卷烟烟气及绿茶对蚕豆根尖细胞微核的诱导作用

[目的]研究不同类型卷烟烟气水溶物对蚕豆（ViciafabaL.）根尖细胞微核的诱变作用,并在此基础上探讨了绿茶添加剂对卷烟烟气诱导微核的抑制作用。[方法]卷烟品牌分别为白沙、中南海和狮牌,类型分别为烤烟型、混合型和雪茄型。烟气水溶物的浓度分别为1/8母液、1/4母液和1/2母液,烟气茶溶物浓度为1/4母液。[结果]烟气水溶物能够引起蚕豆根尖细胞微核率发生明显变化,并在一定范围内随浓度增强而加强,其中,狮牌〉白沙〉中南海。相同浓度下,各类型卷烟烟气茶溶物引起的细胞微核率低于同种卷烟烟气水溶物。绿茶对狮牌卷烟微核诱导的抑制作用最明显,对白沙次之,对中南海卷烟最弱。[结论]该研究可为将绿茶用作添加物从而降低烟毒的可行性提供科学依据。     

醋酸铅对小鼠卵巢颗粒细胞凋亡基因p53、Bax、Bcl-2表达的影响

将40只未成年雌性昆明系小鼠随机分成3个处理组和1个对照组,每组10只。处理组小鼠分别连续2 d腹腔注射铅10、20、40 mg/kg（按体质量给药）,对照组小鼠注射等体积的生理盐水。于注射后24、72 h分离卵巢,用原位末端标记法（TUNEL）测定卵巢颗粒细胞的凋亡率,同时用半定量RT-PCR方法检测凋亡基因p53、Bax、Bcl-2mRNA表达。结果表明,铅可促进颗粒细胞凋亡,且随剂量的增加和作用时间的延长,颗粒细胞中p53、Bax基因表达量逐渐增加,与对照组相比差异显著或极显著（P〈0.05或P〈0.01）;而Bcl-2基因表达量则逐渐减少（P〈0.05或P〈0.01）;表明铅可通过上调促细胞凋亡基因p53、Bax基因表达量,下调Bcl-2基因表达量,诱导卵巢颗粒细胞的凋亡。     

利用柞蚕核型多角体病毒表达载体系统在柞蚕蛹中表达增强型绿色荧光蛋白

为了探讨外源蛋白在柞蚕蛹-柞蚕核型多角体病毒(ApNPV)表达系统的表达水平和稳定性,将增强型绿色荧光蛋白(EGFP)基因克隆到柞蚕核型多角体病毒转移表达载体pApM748BE中,获得重组质粒DNA,与ApNPV DNA共转染樗蚕(Phi-losamia cynthiam)培养细胞Pc-01后,用末端稀释法筛选获得重组病毒ApNPV-Δph/egfp+。将该重组病毒感染柞蚕蛹,采用SDS-PAGE和Western blot方法检测EGFP在柞蚕蛹中的表达,结果显示:在柞蚕蛹感染重组病毒ApNPV-Δph/egfp+后6 d,EG-FP就有明显的表达;感染后12～18 d,蛹体液中的EGFP含量保持较高水平,以EGFP标准样品定量分析EGFP在柞蚕蛹体液中的表达水平高于1 mg/mL;感染后30～39 d仍可以检测到蛹体液中EGFP的表达,而且蛋白稳定。研究结果表明,利用柞蚕核型多角体病毒作表达载体,可在柞蚕蛹中高效稳定地表达EGFP,并且EGFP在雌雄蛹间的表达水平无明显差异。     

Evaluation of a recombinant measles virus expressing hepatitis C virus envelope proteins by infection of human PBL-NOD/Scid/Jak3null mouse

In this study, we infected NOD/Scid/Jak3null mice engrafted human peripheral blood leukocytes (hu-PBL-NOJ) with measles virus Edmonston B strain (MV-Edm) expressing hepatitis C virus (HCV) envelope proteins (rMV-E1E2) to evaluate the immunogenicity as a vaccine candidate. Although human leukocytes could be isolated from the spleen of mock-infected mice during the 2-weeks experiment, the proportion of engrafted human leukocytes in mice infected with MV (10³–10⁵ pfu) or rMV-E1E2 (10⁴ pfu) was decreased. Viral infection of the splenocytes was confirmed by the development of cytopathic effects (CPEs) in co-cultures of splenocytes and B95a cells and verified using RT-PCR. Finally, human antibodies against MV were more frequently observed than E2-specific antibodies in serum from mice infected with a low dose of virus (MV, 10⁰–10¹ pfu, and rMV-E1E2, 10¹–10² pfu). These results showed the possibility of hu-PBL-NOJ mice for the evaluation of the immunogenicity of viral proteins.     

Herpesvirus systematics

This paper is about the taxonomy and genomics of herpesviruses. Each theme is presented as a digest of current information flanked by commentaries on past activities and future directions.     

Effect of Estradiol-17β on protein synthesis and degradation rates in fused bovine satellite cell cultures

Although androgenic and estrogenic steroids are widely used to enhance muscle growth and increase feed efficiency in feedlot cattle, their mechanism of action is not well understood. Further, in vivo studies indicate that estradiol (E2) affects muscle protein synthesis and/or degradation, but in vitro results are inconsistent. We have examined the effects of E2 treatment on protein synthesis and degradation rates in fused bovine satellite cell (BSC) cultures. Additionally, to learn more about the mechanisms involved in E2-enhanced muscle growth, we have examined the effects of compounds that interfere with binding of E2 or insulin-like growth factor (IGF)-1 to their respective receptors on E2-induced alterations in protein synthesis and degradation rates in BSC cultures. Treatment of fused BSC cultures with E2 results in a concentration-dependent increase (P < 0.05) in protein synthesis rate and a decrease (P < 0.05) in protein degradation rate. The pure estrogen antagonist ICI 182 780 suppresses (P < 0.05) E2-induced alterations in protein synthesis and degradation in fused BSC cultures. The G-protein coupled receptor (GPR)-30 agonist G1 does not affect either synthesis or degradation rate, which establishes that GPR30 does not play a role in E2-induced alterations in protein synthesis or degradation. JB1, a competitive inhibitor of IGF-1 binding to the Type 1 insulin-like growth factor receptor (IGFR-1), suppresses (P < 0.05) E2-induced alterations in protein synthesis and degradation. In summary, our data show that E2 treatment directly alters both protein synthesis and degradation rates in fused BSC cultures via mechanisms involving both the classical estrogen receptor (ER) and IGFR-1.     

鸡X期胚盘细胞电转染外源基因条件的探索

以EGFP为报告基因体外电穿孔转染鸡X期胚盘细胞,探讨适宜电转染条件以及影响鸡ES细胞存活率和转染率因素。分离鸡X期胚盘细胞进行培养、传代及鉴定,二代细胞设定不同的电压、脉冲时间、质粒浓度、细胞密度及孵育温度等条件转染。电击后10 min,0.4%台盼蓝染色,血细胞计数板计数,计算存活率。48 h后在荧光显微镜下计绿色荧光细胞数和总细胞数,计算转染率。结果表明:电转染鸡ES细胞的最优化电压为280 v,脉冲时间为75μs,质粒浓度为20μg/mL,转染前4℃、转染后25℃(室温)或4℃各静置10 min,细胞密度调整在1×105个/mL×106个/mL,尽量使细胞处于对数生长期。电穿孔法转染鸡ES细胞是简便有效的方法,利用优化条件转染ES细胞,可以满足进一步实验的要求。     

Case Study of Abortion in a Mare: Coelosomy with urachal dilatation following umbilical cord torsion

Tractor, a 14-year-old Argentinean polo pony mare, aborted at the end of the 2nd trimester of gestation. Incision of the placenta revealed obvious dilatation of the urachus. The umbilical cord was twisted at several locations. There was a deficit in the abdominal wall and the fetal viscera were in contact with the dilatation. The fetus presented complete scoliosis at 90°. Torsion of the umbilical cord, through more than one turn, was evident around the fetlock of the left forelimb.