Keh-Sung Tsai

Hepatitis B Virus Infection in Children and Adolescents in a Hyperendemic Area: 15 Years after Mass Hepatitis B Vaccination

Hepatitis B virus (HBV) infection is an important cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma in many parts of the world, including Taiwan (1, 2). Up to 15% to 20% of the general population in Taiwan are chronic carriers of hepatitis B surface antigen (HBsAg) (3, 4). Most chronic carriage of HBV results from infection in early childhood, especially before 2 years of age (57). Taiwan launched the worlds first nationwide universal vaccination program in 1984 to prevent infection in the early years of life (8). In addition to decreasing the proportion of carriers and the prevalence of HBV infection in the current young generation (9), the universal vaccination program has also resulted in a decreased incidence of childhood hepatocellular carcinoma (10). To study the effect of this universal vaccination program, we conducted a series of prospective seroepidemiologic surveys in Chung-Cheng District, Taipei City, Taiwan. The first survey was conducted shortly before the mass vaccination program began in 1984 (6), followed by similar surveys in 1989 (11) and 1994 (12). We report findings that extend our follow-up observations to 199915 years after the start of the program. Methods National Vaccination Program The national program of universal HBV vaccination in Taiwan began on 1 July 1984 (8). At that time, only the newborn infants of mothers who were HBsAg carriers were vaccinated. The vaccination program was extended in June 1987 to include all newborn infants and in July 1987 to cover all children of preschool age. The program was further extended to school children, teenagers, and then adults from 1988 to 1990. Since 1991, the vaccination records of first-grade children have been checked, and children without a complete set of previous vaccinations have been given catch-up HBV vaccinations. Before July 1992, four doses of plasma-derived vaccine were administered in children before 1 week of age and again at 1, 2, and 12 months of age; after July 1992, three doses of recombinant (yeast-derived) vaccine were administered before 1 week and at 1 month and 6 months of age. Since 1984, newborns whose mothers test positive for hepatitis B e antigen (HBeAg) have also received hepatitis B immunoglobulin, 0.5 mL (100 IU), within 24 hours after birth. The vaccination program has been described in greater detail elsewhere (8, 12). We defined the vaccination coverage rate as the percentage of children receiving at least three doses of HBV vaccine. We assessed the vaccination histories of the studied population by examining their vaccination cards and by taking a history from their parents. We classified the vaccination status as unknown for persons with a missing vaccination card or a vague vaccination history. Participants From March 1999 to October 1999, serum samples were collected from 1916 children and adolescents from two groups: 1) 1357 apparently healthy persons younger than 15 years of age [721 male participants and 636 female participants], who were born after the launch of the universal vaccination program, and 2) 559 persons (297 male participants and 262 female participants) 15 to 20 years of age, who were born before universal vaccination. We recruited participants for the baseline and follow-up seroepidemiologic studies in Chung-Cheng District, Taipei City. In 1999, Chung-Cheng had a population of 165 388 citizens; 35 005 of the citizens were younger than 15 years of age, and 47 565 were younger than 20 years of age. From 1994 to 1999, the population was stable, with an average annual migration rate of less than 4.8%. The annual family income,

A Simple Tool to Identify Asian Women at Increased Risk of Osteoporosis

39 963 (in U.S. dollars), was the third highest among the 12 districts in Taipei (13). From 1985 through 1990, the HBsAg carrier rate among pregnant women14% (14)was similar to the national average (3, 4). The 1916 participants in our 1999 study consisted of 1) 157 children younger than 3 years of age enrolled from the Well-Baby Clinic of the National Taiwan University Hospital Department of Pediatrics and from two day care centers; 2) 232 children 3 to 6 years of age recruited from two kindergarten classes; 3) 763 children 7 to 12 years of age enrolled from one public elementary school; 4) 205 children and adolescents 12 to 15 years of age enrolled from one public junior high school; 5) 219 adolescents 15 to 18 years of age enrolled from one high school; and 6) 340 first-year undergraduate students at the National Taiwan University, 19 to 20 years of age. We recruited the child and adolescent participants through poster advertisements and by invitation from the health staff of the Department of Pediatrics, National Taiwan University Hospital. The university student participants and the parents of enrolled children gave written, informed consent and provided the vaccination history of the participant, according to his or her personal health booklet. (The booklet, which is used to record a persons vaccination history, is provided to the parents of all newborns by the Health Bureau of City Hall.) Serologic and Statistical Analyses We analyzed serum samples for HBsAg, HBsAg antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) by using enzyme immunoassay (Abbott Laboratories, North Chicago, Illinois). We examined between-group differences in frequency by using the chi-square test with Yates correction or the Fisher exact test, where appropriate. A P value less than 0.05 was considered significant. Data analyses were performed by using GraphPad Prism, version 3.00 (GraphPad Software, Inc., San Diego, California). Role of the Funding Source The funding source had no role in the collection, analysis, and interpretation of the data or in the decision to submit the paper for publication. Results In 1999, the vaccination coverage rate was greater than 90% among children younger than 8 years of age and 80% to 86% among children 8 to 15 years of age (Table). These figures might be underestimates because some of the participants, particularly in the older age group, had missing vaccination cards; in other cases (for 23 of the 541 children younger than 8 years of age and 63 of the 766 participants 8 to 15 years of age), the parents could not recall the vaccination history. Infants had a lower coverage rate than other age groups because some of them had not yet finished their vaccination schedule (Appendix Table). Table. Seroprevalence of Hepatitis B Surface Antigen and Its Antibody in Chung-Cheng District, Taipei City, Taiwan, in 1984, 1989, 1994, and 1999 The prevalence of HBsAg in children younger than 15 years of age, 0.7% (9 of 1357), was considerably lower than the rate of 7% (39 of 559) observed in participants older than 15 years of age, who were born before the universal vaccination program (P < 0.001). Of the 9 children who were born after the vaccination program was instituted and tested positive for HBsAg, only 1 had not received the scheduled vaccinations, and the mother of this child was also HBsAg positive. According to their vaccination cards, the 8 other participants had received at least three doses of the HBV vaccine, and the first dose had been given within 1 week of birth. Seven of these 8 participants had mothers who were HBsAg carriers, and the remaining participant was living with two grandparents who were HBsAg positive. All 9 participants tested positive for anti-HBc. Eight of these 9 HBsAg carriers had received the plasma-derived vaccine, and 1 had received the yeast-derived recombinant vaccine; however, type of vaccine did not affect the rate of HBsAg seropositivity (8 of 968 persons who received the plasma-derived vaccine were carriers vs. 1 of 389 who received the yeast-derived vaccine; P > 0.2, Fisher exact test). The overall prevalence of anti-HBs in persons younger than 15 years of age in 1999 was 75.8%. We observed the highest prevalence of anti-HBs in children younger than 5 years of age (Table). The longitudinal perspective of HBsAg carriers in cohorts 0 to 1 years of age is shown in the Figure. Figure. Longitudinal perspective of the proportion of hepatitis B surface antigen carriers among the cohorts of 0 to 1 year of age in 1984 (circles) and 1989 (squares) in Chung-Cheng District, Taipei City, Taiwan. Children in the 1984 0- to 1-year age cohort, who were born before universal vaccination in Taiwan, had a carrier rate of 5.1% in 1984, 3.9% in 1989 (at age 5 to 6 years), 4.7% in 1994 (at age 10 to 11 years), and 7.5% in 1999 (at age 15 to 16 years). These proportions are significantly higher than those observed over time in the 1989 0- to 1-year age cohort, who were born since the national vaccination program started, at the corresponding age points (from the survey years 1989, 1994, and 1999, respectively). The rate of anti-HBc seropositivity was 2.9% in persons younger than 15 years of age but was 20.6% in persons 15 years of age or older (P < 0.001). In contrast, the rate of anti-HBc seropositivity among children younger than 15 years of age was 26.2% in 1984 (6), 14.5% in 1989 (11), and 4.0% in 1994 (12). Discussion The prevalence of HBsAg among children younger than 15 years of age decreased from 9.8% to 0.7% in the 15 years since implementation of the universal vaccination program. A high coverage rate for HBV vaccination is crucial for decreasing the prevalence of HBV infection. We observed a vaccination rate of at least 80% among children younger than 15 years of age and as high as 97% among children 4 years of age or younger. A nationwide series of seroepidemiologic studies of three cohorts of children 6 years of age in 1989, 1991, and 1993 reported that the vaccination rates for HBV ( 3 doses of vaccine) were 27.8%, 60.7%, and 88.7%, respectively (9). The age of these three cohorts in 1999 correspond to the age groups of 15 to 18 years, 13 to 14 years, and 11 to 12 years in our study. The data from these three national cohort studies confirm that the vaccination rate in our sample is similar to the vac

Impaired vitamin D metabolism with aging in women. Possible role in pathogenesis of senile osteoporosis.

Abstract. Patients with low bone mineral density (BMD) have a high risk of future fractures, and should be actively considered for treatment to reduce their risk. However, BMD measurements are not widely available in some communities, because of cost and lack of equipment. Simple questionnaires have been designed to help target high-risk women for BMD measurements, thereby avoiding the cost of measuring women at low risk. However, such tools have previously focused on evaluation of non-Asian women. We collected information about numerous risk factors from postmenopausal Asian women in eight countries in Asia using questionnaires, and evaluated the ability of these risk factors to identify women with osteoporosis as defined by femoral neck BMD T-scores ≤–2.5. Multiple variable regression analysis and item reduction yielded a final tool based on only age and body weight. This risk index had a sensitivity of 91% and specificity of 45%, with an area under the curve of 0.79. Previously published risk indices based on larger numbers of variables performed similarly well in this Asian population. Large differences in risk were identified using our index to create three categories: 61% of the high-risk women had osteoporosis, compared with only 15% and 3% of the intermediate- and low-risk women, respectively. The low-risk group represented 40% of all women, for whom BMD measurements are probably not needed unless important risk factors, such as prior nonviolent fracture or corticosteroid use, are present. An existing population-based sample of postmenopausal Japanese women was used to validate our index. In this sample of Japanese women the sensitivity was 98% and specificity was 29%; the low-risk category, for whom BMD is probably unnecessary, represented 25% of all women. We conclude that our index performed well for classifying the risk of osteoporosis among postmenopausal Asian women and applying it would result in more prudent use of BMD technology.

Acetylation of Yeast AMPK Controls Intrinsic Aging Independently of Caloric Restriction

Calcium absorption decreases with aging, particularly after age 70 yr. We investigated the possibility that this was due to abnormal vitamin D metabolism by studying 10 normal premenopausal women (group A), 8 normal postmenopausal women within 20 yr of menopause (group B), 10 normal elderly women (group C), and 8 elderly women with hip fracture (group D) whose ages (mean +/- SD) were 37 +/- 4, 61 +/- 6, 78 +/- 4, and 78 +/- 4 yr, respectively. For all subjects, serum 25-hydroxyvitamin D [25(OH)D] did not decrease with age, but serum 1,25-dihydroxyvitamin D [1,25(OH)2D], the physiologically active vitamin D metabolite, was lower (P = 0.01) in the elderly (groups C and D; 20 +/- 3 pg/ml) than in the nonelderly (groups A and B; 35 +/- 4 pg/ml). The increase of serum 1,25(OH)D after a 24-h infusion of bovine parathyroid hormone fragment 1-34, a tropic agent for the enzyme 25(OH)D 1 alpha-hydroxylase, correlated inversely with age (r = -0.58; P less than 0.001) and directly with glomerular filtration rate (r = 0.64; P less than 0.001). The response was more blunted (P = 0.01) in elderly patients with hip fracture (13 +/- 3 pg/ml) than in elderly controls (25 +/- 3 pg/ml). We conclude that an impaired ability of the aging kidney to synthesize 1,25(OH)2D could contribute to the pathogenesis of senile osteoporosis.

The Role of Phosphoinositide 3-Kinase/Akt Signaling in Low-Dose Mercury–Induced Mouse Pancreatic β-Cell Dysfunction In Vitro and In Vivo

Acetylation of histone and nonhistone proteins is an important posttranslational modification affecting many cellular processes. Here, we report that NuA4 acetylation of Sip2, a regulatory β subunit of the Snf1 complex (yeast AMP-activated protein kinase), decreases as cells age. Sip2 acetylation, controlled by antagonizing NuA4 acetyltransferase and Rpd3 deacetylase, enhances interaction with Snf1, the catalytic subunit of Snf1 complex. Sip2-Snf1 interaction inhibits Snf1 activity, thus decreasing phosphorylation of a downstream target, Sch9 (homolog of Akt/S6K), and ultimately leading to slower growth but extended replicative life span. Sip2 acetylation mimetics are more resistant to oxidative stress. We further demonstrate that the anti-aging effect of Sip2 acetylation is independent of extrinsic nutrient availability and TORC1 activity. We propose a protein acetylation-phosphorylation cascade that regulates Sch9 activity, controls intrinsic aging, and extends replicative life span in yeast.

Vitamin D inadequacy in postmenopausal women in Eastern Asia

The relationship between oxidation stress and phosphoinositide 3-kinase (PI3K) signaling in pancreatic β-cell dysfunction remains unclear. Mercury is a well-known toxic metal that induces oxidative stress. Submicromolar-concentration HgCl2 or methylmercury triggered reactive oxygen species (ROS) production and decreased insulin secretion in β-cell–derived HIT-T15 cells and isolated mouse islets. Mercury increased PI3K activity and its downstream effector Akt phosphorylation. Antioxidant N-acetyl-l-cysteine (NAC) prevented mercury-induced insulin secretion inhibition and Akt phosphorylation but not increased PI3K activity. Inhibition of PI3K/Akt activity with PI3K inhibitor or by expressing the dominant-negative p85 or Akt prevented mercury-induced insulin secretion inhibition but not ROS production. These results indicate that both PI3K and ROS independently regulated Akt signaling–related, mercury-induced insulin secretion inhibition. We next observed that 2- or 4-week oral exposure to low-dose mercury to mice significantly caused the decrease in plasma insulin and displayed the elevation of blood glucose and plasma lipid peroxidation and glucose intolerance. Akt phosphorylation was shown in islets isolated from mercury-exposed mice. NAC effectively antagonized mercury-induced responses. Mercury-induced in vivo effects and increased blood mercury were reversed after mercury exposure was terminated. These results demonstrate that low-dose mercury–induced oxidative stress and PI3K activation cause Akt signaling–related pancreatic β-cell dysfunction.

Body-Mass Index and Progression of Hepatitis B: A Population-Based Cohort Study in Men

ABSTRACT Objective: To review data on the prevalence of vitamin D inadequacy and its causes in postmenopausal women in Eastern Asia. Research design and method: Data were obtained from the published biomedical literature as well as abstracts and posters presented at scientific meetings. Using MEDLINE, EMBASE and BIOSIS databases (to July 2007), epidemiological studies were identified using the search terms: ‘human’, ‘vitamin D’, ‘vitamin D deficiency’, ‘vitamin D inadequacy’, ‘vitamin D insufficiency’ and ‘hypovitaminosis D’, ‘osteomalacia’ and ‘osteoporosis’. Additional references were also identified from the bibliographies of published articles. Results: The prevalence of vitamin D inadequacy in studies of postmenopausal women (ambulatory or with osteoporosis or related musculoskeletal disorders) in Eastern Asia ranged from 0 to 92%, depending on the cut-off level of serum 25-hydroxycholecalciferol [25(OH)D] that was applied (range ≤6–35 ng/mL [≤15–87 nmol/L]). One large international study found that 71% of postmenopausal women with osteoporosis in Eastern Asia had vitamin D inadequacy, defined as serum levels of 25(OH)D <30 ng/mL (75 nmol/L). Prevalence rates using this cut-off level were 47% in Thailand, 49% in Malaysia, 90% in Japan and 92% in South Korea. High prevalences of vitamin D inadequacy were evident in two studies using a lower 25(OH)D level cut-off value of <12 ng/mL(30 nmol/L) – 21% in China and 57% in South Korea. Dietary deficiency and inadequate exposure or reactivity to sunlight (due to lifestyle choices, cultural customs and/or aging) were identified as important risk factors for vitamin D inadequacy. Conclusions: Non-uniform, epidemiological studies indicate a high prevalence of vitamin D inadequacy in postmenopausal women in Eastern Asia. Recommended remedial approaches are education campaigns and broad-based provision of vitamin D supplementation.

Effectiveness and Limitations of Hand Hygiene Promotion on Decreasing Healthcare–Associated Infections

PURPOSE To determine prospectively whether body-mass index (BMI) is associated with liver-related morbidity and mortality among male hepatitis B virus (HBV) carriers. PATIENTS AND METHODS We performed a prospective study of 2,903 male HBV surface antigen-positive government employees who were free of cancer at enrollment between 1989 and 1992. Main outcome measures included ultrasonography, biochemical tests, incident hepatocellular carcinoma (HCC), and liver-related death. RESULTS During mean follow-up of 14.7 years, 134 developed HCC and 92 died as a result of liver-related causes. In Cox proportional hazards models adjusting for age, number of visits, diabetes, and use of alcohol and tobacco, the hazard ratios for incident HCC were 1.48 (95% CI, 1.04 to 2.12) in overweight men (BMI between 25.0 and 29.9 kg/m(2)) and 1.96 (95% CI, 0.72 to 5.38) in obese men (BMI >or= 30.0 kg/m(2)), compared with normal-weight men (BMI between 18.5 and 24.9 kg/m(2)). Liver-related mortality had adjusted hazard ratios of 1.74 (95% CI, 1.15 to 2.65) in overweight men and 1.50 (95% CI, 0.36 to 6.19) in obese men. Excess BMI was also associated with the occurrence of fatty liver and cirrhosis detected by ultrasonography, as well as elevated ALT and gamma-glutamyltransferase (GGT) activity during follow-up. The association of BMI with GGT was stronger than with ALT, and elevated GGT activity and cirrhosis were the strongest predictors for incident HCC and liver-related death. CONCLUSION This longitudinal cohort study indicates that excess body weight is involved in the transition from healthy HBV carrier state to HCC and liver-related death among men.

Prevalence of vertebral fractures in chinese men and women in urban Taiwanese communities.

Background Limited data describe the sustained impact of hand hygiene programs (HHPs) implemented in teaching hospitals, where the burden of healthcare-associated infections (HAIs) is high. We use a quasi-experimental, before and after, study design with prospective hospital-wide surveillance of HAIs to assess the cost effectiveness of HHPs. Methods and Findings A 4-year hospital-wide HHP, with particular emphasis on using an alcohol-based hand rub, was implemented in April 2004 at a 2,200-bed teaching hospital in Taiwan. Compliance was measured by direct observation and the use of hand rub products. Poisson regression analyses were employed to evaluate the densities and trends of HAIs during the preintervention (January 1999 to March 2004) and intervention (April 2004 to December 2007) periods. The economic impact was estimated based on a case-control study in Taiwan. We observed 8,420 opportunities for hand hygiene during the study period. Compliance improved from 43.3% in April 2004 to 95.6% in 2007 (p<.001), and was closely correlated with increased consumption of the alcohol-based hand rub (r = 0.9399). The disease severity score (Charlson comorbidity index) increased (p = .002) during the intervention period. Nevertheless, we observed an 8.9% decrease in HAIs and a decline in the occurrence of bloodstream, methicillin-resistant Staphylococcus aureus, extensively drug-resistant Acinetobacter baumannii, and intensive care unit infections. The intervention had no discernable impact on HAI rates in the hematology/oncology wards. The net benefit of the HHP was US

The effects of apolipoprotein E polymorphism on the distribution of lipids and lipoproteins in the Chinese population

5,289,364, and the benefit-cost ratio was 23.7 with a 3% discount rate. Conclusions Implementation of a HHP reduces preventable HAIs and is cost effective.