Strategies to rescue steatotic livers before transplantation in clinical and experimental studies

The shortage of donor livers has led to an increased use of organs from expanded criteria donors. Included are livers with steatosis, a metabolic abnormality that increases the likelihood of graft complications posttransplantation. After a brief introduction on the etiology, pathophysiology, categories and experimental models of hepatic steatosis, we herein review the methods to rescue steatotic donor livers before transplantation applied in clinical and experimental studies. The methods span the spectrum of encouraging donor weight loss, employing drug therapy, heat shock preconditioning, ischemia preconditioning and selective anesthesia on donors, and the treatment on isolated grafts during preservation. These methods work at different stages of transplantation process, although share similar molecular mechanisms including lipid metabolism stimulation through enzymes or nuclear receptor e.g. , peroxisomal proliferator-activated receptor, or anti-inflammation through suppressing cytokines e.g. , tumor necrosis factor-α, or antioxidant therapies to alleviate oxidative stress. This similarity of molecular mechanisms implies possible future attempts to reinforce each approach by repeating the same treatment approach at several stages of procurement and preservation, as well as utilizing these alternative approaches in tandem.

Warm HTK donor pretreatment reduces liver injury during static cold storage in experimental rat liver transplantation

BACKGROUND： Organ shortage has led to an increased number of transplantations from extended criteria donors. These organs are more vulnerable to ischemia-reperfusion injury. Thus, improvement of organ preservation is needed. HTK is a widely used preservation solution for static cold storage in liver transplantation. The present study was to investigate the beneficial effect of warm HTK donor pretreatment on liver preservation.

Inhibitory effects of two oligosaccharideson murine melanoma experimental liver metastasis

AIM To observe the effects of a chemically synthesized tetrose and a natural yeast mannan on experimental liver metastasis of mouse melanoma. METHODS After treated with 4mg tetrose (tetrose group) or 4mg mannan (mannan group) for 30 minutes at 37℃, 0 5ml 1×10 6 B16 MBK melanoma cells were injected into the spleen of mice. Fifty five days later, melanoma metastatic nodes on the surface of the liver and in other organs as well as mouse survival time were observed. RESULTS Of the 6 mice in control (B16 cell+PBS) group, 4 died naturally within 55 days, and 2 were killed on the 55th day. All of the 6 mice had metastases in livers, the total number of the melanoma nodes on each liver surface ranged from 2 to 30, with the largest one merging into the whole liver. One mouse had a neoplasm in the remnant site of injection, and 3 had metastases in lungs. In contrast, of the 6 mice in tetrose group, only one died on the 50th day after injection, with 3 metastases in the liver, the largest being 10mm in diameter, the other 5 mice survived until being dissected on the 55th day after injection and had no liver metastasis, but 3 of them had neoplasms in their remnant sites of injection. In mannan group, all of the 6 mice survived and no metastasis was seen except for 2 liver nodes in one mouse with the largest diameter of 1mm. Neither tetrose nor mannan group had metastasis out of the liver, and the weight of liver in the two groups was significantly lower than those in the control group. CONCLUSION Both tetrose and mannan had the effects of preventing melanoma cells from experimental metastasis to and out of the liver, and prolonging the survival time of the mouse.

Immunohistochemical study on expression of epidermal growth factor receptor at hepatocyte nuclei in experimental rat liver cirrhosis

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DYNAMIC CHANGES OF ITO CELLS IN EXPERIMENTAL LIVER CIRRHOSIS OF RAT

That Ho cells in rat liver express desmin was confirmed by immunohistochemical technique. Consequently, changes of desmin-positive cells, lysozyme-positive cells and fibronectin were further studied in experimental cirrhosis of rat. It was found that desmln- positive cells, with the transitional feature between Ito cells and myofibroblasts or fibrobiasts under electron microscope, increased in number and expression of desmin in the necrotic areas as well as in the cellular fibrous septa, but decreased in number in the fibrous septa except those areas closed to the edges of the septa. These results suggested that Ito cells, myofibroblasts and fibroblasts might belong to the same cellular system and play an important role in the pathogenesis of cirrhosis. Meanwhile, it was also noted that changes of both fibronectin and lysozymepositive cells were correlated with those of desmin-positive cells. These provide evidence in vivo that flbronectin and Kupffer cells might exert certain effects on the migration and proliferation of Ito cells in liver cirrhosis.

Bone disorders in experimentally induced liver disease in growing rats

AIM： To investigate the change of bone parameters in a new model of experimentally induced liver cirrhosis and hepatocellular carcinoma （HCC） in growing rats. METHODS： Fischer-344 rats （n = 55） were used. Carbon tetrachloride （CCh）, phenobarbital （PB）, and a single diethylnitrosamine （DEN） injection were used. Animals were killed at wk 8 and 16. Bone mineral content, femoral length, cortical index （quotient of cortical thickness and whole diameter） and ultimate bending load （Fmax） of the femora were determined. The results in animals treated with DEN＋PB＋CCh （DPC, n = 21） were com- pared to those in untreated animals （UNT, n = 14） and in control group treated only with DEN＋PB （DP, n = 20）. RESULTS： Fatty liver and cirrhosis developed in each DPC-treated rat at wk 8 and HCC was presented at wk 16. No skeletal changes were found in this group at wk 8, but each parameter was lower （P〈0.05 for each） at wk 16 in comparison to the control group. Neither fatty liver nor cirrhosis was observed in DP-treated animals at any time point. Femoral length and Fmax values were higher （P〈0.05 for both） in DP-treated animals at wk 8 compared to the UNT controls. However, no difference was found at wk 16. CONCLUSION： Experimental liver cirrhosis and HCC are accompanied with inhibited skeletal growth, reduced bone mass, and decreased mechanical resistance in growing rats. Our results are in concordance withthe data of other studies using different animal models. A novel finding is the transiently accelerated skeletal growth and bone strength after a 8-wk long phenobarbital treatment following diethylnitrosamine injection.

An experimental and clinical study of liver fibrosis

The studies were focused on the mechanisms of liver fibrosis and the methods to assess early stage of liver fibrogenesis. On the basis of their 13 years'studies and recent views on hepatic fibrosis,the authors find:(1) Accumulation of extracellular matrix(ECM) in liver fibrogenesis is the result of the increased mRNA of collagens and other connective tissue components;(2) The process of ECM increase is regulated by cytokines;(3) Consequsence of excess deposition of ECM in liver leads to liver injuries,giving rise to' sinusoidal caparilization',a typical change in fibrotic liver:(4) Assay of the serum components of ECM in patients with chronic liver diseases may be a good test for early diagnosis of liver fibrosis.

Regulating effect of Chinese herbal medicine on the peritoneal lymphatic stomata in enhancing ascites absorption of experimental hepatofibrotic mice

AIM: To observe the regulatory effect of Chinese herbal medicine on peritoneal lymphatic stomata and its significance in treating ascites in liver fibrosis model mice. METHODS: Two Chinese herbal composite prescriptions were used separately to treat the carbon tetrachloride-induced mouse model of liver fibrosis. The histo-pathologic changes of the liver sections (HE and VG stainings) were observed. The peritoneal lymphatic stomata was detected by scanning electron microscopy and computer image processing. The changes of urinary volume and sodium ion concentration were measured. RESULTS: In the model group, lots of fibrous tissue formed in liver and extended into the hepatic lobules to separate them incompletely. In the treated and prevention groups, the histo-pathologic changes of liver was rather milder, only showed much less fibrous tissue proliferation in the hepatic lobules. The peritoneal lymphatic stomata enlarged with increased density in the experimental groups (diameter: PA, 3.07 +/- 0.69 microm; PB, 2.82 +/- 0.37 microm; TA, 3.25 +/- 0.82 microm and TB, 2.82 +/- 0.56 microm; density: PA, 7.11 +/- 1.90 stomata.1000 microm(-2); PB, 8.76 +/- 1.45 stomata.1000 microm(-2); TA, 6.55 +/- 1.44 stomata.1000 microm(-2)and TB, 8.76+/-1.79 stomata.1000 microm(-2)), as compared with the model group (diameter: 2.00+/-0.52 microm density: 4.45+/-1.05 stomata.1000 microm(-2)). After treatment, the urinary volume and sodium ion excretion increased in the experimental groups (PA, 231.28+/-41.09 mmol.L(-1); PB, 171.69 +/- 27.48 mmol.L(-1) and TA, 231.44 +/- 34.12 mmol.L(-1)), which were significantly different with those in the model group (129.33 +/- 36.75 mmol.L(-1)). CONCLUSION: Chinese herbal medicine has marked effects in alleviating liver fibrosis, regulating peritoneal lymphatic stomata, improving the drainage of ascites from peritoneal cavity and causing increase of urinary volume and sodium ion excretion to reduce the water and sodium retention, and thus have favorable therapeutic effect in treating ascites.

Kupffer cell and apoptosis in experimental HCC

INTRODUCTION Our previous study has proved that Kupffer cellsmay have an inhibitory effect on the process ofhepatocarcinogenesis,however,their inhibitorymechanism needs exploring deeply.We performed acomparative study on the expression of PCNA,Bax,P53 and apoptosis of liver cancer cells usingimmunohistochemical technology and terminaldeoxynucleotidyl transferase (TdT)-mediateddUTP-digoxigenin nick end labeling(TUNEL)

Thrombospondin-1 expression correlates with angiogenesis in experimental cirrhosis

AIM:To investigate the significance of Thrombospondin-1 (TSP-1) expression and its relationship with angiogenesis during experimental fibrosis. METHODS:Cirrhosis was induced in male Wistar rats by intraperitoneal administration of diethyl nitrosamine (DEN). The serial sections from liver tissues were stained with anti-CD34 and anti-TSP-1 antibodies before being quantitated by light microscopy. RESULTS:Our results showed that of TSP-1 expression gradually increases according to the severity of fibrosis (GroupⅠvs group Ⅱ, Group Ⅲ and Group Ⅳ;Group Ⅱ vs group Ⅲ and group Ⅳ;group Ⅲ vs group Ⅳ, P < 0.05). Moreover, TSP-1 expression was found to be correlated with angiogenesis (P < 0.05). CONCLUSION:The correlative evidence of the link between TSP-1 and fibrosis or angiogenesis provided by this study suggests that besides its role as a strong promoter of transforming growth factor-β1 (TGF-β1), TSP-1 might have an additional role in liver fibrogenesis by stimulating angiogenesis and this protein could be a potential target to prevent fibrogenesis in chronic inflammatory diseases of the liver.

Hepatitis C Virus Experimental Model Systems and Antiviral drug Research

An estimated 130 million people worldwide are chronically infected with hepatitis C virus (HCV) making it a leading cause of liver disease worldwide. Because the currently available therapy of pegylated interferon-alpha and ribavirin is only effective in a subset of patients, the development of new HCV antivirals is a healthcare imperative. This review discusses the experimental models available for HCV antiviral drug research, recent advances in HCV antiviral drug development, as well as active research being pursued to facilitate development of new HCV-specific therapeutics.

History,ethics,advantages and limitations of experimental models for hepatic ablation

Numerous techniques developed in medicine require careful evaluation to determine their indications,limitations and potential side effects prior to their clinical use.At present this generally involves the use of animal models which is undesirable from an ethical standpoint,requires complex and time-consuming authorization,and is very expensive.This process is exemplified in the development of hepatic ablation techniques,starting experiments on explanted livers and progressing to safety and efficacy studies in living animals prior to clinical studies.The two main approaches used are ex vivo isolated non-perfused liver models and in vivo animal models.Ex vivo non perfused models are less expensive,easier to obtain but not suitable to study the heat sink effect or experiments requiring several hours.In vivo animal models closely resemble clinical subjects but often are expensive and have small sample sizes due to ethical guidelines.Isolated perfused ex vivo liver models have been used to study drug toxicity,liver failure,organ transplantation and hepatic ablation and combine advantages of both previous models.

Changes of activity of liver glycogen synthase in experimental diabetes mellitus rats

OBJECTIVE: To study the activity of liver glycogen synthase in analogous model of NIDDM rats. METHODS: Male Wistar rats were injected with low dose of streptozotocin (STZ) (30 mg/kg body weight) via tail vena and those animals with glucose tolerance impaired and level of insulin equal to or higher than that of the controls at 18th week were taken as the analogous rat model of NIDDM. The activity of liver glycogen synthase (GS) was assayed at the end of experiment. RESULTS: Type I-enzyme: 0.18 +/- 0.06 mumol/min.g versus 0.24 +/- 0.09 mumol/min.g, P

Experimental Podophyllotoxin (Bajiaolian) Poisoning:——Ⅱ. Effects on the Liver, Intestine, Kidney, Pancreas and Testis

Young male rats were orally intubated with podophyllotoxin: Group I, control animals, orally fed with vehicle only; Group Ⅱ, fed with an initial dose of 5 mg.kg-1 b.w., followed by a daily dose of 1.67 mg-kg-1 b.w. for 7d. Group III, fed with an initial dose of 15 mg.kg-1 b.w., followed by a daily dose of 5 mg.kg-1 b.w. for 7d. All animals were sacrificed 72 h after the last dosing.Histopathological examination revealed dose-related fatty change of the liver, atrophy andi degenerative changes of the intestinal epithelial linings and testicular seminiferous tubules. Depletion of the pancreatic acinar cell granules was also apparent in the Group III animals. No pathology, however, was observed in the kidneys. The present study demonstrated for the first time degenerative changes in the liver, intestine, testis, and pancreas of animals ingested podophyllotoxin. These pathological changes correlate well with the clinical signs/symptoms of abnormal liver function, abdominal pain and diarrhea, and reduced serum amylase in humans poisonded by podophyllum. Inhibition of protein synthesis and mitosis (disruption of microtubules) are believed to be the underlying mechanisms of these changes observed in the animals intoxicated by. podophyllotoxin.

EXPERIMENTAL PRIMARY LIVER CANCER IN TREE SHREWS EXPOSED TO HUMAN HEPATITIS B VIRUS AND AFLATOXIN B_(1)

On the basis of the successful establishment of an animal model in tree shrews experimentally in fected with human hepatitis B virus (HHBV), a study on the hepatocarcinogenic effects of HHBV and aflatoxin B1 (AFB1) by using this animal model was conducted through a lifelong experiment. Among 41 tree shrews exposed to AFB1, 17 were experimentally infected by HHBV and 24 were uninfected. After 158 weeks, significant difference of primary liver cancer (PLC) incidence was present between the HHBV infected (52.94%) and uninfected (12.5%) groups (p<0.05). No difference was found between these two groups in the amount of AFB4 ingestion. Moreover, 1/9 of the tree shrews infected only by HHBV but not exposed to AFB4 developed PLC. No PLC was found in 6 tree shrews that had neither been infected with HHBV nor been exposed to AFB4. These results suggest the possible etiologic relationship between HHBV infection and PLC, as well as the synergetic effects of HHBV and AFB4 during PLC development.

不同双能CT虚拟单能谱图像衍生影像组学特征的可重复性:实验研究

目的比较3种双能CT(DECT)系统在不同条件下所获VX2兔肝肿瘤模型虚拟单能谱图像(VMI)增强CT影像组学特征(RF)的可重复性及其与诊断效能的关系。方法将15只VX2兔肝肿瘤模型随机均分为3组,分别接受采用双源DECT(dsDECT)、快速kV切换DECT(rsDECT)或双层探测器DECT(dlDECT)于不同体积CT剂量指数(CTDIvol)(6、9及12 mGy)下腹部增强CT扫描,于40~140 keV内每间隔10 keV重建单能图像并提取RF;以组内相关系数(ICC)计算RF可重复性,以ICC≥0.80为可重复RF,比较不同CT仪配对之间及不同CTDIvol下可重复RF占比(R),以及相同CTDIvol下不同CT仪配对可重复RF数量(N)最大值相应重建能量水平;绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),比较最佳可重复条件下可重复RF与其他RF的诊断效能,计算RF的ICC与相应AUC的Spearman相关系数。结果R rsDECT-dsDECT[6.45%,95%CI(2.36%,8.87%)]高于R dlDECT-dsDECT[0.72%,95%CI(0.15%,1.79%)]及R rsDECT-dlDECT[1.43%,95%CI(0.60%,4.06%)](校正P均<0.05);R_(9mGy)[3.70%,95%CI(1.31%,5.73%)]及R_(12mGy)[2.63%,95%CI(0.60%,6.69%)]高于R_(6mGy)[1.31%,95%CI(0.12%,1.55%)](校正P均<0.05)。6、9及12 mGy下,RF最佳可重复重建能量水平集中于50~70 keV,可重复RF的AUC均高于其他RF(校正P均<0.05),且RF可重复性与诊断效能相关(r s=0.102~0.516,P<0.05)。结论兔肝肿瘤模型VMI CT增强图像RF可重复性与DECT设备、CTDIvol水平及重建能量水平相关,可重复RF可能诊断效能更佳。

冷循环液温度对微波消融离体猪肝消融灶形态的影响

目的观察冷循环液温度对微波消融(MWA)离体猪肝消融灶形态的影响。方法将20块新鲜离体猪肝组织随机分为冰水冷循环组(A组)及常温冷循环组(B组),分别以不同消融功率(50、60、70 W)及消融时间(1、5 min)于各亚组,即A1与B1(50 W,1 min)、A2与B2(50 W,5 min)、A3与B3(60 W,1 min)、A4与B4(60 W,5 min)、A5与B5(70 W,1 min)及A6与B6(70 W,5 min)亚组内各消融10个靶区。对比A、B组相同条件亚组间及组内消融灶形态,包括消融灶纵向直径(LD)、横向直径(TD)、球形指数(RI)及体积(V)。结果相同消融功率及时间下,A组各亚组消融灶LD均小于B组(P均<0.05);A1与B1、A2与B2、A4与B4、A5与B5、A6与B6亚组之间,前者消融灶RI均大于后者(P均<0.05),而A3与B3亚组间消融灶RI差异无统计学意义(P>0.05)。冷循环液温度对2组消融灶TD(F=1.125)和V(F=3.332)的主效应均不显著(P均≥0.05)。相同冷循环液温度条件下,A1与A2、A3与A4、A5与A6各亚组间消融灶形态各参数差异均有统计学意义(P均<0.05),B组各亚组间亦然。结论以恒定消融功率及时间行MWA消融离体猪肝时,采用冰水冷循环可使消融灶形态更接近于球形;且随消融时间延长,消融灶范围越大,则RI越高。

Safe upper limit of intermittent hepatic inflow occlusion for liver resection in cirrhotic rats

AIM: To evaluate the effects of varying ischemic durations on cirrhotic liver and to determine the safe upper limit of repeated intermittent hepatic inflow occlusion. METHODS: Hepatic ischemia in cirrhotic rats was induced by clamping the common pedicle of left and median lobes after non-ischemic lobes resection. The cirrhotic rats were divided into six groups according to the duration and form of vascular clamping: sham occlusion (SO), intermittent occlusion for 10 (IO-10), 15(IO-15), 20(IO-20) and 30(IO-30) minutes with 5 minutes of reflow and continuous occlusion for 60 minutes (CO-60). All animals received a total duration of 60 minutes of hepatic inflow occlusion. Liver viability was investigated in relation of hepatic adenylate energy charge (EC). Triphenyltetrazollum chloride (TTC) reduction activities were assayed to qualitatively evaluate the degree of irreversible hepatocellular injury. The biochemical and morphological changes were also assessed and a 7-day mortality was observed. RESULTS: At 60 minutes after reperfusion following a total of 60 minutes of hepatic inflow occlusion, EC values in IO-10 (0.749 +/- 0.012) and IO-15 (0.699 +/- 0.002) groups were rapidly restored to that in SO group (0.748 +/- 0.016), TTC reduction activities remained in high levels (0.144 +/- 0.002 mg/mg protein, 0.139 +/- 0.003 mg/mg protein and 0.121 +/- 0.003 mg/mg protein in SO, IO-10 and IO-15 groups, respectively). But in IO-20 and IO-30 groups, EC levels were partly restored (0.457 +/- 0.023 and 0.534 +/- 0.027) accompanying with a significantly decreased TTC reduction activities (0.070 +/- 0.005 mg/mg protein and 0.061 +/- 0.003 mg/mg protein). No recovery in EC values (0.228 +/- 0.004) and a progressive decrease in TTC reduction activities (0.033 +/- 0.002 mg/mg protein) were shown in CO-60 group. Although not significantly different, the activities of the serum aspartate aminotransferase (AST) on the third postoperative day (POD(3)) and POD(7) and of the serum alanine aminotransferase (ALT) on POD(3) in CO-60 group remained higher than that in intermittent occlusion groups. Moreover, a 60% animal mortality rate and more severe morphological alterations were also shown in CO-60 group. CONCLUSION: Hepatic inflow occlusion during 60 minutes for liver resection in cirrhotic rats resulted in less hepatocellular injury when occlusion was intermittent rather than continuous. Each period of 15 minutes was the safe upper limit of repeated intermittent vascular occlusion that the cirrhotic liver could tolerate without undergoing irreversible hepatocellular injury.

科教融合在生物工程专业实验教学中的应用探讨——以人参皂苷CK抗肝癌靶点的虚拟筛选为例

生化分离工程实验在生物工程专业创新性人才培养的过程中起着重要作用。本文以“人参皂苷CK抗肝癌靶点的虚拟筛选”实验为例,探讨了将其作为生化分离工程综合实验教学的可行性。通过将该实验融入生物工程专业实验教学不仅可以增强学生对专业知识的理解,而且可以拓宽学生对前沿科学发展的认知和视野,从而激发学生的学习兴趣和学习动力并在学习过程中培养他们对现代工具的使用能力和创新性思维。

Experimental study on antitumor effect of arsenic trioxide in combination with cisplatin or doxorubicin on hepatocellular carcinoma

INTRODUCTIONThe main component of a traditional Chinese drug 'Pishuang'. arsenic trioxide (As2O3), has obviously selective anti-tumor effect on human hepatocellular carcinoma (HCC)in both in vitro and in vivo studies[1-5]. Due to limited effectiveness when any anti-carcinogen is used alone and obviously increased toxicity when the dose is raised, there is no exception for As2O3. Furthermore, combined chemotherapy contributes to improve therapeutic effectiveness, disperse toxicity and surmount drug-resistance,in which the combination of traditional Chinese and modern medicine has more advantages and characteristics. As a result,we made an experimental study on anti-tumor effect of As2O3in combination with cisplantin (PDD) or doxorubicin (ADM)on HCC. to investigate the possibility of AS2O3 in combination with PDD or ADM and nature of interaction between them,and to provide experimental basis for clinical application.