Nationwide molecular surveillance of pandemic H1N1 influenza A virus genomes: Canada, 2009

Background

In April 2009, a novel triple-reassortant swine influenza A H1N1 virus (“A/H1N1pdm”; also known as SOIV) was detected and spread globally as the first influenza pandemic of the 21^st century. Sequencing has since been conducted at an unprecedented rate globally in order to monitor the diversification of this emergent virus and to track mutations that may affect virus behavior.

Methodology/Principal Findings

By Sanger sequencing, we determined consensus whole-genome sequences for A/H1N1pdm viruses sampled nationwide in Canada over 33 weeks during the 2009 first and second pandemic waves. A total of 235 virus genomes sampled from unique subjects were analyzed, providing insight into the temporal and spatial trajectory of A/H1N1pdm lineages within Canada. Three clades (2, 3, and 7) were identifiable within the first two weeks of A/H1N1pdm appearance, with clades 5 and 6 appearing thereafter; further diversification was not apparent. Only two viral sites displayed evidence of adaptive evolution, located in hemagglutinin (HA) corresponding to D222 in the HA receptor-binding site, and to E374 at HA2-subunit position 47. Among the Canadian sampled viruses, we observed notable genetic diversity (1.47×10⁻³ amino acid substitutions per site) in the gene encoding PB1, particularly within the viral genomic RNA (vRNA)-binding domain (residues 493–757). This genome data set supports the conclusion that A/H1N1pdm is evolving but not excessively relative to other H1N1 influenza A viruses. Entropy analysis was used to investigate whether any mutated A/H1N1pdm protein residues were associated with infection severity; however no virus genotypes were observed to trend with infection severity. One virus that harboured heterozygote coding mutations, including PB2 D567D/G, was attributed to a severe and potentially mixed infection; yet the functional significance of this PB2 mutation remains unknown.

Conclusions/Significance

These findings contribute to enhanced understanding of Influenza A/H1N1pdm viral dynamics.     

大连市中老年人肠道菌群构成情况的调查

【摘 要】 目的 通过对大连市市区部分正常中老年人肠道菌群情况的检查结果统计分析,为该市正常中老年人肠道菌群正常指标提供参考依据。方法 取不同年龄段的老年人粪便,分别采用显微镜检查和微生物培养方法,进行肠道菌群分析。选择涂片均匀的大便标本,用油镜计数500个细菌,计算革兰阳性菌和革兰阴性菌的比例。结果 正常中年人肠道菌群具体比率情况报告如下:革兰阴性杆菌：55.5±5.7,革兰阳性球菌19.9±5.8,革兰阳性杆菌17.2±5.0;老年人的肠道菌群具体比率情况报告如下：革兰阴性杆菌69.5±6.4,革兰阳性球菌13.1±4.9,革兰阳性杆菌14.9±5.9,真菌孢子0.1±0.1。经过粪便标本菌群分析,老年组的双歧杆菌数量明显下降。结论 年龄等因素对肠道菌群有影响,临床诊断与检验应考虑不同年龄层次的人群。     

蜜环菌饮料对机体活性的调节作用研究

为了研究蜜环菌饮料对小鼠机体功能的影响,采用环磷酰胺(CY)造模法制作小鼠免疫抑制模型,通过灌胃不同剂量蜜环菌饮料,研究对小鼠机体免疫功能的影响,同时通过测定实验小鼠肠道中细菌总数、大肠杆菌数、乳酸菌和双歧杆菌数等,分析不同剂量的蜜环菌饮料对肠道菌相的影响,最后对小鼠进行了急性毒性试验研究,以检测饮料有无毒副作用。结果表明蜜环菌饮料可明显提高小鼠脾脏和胸腺指数,促进脾脏及胸腺的发育,促进巨噬细胞的吞噬活性,明显增强小鼠的免疫功能,同时还能促进小鼠肠道有益菌的生长,改善肠道微生物区系环境,饮料没有对小鼠产生任何的毒副作用。证明蜜环菌饮料不仅增强机体免疫功能,同时还增强肠道功能,保持和促进机体健康。     

Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in China

Environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from China, we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.     

Increased T cell proliferative responses to islet antigens identify clinical responders to anti-CD20 monoclonal antibody (rituximab) therapy in type 1 diabetes

Type 1 diabetes mellitus is believed to be due to the autoimmune destruction of β-cells by T lymphocytes, but a single course of rituximab, a monoclonal anti-CD20 B lymphocyte Ab, can attenuate C-peptide loss over the first year of disease. The effects of B cell depletion on disease-associated T cell responses have not been studied. We compare changes in lymphocyte subsets, T cell proliferative responses to disease-associated target Ags, and C-peptide levels of participants who did (responders) or did not (nonresponders) show signs of β-cell preservation 1 y after rituximab therapy in a placebo-controlled TrialNet trial. Rituximab decreased B lymphocyte levels after four weekly doses of mAb. T cell proliferative responses to diabetes-associated Ags were present at baseline in 75% of anti-CD20- and 82% of placebo-treated subjects and were not different over time. However, in rituximab-treated subjects with significant C-peptide preservation at 6 mo (58%), the proliferative responses to diabetes-associated total (p = 0.032), islet-specific (p = 0.048), and neuronal autoantigens (p = 0.005) increased over the 12-mo observation period. This relationship was not seen in placebo-treated patients. We conclude that in patients with type 1 diabetes mellitus, anti-B cell mAb causes increased proliferative responses to diabetes Ags and attenuated β-cell loss. The way in which these responses affect the disease course remains unknown.     

Upregulation of FIk-1 by bFGF via the ERK pathway is essential for VEGF-mediated promotion of neural stem cell proliferation

Neural stem cells (NSCs) constitute the cellular basis for embryonic brain development and neurogenesis.The processis regulated by NSC niche including neighbor cells such as vascular and glial cells.Since both vascular and glial cellssecrete vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF),we assessed the effect ofVEGF and bFGF on NSC proliferation using nearly homogeneous NSCs that were differentiated from mouse embryonicstem cells.VEGF alone did not have any significant effect.When bFGF was added,however,VEGF stimulated NSCproliferation in a dose-dependent manner,and this stimulation was inhibited by ZM323881,a VEGF receptor (Flk-1)-specific inhibitor.Interestingly,ZM323881 also inhibited cell proliferation in the absence of exogenous VEGF,suggestingthat VEGF autocrine plays a role in the proliferation of NSCs.The stimulatory effect of VEGF on NSC proliferationdepends on bFGF,which is likely due to the fact that expression of Flk-1 was upregulated by bFGF via phosphoryla-tion of ERK1/2.Collectively,this study may provide insight into the mechanisms by which mieroenvironmental nichesignals regulate NSCs.     

HSC的活化、增殖与TGF-β1及其Ⅰ型受体在中晚期纤维化肝组织中的改变及护肝片对其的影响

目的 探讨护肝片对中、晚期纤维化大鼠肝组织肝星状细胞（HSC）的活化与增殖及转化生长因子-β1（TGF-β1）及其工型受体（TβRⅠ）表达的影响。方法 采用12．5％CCh诱导的大鼠肝纤维化模型,自造模之日起,大鼠分组灌胃给药（护肝片921mg·kg^-1）或溶媒,每日一次,直至8或13周末,分别处死动物,取左叶肝组织石蜡包埋,制作组织芯片,免疫组化S-P法检测大鼠肝组织α-平滑肌肌动蛋白（α-SMA）、TGF-β1及TβRⅠ蛋白的表达,并用Meta Morph图像分析系统计数α-SMA阳性细胞数、对TGF-β1。及TβRⅠ蛋白表达量进行定量分析。结果 1．模型复制8周和13周,模型组的肝损伤及其纤维化分级均明显高于正常组（P〈0．01）,护肝片组的肝损伤及其纤维化分级均轻于模型组。2．模型复制8周和13周,模型组活化的HSC（即α-SMA阳性细胞）数量较正常组明显增多、TGF-β1及TβRⅠ蛋白的表达较正常组明显增强（P〈0．01）;3．护肝片显著抑制8、13周纤维化肝组织HSC的活化与增殖和TGF-β1及TβRⅠ蛋白的表达（P〈0．01）。结论 抑制HSC的活化与增殖和TGF-β1及TβRⅠ的表达可能是护肝片抗肝纤维化作用的靶点之一。     

江苏东台野生草本植物多样性及其与环境因子的关系

基于2019年3月(春季)、6月(夏季)和9月(秋季)进行的50个调查样点和247个1 m × 1 m的草本调查样方数据, 探究了东台市野生草本植物多样性现状及其与环境因子的关系。通过R语言的vegan程序包计算各调查样点的物种多样性指数。同时结合相关环境因子, 运用R语言的ggplot2、spgwr、multcomp和dplyr等程序包, 通过一元线性回归模型和地理加权回归模型探讨了物种多样性与环境因子的关系。统计分析结果表明: 东台市共计有野生草本植物178种, 隶属于47科134属。其中, 一年生和二年生草本植物共计有90种, 占总数的50.56%; 多年生草本植物共计有88种, 占总数的49.44%。物种丰富度指数(R)随年均温度(MAT)的上升呈极显著性的递增趋势(P < 0.01), 同时随年均降水量(MAP)的上升呈显著性的递增趋势(P < 0.05)。Shannon-Wiener多样性指数(H)随年均温度(MAT)的上升呈显著性的递增趋势(P < 0.05)。年均温度(MAT)和年均降水量(MAP)对东台市野生植物多样性的影响较大, 二者对野生草本植物物种丰富度差异的解释率可达41.80%, 其中年均温度解释率为25.38%, 年均降水量解释率为12.76%, 而人口密度(PD)对物种多样性的影响较小。研究结果表明东台市野生草本植物物种多样性受水热条件影响较大, 主要由热量动能和水分状况共同决定, 进一步验证了水分-能量动态假说。     

Circadian gene variants and susceptibility to type 2 diabetes: a pilot study

Background

Disruption of endogenous circadian rhythms has been shown to increase the risk of developing type 2 diabetes, suggesting that circadian genes might play a role in determining disease susceptibility. We present the results of a pilot study investigating the association between type 2 diabetes and selected single nucleotide polymorphisms (SNPs) in/near nine circadian genes. The variants were chosen based on their previously reported association with prostate cancer, a disease that has been suggested to have a genetic link with type 2 diabetes through a number of shared inherited risk determinants.

Methodology/Principal Findings

The pilot study was performed using two genetically homogeneous Punjabi cohorts, one resident in the United Kingdom and one indigenous to Pakistan. Subjects with (N = 1732) and without (N = 1780) type 2 diabetes were genotyped for thirteen circadian variants using a competitive allele-specific polymerase chain reaction method. Associations between the SNPs and type 2 diabetes were investigated using logistic regression. The results were also combined with in silico data from other South Asian datasets (SAT2D consortium) and white European cohorts (DIAGRAM+) using meta-analysis. The rs7602358G allele near PER2 was negatively associated with type 2 diabetes in our Punjabi cohorts (combined odds ratio [OR] = 0.75 [0.66–0.86], p = 3.18×10⁻⁵), while the BMAL1 rs11022775T allele was associated with an increased risk of the disease (combined OR = 1.22 [1.07–1.39], p = 0.003). Neither of these associations was replicated in the SAT2D or DIAGRAM+ datasets, however. Meta-analysis of all the cohorts identified disease associations with two variants, rs2292912 in CRY2 and rs12315175 near CRY1, although statistical significance was nominal (combined OR = 1.05 [1.01–1.08], p = 0.008 and OR = 0.95 [0.91–0.99], p = 0.015 respectively).

Conclusions/significance

None of the selected circadian gene variants was associated with type 2 diabetes with study-wide significance after meta-analysis. The nominal association observed with the CRY2 SNP, however, complements previous findings and confirms a role for this locus in disease susceptibility.