[Show abstract][Hide abstract] ABSTRACT: This study aimed to evaluate the practical utility of respondent-driven sampling (RDS) among regular tobacco and alcohol users in Taipei, Taiwan.
RDS was implemented from 2007 to 2010 to recruit seed individuals who were 18 to 50 years old, regular tobacco and alcohol users, and currently residing in Taipei. Each respondent was asked to refer up to five friends known to be regular tobacco smokers and alcohol drinkers to participate in the present study. Information pertaining to drug use was collected using an audio computer-assisted self-interview instrument. RDSAT software was used for data analyses.
The prevalence estimates of illegal-drug-using behaviors attained equilibrium after three to five recruitment waves. Nearly one-fifth of the participants had ever used illegal drugs, of whom over 60% were polydrug users. The RDS-adjusted prevalences of illegal-drug-using behaviors among early-onset smokers were all two or three times higher than those among late-onset smokers.
Our results provided an empirical basis for the practicality and feasibility of using RDS to estimate illegal drug use prevalence among regular tobacco and alcohol users.
Journal of Epidemiology 08/2015; DOI:10.2188/jea.JE20140229 · 2.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Inconsistent results of the molecular studies for handedness have been reported. One of the key issues involved could be ways of assessing handedness. The current study aimed to identify the index of handedness better reveal the genetic component, which showed higher heritability. We measured handedness using the Annett's handedness questionnaire. The college students participating in this study filled the questionnaire in the class while their first-degree relatives returned questionnaires one to two weeks later. A total of 1,968 subjects returned their questionnaires, including 640 college students and 1,328 first-degree relatives. Among the 449 college students returning at least one handedness questionnaire for their parents, a total of 449 fathers, 440 mothers, and 425 siblings participated in the study. The index of mixed-handedness (e.g., Degree of Handedness) showed highest heritability (0.67), followed by the Hand Preference Index (0.52), and then the Direction of Handedness (0.39). Using an index of mixed-handedness for future molecular studies was suggested.
[Show abstract][Hide abstract] ABSTRACT: The effects of peers on three domains of alcohol expectancies through early adolescence were prospectively examined over 2 years. Information on pubertal development, parental drinking, peer characteristics, network structure, alcohol expectancies, and alcohol consumption was assessed in a three-wave longitudinal study of 779 6th graders (~12years of age) randomly selected from northern Taiwan. Complex survey regression analyses, stratified by drinking experience in 6th grade, were performed to identify predictors of two positive (i.e., enhanced social behaviors and relaxation/tension reduction) and one negative alcohol expectancies (i.e., cognitive/behavioral deterioration) in 7th grade. The results showed that the effects of peer influence on adolescents' alcohol expectancies varied by prior drinking experiences and by expectancy domains. For the alcohol naive, recent exposure to peer drinking was significantly associated with positive and negative alcohol expectancies in grade 7, and this association was moderated by advanced pubertal development (ESBlate puberty: ßwt=0.55; ESBearly puberty: ßwt=-0.40; PRTRlate puberty: ßwt=0.01; PRTRearly puberty: ßwt=1.22; CBD late puberty: ßwt=-0.84; CBDearly puberty: ßwt=0.56). For the alcohol experienced, neither peer drinking nor pubertal development showed any significant links with alcohol expectancies. Occupying a bridge position was slightly linked with negative expectancy (ßwt=0.25). Concurrent drinking serves as a strong predictor for the endorsed alcohol expectancy in both groups, particularly for the domain of enhanced social behaviors. If these effects are confirmed, knowledge of the effect of interplay between peer factors and pubertal development on alcohol expectancies in early adolescence can provide effective targets in prevention programs.
[Show abstract][Hide abstract] ABSTRACT: This study examined the effects and mediators of a clinic-based intervention program (CBIP) and a home-based intervention program (HBIP) compared with usual care in very-low-birth-weight (VLBW) preterm infants on developmental and behavioral outcomes at 24 months of age (corrected for prematurity). In this randomized controlled trial, VLBW preterm infants received either CBIP (n=57), HBIP (n=63), or usual care (n=58) from hospitalization to 12 months. At 12 months, infant emotional regulation was assessed using the toy-behind-barrier procedure and dyadic interaction was observed during free play. At 24 months, infant developmental and behavioral outcomes were assessed using the Bayley Scales of Infant and Toddler Development- 3rd edition and the Child Behavior Checklist for Ages 1.5-5, respectively. Compared with infants under usual care, the CBIP-group infants showed higher cognitive composite scores (difference, 95% confidence interval (CI)=4.4, 0.8-7.9) and a lower rate of motor delay (odds ratio (OR), 95% CI=0.29, 0.08-0.99); the HBIP-group infants had lower sleep problem scores (difference, 95% CI=-1.4, -2.5 to -0.3) and a lower rate of internalizing problems at 24 months (OR, 95% CI=0.51, 0.28-0.93) (all p<.05). The CBIP's effect on cognitive outcome was attenuated when maternal or dyadic interactive behavior was considered; whereas the HBIP's effect on sleep and internalizing behavior was attenuated when duration of orientation to a toy or object was considered. In conclusions, interventions enhanced the cognitive, motor, and behavioral outcomes of VLBW preterm infants. The effects on cognitive and behavioral outcomes might be mediated by early-improved mother-infant interaction and infant emotional regulation, respectively.
Research in Developmental Disabilities 06/2014; 35(10):2384-2393. DOI:10.1016/j.ridd.2014.06.009 · 3.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Accumulating evidence suggests a role for microRNAs (miRNAs) in regulating various processes of mammalian postnatal development and aging. To investigate the changes in blood-based miRNA expression from preterm infants to adulthood, we compared 365 miRNA expression profiles in a screening set of preterm infants and adults. Approximately one-third of the miRNAs were constantly expressed from postnatal development to adulthood, another one-third were differentially expressed between preterm infants and adults, and the remaining one-third were not detectable in these two groups. Based on their expression in infants and adults, the miRNAs were categorized into five classes, and six of the seven miRNAs chosen from each class except one with age-constant expression were confirmed in a validation set containing infants, children, and adults. Comparing the chromosomal locations of the different miRNA classes revealed two hot spots: the miRNA cluster on 14q32.31 exhibited age-constant expression, and the one on 9q22.21 exhibited up-regulation in adults. Furthermore, six miRNAs detectable in adults were down-regulated in older adults, and four chosen for individual quantification were verified in the validation set. Analysis of the network functions revealed that differentially regulated miRNAs between infants and adults and miRNAs that decreased during aging shared two network functions: inflammatory disease and inflammatory response. Four expression patterns existed in the 11 miRNAs from infancy to adulthood, with a significant transition in ages 9–20 years. Our results provide an overview on the regulation pattern of blood miRNAs throughout life and the possible biological functions performed by different classes of miRNAs.
[Show abstract][Hide abstract] ABSTRACT: This study aimed to investigate the relations of adolescent sexual experiences (particularly early initiation) to a spectrum of emotional/behavioral problems and to probe possible gender difference in such relationships. The 10th (N = 8,842) and 12th (N = 10,083) grade students, aged 16-19 years, participating in national surveys in 2005 and 2006 in Taiwan were included for this study. A self-administered web-based questionnaire was designed to collect information on sociodemographic characteristics, sexual experience, substance use, and the Youth Self-Report Form. For the sexually experienced adolescents, their sexual initiation was classified as early initiation (<16 years) or non-early initiation (16-19 years). Gender-specific multivariate response profile regression was used to examine the relationship between sexual experience and the behavioral syndromes. Externalizing problems, including Rule-breaking Behavior and Aggressive Behavior, were strongly associated with sexual initiation in adolescence; the magnitude of the association increased for earlier sexual initiation, especially for females. As to internalizing problems, the connection was rather heterogeneous. The scores on some syndromes, such as Somatic Complaints and Anxious/Depressed, were higher only for females with early or non-early sexual initiation whereas the score on Withdrawn, along with Social Problems that is neither internalizing nor externalizing, was lower for the sexually experienced adolescents than for the sexually inexperienced ones. We concluded that earlier sexual initiation was associated with a wider range of behavioral problems in adolescents for both genders, yet the increased risk with emotional problems was predominately found in females.
Archives of Sexual Behavior 03/2014; 44(3). DOI:10.1007/s10508-014-0265-7 · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The popularity of ketamine for recreational use among young people began to increase, particularly in Asia, in 2000. To gain more knowledge about the use of ketamine among high risk individuals, a respondent-driven sampling (RDS) was implemented among regular alcohol and tobacco users in the Taipei metropolitan area from 2007 to 2010. The sampling was initiated in three different settings (i.e., two in the community and one in a clinic) to recruit seed individuals. Each participant was asked to refer one to five friends known to be regular tobacco smokers and alcohol drinkers to participate in the present study. Incentives were offered differentially upon the completion of an interview and successful referral. Information pertaining to drug use experience was collected by an audio computer-assisted self-interview instrument. Software built for RDS analyses was used for data analyses. Of the 1,115 subjects recruited, about 11.7% of the RDS respondents reported ever having used ketamine. Positive expectancy of ketamine use was positively associated with ketamine use; in contrast, negative expectancy inversely associated with ketamine use. Decision-making characteristics as measured on the Iowa Gambling Task using reinforcement learning models revealed that ketamine users learned less from the most recent event than both tobacco- and drug-naïve controls and regular tobacco and alcohol users. These findings about ketamine use among young people have implications for its prevention and intervention.
Journal of Food and Drug Analysis 12/2013; 21(4):S102-S105. DOI:10.1016/j.jfda.2013.09.044 · 0.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The copy number variation (CNV) is a type of genetic variation in the genome. It is measured based on signal intensity measures and can be assessed repeatedly to reduce the uncertainty in PCR-based typing. Studies have shown that CNVs may lead to phenotypic variation and modification of disease expression. Various challenges exist, however, in the exploration of CNV-disease association. Here we construct latent variables to infer the discrete CNV values and to estimate the probability of mutations. In addition, we propose to pool rare variants to increase the statistical power and we conduct family studies to mitigate the computational burden in determining the composition of CNVs on each chromosome. To explore in a stochastic sense the association between the collapsing CNV variants and disease status, we utilize a Bayesian hierarchical model incorporating the mutation parameters. This model assigns integers in a probabilistic sense to the quantitatively measured copy numbers, and is able to test simultaneously the association for all variants of interest in a regression framework. This integrative model can account for the uncertainty in copy number assignment and differentiate if the variation was de novo or inherited on the basis of posterior probabilities. For family studies, this model can accommodate the dependence within family members and among repeated CNV data. Moreover, the Mendelian rule can be assumed under this model and yet the genetic variation, including de novo and inherited variation, can still be included and quantified directly for each individual. Finally, simulation studies show that this model has high true positive and low false positive rates in the detection of de novo mutation.
Frontiers in Genetics 09/2013; 4:185. DOI:10.3389/fgene.2013.00185
[Show abstract][Hide abstract] ABSTRACT: An analysis for the quasi-steady electrophoretic motion of a soft particle composed of a charged spherical rigid core and an adsorbed porous layer positioned at the center of a charged spherical cavity filled with an arbitrary electrolyte solution is presented. Within the porous layer, frictional segments with fixed charges are assumed to distribute uniformly. Through the use of the linearized Poisson-Boltzmann equation and the Laplace equation, the equilibrium double-layer potential distribution and its perturbation caused by the applied electric field are separately determined. The modified Stokes and Brinkman equations governing the fluid flow fields outside and inside the porous layer, respectively, are solved subsequently. An explicit formula for the electrokinetic migration velocity of the soft particle in terms of the fixed charge densities on the rigid core surface, in the porous layer, and on the cavity wall is obtained from a balance between its electrostatic and hydrodynamic forces. This formula is valid for arbitrary values of , , , and , where is the Debye screening parameter, is the reciprocal of the length characterizing the extent of flow penetration inside the porous layer, is the radius of the soft particle, is the radius of the rigid core of the particle, and is the radius of the cavity. In the limiting cases of and , the migration velocity for the charged soft sphere reduces to that for a charged impermeable sphere and that for a charged porous sphere, respectively, in the charged cavity. The effect of the surface charge at the cavity wall on the particle migration can be significant and the particle may reverse the direction of its migration.
The Journal of Physical Chemistry B 07/2013; 117(33). DOI:10.1021/jp405357e · 3.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pneumonia is one of most prevalent infectious diseases worldwide and is associated with considerable mortality. In comparison to general population, schizophrenia patients hospitalized for pneumonia have poorer outcomes. We explored the risk factors of short-term mortality in this population because the information is lacking in the literature.
In a nationwide schizophrenia cohort, derived from the National Health Insurance Research Database in Taiwan, that was hospitalized for pneumonia between 2000 and 2008 (n = 1,741), we identified 141 subjects who died during their hospitalizations or shortly after their discharges. Based on risk-set sampling in a 1∶4 ratio, 468 matched controls were selected from the study cohort (i.e., schizophrenia cohort with pneumonia). Physical illnesses were categorized as pre-existing and incident illnesses that developed after pneumonia respectively. Exposures to medications were categorized by type, duration, and defined daily dose. We used stepwise conditional logistic regression to explore the risk factors for short-term mortality.
Pre-existing arrhythmia was associated with short-term mortality (adjusted risk ratio [RR] = 4.99, p<0.01). Several variables during hospitalization were associated with increased mortality risk, including incident arrhythmia (RR = 7.44, p<0.01), incident heart failure (RR = 5.49, p = 0.0183) and the use of hypoglycemic drugs (RR = 2.32, p<0.01). Furthermore, individual antipsychotic drugs (such as clozapine) known to induce pneumonia were not significantly associated with the risk.
Incident cardiac complications following pneumonia are associated with increased short-term mortality. These findings have broad implications for clinical intervention and future studies are needed to clarify the mechanisms of the risk factors.
PLoS ONE 07/2013; 8(7):e70142. DOI:10.1371/journal.pone.0070142 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: AimTo examine the association between alcohol in school environments and adolescent alcohol use over the previous 6 months. DesignA multi-level logistic regression analysis was performed of cross-sectional surveys conducted in 2004, 2005 and 2006. Participants and settingA total of 52214 students aged 11-19 years from 387 middle or high schools were selected from a nationally representative, multi-stage, stratified probability sampling across Taiwan. MeasurementsInformation on socio-demographic features and substance use experiences was collected using self-administered questionnaires. The alcohol in the environment was measured using the availability of convenience stores surrounding the schools. Using geographical information systems, the weighted numbers of convenience stores within 1km, a 12-15-minute walk, of a school were calculated. The schools were later categorized into three subgroups via the tertile of nearby convenience stores. FindingsConsidering the compositional characteristics, the availability of convenience stores was found to account for 1.5% of the school-level variance of youthful drinking. The odds ratios (95% confidence interval) of alcohol use over the previous 6 months among youth attending schools with medium and high availability were 1.04 (0.96-1.13) and 1.08 (1.00-1.17), respectively, with a P-value of 0.04 in the trend test. Conclusion
The greater availability of convenience stores near a school is associated with an increased risk of alcohol use among adolescents over the previous 6 months.
[Show abstract][Hide abstract] ABSTRACT: Background:Because environmental insults and genetic factors account for the variance in the risk of bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW; birth weight < 1,500 g) preterm infants, the search for BPD biomarkers has begun to focus on the regulators of non-coding RNA such as microRNAs (miRNAs). Therefore, this study aimed to identify potential miRNAs involved in the pathogenesis of BPD in VLBW preterm infants.Methods:A case-control study (15 BPD cases and 15 sex-matched controls) was conducted to investigate the expression profiles of 365 miRNAs in the peripheral blood of VLBW preterm infants at 36 weeks post-menstrual age (called the older-aged set). The expression levels of identified miRNAs were further evaluated in a subsample of blood collected during the first two weeks postnatal age (called the younger-aged set). Possible biological functions and pathways implicated in the target genes regulated by the miRNAs were explored using database predictions.Results:A four-miRNA signature (miR-152, miR-30a-3p, miR-133b and miR-7) with aberrant expression levels at 36 weeks derived from a supervised classification with internal cross-validation discriminated the BPD cases from the controls with an accuracy of 0.91. The discriminative accuracy of the four miRNAs was supported by random permutations of either the disease status or the number of miRNAs selected (both p < 0.0001). A down-regulation change of miR-152 and miR-30a-3p expression levels and an up-regulation change of miR-133b and miR-7 expression levels were found in the older-aged set compared to the younger-aged set.Conclusions:This is the first study to identify blood-based miRNAs associated with BPD. The findings provide information regarding the roles of these biomarkers in the development of BPD in VLBW preterm infants.
Respiratory care 03/2013; 58. DOI:10.4187/respcare.02166 · 1.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to examine the relationships of Doppler cerebral blood flow velocity (CBFV) asymmetry measures with developmental outcomes in term infants. Doppler CBFV parameters (peak systolic velocity [PSV] and mean velocity [MV]) of the bilateral middle cerebral arteries of 52 healthy term infants were prospectively examined on postnatal days 1-5, and then their motor, cognitive and language development was evaluated with the Bayley Scales of Infant and Toddler Development, Third Edition, at 6, 12, 18 and 24 months of age. The left CBFV asymmetry measure (PSV or MV) was calculated by subtracting the right-side value from the left-side value. Left CBFV asymmetry measures were significantly positively related to motor scores at 6 (r = 0.3-0.32, p < 0.05) and 12 (r = 0.35, p < 0.05) months of age, but were not related to cognitive or language outcome. Thus, the leftward hemodynamic status of the middle cerebral arteries, as measured by cranial Doppler ultrasound in the neonatal period, predicts early motor outcome in term infants.
Ultrasound in medicine & biology 02/2013; DOI:10.1016/j.ultrasmedbio.2012.12.012 · 2.10 Impact Factor