Downregulation of Kinesin Spindle Protein Inhibits Proliferation,Induces Apoptosis and Increases Chemosensitivity in Hepatocellular Carcinoma Cells

Background: Kinesin spindle protein (KSP) plays a critical role in mitosis. Inhibition of KSP function leads to cell cycle arrest at mitosis and ultimately to cell death. The aim of this study was to suppress KSP expression by specific small-interfering RNA (siRNA) in Hep3B cells and evaluate its anti-tumor activity. Methods: Three siRNA targeting KSP (KSP-siRNA #1-3) and one mismatched-siRNA (Cont-siRNA) were transfected into cells. Subsequently, KSP mRNA and protein levels, cell proliferation, and apoptosis were examined in both Hep3B cells and THLE-3 cells. In addition, the chemosensitivity of KSP-siRNA-treated Hep3B cells with doxorubicin was also investigated using cell proliferation and clonogenic survival assays. Results: The expression of endogenous KSP at both mRNA and protein levels in Hep3B cells was higher than in THLE-3 cells. In Hep3B cells, KSP-siRNA #2 showed a further downregulation of KSP as compared to KSP-siRNA #1 or KSP-siRNA #3. It also exhibited greater suppression of cell proliferation and induction of apoptosis than KSP-siRNA #1 or KSP-siRNA #3; this could be explained by the significant downregulation of cyclin D1, Bcl-2, and survivin. In contrast, KSP-siRNAs had no or lower effects on KSP expression, cell proliferation and apoptosis in THLE-3 cells. We also noticed that KSP-siRNA transfection could increase chemosensitivity to doxorubicin in Hep3B cells, even at low doses compared to control. Conclusion: Reducing the expression level of KSP, combined with drug treatment, yields promising results for eradicating hepatocellular carcinoma (HCC) cells in vitro. This study opens a new direction for liver cancer treatment. Key Words: Apoptosis, Chemosensitivity, Doxorubicin, Hepatocellular carcinoma (HCC) cells, Kinesin spindle protein (KSP)     

Genetic characterization of chicken anemia viruses newly isolated from diseased chicks in Japan in 2020

In this study, a total of nine chicken samples obtained from two broiler flocks in Oita and Tottori prefectures in 2020 were examined for Chicken anemia virus (CAV) infection. The samples were collected from clinically suspected flocks and diseased chickens. The CAV genome was detected in all nine samples tested by real-time PCR. Phylogenetic analyses and sequence comparisons of the full-length VP1 gene sequences indicated that all the Japanese CAV strains obtained in this study formed a similar cluster of genotype III and shared high nucleotide (99.62–100%) identity. The current Japanese CAV strains were closely related to Chinese CAV strains but not related to vaccine strains. One positive selection site of VP1 was detected among the Japanese CAV strains.     

Arcobacter, what is known and unknown about a potential foodborne zoonotic agent!

Since the introduction of the genus Arcobacter in 1991, the association of Arcobacter butzleri, Arcobacter cryaerophilus and Arcobacter skirrowii with humans and animals has been clearly established. These bacteria have been detected world wide in products of animal origin and in healthy animals as well as in surface water. A fourth species Arcobacter cibarius was recently discovered on chicken carcasses. Although evidence was found for the connection of Arcobacter spp. with human and animal illness, Arcobacter spp. can be pathogens, opportunistic pathogens and commensals. Their potential as zoonotic foodborne and waterborne agents, the routes of transmission and the pathogenic mechanisms of these bacteria are largely unknown. Production of toxins or other virulence factors has not been demonstrated but adhesive and/or invasive properties were apparent. Antibiotic resistance is present in Arcobacter strains to significant levels. The tools to genetically access Arcobacter-like transformation of strains, construction of mutants are not yet available. Nor have genes (i.e. potential virulence factors) been cloned, expressed and characterized in other host organisms. Therefore those interested in the microbiology of these organisms eagerly await publication of the complete nucleotide sequence of the Arcobacter genome. The abundant presence of four Arcobacter species in foods of animal origin and the recovery of these bacteria from surface and drinking water suggest an important role of these bacteria as foodborne or waterborne agent and possibly as zoonotic agent.     

竹柳枝桠材重组木的研制

以幼龄竹柳枝桠材为原料,通过对竹柳枝桠材酸碱性、密度、干缩性、表面接触角以及密度、施胶量对竹柳重组木物理力学性能的影响进行研究。结果表明,竹柳枝桠材的pH为6．43～6．46,呈弱酸性,酸碱缓冲容量为34．63～38．94 mL,全干干缩率为1．86,气干干缩率为1．91;利用表面张力测量仪测得,竹柳枝桠材外表面MUF接触角为54．52°,内表面为37．27°。在板材密度0．9 g／cm3、三聚氰胺改性脲醛树脂（MUF）施胶量14％、热压温度160℃、加压时间20 min、木束含水率6％条件下制得的竹柳重组木弹性模量为12948．68 MPa,达到GB／T 4897．7—2003《刨花板》的要求;静曲强度为105．08 MPa,内结合强度为2．07 MPa,2 h吸水厚度膨胀率为3．49％,其值均达到了LY／T 1984—2011《重组木地板》的要求。SEM图像表明MUF 压制的竹柳重组木的管孔被压缩成椭圆形,但细胞壁本身并没有被压溃,仍然保持了其完整性;红外光谱仪测试结果表明,竹柳的纤维素和半纤维素均与胶黏剂发生反应,存在化学键的结合。     

越南农业生产概况

概述了越南的地理位置及气候条件,指出根据越南地形、土壤和气候条件,可将越南农业划分为红河平原、北部丘陵山区、中山部及中部沿海地区、西原地区、东南部、九龙江平原6个生态区,并介绍了越南农业结构以及玉米、水稻、木薯、红薯、甘蔗、花生、大豆、茶叶、咖啡、橡胶、胡椒、腰果、椰子等主要农作物的生产概况。     

Molecular characterization of two Bangladeshi infectious bursal disease virus isolates using the hypervariable sequence of VP2 as a genetic marker

Two Bangladeshi infectious bursal disease virus (IBDV) isolates collected in 2007, termed GB1 and GB3, were subjected to comparative sequencing and phylogenetic analyses. Sequence analysis of a 474-bp hypervariable region in the VP2 gene revealed that among four major amino acid substitutions observed in the strains, two were unique to GB1 and GB3 (Ser217Leu and Ala270Thr) while one substitution was only found in GB1 (Asn299Ser). Among IBDVs from Bangladesh including GB1 and GB3, the rate of identity and homology was around 97~99%. The amino acid sequences of GB1 and GB3 differ from those of previous Bangladeshi IBDV isolates and contain amino acid substitutions Pro222Ala and Asn299Ser (in GB3 only). Phylogenetic analysis revealed that GB1 and GB3 are grouped with other very virulent IBDVs of European and American origin in contrast to two previously isolated Bangladeshi IBDV strains (GenBank accession Nos. {"type":"entrez-nucleotide","attrs":{"text":"AF362776","term_id":"14582985","term_text":"AF362776"}}AF362776 and {"type":"entrez-nucleotide","attrs":{"text":"AF260317","term_id":"13957666","term_text":"AF260317"}}AF260317), which belong to the Asian group. It was concluded that GB1 and GB3 belong to a very virulent group of IBDVs. However, amino acid sequences of GB1 and GB3 differ from those of the other Bangladeshi IBDVs by one or two amino acids encoded in the hypervariable region of the VP2 gene.     

Non‐Typhoidal Salmonella Colonization in Chickens and Humans in the Mekong Delta of Vietnam

Salmonellosis is a public health concern in both the developed and developing countries. Although the majority of human non‐typhoidal Salmonella enterica (NTS) cases are the result of foodborne infections or person‐to‐person transmission, NTS infections may also be acquired by environmental and occupational exposure to animals. While a considerable number of studies have investigated the presence of NTS in farm animals and meat/carcasses, very few studies have investigated the risk of NTS colonization in humans as a result of direct animal exposure. We investigated asymptomatic NTS colonization in 204 backyard chicken farms, 204 farmers and 306 matched individuals not exposed to chicken farming, in southern Vietnam. Pooled chicken faeces, collected using boot or handheld swabs on backyard chicken farms, and rectal swabs from human participants were tested. NTS colonization prevalence was 45.6%, 4.4% and 2.6% for chicken farms, farmers and unexposed individuals, respectively. Our study observed a higher prevalence of NTS colonization among chicken farmers (4.4%) compared with age‐, sex‐ and location‐ matched rural and urban individuals not exposed to chickens (2.9% and 2.0%). A total of 164 chicken NTS strains and 17 human NTS strains were isolated, and 28 serovars were identified. Salmonella Weltevreden was the predominant serovar in both chickens and humans. NTS isolates showed resistance (20–40%) against tetracycline, chloramphenicol, sulfamethoxazole‐trimethoprim and ampicillin. Our study reflects the epidemiology of NTS colonization in chickens and humans in the Mekong delta of Vietnam and emphasizes the need of larger, preferably longitudinal studies to study the transmission dynamics of NTS between and within animal and human host populations.     

越南水稻黄矮病毒多克隆血清抗体的制备

[目的]制备用于检测水稻黄矮病毒(RYSV)的多克隆抗体,为水稻和黑尾叶蝉上的病毒诊断提供技术支持.[方法]利用两种不同来源的RYSV抗原免疫家兔,一种是从受感染的水稻病叶组织纯化获得RYSV病毒粒子;另一种是从越南RYSV分离株克隆出完整N蛋白编码基因,然后将其连接至pET-28a载体上,在大肠杆菌Rosetta(DE3)菌株中进行诱导表达获得N蛋白抗原.其中,N蛋白抗原又以两种形式(洗脱纯化N蛋白和N蛋白条带聚丙烯酰胺切片匀浆)对家兔进行免疫.最后,采用PTA-ELISA分析评估家兔抗体血清(多克隆抗体)对水稻叶片和黑尾叶蝉RYSV的特异性和敏感性.[结果]分离自越南RYSV分离株的N基因由1542个核苷酸组成,与来自我国和日本RYS分离株N基因序列进行比对,其核苷酸序列同源性分别为98.1%和97.9%,对应的推导氨基酸序列同源性为83.4%和99.4%.以RYSV病毒粒子、洗脱纯化N蛋白和N蛋白条带聚丙烯酰胺切片匀浆3种抗原免疫家兔获得的多克隆抗体均能有效检测出水稻植株中的RYSV,其中,感病植株的OD405分别为1.449、2.337和1.649,健康植株的OD405分别为0.375、0.294和0.283.PTA-ELISA检测结果表明,获得的多克隆抗体能从单个带病毒黑尾叶蝉中检测出RYSV,且该结论在RT-PCR检测中得到进一步验证.[结论]制备获得的多克隆抗体对RYSV具有较高特异性和敏感性,可用于水稻和黑尾叶蝉上的病毒诊断,同时表明以含有病毒植物蛋白的聚丙烯酰胺切片直接注射免疫模型动物制备多克隆抗体具有可行性.     

Incorporation of rice straw mitigates CH4 and N2O emissions in water saving paddy fields of Central Vietnam

This study evaluated the effects of rice straw and water regimes on CH₄ and N₂O emissions from paddy fields for two rice growing seasons (summer 2014 and spring 2015). Water regimes included alternating wet–dry irrigation (AWD) maintained at three levels (–5 cm, – 10 cm and –15 cm) in comparison to continuous flooding irrigation (CF). Rice straw (5 t ha^–1) was incorporated into the top soil (0 – 15 cm), distributed and burned in situ. Results showed that using burned in situ rice straw was found to reduce seasonal cumulative CH₄ emission (24–34% in summer; 18–28% in spring), N₂O emission (21–32% in summer; 22–29% in spring) and lower rice yield (8–9%) than rice straw incorporation into top soil. AWD methods reduced the amount of CH₄ production (22.6–41.5%) and increased N₂O emission (25–26%) without any decrease in rice yield. Rice straw incorporation into the top soil with AWD had higher water productivity (23–37%) than rice straw when burned in situ with CF. The results conclude that AWD and rice straw management can be employed as mitigation strategy for CH₄ and N₂O emissions from paddy fields in Central Vietnam.