Immune tolerance refers to the specific non-response or negative response of T and B lymphocytes to antigens.According to the period of formation,immune tolerance can be classified into central tolerance and peripheral tolerance.Immune tolerance to hepatitis B virus (HBV) after HBV infection is considered a major cause of chronic HBV infection.This article briefly reviews the roles of HBeAg,functional defects of dendritic cells,low response of cytotoxic T lymphocytes,T helper cells and cytokines,variations of HBV genotype and genome,and host gene polymorphisms in the development of immune tolerance in chronic HBV infection,as well as related research advances.

Inthe past few years, the study on gene therapy has achieved significant progress. However, many issues concerning ethics, safety and techniques inadequacy still exist in gene therapy and need to be solved. This article gives a brief introduction about the history, progress and presently existing problems of gene therapy. Meanwhile, it has put forward the counter measures for solving the existing problems.

Objective To investigate transfusion transmitted virus (TTV) infection among population of different groups in Shaanxi Province. Methods A nested polymerase chain reaction (PCR) with primers from ORF1 of TTV genome was established to detect TTV-DNA in serum of the patients. ResultsTTV-DAN was detected in the sera of 3 of 50 cases of general population(6％), 2 of 30 cases of vocational blood donors(6.7%),21 of 97 cases with Type B hepatitis (21. 6％), 9 of 35 cases of Type C hepatitis (25. 7％),and 23 of 40 cases with non-A～ non-G hepatitis (57.5 ％ ). ConclusionThere is TTV infection among general population in Shaanxi Province. TTV may be an impor- tant agent to cause non-A～non-G hepatitis. And the patients with HBV or HCV can have overlapping TTV infection.

Because of the specificity of infectious diseases , the the medical ethics education and concepts need to be paid more attention to .During the clinical teaching of infectious diseases , pay attention to teachers′medical ethics accomplishment level of ascension , teaching teachers should play the role of shape model , encourage interac-tion, eliminate the fear and discrimination interns and strengthen medical ethics consciousness and the combination of legal concepts , promote the medical students medical ethics consciousness of the form .

Objective To determine whether Cox-2 inhibitor can reduce the risk of cardia carcinoma. Methods Paraffin-embedded specimens from 48 patients with esophageal, gastric or cardia carcinomas were analyzed by immunohistochemistry for expression of Cox-2 protein. Expression of Cox-2mRNA was assessed by RT-PCR and ISPCR in 29 cases of them. None of these patients were currently taking NSAIDs or glucocorticoid. Results The staining scores were 4.15?1.9 in the group with esophageal cancer, 3.66?1.16 in the group with gastric cancer, and 2.93?1.03 in the group with cardia cancer, respectively. There was no significant difference between groups of gastric cancer and cardia cancer. The ratio of cases with positive expression of Cox-2 mRNA was 87.5% in the group with cardia carcinoma, 100% in the group with esophageal cancer and the group with gastric cancer. And no significant difference was found between them. Cox-2mRNA was mainly located in cytoplasm but was found in nuclear too. No difference was found in the location of Cox-2 expression in the three kinds of cancers. Conclusion Cox-2 expression in cardia carcinoma was higher than in the normal group. Its pathological characteristics were almost the same as those in gastric and esophageal cancers. Cox-2 inhibitor possibly have a chemopreventive effect on cardia carcinoma.

Objective To investigate the changes of interleukin-18 (IL-18), tumor necrosis factor-α(TNF-α) and interferon-γ (IFN-γ) levels of liver cirrhosis induced by the composite factors of carbon tetrachloride (CCl_4) in SD rats and their significance. Methods Totally 80 male SD rats of clean class were randomly divided into normal control group (20 rats) and model groups, the latter of which were further divided into three groups according to the length of administration time, namely, 2-week group (2 wk group), 4-week group (4 wk group) and 6-week group (6 wk group), with 20 rats in each. Six rats were killed after 2 wk, 4 wk and 6 wk administration time, respectively. The rat serum levels of IL-18, TNF-α and IFN-γ and the hepatic homogenate supernatant of IL-18 were detected by ELISA; pathological changes of liver tissues were observed by HE staining. Results ① Pathological observation revealed that in the model groups hepatic cells degenerated and swelled at week 2 while large amounts of fibrosis and pseudolobules of some liver tissues occurred at week 6. ② The serum levels of IL-18, TNF-α and IFN-γ were gradually increased with the modeling time, and they were significantly higher in 6-week group than in normal control group (P<0.01). ③ The levels of hepatic homogenate supernatant of IL-18 in the model groups were elevated with liver damage, and they were significantly higher in 6-week group than in normal control group (P<0.01). Conclusion During the formation of liver cirrhosis induced by composite factors of CCl_4 in rats, IL-18, TNF-α and IFN-γ levels gradually increase, suggesting that the three cytokines play a certain role during the occurrence of liver cirrhosis in rats.

Objective To study the proliferation and apoptosis of endothelia cells in cavernous hemangioma of liver(CHL),and to find their relation with the occurrence and development of CHL.Methods Twenty two CHL speciments of resection or biopsy in our hospital were collected.Another 10 speciments of small blood vessel in portal area of normal liver tissues and 10 speciments of strawberry hemangioma were collected as contrasts .The expression of proliferating cell nuclear antigen(PCNA) was assessed with monoclonal antibody of PCNA by immunohistochemical ABC method.The apoptosis of cells was assessed by end labeling method(TUNEL).Results Proliferation index(PI) of endothelia cells in CHL was 13.27?5.79.There wasn't significant difference from PI of endothelia cells of small blood vessels in portal aera of normal liver(10.85?4.79),while significant difference did exist compared with PI of tumor cells in strawberry hemangioma ( 29.31 ?8.55). Apoptosis index(AI) of endothelia cells in CHL was (3.49?1.36).There wasn't significant difference from AI of endothelia cells of small blood vessels in portal aera of normal liver(2.65?1.06),while significant difference did exist compared with AI of tumor cells in strawberry hemangioma ( 11.38 ?2.66,t=11.18,P

OBJECTIVE:To study the preventive effect of emodin and astragalus polysaccharides on experimental hepato-carcinoma in rats.METHODS:The experimental rats were randomly divided into the normal group,model group,emodin group,and emodin combined with astragalus polysaccharides group.hepatocarcinogenesis in rat models were induced by di-ethylnitrosamine,while at the same time all the groups were administered with pre-set drugs by stomach irrigation.Rat's we_ ight,serum indices of ALT,ALP,?-GT,?-L-fucoxidase were determined,and pathological examination was made before and after administration.RESULTS:The group administered with emodin and astragalus polysaccharides improved more than any other groups in terms of rat's weight,serum indices,onset time of hepatocarcinogenesis,and pathological grade.CONCLU_ SION:Emodin combined with astragalus polysaccharides have certain preventive effect on experimental hepatocarcinoma in rats.

OBJECTIVE:To observe the clinical outcome of lipid microspheres prostaglandin E 1 (Lipo-PGE 1 )injection in combination with diammonium glycyrrhizinate injection plus combined therapy in the treatment of chronic severe hepati-tis.METHODS:68patents with severe hepatitis B were assigned to receive lipid Lipo-PGE 1 injection in combination with di-ammonium glycyrrhizinate injection(treatment group)besides the necessary combined therapy as in the control group for4weeks,the clinical outcome and biochemical indicators were compared between2groups.RESULTS:As compared with the control group,the treatment group had a significantly alleviated clinical symptoms after treatment for2weeks and4weeks(P

OBJECTIVETo investigate the efficacy and safety of antiviral treatment in patients with hepatitis C virus (HCV) infection and decompensated cirrhosis and determine the effects of virological response on long-term prognosis.

METHODSSixty-six consecutive,interferon (IFN)-na(i)ve patients with HCV infection and decompensated cirrhosis were enrolled in this prospective study. All patients were given a 48-to 72-week course of IFN plus ribavirin (RBV) combined therapy,with a low accelerating dosage regimen using either:pegylated (PEG)-IFNa-2b at 1.0-1.5 mug/kg/week,PEG-IFNa-2a at 90-180 mug,or standard IFN-a-2b at 3MU,every other day.RBV was given at 800 to 1000 mg/day. All patients were routinely monitored for adverse drug reactions and virological response.Effects of treatments on patient survival were assessed by Kaplan-Meier analysis.

RESULTSAt the end of treatment,74.2% of patients were HCV RNA-negative,with 45.5% having achieved sustained virological response and 28.8% having relapsed;the remaining 25.7% of patients showed non-virological response (NVR). Among the patients with HCV genotype 1, 65.9% achieved end-of-treatment virological response (ETVR) and 34.1% achieved SVR;among the patients with HCV genotype 2,90.9% achieved ETVR and 68.2% achieved SVR. The positive and negative predictive values of early virological response (EVR) for ETVR were 95.7% and 75.0% respectively, and for SVR were 65.2% and 100% respectively. Compared with baseline,patients who achieved ETVR had better liver function,as evidenced by changes in levels of total bilirubin,alanine aminotransferase and albumin,as well as prothrombin activity and Child-Pugh score (t =4.564,11.486,2.303,2.699,3.694 respectively, all P less than 0.05).Compared with the NVR patients, the ETVR patients had lower risk of hepatic decompensation and hepatocellular carcinoma, and had improved survival (x2=18.756,6.992,7.580, respectively, all P less than 0.05).Twelve (18.2%) patients experienced serious adverse events,with 10 requiring premature treatment withdrawal and 2 dying.

CONCLUSIONAntiviral treatment for patients with HCV infection and decompensated cirrhosis using interferon in a low accelerating dosage regimen in combination with ribavirin is feasible.Patients who achieved ETVR had significantly improved long-term prognosis.

Alanine Transaminase ; Antiviral Agents ; therapeutic use ; Carcinoma, Hepatocellular ; Drug Therapy, Combination ; Genotype ; Hepacivirus ; genetics ; Hepatitis C ; diagnosis ; drug therapy ; Humans ; Interferon-alpha ; therapeutic use ; Kaplan-Meier Estimate ; Liver Cirrhosis ; drug therapy ; virology ; Liver Neoplasms ; Polyethylene Glycols ; therapeutic use ; Prospective Studies ; Recombinant Proteins ; therapeutic use ; Ribavirin ; therapeutic use ; Treatment Outcome