下肢静脉高压症顺行性静脉造影的诊断意义

本文对临床上有下肢静脉高压症的56例病人,共76条下肢,进行了顺行性静脉造影的X线研究。其中对12条下肢做了经皮腘静脉造影检查。作者认为:(1)下肢静脉高压除因下肢静脉血栓形成外,下肢深静脉瓣膜功能不全是其另一个主要原因。(2)经皮腘静脉造影是检测下肢深静脉瓣膜功能的有效、准确的方法。(3)下肢静脉造影的联合应用,在检查下肢静脉高压中具有科学性和准确性。     

Studies in stress-relaxation and distensibility characteristics of small skin veins in vivo by a combined photoelectric-photographic and plethysmographic technique

Summary The phenomena of stress-relaxation and capillary outward filtration were studied in the isolated rabbit ear, perfused with blood at constant flow. The volume increase, as measured by the plethysmograph, following elevation of venous outflow pressure to 20 mm Hg for 4 min was predominantly due to capillary outward filtration in the norepinephrine constricted vascular bed (0.5 g/min). With papaverine induced dilatation (0.08 mg/min) this persistent volume increase could be attributed mainly to stress-relaxation of the veins. Engorgement of venous vessels as well as capillary outward filtration led to an increase of the ear volume that is measured by the plethysmographic technique. The photographic-photoelectric measurement of venous diameter changes was used in these experiments to distinguish intravascular from extravascular volume changes. The moduli of volume elasticity were calculated for smaller and larger veins (mean diameter 0.133 mm and 0.553 mm) with norepinephrine constriction. It has been demonstrated that the smaller veins were about seven times less distensible than the larger veins.This investigation was supported by Contract F44620-71-C-0117 of the USAF School of Aerospace Medicine, European Office of Aerospace Research (OAR), U.S. Air Force and Deutsche Forschungsgemeinschaft.This work was presented in part at the 39. Tagung der Deutschen Physiologischen Gesellschaft, Erlangen, April 1972 [Pflügers Arch. Suppl.332, R 54 (1972)].     

Modulation of hemostatic balance with antithrombin III replacement therapy in a case of liver cirrhosis associated with recurrent venous thrombosis

Patients with liver failure can present both thrombotic and hemorragic complications because of the deficiency in coagulation factors and inhibitors (protein C and S, antithrombin III) and impairment of fibrinolytic balance. Here we report the case of a 63-year-old man with liver cirrhosis, recurrent thrombosis, and features of low-grade consumption coagulopathy, showing severe antithrombin III deficiency (about 30% of normal values). Treatment with antithrombin III (2000 U/day) and low doses of heparin (5000 U b.i.d.) was successful in modulating the coagulation system toward an antithrombotic effect. After discharge from hospital the ambulatory treatment with antithrombin III concentrates (2000 U twice a week) allowed the attainment of antithrombin III activity of about 60% and prevented the patient from recurrence of venous thrombosis.Abbreviations AT-III Antithrombin III - DIC Disseminated intravascular coagulation - TAT complexes Thrombin-antithrombin III complexes - PAI-1 Plasminogen activator inhibitor-1     

Interpretation of venous occlusion plethysmography using a nonlinear model

Venous occlusion plethysmography (VOP) is a noninvasive technique widely employed for the detection of deep-vein thrombosis. Previous reports that VOP outflow curves are closely fit by a first-order exponential suggest that venous compliance and resistance are nearly constant. Typically, however, the venous compliance function has a sigmoid shape; in addition, the resistance in a collapsing tube must increase. This paradox was resolved by the surprising finding that for realistic nonlinear compliance and resistance these nonlinearities cancel, producing a quasilinear venous outflow that approximates a simple exponential.     

人TFPI基因转染对兔移植静脉血栓形成和近期通畅率的影响

目的： 为减少冠状动脉旁路移植术后血栓形成，探讨人组织因子途径抑制因子(TFPI)基因转染对兔移植静脉血栓生成的影响。方法：构建真核表达质粒pCMV-(Kozak)TFPI。采用阳离子脂质体和腔内加压灌注法，转染移植静脉内皮细胞。RT-PCR、Western blotting和免疫组化法检测外源基因在兔移植静脉中的表达。病理标本、扫描电镜观察移植静脉血栓形成情况，血管多普勒观测其通畅率。结果：移植静脉中有人TFPI基因和蛋白表达。静脉移植术后3 d，基因转染组、空载体和空白对照组分别有1条、8条和7条移植静脉发生血栓，术后30 d，以上各组分别有0条、5条和5条移植静脉完全闭塞，前者静脉血栓发生率和闭塞率均低于后两者(P<0.05)。扫描电镜显示两对照组内皮表面有红细胞和血小板黏附、聚集，而转染组基本正常。结论：人TFPI基因干预，减少了兔移植静脉血栓形成，提高了近期通畅率。     

Effect of lower-body positive pressure on postural fluid shifts in men

Summary To quantify the effect of 60 mm Hg lower-body positive pressure (LBPP) on orthostatic blood-volume shifts, the mass densities (±0.1 g· l^–1) of antecubital venous blood and plasma were measured in five men (27–42 years) during combined tilt table/antigravity suit inflation and deflation experiments. The densities of erythrocytes, whole-body blood, and of the shifted fluid were computed and the magnitude of fluid and protein shifts were calculated during head-up tilt (60°) with and without application of LBPP. During 30-min head-up tilt with LBPP, blood density (BD) and plasma density (PD) increased by 1.6±0.3 g · l^–1, and by 0.8±0.2 g · l^–1 (±SD) (N=9), respectively. In the subsequent period of tilt without LBPP, BD and PD increased further to +3.6±0.9 g · l^–1, and to +2.0±0.7 g · l^–1 (N=7) compared to supine control. The density increases in both periods were significant (p<0.05). Erythrocyte density remained unaltered with changes in body position and pressure suit inflation/deflation. Calculated shifted-fluid densities (FD) during tilt with LBPP (1006.0±1.1 g · l^–1,N=9), and for subsequent tilt after deflation (1002.8±4.1 g · l^–1,N=7) were different from each other (p<0.03). The plasma volume decreased by 6.0±1.2% in the tilt-LBPP period, and by an additional 6.4±2.7% of the supine control level in the subsequent postdeflation tilt period. The corresponding blood volume changes were 3.7±0.7% (p<0.01), and 3.5±2.1% (p<0.05), respectively. Thus, about half of the postural hemoconcentration occurring during passive head-up tilt was prevented by application of 60 mm Hg LBPP.H. Hinghofer-Szalkay was a European Space Agency fellow on leave from the Physiological Institute, Karl-Franzens-University, A-8010 Graz, Austria.     

颅脑肿瘤术后并发静脉血栓栓塞症危险因素的Meta分析

目的明确颅脑肿瘤术后患者发生静脉血栓栓塞症(VTE)的危险因素。方法检索中国知网、万方、维普、中国生物医学文献、PubMed、The Cochrane Library、Web of Science、EMbase等数据库建库至2021年11月1日颅脑肿瘤术VTE危险因素的队列研究或病例对照研究。由两名研究人员独立进行文献筛选、资料提取以及文献质量评价。使用RevMan 5.4软件对纳入文献进行Meta分析。结果共纳入14篇文献,合计样本量40 552例,发生VTE1 801例。Meta分析结果显示,年龄＞45岁、术前D-二聚体升高、肥胖、女性、术前日常生活活动能力处于依赖状态、术前呼吸机依赖、术前曾患脓毒血症、高级神经胶质瘤、手术时间＞3.05 h、术后D-二聚体升高、术后下肢运动功能障碍、术后卧床不起、术后并发尿路感染为颅脑肿瘤术后患者发生VTE的危险因素。结论颅脑肿瘤术后VTE发生与多种因素有关。建议构建颅脑肿瘤术后VTE风险预测模型,关注高风险人群,落实规范化静脉血栓风险评估,注重血栓评估过程管控。     

恶性肿瘤合并静脉血栓栓塞症患者危险因素分析

目的：分析恶性肿瘤合并静脉血栓栓塞症（VTE）患者的危险因素。方法：选取2020年1月至2022年1月陆军第73集团军医院进行治疗的133例恶性肿瘤患者,对患者一般资料进行回顾性分析,比较恶性肿瘤组患者及恶性肿瘤合并VTE组患者一般资料,通过多因素logistic回归分析明确恶性肿瘤合并VTE的危险因素,比较两组患者1年死亡率。结果：两组患者肿瘤分期、冠心病、化疗、合并感染、激素治疗、中心静脉置管构成比及纤维蛋白原（FIB）、D–二聚体（D–D）、活化部分凝血活酶时间（APTT）、血管性血友病因子（vWF）水平比较,差异具有统计学意义（P <0.05）;多因素logistic回归分析结果表明肿瘤分期Ⅲ～Ⅳ期、有冠心病、有化疗、有感染、有激素治疗及有中心静脉置管、血浆D–D水平高为恶性肿瘤合并VTE危险因素,差异具有统计学意义（P <0.05）。多因素logistic回归分析结果表明,肿瘤分期Ⅲ～Ⅳ期、有冠心病、有化疗、有感染、有激素治疗及有中心静脉置管、血浆D–D水平高为恶性肿瘤合并VTE危险因素（P <0.05）;恶性肿瘤合并VTE组患者1年死亡率明显高于恶性肿瘤组...     

Prediction of hepatic graft viability before reperfusion: an analysis of effluent from porcine allografts

Rapid and reliable assessment of hepatic graft viability is important for successful orthotopic liver transplantation (OLTx). OLTx was performed in 11 pairs of pigs via a venovenous bypass. Six of these grafts were transplanted immediately (group A), while the other five were preserved in University of Wisconsin (UW) solution for 24 h and then transplanted (group B). All grafts were flushed with 300 ml of chilled (4°C) Ringer's lactate solution before reperfusion of the graft, when 20 ml of effluent from the graft was collected and the concentrations of ammonia, lactic acid, GOT, and LDH were measured. Four of the six pigs in group A survived longer than 3 days, while the other two pigs died of causes other than graft dysfunction. All five pigs in group B died either of hemoperitoneum or hemodynamic instability due to liver failure. The histology of postperfusion biopsies in group A showed minimal pathological changes, while the grafts in group B revealed moderate to severe ischemic injuries. Ammonia and lactic acid in the effluent of group B were significantly higher than those of group A (1511±216 vs 417±333 g/dl and 114.1±12.2 vs 91.4±12.2 mg/dl, respectively; P<0.05 in both cases). Before reperfusion, the rate of total adenine nucleotides in all of the substances in the graft, which were measured using high performance liquid chromatography (HPLC), inversely correlated with the ammonia levels in the effluent. We conclude that an analysis of the effluent, (i.e. the levels of ammonia and lactic acid), flushed from a hepatic graft before reperfusion could serve as a predictor of hepatic graft viability.