Search

Symptoms of schizophrenia (SZ) typically emerge during adolescence to young adulthood, which gives a window before full-blown psychosis for early intervention. Strategies for preventing the conversion from the prodromal phase to the psychotic phase are warranted. Heterozygous (Het) Disc1 mutant mice are considered a prodromal model of SZ, suitable for studying psychotic conversion. We evaluated the preventive effect of chronic N-acetylcysteine (NAC) administration, covering the prenatal era to adulthood, on the reaction following the Amph challenge, which mimics the outbreak or conversion of psychosis, in adult Het Disc1 mice. Biochemical and morphological features were examined in the striatum of NAC-treated mice. Chronic NAC treatment normalized the Amph-induced activity in the Het Disc1 mice. Furthermore, the striatal phenotypes of Het Disc1 mice were rescued by NAC including dopamine receptors, the expression of GSK3s, MSN dendritic impairments, and striatal PV density. The current study demonstrated a potent preventive effect of chronic NAC treatment in Disc1 Het mice on the acute Amph test, which mimics the outbreak of psychosis. Our findings not only support the benefit of NAC as a dietary supplement for SZ prodromes, but also advance our knowledge of striatal dopamine receptors, PV neurons, and GSK3 signaling pathways as therapeutic targets for treating or preventing the pathogenesis of mental disorders. [ABSTRACT FROM AUTHOR]

Occupational asbestos exposure was prevalent in Taiwan, but asbestos-related diseases (ARDs) have rarely been recognized. We conducted in-depth face-to-face interviews with 16 patients with ARDs. All of them had worked in industries known for high asbestos exposure. However, only three patients had filed workers' compensation (WC) claims, and of them, only two patients were approved. Reasons for the low compensation rate of ARDs could be divided into institutional barriers related to the flaws of the WC system and non-institutional barriers related to the knowledge status, causal interpretation, and social situations of individual workers. The Labor Occupational Accident Insurance and Protection Act passed in April 2021 has responded to the under-compensation of occupational diseases. However, the new act's effects toward improving the recognition of ARDs remain questionable. Our findings indicated that additional efforts are needed to remove non-institutional barriers hindering workers' ability to ensure their compensation rights. [ABSTRACT FROM AUTHOR]

Air pollutants are substances in the air that have harmful effects on humans and the ecological environment. Although slight elevations in carcinoembryonic antigen (CEA) are commonly observed in apparently healthy persons, potential associations between CEA levels and chronic low-grade inflammation induced by air pollution have yet to be documented. We conducted a community-based cross-sectional study to estimate the association between short-term exposure to ambient air pollution and the CEA. A total of 9728 participants from health examinations were enrolled for the analysis and linked with their residential air pollutant data including ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO), sulphur dioxide (SO2), and particulate matter (PM10). The results showed that every increase of 1 ppm O3 significantly increased the mean differences of the CEA blood concentration by 0.005 ng/mL. Each increase of 1 ppm CO significantly reduced the mean differences of the CEA blood concentration by 0.455 ng/mL. Although smoking and alcohol drinking also increased the CEA levels, with adjustment of these confounders we identified a significant association between serum CEA in the general population and levels of the air pollutants O3 and CO. In conclusion, the serum CEA concentrations and short-term air pollutants O3 and CO exposure were found to have a significant relationship; however, its mechanism is still unclear. Moreover, long-term air pollution exposure and changes in CEA concentration still need to be further evaluated. [ABSTRACT FROM AUTHOR]

Background: Malignant mesothelioma (MM) is rare and fatal; survival in most cases is only about one year. Mortality rate is, therefore, a good proxy measure of incidence rate. However, the specific International Classification of Diseases (ICD) code for MM was not available until the Tenth Revision ICD (ICD‐10). Little is known on which Ninth Revision ICD (ICD‐9) codes were assigned for MM in the ICD‐9 era. Methods: We used a 1996 double‐coded mortality file compiled by the National Center for Health Statistics to calculate the detection rate (DR) and confirmation rate (CR) of selected ICD‐9 codes. Results: Of 2386 decedents whose underlying cause of death was MM (ICD‐10 code C45), the DR (deaths) of corresponding ICD‐9 code was 57% (1365) for code 199 "malignant neoplasm without specification of site;" 19% (448) for code 162.9 "malignant neoplasm of trachea, bronchus, and lung, unspecified;" 13% (310) for code 163 "malignant neoplasm of pleura;" and 11% (271) for other codes. The CR (deaths) for the aforementioned three ICD‐9 codes were 4.0% (1365/33,942), 0.3% (448/150,342), and 70.8% (310/438), respectively. Conclusions: The three ICD‐9 codes (199, 162.9, and 163) were the most commonly used codes for MM and composed nine‐tenths of all MM deaths in the years before the ICD‐10 was introduced. Using only ICD‐9 code 163, the code most often used as the surrogate measure of MM in mortality studies in the ICD‐9 era, capture may have been only 13% of all MM deaths in the US, and the estimated number of MM deaths missed in 1996 would be 2086. [ABSTRACT FROM AUTHOR]

Sleep/circadian rhythm disturbances are environmental stress factors that might interact with genetic risk factors and contribute to the pathogenesis of psychiatric disorders. In this study, the multiple-platform method was used to induce sleep deprivation (SD). We evaluated the impact of 72-hour SD in behavioural, anatomical, and biochemical aspects in heterozygous Disc1 mutant (Disc1 Het) mice, an animal model of schizophrenia. The sleep pattern and circadian activity were not altered in Disc1 Het mice. Yet, we observed differential responses to SD stress between genotypes. Increased microglial density and reduced neuronal proliferative activity were found in the dentate gyrus, a neurogenic niche, in Het-SD mice. Notably, SD-induced Bdnf mRNA elevations were evident in both WT and Het mice, while only in WT-SD mice did we observe increased BDNF protein expression. Our results suggested an SD-induced physical response featured by the elevation of BDNF protein expression to counteract the harmful influences of SD and sufficient DISC1 is required in this process. The present study proposes that sleep disturbance could be pathogenic especially in genetically predisposed subjects who fail to cope with the stress. Potential therapeutic strategies for psychiatric disorders targeting the mRNA translation machinery could be considered. [ABSTRACT FROM AUTHOR]

Purpose: Malignant mesothelioma (MM) is associated with past exposure to asbestos and the latency period ranged from 20 to 40 years. Asbestos consumption reached a peak in the 1980s in Taiwan, and the MM mortality is expected to increase since 2000s. However, no specific code for MM was available before the International Classification of Disease, Tenth Revision (ICD-10), which was launched in 2008 in Taiwan. We examined how MM was coded in mortality data in Taiwan during the years when the ICD, Ninth Revision (ICD-9) was used. Patients and Methods: Double-coded mortality data (each death coded according to both ICD-10 and ICD-9 codes) for the period 2002– 2008 were obtained for analysis. Detection rates (similar to sensitivity) and confirmation rates (similar to positive predictive value) for various potential proxy ICD-9 codes for MM were calculated. Results: For 113 deaths, for which the underlying cause of death was ICD-10 code C45 (MM), 14 corresponding ICD-9 codes were used. Four ICD-9 codes constituted 77% (87/113) of all MM deaths. The detection rate for code 199 (malignant neoplasm [MN] without specification of site) was 37% (42/113), that for code 163 (MN of pleura) was 18% (20/113), that for code 162 (MN of trachea, bronchus, and lung) was 12% (14/113), and that for code 173 (other MN of skin) was 10% (11/113). The confirmation rates for codes 199, 163, 162, and 173 were 0.9% (42/4759), 14.3% (20/140), 0.03% (14/51,778), and 1.5% (11/717), respectively. Conclusion: ICD-9 codes 199, 163, 162, and 173 were most commonly used for MM deaths in Taiwan during the years before the ICD-10 introduction. However, when we used only ICD-9 code 163, which was most commonly used as a surrogate measure of MM in mortality studies during the ICD-9 era, we could detect only one-fifth of MM deaths in Taiwan. [ABSTRACT FROM AUTHOR]

Claims databases consisting of routinely collected longitudinal records of medical expenditures are increasingly utilized for estimating expected medical costs of patients with a specific condition. Survival data of the patients of interest are usually highly censored, and observed expenditures are incomplete. In this study, we propose a survival-adjusted estimator for estimating mean lifetime costs, which integrates the product of the survival function and the mean cost function over the lifetime horizon. The survival function is estimated by a new algorithm of rolling extrapolation, aided by external information of age- and sex-matched referents simulated from national vital statistics. The mean cost function is estimated by a weighted average of mean expenditures of patients in a number of months prior to their death, of which the number could be determined by observed costs in their final months, and the weights depend on extrapolated hazards. We evaluate the performance of the proposed approach in comparison with that of a popular method using simulated data under various scenarios and 2 cohorts of intracerebral hemorrhage and ischemic stroke patients with a maximum follow-up of 13 years and conclude that our new method estimates the mean lifetime costs more accurately. [ABSTRACT FROM AUTHOR]

Background/purpose: Globally, asbestos-related diseases (ARDs) keep rising over the coming decades. The epidemic of ARDs will be a burden on public health. We aimed to predict the malignant pleural mesothelioma (MPM) incidence in the next 30 years for Taiwan based on historical asbestos consumption.Methods: We collected annual data on local asbestos consumption during 1939-2015 and sex-specific incidence of pleural cancer as a proxy for MPM during 1979-2013. We applied Poisson log-linear models to predict future MPM numbers under the assumption that latency periods between asbestos exposure and MPM incidence were between 25 and 45 years.Results: Asbestos consumption reached a peak in the 1980s, with a total of 668 thousand metric tons during 1939-2015. The observed number of MPM incidence increased by 9- and 6-fold in males and females during 1979-2013, with a cumulative number of 907. Given a latency period of 31 years, MPM incidences were expected to peak around 2012-2016 for males and 2016-2020 for females. In 2017-2046, the predicted total number of new MPM might reach 659 cases (95% confidence interval = 579-749); and the male to female ratios ranged from 1.8 to 2.8.Conclusion: The MPM epidemic in Taiwan will likely peak in 2012-2020 as a result of local asbestos consumption. Approximately 659 new MPM cases in the next 30 years warrant an urgent need to implement a total asbestos ban and put more resources on a comprehensive surveillance, diagnosis, and follow-up health care system for ARDs. [ABSTRACT FROM AUTHOR]

Background/purpose: There are scarce reports on the prognostic factors and treatment outcomes of patients with malignant pleural mesothelioma (MPM) in Asia. This study aimed to address these matters in a real-world setting.Methods: Medical records of patients with histologically proven MPM diagnosed between 1977 and 2016 at the National Taiwan University Hospital were reviewed. Variables including age, gender, performance status, asbestos exposure, smoking history, histology subtype, staging, and treatment received were recorded. All patients were followed until death or March 1st, 2017. Survival and prognostic factors were analyzed by the Kaplan-Meir method and the Cox proportional hazard model.Results: A total of 93 patients was identified, including 65 men and 28 women. An increasing trend of MPM cases diagnosed was observed in the past 40 years. Stage I/II disease (HR 0.24, 95% CI 0.13-0.46) and epithelioid histology (HR 0.42, 95% CI 0.23-0.75) were associated with favorable prognosis, whereas age ≥70 years (HR 2.66, 95% CI 1.36-5.22) and ECOG ≥2 (HR 5.03, 95% CI 2.69-9.4) were poor prognostic factors. After adjustment for prognostic factors, surgery in stage I-III MPM (HR 0.36, 95% CI 0.15-0.83) and systemic therapy in stage III/IV disease (HR 0.42, 95% CI 0.19-0.94) conferred a survival benefit.Conclusion: This is one of the largest case series of MPM reported in Asia outside of Japan. Prognostic factors in the study population included age, performance status, stage, and histology subtype. Surgery in potentially resectable disease and systemic therapy in advanced MPM confer a survival benefit in Asian patients. [ABSTRACT FROM AUTHOR]

Background: Idiopathic Parkinson’s disease (IPD) is a progressive neurodegenerative disorder characterized by typical motor impairment. However, lower urinary tract symptoms, including urinary urgency or frequency, which are non-motor phenomena, occur frequently among patients with IPD. In this study, we assess the risk of overactive bladder (OAB) in patients with IPD. Methods: The National Health Insurance Research Database of Taiwan was used to identify patients with IPD (IPD cohort) and four-fold controls (non-IPD cohort) from 2000 to 2010. The non-IPD cohort was matched according to age, sex, and baseline comorbidities, including benign prostate hyperplasia, stress incontinence, diabetes, and cerebrovascular diseases. The occurrence of OAB was monitored until the end of 2011. Hazard ratios of OAB were estimated using Cox proportional hazards regression models. Results: In total, 4,571 and 18,255 patients were included in IPD and non-IPD cohorts, respectively. Results showed a significantly higher overall incidence rate of OAB in the IPD cohort compared with the non-IPD cohort (14.5 vs. 6.37 per 10,000 person-years), with a 2.3-fold increased risk of OAB (95% confidence interval [CI] = 1.51–3.51) after controlling for benign prostate hyperplasia and stress incontinence. The mean follow-up period for the IPD cohort was 5.0 years. This cohort study showed that the cumulative incidence of OAB was 0.65% at the fifth year and 1.54% at the tenth year after IPD diagnosis; this risk was highest in the age group 65–74 years. Conclusion: This study reveals that IPD is independently associated with an increased risk of OAB in patients with IPD. The probability of OAB was 1.54% over a 10-year period after IPD diagnosis; the risk of OAB is considered to be age-dependent and most substantial in patients aged 65–74 years. [ABSTRACT FROM AUTHOR]

Background/purpose: Vascular calcification can predict cardiovascular (CV) morbidity and mortality in patients with end-stage renal disease. We evaluated the prevalence, association factors, and outcomes of chest X-ray-detected aortic arch calcification (AoAC) in patients undergoing peritoneal dialysis (PD).Methods: We included 190 patients undergoing PD (mean age, 52.6 ± 14.3 years) for whom chest radiographs were available. AoAC revealed by chest X-ray was graded from 0 to 3 according to an AoAC score (AoACS). Multiple regression analyses were used to determine the factors associated with AoACS. After adjusting for age, sex, PD duration, diabetes mellitus, mean blood pressure, and history of CV disease, the association between AoAC grading and mortality were assessed using the Kaplan-Meier curve and Cox proportional hazard model.Results: Age (p < 0.001), PD duration (p = 0.004), history of CV disease (p < 0.001), and renal Kt/V (p = 0.031) were associated with AoACS. After a mean follow-up of 55.1 ± 32.1 months, patients with Grade 2 (p = 0.011) or Grade 3 (p < 0.001) AoAC had higher all-cause mortality than patients with Grade 0 AoAC. In addition, patients with Grades 2 and 3 AoAC had higher CV-related mortality than those with Grades 0 and 1 AoAC (p = 0.013). Grade 2 [hazard ratio (HR) = 2.736; 95% confidence interval (CI), 1.038-7.211; p = 0.042] and Grade 3 AoAC (HR = 3.289; 95% CI, 1.156-9.359; p = 0.026) remained associated with all-cause mortality after adjustment. Similarly, Grades 2 and 3 AoAC (HR = 36.05; 95% CI, 3.494-372; p = 0.026) significantly correlated with CV mortality after adjustment.Conclusion: In patients undergoing PD, CXR-detected severe AoAC was an independent risk factor for all-cause and CV mortalities. [ABSTRACT FROM AUTHOR]

Background: Gastroesophageal reflux disease (GERD) has become a major health problem globally, affecting patients' health-related quality of life (HRQOL). Barrett's esophagus (BE) is a precancerous lesion associated with GERD. BE patients might not only suffer from HRQOL losses by GERD but also face psychological distress due to the increased risk of developing cancer. However, the majority of patients in Asia have shorter BE segment which is different from the West. This study aimed to determine whether the HRQOL in BE patients were worse than in healthy referents in Taiwan. Methods: Patients who received referral esophagogastroduodenoscopy for various symptoms were evaluated for the existence of BE. Lesions were judged as endoscopically suspected esophageal metaplasia (ESEM) if they showed morphological resemblances to BE by endoscopy. The diagnosis of BE was confirmed by histology with intestinal metaplasia or gastric metaplasia based on the Montreal definition. The World Health Organization Quality of Life (WHOQOL-BREF) was administered to BE patients before treatment. For each BE patient, we selected 2 age-, sex-, educational background and municipality-matched healthy referents, sampled by simple randomization method from a national survey in Taiwan. Multiple linear regression models were constructed to control the potential confounders. Results: A total of 84 patients diagnosed with BE were enrolled as BE group and then compared with 168 healthy referents. The BE group had significantly lower WHOQOL-BREF scores than those of healthy referents in the physical domain (P < 0.05) but higher scores in the environment domain (P < 0.05). In the physical domain, the BE group had significantly lower scores in various facets, including pain, discomfort, sleep and rest and dependence on medications or treatments. There was no significant difference in social and psychological domains between the BE group and healthy referents. Conclusions: BE patients suffer from poor sleep and rest and high dependence on medications, which significantly reduce their quality of life. Individual facets of each domain warrants a better clinical healthcare to improve quality of life of BE patients. [ABSTRACT FROM AUTHOR]

Background/purpose: Quality of life (QoL) is found to be lower in heroin addicts; however, few studies examine detailed QoL performance and related factors in heroin patients attending a methadone maintenance treatment program (MMTP). The study thus aimed to explore QoL and its determinants for publicly-funded and self-paid patients attending an MMTP.Methods: Participants were recruited in Jianan Psychiatric Center, Tainan, Taiwan, during their first clinic visit for the MMTP. Age-, sex-, education-, and municipality-matched referents were collected from the 2001 Taiwan National Health Interview Survey database. The participants had a mean age of 38.29 years [standard deviation (SD) = 7.65 years] for publicly-funded (n = 129) and 37.97 years (SD = 7.16 years) for self-paid (n = 105) MMTP patients. Matched referents (n = 217) were 37.74 years (SD = 7.44 years). All participants were measured with the brief version of the World Health Organization's Quality of Life (WHOQOL-BREF) assessment. MMTP patients additionally went through tests for the hepatitis B virus, hepatitis C virus, and human immunodeficiency virus (HIV).Results: Both publicly-funded and self-paid MMTP patients had lower QoL scores than their matched counterparts in the physical and psychological domains (p < 0.05) after control for confounding by age, sex, education, and municipality. Detailed individual item analyses showed that publicly-funded MMTP patients had lower scores for almost all items related to the physical, psychological, and social domains as compared to the referents because of HIV infection (p < 0.05).Conclusion: To improve the QoL of heroin users coming for MMTP, we recommend that clinicians pay attention to the comorbidity of HIV infection and individual items/facets. [ABSTRACT FROM AUTHOR]

Background: Polyneuropathy presumably lowers quality of life (QoL). However, there is a lack of systematic studies that assess QoL changes and biomarkers of polyneuropathy as determinants of QoL. We aimed to investigate the relationship between every specific aspect of QoL and the clinical parameters used to assess the impairment of motor, sensory (large and small fibers), and autonomic nerves in polyneuropathy.Methods: Polyneuropathy patients were recruited from September 2013 to March 2014; QoL was assessed using (1) the WHO Quality of Life-BREF (WHOQoL), (2) the European Quality of Life-5 Dimensions, and (3) the Brief Pain Inventory Short Form. Neuropathy examinations included nerve conduction studies, autonomic function tests, quantitative sensory testing (QST), and intraepidermal nerve fiber (IENF) density assessment of skin biopsies.Results: There were 61 polyneuropathy patients (male/female = 38/23, mean age 58.14 ± 12.95 years). Patients had a lower QoL than age-and gender-matched controls in the physical and psychological domains of the WHOQoL. Among the biomarkers for different nerve fiber categories, only the small fiber neuropathy assessments were significantly related to all domains of the WHOQoL. In contrast, the parameters of the large fiber neuropathy were independent of QoL. Patients with abnormal temperature thresholds and a lower IENF density had lower WHOQoL scores compared to patients with normal thresholds and IENF densities. Warm threshold of the foot in QST was linearly correlated with all domains of the WHOQoL.Conclusions: QoL scores were reduced in polyneuropathy, and biomarkers of small fiber neuropathy, i.e., warm threshold and IENF density were discriminating predictors of QoL. [ABSTRACT FROM AUTHOR]

Background We applied the well-established, but rather under-utilized, indicator of Potential Years of Life Lost (PYLL) to estimate the global burden of mesothelioma and asbestosis. Methods We analyzed all deaths caused by mesothelioma and asbestosis that were reported by 82 and 55 countries, respectively, to the World Health Organization (WHO) from 1994 to 2010. Results The 128,015 and 13,885 persons who died of mesothelioma and asbestosis, potentially lost a total of 2.18 million and 180,000 years of life (PYLL), or, an annual average PYLL of 201,000 years and 17,000 years, respectively. The average PYLL per decedent were 17.0 and 13.0 years for mesothelioma and asbestosis, respectively. Conclusions The current burden of asbestos-related diseases (ARDs) in terms of PYLL is substantial. The future burden of ARDs can be eliminated by stopping the use of asbestos. Am. J. Ind. Med. 56:993-1000, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Background: Hazardous waste sites are major environmental concerns, but few studies have quantified their expected utility loss on health. Objectives: To evaluate the health impact of groundwater pollution by an electronics manufacturing factory, we conducted a health risk assessment based on expected utility loss from liver cancer. Methods: Based on measurements of major pollutants, we estimated the likelihood of developing liver cancer after exposure to groundwater contamination. All patients with liver cancer between 1990 and 2005 in the Taiwan Cancer Registry were followed through 2007 using the National Mortality Registry to obtain survival function. Quality of life was assessed with two cross-sectional surveys, one employing the standard gamble method, and the other using the EQ-5D instrument. Quality-adjusted life expectancy (QALE) was estimated by multiplying the utility values with survival function under the unit of quality-adjusted life year (QALY). The difference of QALE between the cancer cohort and the age- and gender-matched reference population was calculated to represent the utility loss due to liver cancer. Results: A total of 94,144 patients with liver cancer were identified. The average utility loss to development of liver cancer was 17.5 QALYs. Based on toxicological approach, we estimated that groundwater pollution caused 1.7 extra cases of liver cancer, with an overall loss of 29.8 QALYs. Based on epidemiological approach, the expected annual excess number of liver cancer would be 3.65, which would have been accumulated through the years, had the pollution not mitigated. Conclusions: We demonstrated a practical approach for comparative health risk assessment using QALY as the common unit. This approach can be used for policy decisions based on possible health risks. [Copyright &y& Elsevier]

ZnO/ZnS nanocomposite-based nanostructures exhibit dual light and gas sensing capabilities. To further boost the light/dual sensing properties, gold nanoparticles (Au NPs) were incorporated into the core-shell structures. Multiple material characterizations revealed that Au NPs were successfully well spread and decorated on ZnO/ZnS nanostructures. Furthermore, our findings show that the addition of Au NPs could enhance both 365 nm UV light sensing and hydrogen gas sensing in terms of light/gas sensitivity and light/gas response time. We postulate that the optimization of gas/light dual sensing capability may result from the induced electric field and inhabitation of electron-hole recombination. Owing to their compact size, simple fabrication, and stable response, ZnO/ZnS/Au NPs-based light/gas dual sensors are promising for future extreme environmental monitoring. [ABSTRACT FROM AUTHOR]

Background: In 1994, a hazardous waste site, polluted by the dumping of solvents from a former electronics factory, was discovered in Taoyuan, Taiwan. This subsequently emerged as a serious case of contamination through chlorinated hydrocarbons with suspected occupational cancer. The objective of this study was to determine if there was any increased risk of breast cancer among female workers in a 23-year follow-up period. Methods: A total of 63,982 female workers were retrospectively recruited from the database of the Bureau of Labor Insurance (BLI) covering the period 1973-1997; the data were then linked with data, up to 2001, from the National Cancer Registry at the Taiwanese Department of Health, from which standardized incidence ratios (SIRs) for different types of cancer were calculated as compared to the general population. Results: There were a total of 286 cases of breast cancer, and after adjustment for calendar year and age, the SIR was close to 1. When stratified by the year 1974 (the year in which the regulations on solvent use were promulgated), the SIR of the cohort of workers who were first employed prior to 1974 increased to 1.38 (95% confidence interval, 1.11-1.70). No such trend was discernible for workers employed after 1974. When 10 years of employment was considered, there was a further increase in the SIR for breast cancer, to 1.62. Those workers with breast cancer who were first employed prior to 1974 were employed at a younger age and for a longer period. Previous qualitative studies of interviews with the workers, corroborated by inspection records, showed a short-term high exposure to chlorinated alkanes and alkenes, particularly trichloroethylene before 1974. There were no similar findings on other types of cancer. Conclusion: Female workers with exposure to trichloroethylene and/or mixture of solvents, first employed prior to 1974, may have an excess risk of breast cancer. [ABSTRACT FROM AUTHOR]

We conducted this study to estimate residents' chronic hazard and carcinogenic risk in a groundwater-contaminated community after on-site remediation in Taiwan during 1999-2000. We followed guidelines for assessing hazardous waste sites of the U.S. Environmental Protection Agency (EPA) and used empirically measured contaminant levels and exposure parameters to perform health risk assessment on seven chlorinated hydrocarbons. We measured groundwater concentrations of vinyl chloride, tetrachloroethylene, trichloroethylene, 1,1-dichloroethylene, 1,1,1-trichloroethane, cis-1,2-dichloroethylene, and 1,1-dichloroethane in 49 off-site residential wells by gas chromatography/mass spectrometry. Exposure parameters were mainly derived from our field survey of 382 residents, and partially from U.S. EPA default values. Total exposure dose estimation included routes of inhalation during showering and dermal absorption of showers and other activities involved with hand-water contacts. The ingestion route of water was not included because most residents drank boiled water with negligible contaminants. We calculated a hazard index (HI) for all seven chlorinated hydrocarbons and carcinogenic risks for known human carcinogen of vinyl chloride and probable human carcinogens of tetrachloroethylene and trichloroethylene, which had the same target organ, the liver. The HI values for reasonable maximal exposure (RME) and average exposure were 14.3 and 0.2, respectively. The cancer risks based on RME and average exposure (in parentheses) for vinyl chloride, tetrachloroethylene, and trichloroethylene were 8.4 × 10[sup -6] (7.3 × 10[sup -9]), 1.9 × 10[sup -4] (1.3 × 10[sup -7]), and 1.4 × 10[sup -4] (1.2 × 10[sup -6]), respectively. We applied Monte Carlo simulations to the sensitivity analysis, which showed that the contaminant levels, exposure duration, and time for showers were major determinants of health risks. We concluded that the contaminated groundwater was still unsafe for use even after the contaminated site underwent remediation by extraction and treatment in 1997. [ABSTRACT FROM AUTHOR]

Schizophrenia is a multifactorial developmental neuropsychiatric disorder. This study examined the interplay of maternal infection and postweaning social isolation, which are prenatal and postnatal risk factors, respectively. Pregnant mice received poly I:C or saline injection on gestation day 9 and the pups were weaned at postnatal day 28. After weaning, male offspring were randomly assigned into group-rearing and isolation-rearing groups. In their adulthood, we performed behavioral tests and characterized the histochemical features of their mesocorticolimbic structures. The sociability and anxiety levels were not affected by either manipulation, but synergistic effects of the two hits on stress-coping behavior was observed. Either of the single manipulations caused defects in sensorimotor gating, novel object recognition and spatial memory tests, but the combination of the two hits did not further exacerbate the disabilities. Prenatal infection increased the number of dopaminergic neurons in midbrain, whereas postweaning isolation decreased the GABAergic neurons in cortex. Single manipulation reduced the dendritic complexity and spine densities of neurons in the medial prefrontal cortex (mPFC) and dentate gyrus. Our results support the current perspective that disturbances in brain development during the prenatal or postnatal period influence the structure and function of the brain and together augment the susceptibility to mental disorders, such as schizophrenia. [ABSTRACT FROM AUTHOR]

Objective: This paper aimed to determine the standardised incidence ratio (SIR) of malignant pleural mesothelioma (MPM) in workers exposed to asbestos in Taiwan.Methods: All workers employed in asbestos-related factories and registered by the Bureau of Labour Insurance between 1 March, 1950, and 31 December, 1989, were included in the study and were followed from 1 January, 1980, through 31 December, 2009. Incident cases of all cancers, including MPM (ICD-9 code: 163), were obtained from the Taiwan Cancer Registry. SIRs were calculated based on comparison with the incidence rate of the general population of Taiwan and adjusted for age, calendar period, sex, and duration of employment.Results: The highest SIR of MPM was found for male workers first employed before 1979, with a time since first employment more than 30 years (SIR 4.52, 95% CI: 2.25-8.09). After consideration of duration of employment, the SIR for male MPM was 5.78 (95% CI: 1.19-16.89) for the workers employed for more than 20 years in asbestos-related factories.Conclusions: This study corroborates the association between occupational asbestos exposure and MPM. The highest risk of MPM was found among male asbestos workers employed before 1979 and working for more than 20 years in asbestos-related factories. [ABSTRACT FROM AUTHOR]