The Taiwan Birth Panel Study: a prospective cohort study for environmentally- related child health

<p>Abstract</p> <p>Background</p> <p>The Taiwan Birth Panel Study (TBPS) is a prospective follow-up study to investigate the development of child health and disease in relation to in-utero and/or early childhood environmental exposures. The rationale behind the establishment of such a cohort includes the magnitude of potential environmental exposures, the timing of exposure window, fatal and children's susceptibility to toxicants, early exposure delayed effects, and low-level or unknown neurodevelopmental toxicants.</p> <p>Methods</p> <p>A total of 486 mother-infant paired was enrolled from April 2004 to January 2005 in this study. Maternal blood before delivery, placenta and umbilical cord blood at birth, and mothers' urine after delivery were collected. The follow-up was scheduled at birth, 4, 6 months, and 1, 2, 3 and 5 years. The children's blood, urine, hair, and saliva were collected at 2 years of age and children's urine was collected at 5 years of age as well. The study has been approved by the ethical committee of National Taiwan University Hospital. All the subjects signed the inform consent on entering the study and each of the follow up.</p> <p>Results</p> <p>Through this prospective birth cohort, the main health outcomes were focused on child growth, neurodevelopment, behaviour problem and atopic diseases. We investigated the main prenatal and postnatal factors including smoking, heavy metals, perfluorinated chemicals, and non-persistent pesticides under the consideration of interaction of the environment and genes.</p> <p>Conclusions</p> <p>This cohort study bridges knowledge gaps and answers unsolved issues in the low-level, prenatal or postnatal, and multiple exposures, genetic effect modification, and the initiation and progression of "environmentally-related childhood diseases."</p

Second-hand smoke and chronic bronchitis in Taiwanese women: a health-care based study

<p>Abstract</p> <p>Background</p> <p>Cigarette smoking cannot fully explain the epidemiologic characteristics of chronic obstructive pulmonary disease (COPD) in women, particularly for those who rarely smoke, but COPD risk is not less than men. The aim of our study is to investigate the relationship between second-hand smoke (SHS) exposure and chronic bronchitis in Taiwanese women.</p> <p>Methods</p> <p>We used Taiwan's National Health Insurance Bureau claims data in 1999, and cross-checked using criteria set by the American Thoracic Society; there were 33 women with chronic bronchitis, 182 with probable chronic bronchitis, and 205 with no chronic bronchitis during our interview time between 2000 and 2005. We measured second-hand smoke (SHS) exposure by self-reported measures (household users and duration of exposure), and validated this by measuring urinary cotinine levels of a subset subjects. Classification of chronic bronchitis was also based on spirometry defined according to the GOLD guidelines to get the severity of COPD.</p> <p>Results</p> <p>Women who smoked and women who had been exposed to a lifetime of SHS were 24.81-fold (95% CI: 5.78-106.38) and 3.65-fold (95% CI: 1.19-11.26) more likely to have chronic bronchitis, respectively, than those who had not been exposed to SHS. In addition, there was a significant increasing trend between the severity of COPD and exposure years of SHS (<it>p </it>< 0.01). The population attributable risk percentages of chronic bronchitis for smokers and those exposed to SHS were 23.2 and 47.3% respectively.</p> <p>Conclusions</p> <p>These findings indicate that, besides cigarette smoking, exposure to SHS is a major risk factor for chronic bronchitis in Taiwanese women.</p

Transforming Growth Factor-β1 Suppresses Hepatitis B Virus Replication by the Reduction of Hepatocyte Nuclear Factor-4α Expression

Several studies have demonstrated that cytokine-mediated noncytopathic suppression of hepatitis B virus (HBV) replication may provide an alternative therapeutic strategy for the treatment of chronic hepatitis B infection. In our previous study, we showed that transforming growth factor-beta1 (TGF-β1) could effectively suppress HBV replication at physiological concentrations. Here, we provide more evidence that TGF-β1 specifically diminishes HBV core promoter activity, which subsequently results in a reduction in the level of viral pregenomic RNA (pgRNA), core protein (HBc), nucleocapsid, and consequently suppresses HBV replication. The hepatocyte nuclear factor 4alpha (HNF-4α) binding element(s) within the HBV core promoter region was characterized to be responsive for the inhibitory effect of TGF-β1 on HBV regulation. Furthermore, we found that TGF-β1 treatment significantly repressed HNF-4α expression at both mRNA and protein levels. We demonstrated that RNAi-mediated depletion of HNF-4α was sufficient to reduce HBc synthesis as TGF-β1 did. Prevention of HNF-4α degradation by treating with proteasome inhibitor MG132 also prevented the inhibitory effect of TGF-β1. Finally, we confirmed that HBV replication could be rescued by ectopic expression of HNF-4α in TGF-β1-treated cells. Our data clarify the mechanism by which TGF-β1 suppresses HBV replication, primarily through modulating the expression of HNF-4α gene

Spatial and Temporal Variations of Sampling Bioaerosols

Investigating microbiological contaminants in an environment is usually conducted by air sampling. Collection of representative samples in the environment may serve several functions, such as specification of species and sources, verification of control action, and accomplishment of the long-term goal to relate bioaerosol exposure to human health risk. However, the bioaerosol concentrations usually exhibit temporal, and spatial variations. These variations highly affect determination of representative samples in the environment. The study of temporal and spatial variations was conducted in three environments, two indoor sites within an office and laboratory research building and one outdoor adjacent site. The Andersen two-stage samplers were used to collect bacteria. A hot-film anemometer were used to measure air velocity in these two indoor sites. Bacterial samples were grown on TSA agar and incubated at 30°C for three days. The colony-formed units were counted. The counts were used to statistically study the relationship between the tested parameters (temperature, relative humidity,and air velocity) and the collected bacterial concentrations. Variations in bioaerosol concentrations were found to depend on the sampling environments, and variability was directly proportional to the distance between samplers, but variability was inversely proportional to air velocity.Master of Science in Environmental Engineerin

The Application of Mass Spectrometry in Molecular Dosimetry: Ethylene Oxide as an Example

Mass spectrometry plays an increasingly important role in the search for and quantification of novel chemically specific biomarkers. The revolutionary advances in mass spectrometry instrumentation and technology empower scientists to specifically analyze DNA and protein adducts, considered as molecular dosimeters, derived from reactions of a carcinogen or its active metabolites with DNA or protein. Analysis of the adducted DNA bases and proteins can elucidate the chemically reactive species of carcinogens in humans and can serve as risk-associated biomarkers for early prediction of cancer risk. In this article, we review and compare the specificity, sensitivity, resolution, and ease-of-use of mass spectrometry methods developed to analyze ethylene oxide (EO)-induced DNA and protein adducts, particularly N7-(2-hydroxyethyl)guanine (N7-HEG) and N-(2- hydroxyethyl)valine (HEV), in human samples and in animal tissues. GC/ECNCI-MS analysis after HPLC cleanup is the most sensitive method for quantification of N7-HEG, but limited by the tedious sample preparation procedures. Excellent sensitivity and specificity in analysis of N7-HEG can be achieved by LC/MS/MS analysis if the mobile phase, the inlet (split or splitless), and the collision energy are properly optimized. GC/ECNCI- HRMS and GC/ECNCI-MS/MS analysis of HEV achieves the best performance as compared with GC/ECNCI-MS and GC/EI-MS. In conclusion, future improvements in high- throughput capabilities, detection sensitivity, and resolution of mass spectrometry will attract more scientists to identify and/or quantify novel molecular dosimeters or profiles of these biomarkers in toxicological and/or epidemiological studies

Exposure Assessment of Airborne Acrylamide for Occupationally Exposed Workers by Using an Isotope-Dilution Gas Chromatography Coupled with Mass Spectrometry

Objectives: To develop a highly sensitive analytical method for very low acrylamide (AA) exposure and to conduct an occupational exposure assessment by the developed method. Methods: Seventy-five air samples from four plants were collected and analyzed using an isotope-dilution gas chromatography coupled with mass spectrometry (GC/MS). Results: This isotope-dilution GC MS method is sufficiently sensitive for assessing very low AA level as 4.37 ng m(-3), which is 10- to 7500-fold lower than the current analytical method. Field study showed that most airborne AA was gaseous rather than particulate. The personal exposure levels in workers ranged from 4.37 x 10(-3) m(-3) to 94.90 mu g m(-3) with a mean of 12.08 mu g m(-3). Fifty percent of personal 8 -h time-weighted average (TWA) concentrations in the AA production plant exceeded the threshold limit value of 30 mu g m(-3) set by American Conference of Governmental Industrial Hygienists. Conclusions: The field study indicated that 8-h TWA concentrations in workers varied by two orders of magnitude. The highly sensitive method can be used in future health risk assessment of AA exposure, such as those in fast-food restaurants