幼龄贵州小型猪主要脏器重量及脏器系数的测定

目的测定幼龄贵州小型猪脏器重量、脏器系数的生物学特性指标。方法选用初生(0 d)和一月龄(30 d)普通级贵州小型猪各20只,雌雄各半,分别测定体重和10个脏器重量,计算脏器系数。结果雌雄贵州小型猪初生组体重、肝重量、肾重量、胃系数差异均有极显著性(P<0.01),胃、心重量有显著性差异(P<0.05),而一月龄组雌雄体重和脏器重量均无显著性差异(P>0.05),肺系数有极显著性差异(P<0.01)。结论雌雄幼龄贵州小型猪的体重、肝重量、胃重量、心重量、肾重量、胃系数、肺系数具有差异。     

我国生猪价格波动的系统动力学仿真与对策分析

在分析和归纳现有文献对生猪价格波动研究的基础上,分析了生猪价格波动的结构性原因,并构建了因果分析图和系统动力学流图;在此基础上,建立了系统动力学模型,并进行了仿真分析.结果表明:生产延迟和较大的供给价格弹性是生猪价格大幅波动的本质因素;政府的冻肉收储和母猪保险补贴等政策并不能改变生猪价格大幅波动的规律;只有通过提高生猪饲养规模程度和专业化程度,并配合生猪期货交易,以降低生猪价格供给弹性,才能从根本上改变生猪价格大幅度波动的规律.     

豚鼠性周期阴道细胞变化的研究

目的准确确定豚鼠性周期各个阶段。方法利用阴道组织涂片法,对16只12周龄的雌性豚鼠连续20 d 进行阴道涂片。镜检,观察阴道涂片中细胞的变化以及豚鼠性周期各阶段的持续时间。结果在发情间期,阴道涂 片以白细胞为主;发情前期,以有核上皮细胞为主;在发情期,以角质化的上皮细胞为主;发情后期白细胞中混有部 分有核上皮细胞和少量角化上皮细胞。结论阴道组织涂片法是有效区分豚鼠性周期各个阶段的一种简单方法。     

猪血超氧化物歧化酶纯化与分析─—一种铜盐沉淀新工艺

本文建立铜盐沉淀、选择热变性、ＳｅｐｈａｄｅｘＧ—１００层析方法从猪血中提纯超氧化物歧化酶，纯化倍数１８６．５．该酶在聚丙烯酰胺凝胶电泳中呈一蛋白带．纯酶的比活性为９３２５ｕ／ｍｇ—ｐｒ（邻苯三酚—３２５法）．通过ＳＤＳ—ＰＡＧＥ法测出分子量为３００００．该酶对热稳定，纯酶液的最大吸收波长为２６０ｕｍ．     

DNA fragmentation in leukocytes following subacute lowdose nerve agent exposure

The objective of the present study was to determine levels of DNA fragmentation in blood leukocytes from guinea pigs by single-cell gel electrophoresis (comet assay) after exposure to the chemical warfare nerve agent (CWNA), soman, at doses ranging from 0.1 LD₅₀ to 0.4 LD₅₀, once per day for either 5 or 10 days. Post-exposure recovery periods ranged from 0 to 17 days. Leukocytes were imaged from each animal, and the images analyzed by computer. Data obtained for exposure to soman demonstrated significant increases in DNA fragmentation in circulating leukocytes in CWNA-treated guinea pigs compared with saline-injected control animals at all doses and time points examined. Notably, significantly increased DNA fragmentation was observed in leukocytes 17 days after cessation of soman exposure. Our findings demonstrate that leukocyte DNA fragmentation assays may provide a sensitive biomarker for low-dose CWNA exposure.Received 29 July 2003; accepted 14 August 2003     

Identification of the bioactive peptide PEC-60 in brain

PEC-60 is a 60-residue peptide originally isolated from pig intestine. It inhibits glucose-induced insulin secretion from perfused pancreas in a hormonal manner and also has biological activity in the immune system. PEC-60-like immunoreactive material has been reported in catecholamine neurons of the central and peripheral nervous systems, but the peptide has not been identified from that material. We have now isolated PEC-60 from pig and rat brains with a method that combines column purification procedures with the specificity of a radioimmunoassay and the sensitivity of mass spectrometry to directly identify the peptide. The results show that PEC-60, like many other peptides, is expressed in the gastrointestinal tract and the central nervous system. The specific regional brain distribution and interaction with classical neurotransmitters raise the possibility that PEC-60may play a role in the central nervous system disorders involving dopamine dysregulation. Received 6 December 2002; received after revision 10 December 2002; accepted 11 December 2002 RID="*" ID="*"Corresponding author.     

野猪资源的保护和利用研究

从野猪染色体遗传标记的角度，论述了野猪与家猪杂交的可能性，并对野猪的肉用性能做了初步分析，其氨基酸含量丰富，必需氨基酸种类齐全，肌间脂亚油酸含量达１７．３６％．提出了野猪资源进一步利用的途径和方式，为野猪资源的开发利用提出了新的思路．     

3-甲基组氨酸三室模型在研究猪骨骼肌蛋白质降解中的应用

3-甲基组氨酸(3MH)主要是动物骨胳肌蛋白分解代谢产物，它不能再用于合成蛋白，因而3MH是研究动物骨胳肌蛋白降解率的一个可行示踪物．将标记的3MH经颈静脉注射，对血液中的同位素丰度进行观测，再根据猪体内3MH代谢特点，构建出猪骨胳肌蛋白降解的三分域模型．本文着重对该模型的的理论基础进行了讨论。     

The effects of acute and chronic morphine on regional distribution of cardiac output in brain

Summary Both acute and chronic administration of morphine resulted in an increase in the percent cardiac output received by brain. However, various brain regions were affected differently by the drug treatments. The greatest increases in percent cardiac output received after chronic administration of morphine occurred in pons and cerebellum, while the greatest increases after acute administration occurred in cortex and midbrain. The changes found are in contrast with earlier studies which suggest that morphine has no effect on cerebral blood flow.     

Seasonal influence on the development of parthenotes and cloned embryos in pigs

Seasonal influence on the developmental ability of porcine embryos was studied by comparisons of the number of cumulus-oocytes-complexes (COCs) per ovary pair and meiotic maturation ability of oocytes in different seasons; and by the observations on developmental competence of the parthenogenetic oocytes and cloned embryos collected from different seasons. We found that the number of COCs per ovary pairs was significantly higher in spring compared to the other seasons (P<0.05). However, no significant difference was found in the rate of oocytes progressing to MⅡ in four seasons (P<0.05). In addition, the rate of blastocyst formation of parthenogenetic embryos in summer was obviously declined compared to the other seasons (P<0.05), and an increased blastocyst rate of cloned porcine embryos was found in spring compared to autumn and winter (P<0.05). The results suggest that there should be a seasonal influence on the developmental competence of porcine embryos.