Cost-effectiveness of a school-based tobacco-use prevention program

OBJECTIVE

To determine the cost-effectiveness of a school-based tobacco-use prevention program.

DESIGN

Using data from the previously reported 2-year efficacy study of the Project Toward No Tobacco Use (TNT), we conducted a decision analysis to determine the cost-effectiveness of TNT. The benefits measured were life years (LYs) saved, quality-adjusted life years (QALYs) saved, and medical care costs saved, discounted at 3%. The costs measured were program costs. We quantified TNT's cost-effectiveness as cost per LY saved and cost per QALY saved.

INTERVENTION

A 10-lesson curriculum designed to counteract social influences and misconceptions that lead to tobacco use was delivered by trained health educators to a cohort of 1234 seventh-grade students in 8 junior high schools. A 2-lesson booster session was delivered to the eighth-grade students in the second year. The efficacy evaluation was based on 770 ninth-grade students who participated in the program in the seventh and eighth grades and in both the baseline and the 2-year follow-up survey.

RESULTS

Under base case assumptions, at an intervention cost of $16 403, TNT prevented an estimated 34.9 students from becoming established smokers. As a result, we could expect a saving of $13 316 per LY saved and a saving of $8482 per QALY saved. Results showed TNT to be cost saving over a reasonable range of model parameter estimates.

CONCLUSIONS

The TNT is highly cost-effective compared with other widely accepted prevention interventions. School-based prevention programs of this type warrant careful consideration by policy makers and program planners.

All-trans-retinoic acid increased the expression of integrin alpha5beta1 and induced "anoikis" in SMMC-7721 hepatocarcinoma cell

It is extensively shown that integrin can regulate various cellular functions, including apoptosis, probably by contributing to signal transduction processes through interaction with extracellular matrix (ECM) proteins. In the present study, DNA flow cytometric analysis demonstrated that SMMC-7721 hepatocarcinoma cells treated with 80 microM all-trans-retinoic acid (atRA) showed an increased expression of the integrin alpha5beta1, which was associated with the growth inhibition of the cells. We found that atRA treated cells showed obvious apoptosis. Then, it was postulated that the enhanced content of integrin alpha5beta1 in the absence of ligation with fibronectin (Fn) would stop transducing survival signals, and lead to decreased cell growth and apoptosis. To elucidate this hypothesis, we cultured the atRA treated cell in L-poly-lysine-coated and Fn-coated flask, respectively. The results indicated that Fn binding prevented the cells from apoptosis induced by atRA, in contrast to L-poly-lysine binding. When the transfectant with enhanced expression of integrin alpha5beta1 at the same level of atRA treated cell was cultured in L-poly-lysine-coated flask, apoptosis was triggered. However, apoptotic cell was not detected when those cells were cultured in Fn-coated flask. Meanwhile, culturing the transfectant in the antibody (against integrin alpha5 subunit)-coated flask induced 18.33% of the cells into apoptosis, which is far more than the control group. Our study suggests that increased expression of integrin alpha5beta1 on the surface of SMMC 7721 hepatocarcinoma cell treated by atRA, when unbound to Fn, would stop transducing survival signals to lead to "anoikis", and can be reverted by the interaction of integrin alpha5beta1 with Fn.

Effect of interleukin (IL)-12 and IL-15 on apoptosis and proliferation of umbilical cord blood mononuclear cells

Decreased graft-versus-host disease (GVHD) in cord blood (CB) transplantation may be attributed to the immunological immaturity and susceptibility to apoptosis of CB mononuclear cells (MNCs). Cytokines like interleukin (IL)-12 and IL-15 may be used for in vivoadministration or ex vivo expansion of lymphoid cells for more rapid recovery following stem cell transplant, and for providing a graft-versus-leukemia (GVL) effect. We investigated the effects of IL-12 and IL-15, alone or in combination on apoptosis and proliferation of both CB and adult peripheral blood (APB) MNCs, with particular emphasis on CB CD4+, CD8+ and CD56+ lymphocyte subpopulations. The results of our study indicated that: (1) the combination of IL-12+IL-15 resulted in a greater degree of CB and APB apoptosis than either cytokine alone; (2) the level of both spontaneous and cytokine-induced apoptosis by IL-12 and/or IL-15 are greater in CB MNCs than in APB MNCs using TUNEL assays; (3) IL-15 is superior to IL-12 in enhancing the proliferative response in CB and APB MNCs; (4) the combination of IL-12+IL-15, but not either cytokine alone, significantly enhanced apoptosis in CD8+ and CD56+ CB subsets, but not in CD4+ CB subsets; (5) IL-12 or IL-15 alone resulted in increased proliferation in CD4+, CD8+ and CD56+ CB subsets, with IL-12+IL-15 producing the greatest increase of proliferation in all three CB subsets; and (6) IL-15 and/or IL-12 significantly upregulate Fas (CD95) expression on CB T and NK cells. These findings may have therapeutic implications when designing cytokine therapy in patients receiving CB transplant.

[GnT-V overexpression in human hepatocarcinoma cells affects its migration and expression of cell adhesion molecules]

The purpose of this paper is to study the effect of N-acetylglucosaminyltransferase V (GnT-V) overexpression on the migration of 7721 cells and its mechanism. The abilities of migration of both 7721 cells transfected with GnT-V cDNA and 7721 cells transfected with pcDNA3 was detected, the expressions of integrin and E-cadherin which are important adhesion molecules on surface membrane and closely related to the abilities of invasion and metastasis. Cell migration abilities were measured by the agarose drop explant method. Flow cytometric analysis (FACS) was applied to determine the relative amounts of integrin alpha 5 and beta 1 subunits on the cell surface while RTPCR was carried out to determine the expression of their mRNA. The expression of E-cadherin was examined by the immunocytochemical ABC method. Western blot analysis was carried out to examine the expression of beta-catenin. GnT-V overexpression enhanced evidently the migration ability of 7721 cells and increased the amount of integrin alpha 5 subunit to 2.9 times of that of control while the amount of beta 1 subunits was not significantly changed. Besides, the expressions of E-cadherin and beta-catenin were enhanced at different levels in GnT-V/7721 cells compared with mocked. The results suggested that the overexpression of GnT-V related to the production of N-linked sugar chains could promote the expressions of integrin, E-cadherin and beta-catenin on 7721 cells so that the migration ability of tumor cells was enhanced.

Variability in aflatoxin-albumin adduct levels and effects of hepatitis B and C virus infection and glutathione S-transferase M1 and T1 genotype

Exposure to aflatoxin B1 (AFB1), an important cofactor in the etiology of hepatocellular carcinoma in Taiwan, is influenced by dietary and other factors. The present study examined the intraindividual variability in AFB1-albumin adducts, the most reliable long-term biomarker of AFB1 exposure, and whether the baseline or follow-up adduct levels and the intraindividual variability in adduct levels are modified by endogenous and environmental factors. The study measured AFB1-albumin adduct levels among 264 healthy male residents of three townships (Hu-Hsi, Ma-Kung, and Pai-Hsa) of Penghu Islets, Taiwan, at two different time points with a median interval of 1.68 years (range 1.00-3.17 years). There was a generalized reduction in the adduct levels, with the median values being 22.1 pmol/mg (range 5.0-355.8 pmol/mg) at time 1 and 14.3 pmol/mg (range 5.0-205.2 pmol/mg) at time 2. This intraindividual variability in adduct levels was inversely associated with the age of subjects and the time interval between the two blood draws. The variability in adduct levels was lower among subjects in Hu-Hsi and Pai-Hsa townships as compared to those in Ma-Kung. No significant association was observed for the intraindividual variability in AFB1-albumin adducts with regard to the season when blood was drawn. There was also no significant association between intraindividual variability and hepatitis B surface antigen, anti-hepatitis C virus (anti-HCV), glutathione S-transferase (GST) M1, or GSTT1 status. In conclusion, we found substantial intraindividual variability in the AFB1 exposure (as determined by AFB1-albumin adducts) in Taiwan, which was probably more likely related to dietary or other environmental influences rather than to endogenous factors (e.g., hepatitis B/C viral infection or GST M1/T1 genetic status).

Ultrasonic characteristics of periportal collateral circulation in hepatocellular carcinoma with portal vein invasion

Real-time ultrasound (US) was used to analyze the morphological characteristics of periportal collateral circulation (PPCC) and the hepatic artery in hepatocellular carcinoma (HCC) patients with portal vein invasion (PVI). During a 5-year interval, a total of 17 HCC patients with main portal vein thrombosis and detectable periportal vessels were collected: 14 men and 3 women, aged 27 to 76 years old. We examined these patients' periportal vessels by real-time US, then differentiated PPCC from hepatic artery by duplex Doppler US. We analyzed the morphological appearances of real-time US imaging of PPCC and the hepatic artery. Our results showed that the PPCC was always torturously worm-like in appearance on real-time US, and the hepatic artery usually had a linear channel appearance on real-time US. When these two kinds of vessels were seen simultaneously along the pathway of a thrombosed portal vein, the inner vessel was always the hepatic artery with linear channel structure, and the outer vessel was always PPCC with a torturously worm-like structure. In conclusion, real-time US is a useful and reliable modality in detecting periportal vessels and differentiating PPCC from the hepatic artery.

Genetic polymorphisms of glutathione S-transferases M1 and T1 associated with susceptibility to aflatoxin-related hepatocarcinogenesis among chronic hepatitis B carriers: a nested case-control study in Taiwan

This study was conducted to investigate the modifying effect of glutathione S-transferase (GST) M1 and T1 polymorphisms on aflatoxin-induced hepatocarcinogenesis among chronic hepatitis B virus surface antigen (HBsAg) carriers. A total of 79 HBsAg-positive cases of hepatocellular carcinoma (HCC) diagnosed between 1991 and 1997 were identified and individually matched to one or two HBsAg-positive controls on age, gender, residence and date of recruitment from the same cancer screening cohort in Taiwan. Blood samples were tested for hepatitis B and C viral markers by enzyme immunoassay and for aflatoxin B(1) (AFB(1))-albumin adducts by competitive enzyme-linked immunosorbent assay. GSTM1 and GSTT1 genotypes were determined by PCR. There was a statistically significant relationship between detectable levels of AFB(1)-albumin adducts in serum and risk of HCC among chronic HBsAg carriers, with an adjusted odds ratio (OR) of 2.0 [95% confidence interval (CI) 1.1-3.7]. In addition, the effect of aflatoxin exposure on HCC risk was more pronounced among chronic HBsAg carriers with the GSTT1 null genotype (OR 3.7, 95% CI 1.5-9.3) than those who were non-null (OR 0.9, 95% CI 0.3-2.4). The interaction between serum AFB(1)-albumin adduct level and GSTT1 genotype was statistically significant (P = 0.03). For GSTM1 the effect of aflatoxin exposure on HCC risk in those with the null genotype was also greater (adjusted OR 2.8, 95% CI 1.0-7.8) than in those with the gene present (adjusted OR 1.8, 95% CI 0.8-4.5), but the difference was not significant (P = 0.91). Notably, when the interaction between aflatoxin exposure and GSTT1 genotype was considered, aflatoxin exposure by itself was not a significant determinant of HCC risk among chronic HBsAg carriers. These results demonstrate the importance of gene-environment interactions in the multifactorial development of HCC.

Influence of hepatitis C virus on the profiles of patients with chronic hepatitis B virus infection

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the most common causes of chronic liver disease, cirrhosis and hepatocellular carcinoma. The influence of HCV infection on the clinicopathological and virological profiles of chronic HBV infection was investigated.

METHODS

A total of 100 chronic HBV carriers with histopathological diagnoses by liver biopsy were studied. Hepatitis B e antigen (HBeAg) and anti-HCV antibody were tested. Serum HCV-RNA was detected by using a nested reverse transcription-PCR assay. A branched DNA (bDNA) assay was used to detect HBV-DNA and quantitate the serum levels.

RESULTS

Eighteen (18%) of 100 patients were positive for anti-HCV and HCV-RNA. Patients with concurrent HCV and HBV infection were significantly older than those without HCV infection (P < 0.05). The positive rates of HBeAg and HBV-DNA as well as the serum levels of HBV-DNA in patients with concurrent HCV and HBV infection were significantly lower than those without concurrent HCV and HBV infection (P < 0.01, P < 0.05, and P < 0.001, respectively). By using multivariate analysis, the factors of seroconversion of HBeAg and decreasing level of HBV-DNA were significantly correlated to concurrent HCV and HBV infection in chronic HBV carriers. The factors of increasing age and concurrent HCV and HBV infection were significantly correlated to seroconversion of HBeAg.

CONCLUSIONS

The concurrent HCV and HBV infection in chronic HBV carriers might result in a suppression of HBV replication that presented with a lower level of serum HBV-DNA and HBeAg seroconversion. Nevertheless, neither more obvious increase in biochemical parameters nor histopathological progression to more advanced liver diseases was observed.

Sex differences in relation to serum hepatitis B e antigen and alanine aminotransferase levels among asymptomatic hepatitis B surface antigen carriers

This study aimed to investigate sex differences in relation to hepatitis B e antigen (HBeAg) and serum alanine aminotransferase (ALT) levels in chronic asymptomatic hepatitis B virus (HBV) infection. HBeAg and ALT level were determined in 636 asymptomatic hepatitis B surface antigen carriers. There was no significant sex differences in the age-adjusted prevalence of HBeAg. Abnormal ALT level (>45 IU/l) was more frequent in carriers with HBeAg (17.5% vs 7.6%; P = 0.001). Multivariate analysis indicated that male sex (odds ratio, 2.0; 95% confidence interval, 1.1-3.6) and HBeAg (odds ratio, 2.6; 95% confidence interval, 1.6-4.3) were independent risk factors for abnormal ALT levels. Male sex and HBeAg-positivity are independent risk factors for abnormal ALT activity in chronic HBV infection. This observation may be related to sex differences in chronic HBV infection.

An improved and easy method for the preparation of 2,2-disubstituted 1-nitroalkenes

Reactions of ketones 1, nitromethane 2, and catalytic amount of piperidine 3 in the presence of mercaptan 6 generate beta-nitroalkyl sulfides 7-9. At 0 degrees C and by the use of dichloromethane as solvent, beta-nitroalkyl sulfides 7-9 can be oxidized by m-chloroperoxybenzoic acid (m-CPBA) 10 to generate beta-nitroalkyl sulfoxides 11-13 and undergo elimination in carbon tetrachloride solution to produce medium to high yield of 2,2-disubstituted 1-nitroalkenes 5. The irreversibility of the synthetic mechanism not only can overcome the reversibility of the Henry reaction in the synthesis of 2,2-disubstituted 1-nitroalkenes 5 but also can generate the major products "exo-nitro olefins"5c-e when cyclic ketones 1c-e were used. Under similar conditions, medium to high yield of 5-substituted-2-nitromethyl-2-phenylthioadamantane 17 also can be prepared from the reaction of 5-substituted-2-adamantanones 15, nitromethane 2, piperidine 3, thiophenol 6a. The intermediate17 can be oxidized by m-CPBA 10 in dichloromethane solution and then undergo elimination at room temperature or can be dissolved in solvent, coated on silica gel, and then heated at 90-100 degrees C to generate 5-substituted-2-nitromethyleneadamantane 16.

Betel quid chewing as a risk factor for hepatocellular carcinoma: a case-control study

The role of betel quid chewing in the aetiology of hepatocellular carcinoma (HCC) was evaluated in a case-control study including 263 pairs of age- and sex-matched HCC patients and healthy controls. Serum hepatitis B surface antigen (HBsAg), and antibodies to hepatitis C virus (anti-HCV) were determined, and standardized personal interview conducted using a structured questionnaire. Multivariate analysis indicated that betel quid chewing (odds ratio (OR), 3.49; 95% confidence interval (CI), 1.74-6.96), HBsAg (OR, 16.69; 95% CI, 9.92-28.07), anti-HCV (OR, 38.57; 95% CI, 18.15-81.96), and educational duration of less than 10 years (OR, 1.71; 95% CI, 1.05-2.78) are independent risk factors of HCC. In addition, there was an additive interaction between betel quid chewing and chronic infection with either hepatitis B virus (synergy index, 5.37) or hepatitis C virus (synergy index, 1.66). Moreover, risk on HCC increased as duration of betel quid chewing increased, or amount of betel quid consumed (each P for trend < 0.0001).

Hepatoprotective effects of Arctium lappa on carbon tetrachloride- and acetaminophen-induced liver damage

The root of Arctium lappa Linne (A. lappa) (Compositae), a perennial herb, has been cultivated for a long time as a popular vegetable. In order to investigate the hepatoprotective effects of A. lappa, male ICR mice were injected with carbon tetrachloride (CCl4, 32 microl/kg, i.p.) or acetaminophen (600 mg/kg, i.p.). A. lappa suppressed the SGOT and SGPT elevations induced by CCl4 or acetaminophen in a dose-dependent manner and alleviated the severity of liver damage based on histopathological observations. In an attempt to elucidate the possible mechanism(s) of this hepatoprotective effect, glutathione (GSH), cytochrome P-450 (P-450) and malondialdehyde (MDA) contents were studied. A. lappa reversed the decrease in GSH and P-450 induced by CCl4 and acetaminophen. It was also found that A. lappa decreased the malondialdehyde (MDA) content in CCl4 or acetaminophen-intoxicated mice. From these results, it was suggested that A. lappa could protect the liver cells from CCl4 or acetaminophen-induced liver damages, perhaps by its antioxidative effect on hepatocytes, hence eliminating the deleterious effects of toxic metabolites from CCl4 or acetaminophen.

The molecular epidemiology and clinical significance of TT virus (TTV) infection in healthy blood donors from southern Taiwan

To evaluate the molecular epidemiology and clinical significance of th

Efficacy trial of Vi polysaccharide vaccine against typhoid fever in south-western China

OBJECTIVE

To test the efficacy of locally produced Vi vaccine over a time period of longer than one year.

METHODS

A double-blinded, randomized field trial was performed in Guangxi Zhuang Autonomous Region in south-western China, using 30 micrograms doses of locally produced Vi. Enrolled subjects were 3-50 years of age, although the majority (92%) were school-aged children, who have the highest rate of typhoid fever in this setting. A total of 131,271 people were systematically allocated a single dose of 30 micrograms of Vi polysaccharide or saline placebo. The study population was followed for 19 months, with passive surveillance conducted in the Ministry of Health and the Regional Health and Anti-epidemic Centre (HAEC). Clinically suspected cases of typhoid fever were confirmed by blood culture, or by serological reaction with O-antigen (Widal tests).

FINDINGS

After 19 months, there were 23 culture-confirmed cases of typhoid fever in the placebo group versus 7 cases in the Vi group (Protective efficacy (PE) = 69%; 95% CI = 28%, 87%). Most of the isolates were from school-aged children: 22 cases in the placebo group versus 6 in the Vi group (PE = 72%; 95% CI = 32%, 82%). No serious post-injection reactions were observed. The locally produced Vi polysaccharide vaccine showed levels of protective efficacy similar to those for Vi vaccine produced in industrial countries.

CONCLUSION

The slightly higher dose of vaccine did not seem to alter efficacy significantly in China.

The serological and molecular epidemiology of GB virus C/hepatitis G virus infection in a hepatitis C and B endemic area

OBJECTIVES

To investigate the serological and molecular characteristics of GB virus C/hepatitis G virus (GBV-C/HGV) infection in the hepatitis C virus (HCV)/hepatitis B virus (HBV)-endemic areas in Taiwan.

METHODS

Sera from 200 residents from Masago, an HCV/HBV-endemic community in Taiwan, and 400 blood donors were tested for GBV-C/HGV RNA by using nested reverse transcription-polymerase chain reaction and for antibodies to GBV-C/HGV E2-protein (anti-E2) by an enzyme-linked immunosorbent assay. Phylogenetic analysis of GBV-C/HGV was performed.

RESULTS

The prevalence of GBV-C/HGV viraemia, anti-E2 and GBV-C/HGV exposure among residents of Masago was significantly higher than that among donors (17.0%, 25.5% and 39.5% vs. 3.3%, 7.5% and 10.3%, respectively; all P < 0.0001). In Masago, the prevalence of GBV-C/HGV exposure was significantly higher in residents exposed to HCV than in those without HCV exposure (45.8% vs. 24.1%;P< 0.005). Based on multivariate analyses, HCV viraemia was the only significant factor associated with elevated levels of alanine aminotransferase in Masago. Phylogenetic analysis showed all 34 GBV-C/HGV isolates from Masago clustered within genotype 3.

CONCLUSIONS

GBV-C/HGV was highly prevalent in Masago, an HCV/HBV-endemic community in Taiwan. HCV viraemia played the most important clinical hepatopathic role in the area. Infections with other hepatitis viruses did not influence the anti-E2 seroconversion from GBV-C/HGV infections.

Identification and characterization of a novel gene that is upregulated in leukaemia cells by nitric oxide

Nitric oxide (NO) inhibits growth and induces differentiation in acute myeloid leukaemia (AML) cells. To identify genes associated with these processes, we studied the effect of NO on AML gene expression using the technique of Representational Difference Analysis. Exposure of HL-60 cells to the NO donor DETA-NO for 24 h induced the expression of a novel gene that was named rno (regulated by nitric oxide). Treatment of HL-60 cells with dimethyl sulphoxide induced expression of rno, but treatment with Vitamin D3 or all-trans retinoic acid did not. Upregulation of rno by NO was cGMP independent. Northern blot analysis indicated that constitutive expression of the novel gene was limited to leucocytes. Three isoforms of rno were identified. An rno cDNA clone was obtained by screening a human leucocyte library. The nucleotide sequence of the open reading frame shared significant homology with that of the human ribonuclease/angiogenin inhibitor (RI). The predicted amino acid sequence indicated that, like RI, rno is leucine and cysteine rich and is comprised of a series of repetitive elements (leucine-rich repeats) that may mediate macromolecular interactions. Enhancement of expression of rno may be a component of the process by which differentiation and growth inhibition of leukaemia cells is induced by NO.

The dynamic range for gain control of NMDA receptor-mediated synaptic transmission at a single synapse

Although the level at which NMDA receptors (NMDARs) are activated can profoundly influence the direction and extent of long-term changes in synaptic strength, the probabilistic nature of quantal release at individual synapses makes it difficult to determine the dynamic operating range of NMDAR-mediated synaptic transmission. By continually driving glutamate release from a single high-fidelity auditory synapse with bursts of high-frequency stimuli, I show here that NMDAR-mediated EPSCs exhibited incremental summation in their amplitude and did not reach a plateau until six or seven consecutive stimuli into the train. An increase in the initial quantal output, by broadening presynaptic spikes with the potassium channel blocker tetraethylammonium (TEA, 0.2 mm), slightly increased the plateau amplitude at 200/300 Hz but shifted its peak temporally toward the earlier stimuli. These results suggest that the plateau amplitude in TEA reflects the activation of the entire population of synaptic NMDARs and hence the maximal gain of NMDAR-mediated synaptic transmission. This maximum was estimated to be 3.2-fold of the basal synaptic strength, giving a 31% occupancy of synaptic NMDARs by glutamate. Thus, synaptic NMDARs possess a broad dynamic range within which the activity-dependent control of synaptic strength and plasticity can potentially be tuned by the amount of Ca(2+) influx associated with different levels of NMDAR occupancy within the same synapse.

Incidence and associated factors of neutralizing anti-interferon antibodies among chronic hepatitis C patients treated with interferon in Taiwan

BACKGROUND

The administration of interferon (IFN) could be complicated by the development of neutralizing anti-interferon antibodies (NA). This study evaluates the frequency and associated factors of NA among chronic hepatitis C patients treated with different IFNs.

METHODS

Ninety-five chronic hepatitis C patients were randomized to be treated with recombinant IFN-alpha2a (n = 28), IFN-alpha2b (n = 39) or lymphoblastoid IFN-alpha1 (n = 28) given intramuscularly, 3-6 million units, thrice weekly for 24 weeks. Serum samples collected before, during and after the cessation of treatment were checked for NA.

RESULTS

Three patients were withdrawn from treatment. All patients were negative for NA before treatment and 13 (14%) patients developed neutralizing antibodies. Of the 26 patients treated with IFN-alpha2a, 6 (23.1%) developed NA. whereas NA were detected in only 6 (15.4%) of 39 and 1 (3.7%) of 27 patients treated with IFN-alpha2b and IFN-alphanl, respectively. Age, gender, HCV genotype, ALT level, IFN total dose and liver histology were not associated with the development of NA. By using multivariate logistic regression it was shown that pretreatment HCV RNA level and IFN preparation were the two major factors related to the production of NA. The response of treatment was related to pretreatment viremia but not to the presence of NA.

CONCLUSIONS

The frequency of development of NA among Taiwanese patients with chronic hepatitis C might be related to different IFN preparations and pretreatment HCV RNA level. The response of treatment was related to pretreatment HCV RNA level but not to the presence of NA.

Status and natural course of GB virus C/hepatitis G virus infection among high-risk groups and volunteer blood donors in Taiwan

BACKGROUND

Hemophilia, thalassemia and uremia patients are at risk of parenterally transmitted infectious agents. The status and nature of the course of GB virus C/hepatitis G virus (GBV-C/HGV) infection among these groups and blood donors in Taiwan was investigated.

METHODS

Serum GBV-C HGV-RNA and antibodies to GBV-C/HGV envelope-2-protein (anti-E2) were determined in 500 blood donors and in 44 hemophilia, 37 thalassemia and 85 uremia patients. Phylogenetic analysis was performed.

RESULTS

The prevalence of GBV-C/HGV-RNA and anti-E2, respectively, was 38.6 and 27.3% in hemophilia patients, 27.0 and 27.3% in thalassemia patients, 14.1 and 10.6% in uremia patients and 3.4 and 7.2% in blood donors. The prevalence of GBV-C HGV exposure was 59.1 and 51.4% in hemophilia and thalassemia patients, respectively, which was significantly higher than that for uremia patients (22.4%; P < 0.01) and blood donors (10.2%; P < 0.001). The anti-E2 seroconversion rate was 66.7% in blood donors and 47.4, 36.8 and 34.6% in thalassemia, uremia (P < 0.05 compared with blood donors) and hemophilia (P < 0.01 compared with blood donors) patients, respectively. Discrepancies in the prevalence of GBV-C HGV and hepatitis C virus infection were found among the three risk groups. Phylogenetic analysis showed that 51 of 56 GBV-C HGV isolates clustered in group 3; the remaining five were of group 2a. Twelve of 39 viremic patients in the risk groups cleared the virus during the 4 year follow-up period; seven developed concomitant anti-E2 reactivity.

CONCLUSIONS

GB virus C hepatitis G virus infection is epidemic among risk groups and GBV-C HGV group 3 is the major strain in Taiwan. In the risk groups, approximately 18% of infections resolve with concomitant anti-E2 seroconversion within 4 years.

The epidemiology of TT virus (TTV) infection in a hepatitis C and B virus hyperendemic area of southern Taiwan

TT virus (TTV) is a newly isolated DNA virus from the serum of a patient with posttransfusion hepatitis of unknown etiology in 1997. To evaluate the clinical and molecular characteristics of TT virus (TTV) in a hepatitis C virus (HCV) and B (HBV) hyperendemic area (Masago), 200 residents were enrolled in the study. The sera were tested for alanine aminotransferase (ALT), HCV RNA and GB virus C/Hepatitis G virus (HGV) RNA, TTV DNA, HBsAg, anti-HCV and antibodies to HGV E2-protein (anti-E2). TTV DNA was positive in 99 of the 200 sera with a prevalence rate of 49.5%. The prevalence of HBsAg, anti-HCV, HCV RNA, HGV RNA, anti-E2 and HGV exposure (defined as positive for serum HGV RNA and/or anti-E2) was 38.9%, 69.5%, 64.5%, 17.0%, 25.5% and 39.5%, respectively. Neither clinical nor virological factors were associated with TTV viremia. The rate of ALT abnormality was significantly elevated in HCV RNA-positive (34.9%) than -negative (7.0%) residents (p < 0.001). HCV viremia was the only factor significantly associated with ALT elevation by multiple logistic regression (odds ratio: 6.96; 95% C.I.: 2.60-18.7). We concluded that in this HCV/HBV hyperendemic area, the prevalence of TTV DNA was high. No significant clinical factor was observed to be associated with TTV infection. TTV infection is not related to abnormal ALT levels and ALT abnormality was mainly attributable to HCV but not TTV, HBV or HGV infection.

Economic evaluation of Safer Choices: a school-based human immunodeficiency virus, other sexually transmitted diseases, and pregnancy prevention program

OBJECTIVE

To evaluate the cost-effectiveness and cost benefit of Safer Choices, a school-based human immunodeficiency virus, other sexually transmitted diseases, and unintended pregnancy prevention intervention for high school students.

METHODS

The baseline cost-effectiveness and cost benefit were derived in 4 steps: (1) estimation of intervention costs; (2) adaptation of the Bernoulli model to translate increases in condom use into cases of human immunodeficiency virus and other sexually transmitted diseases averted, and development of a model to translate increases in contraceptive use into cases of pregnancy averted; (3) translation of cases averted into medical costs and social costs averted; and (4) calculation of the net benefit of the program. Multivariable sensitivity analysis was performed to determine the robustness of the base-case results.

RESULTS

Under base-case assumptions, at an intervention cost of $105,243, Safer Choices achieved a 15% increase in condom use and an 11% increase in contraceptive use within 1 year among 345 sexually active students. An estimated 0.12 cases of human immunodeficiency virus, 24.37 cases of chlamydia, 2.77 cases of gonorrhea, 5.86 cases of pelvic inflammatory disease, and 18.5 pregnancies were prevented. For every dollar invested in the program, $2.65 in total medical and social costs were saved. Results of most of the scenarios remained cost saving under a wide range of model variable estimates.

CONCLUSIONS

The Safer Choices program is cost-effective and cost saving in most scenarios considered. School-based prevention programs of this type warrant careful consideration by policy makers and program planners. Program cost data should be routinely collected in evaluations of adolescent prevention programs.

[Determination of the active components in Chinese herb Aloe vera L. var. chinensis (Haw.) Berger by capillary zone electrophoresis]

It has been proved that the Chinese herb Aloe vera L. var. chinensis (Haw.) Berger as well as its active components showed many important pharmacology activities. In order to find an easy and low-cost method to control the quality of the herb, a CZE method for the determination of the active components aloin and aloe-emodin in Aloe vera L. var. chinensis (Haw.) Berger was developed in this work. Under the buffer conditions of 24 mmol/L phosphate (pH 10.52), applied voltage of 15 kV and detector wavelength of 254 nm, baseline separation of the active compounds in Aloe vera L. var. chinensis (Haw.) Berger was achieved and the active components were quantitatively analyzed. The linear calibration equations of the two components are: Y= -0.140 + 57.2X (r = 0.997) for aloin and Y = -0.393 + 1.08 x 10(2) X (r = 0.999) for aloe-emodin respectively. In addition, the effects of buffer pH value and organic modifier on the migration behavior of the solutes were also investigated.

Transcription factor NF-kappaB signals antianoikic function of trefoil factor 3 on intestinal epithelial cells

Transcription factor NF-kappaB has both pro-apoptotic and anti-apoptotic properties depending on the cell type. Its role in the intestinal epithelial cell has not been well elucidated. Trefoil factor 3 (TFF3) is an anti-apoptotic peptide secreted by intestinal goblet cells. Here we show that TFF3 activated NF-kappaB p50/p65 heterodimer within 1 h in IEC-18 cells (a nontransformed rat intestinal epithelial cell line). Moreover, we found that TFF3-treated IEC-18 cells are resistant to anoikis, an anchorage-related apoptosis in epithelium. In addition, the stable expression of a mutant form of the endogenous NF-kappaB inhibitor (IkappaBalpha(mut)) in IEC-18 cells results in a significant attenuation of anti-anoikic effect of TFF3. Taken together, these data indicate that (1) TFF3 is an endogenous gastrointestinal peptide with anti-anoikic property; (2) TFF3 activates NF-kappaB in enterocytes; and (3) TFF3-induced resistance to anoikis in intestinal epithelial cells is mediated by a distinct signaling cascade linked to NF-kappaB. Furthermore, our study implicates NF-kappaB as an important regulator in survival pathway of intestinal epithelial cells.

TGF-beta 1 modulated the expression of alpha 5 beta 1 integrin and integrin-mediated signaling in human hepatocarcinoma cells

Integrins are a family of cell surface adhesion molecules which mediate cell adhesion and initiate signaling pathways that regulate cell spreading, migration, differentiation, and proliferation. TGF-beta is a multifunctional factor that induces a wide variety of cellular processes. In this study, we show that, TGF-beta 1 treatment enhanced the amount of alpha 5 beta 1 integrin on cell surface, the mRNA level of alpha 5 subunit, and subsequently stimulated cell adhesion onto a fibronectin (Fn) and laminin (Ln) matrix in SMMC-7721 cells. TGF-beta 1 could also promote cell migration. Furthermore, our results showed that TGF-beta1 treatment stimulated the tyrosine phosphorylation level of FAK, which can be activated by the ligation and clustering of integrins. PTEN can directly dephosphorylate FAK, and the results that TGF-beta 1 could down-regulate PTEN at protein level suggested that TGF-beta 1 might stimulate FAK phosphorylation through increasing integrin signaling and reducing dephosphorylation of FAK. These studies indicated that TGF-beta 1 and integrin-mediated signaling act synergistically to enhance cell adhesion and migration and affect downstream signaling molecules of hepatocarcinoma cells.