The immune landscape in tuberculosis reveals populations linked to disease and latency

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Relationship between Tobacco,cagA and vacA i1 Virulence Factors and Bacterial Load in Patients Infected by Helicobacter pylori

MethodsBiopsies of the gastric corpus and antrum from 155 consecutive patients in whom there was clinical suspicion of infection by H. pylori were processed. In 106 patients H. pylori infection was detected. Molecular methods were used to quantify the number of microorganisms and presence of cagA and vacA i1 genes. A standardized questionnaire was used to obtain patients’ clinical data and lifestyle variables, including tobacco and alcohol consumption. Adjusted Odds Ratios (OR_adjusted) were estimated by unconditional logistic regression.ResultscagA was significantly associated with active-smoking at endoscope: OR_adjusted 4.52. Evidence of association was found for vacA i1 (OR_adjusted 3.15). Bacterial load was higher in active-smokers, although these differences did not yield statistical significance (median of 262.2 versus 79.4 copies of H. pylori per cell).ConclusionsThe association between smoking and a higher risk of being infected by a virulent bacterial population and with higher bacterial load, support a complex interaction between H. pylori infection and environmental factors.     

Influence of continental history on the ecological specialization and macroevolutionary processes in the mammalian assemblage of South America: Differences between small and large mammals

Background  

This paper tests Vrba's resource-use hypothesis, which predicts that generalist species have lower specialization and extinction rates than specialists, using the 879 species of South American mammals. We tested several predictions about this hypothesis using the biomic specialization index (BSI) for each species, which is based on its geographical range within different climate-zones. The four predictions tested are: (1) there is a high frequency of species restricted to a single biome, which henceforth are referred to as stenobiomic species, (2) certain clades are more stenobiomic than others, (3) there is a higher proportion of biomic specialists in biomes that underwent through major expansion-contraction alternation due to the glacial-interglacial cycles, (4) certain combinations of inhabited biomes occur more frequently among species than do others.     

Final touches and quality control on the assembly of the eukaryotic ribosome

One of the most fundamental processes of life is protein synthesis by the ribosome. Although much is known about the function and structure of this macromolecular complex, our understanding on its assembly is still vague. In this issue of The EMBO Journal, Malyutin et al ( 2017 ) provide a detailed picture of one of the latest assembly stages of the yeast 60S ribosomal subunit. The cryo-EM map of the 60S-Nmd3-Lsg1-Tif6 complex sheds new light on the function of Nmd3, Lsg1 and Tif6—and their release mechanisms—right before the 60S subunit joins the pool of actively translating ribosomes.     

SIRPB1 copy‐number polymorphism as candidate quantitative trait locus for impulsive‐disinhibited personality

Impulsive‐disinhibited personality (IDP) is a behavioral trait mainly characterized by seeking immediate gratification at the expense of more enduring or long‐term gains. This trait has a major role in the development of several disinhibitory behaviors and syndromes, including psychopathy, attention‐deficit and hyperactivity disorder, cluster‐B personality disorders, criminality and alcoholism. Available data consistently support a strong heritable component, accounting for 30–60% of the observed variance in personality traits. A genome‐wide analysis of copy‐number variants was designed to identify novel genetic pathways associated with the IDP trait, using a series of 261 male participants with maximized opposite IDP scores. Quantitative trait locus analysis of candidate copy‐number variants (CNVs) was conducted across the entire IDP continuum. Functional effects of associated variants were evaluated in zebrafish embryos. A common CNV mapping to the immune‐related gene SIRPB1 was significantly associated with IDP scores in a dose‐dependent manner (β = ?0.172, P < 0.017). Expression quantitative trait locus analysis of the critical region revealed higher SIRPB1 mRNA levels associated with the haplotype containing the deleted allele (P < 0.0007). Epigenetic marks highlighted the presence of two potential insulators within the deleted region, confirmed by functional assays in zebrafish embryos, which suggests that SIRPB1 expression rates are affected by the presence/absence of the insulator regions. Upregulation of SIRPB1 has been described in prefrontal cortex of patients with schizophrenia, providing a link between SIRPB1 and diseases involving disinhibition and failure to control impulsivity. We propose SIRPB1 as a novel candidate gene to account for phenotypic differences observed in the IDP trait.