Intramammary infusion of an Enterococcus faecium SF68 preparation promoted the involution of drying off Holstein cows partly related to neutrophil‐associated matrix metalloproteinase 9

A problem for dairy cows following milk stasis is to cope with a high risk of intramammary infection and there is a need to initiate an extensive renewal of secretory modules in mammary glands so that milk production in next lactation may be optimized. We recently reported that ultrasonicated Enterococcus faecium SF68 (SF68) is compatible with cow mammary glands and an enhancer of innate immunity during the immediate post‐milk stasis period. The current study further examines the concomitant effect of ultrasonicated SF68 on mammary tissue remodeling. Four Holstein cows each received intramammary infusions of regular antibiotic dry‐cow formula (positive control) and two different doses of SF68 in different quarters. Analyses of individual quarter secretion samples showed faster neutrophil infiltration, earlier modifications in protein composition, including caseins and lactoferrins, as well as more prompt elevation of the specific unit of 92‐kDa matrix metalloproteinase 9 (MMP9) in SF68‐infused quarters compared to the positive controls. Intramammary infusion of ultrasonicated SF68 seems able to accelerate the regression of mammary synthetic capacity and potentiate the breakdown of glandular extracellular matrix, indicating a more efficient mammary gland involution. Correlation analyses imply that the ability of ultrasonicated SF68 to induce faster neutrophil chemotaxis and the associated MMP9 release is partly responsible.     

六氟化硫（SF6）示踪法测定反刍动物甲烷排放的技术

详细描述了用六氟化硫示踪法测定反刍动物甲烷排放的技术，包括基本原理、仪器准备和测试条件。还研究了适用于中国的采气设备、示踪参数、测定条件等技术，本技术经济实用且易操作，现正在试用。     

对杭州地区4种猪病的血清学调查分析

通过对于杭州地区规模化猪场PRRS、PCV2、PR、SF等4种疾病抗体的血清学检测,发现PRRS、PCV2、PR感染率依次降低,PR的野毒感染率31.2%,总抗体阳性率为68%,猪瘟的免疫保护率为74%;下半年与上半年相比,PRRS稍有升高,SF免疫合格率有所下降,PR免疫转阳率下降,感染率稍有升高,表明防疫形势不容乐观.PRRS已经有大部分场次(93%)发生,75%的场次存在PCV2感染,7%的场次感染PR,6.4%的场次猪瘟免疫抗体不合格.建议继续做好PR、SF的免疫预防,完善PRRS疫苗,加强PCV2疫苗的研制.     

Radiosensitivity and capacity for radiation-induced sublethal damage repair of canine transitional cell carcinoma (TCC) cell lines

Understanding the inherent radiosensitivity and repair capacity of canine transitional cell carcinoma (TCC) can aid in optimizing radiation protocols to treat this disease. The objective of this study was to evaluate the parameters surviving fraction at 2 Gy (SF(2) ), α/β ratio and capacity for sublethal damage repair (SLDR) in response to radiation. Dose-response and split-dose studies were performed using the clonogenic assay. The mean SF(2) for three established TCC cell lines was high at 0.61. All the three cell lines exhibited a low to moderate α/β ratio, with the mean being 3.27. Two cell lines exhibited statistically increased survival at 4 and 24 h in the dose-response assay. Overall, our results indicate that the cell lines are moderately radioresistant, have a high repair capacity and behave similarly to a late-responding normal tissue. These findings indicate that the radiation protocols utilizing higher doses with less fractionation may be more effective for treating TCC.     

应用隶属函数法综合评价葡萄种间抗寒性

在冷冻胁迫条件下,测定了葡萄属12个种45个株系枝条的膜透性变化、含水量动态变化及萌芽能力3项指标,并以种内不同株系间3项指标的平均值综合评价了12个种的抗寒性。结果表明,我国葡萄属野生种(东亚种群)山葡萄、燕山葡萄以及美洲种群中的河岸葡萄为高抗类型;蘡薁葡萄、复叶葡萄、毛葡萄为中抗类型;秋葡萄、刺葡萄、瘤枝葡萄为低抗类型;秦岭葡萄、麦黄葡萄和欧洲葡萄为不抗类型。抗寒性指标间相关性分析表明,利用平均隶属度评价葡萄抗寒性最为科学,为鉴定葡萄新种质提供了依据。     

17S U2 snRNP中不可或缺的剪接因子SF3a的研究进展

剪接体由snRNPs(small nuclear ribonucleoprotein particles)和非snRNPs蛋白质组成,能通过剪接作用对内含子进行精确切除,形成成熟有活性的mRNA。SF3a是哺乳动物U2型主要剪接体中不可或缺的成分,参与形成有活性的17S U2 snRNP,由SF3a60、SF3a66、SF3a120构成。SF3a120与SF3a60和SF3a66互作,但SF3a60与SF3a66并不互作。文中对17U2 snRNP中的剪接因子SF3a的研究进展进行了阐述,证明了SF3a对于细胞的形态、分化、正常的生长发育具有重要作用。     

水稻秸青贮对反刍动物甲烷排放的影响

采用2个3×3拉丁方试验设计,利用SF6示踪技术分别测定了青年母牛不同饲养水平(维持和生长)下饲喂青贮稻秸、氨化稻秸以及干稻秸的甲烷排放量,从而评价了水稻秸青贮在减少甲烷排放量上的作用。结果表明:维持水平下,饲喂青贮稻秸和氨化稻秸可有效地降低试验牛每天的甲烷排放以及每千克干物质采食量的甲烷排放,并且与干稻秸组之间差异显著(P<0.05)。甲烷排放量由大到小为干稻秸、氨化稻秸、青贮稻秸。生长水平下,粗饲料的瘤胃降解率越高,日粮中添加精料越有助于纤维的发酵,表现为单位(每天或者每采食1 kg干物质)甲烷气体排放青贮稻秸组均高于干稻秸组。     

放牧条件下白牦牛采食的季节性微调整及其效应

为研究牦牛采食模式季节性微调整对摄入的干物质及胃肠道甲烷排放的效应,于2014年9月至2015年9月进行了天祝白牦牛采食试验。结果表明：卷食模式的7?8月,蛋白质摄入最高（10.70%±0.38%）、粗纤维（18.68%±5.31%）和木质素摄入（1.89%±0.49%）最低、反刍间隔最短（1.1±0.3h）。啃食和卷食相结合的4月份半纤维素（15.68%±5.17%）和粗脂肪（1.08%±0.09%）摄入最低;5月份采食速度最快（1.15±0.16口/s）;6月份粗灰分摄入最高（18.29%±2.39%）、胎儿出生质量最大;9月份单口采食（1.97±0.27 g）、脂肪摄入量（3.77%±0.08%）、日增质量（97.43±5.18 g/d）、瘤胃甲烷气体排放最高（315.70±21.24 g/d）;10月份日采食总量（9749.40±2783.66g/d）、反刍速度最高（1.24±0.15团/min）;11月份半纤维素摄入最高（19.46%±2.58%）;12月反刍间隔最长（2.9±0.2h）。啃食模式的2月份单口采食量（0.95±0.14g）、采食速度（0.73±0.24口/s）、蛋白质（2.72%±0.49%）、粗灰分摄入（7.14%±3.25%）最低;3月份纤维素（39.25%±7.15%）、木质素（12.57%±0.46%）摄入量为最高,日采食量（4417.29±1114.56 g/d）、反刍速度（0.76±0.16团/min）、日增质量（?48.87±3.56 g/d）、瘤胃甲烷量排放（237.57±22.39 g/d）最低;该研究以解释牦牛生产过程中季节性甲烷排放节律。     

TGIF1 and SF1 polymorphisms are associated with litter size in Small Tail Han sheep

TGF-β induced factor homeobox 1 (TGIF1) and splicing factor 1 (SF1) are important for mammalian reproduction; however, the effects of these genes on litter size in sheep remain unexplored. In this study, we genotyped 768 ewes from seven sheep breeds at two loci: g.37871539C>T, a synonymous mutation of TGIF1; and g.42314637T>C, a 3′UTR variant of SF1. Our analysis of polymorphism revealed only two genotypes at locus g.37871539C>T in TGIF1, with most sheep populations being moderately polymorphic (0.25 < PIC < 0.5) at this site. In contrast, most breeds exhibited low polymorphism (PIC ≤0.25) at the SF1 locus g.42314637T>C. The association analysis revealed that a synonymous mutation at g.37871539C>T in TGIF1 was highly associated with litter size in Small Tail Han sheep, in which it causes a significant decrease in litter size. Conversely, while the SF1 3′UTR variant g.42314637T>C was also highly associated with litter size in sheep, it causes a significant increase in the number of litter size. Combined, these data provide valuable information regarding candidate genetic markers for sheep breeding programs.     

低温胁迫下3个甜角品种幼苗的抗寒性研究

以甜角品种PRAKAYTONG(闪金)、SRITONG(金色)、SRITONGBAO(轻金色)的1年生嫁接苗为材料,采用人工气候箱连续15 d分别进行5、10、15、20、25、30℃的温度处理,测定分析了低温胁迫下甜角幼苗叶片与抗寒性相关的生理生化指标。结果表明:20 30℃是甜角生长发育的最适温度范围,当温度下降到15℃时,随着温度的降低,甜角幼苗叶片的相对电导率、丙二醛(MDA)含量、脯氨酸含量、可溶性糖含量呈上升趋势,过氧化物酶(POD)活性表现出先升后降趋势,叶片含水量呈现下降趋势;温度降到10℃时,幼苗叶片上述指标变化加剧,幼苗生长发育受到抑制。在相同的低温条件下,随着处理时间的延长,幼苗叶片的上述6个指标呈现相似的变化趋势,温度越低,变化越剧烈。根据隶属函数法,综合判定3个甜角品种的抗寒性强弱的顺序为:SRITONG>SRITONGBAO>PRAKAYTONG。