Biomedical subjects

Chuhsing Kate Hsiao

Publications and source records attributed to Chuhsing Kate Hsiao.

9 recordsLinked to original sources

PubMed2006

The association of single nucleotide polymorphisms in the 5'-regulatory region of the lumican gene with susceptibility to high myopia in Taiwan.

PURPOSE: To study the relationships between single nucleotide polymorphisms (SNPs) of lumican, decorin, and DSPG3 genes and high myopia. METHODS: One hundred and twenty adult patients with high myopia (< -10.0 D) and 137 controls were used to study the relationships between the decorin, lumican, and DSPG genes and high myopia. All subjects were free of ocular diseases, other than myopia, as well as of other systemic genetic diseases. Genotyping was performed by direct sequencing after PCR amplification of chromosomal DNA. Allele frequencies were tested for Hardy-Weinberg disequilibrium. The chi(2) or Fisher test was conducted to investigate the genotypic and allelic distribution between the high myopia and control groups. RESULTS: The genotyping success rate was 100%. Univariate analysis revealed significant differences between patients and control subjects with respect to one of the SNPs (rs3759223, C->T) of the lumican gene, with a p value of 0.000283. There was no significant relationship between other SNPs of lumican, decorin, and DSPG genes and high myopia. CONCLUSIONS: Our results indicate that an SNP (rs3759223), which is located in the promoter region of the lumican gene, may be worth further investigation to determine its association with development of high myopia.

5' Flanking Region↗

PubMed2006

Low sex hormone-binding globulin is associated with low high-density lipoprotein cholesterol and metabolic syndrome in women with PCOS.

BACKGROUND: Decreased high-density lipoprotein cholesterol (HDL-C) and sex hormone-binding globulin (SHBG) levels, and the metabolic syndrome, are all closely associated with a higher prevalence of atherosclerotic cardiovascular disease. We investigated the association between HDL-C, SHBG and the metabolic syndrome in women with polycystic ovary syndrome (PCOS). METHODS AND RESULTS: Among 106 young Taiwanese women (mean age +/- SD, 24.9 +/- 4.8 years) with PCOS, 69 (65.1%) women had an HDL-C level <50 mg dl(-1). The level of HDL-C was highly correlated with that of serum SHBG (gamma = 0.6034, P < 0.0001). The SHBG level was significantly lower in subjects with an HDL-C <50 mg dl(-1) than that in subjects with an HDL-C > or =50 mg dl(-1). Using multiple linear regression models with adjustment for age, BMI and other anthropometric, metabolic, liver function and hormonal variables, we showed serum SHBG to be independently correlated with HDL-C. Based on logistic regression analysis with adjustment for age, the SHBG level was significantly lower in women with PCOS with the metabolic syndrome (odds ratio = 0.92, P = 0.003). CONCLUSIONS: Low levels of SHBG in women with PCOS were associated with low levels of HDL-C, independent of insulin resistance and obesity. The SHBG level was inversely related to the occurrence of metabolic syndrome, further strengthening the potential link between SHBG levels and cardiovascular disease in women with PCOS.

Adolescent↗

PubMed2006

A two-stage design for multiple testing in large-scale association studies.

Modern association studies often involve a large number of markers and hence may encounter the problem of testing multiple hypotheses. Traditional procedures are usually over-conservative and with low power to detect mild genetic effects. From the design perspective, we propose a two-stage selection procedure to address this concern. Our main principle is to reduce the total number of tests by removing clearly unassociated markers in the first-stage test. Next, conditional on the findings of the first stage, which uses a less stringent nominal level, a more conservative test is conducted in the second stage using the augmented data and the data from the first stage. Previous studies have suggested using independent samples to avoid inflated errors. However, we found that, after accounting for the dependence between these two samples, the true discovery rate increases substantially. In addition, the cost of genotyping can be greatly reduced via this approach. Results from a study of hypertriglyceridemia and simulations suggest the two-stage method has a higher overall true positive rate (TPR) with a controlled overall false positive rate (FPR) when compared with single-stage approaches. We also report the analytical form of its overall FPR, which may be useful in guiding study design to achieve a high TPR while retaining the desired FPR.

Cost-Benefit Analysis↗

PubMed2006

Employment experience in relation to alcohol, tobacco, and betel nut use among youth in Taiwan.

The aim of this study is to assess the association linking employment experience with alcohol, tobacco, and betel nut involvement among youth in Taiwan. In 2004, an outreach program was conducted during weekdays to recruit youth sample in seven major geographic regions. A total of 5886 youth aged 12-18 years drawn from 26 cities or towns were assessed by a two-page anonymous self-administered questionnaire, including sociodemographic characteristics, employment-, development-, and drug-related experiences. In Taiwan, youthful experience of alcohol, tobacco, and polydrug use varies by employment status, work intensity, and job type. Holding a full-time job and working in certain settings (e.g., grocery, restaurants) were found associated with an excess of drug-using behaviors. With taking age, male gender, family context, disposable allowance, and school attendance into account, working youths were two to four times as likely to have recent drug involvement than their non-working counterparts, especially for tobacco and polydrug (OR=3.32, 95% CI: 2.58-4.27, p<0.001; OR=3.76, 95% CI: 2.76-5.13, p<0.001). Youths in the labor force emerge as a subgroup experiencing greater use of alcohol, tobacco, betel nut, and polydrug. Future prevention programs may target this high-risk group to reduce possible drug-related negative consequences in developmental and health domains in Taiwan.

Adolescent↗

PubMed2005

Regression-based association analysis with clustered haplotypes through use of genotypes.

Haplotype-based association analysis has been recognized as a tool with high resolution and potentially great power for identifying modest etiological effects of genes. However, in practice, its efficacy has not been as successfully reproduced as expected in theory. One primary cause is that such analysis tends to require a large number of parameters to capture the abundant haplotype varieties, and many of those are expended on rare haplotypes for which studies would have insufficient power to detect association even if it existed. To concentrate statistical power on more-relevant inferences, in this study, we developed a regression-based approach using clustered haplotypes to assess haplotype-phenotype association. Specifically, we generalized the probabilistic clustering methods of Tzeng to the generalized linear model (GLM) framework established by Schaid et al. The proposed method uses unphased genotypes and incorporates both phase uncertainty and clustering uncertainty. Its GLM framework allows adjustment of covariates and can model qualitative and quantitative traits. It can also evaluate the overall haplotype association or the individual haplotype effects. We applied the proposed approach to study the association between hypertriglyceridemia and the apolipoprotein A5 gene. Through simulation studies, we assessed the performance of the proposed approach and demonstrate its validity and power in testing for haplotype-trait association.

Apolipoprotein A-V↗

PubMed2005

Inference of nested variance components in a longitudinal myopia intervention trial.

This paper was motivated by a double-blind randomized clinical trial of myopia intervention. In addition to the primary goal of comparing treatment effects, we are concerned with the modelling of correlation that may come from two possible sources, one among the longitudinal observations and the other between measurements taken from both eyes per subject. The data are nested repeated measurements. We suggest three models for analysis. Each one expresses the correlation differently in various covariance structures. We articulate their differences and describe the implementations in estimation using commercial statistical software. The computer output can be further utilized to perform model selection with Schwarz criterion. Simulation studies are conducted to evaluate the performance under each model. Data of the myopia intervention trial are reanalysed with these models for illustration. The results indicate that atropine is more effective in reducing the progression rate, the rates are homogeneous across subjects, and, among the suggested models, the one with independent random effects of two eyes fits best. We conclude that model selection is a crucial step before making inference with estimates; otherwise the correlation may be attributed incorrectly to a different mechanism. The same conclusion applies to other variance components as well.

Analysis of Variance↗

PubMed2005

Bayesian tests of extra-Binomial variability.

A simple model for extra-Binomial variability is the Beta-Binomial. A complication in testing the Binomial against the Beta-Binomial alternative is that the Binomial lies on the boundary of the Beta-Binomial, which forces modifications to the usual asymptotic arguments. In this paper, we propose a Bayesian test using a pair of approximate Bayes factors, one for the case in which the maximum likelihood estimator (MLE) of the extra-Binomial variability is zero and one for the case in which it is positive. These approximate Bayes factors are easy to compute. We evaluate the operating characteristics of the Bayes factors and find them to be more powerful than the likelihood ratio test. We then apply the method to three data sets, including one in which the issue is whether a logistic regression intercept should be considered a random effect. In each case, our approximate Bayes factors are close to the exact Bayes factors, which may also be computed with additional effort.

Amputation, Surgical↗

PubMed2005

Survey of substance use among high school students in Taipei: web-based questionnaire versus paper-and-pencil questionnaire.

PURPOSE: To evaluate, using a randomized trial, whether a web-based self-administered questionnaire (web SAQ) can improve the reporting rate of substance use in adolescents compared with a paper-and-pencil self-administered questionnaire (paper SAQ). METHODS: Students of junior high, senior high, and vocational high schools in Taipei City and County were selected by a stratified, two-stage, probability proportional to size, random sampling. For each class selected, half of the students were randomly assigned to paper SAQ (n = 990) and the other half to web SAQ (n = 928). The inverse of the sampling probability for each individual was then used as sampling weight in the estimation of prevalence and logistic regression analysis. RESULTS: For readily available substances, the lifetime prevalence in the web SAQ group was significantly higher for alcohol use and borderline higher for tobacco and betel nut use compared to those of the paper SAQ group. For illicit drug use, the lifetime prevalence for the web SAQ group was significantly higher for the use of amphetamines, and borderline higher for ketamine. In multiple logistic regression analysis, the differences between the two groups in the use of alcohol, tobacco, and amphetamines remained significant. Boys, as well as both junior-high and vocational high school students who responded using the web SAQ, were more likely to report alcohol or tobacco use than those using the paper SAQ. CONCLUSIONS: Web SAQ leads to higher reporting rates of commonly used substances in adolescents compared with those of paper SAQ.

Adolescent↗

PubMed2003

Technical quality of root canal treatment in Taiwan.

AIM: To evaluate the current technical quality of root canal treatment (RCT) in Taiwan. METHODOLOGY: A total of 1085 RCT cases, randomly selected from a large sample and representative of the Taiwanese population from April to September 2000, were evaluated by eight endodontic specialists. The qualitative evaluation of RCT cases was based on two variables: length of the root filling and density of the obturation. A root canal with both adequate filling length (the apical termination of the root filling within 2 mm of the radiographic apex) and complete obturation (no lateral or apical canal lumen visible in the apical one-third of the root canal) was defined as having good-quality endodontic work (GQEW). A tooth was defined as having a GQEW when all its canals were categorized as GQEW. RESULTS: From a total of 1867 root canals, overfilling occurred in 235 (12.6%), adequate filling length in 1152 (61.7%), underfilling in 466 (25.0%) and no filling in 12 (0.6%). Of the 1867 root canals, 710 (38.0%) demonstrated complete obturation and 1157 (62%) demonstrated incomplete obturation. GQEW was found in 650 (34.8%) root canals and 329 (30.3%) teeth. The percentage of teeth with GQEW in hospital cases (38.1%) was significantly greater (P < 0.001) than that in private clinic cases (24.3%). In addition, the frequency of teeth with GQEW in the anterior teeth (40.4%) or in the premolars (33%) was significantly greater (P < 0.001) than that in the molars (18.4%). CONCLUSIONS: Approximately 70% of the teeth receiving RCT in Taiwan were either of inadequate filling length or sealing density.

Bicuspid↗