Selection and identification of a precocious line of Eimeria intestinalis with enlarged oocysts and deletion of one generation of schizogony

Parasitology Research - Rabbit coccidiosis is a common parasitic disease and responsible for enormous economic losses in the rabbit industry. Eimeria intestinalis, one of the highly pathogenic and...     

Acute fasting decreases the expression of GLUT1 and glucose utilisation involved in mouse oocyte maturation and cumulus cell expansion

Acute fasting impairs meiotic resumption and glucose consumption in mouse cumulus cell and oocyte complexes (COCs). This study examines the effects of acute fasting on the regulation of glucose transporter 1 (GLUT1) expression and glucose consumption in oocyte maturation. Our results indicate that the restriction of glucose utilisation by 2-deoxyglucose (2-DG) mimicked the inhibitory effects of acute fasting on oocyte meiotic resumption and cumulus cell expansion, effects that were rescued by high glucose concentrations in the culture medium. GLUT1 protein levels were higher in cumulus cells compared with oocytes, and GLUT1 expression in COCs increased with FSH treatment in vitro. However, under acute fasting conditions, GLUT1 expression in COCs decreased and the response to FSH disappeared. Exposure to high glucose conditions (27.5mM and 55mM), significantly increased both glucose consumption and GLUT1 levels in COCs. Inhibition of GLUT1 function using an anti-GLUT1 antibody significantly inhibited FSH-induced oocyte meiotic resumption. Taken together, these results suggest that acute fasting decreases GLUT1 expression and glucose utilisation, inhibiting the processes of oocyte maturation and cumulus cell expansion.     

中国13个省份结核分枝杆菌5种特异性抗原人T细胞表位多态性分析

目的 分析我国结核分枝杆菌复合群(MTBC)临床分离株中GlnA1、Mpt70、LppX、GroES和LpqH 5种抗原编码基因多态性及其人T细胞表位的多态性。方法 选取13个省份临床分离的173株MTBC,采用PCR扩增5种抗原基因,并运用BioEdit软件进行序列比对,分析其人T细胞表位与非表位的变异情况。利用Mega 6.0软件分别计算同义突变率(dS)和非同义突变率(dN)及其比值。结果 173株菌的基因glnA1非表位区出现2个非同义突变位点;基因mpt70表位区出现1个非同义突变位点;基因lpqH表位区表现为1个非同义突变位点和1个同义突变位点;groES在整个基因中未发现任何突变;基因lppX表位区表现为5个非同义突变和1个同义突变位点,其中152位的氨基酸相同位点有9株菌发生了同义突变,表现较高的多态性。同时基因lppX的15个T细胞抗原表位中有7个表位发生了改变,其dN/dS值为0.19。结论 结核分枝杆菌抗原Mpt70、LppX和LpqH的人T细胞表位区具有多态性,反映了此抗原可能参与逃避宿主免疫的分化选择。GlnA1的非表位区的多态性,对该菌株的免疫反应影响较小。GroES序列相对保守,不具有明显的多态性,可能对结核分枝杆菌的鉴定、诊断及新型疫苗的研制具有重要作用。     

Effects of different promoters on the protective efficacy of recombinant Marek’s disease virus type 1 expressing the VP2 gene of infectious bursal disease virus

The vaccine efficacy of recombinant viruses can be influenced by many factors. Accordingly, the activity of promoters has been one of the major factors affecting the antigen expression and protection rate. In the present study, two recombinant Marek’s disease virus type 1 (MDV1) vaccines containing the VP2 gene of infectious bursal disease virus (IBDV) under control of different promoters were generated from overlapping fosmid DNAs. The rMDV-Pec-VP2 virus containing the VP2 gene under control of the Pec promoter (CMV enhancer and chicken β-actin chimera promoter) demonstrated higher VP2 expression and stronger antibody response against IBDV in chickens than the rMDV-CMV-VP2 virus using the CMV promoter. After IBDV lethal challenge in specific-pathogen-free chickens, rMDV-Pec-VP2 provided complete protection against developing mortality, clinical signs, and the formation of bursal lesions, which was better than that provided by rMDV-CMV-VP2. Our findings indicate that the protective efficacy of the recombinant MDV1 vaccine against IBDV highly correlates with VP2 expression. This recombinant MDV1 vaccine expressing VP2 could have significant potential as a bivalent vaccine against both virulent IBDV and MDV infections in chickens.     

Strategy to enhance the therapeutic effect of doxorubicin in human hepatocellular carcinoma by selenocystine,a synergistic agent that regulates the ROS-mediated signaling

Doxorubicin-based chemotherapy represents one of the most effective ways in combating human cancers. However, its clinical use is limited by severe side effects. Selenocystine (SeC) is a natural available selenoamino acid with novel anticancer efficacy. In this study, we used SeC to sensitize HepG2 human hepatocellular carcinoma (HCC) cells to DOX, and to achieve anticancer synergism in vitro and in vivo. Treatment with DOX dose-dependently reduced HepG2 cell viability through initiating cell apoptosis and strong G2/M phase cell cycle arrest. Mechanistic studies indicated that this sensitization of SeC to DOX was achieved by triggering inactivation of ERK and AKT and DNA damage through reactive oxygen species (ROS) overproduction. Pretreatment with inhibitors of ERK and AKT markedly enhanced combined treatment-induced cell killing, indicating that combined treatment-induced HCC cell killing with ERK- and AKT-dependent manner. Furthermore, inhibition of ROS effectively attenuated combined treatment-induced DNA damage and inactivation of ERK and AKT. Additionally, xenograft hepatocellular carcinoma growth was also effectively inhibited by combined treatment through induction of cell apoptosis in vivo. Taken together, our results suggest that the strategy to use SeC and DOX in combination could be a highly efficient way to achieve anticancer synergism against HCC.     

Porcine circovirus type 2 and its associated diseases in China

Porcine circovirus type 2 (PCV2) has been recognized as an important vial pathogen for global swine industry. The virus is associated with postweaning multisystemic wasting syndrome (PMWS) and other syndrome diseases collectively known as porcine circovirus-associated disease (PCVAD). PCV2 infection and PMWS have caused great impact on the pig production in China during the past 10 years. This review will involve in the history of PCVAD, serological epidemiology of PCV2 infection, and clinical aspect of PCVAD, and the genomic characteristics, variation and genotyping of PCV2, as well as control situation of PCVAD in China.