季节对延边黄牛卵母细胞质量及体细胞核移植胚胎发育的影响

研究季节对延边黄牛卵巢质量和卵母细胞的数量、质量、体外成熟以及核移植重组胚发育的影响。持续1年采集延边黄牛卵巢,分级卵巢,抽取卵巢表面直径2～8mm的卵泡内的卵母细胞,收集后进行体外成熟和重组胚的体外培养。结果表明,1级卵巢的比例在春冬季时明显高于秋季（P〈0．05）,2级卵巢的比例在春夏季高于冬季（P〈0．05）,秋季的3级卵巢比例最高,与其他季节有显著差异（P〈0．05）;在秋冬季,平均每个卵巢拣出卵母细胞数高于春夏季（P〈0．05）,成熟率上,秋季显著高于春夏季（P〈0．05）,但与冬季并无差异且其他各组间无显著差异（P〉0．05）;卵裂率上,秋季与春季有差异（P〈0．05）,但与其他季节无显著差异（P〉0．05）,囊胚率上,各组之间均无显著差异（P〉0．05）。通过研究发现,季节对延边黄牛卵母细胞的可用回收数量及其质量都会产生影响且秋季为延边黄牛体细胞核移植实验最适合季节。     

吸积盘辐射的高发射率指数研究

在磁场提取黑洞旋转能量的统一模型基础上,给出了MC过程的功率和力矩表达式;并计算了MC过程情况下吸积盘辐射的高发射率指数α.通过研究发现,XMM-Newton天文卫星对Seyfert-1型MCG-6-30-15星系观测到的发射率指数能很好地被有MC过程情况下的薄盘辐射所拟合.     

磁场提取ADAF中心黑洞能量研究

利用 ADAF(advection-dominated accretion flow,径移主导吸积流)的自相似解,推导出了磁场提取 ADAF 中心黑洞能量的功率表达式,研究了黑洞的自转 a_*和径移主导参数ε′对功率的影响,并用该功率拟合了另一类活动星系核——BL Lac 天体的射电喷流功率值。结果表明,在吸积率一定的情况下,该功率主要决定于 a_*,对ε′不敏感,且计算得到的功率能很好地拟合喷流功率的观测数据值。     

建立种猪核心群提高商品猪质量的研究

在广西１０个工厂化猪场进行了提高商品猪质量的研究。通过建立种猪核心群，种猪综合指数选择，严格选种选配，使种猪生产性能和肉猪肥育性能，以及体型外貌的整齐度都有较大的改善。１９９３年与１９９１年比较，长白猪核心群产仔数提高５．８％，２８日龄断乳重提高７．６％，商品杂交猪日增重提高１２．６％，料重比降低５．９％。经ｔ测定，多数经济性状Ｐ＜０．０１，差异高度显著。１０个猪场每年产仔数增加４９６８头，可节约种猪料２０万ｋｇ；每头商品猪可增加活重７．４ｋｇ，每年可增加活重７２．７４万ｋｇ，取得了显著的经济效益和社会效益。     

Microinjection of AT1 and AT2 receptor antagonists into PVN affects renal sympathetic nerve activity in chronic heart failure rats

AIM: To examine the renal sympathoexcitation affected by microinjection of angiotensin Ⅱ type 1 (AT₁) receptor antagonist L-158809 and angiotensin Ⅱ type 2 (AT₂) receptor antagonist PD123319 into paraventricular nucleus (PVN) in heart failure rats.METHODS: Left anterior descending coronary artery ligation was used to induce rat heart failure (HF) . Four weeks after operation, the left ventricular end-diastolic pressure (LVEDP), the ratios of heart weight/body weight and lung weight/body weight, and the ratio of infarct area of the left ventricle were observed. Under anesthesia, SD rats were fixed into the brain stereo controller to locate PVN for microinjection and the artificial cerebrospinal fluid (ACSF) was used for control. The left kidney was exposed by retroperitoneal approach and the renal sympathetic nerve was separated under surgical microscope. The heart rate, blood pressure and the activity of renal sympathetic nerve discharge (RSNA) were recorded by POWERLAB 8/30 system. RESULTS: Microinjection of AT₁ receptor antagonist into PVN induced a decrease in RSNA in both HF rats and sham rats. The RSNA responses to L-158809 in the HF rats were significantly greater (P<0.05) than those in the sham rats. However, microinjection of AT₂ receptor antagonist and ACSF into PVN induced no change of RSNA in both HF and sham rats. CONCLUSION: There are some differences of sympathetic nerve outputs between using AT₁ receptor antagonist and AT₂ receptor antagonist on PVN, indicating the up-regulation of AT₁ receptors in PVN during HF. The central renin-angiotensin-aldosterone system(RAAS) may be affected by AT₁ receptor, not by AT₂ receptor.     

Equine cervical intervertebral disc degeneration is associated with location and MRI features

Morphology of the equine cervical intervertebral disc is different from that in humans and small companion animals and published imaging data are scarcely available. The objectives of this exploratory, methods comparison study were (a) to describe MRI features of macroscopically nondegenerated and degenerated intervertebral discs (b) to test associations between spinal location and macroscopic degeneration or MRI‐detected annular protrusion and between MRI‐detected annular protrusion and macroscopic degeneration, and (c) to define MRI sequences for characterizing equine cervical intervertebral disc degeneration. Ex vivo MRI of intervertebral discs was performed in 11 horses with clinical signs related to the cervical region prior to macroscopic assessment. Mixed‐effect logistic regression modeling included spinal location, MRI‐detected annular protrusion, and presence of macroscopic degeneration with “horse” as random effect. Odds ratio and 95% confidence interval were determined. Reduced signal intensity in proton density turbo SE represented intervertebral disc degeneration. Signal voids due to presence of gas and/or hemorrhage were seen in gradient echo sequences. Presence of macroscopic intervertebral disc degeneration was significantly associated with spinal location with odds being higher in the caudal (C5 to T1) versus cranial (C2 to C5) part of the cervical vertebral column. Intervertebral discs with MRI‐detected annular protrusion grades 2‐4 did have higher odds than with grade 1 to have macroscopic degeneration. It was concluded that MRI findings corresponded well with gross macroscopic data. Magnetic resonance imaging of the equine cervical intervertebral disc seems to be a promising technique, but its potential clinical value for live horses needs to be explored further in a larger and more diverse population of horses.     

新疆细毛羊超排胚胎移植核心群育种方案的确定

南山种羊场的育种方案是根据育种目标的4个选择标准，加权综合而形成。计算出的选择指数为：净毛质量＋21.08；毛束长度＋0.58；平均纤维直径-4．23；育成羊体质量＋1.47。估测该方案每世代遗传进展为16～2．1，选择指数标准差依MOET功率而定，与传统的育种改良方案（每世代遗传进展约为选择指数标准差）相比非常有益。     

家禽动眼神经核簇的细胞构筑及其5-HT神经元的分布

用Nissi染色法和免疫组化SP法研究鸡、北京鸭、鸽子的动眼神经核簇细胞构筑及5-羟色胺神经元分布情况，结果表明：北京鸭的动眼神经核簇系由动眼神经核、E—W核和前背外侧核3个部分所构成，而在鸡和家鸽仅包括动眼神经核和E—W核。他们的核团形态和细胞构筑基本相同。观察到5-HT阳性神经元在鸡、鸭和鸽子动眼神经核及鸡E—W核内的分布，而在鸭和鸽子的E—W核和鸭的前背外侧核内却未见分布。动眼神经核5-HT阳性神经元的数量较多，在各个亚核的分布均匀，胞体着色较深。     

金针菇转核育种研究

从金针12（黄色）次级菌丝提取细胞核，分别与白色金针菇白雪和白色糙皮侧耳原生质体在高钙、高PH条件下融合。对再生菌丝的研究结果表明，无锁状联合的单核菌丝不形成子实体，但双核化后形成的具有锁状联合的双核菌丝则具有形成子实体的能力。试验结果显示，金针12与白雪组合后代均为黄色金针菇；而金针12与白色糙皮侧耳组合后代中，大多数菌株形成的子实体形态与白色糙皮侧耳类似，仅1%-2%菌株形成的子实体形态与白色金针菇类似。     

Downregulated transient outward potassium channel protein Kv4.2 and Kv4.3 expression in PVN contributes to sympathoexcitation in rats with chronic heart failure

AIM: To investigate the transient outward potassium channel protein expression in paraventricular nucleus(PVN) and its contribution to renal sympathetic nerve activity(RSNA) in rats with chronic heart failure(CHF).METHODS: A rat model of CHF was prepared by acute myocardial infarction that was induced by ligation of the left anterior descending coronary artery. Four weeks after heart failure, echocardiogram was applied to identify the CHF model and plasma norepinephrine(NE), serum NH₂-terminal pro-brain natriuretic peptide(NT-proBNP) were detected by ELISA. The expression of ransient outward potassium channel proteins Kv4.2 and Kv4.3 at mRNA and protein levels was determined by real-time PCR and Western blot. The mean arterial pressure(MAP), heart rate(HR) and RSNA were measured in anesthetized rats with PVN microinjection of potassium channel blockers 4-AP. RESULTS: In CHF group, the rat cardiac function and Kv4.2 and Kv4.3 expression in PVN were obviously lower while plasma NE and serum NT-proBNP were obviously higher than those in sham group. Microinjection of 4-AP into PVN induced an increase in MAP, HR and RSNA in both sham and CHF rats, while the CHF rats exhibited smaller responses to 4-AP than sham-operated rats.CONCLUSION: Downregulation of Kv4.2 and Kv4.3 expression in the PVN may be a potential mechanism for sympathoexciation in the rats with chronic heart failure.