术前静脉造影对静脉管壁及其吻合效应的实验研究

以动物实验模拟行静脉造影后,肉眼观察,并以透射电镜和扫描电镜动态观察经灌注固定的局部静脉管壁和内皮细胞的改变,发现造影剂回流的静脉管壁在较长的时间内处于扩张状态,同时穿刺注射造影剂的部位出现较严重的淤血和血栓形成。内皮细胞连接有较广泛裂开、剥离及内皮下组织暴露。在受损严重的区域还可见有微血栓形成。造影1天后内皮细胞受损最为严重,至第3天基本恢复。血管吻合实验表明,术前3天静脉造影不影响直径为2.5mm静脉的吻合通畅率。     

The Influence of Intramammary Lipopolysaccharide Infusion on Serum Ca,P, Vitamin D,Cytokines and Cortisol Concentrations in Lactating Sows

Ten multiparous lactating sows were used to investigate whether intramammary infusion of lipopolysaccharides (LPS; Escherichia coli 0111:B4; 2.0 μg/kg of body weight) would affect the circulating concentrations of Ca, P, 25‐hydroxyvitamin D (25‐OHD), tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6) and cortisol. The sows were randomly allotted to either control group (control) or LPS‐treated group with five individuals per group and were infused with either physiological saline solution or LPS solution. The rectal temperature and udder quarter appearance were recorded at 0 (just before infusion), 1, 3, 7, 12 or 24 h after infusion. Blood samples were taken at 0, 1, 3, 7, 12 or 24 h after infusion. Before infusion, the rectal temperatures of all sows were below 39.2°C. At 3 and 7 h after infusion, the sows in the LPS group had a rectal temperature over 39.4°C. At 24 h after infusion, the rectal temperatures returned to pre‐infusion levels. Serum Ca and P concentrations in the LPS group decreased (P < 0.05) after LPS infusion compared with the control group at 1 h after infusion. No significant differences (P > 0.05) in the concentrations of 25‐OHD were observed between groups control and LPS at any sampling time. Increased (P < 0.01) concentrations of serum TNF‐α, IL‐6 and cortisol were observed in the LPS group compared with the control group at 3 and 7 h after infusion respectively. In conclusion, the elevation of serum concentrations of TNF‐α, IL‐6 and cortisol and the alterations of circulating concentrations of Ca and P following LPS infusion indicate that the immune system has been activated and immune activation may affect macromineral homeostatic regulation, which might have important implications for metabolic health of lactating sows. Lowered serum Ca and P following immune activation also shows a causative mechanism whereby immune activation increases the risk of secondary disorders such as mastitis‐metritis‐agalactia syndrome. However, immune activation did not affect circulating concentrations of vitamin D metabolites.     

人心肌肌钙蛋白I第2和第4个密码子同义突变对其在大肠埃希菌中表达的影响

目的 对人心肌肌钙蛋白I（cTnI）基因实行定点突变并进行原核表达，观察此突变对cTnI表达量的影响。方法 利用RT-PCR方法从人心肌细胞的总RNA中克隆出编码人心肌肌钙蛋白I的cDNA片段，设计引物将其第2和第4个密码子突变后插入原核表达载体形成重组体，并导人宿主菌BL21（DE3）中，经IPTG诱导表达，Ni-NTA树脂纯化后行Western blot鉴定，观察突变对cTnI表达的影响。结果 突变后的cTnI基因与对照组相比在大肠埃希菌中得到高效表达，经纯化可获得电泳单点纯的cTnI蛋白。结论 成功克隆了cTnI基因，所设计的同义突变可促进cTnI在大肠埃希菌中的高效表达。     

重组2型腺相关病毒-转化生长因子β3对实验性肝纤维化大鼠肝脏组织病理学和Ⅰ型胶原表达的影响

Objective To investgate the effects of TGF β 3 on rat hepatic fibrosis. Methods The TGF β 3 cDNA was cloned into rAAV2 vector. Rats were randomly divided into four groups: normal control group, model group, negative control group and TGF β 3 group. Hepatic fibrosis was induced by hypodermic injection of 40% CCI4. Recombinant AAV2-TGF β 3 viral particles were injected via the vena caudalis one week before CCh treatment. Rats were executed 8 weeks after CCI4 treatment, global histological change was observed after HE staining, the distribution of the collagen fibers was observed after masson staining, his-tochemistry was done to observe the expression of collagen Ⅰ; The positive area rate of the collagen fibers and the average optical rate of collagen Ⅰ were quantified. Results HE staining indicated that collagen fibers were reduced in the TGF β 3 group. Masson staining shown that the collagen fibers were distributed around the blood vessel, in the portal area and disse space. Compared to the model group (13.2%±2.2%) and negative control group (12.3%±1.5%), the collagen fibers in liver tissues of TGF β3 group (7.7% ± 1.5%) were significantly decreased (q = 9.456, P < 0.01; q = 8.217, P < 0.01). Histochemistry indicated that the collagen fibers of liver tissues of TGF 15 3 group (0.185±0.033) were significantly higher than those in the model group (0.252±0.042) and the negative control group (0.230±0.029), (q = 6.228, P < 0.01; q = 4.346, P < 0.01). Conclusion TGF β 3 alleviates the damage to hepatic cell and the level offibrosis in CCI4 treated rats and inhibits the expression of collagen Ⅰ.     

高效液相色谱法测定去氧氟尿苷含量及其有关物质

目的 用高效液相色谱法（HPLC法）测定去氧氟尿苷的含量及其有关物质。方法 采用Diamonsil C—粒（250mm×4．6mm，5μm），流动相为乙腈-水（1：1），检测波长为269nm，流速为0．8mL／min。结果 去氧氟尿苷质量浓度在10．0～200．4μg／mL范围内与峰面积线性关系良好，r：0．9999（n：5），平均回收率为100．2％，RSD=0．14％。结论 HPLC法简便、准确，专属性好，灵敏度高，可用于去氧氟尿苷含量及有关物质的测定。     

金属基底上聚合吡咯的电化学及电镜表征

用循环伏安法研究了吡咯在不同金属基底不同支持电解质中的聚合过程，对不同基底上制备的聚吡咯膜进行了电化学、扫描电镜、表面能谱等方面的研究，考察了聚吡咯膜电极对ＮＯ_３－离子的电位响应情况，结果表明，不同基底不同支持电解质在不同的吡咯浓度中表现出各异的伏安行为，经电化学处理的聚吡咯膜电极均对ＮＯ_３－呈Ｎｅｒｎｓｔ响应，扫描电镜观察表明除Ｐｔ基底外在其它基底上制备的聚吡咯膜均呈颗粒性球状堆集。     

左旋肉毒碱对人成骨细胞增殖和凋亡的影响

目的观察左旋肉毒碱(L-carnitine,L-C)对人成骨细胞增殖和凋亡的作用。方法以3H掺入法(3H-TdR)测定左旋肉毒碱对人成骨细胞增殖的影响;以吖啶橙/溴化乙啶染色和细胞凋亡ELISA(酶联免疫吸附法)试剂盒测定左旋肉毒碱对人成骨细胞凋亡的影响;以免疫印记法检测左旋肉毒碱干预前后活化型Caspase-3、-9蛋白质表达水平的改变。结果10~100mmol/L左旋肉毒碱能促进人成骨细胞增殖。吖啶橙/溴乙啶染色法示100mmol/L左旋肉毒碱干预使人成骨细胞凋亡细胞明显减少。ELISA结果示10~100mmol/L左旋肉毒碱干预可显著抑制人成骨细胞凋亡。10~100mmol/L左旋肉毒碱干预可抑制无血清饥饿诱导的人成骨细胞caspase-3、9活化增加。结论左旋肉毒碱促进人成骨细胞增殖,并通过下调Caspase-3、-9的活化抑制人成骨细胞凋亡。     

环隙气升式反应器在非牛顿流体体系中的应用──反应器特性研究和体积氧传递系数的关联

以羧甲基纤维素钠（ＣＭＣ）水溶液模拟非牛顿型发酵介质，在内径为０．１５ｍ，高为０．９７５ｍ的环隙气升式反应器内，考察了液体流变性质和导流筒结构对气液传质的影响，提出了体积氧传递系数（ＫＬａ）的经验关联式。实验表明：对于较高粘度的假塑性流体，反应器内部采用整体式导流筒结构，将有利于传质和混合，其性能优于采用开窗式导流筒或无导流筒的反应器。     

人重组C3片段通过IL-2自分泌效应对CTLL-2细胞产生促增殖作用

目的研究补体Ｃ３片段的体外生物学活性及其作用机理，进一步探讨Ｃ３片段与免疫细胞的关联。方法利用重组ＤＮＡ技术表达纯化Ｃ３活性片段（命名为Ｃ３３），观察其对ＩＬ－２依赖性的小鼠杀伤性Ｔ细胞株ＣＴＬＬ－２细胞的促增殖效应，并通过抗体封闭途径和分子杂交技术研究Ｃ３３作用的机理。结果发现Ｃ３３蛋白对ＣＴＬＬ－２细胞具有明显的促增殖作用，并呈剂量依赖关系；这一作用能够部分地被抗小鼠ＣＤ１１ｂ抗体所封闭，能够完全被抗小鼠ＩＬ－２抗体所封闭；分子杂交显示Ｃ３３蛋白能够明显刺激ＣＴＬＬ－２细胞的ＩＬ－２ｍＲＮＡ表达。结论人重组Ｃ３片段Ｃ３３可通过ＩＬ－２的自分泌效应对ＣＴＬＬ细胞产生促增殖作用，补体受体ＣＲ３参与这一作用。     

扩散管配制甲醛标准气体的研究

介绍了扩散法配制标准气体的方法。以三聚甲醛为原料，通过加热催化分解三聚甲醛蒸气，来配制甲醛标准气体。讨论了配制甲醛标准气体的准确性、稳定性、重复使用性，以及温度、扩散管几何尺寸、载气气流、配气源物质的量等因素对三聚甲醛扩散率的影响。本方法制备的甲醛标准气体，扩散率（２～５０μｇ／ｍｉｎ）测定总不确定度小于５％。