An underlying mechanism for improved liver preservation with a combined histidine-lactobionate-raffinose flush solution

In previous experimental liver transplant studies, it was possible to extend cold ischaemic time (CIT) by using a flush/storage solution combining histidine, lactobionate and raffinose (HLR). In this study, energy metabolism, glycolytic substrate (glucose) and anaerobic end-product (lactate) were examined in rat liver over 24 h of cold storage to determine the mechanism of action of the HLR solution. In livers subjected to simple flush and storage with the HLR solution. levels of ATP and ADP were considerably higher than livers stored with modified UW throughout 24 h of storage; at 4 h of storage, ATP and ADP levels were 1.1 and 3.1 mol/g for HLR solution versus 0.18 and 0.81 mol/g for UW solution. Total adenylate contents (TA=ATP+ADP+AMP) also remained 1–2 mol/g higher in HLR-treated livers than those preserved in UW; TA values ranged from 3.8 to 5.7 mol/g. Glucose increased to 20–35 mol/g by 10–24 h of storage (similar to the UW group). Lactate rose to almost twice that in livers stored in UW; total lactate accumulation was approximately 10.0 mol/g. This study demonstrated that the combined HLR solution is able to prolong the maximum safe CIT by increasing anaerobic metabolism and consequently preserving liver energetics. The second part of the experiment examined the effect of continuous perfusion (with/without O₂) over the 1st h of cold ischaemia. Under current methods of liver flushing and excision, the 1st h of cold storage may be the critical time of metabolic adjustment since most of the pH and ATP changes occur during this period. Therefore, we tested the hypothesis that the combination of a simple flush with an additional brief 1-h perfusion period prior to storage would enhance the maintenance of hepatic energetics. There was no beneficial effect of 1 h of perfusion without O₂ compared to simple HLR flush and storage. However, perfusion with O₂ resulted in prolonged maintenance of high energy adenylates and total adenylates; at 10 h of storage ATP was 1.0, ADP 3.3, and TA 5.7 mol/g. However, any improvement in ultimate viability following long-term storage of the livers in these two groups needs to be tested in an animal transplant model.     

Retransplantation of the liver after side-to-side caval anastomosis

Caval reconstruction in orthotopic liver transplantation is generally performed by two end-to-end anastomoses, using a portal and caval-axillary bypass to sustain hemodynamic stability. In the piggyback modification, the donor's suprahepatic inferior vena cava (IVC) is anastomosed end-to-side to the recipient's preserved IVC. We have used a recently described variant of the piggyback in 18 patients in whom both IVCs are anastomosed side-to-side. We report two patients who needed three retransplants after this reconstruction and conclude that regrafting can be performed in a quick and safe manner.     

Clinical features of hepatic artery thrombosis after pediatric liver transplantation

Thrombosis of the hepatic artery (HAT) is a severe complication of liver transplantation, and most cases need regrafting. The aim of this study was to review our experience with this complication. From January 1986 through January 1992, 76 liver transplants were performed in 59 pediatric patients at the Children's Hospital La Paz, Madrid. The diagnosis of HAT was made in 12 cases (15.7%). The common patterns of clinical presentation were: fulminant liver necrosis (5), bile leak due to necrosis of the bile duct (4), and relapsing bacteremia (3). Clinical symptoms of fulminant liver necrosis started within the first 2 weeks after transplantation, with rapid deterioration and steep rises in SGOT and SGPT levels. All these patients were retransplanted on an urgent basis, but only 1 is alive 4 years later. Four patients developed bile leaks 13 to 60 days after transplantation; SGOT, SGPT, and total bilirubin were only slightly increased. Three children were retransplanted electively and are alive with a mean follow-up of 3 years. One exceptional patient had a Roux-en-Y jejunostomy and is doing well 30 months later with his original graft. The 3 remaining children had episodes of septicemia with hepatic abscess, liver infarction, and pleural effusion. Liver function tests were normal, with bilirubin levels below 2 mg/dl. All patients were retransplanted, but only 1 is alive and well 13 months later. In the present series, we found that early HAT produces fulminant clinical deterioration requiring an urgent regraft. Late HAT presenting with either infection or bile leak allows time for treatment by elective retransplantation. The best survival was obtained in the latter group. Correspondence to: J. Vázquez     

试论当前无偿献血工作的几个关键环节

在宣传贯彻落实《献血法》,开展公民无偿献血工作启动阶段,有许多工作要做,其中有五项是关键性的,即制定具体实施细则,建立管理机构网络,广泛宣传发动,分配献血指标和提供便利的献血条件。抓好这五个关键环节,无偿献血工作才能较好地开展下去。     

B超图像纹理的复杂性分析

本文提出一种复杂性度量法对肝脏Ｂ超图像纹理的分类进行了研究,图像的灰度值复杂性作为纹理特征。     

大鼠肝细胞线粒体三维结构的观察与重建

为深入研究大鼠肝细胞线粒体形态特征,本研究以钻石刀连续超薄切片,通过电子显微观察大鼠肝细胞线粒体的三维结构,对特殊形态的线粒体进行三维结构重组。结果表明：球形,椭球形,盘状及杆状等小型线粒体约占线粒体总数的５３．８％,而分枝形及各种不规则形的线粒体约占４１．６％。     

脑干肿瘤切除术中听诱发电位的监护

脑干是生命中枢所在部位,也是神经中枢的“中枢””’,该部位肿瘤手术风险大,治疗效果差。随着显微外科和影像学等技术的发展,现在脑干肿瘤手术取得很大的进展。如何在尽可能切除脑干肿瘤的同时,及时察觉和避免损伤正常脑干组织,使手术更加安全,除了应用显微外科等...     

Effects of polychlorinated biphenyls on liver ultrastructure, hepatic monooxygenases, and reproductive success in the barbel

Polychlorinated biphenyls (PCBs) are organochlorinated micropollutants ubiquitously distributed in the environment. They are known to be strong inducers of hepatic monooxygenases in fish. This can adversely affect reproduction by increasing steroid metabolism. In this work, adult barbels were contaminated with food containing Aroclor 1260, a commercial PCB mixture from Monsanto, at environmentally relevant concentrations. A significant increase in cytochrome P450 was observed, and two particularly sensitive enzymes, ethoxyresorufin o-deethylase (EROD) and ethoxycoumarin o-deethylase (ECOD), were strongly induced. Electron microscopy revealed alterations in liver ultrastructure in contaminated fish, principally an increase in the number of cisternae of the rough endoplasmic reticulum, drastic glycogen depletion, dissolution of mitochondrial contents, and appearance of myelin figures. Contamination was also studied in relation to reproductive success in a hatchery. Contaminated males displayed no alteration in milt quality, but PCBs did alter female reproductive parameters. Total mortality of eggs and larvae increased significantly with the level of PCBs in the eggs. The most highly contaminated fish did not even spawn. All the adverse effects recorded here tended to be reversible when the intoxication ended, sometimes after only a 1-year detoxication period.     

Ontogeny of serine hydroxymethyltransferase isoenzymes in fetal sheep liver, kidney, and placenta

Serine is an amino acid that is not transported from the placenta to the ovine fetus. Thus, fetal plasma serine levels may be controlled by flux through their relevant biosynthetic pathways. This study was designed to determine, in fetal sheep tissues, the ontogeny of the three key enzymes in the biosynthetic pathway for serine, the cytosolic (c) and mitochondrial (m) isoforms of serine hydroxymethyltransferase (SHMT), phosphoglycerate dehydrogenase (PGD), and phosphoserine aminotransferase (PSAT). PGD and PSAT activity did not vary during gestation in either liver (PSAT, 9.4 +/- 1.3 nmol/min/mg cytosolic protein; and PGD, 76 +/- 10 mU/mg protein) or placenta (PGD, 8.0 +/- 3.6 mU/mg protein). In the liver, cSHMT activity was low early in gestation (0.6 +/- 0.5 nmol/min/mg protein at 45 days), rose in the last one-third of gestation, and peaked in the newborn period (25 +/- 3 nmol/min/mg protein at 1 week of age). Hepatic cSHMT RNA levels parallel the activity pattern. Mitochondrial SHMT was stable throughout gestation and with low constant mSHMT RNA levels. In contrast, the kidney and placenta had high mSHMT and steady low cSHMT activity throughout gestation. These data support the possible role of SHMT in the fetal control of plasma serine levels. While cSHMT may contribute to fetal hepatic serine production, its activity pattern does not support a primary role in the control of fetal hepatic serine biosynthesis. In the placenta, mSHMT may be important for glycine production from serine.