Identification and Effect Decomposition of Risk Factors for Brucella Contamination of Raw Whole Milk in China

Background

Lack of clear risk factor identification is the main reason for the persistence of brucellosis infection in the Chinese population, and there has been little assessment of the factors contributing to Brucella contamination of raw whole milk. The purpose of this study was to identify risk factors affecting Brucella contamination of raw milk, and to evaluate effective measures for disease reduction in order to determine preventive strategies.

Methods and Findings

A nationwide survey was conducted and samples were obtained from 5211 cows corresponding to 25 sampling locations throughout 15 provinces in China. The prevalence of Brucella in the raw milk samples averaged 1.07% over the 15 Chinese provinces, while the prevalence of positive areas within these regions ranged from 0.23–3.84% among the nine provinces with positive samples. The survey examined factors that supposedly influence Brucella contamination of raw whole milk, such as management style, herd size, abortion rate, hygiene and disease control practices. A binary logistic regression analysis was carried out to determine the association between risk factors for Brucella and contamination of milk samples. Furthermore, a relative effect decomposition study was conducted to determine effective strategies for reducing the risk of Brucella contamination of raw whole milk. Our data indicate that disease prevention and control measures, abortion rate, and animal polyculture are the most important risk factors. Meanwhile, culling after quarantine was identified as an effective protective measure in the current Chinese dairy situation.

Conclusions

These results indicate that, although there is a low risk of contamination of milk with Brucella nationwide in China, there are individual regions where contamination is a significant problem. Controlling three factors–culling after quarantine, maintaining a low abortion rate, and avoiding mixing groups of cattle and small ruminants–could effectively reduce the risk of Brucella contamination of raw whole milk.     

Design,synthesis, quantum chemical studies and biological activity evaluation of pyrazole–benzimidazole derivatives as potent Aurora A/B kinase inhibitors

Novel pyrazole–benzimidazole derivatives have been designed and synthesized. The entire target compounds were determined against cancer cell lines U937, K562, A549, LoVo and HT29 and were screened for Aurora A/B kinase inhibitory activity in vitro. The compounds 7a, 7b, 7i, 7k and 7l demonstrated significant cancer cell lines and Aurora A/B kinase inhibitory activities. Molecular modeling studies suggested the derivatives have bound in the active site of Aurora A kinase through the formation of four hydrogen bonds. Quantum chemical studies were carried out on these compounds to understand the structural features essential for activity. The cellular activity of 7k was also tested by immunofluorescence.     

猪肥胖基因cDNA的克隆与分析

肥胖基因（ａｂ）是近年刚被克隆的新基因,该基因产物Ｌｅｐｔｉｎ是反映体内脂肪含量和调节体重的重信号因子,首次报道猪ｏｂ基因全长序列,并对不同种物ｏｂ基因的同源性进行了比较,以λＵｎｉ－ＺＡＰ＾ＴＭ为载体构建了猪脂肪ｃＤＮＡ文库,根据已知的人和鼠ｏｂ基因序列设计ＰＣＲ引物,利用ＰＣＲ法筛选猪脂肪ｃＤＮＡ文库,并用ＲＴ－ＰＣＲ从脂肪ＲＮＡ中扩增的３６６ｂｐ猪ｏｂ基因片段作探针,获得了全长３２７７ｂｐ的     

Multilocus typing of Cryptosporidium spp. and Giardia duodenalis from non-human primates in China

Non-human primates (NHPs) are commonly infected with Cryptosporidium spp. and Giardia duodenalis. However, molecular characterisation of these pathogens from NHPs remains scarce. In this study, 2,660 specimens from 26 NHP species in China were examined and characterised by PCR amplification of 18S rRNA, 70 kDa heat shock protein (hsp70) and 60 kDa glycoprotein (gp60) gene loci for Cryptosporidium; and 1,386 of the specimens by ssrRNA, triosephosphate isomerase (tpi) and glutamate dehydrogenase (gdh) gene loci for Giardia. Cryptosporidium was detected in 0.7% (19/2660) specimens of four NHP species including rhesus macaques (0.7%), cynomolgus monkeys (1.0%), slow lorises (10.0%) and Francois’ leaf monkeys (6.7%), belonging to Cryptosporidium hominis (14/19) and Cryptosporidium muris (5/19). Two C. hominis gp60 subtypes, IbA12G3 and IiA17 were observed. Based on the tpi locus, G. duodenalis was identified in 2.2% (30/1,386) of specimens including 2.1% in rhesus macaques, 33.3% in Japanese macaques, 16.7% in Assam macaques, 0.7% in white-headed langurs, 1.6% in cynomolgus monkeys and 16.7% in olive baboons. Sequence analysis of the three targets indicated that all of the Giardia-positive specimens belonged to the zoonotic assemblage B. Highest sequence polymorphism was observed at the tpi locus, including 11 subtypes: three known and eight new ones. Phylogenetic analysis of the subtypes showed that most of them were close to the so-called subtype BIV. Intragenotypic variations at the gdh locus revealed six types of sequences (three known and three new), all of which belonged to so-called subtype BIV. Three specimens had co-infection with C. hominis (IbA12G3) and G. duodenalis (BIV). The presence of zoonotic genotypes and subtypes of Cryptosporidium spp. and G. duodenalis in NHPs suggests that these animals can potentially contribute to the transmission of human cryptosporidiosis and giardiasis.     

中国黑缘蝽属新种记述(半翅目:缘蝽科)

中国黑缘蝽属(Hygia Uhler)为缘蝽科缘蝽亚科中较大的属,体均为黑色,常具黄色或褐黄色斑。截止到目前已记载19种,现由近年来采集的标本中又发现7新种,分属于两个亚属:黑缘蝽亚属Hygia Uhler及沟缘蝽亚属Colpura Bergroth,现描述如下。文内所用量度单位均为毫米。模式标本除注明者外,均存放南开大学生物系。     

FLZ Alleviates the Memory Deficits in Transgenic Mouse Model of Alzheimer’s Disease via Decreasing Beta-Amyloid Production and Tau Hyperphosphorylation

Alzheimer’s disease (AD) is the most common cause of dementia worldwide and mainly characterized by the aggregated β-amyloid (Aβ) and hyperphosphorylated tau. FLZ is a novel synthetic derivative of natural squamosamide and has been proved to improve memory deficits in dementia animal models. In this study, we aimed to investigate the mechanisms of FLZ’s neuroprotective effect in APP/PS1 double transgenic mice and SH-SY5Y (APPwt/swe) cells. The results showed that treatment with FLZ significantly improved the memory deficits of APP/PS1 transgenic mice and decreased apoptosis of SH-SY5Y (APPwt/swe) cells. FLZ markedly attenuated Aβ accumulation and tau phosphorylation both in vivo and in vitro. Mechanistic study showed that FLZ interfered APP processing, i.e., FLZ decreased β-amyloid precursor protein (APP) phosphorylation, APP-carboxy-terminal fragment (APP-CTF) production and β-amyloid precursor protein cleaving enzyme 1 (BACE1) expression. These results indicated that FLZ reduced Aβ production through inhibiting amyloidogenic pathway. The mechanistic study about FLZ’s inhibitory effect on tau phosphorylation revealed t the involvement of Akt/glycogen synthase kinase 3β (GSK3β) pathway. FLZ treatment increased Akt activity and inhibited GSK3β activity both in vivo and in vitro. The inhibitory effect of FLZ on GSK3β activity and tau phosphorylation was suppressed by inhibiting Akt activity, indicating that Akt/GSK3β pathway might be the possible mechanism involved in the inhibitory effect of FLZ on tau hyperphosphorylation. These results suggested FLZ might be a potential anti-AD drug as it not only reduced Aβ production via inhibition amyloidogenic APP processing pathway, but also attenuated tau hyperphosphoylation mediated by Akt/GSK3β.     

人胃癌BGC-823细胞中去甲斑蝥素抑癌作用机理的蛋白质组学研究

去甲斑蝥素是我国自行研制的抗肿瘤药物,在临床上主要用于消化道肿瘤的治疗．实验表明,去甲斑蝥素可引起人胃癌BGC-823细胞发生 M期阻滞及细胞凋亡．进一步利用双向电泳和质谱技术,筛选出了去甲斑蝥素抑癌作用相关蛋白．研究显示,线粒体热休克蛋白CH60、线粒体ATP合酶d亚单位、内质网葡萄糖调节蛋白GRP78、线粒体Hsp70的辅助因子GRPE1、SH3L3以及染色质组装因子1小亚基RBBP4参与了去甲斑蝥素的抑癌作用．研究提示,去甲斑蝥素可能通过促进线粒体热休克蛋白及p53的表达进而激活caspase-3依赖的凋亡通路,并且去甲斑蝥素在引发内质网协迫之后,可通过抑制胞外信号调节激酶(extracellular signal regulated kinase, ERK)的活性促进肿瘤细胞的凋亡．进一步分析了去甲斑蝥素与线粒体ATP合酶抑制剂寡霉素A的联合用药对人胃癌细胞生长的影响,结果表明,联合用药的抑瘤效果比单独用药的抑瘤效果显著,提示去甲斑蝥素可能通过抑制线粒体ATP合酶功能抑制BGC-823生长．上述结果为优化去甲斑蝥素的联合用药方案提供了新线索．     

鲨鱼软骨血管生成抑制因子的纯化和功能

以中国东海鲸鲨软骨为原料,通过盐抽提、丙酮分级沉淀、离子交换层折、分子筛层析、高效液相色谱等步骤,获得鲨鱼软骨血管生成抑制因子－Ｉ（ｓｈａｒｋ ｃａｒｔｉｌｇａｅ ａｎｇｉｏｇｅｎｅｓｉｓ ｉｎｈｉｂｉｔｏｒｙ ｆａｃｔｏｒ－Ｉ,ＳＣＡＩＦ－Ｉ）,对其分子量、抑制血管生成及抑制肿瘤生长活性进行了研究。结果显示ＳＣＡＩＦ－Ｉ分子量１８ｋＤ,在细胞和整体水平上显著抑制新血管生成,显著抑制小鼠肿瘤的生长     

关节镜联合富血小板血浆对膝关节半月板损伤患者膝关节功能和生活质量的影响

目的:探讨关节镜联合富血小板血浆对膝关节半月板损伤患者膝关节功能和生活质量的影响。方法:选取2017年12月-2019年9月期间我院收治的膝关节半月板损伤患者80例,根据随机数字表法分为对照组(n=40)和研究组(n=40),对照组予以关节镜下修整手术治疗,研究组在对照组基础上联合富血小板血浆治疗,比较两组患者优良率、生活质量及视觉模拟评分量表(VAS)、Lysholm评分量表、美国西安大略和麦克马斯特大学关节炎指数(WOMAC)评分。记录两组治疗期间不良反应情况。结果:研究组治疗后3个月的膝关节功能优良率高于对照组(P0.05)。两组治疗前、治疗后1个月、治疗后3个月VAS、WOMAC评分均逐步降低,Lysholm评分逐步升高(P0.05);研究组治疗后1个月、治疗后3个月VAS、WOMAC评分低于对照组,Lysholm评分高于对照组(P0.05)。两组治疗后3个月SF-36各维度评分均较治疗前升高,且研究组高于对照组(P0.05)。两组不良反应发生率对比未见统计学差异(P0.05)。结论:关节镜联合富血小板血浆治疗膝关节半月板损伤患者,可促进膝关节功能的恢复,可有效缓解手术治疗后的疼痛症状,改善患者生活质量,具有较好的临床应用价值。