a population-based study of cases with contralateral breast cancer (CBC) and matched controls with unilateral breast cancer. The location-specific radiation dose received by the contralateral breast was estimated from radiotherapy records and mathematical models. One hundred fifty-two SNPs in six genes (CHEK2, MRE11A, MDC1, NBN, RAD50, TP53BP1) involved in the DNA DSBs response were genotyped. No variants or haplotypes were associated with CBC risk (649 cases and 1,284 controls) and no variants were found to interact with radiation dose. Carriers of a RAD50 haplotype exposed to ≥1 gray (Gy) had an increased risk of CBC compared with unexposed carriers (Rate ratios [RR] = 4.31 [95% confidence intervals [CI] 1.93-9.62]); with an excess relative risk (ERR) per Gy = 2.13 [95% CI 0.61-5.33]). Although the results of this study were largely null, carriers of a haplotype in RAD50 treated with radiation had a greater CBC risk than unexposed carriers. This suggests that carriers of this haplotype may be susceptible to the DNA-damaging effects of radiation therapy associated with radiation-induced breast cancer.     

An assessment of estimation methods for generalized linear mixed models with binary outcomes

Two main classes of methodology have been developed for addressing the analytical intractability of generalized linear mixed models: likelihood‐based methods and Bayesian methods. Likelihood‐based methods such as the penalized quasi‐likelihood approach have been shown to produce biased estimates especially for binary clustered data with small clusters sizes. More recent methods using adaptive Gaussian quadrature perform well but can be overwhelmed by problems with large numbers of random effects, and efficient algorithms to better handle these situations have not yet been integrated in standard statistical packages. Bayesian methods, although they have good frequentist properties when the model is correct, are known to be computationally intensive and also require specialized code, limiting their use in practice. In this article, we introduce a modification of the hybrid approach of Capanu and Begg, 2011, Biometrics 67 , 371–380, as a bridge between the likelihood‐based and Bayesian approaches by employing Bayesian estimation for the variance components followed by Laplacian estimation for the regression coefficients. We investigate its performance as well as that of several likelihood‐based methods in the setting of generalized linear mixed models with binary outcomes. We apply the methods to three datasets and conduct simulations to illustrate their properties. Simulation results indicate that for moderate to large numbers of observations per random effect, adaptive Gaussian quadrature and the Laplacian approximation are very accurate, with adaptive Gaussian quadrature preferable as the number of observations per random effect increases. The hybrid approach is overall similar to the Laplace method, and it can be superior for data with very sparse random effects. Copyright © 2013 John Wiley & Sons, Ltd.     

Portopulmonary hypertension: from diagnosis to treatment

Portopulmonary hypertension is a form of pulmonary arterial hypertension that has gained interest in recent years with the development of liver transplantation techniques and new pulmonary vasodilator therapies. Portopulmonary hypertension is defined as pulmonary artery hypertension associated with portal hypertension with or without advanced hepatic disease. Echocardiography plays a major role in screening for portopulmonary hypertension but right heart catheterization remains the gold standard for diagnosis. The treatment of patients with portopulmonary hypertension consists of general measures that apply to all patients that carry the diagnosis of pulmonary hypertension and specific vasodilator therapies. These new therapies showed encouraging results in patients who would otherwise have a contraindication for liver transplantation. The review presents a summary of the current knowledge on the epidemiology, diagnosis, treatment and prognosis of patients with portopulmonary hypertension.     

Response to Neoadjuvant Chemotherapy Does Not Predict Overall Survival for Patients With Synchronous Colorectal Hepatic Metastases

Objective  We investigated the relation between response to neoadjuvant chemotherapy and overall survival (OS) in patients with colorectal liver metastases (CLM). Background  It has previously been reported that patients with synchronous CLM whose disease progresses while receiving neoadjuvant chemotherapy or who do not receive neoadjuvant chemotherapy experience worse survival than patients whose disease responds to neoadjuvant chemotherapy. Methods  By means of a prospectively maintained surgical database, between 1995 and 2003, we identified 111 patients with a synchronous CLM who received neoadjuvant chemotherapy before hepatic resection. The disease of all 111 patients was deemed resectable, and patients underwent hepatic resection with curative intent. Results  The median OS after liver resection was 62 months, with a median follow-up of 63 months. Median OS was similar between the three study groups classified by response to neoadjuvant chemotherapy (complete or partial response, 58 months; stable disease, 65 months; and disease progression, 61 months; P = .98). By univariate analysis, carcinoembryonic antigen level after liver resection of <5 ng/dL, size of metastatic lesion of ≤5 cm, lymph node–negative primary tumor, and disease-negative margins were associated with improved survival. Patients in the disease progression group had more positive margins and metastases >5 cm in size than patients in the complete or partial response group and the stable disease group. Patients whose tumor progressed but who received postoperative hepatic arterial infusion had a trend toward improved survival compared with those who did not receive hepatic arterial infusion (70% vs. 50% at 3 years, permutation log rank test P = .12). Conclusions  Response to neoadjuvant chemotherapy did not correlate with OS even after controlling for margins, stage of primary tumor, and postoperative carcinoembryonic antigen level. Postoperative salvage treatment may have helped the survival of some patients.