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Yu-Ming Wang

Publications and source records attributed to Yu-Ming Wang.

35 records · Page 2Linked to original sources
PubMed2004

Effects of hemoperfusion adsorption and/or plasma exchange in treatment of severe viral hepatitis: a comparative study.

AIM: Non-bioartificial liver has been applied to clinic for quite a long time, but the reported efficacy has been very different. The aim of this study was to compare the efficacy and safety of hemoperfusion adsorption, plasma exchange and plasma exchange plus hemoperfusion adsorption in treatment of severe viral hepatitis. METHODS: Seventy-five patients with severe viral hepatitis were treated with hemoperfusion adsorption therapy (24 cases), plasma exchange therapy (17 cases) and plasma exchange plus hemoperfusion adsorption therapy (34 cases). The data of liver function, renal function, blood routine test, prothrombin time (PT) and prothrombin activity (PTa) pre- and post-therapy were analyzed. RESULTS: Clinical symptoms of patients improved after treatment. The levels of aminotransferase, total bilirubin, direct bilirubin decreased significantly after 3 therapies (P<0.05 or P<0.01). PT, the level of total serum protein decreased significantly and PTa increased significantly after plasma exchange therapy and plasma exchange plus hemoperfusion adsorption therapy (P<0.05 or P<0.01). The side effects were few and mild in all patients. CONCLUSION: Three therapies were effective in the treatment of severe viral hepatitis. Plasma exchange therapy and plasma exchange plus hemoperfusion adsorption therapy are better than hemoperfusion adsorption therapy.

Adult↗
PubMed2004

Cryopreservation and gel collagen culture of porcine hepatocytes.

AIM: To study the method of cryopreserving porcine hepatocytes and gel collagen culture measure after its cryopreservation. METHODS: Hepatocytes, isolated from Chinese experimental suckling mini-pigs by two-step perfusion with collagenase using an extra corporeal perfusion apparatus, were cryopreserved with 50 mL/L to 200 mL/L DMSO in liquid nitrogen for 4 mo, then thawed and seeded in 1 or between 2 layers of gel collagen. The expression of porcine albumin message RNA, cellular morphology and content of aspartate aminotransferase (AST) and urea nitrogen (UN) were examined during culture in gel. RESULTS: Viability of 150 mL/L DMSO group thawed hepatocytes was (83+/-4)%, but after purification, its viability was (90+/-5)%, attachment efficiency was (86+/-7)%, the viability of thawed hepatocytes was near to fresh cells. When the thawed hepatocytes were cultivated in gel collagen with culture medium adding epidermal growth factor, the hepatocytes grew in various administrative levels in mixed collagen gel, and bunchy in the sandwich configuration cultures. For up to 10 days' culture, the typical cellular morphological characteristics of cultivated hepatocytes could be observed. The leakage of AST was lower during culture in gel than that in common culture. At the same time, the UN synthesized by cells cultivated in mixed gel collagen was higher than that in other groups. CONCLUSION: Storage in liquid nitrogen can long keep hepatocytes' activities, the concentration of 150 mL/L DMSO is fit for porcine hepatocytes' cryopreservation. Thawed hepatocytes can be cultivated with collagenous matrix, which provides an environment that more closely resembles that in vivo and maintain the expression of certain liver-specific function of hepatocytes.

Animals↗
PubMed2004

Sensitive and specific detection of strains of Japanese encephalitis virus using a one-step TaqMan RT-PCR technique.

A rapid, sensitive, and accurate laboratory diagnostic test is needed for distinguishing Japanese encephalitis virus (JEV) from other diseases featuring similar clinical symptoms and also for preventing potential outbreaks. In this study, a TaqMan reverse transcription (RT)-polymerase chain reaction (PCR) assay was developed for rapid detection and quantification of the viral RNA of various JEV strains. A consensus JEV NS3 region was chosen to design the primers and the TaqMan probe. The JEV TaqMan assay used the EZ-rTtH RT-PCR system featuring advantages such as a one-step, high-temperature RT reaction modality and preventing carry-over contamination. The sensitivity of the JEV TaqMan assay for detecting in vitro-transcribed JEV NS3 RNA was estimated to be one to five copies of RNA per reaction. For cultured JE virions, less than 40 plaque forming unit (PFU)/ml of virus load (corresponding to 0.07 PFU/test) could be detected. In addition, the JEV TaqMan assay could detect all seven strains of JEV tested, but provided negative results for nine other flaviviruses and encephalitis viruses tested. The JEV TaqMan assay demonstrated greater sensitivity and specificity than traditional RT-PCR methods as has been previously reported. The application of the JEV TaqMan assay herein has been shown to the sensitive detection of the JEV from both mosquito pools and also JEV-spiking human blood. The assay should be of use in diagnostic laboratory conduct and could be used to replace or complement time-consuming viral-culture methods, thus achieving more rapid, sensitive, and highly specific identification of JEV infection.

Encephalitis Virus, Japanese↗
PubMed2004

Impact of virus genotype on interferon treatment of patients with chronic hepatitis C: a multicenter controlled study.

BACKGROUND: Some factors have been reported to be associated with a greater likelihood of sustained viral response (SVR) in the interferon (IFN) treatment of chronic hepatitis C. The factors include HCV genotype, HCV RNA level in serum, state of liver disease, baseline body weight, age, sex, and race. The aim of this trial was to investigate the influence of HCV genotype on the IFN treatment of patients with chronic hepatitis C. METHODS: The genotypes of HCV virus were determined in the patients with chronic hepatitis C from several hospitals of China enrolled into the randomized, opened and controlled trial of Peg-IFN alpha-2a (pegasys) treatment, controlled with IFN-alpha-2a (roferon-A). The serum ALT levels and HCV RNA concentrations of the patients were detected before and at the end of treatment and during the follow-up. The influence of HCV genotype on the IFN treatment of patients with chronic hepatitis C was analyzed in intention-to-treat (ITT) population. RESULTS: The HCV genotypes of 202 patients were determined. Of these patients, 158(78.22%) were infected with genotype 1 HCV and 44(21.78%) with genotype non-1. The viral response at the end of treatment (ETVR) and sustained viral response (SVR) rates were 53.80% and 25.32% respectively in patients with genotype 1 HCV, but they were 61.36% and 43.18% in patients with genotype non-1. The difference of SVR between patients with genotype 1 HCV and those with genotype non-1 was significant (P=0.021). After being grouped by the used drugs, the ETVR rates of patients infected with genotype 1 and non-1 HCV were 76.83% and 80.95% in the patients treated with pegasys (P=0.686); but their SVR rates were 35.37% and 66.67% (P=0.01). The viral relapse rate of genotype 1 HCV (55.56%) was significantly higher than that of genotype non-1 HCV (23.53%) (P=0.02). In roferon-A group, the ETVR and SVR rates of patients with genotype 1 HCV were 28.95% and 14.47% respectively, which were lower but not more significant than those of patients with genotype non-1 HCV (43.48% and 21.74%). Moreover, the viral relapse rate of genotype 1 HCV (72.73%) was higher but not more significant than that of genotype non-1 HCV (50.00%) (P=0.21). CONCLUSION: HCV genotype could affect the efficacies, mainly sustained responses, of IFN treatment in patients with chronic hepatitis C, and the effects of IFN are related to drugs and therapeutic course.

Adolescent↗
PubMed2004

Alleviation of fatty liver by alpha-linolenic acid.

We compared the efficacy of alpha-linolenic acid (alpha-LNA, n-3) and linoleic acid (LA, n-6) on orotic acid (OA)-induced fatty liver in Sprague-Dawley rats. Rats were fed semi-synthetic diets containing either LA or alpha-LNA with or without 1% OA for 2 wk. OA supplementation lowered serum lipids in LA+OA groups. In addition to the decline of serum lipids in alpha-LNA groups compared to LA groups, a further decrease was found in alpha-LNA+OA groups compared to LA+OA groups. OA-containing diets significantly increased the liver weights and triacylglycerol (TG) accumulations compared with the OA-free diets. These results were attributed to the significant increases in the activities of phosphatidate phosphohydrolase (PAP), a rate-limiting enzyme of TG synthesis, and glucose-6-phosphate dehydrogenase, a fatty acid synthesis-related enzyme. However, the increase of PAP activity was significantly less in the alpha-LNA+OA group as compared with the LA+OA group. These results suggest that dietary alpha-LNA alleviates OA-induced hepatic TG accumulation through the attenuation of hepatic TG synthesis in rats.

Animals↗
PubMed2004

[Progress in type III secretion system].

Many Gram-negative bacteria use the type III secretion system (TTSS) to inject toxin proteins into host cells, then cause the plague disease, typhoid fever, diarrhea disease etc. Chaperone proteins is one of four components of MTSS and play an important role in helping the secretion of toxin proteins. Although these proteins had been found for almost ten years, the detailed function of chaperones is enigmatic. In this review, a brief introduction is given about the progress of classification, function of chaperones and characteristics of the interactions between chaperones and substrates.

Gram-Negative Bacteria↗
PubMed2003

Characterization of two mosquito STATs, AaSTAT and CtSTAT. Differential regulation of tyrosine phosphorylation and DNA binding activity by lipopolysaccharide treatment and by Japanese encephalitis virus infection.

Two mosquito STATs, AaSTAT and CtSTAT, have been cloned from Aedes albopictus and Culex tritaeniorhynchus mosquitoes, respectively. These two STATs are more similar to those of Drosophila, Anopheles, and mammalian STAT5 in the DNA binding and Src homology 2 domains. The mRNA transcripts are expressed at all developmental stages, and the proteins are present predominantly at the pupal and adult stages in both mosquitoes. Stimulation with lipopolysaccharide resulted in an increase of tyrosine phosphorylation and DNA binding activity of AaSTAT and CtSTAT as well as an increase of luciferase activity of a reporter gene containing Drosophila STAT binding motif in mosquito C6/36 cells. After being infected with Japanese encephalitis virus, nuclear extracts of C6/36 cells revealed a decrease of tyrosine phosphorylation and DNA binding activity of AaSTAT which could be restored by sodium orthovanadate treatment. Taking all of the data together, this is the first report to clone and characterize two mosquito STATs with 81% identity and to demonstrate a different response of tyrosine phosphorylation and DNA binding of these two STATs by lipopolysaccharide treatment and by Japanese encephalitis virus infection.

Amino Acid Motifs↗
PubMed2003

Conjugated linoleic acid enhances plasma adiponectin level and alleviates hyperinsulinemia and hypertension in Zucker diabetic fatty (fa/fa) rats.

Adiponectin is a recently discovered hormone secreted by adipocytes that has been reported to enhance insulin sensitivity. Although insulin resistance and/or compensatory hyperinsulinemia are considered to be involved with hypertension in obese humans, the relationship between plasma adiponectin level and obesity-related hypertension has not been fully clarified. In this study, we investigated the effect of dietary conjugated linoleic acid (CLA), reported as an insulin sensitizer, on plasma adiponectin, plasma insulin, and blood pressure in Zucker diabetic fatty (ZDF) rats. During the onset of obesity, blood pressure increased in ZDF rats. The increase, however, was prevented by dietary CLA. After 8 weeks, accumulated plasma insulin and glucose were also attenuated by CLA feeding. Dietary CLA increased plasma adiponectin levels in ZDF rats and the increase was attributed to the enhanced mRNA expression in white adipose tissue. This study provides the first evidence that dietary CLA increases plasma adiponectin level through the enhancement of mRNA expression. We speculate that the increase alleviates hyperinsulinemia and prevents the onset of hypertension in CLA-fed ZDF rats.

Adiponectin↗
PubMed2003

Cycloalliin, a cyclic sulfur imino acid, reduces serum triacylglycerol in rats.

Allium species such as onions and garlic are used as foodstuff, condiment, flavoring, and folk medicine. Onions may decrease hyperlipidemia and improve atherosclerosis. However, the ingredients in onion that are responsible for this phenomenon are not known. In the present study, we investigated the effects of cycloalliin, a sulfur-containing imino acid in onions, on lipid metabolism in Sprague-Dawley rats. When supplemented at the 0.1% and 0.3% levels to the atherogenic diet, cycloalliin reduced serum triacylglycerol (TAG) concentration by approximately 40% compared to the control. Serum cholesterol ester level also showed a tendency to decrease in cycloalliin groups. Hepatic lipid levels were comparable among the groups, although TAG and phospholipid contents were slightly higher in both cycloalliin groups. Dietary cycloalliin had no significant effect on hepatic enzyme activities responsible for TAG synthesis (phosphatidate phosphohydrolase, malic enzyme, and glucose-6-phosphate dehydrogenase (G6PDH)). In conclusion, dietary cycloalliin has serum TG-lowering effect without affecting hepatic TAG synthesis and content in rats, suggesting an alteration of lipoprotein assembly and secretion processes in the liver.

Animals↗
PubMed2003

Association between HLA class II gene and susceptibility or resistance to chronic hepatitis B.

AIM: To investigate the association between the polymorphism of HLA-DRB1, -DQA1 and -DQB1 alleles and viral hepatitis B. METHODS: HLA-DRB1, -DQA1 and -DQB1 alleles in 54 patients with chronic hepatitis B, 30 patients with acute hepatitis B and 106 normal control subjects were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) technique. RESULTS: The allele frequency of HLA-DRB1*0301 in the chronic hepatitis B group was markedly higher than that in the normal control group (17.31% vs 5.67%), there was a significant correlation between them (chi2=12.3068, Pc=0.0074, RR=4.15). The allele frequency of HLA-DQA1*0501 in the chronic hepatitis B group was significantly higher than that in the normal control group (25.96% vs 13.68%), there was a significant correlation between them (chi2=9.2002, Pc=0.0157, RR=2.87). The allele frequency of HLA-DQB1*0301 in the chronic hepatitis B group was notably higher than that in the normal control group (35.58% vs 18.87%), there was a significant correlation between them (chi2=15.5938, Pc=0.0075, RR=4.07). The allele frequency of HLA-DRB1*1101/1104 in the chronic hepatitis B group was obviously lower than that in the normal control group (0.96% vs 13.33%), there was a significant correlation between them (chi2=11.9206, Pc=0.0145, RR=18.55). The allele frequency of HLA-DQA1*0301 in the chronic hepatitis B group was remarkably lower than that in the normal control group (14.42% vs 30%), there was a significant correlation between them (chi2=8.7396, Pc=0.0167, RR=0.35). CONCLUSION: HLA-DRB1*0301, HLA-DQA1*0501 and HLA-DQB1*0301 are closely related with susceptibility to chronic hepatitis B, and HLA-DRB1*1101/1104 and HLA-DQA1*0301 are closely related with resistance to chronic hepatitis B. These findings suggest that host HLA class II gene is an important factor determining the outcome of HBV infection.

Acute Disease↗
PubMed2002

Suppression of Japanese encephalitis virus infection by non-steroidal anti-inflammatory drugs.

Japanese encephalitis virus (JEV) infection generates a rapid inflammatory response including peripheral neutrophil leucocytosis and infiltration of neutrophils into extraneural tissue. The level of inflammation correlates well with the clinical outcome in Japanese encephalitis patients. Non-steroidal anti-inflammatory drugs (NSAIDs), used medicinally for their analgesic and anti-inflammatory properties, are being considered for prevention of cardiovascular disease and cancer, as well as for treatment of human immunodeficiency virus infection. Apart from their ability to inhibit prostaglandin synthesis, the mechanisms underlying the beneficial therapeutic effects are largely unknown. We used aspirin, indomethacin and sodium salicylate to study the role of NSAIDs in JEV propagation in vitro. We found that NSAIDs suppressed JEV propagation in neuronal and non-neuronal cells. Blockade of cyclooxygenase activity by NSAIDs caused decreased production of free radicals and prostaglandins. However, these pharmacological alterations did not seem to correlate well with the antiviral effects. When cells were treated with the mitogen-activated protein kinase (MAPK) inhibitors PD 98059 and SB 203580, salicylate lost its antiviral effect. The activation of MAPK by anisomycin mimicked the action of salicylate in suppressing JEV-induced cytotoxicity. The decreased phosphorylation of extracellular signal-regulated kinase (ERK) was induced by JEV infection and the decrease in ERK was reversed by salicylate. Our data suggest that the signalling pathways of MAPK play a role in the antiviral action of salicylate.

Animals↗
PubMed2002

Genetic evolution of structural region of hepatitis C virus in primary infection.

AIM: To investigate the dynamics of hepatitis C virus (HCV) variability through putative envelope genes during primary infection and the mechanism of viral genetic evolution in infected hosts. METHODS: Serial serum samples prospectively collected for 12 to 34 months from a cohort of acutely HCV-infected individuals were obtained, and a 1-kb fragment spanning E1 and the 5' half of E2, including Thirty-three cloned cDNAs representing each specimen were assessed by a method that combined a single-stranded conformational polymorphism (SSCP) and heteroduplex analysis (HDA) method to determine the number of clonotypes hypervariable region, was amplified by reverse transcriptase PCR and cloned. Nonsynonymous mutations per nonsynonymous site (dn), synonymous mutations per synonymous site (ds), dn/ds ratio and genetic distances within each sample were evaluated for intrahost evolutionary analysis. RESULTS: Quasispecies complexity and sequence diversity were lower in early samples and a further increase after seroconversion, although ds value in the envelope genes was higher than dn value during primary infection. The trend, pronounced in most of samples, toward lower ds values in the E1 than in the 5' portion of E2. Quasispecies complexity was higher and E2 dn/ds ratio was a trend toward higher value in later samples during persistent viremia. We also found individual features of HCV genetic evolution in different subjects who were infected with different HCV genotypes. CONCLUSION: Mutations of actively replicating virus arise stochastically with certain functional constaints. A complexity quasispecies exerted by a combination of either neutral evolution or selective forces shows clear differences in individuals, and associated with HCV persistence.

Adult↗
PubMed2002

Activity of HDV ribozymes to trans-cleave HCV RNA.

AIM: To explore whether HDV ribozymes have the ability to trans-cleave HCV RNA. METHODS: Three HDV genomic ribozymes were designed and named RzC1, RzC2 and RzC3. The substrate RNA contained HCV RNA 5'-noncoding region and 5'-fragment of C region (5'-NCR-C). All the ribozymes and HCV RNA 5'-NCR-C were obtained by transcription in vitro from their DNA templates, and HCV RNA 5'-NCR-C was radiolabelled at its 5'-end. Under certain pH, temperature, appropriate concentration of Mg(2+) and deionized formamide, these ribozymes were respectively or simultaneously mixed with HCV RNA 5'-NCR-C and reacted for a certain time. The trans-cleavage reaction was stopped at different time points, and the products were separated with polyacrylamide gel electrophoresis (PAGE), displayed by autoradiography. Percentage of trans-cleaved products was measured to indicate the activity of HDV ribozymes. RESULTS: RzC1 and RzC2 could trans-cleave 26 % and 21.8 % of HCV RNA 5'-NCR-C under our reaction conditions with 2.5 mol.L(-1) deionized formamide respectively. The percentage of HCV RNA 5'-NCR-C trans-cleaved by RzC1, RzC2 or combined usage of the three ribozymes increased with time, up to 24.9 %, 20.3 % and 37.3 % respectively at 90 min point. Almost no product from RzC3 was observed. CONCLUSION: HDV ribozymes are able to trans-cleave specifically HCV RNA at certain sites under appropriate conditions, and combination of several ribozymes aiming at different target sites can trans-cleave the substrate more efficiently than using only one of them.

Base Sequence↗
PubMed2000

Effect of extracorporeal bioartificial liver support system on fulminant hepatic failure rabbits.

AIM:To evaluate the possibility of using cultured human hepatocytes as a bridge between bioartificial liver and liver transplantation.METHODS:In this experiment,the efficacy of extracorporeal bioartificial liver support system (EBLSS) consisting of spheriodal human liver cells and cultured hepatocytes supernatant was assessed in vivo using galactosamine induced rabbit model of fulminant hepatic failure.RESULTS:There was no difference of survival between the two groups of rabbits, but in the supported rabbits serum alanine aminotransferase, total bilirubin and creatinine were significantly lower and hepatocyte necrosis was markedly milder than those in control animals. In addition, a good viability of human liver cells was noted after the experiment.CONCLUSION:EBLSS plays a biologic role in maintaining and compensating the function of the liver.

Journal Article↗
PubMed1999

Experimental study of bioartificial liver with cultured human liver cells.

AIM:To establish an extracorporeal bioartificial liver support system (EBLSS) using cultured human liver cells and to study its support effect for fulminant hepatic failure (FHF).METHODS:The liver support experiment of EBLSS consisting of aggregates cultured human liver cells, hollow fiber bioreactor, and circulation unit was carried out in dizhepatic dogs.RESULTS:The viability of isolated hepatocytes and nonparenchymal liver cells reached 96%. These cells were successfully cultured as multicellular spheroids with synthetic technique. The typical morphological appearance was retained up to the end of the artificial liver experiment. Compared with the control dogs treated with EBLSS without liver cells, the survival time of artificial liver support dogs was significantly prolonged. The changes of blood pressure, heart rate and ECG were slow. Both serum ammonia and lactate levels were significantly lowered at the 3rd h and 5th h. In addition, a good viability of human liver cells was noted after 5h experiment.CONCLUSION:EBLSS playing a metabolic role of cultured human hepatocytes,is capable of compensating the function of the liver, and could provide effective artificial liver support and therapy for patients with FHF.

Journal Article↗
PubMedDate not supplied

Dietary phosphatidylcholine alleviates fatty liver induced by orotic acid.

OBJECTIVE: We compared the effect of dietary phosphatidylcholine (PC) with that of triacylglycerol (TG), both with the same fatty acid profiles, on fatty infiltration in orotic acid (OA)-induced fatty liver of Sprague-Dawley rats. METHODS: Rats were fed an OA-supplemented diets containing TG (TG+OA group) or PC (20% of dietary lipid, PC+OA group) for 10 d. Rats fed the TG diet without OA supplementation served as the basal group. RESULTS: Administering OA significantly increased the weights and TG accumulation in livers of the TG+OA group compared with the basal group. These changes were attributed to significant increases in the activities of fatty acid synthase, malic enzyme, and glucose-6-phosphate dehydrogenase, which are fatty acid synthetic enzymes, and phosphatidate phosphohydrolase, a rate-limiting enzyme of TG synthesis. However, the PC+OA group did not show TG accumulation and OA-induced increases of these enzyme activities. Further, a significant increase in the activity of carnitine palmitoyl transferase, a rate-limiting enzyme of fatty acid beta-oxidation, was found in the PC+OA group. CONCLUSIONS: Dietary PC appears to alleviate the OA-induced hepatic steatosis and hepatomegaly, mainly through the attenuation of hepatic TG synthesis and enhancement of fatty acid beta-oxidation in Sprague-Dawley rats.

Animals↗