The 46359CT polymorphism of DNMT3B is associated with the risk of cervical cancer

Abnormal methylation is related to cancer development. Since DNMT3B is an enzyme that modulates genomic methylation, we hypothesized that genetic variants of the promoter DNMT3B may be associated with an increased risk of developing cervical cancer. Our aim was to investigate the association between ?579GT and 46359CT polymorphisms of DNMT3B and cervical cancer, high-grade squamous intraepithelial lesions (HSIL), and low-grade squamous intraepithelial lesions (LSIL). Samples from 200 healthy women and 130 women with squamous intraepithelial lesions (70 with cervical cancer, 30 with HSIL, and 30 with LSIL) were analyzed. Polymorphism genotyping was performed using PCR and restriction fragment length polymorphism. The ?579GT polymorphism was not associated with cervical cancer, HSIL, or LSIL. The CT genotype of 46359CT polymorphism was significantly associated with cervical cancer risk (OR 8.75, CI 1.27–374.1), whereas the TT genotype was associated with a significantly decreased risk of HSIL (OR 0.66, CI 0.01–0.32) and LSIL (OR 0.11, CI 0.026–0.45). Our results suggest that genotyping the 46359CT polymorphism in DNMT3B may help identify women who are genetically susceptible to cervical cancer development. Additional studies with larger sample sizes are necessary to confirm our findings.     

Growth Factor and Th2 Cytokine Signaling Pathways Converge at STAT6 to Promote Arginase Expression in Progressive Experimental Visceral Leishmaniasis

Host arginase 1 (arg1) expression is a significant contributor to the pathogenesis of progressive visceral leishmaniasis (VL), a neglected tropical disease caused by the intracellular protozoan Leishmania donovani. Previously we found that parasite-induced arg1 expression in macrophages was dependent on STAT6 activation. Arg1 expression was amplified by, but did not require, IL-4, and required de novo synthesis of unknown protein(s). To further explore the mechanisms involved in arg1 regulation in VL, we screened a panel of kinase inhibitors and found that inhibitors of growth factor signaling reduced arg1 expression in splenic macrophages from hamsters with VL. Analysis of growth factors and their signaling pathways revealed that the Fibroblast Growth Factor Receptor 1 (FGFR-1) and Insulin-like Growth Factor 1 Receptor (IGF-1R) and a number of downstream signaling proteins were activated in splenic macrophages isolated from hamsters infected with L. donovani. Recombinant FGF-2 and IGF-1 increased the expression of arg1 in L. donovani infected hamster macrophages, and this induction was augmented by IL-4. Inhibition of FGFR-1 and IGF-1R decreased arg1 expression and restricted L. donovani replication in both in vitro and ex vivo models of infection. Inhibition of the downstream signaling molecules JAK and AKT also reduced the expression of arg1 in infected macrophages. STAT6 was activated in infected macrophages exposed to either FGF-2 or IGF-1, and STAT6 was critical to the FGFR-1- and IGF-1R-mediated expression of arg1. The converse was also true as inhibition of FGFR-1 and IGF-1R reduced the activation of STAT6 in infected macrophages. Collectively, these data indicate that the FGFR/IGF-1R and IL-4 signaling pathways converge at STAT6 to promote pathologic arg1 expression and intracellular parasite survival in VL. Targeted interruption of these pathological processes offers an approach to restrain this relentlessly progressive disease.     

Developing a Social Autopsy Tool for Dengue Mortality: A Pilot Study

BackgroundDengue fever is a public health problem in the tropical and sub-tropical world. Dengue cases have grown dramatically in recent years as well as dengue mortality. Colombia has experienced periodic dengue outbreaks with numerous dengue related-deaths, where the Santander department has been particularly affected. Although social determinants of health (SDH) shape health outcomes, including mortality, it is not yet understood how these affect dengue mortality. The aim of this pilot study was to develop and pre-test a social autopsy (SA) tool for dengue mortality.ConclusionsThe SA tool is based on the scientific literature, a validated conceptual framework, researchers’ and health professionals’ expertise, and a pilot study. It is the first time that a SA tool has been created for the dengue mortality context. Our work furthers the study on SDH and how these are applied to neglected tropical diseases, like dengue. This tool could be integrated in surveillance systems to provide complementary information on the modifiable and avoidable death-related factors and therefore, be able to formulate interventions for dengue mortality reduction.     

Biodegradation of wastewater pollutants by activated sludge encapsulated inside calcium-alginate beads in a tubular packed bed reactor

The wastewater treatment plants produce large quantities of biomass (sludge) that require about one-third of the total inversion and operation plant costs for their treatment. By the microorganisms immobilization it is possible to handle high cell concentration in the reactor, increasing its efficiency, reducing the loss of biomass and the wash out is avoided. Moreover, there is no cell growth then the sludge production is reduced. In this study, the COD removal and VSS variation were modeled in a tubular reactor with activated sludge immobilized in Ca-alginate. Moreover, two aspects that are commonly not considered in the performance of the actual reactors of this kind were introduced; the performance in non-steady state and the dispersion effect. The model was calibrated with an actual wastewater taken out from a Mexican wastewater treatment plant. The results of the performance of the tubular bioreactor at different scenarios (i.e., different residence time and VSS in the reactor) are presented. With longer residence times and higher VSS concentration in the Ca-alginate beads in the tubular bioreactor it is possible to increase the time operation of the bioreactor and to treat higher volumes of wastewater. During the process, the sludge generation was drastically reduced and it is possible to remove nitrogen form the wastewater making this process more attractive.     

Cell-free complements in vivo expression of the E. coli membrane proteome

Reconstituted cell-free (CF) protein expression systems hold the promise of overcoming the traditional barriers associated with in vivo systems. This is particularly true for membrane proteins, which are often cytotoxic and due to the nature of the membrane, difficult to work with. To evaluate the potential of cell-free expression, we cloned 120 membrane proteins from E. coli and compared their expression profiles in both an E. coli in vivo system and an E. coli-derived cell-free system. Our results indicate CF is a more robust system and we were able to express 63% of the targets in CF, compared to 44% in vivo. To benchmark the quality of CF produced protein, five target membrane proteins were purified and their homogeneity assayed by gel filtration chromatography. Finally, to demonstrate the ease of amino acid labeling with CF, a novel membrane protein was substituted with selenomethionine, purified, and shown to have 100% incorporation of the unnatural amino acid. We conclude that CF is a novel, robust expression system capable of expressing more proteins than an in vivo system and suitable for production of membrane proteins at the milligram level.     

Colocalization of sensors is sufficient to activate the DNA damage checkpoint in the absence of damage

Previous work on the DNA damage checkpoint in Saccharomyces cerevisiae has shown that two complexes independently sense DNA lesions: the kinase Mec1-Ddc2 and the PCNA-like 9-1-1 complex. To test whether colocalization of these components is sufficient for checkpoint activation, we fused these checkpoint proteins to the LacI repressor and artificially colocalized these fusions by expressing them in cells harboring Lac operator arrays. We observed Rad53 and Rad9 phosphorylation, Sml1 degradation, and metaphase delay, demonstrating that colocalization of these sensors is sufficient to activate the checkpoint in the absence of DNA damage. Our tethering system allowed us to establish that CDK functions in the checkpoint pathway downstream of damage processing and checkpoint protein recruitment. This CDK dependence is likely, at least in part, through Rad9, since mutation of CDK consensus sites compromised its checkpoint function.