Influence of sodium diethyldithiocarbamate (Imuthiol) on lymphocyte function and growth in weanling pigs

Mitogen-stimulated lymphocyte proliferation, delayed-type hypersensitivity (DTH) reactions, interleukin-2 (IL-2) production, and growth performance were evaluated in 3-week-old pigs treated with imuthiol. Lymphocyte proliferative responses to Con A and PWM were reduced (P < 0.05) in pigs treated with imuthiol at 25 mg/kg; PHA proliferative responses were not influenced by imuthiol treatment. Imuthiol at 2.5 mg/kg and 25 mg/kg lowered IL-2 production when compared to saline-treated controls. Delayed-type hypersensitivity responses to PHA were higher in 25 mg/kg imuthiol-treated pigs; however, 2.5 mg/kg imuthiol-treated pigs had lower DHT reactions. Imuthiol at 2.5 mg/kg and 25 mg/kg reduced (P < 0.05) average daily feed intake. These data suggest that in vivo imuthiol treatment in pigs lowers lymphocyte proliferative responses, IL-2 production, and growth performance.     

白头翁提取方法比较

本试验采用热回流和超声两种不同提取方法,以水及不同浓度的乙醇溶液为溶剂,制备10个样品,采用高效薄层色谱法、高效液相色谱法,通过比较得膏率、色谱图、白头翁皂苷B4峰面积等,考察提取方法对白头翁活性成分的影响。结果表明,两种提取方法中,热回流提取得膏率、白头翁皂苷B4得率均较超声提取法高;乙醇浓度对皂苷B4的提取有一定影响,热回流提取70%～80%乙醇提取率最高,超声提取50%～70%乙醇提取率最高。研究结果为白头翁提取方法的选用提供了科学数据。     

Stable carbon isotopes accurately predict diet selection by sheep fed mixtures of C3 annual pastures and saltbush or C4 perennial grasses

The stable carbon isotope technique has been widely used to infer the dietary ecology of a range of animal species; however calibration of the technique with animals fed known diets is essential for accurate back-calculation of dietary preferences. The aim of this study was to identify suitable samples and back-calculation methods to predict short-term (2 to 3 week) dietary selection by sheep among plants with C₃ and C₄ photosynthetic pathways. Variation in integration time of dietary carbon into plasma and faeces; diet-tissue discrimination of carbon isotopes (fractionation) and the importance of accounting for the digestible or indigestible components of the diet was investigated. The results indicate that faecal and rumen samples provided the most accurate prediction of short term dietary changes in sheep selecting between C₃ and C₄ plants. The most accurate back-calculation method for these samples used δ¹³C of the C₃ and C₄ plants and accounted for both diet-tissue discrimination and differences in the indigestibility between the C₃ and C₄ forage. For faecal samples, the organic matter content of the diet originating from C₄ plants could be predicted with a mean error as low as 2.7%. Wool and plasma samples were not conducive to predicting proportion of C4 forage in the diet within 18 days after a change in diet; however plasma could be used to discriminate between animals fed 100% C₃ and C₄ diets after 3 days. The δ¹³C technique provides a valuable tool for researchers when designing pastures for dual environmental and production purposes. An understanding of what sheep select allows for development of appropriate grazing management strategies to optimise productivity and/or persistence of target species.     

Bovine herpesvirus 4-associated postpartum metritis in a Spanish dairy herd

In more than 10 Spanish dairy cows, a bovine herpesvirus 4 (BHV4) associated postpartum metritis was confirmed by virus isolation, BHV4-glycoprotein B (gB) PCR and/or serology. In this study, 12 cows with, and, at the time of sampling, 3 cows without clinical signs of acute postpartum metritis from one large dairy herd in Spain were examined for bacterial and viral infections. Blood, placenta/caruncles and uterine contents were collected between day 1 and day 20 post-calving, and examined for the presence of bacteria and for viruses by virus isolation, BHV4 DNA by BHV4-gB PCR and/or BHV4 antibody titres. Bovine herpesvirus 4 was detected in 83% of the cases with clinical signs of acute postpartum metritis by virus isolation and/or BHV4-gB PCR. An increase of BHV4 antibodies was detected in all examined postpartum metritis cows and in the 3 cows without clinical metritis. Two of these 3 cows developed severe metritis a few dayss after collecting the first blood sample. A concurrent infections of BHV4 and bacteria, mainly Arcanobacterium pyogenes and Streptococcus sp., were detected in 73% of the examined uterine contents collected from postpartum metritis affected cows. This case-report study showed a clear association between BHV4 infections and acute postpartum metritis in dairy cows. In addition, the BHV4-associated postpartum metritis appeared to be an emerging syndrome in this Spanish herd.     

Regulation of uterine function by cytokines in cows: Possible actions of tumor necrosis factor-α, interleukin-1α and interferon-τ

When animals do not become pregnant, regression of the corpus luteum (CL) is essential for normal cyclicity because it allows the development of a new ovulatory follicle. Luteal regression is caused by a pulsatile release of prostaglandin (PG) F_2α from the uterus in the late luteal phase in most mammals including cattle. Although it has been proposed in ruminants that pulsatile PGF_2α secretion is generated by a positive feedback loop between luteal and/or hypophyseal oxytocin and uterine PGF_2α, the bovine endometrium may possess other mechanisms for initiation of luteolytic PGF_2α secretion. There is increasing evidence that several cytokines mainly produced by immune cells modulate CL and uterine function in many species. Tumor necrosis factor‐α (TNF‐α) stimulates PGF_2α output from bovine endometrium not only at the follicular phase but also at the late luteal phase. Administration of TNF‐α at a high concentration prolongs luteal lifespan, whereas administration of a low concentration of TNF‐α accelerates luteal regression in cows. The data obtained from the authors’ previous in vitro and in vivo studies strongly suggest that TNF‐α is a crucial factor in regulating luteolysis in cows. The authors’ recent study has shown that interleukin‐1α mediates PG secretion from bovine endometrium as a local regulator. Furthermore, interferon‐τ (IFN‐τ) suppresses the action of TNF‐α on PGF_2α synthesis by the bovine endometrium in vitro, suggesting that IFN‐τ plays a luteoprotective role by inhibiting TNF‐α‐induced PGF_2α production in early pregnancy. The purpose of the present review is to summarize current understanding of the endocrine mechanisms that regulate uterine function by cytokines during the estrous cycle and early pregnancy in cows.     

归参汤对免疫抑制小鼠血清中IL-2、TNF-α和脾细胞Th1/Th2细胞因子的影响

为了探讨归参汤(GST)对免疫抑制小鼠血清中IL-2、TNF-α和脾细胞Th1/Th2细胞因子的影响。本试验采用环磷酰胺制造免疫抑制模型,利用双抗夹心ELISA法,观察归参汤对小鼠血清中IL-2、TNF-α的影响;RT-PCR法观察归参汤对小鼠脾细胞中INF-γ、IL-4、T-bet和GATA-3的mRNA表达的影响。结果显示:归参汤高剂量组可以显著增加免疫抑制小鼠血清中IL-2、TNF-α的含量(P<0.01),提高INF-γ的表达(P<0.05),降低IL-4的含量(P<0.05),升高T-bet(P<0.05),降低GATA-3的表达(P<0.05)。归参汤的免疫增强作用与升高血清中IL-2、TNF-α有关,且升高INF-γ/IL-4纠正免疫抑制小鼠Thl/Th2细胞因子的比例紊乱,其机制可能部分归因于对T-bet和GATA-3的mRNA表达的影响。     

高致病性猪繁殖与呼吸综合征病毒非结构蛋白Nsp4的表达及其抗血清的制备

根据GenBank中已发表的高致病性猪繁殖与呼吸综合征病毒（Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus,PRRSV）HuN4株全基因组序列,设计合成一对引物,对PRRSV HuN4株非结构蛋白Nsp4（Nonstructural protein 4基因进行RT-PCR扩增,克隆到原核表达载体pET30a（＋）中,构建重组表达载体pET30a-Nsp4,经酶切测序鉴定。将pET30a-Nsp4转化表达菌株BL21（DE3）,诱导可表达分子量约为27kDa重组蛋白。Westernblot显示其具有较好的反应原性,经镍离子亲和层析（Ni-NTA）纯化获得了高纯度的可溶性重组蛋白。将纯化的Nsp4蛋白免疫BALB／c小鼠,抗血清ELISA效价达1：16000,Western blot和IFA表明,所制备的抗血清能够特异性识别PRRSV自身表达的Nsp4蛋白。本研究获得了可溶性的PRRSV Nsp4蛋白,制备了Nsp4特异性多抗血清,为进一步研究Nsp4蛋白的亚细胞定位及功能奠定了基础。     

The optimal immunization procedure of DNA vaccine pcDNA–TA4–IL-2 of Eimeria tenella and its cross-immunity to Eimeria necatrix and Eimeria acervulina

The immunization procedure of DNA vaccine pcDNA–TA4–IL-2 of Eimeria tenella, including route, dose, time of immunization and age of primary immunization of chicken, was optimized. The stability and the cross-species protection of the vaccine were also analyzed. Efficacy of immunization was evaluated on the basis of oocyst decrease ratio, lesion score, body-weight gain and the anti-coccidial index (ACI). Chinese Yellow chickens were randomly distributed into corresponding groups (30/group). The challenged, unchallenged and vector control groups were designed. The results illustrated that 25 μg was the optimal dose and intramuscular injection was the most effective route to induce protective immunity. There were no significant differences of ACIs between boosting and non-boosting groups. Storage time and temperature had little effect on the immunizing efficacy of the vaccine. The vaccine could provide partial cross-protection against the challenge with E. necatrix and E. acervulina, but not with E. maxima.     

Differential Expression Analysis of MUC4 and MUC13 Genes Between Resistant and Sensitive Weaned Meishan Piglets to ETEC F18

MUC4 and MUC13 genes as important candidate genes for enterotoxigenic Escherichia coil (ETEC) F4 resistance,may play an important role in the process of against ETEC F18 infection in weaned piglets. In this study,ETEC F18-resistant and -sensitive weaned Meishan piglets were used,and the expression levels of MUC4 and MUC13 genes in 11 tissues (heart,liver,spleen,lung,kidney,stomach,muscle,thymus,lymph nodes,duodenum and jejunum) were determined by quantitative Real-time PCR. The results showed that MUC4 and MUC13 genes were broadly expressed with different expression levels in all the 11 tissues. In the thymus and lymph tissues,the expression of MUC4 gene in resistant piglets was significantly higher than that in sensitive piglets (P<0.05);In the lung tissue,theMUC13 gene expression level in resistant individuals was significantly higher than that in sensitive individuals (P<0.05),and in the intestinal tissues of duodenum and jejunum, the expression level of MUC13 gene was relatively higher in resistant individuals. Thus we speculated that the high expression of MUC4 gene in immune tissues and MUC13 gene in intestinal tissues might improve the immune ability of piglets,protect and lubricate the intestinal tract, and resist ETEC F18 infection.