人脐静脉组织构筑及其临床应用价值

本研究旨在为脐带静脉作为小口径移植材料的临床应用提供理论依据。采用胎龄在 2 4～ 4 2周脐带静脉 5 0例 ,常规石蜡包埋、切片。用HE法、Weigert法、苯胺蓝法及桔黄G法分别染组织结构、弹性纤维 胶原纤维和平滑肌。光镜观察后 ,用计算机图像分析系统测量其中膜显微结构成分的相对含量。随胎龄增加 ,脐带静脉中膜弹性纤维含量逐渐增多 ,胶原纤维含量及C/E值逐渐减少 (P <0 0 1)。近段胶原纤维含量比远段少 (P <0 0 1) ,由近段到远段C/E值逐渐增大。脐带静脉具有与普通中等动脉相似的结构 ,作为小口径动脉移植的替代材料是可行的 ,建议选用胎龄在 37～ 4 0周之间的脐带静脉作为临床应用的移植材料。同时应注意选择不同段脐带静脉 ,使移植材料与宿主血管间的组织构筑尽可能相近 ,以提高移植血管的远期通畅率。     

不同段脐带静脉组织结构的定量分析及其临床意义

目的：对不同段脐带静脉的几何形态和显微结构成分的比较，为脐带静脉移植的临床应用提供形态学依据。方法：采用自然分娩正常胎儿脐带静脉20例，常规石蜡包埋、切片。用HE法、weigert法、苯胺蓝法及桔黄G法分别染组织结构、弹性纤维胶原纤维和平滑肌。用计算机图像分析系统测量脐带静脉的几何形态及显微结构成分的含量。结果：从近段到远段，脐带静脉中膜厚度及外径值逐渐减小。胶原纤维的相对含量近段比远段少，由近段到远段C／E值逐渐增大。结论：脐带静脉可作为小口径动脉移植的替代材料。但移植时，应注意选择不同段脐带静脉，使之与宿主血管匹配。     

胎儿脐带静脉的蠕变特性

为脐带静脉作为小口径移植材料的临床应用提供蠕变特性指标。对产妇年龄在22～28岁,胎龄37～40周自然分娩正常胎儿脐带静脉近胎盘段和远胎盘段各10个试样在日本岛津电子万能试验机上进行蠕变实验,模拟人体温在36.5±0.5℃的温度场下以0.01 Mpa/s的应力增加速度对试样施加应力,设定时间为7 200 s。采集100个数据,采用归一化分析的方法计算两组试样的归一化蠕变方程。两组试样蠕变曲线是以指数关系变化的,胎儿脐带静脉近胎盘段和远胎盘段7 200 s蠕变量差异显著(P<0.05)。胎儿脐带静脉近胎盘段和远胎盘段具有不同的蠕变特性。     

胎儿脐带静脉的生物力学特性研究

探讨胎儿脐带静脉随胎龄变化的生物力学特性的改变,为临床挑选适当的血管代用品提供理论依据。方法：33例新鲜脐带静脉,用生物软组织力学试验机测定血管的压力、容积、外径等力学参数,计算出弹性模量、顺应性。结果：37－40周时脐静脉的P－V曲线比较高,弹性模量与血压的关系曲线较低,此时段顺应性最好。结论：建议选用胎龄在37－40 周之间的脐静脉作为移植材料。     

猪肝动脉的弹性模量与性别的关系

目的探讨猪肝动脉弹性模量与性别的关系,为猪到人异种肝移植提供理论依据。方法取23例4、7月龄雌性、雄性、去势湖北白猪的肝动脉,将其按从近心端到远心端的方向分成近、中、远3段,各段置于4℃冰箱中待用。在软组织生物力学试验机上测定中段动脉的压力-直径关系,计算出增量弹性模量(Einc)、压力-应变弹性模量(Ep)和容积弹性模量(Ev)。结果 7月龄各组肝动脉的弹性模量有显著性差异(P0.01):雌性组最低,雄性组居中,去势组最高;7月龄各组与4月龄各组的弹性模量相比显著减小(P0.05)。结论 7月龄不同性别猪肝动脉弹性模量存在差异,从生物力学方面考虑,在猪到人异种肝移植时,应选择性别相匹配的猪肝脏作为供体材料,使移植材料肝动脉间的弹性模量尽可能相近,降低肝动脉并发症,有可能提高移植肝的存活率。     

胎儿脐静脉壁组织结构增龄性变化的定量分析

目的 :探讨胎儿脐带静脉随胎龄变化的形态学改变 ,为临床挑选适当的血管代用品提供科学的理论依据。方法 :3 3例新鲜脐带 ,常规石蜡包埋、切片、HE染组织结构 ,Weigert,AnilineBlue及桔黄G分染弹性纤维 ,胶原纤维和平滑肌 ,光镜观察及计算机图像分析。结果 :随胎龄随长 ,脐静脉管径、中膜厚度、中膜弹性纤维含量逐渐增多 ;平滑肌含量及细胞核的数密度和面密度在 3 7～ 40周最大 (P <0 .0 5 ) ,胶原纤维则最小 ,因而此时段顺应性最好。结论 :脐静脉管壁中各成分的含量随胎龄变化呈不等比增长 ,3 7～ 40周时血管顺应性最好。建议选用此时段胎龄的脐静脉作为移植材料。     

不同胎龄脐带静脉顺应性的变化及其临床意义

目的：为脐带静脉的临床应用从生物力学性质上提供理论依据。方法：采用胎龄以24－42周流产及自然分娩正常胎儿脐带静脉50例，测定其压力－容积关系。结果：脐带静脉的p-V曲线可用抛物线拟合。脐带静脉顺应性随胎龄增加而增大，但39周以后又降低。结论：人脐带静脉是动脉移植物的良好替代材料，在移植时除了考虑脐带静脉与宿主动脉相匹配外，还应注意其顺应性与胎龄的关系，建议选用胎龄在37－40周之间的脐带静脉作为临床应用的移植材料。     

胎儿静脉壁组织结构增龄性变化的定量分析

目的：探讨胎儿脐带静脉随胎龄变化的形态学改变，为临床挑选适当的血管代用品提供科学的理论依据。方法：33例新鲜脐带，常规石蜡包埋、切片、HE染组织结构，Weigert,Aniline Blue及桔黄G分染弹性纤维，胶原纤维和平滑肌，光镜观察及计算机图像分析。结果：随胎龄随长，脐静脉管径、中膜厚度、中膜弹性纤维含量逐渐增多；平滑肌含量及细胞核的数密度和面密度在37－40周最大（P＜0．05），胶原纤维则最小，因而此时段顺应性最好。结论：脐静脉管壁中各成分的含量随胎龄变化呈不等比增长，37－40周时血管顺应性最好。建议选用此时段胎龄的脐静脉作为移植材料。     

门静脉高压症猪肺血管的生物力学特性

目的：探讨门静脉高压症猪肺血管的生物力学特性及为临床晚期肝硬化患者实施肝肺联合移植提供理论依据。方法：采用健康2月龄湖北白种猪4头作为正常对照组，四氯化碳诱导的门静脉高压组湖北白种猪10头，分别取其肺动脉、肺叶动脉、肺段动脉及肺静脉，在软组织生物力学试验机上测定压力一直径关系数据，推导出其弹性模量和顺应性。结果：与正常对照组相比，门静脉高压组（PHT）猪肺动静脉血管的弹性模量随血管内压力的升高而增大；顺应性则随血管内压力的增大而下降。结论：与人类相似，PHT猪可伴有肺血管生物力学特性的改变，且生物力学特性变化的幅度可能与病情变化有关。肝肺联合移植时，移植材料间的生物力学特性也应引起关注。     

狗冠状动脉的生物力学特性：Ⅰ.一维载荷下力学特性的实验研究

本文报道采用6例狗的左冠状动脉前室间支、旋支,右冠状动脉、胸廓内动脉,大隐静脉以及股静脉在生物软组织力学试验台上,进行离体的压力-直径关系和一维载荷下的应力-应变关系实验。上述血管的各向同性增量弹性模量(E_(inc)、容积弹性模量(E_v)和压力-应变模量(E_p)随血管内压力(P)的上升而增大;这些血管的dT/dλ随张应力T的增加而增大,其一维载荷下的应力-应变关系为指数函数。讨论了上述血管的显微结构成份含量与力学特性的关系,以及冠状动脉旁路移植实验研究中的力学问题,认为动脉的C/E值可以反映动脉弹性的大小;胸廓内动脉的力学特性比静脉更接近于冠状动脉,冠状动脉旁路移植时可优先选用该动脉。     

Biomechanical properties of different segments of human umbilical cord vein and its value for clinical application

No satisfactory effects have been obtained with the use of synthetic blood vessels (diameter <6 mm) as substitutes for human small arteries or veins for the purpose of clinical vascular reconstruction. Therefore, blood vessels of human origin, for example, umbilical cord blood vessels, with their wide availability, still should be considered. However, little information on biomechanical properties of human umbilical cord blood vessels is available. The objective was to provide a theoretical basis for the clinical application of umbilical cord veins as optional material for small-caliber grafts. This was a nonrandomized, noncontrolled in vitro study. The experiment was conducted in the Laboratory of Medical Biomechanics, Yunyang Medical College. Umbilical cord veins of 20 normal fetuses of spontaneous labor were collected by the Department of Obstetrics and Gynecology, Taihe Hospital in Shiyan City, Hubei Province. The fetuses aged 37-40 weeks, and the parturients were 20-30 years old. Umbilical cord veins of the 20 fetuses were used and the placental ends were treated as proximal ends while the fetal ends as distal ends. The fetal ends were divided into three segments: proximal, middle, and distal segments. The relationship between pressure of umbilical cord veins segments and the diameters was measured on the biomechanical experiment stand for soft tissues, and then the elastic modulus was calculated. The materials were transversely extracted, refrigerated, and sliced up before HE staining. The geometrical morphology indexes were measured by a computer image analysis system (Leica-Q500IW). The main outcome measures were: incremental elastic modulus (E(inc)), pressure-strain elastic modulus (E(p)), volume elastic modulus (E(v)), diameter, and wall thickness of the veins. E(inc), E(p), and E(v) of umbilical cord veins of proximal, middle, and distal segments increased with the pressure elevated. The three kinds of elastic modulus of proximal segments (E(inc): 26.98 +/- 3.21, E(p): 16.58 +/- 2.12, E(v): 8.31 +/- 2.35) were all lower than those of distal segments (E(inc): 33.20 +/- 4.21, E(p): 119.45 +/- 2.87, E(v): 9.71 +/- 1.32) (F = 95.74-126.52, p < 0.05), and a tendency to increase was shown from proximal segments to distal segments. Media thickness [(0.30 +/- 0.05)] mm, (0.24 +/- 0.03) mm] and the diameters [(3.07 +/- 0.12) mm, (2.30 +/- 0.13) mm] decreased gradually from proximal to distal segments (F = 12.76, p < 0.01). It is feasible to use umbilical cord veins as substitutes for the transplantation of small-caliber arteries in terms of basic biomechanical properties. On vascular grafting, different segments of umbilical cord veins should be chosen cautiously so that the biomechanical characteristics of umbilical cord vein grafts could be in accordance with those of host to increase the long-term patency rate of transplanted blood vessels.     

人脐血间充质干细胞移植改善肝硬化大鼠的肝功能

背景：人脐血间充质干细胞移植治疗肝硬化的可行性及机制有待深入探讨。 目的：观察经门静脉移植人脐血间充质干细胞对肝硬化大鼠肝功能及组织病理学改变的影响。 方法：采用四氯化碳法制备肝硬化大鼠模型,造模成功后,细胞移植组经门静脉注射1 mL BrdU标记的人脐血间充质干细胞(5×106个),模型组注射等体积的PBS;以经门静脉移植1 mL人脐血间充质干细胞的正常大鼠作为对照。细胞移植后4周,取大鼠尾静脉血及肝脏组织进行检测。 结果与结论：细胞移植后4周,与模型组比较,细胞移植组大鼠血清谷丙转氨酶、谷草转氨酶、总胆红素明显降低,而白蛋白明显升高(P < 0.01);肝细胞炎性坏死、脂肪变及肝纤维化程度明显改善(P < 0.05或P < 0.01)。免疫组化及免疫荧光染色显示细胞移植组和对照组大鼠肝组织中均有人脐血间充质干细胞的定植,但细胞移植组BrdU阳性细胞数目明显多于对照组。RT-PCR检测结果显示,细胞移植组大鼠肝组织表达人源性细胞角蛋白18和白蛋白mRNA,而模型组未见。可见人脐血间充质干细胞移植可在一定程度上改善肝硬化大鼠的肝功能及病理损伤,其机制可能与移植细胞在肝硬化大鼠肝内归巢定植并向肝样细胞分化有关。     

人脐血间充质干细胞尾静脉移植治疗扩张型心肌病

背景：体外研究表明人脐血间充质干细胞可分化为自律性跳动的心肌细胞,而经静脉移植人脐血间充质干细胞治疗扩张型心肌病心力衰竭的报道较少。 目的：探讨经尾静脉移植人脐血间充质干细胞对扩张型心肌病大鼠心肌结构、心功能的影响。 方法：Wistar大鼠通过腹腔注射阿霉素诱导扩张型心肌病模型,扩张型心肌病实验组于造模后8周经尾静脉移植人脐血间充质干细胞,扩张型心肌病对照组注射等量DMEM培养基。健康对照组不造模,于相同时间点注射等体积的生理盐水。 结果与结论：与健康对照组相比,扩张型心肌病组心功能明显受损,且扩张型心肌病实验组受损较扩张型心肌病对照组轻;移植的细胞有肌钙蛋白T的表达。结果提示人脐血间充质干细胞移植能促进扩张型心肌病大鼠心功能恢复,使心肌组织病变减轻。     

Pre-eclampsia associated alterations of the elastic fibre system in umbilical cord vessels

Although pre-eclampsia (PE) is often associated with fetal hypoxia, hypertension and/or disturbed function of the fetal circulation, the effect of these altered hemodynamic parameters on the structure and composition of umbilical vessels has not been systematically investigated before. Therefore, this study focuses on PE-associated changes of the elastic fibre system in umbilical cord vessels investigated by light and electron microscopy, immunocytochemistry and biochemistry. In umbilical cord veins, no changes in thickness of the vessel wall or of any sublayer were observed. However, the internal elastic lamina of the veins was split in 80% of the PE-group in contrast to 20% in uncomplicated pregnancies. This effect was significant (α <0.01) from 36 weeks of gestation onwards. In umbilical cord arteries, the entire arterial vessel wall was found to be 15% thicker in PE than in uncomplicated pregnancies. The enlargement was caused by an increase of both the tunica intima and tunica media. The thickening of the tunica intima was attributed to a migration of smooth muscle cells towards the endothelium, accompanied by a splitting of the internal elastic lamina. Compared to uncomplicated pregnancies, smooth muscle cells of arteries and veins in PE showed a metabolic activation demonstrated by highly dilated endoplasmic reticulum. A semiquantitative score method as well as a quantitative dot blot assay indicated a PE-associated reduction of elastin expression in the arterial vessel walls. In summary, PE obviously induces a decrease of the elastin content accompanied by a thickening of the vessel wall in umbilical cord arteries. This remodeling of the elastic fibre system, together with an increased migration of smooth muscle cells, might represent part of the functional adaptation system of the umbilical cord arteries on the altered hemodynamic conditions in PE. Accepted: 29 November 1999     

The posterior intercostal vein: A thermoregulatory gateway to the internal vertebral venous plexus

The internal vertebral venous plexus (IVVP) plays a putative role in thermoregulation of the spinal cord. Cold cutaneous venous blood may cool, while warm venous blood from muscles and brown fat areas may warm the spinal cord. The regulating mechanisms for both cooling and warming are still unknown. Warm venous blood mainly enters the IVVP via the intervertebral veins. In the thoracic area these veins are connected to the posterior intercostal veins. In this study, anatomical structures were investigated that might support the mechanisms by which warmed venous blood from the intercostal muscles and the recently described paravertebral patches of brown adipose tissue are able to drain into the vertebral venous plexus. Therefore, tissue samples from human cadavers (n = 21) containing the posterior intercostal vein and its connections to the IVVP and the azygos veins were removed and processed for histology. Serial sections revealed that the proximal parts of the posterior intercostal veins contained abundant smooth muscle fibers at their opening into the azygos vein. Furthermore, the walls of the proximal parts of the posterior intercostal veins contain plicae that allow the vessel to dilate, thereby allowing it to serve as a pressure chamber. It is suggested that a cold induced closure of the intercostal/azygos opening can result in retrograde blood flow from the proximal posterior intercostal vein towards the IVVP. This blood flow would be composed of warm blood from the paravertebral brown adipose tissue and blood containing metabolic heat from the muscles draining into the intercostal veins. Clin. Anat. 26:735–740, 2013. © 2013 Wiley Periodicals, Inc.     

不同胎龄人脐血管的生物力学特性及其临床意义

为人脐血管的临床应用从生物力学性质上提供理论依据。采用胎龄在24－42周流产及自然分娩正常胎儿脐动脉和脐静脉50例,测定其压力－容积关系,并求出其顺应性。发现脐动脉和脐静脉的P－V曲线可用抛物线来拟合。获得了脐动脉和脐静脉顺应性随胎龄增加而增大,但39周以后又降低的变化规律。脐静脉顺应性是脐动脉的2－3倍。人脐动脉和脐静脉是动脉移植物的良好替代材料,在移植时除了考虑脐血管与宿主动脉顺应性相匹配外,还应注意其顺应性与胎龄的关系,建议选用胎龄在37－40周之间的脐动脉和脐静脉作为移植材料。