Bone-marrow mesenchymal stem cells reduce rat intestinal ischemia-reperfusion injury, ZO-1 downregulation and tight junction disruption via a TNF-α-regulated mechanism

AIM: To investigate the effect of bone-marrow mesenchymal stem cells (BM MSCs) on the intestinal mucosa barrier in ischemia/reperfusion (I/R) injury. METHODS: BM MSCs were isolated from male Sprague-Dawley rats by density gradient centrifugation, cultured, and analyzed by flow cytometry. I/R injury was induced by occlusion of the superior mesenteric artery for 30 min. Rats were treated with saline, BM MSCs (via intramucosal injection) or tumor necrosis factor (TNF)-α blocking antibodies (via the tail vein). I/R injury was assessed using transmission electron microscopy, hematoxylin and eosin (HE) staining, immunohistochemistry, western blotting and enzyme linked immunosorbent assay.RESULTS: Intestinal permeability increased, tight junctions (TJs) were disrupted, and zona occludens 1 (ZO-1) was downregulated after I/R injury. BM MSCs reduced intestinal mucosal barrier destruction, ZO-1 downregulation, and TJ disruption. The morphological abnormalities after intestinal I/R injury positively correlated with serum TNF-α levels. Administration of anti-TNF-α IgG or anti-TNF-α receptor 1 antibodies attenuated the intestinal ultrastructural changes, ZO-1 downregulation, and TJ disruption. CONCLUSION: Altered serum TNF-α levels play an important role in the ability of BM MSCs to protect against intestinal I/R injury.

Diagnostic and therapeutic progress of multi-drug resistance with anti-HBV nucleos(t)ide analogues

Nucleos(t)ide analogues(NA) are a breakthrough in the treatment and management of chronic hepatitis B.NA could suppress the replication of hepatitis B virus(HBV) and control the progression of the disease.However,drug resistance caused by their long-term use becomes a practical problem,which influences the long-term outcomes in patients.Liver transplantation is the only choice for patients with HBV-related end-stage liver disease.But,the recurrence of HBV after transplantation often caused by the development of drug resistance leads to unfavorable outcomes for the recipients.Recently,the multi-drug resistance(MDR) has become a common issue raised due to the development and clinical application of a variety of NA.This may complicate the antiviral therapy and bring poorly prognostic outcomes.Although clinical evidence has suggested that combination therapy with different NA could effectively reduce the viral load in patients with MDR,the advent of new antiviral agents with high potency and high genetic barrier to resistance brings hope to antiviral therapy.The future of HBV researches relies on how toprevent the MDR occurrence and develop reasonable and effective treatment strategies.This review focuses on the diagnostic and therapeutic progress in MDR caused by the anti-HBV NA and describes some new research progress in this field.

Impact of non-oncological factors on tumor recurrence after liver transplantation in hepatocellular carcinoma patients

Hepatocellular carcinoma(HCC) is the most common primary neoplasm of the liver and is one of the leading causes of cancer-related death worldwide. Liver transplantation(LT) has become one of the best curative therapeutic options for patients with HCC, although tumor recurrence after LT is a major and unaddressed cause of mortality. Furthermore, the factors that are associated with recurrence are not fully understood, and most previous studies have focused on the biological properties of HCC, such as the number and size of the HCC nodules, the degree of differentiation, the presence of hepatic vascular invasion, elevated serum levels of alpha-fetoprotein, and the tumor stage outside of the Milan criteria. Thus, little attention has been given to factors that are not directly related to HCC(i.e., "non-oncological factors"), which have emerged as predictors of tumor recurrence. This review was performed to assess the effects of nononcological factors on tumor recurrence after LT. The identification of these factors may provide new research directions and clinical strategies for the prophylaxis and surveillance of tumor recurrence after LT, which can help reduce recurrence and improve patient survival.

Effects of heme oxygenase-1-modified bone marrow mesenchymal stem cells on microcirculation and energy metabolism following liver transplantation

AIM To investigate the effects of heme oxygenase-1(HO-1)-modified bone marrow mesenchymal stem cells(BMMSCs)on the microcirculation and energy metabolism of hepatic sinusoids following reduced-size liver transplantation(RLT)in a rat model.METHODS BMMSCs were isolated and cultured in vitro using an adherent method,and then transduced with HO-1-bearing recombinant adenovirus to construct HO-1/BMMSCs.A rat acute rejection model following 50%RLT was established using a two-cuff technique.Recipients were divided into three groups based on the treatment received:normal saline(NS),BMMSCs and HO-1/BMMSCs.Liver function was examined at six time points.The levels of endothelin-1(ET-1),endothelial nitric-oxide synthase(e NOS),inducible nitric-oxide synthase(i NOS),nitric oxide(NO),and hyaluronic acid(HA)were detected using an enzyme-linked immunosorbent assay.The portal vein pressure(PVP)was detected by Power Lab ML880.The expressions of ET-1,i NOS,e NOS,and von Willebrand factor(v WF)protein in the transplanted liver were detected using immunohistochemistry and Western blotting.ATPase in the transplanted liver was detected by chemical colorimetry,and the ultrastructural changes were observed under a transmission electron microscope.RESULTS HO-1/BMMSCs could alleviate the pathological changes and rejection activity index of the transplanted liver,and improve the liver function of rats following 50%RLT,with statistically significant differences compared with those of the NS group and BMMSCs group(P<0.05).In term of the microcirculation of hepatic sinusoids:The PVP on POD7 decreased significantly in the HO-1/BMMSCs and BMMSCs groups compared with that of the NS group(P<0.01);HO-1/BMMSCs could inhibit the expressions of ET-1 and i NOS,increase the expressions of e NOS and inhibit amounts of NO production,and maintain the equilibrium of ET-1/NO(P<0.05);and HO-1/BMMSCs increased the expression of v WF in hepatic sinusoidal endothelial cells(SECs),and promoted the degradation of HA,compared with those of the NS group and BMMSCs group(P<0.05).In term of the energy metabolism of the transplanted liver,HO-1/BMMSCs repaired the damaged mitochondria,and improved the activity of mitochondrial aspartate aminotransferase(ASTm)and ATPase,compared with the other two groups(P<0.05).CONCLUSION HO-1/BMMSCs can improve the microcirculation of hepatic sinusoids significantly,and recover the energy metabolism of damaged hepatocytes in rats following RLT,thus protecting the transplanted liver.

Combined Antitumor Effect of Ursolic Acid And 5-Fluorouracil on Human Esophageal Carcinoma Cell Eca-109 In Vitro

Objective： To study the combined antitumor effect and possible mechanisms of ursolic acid with 5-fluorouracil （5-FU） on human esophageal carcinoma cell Eca-109 in vitro. Methods： Eca-109 cells were treated with ursolic acid （10-50 μmol/L） and/or 5-fluorouracil （48.0-768.8 μmol/L） for 48 h in vitro. And then cell proliferation was determined by MTT assay. Cell cycle and apoptosis rate were analyzed by flow cytometry （FCM）. The morphological changes of apoptosis were observed by fluorescent microscopy. At last the expression of P27kipl, bcl-2 and bax were detected by western blot. Results： Results： In comparison with single agent treatment, the combination of ursolic acid and 5-fluorouracil produced greater efficacy in growth inhibition, cell cycle arrest at G0/G1 phase, and apoptosis induction （P〈0.05）. Western blot analysis showed that the combination use of ursolic acid and 5-fluorouracil suppressed the expression of bcl-2 and increased the expressions of bax and P27kip1. Conclusion： Ursolic acid combined with 5-fluorouracil showed adjuvant antiproliferative effects on human esophageal carcinoma cell Eca-109 in vitro, which mainly due to the induction of cell cycle arrest as well as apoptosis.

Effect of CXCR3/HO-1 genes modified bone marrow mesenchymal stem cells on small bowel transplant rejection

AIM To investigate whether bone marrow mesenchymal stem cells(BMMSCs) modified with the HO-1 and CXCR3 genes can augment the inhibitory effect of BMMSCs on small bowel transplant rejection.METHODS Lewis rat BMMSCs were cultured in vitro. Thirdpassage BMMSCs were transduced with the CXCR3/HO-1 genes or the HO-1 gene alone. The rats were divided into six groups and rats in the experimental group were pretreated with BMMSCs 7 d prior to smallbowel transplant. Six time points(instant, 1 d, 3 d, 7 d, 10 d, and 14 d)(n = 6) were chosen for each group. Hematoxylin-eosin staining was used to observe pathologic rejection, while immunohistochemistry and Western blot were used to detect protein expression. Flow cytometry was used to detect T lymphocytes and enzyme linked immunosorbent assay was used to detect cytokines.RESULTS The median survival time of BMMSCs from the CXCR3/HO-1 modified group(53 d) was significantly longer than that of the HO-1 modified BMMSCs group(39 d), the BMMSCs group(26 d), and the NS group(control group)(16 d)(P < 0.05). Compared with BMMSCs from the HO-1 modified BMMSCs, BMMSCs, and NS groups, rejection of the small bowel in the CXCR3/HO-1 modified group was significantly reduced, while the weight of transplant recipients was also significantly decreased(P < 0.05). Furthermore, IL-2, IL-6, IL-17, IFN-γ, and TNF-α levels were significantly decreased and the levels of IL-10 and TGF-β were significantly increased(P < 0.05). CONCLUSION BMMSCs modified with the CXCR3 and HO-1 genes can abrogate the rejection of transplanted small bowel more effectively and significantly increase the survival time of rats that receive a small bowel transplant.

Application of nucleoside analogues to liver transplant recipients with hepatitis B

Hepatitis B is a common yet serious infectious disease of the liver, affecting millions of people worldwide. Liver transplantation is the only possible treatment for those who advance to end-stage liver disease. Donors positive for hepatitis B virus(HBV) core antibody(HBc Ab) have previously been considered unsuitable for transplants. However, those who test negative for the more serious hepatitis B surface antigen can now be used as liver donors, thereby reducing organ shortages. Remarkable improvements have been made in the treatment against HBV, most notably with the development of nucleoside analogues(NAs), which markedly lessen cirrhosis and reduce post-transplantation HBV recurrence. However, HBV recurrence still occurs in many patients following liver transplantation due to the development of drug resistance and poor compliance with therapy. Optimized prophylactic treatment with appropriate NA usage is crucial prior to liver transplantation, and undetectable HBV DNA at the time of transplantation should be achieved. NA-based and hepatitis B immune globulin-based treatment regimens can differ between patients depending on the patients' condition, virus status, and presence of drug resistance. This review focuses on the current progress in applying NAs during the perioperative period of liver transplantation and the prophylactic strategies using NAs to prevent de novo HBV infection in recipients of HBc Ab-positive liver grafts.

慢性乙型肝炎病毒感染孕妇妊娠期肝炎发作的临床特点及抗病毒治疗的疗效评价

背景妊娠期间母体肝脏血供减少,负荷代谢增加等容易使妊娠期肝炎发作,严重者将出现肝衰竭,导致凝血机制异常,引起大量出血和感染,胎儿宫内窘迫,早产,死胎等.因此,对慢性乙型肝炎病毒(hepatitis B virus, HBV)感染孕妇治疗和管理的高度重视是降低HBV母婴传播的关键所在,也是临床医护人员关注的重要问题,尤其关注妊娠期肝炎发作的早期诊断和治疗尤为重要.目的观察慢性HBV感染孕妇妊娠期肝炎发作的临床特点及抗病毒治疗的疗效评价.方法选择2017-02/2019-06在浙江省余姚市妇幼保健院就诊的慢性HBV感染孕妇180例为研究对象,在妊娠期每4-12 wk行肝功能, HBV血清标志物检查以判断是否有妊娠期肝炎发作.对于明确诊断者即可给予口服替比夫定600 mg, 1次/d.观察慢性HBV感染孕妇妊娠期肝炎发作临床特点和丙氨酸转氨酶(alanine aminotransferase, ALT), HBV血清标志物和HBV DNA的变化,以及妊娠不同时间点抗病毒治疗后ALT复常率, HBV DNA和乙型肝炎核心抗原(hepatitis B e antigen, HBe Ag)阴转率及HBeAg血清学转换率.结果本研究纳入180例慢性HBV感染孕妇,其中48例(26.67%)孕妇妊娠期肝炎发作.年龄26-36岁,平均32.3岁±2.4岁;肝炎发作时间6-34wk,平均20.3wk±7.8wk;ALT平均值为224.95U/L±19.6U/L.与妊娠期无肝炎发作孕妇比较,妊娠期肝炎发作孕妇ALT, HBV DNA变化显著(P<0.05),乙型肝炎表面抗原和HBe Ag定量均明显降低(P<0.05).妊娠期肝炎发作孕妇随着治疗时间的延长ALT复常率, HBV DNA阴转率,HBeAg阴转率及HBeAg血清学转换率均有不同程度的升高,尤其在治疗36 wk时,孕妇ALT复常率为100.0%,HBV DNA阴转率为72.92%,HBeAg阴转率为41.67%,HBeAg血清学转换率为37.5%,均明显高于治疗6wk时、治疗12wk时和治疗24 wk的疗效,差异比较均有统计学意义(P<0.05).结论慢性HBV感染孕妇妊娠期肝炎发作多发生在妊娠中期,给予积极抗病毒治疗后在第36周时HBe Ag血清学转换率高.

Differential Polymorphic Transformation Behavior of Polybutene-1 with Multiple Isotactic Sequences

For the solid-solid transformation from form Ⅱ to form Ⅰ of isotactic polybutene-1(iPB),the temperature dependence of form Ⅰ nucleation and growth was deemed to control the transformation process.However,the relationship between formⅠ formation and form Ⅱ disappearance in the transformation process is not clear.In this work,the spontaneous crystal transformation from form Ⅱ to Ⅰ of iPB with 81 mol%mmmm sequence concentration is studied firstly by tracking the two processes,the decay of form Ⅱ and the yielding of form Ⅰ in a wide range of temperature spanning from 0℃ to 50℃ and in a long transformation time ranging from 5 min to 65 days with in situ FTIR and WAXD.Unlike the literature reports,the decay rate of form Ⅱ is firstly found to be lower than the yielding rate of form Ⅰ at all studied temperatures,especially at low transition temperature.This is attributed to the amorphous chains which locate near crystal lamella participating into the nucleation of form Ⅱ.The regular chain folding and growth of i PB form Ⅰ from amorphous chains containing short isotactic sequences also lead to an increase in crystallinity of form Ⅰ compared with that of initial form Ⅱ crystallized at 60℃.An increase in the annealing temperature results in decrease in crystallinity and increase in lamellae thickness of i PB formⅠ.

Polymerization Kinetics of Propylene with the MgCl_(2)-Supported Ziegler-Natta Catalysts——Active Centers with Different Tacticity and Fragmentation of the Catalyst

The catalytic activity and stereospecificity of olefin polymerization by using heterogeneous TiCl_(4)/MgCl_(2) Ziegler-Natta(Z-N) catalysts are determined by the structure and nature of active centers, which are mysterious and fairly controversial. In this work, the propylene polymerization kinetics under different polymerization temperatures by using Z-N catalysts were investigated through monitoring the concentration of active centers [C*] with different tacticity. SEM was applied to characterize the catalyst morphologies and growing polypropylene(PP) particles. The lamellar thickness and crystallizability of PP obtained under different polymerization conditions were analyzed by DSC and SAXS. The PP fractions and active centers with different tacticity were obtained with solvent extraction fractionation method. The catalytic activity, active centers with different tacticity and propagation rate constant kp, fragmentation of the catalyst, crystalline structure of PP are correlated with temperature and time for propylene polymerizations. The polymerization temperature and time show complex influences on the propylene polymerization. The higher polymerization temperature(60 ℃) resulted higher activity, kp and lower [C*], and the isotactic active centers Ci* as the majority ones producing the highest isotactic polypropylene(iPP) components showed much higher kp when compared with the active centers with lower stereoselectivity. Appropriate polymerization time provided full fragmentation of the catalyst and minimum diffusion limitation. This work aims to elucidate the formation and evolution of active centers with different tacticity under different polymerization temperature and time and its relations with the fragmentation of the PP/catalyst particles, and provide the solutions to the improvement of catalyst activity and isotacticity of PP.

Structure and Properties of Isotactic Polypropylene/Polybutene-1 In-reactor Alloys

The composition and structure of polymer largely determine the properties of its final products.As a novel polymer material,the composition,structure,and properties of the isotactic polypropylene/polybutene-1 in-reactor alloy(PPIPB alloy)synthesized by sequential two-stage polymerization with Ziegler-Natta catalyst were correlated for the first time in this work.The iPP/PB alloy was fractionated by temperature rising elution fractionation(TREF)in a broad temperature ranged from-30℃ to 140℃,and the chain microstructures and sequence distributions of isolated fractions were analyzed by DSC,GPC,13C-NMR,and FTIR.The iPP/IPB alloy was composed of five components,namely high isotactic PB(PB,85.8 wt96),medium isotactic PB(mPB,5.1 wt%),polyl(butene-1)-block propylene copolymers(PB-6 PP,4.1 wt%6)which contained PB and PP blocks with dfferent lengths according to the isolation temperature,isotactic PP(iPP,2.7 wt%6),and atactic PB(aPB,2.3 wt96).Compared to other commercial pipe materials,the P/iPB alloy presented outstanding thermal creep resistance and gas permeability resistance,high strength and low deformation at high temperature,and appropriate flexural strength.The roles of PP and PB-b-PP components in the alloy were interpreted.This work is expected to elucidate the potential application of PPIPB aloy as pipe materials and provide solutions for the design and synthesis of high performance pipe materials.

Clinical Features and Clonal Origin of Diffuse Hepatocellular Carcinoma

To the Editor：Diffuse hepatocellular carcinoma （D-HCC）,also known as cirrhosis-like HCC,is a rare and peculiar type of HCC.[1] The World Health Organization （WHO） defines D-HCC as follows：small tumor nodules distributed diffusely all over the liver presents like cirrhotic-associated regenerative nodules.[2] Surgical resection,radiotherapy,and medication cannot bring good results for D-HCC,and the prognosis of D-HCC is poor.