2014年-2016年广西地区猪繁殖与呼吸综合征病毒Nsp2和ORF5基因的遗传多样性分析

为了解广西地区猪繁殖与呼吸综合征病毒(PRRSV)流行毒株的遗传进化情况,对2014年-2016年来自广西各地的部分PRRSV阳性病料进行Nsp2和ORF5基因的扩增和测序分析.结果获得34个Nsp2基因序列和45个ORF5基因序列,均属于美洲型毒株.Nsp2基因间核苷酸序列的同源性为91.8％~100％,与PRRSV美洲型毒株VR-2332、CH-1a、JXA1及NADC30株核苷酸序列的同源性分别为81.3％~84.3％、88.9％~92.1％、94.3％~99.3％和73.5％~75.1％,而与PRRSV欧洲型毒株LV株核苷酸序列的同源性为51.5％~53.2％.ORF5基因间核苷酸序列的同源性为82.8％~100％,与PRRSV美洲型毒株VR-2332、CH-1a、JXA1及NADC30株核苷酸序列的同源性分别为83.7％~99.5％、85％~95％、83.8％~99.7％和83.2％~86.4％,而与PRRSV欧洲型毒株LV株核苷酸序列的同源性为62.4％~64.5％.基于Nsp2和ORF5基因推导的氨基酸序列绘制的遗传进化树中,广西地区的毒株主要分布在以JXA1为代表的Ⅳ亚群.表明当前广西PRRSV流行毒株以JXA1株为代表的高致病性美洲型毒株为主,各毒株Nsp2和ORF5基因序列存在一定的差异,尚未发现欧洲型毒株和美洲型NADC30类毒株.     

Effect of miR-181b on cell proliferation and expression of Bcl-2 and SP1 in HepG2 cells

AIM: To investigate the role of miR-181b in the expression of Bcl-2 and SP1 at mRNA and protein levels in the human hepatoma G2 cells (HepG2), and to explore the effect of miR-181b on the regulation of HepG2 cell proliferation. METHODS: The synthetic double-strand complementary DNA based on the sequence of miR-181b was inserted into the vector of miRNASelect^TM pEGP-miR. The microRNA high-expression plasmid was cloned, and the sequences were identified. The miR-181b plasmid was transfected into HepG2 cells with liposomes. The stable cell line was screened by puromycin. The mRNA and protein levels of Bcl-2 and SP1 were measured by RT-PCR and Western blotting, respectively. Methyl thiazolyl tetrazolium (MTT) method was used to analyze the proliferation of HepG2 cells. RESULTS: The Western blotting results showed that miR-181b inhibited the protein expression of Bcl-2 and SP1. The result of RT-PCR also indicated that the mRNA expression of Bcl-2 and SP1 was suppressed. Compared with the control, the growth rate of HepG2 with high expression of miR-181b was significantly decreased.CONCLUSION: miR-181b inhibits the proliferation of HepG2, which may be related to the down-regulation of Bcl-2 and SP1.     

Greenhouse gas emissions in response to straw incorporation,water management and their interaction in a paddy field in subtropical central China

A field experiment was conducted to study the effects of combination of straw incorporation and water management on fluxes of CH₄, N₂O and soil heterotrophic respiration (Rh) in a paddy field in subtropical central China by using a static opaque chamber/gas chromatography method. Four treatments were set up: two rice straw incorporation rates at 0 (S1) and 6 (S2) t ha^?1 combined with two water managements of intermittent irrigation (W1, with mid-season drainage) and continuous flooding (W2, without mid-season drainage). The cumulative seasonal CH₄ emissions for the treatments of S1W2, S2W1 and S2W2 increased significantly by 1.84, 5.47 and 6.63 times, respectively, while seasonal N₂O emissions decreased by 0.67, 0.29 and 1.21 times, respectively, as compared to S1W1 treatment. The significant increase in the cumulative Rh for the treatments S1W1, S2W1 and S2W2 were 0.54, 1.35 and 0.52 times, respectively, in comparison with S1W2. On a seasonal basis, both the CO₂-equivalents (CO₂e) and yield-scaled CO₂e (GHGI) of CH₄ and N₂O emissions increased with straw incorporation and continuous flooding, following the order: S2W2>S2W1>S1W2>S1W1. Thus, the practices of in season straw incorporation should be discouraged, while mid-season drainage is recommended in paddy rice production from a point view of reducing greenhouse gas emissions.     

牦牛源正呼肠孤病毒2型的检测和分离鉴定

旨在调查川西北牦牛哺乳动物正呼肠孤病毒(MRV)的感染情况并分离病毒.采用RT PCR方法,对采自川西北15个牧场的72份牦牛腹泻粪便样本和其中5个牧场的15份腹泻牦牛血清样本进行MRV检测,阳性样本进一步用分型PCR确定其血清型.结果 显示,粪便样本中MRV检出率为20.83％(15/72),血清2型的比例为60％(...     

紫锥菊对传染性法氏囊疫苗免疫效果的影响

为了探讨紫锥菊作为免疫增强剂的免疫效果和机理,本试验用1日龄的罗斯308肉鸡作为试验材料并用传染性法氏囊疫苗进行免疫。紫锥菊提取物分3种剂量组(A组0.1 mL/只、B组0.5 mL/只、C组1 mL/只)在6日龄开始连续给雏鸡口服7 d,在13,20,27,34,41日龄采血检测外周血中法氏囊病毒抗体,同时测定外周血中IL-2和TNF-α的含量,计算肉鸡的生产性能。结果表明,紫锥菊提取物能明显提高鸡外周血中法氏囊病毒抗体滴度,以及细胞因子IL-2和TNF-α含量,并能改善肉鸡的生产性能。所用3个剂量组中,以B组的0.5 mL/只为最佳的用药剂量。说明紫锥菊提取物具有明显的免疫促进作用。     

Pain management in horses and farm animals

Objective: This review discusses the different analgesic drugs and routes of administration used in large animals for acute pain management. General guidelines and doses are given to assist in choosing techniques that provide effective analgesia. Etiology: Noxious stimuli are perceived, recognized, and localized by specialized sensory systems located at spinal and supraspinal levels. Diagnosis: Localizing the source of the noxious stimulus as well as understanding the behavioral aspects and physiological changes that result from such insult is important to adequately diagnose and treat pain. Pain assessment is far from being definite and objective; not only are there species differences, but also individual variation. In addition, the behavioral and physiological manifestations vary with the acute or chronic nature of pain. Therapy: Pain management should include (1) selecting drugs that better control the type of pain elicited by the insult; (2) selecting techniques of analgesic drug administration that act on pathways or anatomical locations where the nociceptive information is being processed or originating from; (3) combining analgesic drugs that act on different pain pathways; and (4) provide the best possible comfort for the animal. Prognosis: Providing pain relief improves the animal's well being and outcome; however, interpreting and diagnosing pain remains difficult. Continuing research in pain management will contribute to the evaluation of the pathophysiology of pain, pain assessment, and newer analgesic drugs and techniques.     

陕西黄土高原中南部土壤CO2释放量变化研究

本文根据 NaOH溶液吸收CO_2的方法 ,对陕西黄土高原中南部4个观测点的土壤CO_2释放量时行了昼夜观测。观测结果表明 ,不同地区、不同气候和不同土质土壤CO_2释放量存在差异 ,冷干地区较暖湿地区土壤CO_2释放量少,凉季较暖季土壤CO_2释放量少;粘性硬质土较松散黄土CO_2 释放量少。长武、洛川、西安南郊土壤CO_2释放量变化再次证明 ,在厚层黄土发育的地区 ,土壤CO_2释放量变化相对于大气温度变化具有滞后性,从当日早晨至次日早晨,CO_2释放量具有由低变高再变低的普遍规律。     

硅对盐胁迫下黄瓜幼苗根系质膜、液泡膜酶活性的影响

研究硅对盐胁迫下黄瓜幼苗生长及根细胞质膜H^＋-ATPase、液泡膜H^＋-ATPase、H^＋-PPase和Ca^2＋-ATPase活性的影响。结果表明：盐胁迫严重抑制黄瓜幼苗生长,根细胞质膜H^＋-ATPase、液泡膜H^＋-ATPase、H^＋-PPase和Ca^2＋-ATPase活性明显降低。硅处理明显提高盐胁迫黄瓜根液泡膜H^＋-ATPase、H^＋-PPase、Ca^2＋-ATPase活性,一定程度上维持了液泡膜质子泵活性,有效地防御了细胞质酸化,这可能是硅提高黄瓜耐盐性的一个重要因素。     

Effect of tetrandrine on radiosensitivity of nasopharyngeal carcinoma cells

AIM: To investigate the mechanism of the radiosensitizing effect of maximum non-cytotoxic doses of tetrandrine (Tet) on nasopharyngeal carcinoma cell lines CNE1 and CNE2.METHODS: The cells were treated with ma-ximum non-cytotoxic doses of Tet (for CNE1 cells at 1.5 μmol/L and for CNE2 cells at 1.8 μmol/L), irradiation at 4 Gy, or combination of irradiation and maximum non-cytotoxic doses of Tet. The cell cycle distribution was analyzed by flow cytometry. The protein levels of γ-H2AX, cleaved caspase-3, p-CDC25C, CDK1, p-CDK1, cyclin B1, ERK and p-ERK were determined by Western blot.RESULTS: The expression of γ-H2AX was increased in CNE1 cells and CNE2 cells after combined treatment with irradiation and maximum non-cytotoxic doses of Tet. The percentages of CNE1 cells and CNE2 cells at G₂/M phase in irradiation group were (18.09±0.42)% and (18.48±1.32)%, respectively, which were decreased to (15.88±1.04)% and (13.80±0.82)% in combined treatment group, respectively (P<0.05). Combined treatment enhanced the increase in the protein level of cleaved caspase-3 caused by irradiation. The protein levels of p-CDC25C and p-CDK1 were increased in a dose-dependent manner by Tet treatment (P<0.05), while the expression of CDK1 showed no difference among different doses of Tet treatments. The protein levels of p-CDC25C, p-CDK1 and CDK1 showed no difference after the treatment with maximum non-cytotoxic doses of Tet. The combined treatment with irradiation and the maximum non-cytotoxic doses of Tet decreased the protein levels of p-CDC25C and p-CDK1 (P<0.05), increased the expression of cyclin B1, and had no influence on the expression of CDK1 (P<0.05). The combined treatment resulted in an increase in the protein level of p-ERK1 (P<0.05).CONCLUSION: The maximum non-cytotoxic doses of Tet enhance the DNA damage and apoptosis in CNE1 cells and CNE2 cells caused by irradiation, and the mechanism might be associated with ending of G₂/M arrest via activation of ERK/CDC25C/CDK1/cyclin B1 pathways.     

First report of porcine circovirus type 2 infections in Cuba

To obtain information about the porcine circovirus type 2 (PCV2) infection status of pigs in Cuba and the probable association of PCV2 with other porcine viruses, tissue samples collected from ill pigs were evaluated using polymerase chain reaction (PCR). The PCR analysis showed that 67.7% of the samples (23/34) from seven swine herds of six different geographic regions were detected to be positive for PCV2. Ten of the 23 PCV2 positive samples (43.5%) shown a concurrent infection with porcine parvovirus (PPV) and 17 of 23 PCV2 positive samples (73.9%) exhibited a concomitant infection with classical swine fever virus (CSFV). This study is the first report of PCV2 infecting pigs with different clinical conditions in Cuban swine herds and provides evidence of PCV2 co-infection with PPV and CSFV in the field.