印加孔雀草入侵生态风险评估及其管理措施

【目的】印加孔雀草为菊科一年生草本植物,原产南美洲,现已在我国多个地区发现,局部呈现生态危害。分析印加孔雀草生态适应性特点,可以有针对地提出其风险指标体系和判断标准,确定其危险级别。【方法】对印加孔雀草的分布、危害情况及生物学特性进行调查,定性分析其生态适应性特点,定量分析评估其生态风险,确定其危险级别。【结果】根据风险指标体系准则层的赋值,其中入侵性R_1为83,适应性R_2为88,扩散性R_3为65,危害性R_4为84,计算得出印加孔雀草风险值(R)=8061,属于具有危害性和侵入性的物种。【结论】印加孔雀草为具有危害性和侵入性的物种,应严格禁止引入。由于该植物已经传入我国,应采取必要的应急措施,开展检疫、监测和灭除,防止其传入其他还未发生的地区。     

黄顶菊入侵对不同生境地表土壤动物群落的影响

选择发生外来入侵植物黄顶菊(Flaveria bidentis)的林地、荒地和沟渠作为研究对象,探讨黄顶菊入侵对地表土壤动物群落的影响。调查采用陷阱法,于2012年4月26日—9月17日,每隔2周取样一次,3种生境共捕获地表土壤动物439515头,隶属3门7纲21目。蚁科在3种生境中均为优势类群,其余类群的相对多度较小。黄顶菊植株能够为蚁科、等足目、蟋蟀科和蜘蛛目等喜好阴凉湿润环境的地表土壤动物类群提供栖息地,从而对地表土壤动物群落结构及多样性产生影响;且该影响主要与黄顶菊自身的生长状况有关,在长势较弱的林地生境影响较小,而在长势较强的荒地和沟渠生境影响较大,这在黄顶菊生长盛期尤为明显。综上所述,黄顶菊入侵3种生境后可能通过影响微生境小气候从而改变地表土壤动物群落结构,并引起地表土壤动物多样性的升高。     

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.     

GM2 gangliosidoses in Spain: Analysis of the HEXA and HEXB genes in 34 Tay-Sachs and 14 Sandhoff patients

Acid α-glucosidase (GAA) is a lysosomal enzyme that hydrolyzes glycogen to glucose. Deficiency of GAA causes Pompe disease. Mammalian GAA is synthesized as a precursor of ~ 110,000 Da that is N-glycosylated and targeted to the lysosome via the M6P receptors. In the lysosome, human GAA is sequentially processed by proteases to polypeptides of 76-, 19.4-, and 3.9-kDa that remain associated. Further cleavage between R²⁰⁰ and A²⁰⁴ inefficiently converts the 76-kDa polypeptide to the mature 70-kDa form with an additional 10.4-kDa polypeptide. GAA maturation increases its affinity for glycogen by 7-10 fold. In contrast to human GAA, processing of bovine and hamster GAA to the 70-kDa form is more rapid. A comparison of sequences surrounding the cleavage site revealed human GAA contains histidine at 201 while other species contain hydrophobic amino acids at position 201 in the otherwise conserved sequence. Recombinant human GAA (rhGAA) containing the H201L substitution was expressed in 293 T cells by transfection. Pulse chase experiments in 293 T cells expressing rhGAA with or without the H201L substitution revealed rapid processing of rhGAA^H201L but not rhGAA^WT to the 70-kDa form. Similarly, when GAA precursor was endocytosed by human Pompe fibroblasts rhGAA^H201L but not rhGAA^WT was rapidly converted to the 70-kDa mature GAA. These studies indicate that the amino acid at position 201 influences the rate of conversion of 76-kDa GAA to 70-kDa GAA. The GAA sequence rather than the lysosomal protease environment explains the predominance of the 76-kDa form in human tissues.     

Nitric Oxide Inducing Function and Intracellular Movement of Chicken Interleukin-18 in Cultured Cells

To evaluate the characteristics of chicken interleukin-18 (ChIL-18) in different forms in vitro,the ChIL-18 full-length gene (ChIL-18-F) and the ChIL-18 presumed mature protein gene (ChIL-18-M) werecloned and inserted into the eukaryotic expression vector pCI,to construct recombinant pCI-ChIL-18-Fand pCI-ChIL-18-M.The recombinant plasmids were then transferred into chicken splenic lymphocytes(CSLs).Western blot showed that ChIL-18-F,with a molecular weight of 23.0 kDa,was produced in CSLstransfected by pCI-ChlL-18-F;ChIL-18-M,with a molecular weight of 19.5 kDa,was produced in CSLstransfected by pCI-ChIL-18-M.The nitric oxide (NO) level in the transfected CSLs and the culture mediumat different time points was further examined under confocal microscopy using 4.5-diaminofluoresceinstaining.The results showed that both pCI-ChIL-18-F and pCI-ChIL-18-M groups showed significantincrease in intracellular and extracellular NO production compared with pCI transfected control cells.Theseresults suggest that both ChIL-18-F and ChIL-18-M could stimulate NO secretion in CSLs.To characterizethe intracellular distribution of ChIL-18,ChIL-18-F and ChIL-18-M were each fused to the enhanced greenfluorescent protein gene,and expressed in Vero cells.The results showed that the ChIL-18-F tended to themembranous region in Vero cells,while ChIL-18-M did not.This indicates that the N-terminal 27 amino acidpeptide helped ChIL-18 target to Veto cell membranes.     

Phylogenetic positions of several amitochondriate protozoa——Evidence from phylogenetic analysis of DNA topoisomerase II

In the 1980s some special protozoa were gradually recognized: being eukaryotes, they possess some characteristics between prokaryotes and eukaryotes, for example, lack of eukaryotic organelle such as mi-tochondria, and even 70S ribosomes in some species, containing 16S, 23S rRNA like those of prokaryotes. These protozoa contain diplomonads (e.g. intestinal parasite Giardia), parabasalids (e.g. venereal disease pathogen Trichomonas), microsporidia (e.g. the human pathogen Encephalitozoon), a…     

Effects of drug relief hospital-based AIDS educational methods on drug users

INTRODUCTION Today, Acquired Immunodeficiency Syndrome (AIDS) has become a public health and social problem that has caused significant harm to the survival and development of humanbeings. Route of transmission of Human Im- munodeficiency Virus (HIV) is still predominantly through shared syringes by drug abusers. Currently, there is no efficient medicine, treatment or educational method to prevent HIV transmission in China. Intervention is prob- ably the best “vaccine” [1]. Despi…     

Residues Met~(76) and Gln~(79) in HLA-G α1 domain involved in KIR2DL4 recognition

INTRODUCTIONThe non-classical HLA class I antigen HLA-G is mainlyexpressed on extravillous cytotrophoblasts that invade de-ciduae in uterine pregnancy. Furthermore, HLA-G canmodulate the function of most immune component cellssuch as NK cells, T cells and…     

MSM and HIV/AIDS in China

INTRODUCTION The term MSM (men who have sex with men) was introduced into mainland China in 2000. Homosexuals, without identifying gender, were used previously to de- scribe MSM by authorities, the public and even professionals. The first confirmed MSM ca…     

小偃6号背景下黑麦遗传物质的荧光原位杂交分析

利用普通小麦(Triticum aestivum L.)“小偃6号”与黑麦(Secale cereale L.)品种“德国白粒”杂交,选育出“小偃6号”类型带有黑麦性状的种质材料。应用总基因组原位杂交(GISH)进行检测,在8份材料中探测到黑麦染色质的存在,其中附加系3个,代换系1个,易位系4个;进一步用荧光绿标记探针pSc119.2及荧光红标记探针pAs1的双色荧光原位杂交(FISH)技术,对其中部分品系的染色体组成进行分析鉴定,结果表明:易位系BC116-1是1RS/1BL小麦/黑麦易位系,BC152-1是涉及一条1B染色体的1RS/1BL易位系, 代换系BC97-2是2R(2D)二体代换系;附加系BC122-3附加了一条6R黑麦染色体,一条6B染色体的长臂缺失。同时,对连续的总基因组原位杂交和双色荧光原位杂交技术在小麦育种中的应用进行了讨论。