猪胸主动脉的零应力状态研究及其临床意义

目的　探讨猪胸主动脉的生物力学特性变化。方法　取 1～ 9月龄猪的胸主动脉各 6例 ,从每例标本的中段处将血管切为短圆环 ;将 7月龄猪胸主动脉分为上、中、下段 ,每段再分为 5个短圆环。将各血管沿其径向剪开 ,测量张开角的大小、壁厚和周长 ,并依周长计算出等效内径。结果　猪胸主动脉张开角由 1月的 (42 .1 7± 4 .0 6)°上升到 7月的 (76.2 2± 4 .4 0 )°,在 7月龄后达到稳定。对 7月龄猪胸主动脉自上而下分析则发现张开角由 (99.73± 6.79)°降至 (42 .0 9± 7.4 0 )°。壁厚 等效内径值随月龄增加而减小 ,于 7月龄后保持于 0 .1 8左右。结论　猪胸主动脉张开角、等效内径和壁厚随月龄的增加而增大 ;随着X L的增加各项指标均逐渐减小 ,血管的内外径在 7月龄后成比例生长。为猪→人异种血管移植和血管的病理改变后修复与功能重建提供依据     

The pig mesonephros

Summary The ultrastructure of the proximal tubule of mature mesonephric nephrons was studied in perfusion-fixed pig embryos of the 41st gestational day. Despite its 8–12 mm long course, the proximal tubule possesses no cytologically different subsegments except its very last cells at the abrupt transition into the distal tubule. The first brush-bordered proximal tubule cells stand considerably within Bowman's capsule, abuting its attenuated cells. In SEM specimens, the average luminal cell diameters are 8×13 m. The cells are 6–11 m in height with overlying microvilli 2–4 long. Lateral faces of perfectly disjoined cells exhibit plate-like interdigitating processes projecting more than 5 m deep into the neighboring cells. The basal cell face is completely covered with microvilli. The TEM pictures reveal an endocytic apparatus largely matching its metanephric counterpart. Mitochondria account for 23% of the cytoplasm and together with the many basolateral cell membranes indicate a high capacity for energy-dependent transport processes. Small basal lipid droplets represent a species peculiarity. Freeze-fracture specimens show an electrocoupling of the cells by gap junctions. The tight junction, with only 1–2 strands, characterizes a leaky epithelium. In most features, this tissue is as mature as its metanephric counterpart.Supported by the Deutsche Forschungsgemeinschaft.     

Oogonia and oocytes degeneration and the nutritive macrophages in the process of the development of the ovary in embryos of the domestic pig (Sus scrofa dom. L.)

Summary In the development the embryonic ovary numerous oogonia and oocytes degenerate. A histochemical study was carried out on the degenerated oogonia and oocytes in different stages of differentiation and development of the ovary in the pig embryos. In the oogonia the degenerative changes include chiefly the chromatin in interphasic and mitotic nuclei. The most numerous degenerations of the nuclei are in meiotic prophase. The degenerative process involves the changes in nuclear volume. Both, the large swollen nuclei, with chromosomes displaced and clustered at one pole, and also the small pycnotic nuclei are observed. Different kinds of oocytes degenerations are discussed.Special attention was paid to the gonadal cord cells and their role in nutrition of gonocytes and in the follicle formation. Some of the cord cells are transformed into macrophages, which ingeste degenerated oocytes. The supposed nutritive functions of these macrophages (nutritive macrophages) are discussed.     

猪IL-2真核表达质粒对猪繁殖与呼吸综合征病毒ORF5基因疫苗诱导小鼠细胞免疫增强作用的研究

目的 :研究猪白细胞介素 2真核表达质粒 (pcDNA IL 2 )对猪繁殖与呼吸综合征病毒ORF5基因疫苗 (pcDNA PRRSV ORF5 )诱导BALB/c小鼠产生细胞免疫应答的影响。方法 :用pcDNA IL 2与PRRSVORF5基因疫苗 (pcDNA PRRSV ORF5 )共同免疫BALB/c小鼠 ,以空载质粒pcDNA为阴性对照 ,PBS为空白对照 ;采用流式细胞仪 (FACS)、淋巴细胞增殖试验(MTT法 )分别对小鼠外周血中CD4 + 、CD8+ T淋巴细胞数和淋巴细胞的转化功能进行了检测。结果 :pcDNA IL 2与pcDNA PRRSV ORF5共同免疫小鼠后外周血对ConA有明显的反应性 ,CD4 + 、CD8+ T淋巴细胞数在免疫后 7天显著超过对照组 ,共同组与单独pcDNA PRRSV ORF5组有显著差异 (P <0 0 1)。结论 :pcDNA PRRSV ORF5免疫小鼠能够诱导其机体产生良好的细胞免疫应答 ,猪pcDNA IL 2能够显著增强pcDNA PRRSV ORF5诱导小鼠细胞免疫的能力。     

Clofibrate treatment up-regulates novel organic cation transporter (OCTN)-2 in tissues of pigs as a model of non-proliferating species

Recent studies have shown that treatment of rodents with agonists of peroxisome proliferator-activated receptor (PPAR)-alpha causes an up-regulation of novel organic cation transporter (OCTN)-2, a carnitine transporter, and increases carnitine concentration in the liver. This study was performed to investigate whether such effects occur also in pigs which like humans have a lower expression of PPAR alpha and are less responsive to treatment with PPAR alpha agonists than rodents. An experiment with 18 pigs was performed which were fed a control diet or the same diet supplemented with 5 g clofibrate/kg for 28 days. Pigs treated with clofibrate had higher relative mRNA concentrations of OCTN2 in liver (3.1-fold), skeletal muscle (1.5-fold) and epithelial cells from small intestine (1.8-fold) than control pigs (P<0.05). Pigs treated with clofibrate had also higher concentrations of free and total carnitine in the liver and a higher concentration of free carnitine in skeletal muscle than control pigs (P<0.05). Concentrations of gamma-butyrobetaine, the precursor of endogenous formation of carnitine, in liver, muscle and plasma did not differ between both groups; the activity of gamma-butyrobetaine dioxygenase, the rate limiting enzyme of carnitine synthesis, in the liver was lower in pigs treated with clofibrate than in control pigs (P<0.05). This study shows for the first time that treatment with a PPAR alpha agonist causes an up-regulation of OCTN2 in liver, muscle and enterocytes from small intestine of pigs. This in turn increases carnitine concentrations in liver and muscle probably by enhancing carnitine uptake into cells.     

肺表面活性物质蛋白A的提纯及其表面活性功能分析

目的　为了提取肺表面活性物质蛋白A ,提高人工合成表面活性物质的疗效。方法　采用萃取和透析的方法提纯肺表面活性物质蛋白A ,并用膜天平检测其生物活性。结果　蛋白质聚丙烯酰胺凝胶电泳显示 ,提纯后的肺表面活性物质蛋白A分子量为 2 9.7× 10 3 ,其杂蛋白条带明显减少 ,将其加入人工合成的磷脂中表现为表面活性明显增加 ,γmin由 7.9± 0 .9降至 2 .6± 1.2。结论　用萃取和透析的方法能较好地提纯肺表面活性物质蛋白A ,且能较好地保持其生物活性。     

成年猪胰岛的分离与纯化

目的　研究成年猪胰岛的分离与纯化方法。方法　胰岛的分离采用导管内连续灌注胶原酶消化法 ,纯化采用Nycodenz连续密度梯度离心。 结果　消化后每个胰腺平均可获得 (3970 0 0±185 96 3)个胰岛或 (986 0± 3 0 43)个胰岛 /克胰腺组织 ,纯化后为 (1480 0 0± 890 0 0 )个胰岛 /胰腺或(3 75 0± 493)个胰岛 /克胰腺组织 ,纯度 >95 %。体外培养示胰岛对糖刺激反应良好 ;免疫组织化学检查证实胰岛细胞存活。结论　经本法获得的胰岛具有较高的纯度及良好的功能 ,可为临床提供可靠的移植物来源。     

猪胆总管脱细胞基质构建组织工程胆管的生物力学评价

目的　用不同的脱细胞方法对猪胆总管进行处理,比较脱细胞前后的生物力学变化,筛选适宜的脱细胞方法,为组织工程胆管支架材料的应用提供理论依据。 方法　30例猪胆总管,随机分为5组,A组：对照组, B组：0.05 % 胰蛋白酶+核酸酶,C组：0.1 % SDS+核酸酶,D组：1.0 % Triton X-100+核酸酶,E组：1.0 % Triton X-100+0.1 % SDS +核酸酶。在Test Resources生物力学试验机上进行加载一卸载试验和极限抗张强度试验。计算出生物力学材料常数（α1、β1、α2、β2）、弹性模量、极限抗张强度和断裂伸长率等指标。 结果　Ｄ组、Ｅ组的生物力学材料常数（α1、β1、α2、β2）与A组的差异无统计学意义（F = 12.21, P = 0.06）,Ｂ组、C组比A组、D组和Ｅ组的小（P < 0.01）;Ｄ组、Ｅ组的弹性模量比A组的稍增大,但差异不明显（P > 0.05）,Ｂ组、C组比A组的小（P < 0.05）;Ｄ组、Ｅ组的UTS值和SOF值与A组差异不明显（P > 0.05）;B组、C组的UTS值明显小于A组（P < 0.05）,SOF值明显大于A组（P < 0.05）。 结论 应用1.0 % Triton X-100+核酸酶和1.0 % Triton X-100+0.1 % SDS +核酸酶的脱细胞效果好,且不会影响猪胆总管的生物力学特性,是一种比较理想的猪胆总管脱细胞方法。     

The omentum is a site of stromal cell-derived factor 1α production and reservoir for CXC chemokine receptor 4-positive cell recruitment

Background

The mechanism of the omental response to injury remains poorly defined. This study investigates the omental reaction to a foreign body, examining the role of a chemokine ligand/receptor pair known to play a crucial role in angiogenesis and wound healing.

Methods

A ventral hernia, surgically created in the abdominal wall of 6 swine, was repaired with silicone sheeting to activate the omentum. Omental thickness was determined by ultrasonography. Serial stromal cell-derived factor 1α (SDF-1α) concentrations were measured in blood, wound, and peritoneal fluids by enzyme-linked immunosorbent assay.

Results

During the 14-day study period, serial ultrasonography showed a 20-fold increase in omental thickness, and enzyme-linked immunosorbent assay revealed a 4-fold increase in SDF-1α concentration in local wound fluid. Omental vessel count and vascular surface area were 8- to 10-fold higher in reactive omentum. Immunohistochemistry showed nearly complete replacement of control omental fat with CXC chemokine receptor 4 (CXCR4)-positive cells by day 14.

Conclusions

Activated omentum, important in the SDF-1α/CXCR4 axis, may serve as an intraperitoneal reservoir for recruitment of circulating bone marrow-derived cells vital to healing.