Fluorescent (Au@SiO2)SiC Nanohybrids: Influence of Gold Nanoparticle Diameter and SiC Nanoparticle Surface Density

Gold@silica core–shell nanoparticles were prepared with various gold core diameters (ranging from 20 to 150 nm) and silica thicknesses (ranging from 10 to 30 nm). When the gold diameter is increased, the size dispersion became larger, leading to a broader plasmon band. Then, silicon carbide (SiC) nanoparticles were covalently immobilized onto silica to obtain hybrid (Au@SiO₂) SiC nanoparticles. The absorption properties of these hybrid nanoparticles showed that an excess of SiC nanoparticles in the dispersion can be identified by a strong absorption in the UV region. Compared to SiC reference samples, a blue shift of the fluorescence emission, from 582 to 523 nm, was observed, which was previously attributed to the strong surface modification of SiC when immobilized onto silica. Finally, the influence of several elaboration parameters (gold diameter, silica thickness, SiC concentration) on fluorescence enhancement was investigated. It showed that the highest enhancements were obtained with 10 nm silica thickness, low concentration of SiC nanoparticles, and surprisingly, with a 20-nm gold core diameter. This last result could be attributed to the broad plasmon band of big gold colloids. In this case, SiC emission strongly overlapped gold absorption, leading to possible quenching of SiC fluorescence by energy transfer.     

A Bayesian Meta-Analysis on Prevalence of Hepatitis B Virus Infection among Chinese Volunteer Blood Donors

Background

Although transfusion-transmitted infection of hepatitis B virus (HBV) threatens the blood safety of China, the nationwide circumstance of HBV infection among blood donors is still unclear.

Objectives

To comprehensively estimate the prevalence of HBsAg positive and HBV occult infection (OBI) among Chinese volunteer blood donors through bayesian meta-analysis.

Methods

We performed an electronic search in Pub-Med, Web of Knowledge, Medline, Wanfang Data and CNKI, complemented by a hand search of relevant reference lists. Two authors independently extracted data from the eligible studies. Then two bayesian random-effect meta-analyses were performed, followed by bayesian meta-regressions.

Results

5957412 and 571227 donors were identified in HBsAg group and OBI group, respectively. The pooled prevalence of HBsAg group and OBI group among donors is 1.085% (95% credible interval [CI] 0.859%∼1.398%) and 0.094% (95% CI 0.0578%∼0.1655%). For HBsAg group, subgroup analysis shows the more developed area has a lower prevalence than the less developed area; meta-regression indicates there is a significant decreasing trend in HBsAg positive prevalence with sampling year (beta = −0.1202, 95% −0.2081∼−0.0312).

Conclusion

Blood safety against HBV infection in China is suffering serious threats and the government should take effective measures to improve this situation.     

Circular RNA circABCC4 regulates lung adenocarcinoma progression via miR-3186-3p/TNRC6B axis

Lung adenocarcinoma (LUAD), a general kind of bronchogenic malignancy globally, is depicted as one of the most critical factors affecting human health severely. Featured with loop structure, circular RNA (circRNA) has been described as an essential regulator of multiple human malignancies. Nevertheless, knowledge concerning the regulatory function of circRNA in LUAD progression remains limited. Identified as a novel circRNA, circABCC4 has not been studied in LUAD as yet. This is the first time to probe into the underlying role of circABCC4 in LUAD. In this study, a notably elevated expression of circABCC4 was found in LUAD tissues and cells. Besides, circABCC4 is verified to be characterized with a circular structure in LUAD. Functional assays elucidated that knockdown of circABCC4 significantly impaired LUAD cell proliferation, migration as well as accelerated cell apoptosis. Molecular mechanism experiments later revealed that circABCC4 could bind with miR-3186-3p and miR-3186-3p was a tumor suppressor in LUAD. Moreover, TNRC6B was validated to combine with miR-3186-3p, and its expression was respectively negatively and positively regulated by miR-3186-3p and circABCC4 in LUAD. Final rescue experiments further delineated that TNRC6B upregulation partially restored circABCC4 downregulation-mediated effect on LUAD progression. In sum, circABCC4 regulates LUAD progression via miR-3186-3p/TNRC6B axis.     

The angiotensinogen gene M235T polymorphism and acute myocardial infarction risk: a meta-analysis of 22 studies

Angiotensinogen, one of the most important proteins in the renin–angiotensin system, plays a key role in the progress of coronary heart disease and myocardial infarction (MI). Many studies have investigated the association between angiotensinogen gene M235T polymorphism and MI risk, but the results were inconsistent. We performed a meta-analysis of 22 studies on M235T polymorphism and MI risk published before November 2012. This meta-analysis included a total of 4,606 MI cases and 4,918 controls. Overall, the per-allele odds ratio (OR) of the 235T variant for total MI risk was 1.04 (95 % CI 0.92–1.17). When a recessive model was evaluated, the OR was 1.06 (95 % CI 0.96–1.17) and under a dominant model, the OR was 0.96 (95 % CI 0.82–1.11). Under pairwise comparisons, non-significant associations were found between M235T polymorphism and MI risk (MT vs. MM, OR, 0.96, 95 % CI 0.87–1.06; TT vs. MM, OR, 1.03, 95 % CI 0.83–1.28). Subgroup analyses in the different ethnic groups and different control sources were performed and no significant association was found also. Based on the available evidence, no association between M235T polymorphism and MI risk was observed, even in the sub-analysis concerning different races and control sources. The direction of further research should focus not only on the simple relationship of M235T polymorphism and MI risk, but also on gene–gene and gene-environment interaction.     

Proposal of Ensifer psoraleae sp. nov., Ensifer sesbaniae sp. nov., Ensifer morelense comb. nov. and Ensifer americanum comb. nov

In a survey of rhizobia associated with the native legumes in Yunnan Province, China, seven and nine strains isolated from the root nodules of Psoralea corylifolia, Sesbania cannabina and Medicago lupulina were respectively classified into the novel genomic species groups I and II in the genus Ensifer (former Sinorhizobium) based on the sequence analyses of the 16S rRNA gene. Analyses of concatenated housekeeping genes (atpD, recA and glnII) further revealed that they were distinct lineages in the genus, and group I was most similar to Ensifer terangae and Ensifer garamanticus (both with 94.2% similarity), while group II was most similar to Ensifer adhaerens (94.0%). These groups could be distinguished from closely related species by DNA–DNA relatedness, MALID-TOF MS, cellular fatty acid profiles and a series of phenotypic characters. Therefore, two novel species were proposed: Ensifer psoraleae sp. nov. (seven strains, type strain CCBAU 65732^T = LMG 26835^T = HAMBI 3286^T) and Ensifer sesbaniae sp. nov. (nine strains, type strain CCBAU 65729^T = LMG 26833^T = HAMBI 3287^T). They had a DNA G + C mol% (T_m) of 58.9 and 60.4, respectively. Both of the type strains formed effective nodules on common bean (Phaseolus vulgaris) and their hosts of origin. In addition, the previously described species Sinorhizobium morelense and Sinorhizobium americanum were renamed as Ensifer morelense comb. nov. and Ensifer americanum comb. nov. according to the accumulated data from different studies.     

Sodium Taurocholate Cotransporting Polypeptide Mediates Woolly Monkey Hepatitis B Virus Infection of Tupaia Hepatocytes

Primary Tupaia hepatocytes (PTHs) are susceptible to woolly monkey hepatitis B virus (WMHBV) infection, but the identity of the cellular receptor(s) mediating WMHBV infection of PTHs remains unclear. Recently, sodium taurocholate cotransporting polypeptide (NTCP) was identified as a functional receptor for human hepatitis B virus (HBV) infection of primary human and Tupaia hepatocytes. In this study, a synthetic pre-S1 peptide from WMHBV was found to bind specifically to cells expressing Tupaia NTCP (tsNTCP) and it efficiently blocked WMHBV entry into PTHs; silencing of tsNTCP in PTHs significantly inhibited WMHBV infection. Ectopic expression of tsNTCP rendered HepG2 cells susceptible to WMHBV infection. These data demonstrate that tsNTCP is a functional receptor for WMHBV infection of PTHs. The result also indicates that NTCP''s orthologs likely act as a common cellular receptor for all known primate hepadnaviruses.     

Molecular Determinants of Hepatitis B and D Virus Entry Restriction in Mouse Sodium Taurocholate Cotransporting Polypeptide

Human hepatitis B virus (HBV) and its satellite virus, hepatitis D virus (HDV), primarily infect humans, chimpanzees, or tree shrews (Tupaia belangeri). Viral infections in other species are known to be mainly restricted at the entry level since viral replication can be achieved in the cells by transfection of the viral genome. Sodium taurocholate cotransporting polypeptide (NTCP) is a functional receptor for HBV and HDV, and amino acids 157 to 165 of NTCP are critical for viral entry and likely limit viral infection of macaques. However, the molecular determinants for viral entry restriction in mouse NTCP (mNTCP) remain unclear. In this study, mNTCP was found to be unable to support either HBV or HDV infection, although it can bind to pre-S1 of HBV L protein and is functional in transporting substrate taurocholate; comprehensive swapping and point mutations of human NTCP (hNTCP) and mNTCP revealed molecular determinants restricting mNTCP for viral entry of HBV and HDV. Remarkably, when mNTCP residues 84 to 87 were substituted by human counterparts, mNTCP can effectively support viral infections. In addition, a number of cell lines, regardless of their species or tissue origin, supported HDV infection when transfected with hNTCP or mNTCP with residues 84 to 87 replaced by human counterparts, highlighting the central role of NTCP for viral infections mediated by HBV envelope proteins. These studies advance our understanding of NTCP-mediated viral entry of HBV and HDV and have important implications for developing the mouse model for their infections.     

Mamu-B genes and their allelic repertoires in different populations of Chinese-origin rhesus macaques

Since rhesus monkeys of Chinese origin have gained greater utilization in recent years, it is urgent to investigate the major histocompatibility complex (MHC) immunogenetics of Chinese rhesus macaques. In this study, we identified 81 Mamu-B sequences using complementary DNA cloning and sequencing on a cohort of 58 rhesus monkeys derived from three local populations of China. Twenty of these Mamu-B alleles are novel and four of them represent new lineages. Although more alleles are shared among different populations than Mamu-A locus, the Mamu-B allelic repertoires found in these three populations of Chinese macaques are largely independent, which underscores the MHC polymorphism among different populations of Chinese rhesus macaques. Our results are an important addition to the limited MHC immunogenetic information available for rhesus macaques of Chinese origin.