毒害艾美耳球虫初次感染雏鸡免疫器官IL-2和淋巴细胞增殖功能变化

应用组织匀浆涂片和酸性α-醋酸萘酯酶（ANAE）染色及细胞培养技术和四甲基偶氮唑盐（MTT）测定法对毒害艾美耳球虫（eimeria necatrix，E．necatrix）初次感染雏鸡免疫器官的T细胞比例、白细胞介素-2（interleukin-2，IL-2）诱生活性、T细胞和B细胞对ConA或PMA的增殖功能的动态变化进行了较全面系统的研究。结果发现，E．necatrix初次感染雏鸡，其胸腺和脾脏T细胞比例分别于感染后7～21d和7～24d明显高于对照雏鸡；IL-2诱生活性分别于感染后16～18d和18～21d较对照雏鸡显著升高；T细胞对ConA的增殖反应分别在感染后14～16d和10～18d明显增加。法氏囊和脾脏B细胞对PMA的增殖反应分别于感染后14～24d和14～21d显著高于对照雏鸡。表明E．necatrix初次感染雏鸡免疫器官的IL-2调节及细胞免疫和体液免疫功能均明显提高。     

Partial pressure of end-tidal CO2 sampled via an intranasal catheter as a substitute for partial pressure of arterial CO2 in dogs

Objective: To demonstrate correlation and clinical usefulness of the partial pressure of end‐tidal CO₂ (ETCO₂) measurement by nasal catheter placement in sedated dogs with and without concurrent nasal oxygen administration as a substitute for partial pressure of arterial CO₂ (PaCO₂). Design: Prospective, cross‐over trial. Setting: University of Saskatchewan veterinary research laboratory. Animals: Six cross‐breed dogs with a mean (±SD) weight of 29.1±4.03 kg. Interventions: All dogs were sedated with 5 μg/kg medetomidine intravenously (IV) and an arterial catheter was placed in a dorsal pedal artery for removal of blood for gas analysis. A nasal catheter was placed in the ventral meatus and connected to a capnometer for ETCO₂ measurements in all dogs. Dogs receiving supplemental nasal oxygen had a second nasal catheter placed in the contralateral naris. Measurements and main results: In the group without nasal oxygen supplementation, the ETCO₂ measurement underestimated (negative bias) the PaCO₂ by ?2.20 mmHg with limits of agreement (95% confidence interval) of ?5.79, 1.39 mmHg. In the group receiving oxygen supplementation, ETCO₂ measurement underestimated (negative bias) the PaCO₂ by ?2.46 mmHg with limits of agreement (95% confidence interval) of ?8.42, 3.50 mmHg. Conclusions: The results of this study demonstrate that ETCO₂ monitoring via a nasal catheter provides a clinically acceptable substitute to arterial blood gas analysis as a means of monitoring ventilation in healthy, sedated dogs. The limits of agreement were within acceptable limits with and without concurrent insufflation of oxygen.     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

灭虫精对西施舌幼贝的毒性试验

在静水条件下,进行灭虫精对西施舌幼贝的毒性试验,试验结果显示:灭虫精对西施舌幼贝24 h致死浓度LC100为400 ms／L,半数致死浓度LC100为250 mg/L,安全浓度为2．50mg／L;48h致死浓度为260 mg／L,半数致死浓度LC50为224ms／L,安全浓度为2．24mg／L。灭虫精用于西施舌人工育苗过程中桡足类等敌害生物防治,具有较强的可用性。根据试验结果,建议使用2 mg／L浓度的灭虫精进行防治,可达到显著效果。     

快速测定预混合饲料中维生素B2的含量

采用荧光标准曲线法对预混合饲料中维生素B2进行测定.本法测定线性范围较宽,在0.0～1.0 μg/mL相关系数为0.99998, 平均回收率为94.55%～102.86%.本法简单快捷,能满足预混合饲料中维生素B2的分析要求.     

PRRSV与PCV2体外共感染对猪肺泡巨噬细胞免疫学功能的影响

制备猪肺泡巨噬细胞,分别接种PCV2、PRRSV、PCV2 PRRSV(先接种PCV2,12h后接种PRRSV)、PRRSV PCV2(先接种PRRSV,12h后接种PCV2)、PRRSV/PCV2(同时接种)和对照组。接种后不同时间观察细胞病变(CPE),并用real-time PCR和IFA方法检测PRRSV和PCV2滴度,INF-α、INF-γ、TNF-α、IL-8和IL-10的mRNA。结果为:①PRRSV能在PAM中增殖,有CPE;PCV2在PAM中感染率较低,无CPE。②PRRSV对PCV2增殖无明显影响。PCV2先于或同时与PRRSV感染对PRRSV的复制具有抑制作用,而PCV2后于PPRSV感染,可促进PRRSV增殖。③PCV2单独感染PAM后能促进INF-α、INF-γ、IL-8和IL-10的大量表达,对TNF-α的表达量影响不大。④PCV2与PRRSV混合感染,尤其是PCV2后于PRRSV感染后,TNF-α、IL-8和IL-10的表达量与单感染组相比明显增加,而INF-γ的表达量明显受到抑制。实验结果表明,PCV2感染时间对PRRSV的增殖影响不同,PRRSV感染后如果再感染PCV2,可以明显促进PRRSV病毒增殖;两种病毒共同刺激了TNF-α、IL-8和IL-10的大量表达,抑制了抗病毒因子INF-γ的表达,从而可能抑制体液免疫和细胞免疫,加重了病理学免疫应答。     

Prevention of progeny formation in Drosophila melanogaster by 1-arylimidazole-2(3H)-thiones

Effects of 1-arylimidazole-2(3H)-thiones (AITs) and 1-(substituted benzyl)imidazole-2(3H)-thiones (BITs) were tested on progeny formation in Drosophila melanogaster. Some AITs showed inhibitory activities at laying eggs and delayed eclosion by 1 day. The inhibitory activity was nullified by adding octopamine (OA) or noradrenaline (NA) to the medium for progeny formation in D. melanogaster. The effect of AIT on the contents of OA and NA was analyzed in adults of D. melanogaster by high-performance liquid chromatography with electrochemical detection. Flies fed with AIT decreased OA and NA levels and increased TA content. Taken together, the inhibitory activity of AIT could be due to inhibition of tyramine β-hydroxylase and dopamine β-hydroxylase.     

Effects of Momordica grosvenori Saponins on Type 2 Diabetes Rats Induced by High-sucrose/High-fat Diet and Streptozotocin

The purpose of the experiment was to study the effect of Momordica grosvenori saponins on improving the effect of high-sucrose/high-fat diet combined with streptozotocin induced type 2 diabetes in rats.The type 2 diabetes rat model was established with a high-sucrose and high-fat diet combined with streptozotocin.Successfully modeled rats were given the total saponins of Momordica grosvenori (100,200,400 mg/kg) or metformin (268 mg/kg) by gavage,once a day for 4 weeks.Recording the "three more and one less"index (24 h internal urine output,water intake and feed intake,body weight);Detecting of biochemical indicators,analysis of fasting blood glucose (FBG),serum total cholesterol (TC),triglycerides (TG),low-density lipoprotein cholesterol (LDL-C),high-density lipoprotein cholesterol (HDL-C),insulin (INS),catalase (CAT),superoxide dismutase (SOD),malondialdehyde (MDA),alanine aminotransferase (AST),aspartate aminotransferase (ALT),blood urea nitrogen (BUN) and creatinine (Cr) levels.Hematoxylin-eosin staining (HE) was used to observe the pathological changes of the pancreas.Compared with the model group,the feed intake,water intake,urine output,blood indicators FBG,INS,MDA,TC,TG,BUN and Cr levels,AST and ALT activities were significantly or extremely significantly decreased in the total saponins of Momordica grosvenori each dose group and metformin group (P<0.05;P<0.01),while CAT,SOD activities and HDL-C level were significantly or extremely significantly increased (P<0.05;P<0.01).In pancreatic tissue,the number of pancreatic cells was increased significantly,and the pathological damage of the pancreas was significantly reduced. Momordica grosvenori saponins and metformin had obvious effects on improving glucose metabolism disorders,and at the same time could significantly reduce insulin resistance,enhance the body’s ability to resist oxidative stress and improve liver and kidney functions.     

PCV2感染性分子克隆的制备及体内外感染性试验

将猪圆环病毒2型（Type2 porcine circovirus，PCV2）JXL株cDNA插入到载体pMD18-T中，获得的pMDT-PCV转染猪肾细胞PK15细胞系，盲传4代后，利用PCV2阳性猪血清进行间接免疫荧光抗体试验（IFA），能检测到特异性荧光。将pMDT-PCV质粒DNA腹股沟淋巴结注射40日龄仔猪2头，分别接种2、3次，接种剂量500μg／次，首次注射35d心脏放血致死。在体内感染性试验期间，动物未出现明显临床症状。试验结束，病理切片结果显示，不同淋巴组织中分别存在淋巴细胞缺失或增多的现象；肾小球、扁桃体、空肠淋巴结和股前淋巴结等冰冻组织切片中存在大量PCV2病毒抗原；血清中PCV2特异性的ELISA抗体效价迭1：2560，IFA效价为1：1280；通过聚合酶链式反应（PCR）可以分别从体外感染PK15细胞和体内感染动物及同圈饲养的空白对照猪的淋巴组织中扩增到病毒特异性基因片段。本研究证明含有单拷贝PCV2的重组质粒pMDT—PCV在体内、外均具有感染性，能衍生出病毒，并产生符合自然感染PCV2的大体病变和组织病理学变化，并激发较强的体液免癌应答。