门静脉高压症猪肺血管的结构重建及临床意义

目的:探讨门静脉高压症猪肺血管形态结构重建的特点。方法:采用健康2月龄湖北白猪14头,随机分为正常对照组和实验组,用四氯化碳建立门静脉高压症模型。取肺动脉和肺静脉,横断切片。用Pilloridine和Cy3-IgG分别染胶原纤维和平滑肌,弹性纤维自发荧光。在激光共聚焦显微镜下观察,用计算机图像分析系统测量各结构成分的相对含量。结果:与正常对照组相比,门静脉高压猪肺血管壁中胶原纤维、平滑肌的相对含量及胶原纤维与弹性纤维的比值(C/E)均增大,弹性纤维则减少。结论:门静脉高压时,猪肺血管的形态结构可发生重建,表现为胶原纤维增加,弹性纤维减少,导致C/E值的改变。肝肺联合移植时,移植材料间的结构成分的差异也应引起关注。     

门静脉高压症猪肝动脉的结构重建

目的 建立猪门静脉高压症模型,探讨门静脉高压症时肝动脉的结构重建.方法猪以四氯化碳、苯巴比妥、乙醇配合高脂、低蛋白、低胆碱饮食进行混合饲养.通过脾静脉插管测压,取肝动脉常规石蜡包埋、切片,用HE 法、Weigert 法、Aniline blue法,Organge 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...     

门静脉高压症猪门静脉的生物力学特性及其临床意义

目的:建立猪门静脉高压症模型,探讨门静脉高压症时门静脉的生物力学特性。方法:采用2月龄湖北白种猪,用四氯化碳、苯巴比妥、乙醇,配合高脂、低蛋白、低胆碱饮食进行混合饲养。通过脾静脉插管测压,取门静脉在生物软组织力学试验机上测定其压力-直径关系,横断取材,冰冻切片,H E法染色,用计算机图像分析系统测量其几何形态学指标。结果:实验组门静脉压为(4.17±1.03)kPa,对照组为(1.51±0.79)kPa(P<0.01),实验组门静脉的Einc、Ep和EV均随压力的上升而增大,在相同压力下明显大于对照组的Einc、Ep和EV。在0～4 kPa压力范围内实验组门静脉的顺应性(C)显著低于对照组,而在4～8 kPa的高压时两者顺应性差异并不明显(P>0.05)。结论:门静脉高压症时,门静脉的生物力学特性均发生了明显变化。肝移植时,移植材料间的生物力学特性也应考虑。     

门静脉高压症猪肝动脉的生物力学特性

目的：建立猪门静脉高压症模型,探讨门静脉高压症对肝动脉的生物力学特性的影响。方法：猪以四氯化碳、苯巴比妥、乙醇,配合高脂、低蛋白、低胆碱饮食进行混合饲养。通过脾静脉插管测压,取肝动脉在生物软组织力学试验机上测定其压力-直径关系,计算机图像分析测量肝动脉两端血管环的张开角及其几何形态学指标。结果：实验组门静脉压(4．17±1．03)kPa明显大于对照组(1．51±0．79)kPa,肝动脉的各向同性增量弹性模量、血管容积弹性模量和血管压力-应变模量均随压力的上升而增大,在相同压力下明显大于对照组。肝动脉的顺应性显著低于对照组,而张开角显著增加。结论：门静脉高压症时,肝动脉的生物力学特性发生了显著变化。     

人与猪肝门静脉显微结构成分的比较

目的：比较人与猪肝门静脉壁结构成分的异同，为猪一人异种肝移植提供理论依据。方法：取正常成人与不同月龄猪肝门静脉，常规石蜡包埋、切片，分染弹性纤维、胶原纤维和平滑肌，光镜观察，计算机图像分析系统测量各结构成分的相对含量。结果：随月龄的增长猪肝门静脉胶原纤维的含量逐渐升高，弹性纤维的含量相对稳定，平滑肌的含量在3月龄时最高，C厄值逐渐升高。与人相比，猪肝门静脉壁中胶原纤维和弹性纤维的含量较低，而平滑肌的含量则较高，5、6月龄时的C/E值与人相近。结论：人与猪肝门静脉壁各结构成分的含量存在差异，但从C僵值看，5、6月龄猪肝门静脉的力学特性与人相匹配，较适合用于移植。     

门静脉高压症血液动力学研究

在接受门奇断流手术的门静脉高压症患者中 ,我们测量了自由门静脉压力 (FPP)、脏侧闭塞门静脉压力 (SOPP)、平均动脉压力 (Pa)和肝外门体分流率 (PSS)。其结果是 :断流术后FPP下降 0 .4 9± 0 .6 9(SD)kPa(P <0 .0 0 5) ,从术前的 3.86± 0 .70kPa降至 3.37± 0 .93kPa ;SOPP增加了 1.0 3± 1.0 3kPaP <0 .0 0 0 5) ,从术前的 5.4 9± 1.0 6kPa增至 6 .52± 1.4 5kPa ;Pa仅增加 0 .2 7± 1.80kPa ,无统计学意义 (P >0 .2 5) ;PSS减少了 2 5.1± 13.5%(P <0 .0 0 0 5) ,从术前的 57.6± 15.2 %降至32 .5± 16 .1%,表明门奇断流术阻断了这部分经门体交通支分流的血流量 ,使其转向肝脏 ,有利于术后肝脏功能的维护。     

血吸虫病性门静脉高压症兔肝脏微血管构筑变化的研究

目的:探讨血吸虫病门静脉高压症时肝脏微血管构筑的变化及其可能在全身高动力循环状态中的作用。方法:采用腹部敷贴法感染血吸虫尾蚴建立血吸虫病性肝纤维化模型,经插管检测心输出量(CO)、平均动脉压(MAP)、心率(HR)和肝静脉嵌塞压(WHVP),按公式计算心脏指数(CI)、外周血管阻力(SVR);通过血管铸型方法观察肝脏微血管构筑。结果:与正常兔比较,血吸虫病兔CO、CI明显增高,MAP和SVR显著降低,WHVP升高,两组间HR差异无统计学意义。肝脏微血管铸型观察,血吸虫病时肝内微血管形态和比例严重失常,肝窦显著膨大,门静脉主干增粗,肝内形成广泛的小吻合支,其间以门静脉终末支与肝静脉终末支、门静脉小分支直接引流入肝静脉多见。结论:血吸虫病性门静脉高压症兔存在肝内门-体分流病理改变,可能是形成全身高动力循环状态并维持门静脉高压的一个重要环节。     

猪肝门静脉壁组织结构增龄性变化的定量分析

目的　探讨猪肝门静脉壁结构成分的增龄性变化 ,为猪 -人异种肝移植提供理论依据。方法　取正常不同月龄猪肝门静脉 ,HE染色 ,Weigert、Anilineblue及桔黄G分染弹性纤维、胶原纤维和平滑肌 ,光镜观察 ,计算机图像分析系统测量各结构成分的相对含量。结果　猪肝门静脉随月龄的增长胶原纤维的含量逐渐升高 ,弹性纤维的含量相对稳定 ,平滑肌的含量在 3月龄时最高 ,胶原纤维与弹性纤维含量的比值 (C/E)逐渐升高。结论　猪肝门静脉壁各结构成分的相对含量随增龄发生变化 ,在实施猪 -人异种肝移植时应选择与人肝门静脉壁结构成分含量相近的月龄猪作为供体。     

肝前性门静脉高压症的诊断和治疗

目的 :探讨肝前性门静脉高压症的临床特点、诊断和治疗方法的选择。方法 :经造影和手术发现非肝硬化性门静脉纤维化 3例 ,肝外门静脉阻塞 9例 ,临床表现除具有与肝硬化门静脉高压症相似表现外 ,尚具有年龄轻 ,肝功能化验正常等特点。治疗采用门静脉隔膜切除 1例 ,自体血管搭桥 1例 ,肠腔分流 3例 ,脾切除、脾肾分流 7例。结果 :1例死亡 ,11例治愈 ,随访 6月～ 70个月 ,再次出血 1例。结论 :肝前性门静脉高压症与其他类型的门静脉高压症在临床表现方面有许多不同之处。分流手术可作为基本手术     

肝门静脉左支的临床解剖学

目的:观测肝门静脉左支的形态特征和分支分布规律,为诊断和治疗肝疾病提供更为详尽的形态学资料.方法: 50例肉眼观察无病变的成人尸体肝并进行剥离解剖,对肝门静脉左支的形态结构进行观察,测量其主干及主要分支的相关数据并进行统计学分析.结果: 左支横部、矢部长分别为(23.90±5.29)mm, (24.02±4.97)mm;内径分别为(7.43±1.09)mm, (7.07±1.36)mm;角部角度为114.18°±22.59°.左外叶上段支长(48.57±17.51)mm,其根部、1/2处、末端的内径分别为(3.72±1.16)mm, (3.08±0.91)mm, (2.53±0.77)mm.左外叶下段支长(39.42±14.57)mm,其根部、1/2处、末端的内径分别为(3.98±1.05)mm, (3.40±0.98)mm, (2.87±1.11)mm.20.0%的左支矢状部被肝实质覆盖,平均范围为(25.0±11.89)mm,厚度为(19.3±5.96)mm.结论:肝门静脉左支主干的径值和角度变动范围较大,除分支供应左半肝外,尚可发出右前叶支至右前叶;固有尾状叶的血供主要来自肝门静脉左支主干,其分支分布直接影响到左半肝分叶分段,具体定界应结合实际情况而定.     

Microvasculature in the small portal tracts in idiopathic portal hypertension

Summary The morphology of the microvasculature in the small portal tracts was examined in normal livers, idiopathic portal hypertension (IPH) and other hepatic diseases. The microvasculature examined was arbitrary divided into two groups: that near the limiting plate and that within portal tracts, particularly around bile ducts. Based on comparisons of histology, immunohistochemistry and vascular casts, it is suggested that the former corresponded to inlet venules and the latter to distributing portal veins and peribiliary capillary plexus. Both of these microvasculatures were positive forUlex europaeus lectin I, and (infrequently and weakly) for factor VIII-related antigen. Morphometry disclosed that inlet venules were reduced in number in IPH compared with normal livers and that distributing portal veins, peribiliary capillary plexus and inlet venules were increased in extrahepatic portal obstruction, chronic active hepatitis and extrahepatic obstructive cholestasis. We believe that the change in the microvasculature reflects abnormal microcirculation in the small portal tracts, and that the reduction of inlet venules plays an important role in the development of portal hypertension in IPH.     

HLA-DR expression on the microvasculature of portal tracts in idiopathic portal hypertension. Immunohistochemical characteristics and relation to portal phlebosclerosis

We recently reported that HLA-DR antigen was expressed on the microvasculature of portal tracts more frequently in idiopathic portal hypertension (IPH) than in normal livers or in other hepatic diseases, and that this HLA-DR expression may be involved in the development of the portal venopathy characteristic of IPH. The present study was performed to evaluate the relationship between the HLA-DR expression and portal tract lesions, as well as to investigate the immunohistochemical characteristics of the HLA-DR-positive microvasculature using liver wedge biopsy specimens obtained from 32 patients with IPH. According to the degree of phlebosclerosis of the portal veins, the portal tracts were divided into three groups: mild, moderate, and severe. The microvasculature in portal tracts was positive for HLA-DR in 21 (66%) of the 32 specimens and in 133 (44%) of 302 portal tracts. In the 21 specimens, there was no significant difference in the prevalence of HLA-DR-positive microvasculature among the three groups: it occurred in 57 (66%) of 86 portal tracts in the mild group, 53 (61%) of 87 portal tracts in the moderate group, and 23 (49%) of 47 portal tracts in the severe group. The HLA-DR-positive microvasculature was positive for type IV collagen and receptors of Ulex europaeus lectin I, suggesting that HLA-DR-positive microvessels are blood vessels. These findings suggest that HLA-DR antigen is already expressed on portal microvessels in the incipient stage of IPH, and that HLA-DR expression persists during the progression of portal phlebosclerosis. The HLA-DR expression may be an initiating factor leading to immunologic assault on portal microvessels in IPH.     

Metoprolol in portal hypertension

Summary In a controlled trial, the effect of the ₁-selective blocking agent metoprolol on cirrhotic portal hypertension was investigated. A sustained reduction of portal pressure was observed in 60% of the treated patients after 1 and 2 months. No correlation between changes of portal pressure and cardiac output was established. This may indicate a direct action of-blocking substances on the splanchnic vascular system. The results suggest that treatment with metoprolol may be of value in patients with portal hypertension secondary to cirrhosis of the liver. However, to eliminate nonresponders the pressure has to be measured repeatedly.     

Idiopathic noncirrhotic portal hypertension

Cirrhosis is the most common cause of portal hypertension but there are many causes of noncirrhotic portal hypertension. Many of these etiologies may be diagnosed by liver biopsy. Idiopathic noncirrhotic portal hypertension is being increasingly diagnosed and has varied histopathological findings as well as overlapping definitions. Many of these histological changes can be subtle, thus making it a challenging diagnosis for the pathologist to make. This review summarizes the clinical aspects of idiopathic noncirrhotic portal hypertension and outlines the different definitions and histological features of the entity. In addition, pearls and pitfalls for the pathologist in making this diagnosis are included.     

Blood flow in mesenteric,hepatic portal and renal portal veins of chickens

Blood flows were determined by electromagnetic probes placed upon the posterior vena cava (PVC), coccygeomesenteric vein (COCMV), mesenteric vein (MV), and hepatic portal vein (PV) of white Leghorn males. Blood flow in ml/min of non-fasted, unanesthetized males were as follows: (see article). Withholding food for 24 hrs decreased flow significantly only in the MV and PVC. Anesthesia decreased flow in PVC, PV and COCMV. After ligation of PVC, blood was shunted from caudal areas and renal portal circulation to COCMV and liver. Ligation of PV caused a diversion of flow to renal portal circulation and an increase in PVC flow and a reversal of direction of flow in COCMV.     

Investigation of tilted dose kernels for portal dose prediction in a-Si electronic portal imagers

The effect of beam divergence on dose calculation via Monte Carlo generated dose kernels was investigated in an amorphous silicon electronic portal imaging device (EPID). The flat-panel detector was simulated in EGSnrc with an additional 3.0 cm water buildup. The model included details of the detector's imaging cassette and the front cover upstream of it. To approximate the effect of the EPID's rear housing, a 2.1 cm air gap and 1.0 cm water slab were introduced into the simulation as equivalent backscatter material. Dose kernels were generated with an incident pencil beam of monoenergetic photons of energy 0.1, 2, 6, and 18 MeV. The orientation of the incident pencil beam was varied from 0 degrees to 14 degrees in 2 degrees increments. Dose was scored in the phosphor layer of the detector in both cylindrical (at 0 degrees) and Cartesian (at 0 degrees - 14 micro) geometries. To reduce statistical fluctuations in the Cartesian geometry simulations at large radial distances from the incident pencil beam, the voxels were first averaged bilaterally about the pencil beam and then combined into concentric square rings of voxels. Profiles of the EPID dose kernels displayed increasing asymmetry with increasing angle and energy. A comparison of the superposition (tilted kernels) and convolution (parallel kernels) dose calculation methods via the chi-comparison test (a derivative of the gamma-evaluation) in worst-case-scenario geometries demonstrated an agreement between the two methods within 0.0784 cm (one pixel width) distance-to-agreement and up to a 1.8% dose difference. More clinically typical field sizes and source-to-detector distances were also tested, yielding at most a 1.0% dose difference and the same distance-to-agreement. Therefore, the assumption of parallel dose kernels has less than a 1.8% dosimetric effect in extreme cases and less than a 1.0% dosimetric effect in most clinically relevant situations and should be suitable for most clinical dosimetric applications. The resulting time difference for the parallel kernel assumption versus the tilted kernels was 10.5 s vs 18 h (a factor of approximately 6000), dependent on existing hardware and software details.