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Biomedical subjects

J D Wang

Publications and source records attributed to J D Wang.

At least 73 records · Page 4Linked to original sources
PubMed1998

Radiation exposure modeling for apartment living spaces with multiple radioactive sources.

Since late 1992, over 100 building complexes in Taiwan, including both public and private schools, and 1,000 apartments have been identified as emitting elevated levels of gamma-radiation. These high levels of gamma-radiation have been traced to construction steel contaminated with 60Co. Accurate reconstruction of the radiation exposure dosage among residents is complicated by the discovery of multiple radioactive sources within the living spaces and by the lack of comprehensive information about resident life-style and occupancy patterns within these contaminated spaces. The objective of this study was to evaluate the sensitivity of current dose reconstruction approach employed in an epidemiological study for the health effects of these occupants. We apply a statistical method of local smoothing in dose rate estimation and examine factors that are closely associated with radiation exposure from multiple radioactive sources in the apartment. Two examples are used, a simulated measurement in a hypothetical room with three radioactive sources and a real apartment in Ming-Shan Villa, one of the contaminated buildings. The simulated and estimated means are compared along 5-10 selected points of measurement: by local smoothing approach, with the furniture-adjusted space, and with the occupancy time-weighted mean. We found that the local smoothing approach came much closer to theoretical values. The local smoothing approach may serve as a refined method of radiation dose distribution modeling in exposure estimation. Before environmental exposure assessment, "highly occupied zones" (HOZs) in the contaminated spaces must be identified. Estimates of the time spent in these HOZs are essential to obtain accurate dosage values. These results will facilitate a more accurate dose reconstruction in the assessment of residential exposure in apartments with elevated levels of radioactivity.

Air Pollution, Radioactive↗
PubMed1998

Plasma Asp13-Ki-ras oncoprotein expression in vinyl chloride monomer workers in Taiwan.

Vinyl chloride (VC) workers are known to be at risk for development of liver angiosarcoma, a rare tumor. Previously, more than 80% of VC workers with liver angiosarcoma have been found to have an Asp-13 c-Ki-ras oncogene mutation, and more than 50% of VC-exposed workers without liver tumors were found to have Asp13-Ki-ras oncoprotein in their plasma. Some workers in Taiwan had also been exposed to VC, and some have contracted liver tumors. In this study, we used enhanced chemiluminescence Western blotting to detect Asp13-p21-Ki-ras in the sera of VC-exposed workers in Taiwan. There were 14 of 113 (12.4%) VC workers positive for the Asp13-Ki-ras oncoprotein in plasma, but 0 of 18 controls were positive. There were 10 of 69 (14.5%) plasma-positives among the more highly exposed (> 1000 ppm-months) workers and 4 of 48 (9.1%) plasma-positives among the lesser exposed (< or = 1000 ppm-months). Compared with the unexposed controls, the odds ratios (and 95% confidence intervals [CI]) for plasma-positivity were 4.11 (95% CI = 0.21, 80.4) in the lower-exposed workers and 6.53 (95% CI = 0.37, 116.9) in the higher-exposed workers, and there was a linear trend between exposure and plasma-positivity (P = 0.073). After adjusting for age and drinking status, the odds ratios (and 95% CIs) were 1.64 (95% CI = 0.17, 15.8), and 2.65 (95% CI = 0.42, 16.8), respectively, and there was a significant linear trend between exposure and plasma-positivity (P = 0.048). In summary, Asp13-Ki-ras oncoprotein can be found in the plasma of VC workers in Taiwan, and a significant dose-response relationship exists between plasma oncoprotein expression and VC exposure.

Adult↗
PubMed1998

Increased morbidity odds ratio of primary liver cancer and cirrhosis of the liver among vinyl chloride monomer workers.

OBJECTIVES: To determine if there is an increased risk of admission to hospital for various diseases among vinyl chloride monomer (VCM) workers. METHODS: 2224 workers with occupational exposure to VCM were identified for occurrence of disease based on a search of hospital computer files on labour insurance. These data were compared with those of workers manufacturing optical equipment and motorcycles from 1 January 1985 to 31 March 1994. Cardiovascular and cerebrovascular diseases were used as reference diseases, and the age adjusted morbidity odds ratio (MOR) was calculated. RESULTS: A significantly increased risk of admission to hospital among VCM workers due to primary liver cancer (MOR 4.5-6.5), cirrhosis of the liver (MOR 1.7-2.1), and other chronic diseases (MOR 1.5-2.0) was found. There were eight cases of primary liver cancer, all with heavy previous exposure to VCM. Another four cases of hepatoma in polyvinyl chloride (PVC) workers were found in the death registry. Ten out of 11 cases of hepatoma, with detailed medical information, were carriers of hepatitis B virus. The average latent period (20 years) was not different from other studies. Alternative agents of primary liver cancer were largely ruled out, suggesting that the combination of hepatitis B and VCM may lead to primary liver cancer. CONCLUSION: There is an increased risk of primary liver cancer in workers exposed to VCM, although the incomplete coverage of the Labor Insurance Bureau data warrants cautious interpretation of the results. Further study exploring the synergistic effects of VCM and hepatitis B is also indicated.

Adult↗
PubMed1998

Chinese herbal medicine, sibship, and blood lead in children.

OBJECTIVES: Risk factors for increased blood lead concentration (BPb) has been investigated. However, the effect of sibship and Chinese herbal medicine on BPb has not been systematically studied. In this study BPb data from voluntary testing was used to determine if Chinese herbal medicine and sibship were associated with BPb. METHODS: 319 children aged 1-7 were tested for BPb. Meanwhile, parents were interviewed to obtain information including consumption of Chinese herbal medicine, living environment, lifestyle, and sibship of the children tested. RESULTS: The mean (SD) BPb of 319 preschool children was 4.4 (2.4) micrograms/dl. The consumption of Ba-baw-san (a Chinese herbal medicine) was significantly associated with increased BPb in children (p = 0.038). Further multivariate regression analysis of BPb in 50 pairs of siblings showed the factors of being brothers explained 75% of variation for BPb, and being sisters and brother-sister explained 51% and 41% of variation respectively. CONCLUSION: Chinese herbal medicine and children's play patterns within the family expressed in different types of sibship are the main determinants of low concentrations of BPb in preschool children of Taiwan.

Age Factors↗
PubMed1998

Pregnane glycosides, gymnepregosides A-F from the roots of Gymnema alternifolium.

The structural elucidation of six new related polyoxypregnane glycosides, gymnepregosides A (1), B (2), C (3), D (4), E (5) and F (6), together with two known compounds, from the roots of Gymnema alternifolium (Asclepiadaceae) was achieved through on a detailed study of 1H- and 13C-NMR spectral data and chemical means. The results obtained for new compounds, 1-6, show that they are (20S)-pregn-6-ene-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta,20-heptaol or sarcostin 3-O-glycosides, and all the sugars at C-3 are beta(1-->4)-linked. Some of them possessed benzoyl, cinnamoyl and tigloyl residues as the ester linkages located at C-12 and/or C-20 of the aglycon.

Carbohydrate Sequence↗
PubMed1998

Adverse effect of air pollution on respiratory health of primary school children in Taiwan.

This study is a part of the Study On Air Pollution and Health In Taiwan (SOAP&HIT), an ongoing research project involving cooperation of several universities in Taiwan. In this study, the objective was to evaluate the effects of ambient air pollution on respiratory symptoms and diseases of school children, in addition to considering indoor air pollution. Six communities were selected: one community located in a rural area (Taihsi), two in urban areas (Keelung and Sanchung), and the other three in petrochemical industrial areas (Toufen, Jenwu, and Linyuan). We sampled 5,072 primary school students in six communities from the main study population of SOAP&HIT. Respiratory health was assessed by evaluation of the children's respiratory symptoms and diseases using a parent-completed questionnaire. Data were analyzed using logistic regression analysis to compute odds ratios of adverse effect. The school children in the urban communities had significantly more respiratory symptoms (day or night cough, chronic cough, shortness of breath, and nasal symptoms) and diseases (sinusitis, wheezing or asthma, allergic rhinitis, and bronchitis) when compared with those living in the rural community. However, only nasal symptoms of children living in the petrochemical communities were more prevalent than in those living in the rural community. Although the association with ambient air pollution is suggestive, the cross-sectional study cannot confirm a causal relationship; thus further studies are needed.

Air Pollution↗
PubMed1998

Occupational and environmental lead poisoning: case study of a battery recycling smelter in Taiwan.

The rapid industrialization in Taiwan has caused both prosperity and environmental pollution. The purpose of this study is to demonstrate a case of both occupational and environmental lead poisoning. A patient of lead poisoning initiated a survey of the battery recycling factory, which revealed that 31 of 64 workers suffered from lead poisoning. Children who attended a nearby kindergarten showed a significant increase of blood lead up to 15-25 micrograms/dl and a mild but significant decrease of IQ (intelligent quotient, by Binet-Simon scale) if compared with children of a nonexposed but socioeconomically comparable kindergarten. Outdoor workers of the nearby forging factory also showed a significant increase of blood lead if compared with indoor workers or workers of another nonexposed forging factory 20 Km away. Air sampling showed an average of more than 10 micrograms/m3 in the kindergarten. Soil sampling and analysis also revealed 400 folds increase of lead content, which decreased if the sample was taken deep down to 15-30 cm or 350 meters away from the battery recycling smelter. Moreover, after children were moved away from the pollution source, follow-up examination performed 2.5 years later showed a significant decrease of blood lead and partial recovery of IQ among them.

Adolescent↗
PubMed1998

Seasonal variation of chickenpox, mumps and rubella in Taiwanese children estimated by pediatric clinics.

To determine the seasonal variation of childhood infectious diseases in Taiwan, the incidence rates of chickenpox, mumps and rubella were studied by analyzing patient's records collected from pediatric clinics in northern, central, southern and eastern Taiwan from January 1, 1993 to December 31, 1993. The study revealed that a chickenpox outbreak was most likely to occur in autumn, followed by a second peak in spring, and the lowest rate in summer. In this study, the highest monthly incidence of chickenpox was 540 cases per 100,000 population. The highest incidence of mumps occurred in the spring, the second highest in autumn, and the lowest during summer. Cases of rubella occurred in the spring, summer and autumn, but not in the winter. The data on chickenpox from this study revealed a similar seasonal pattern every year to that of the Department of Health of the National Quarantine Service on Taiwan. The chickenpox virus is known to be relatively sensitive to elevations in ambient temperature and is characterized by its occurrence mainly in slightly humid seasons.

Chickenpox↗
PubMed1998

Determinants of lethality from suicidal pesticide poisoning in metropolitan HsinChu.

Acute pesticide poisoning is a global health problem, especially in developing countries. Although Taiwan has quickly industrialized during the last several decades, pesticide use is still prevalent in the agricultural sector. We reviewed 187 consecutive hospitalized cases of the Provincial HsinChu Hospital from January 1989 through December 1995 to explore the determinants of acute pesticide poisoning in Metropolitan HsinChu. The annual incidence rate of acute pesticide poisoning was 3.2/100,000 with an overall fatality rate of 23% which was more severe than the rates found in developed countries. The major agents involved were organophosphates, and the major cause of poisoning was suicide. Alcohol abuse, history of major medical illnesses, and history of suicide were significantly associated with suicidal poisoning; quarrel was the immediate risk factor. Causes of poisoning (suicide vs non-suicide) and selection of the pesticides were major determinants of lethality. More stringent legislation and enforcement regarding the sale and distribution of extremely toxic pesticides are needed to reduce fatalities due to acute pesticide poisoning.

Adolescent↗
PubMed1997

VOC concentration in Taiwan's household drinking water.

The objective of this study is to analyze volatile organic compound (VOC) concentrations in Taiwan's drinking water supply. Focusing on Taiwan's three major metropolitan areas--Taipei, Taichung and Kaohsiung (in the north, middle and south, respectively)--171 samples were taken from tap water and 68 from boiled water. Tests showed VOC concentrations were highest in Kaohsiung. This is due to different water sources and methods of treatment. Except for bromoform, trihalomethane (THM) concentrations were highest. Detection rates of toluene and 1,2-dichloroethane were slightly higher than other VOC compounds. VOC concentrations decreased significantly after water was boiled. THMs had a removal rate from 61% to 82%. The authors conclude that the three metropolitan areas contain significantly different levels of VOCs and that boiling can significantly reduce the presence of VOCs. Other sources of pollution that contaminate drinking water such as industrial plants and gas stations must be further investigated.

Environmental Exposure↗
PubMed1997

Cytogenetic effect of chronic low-dose, low-dose-rate gamma-radiation in residents of irradiated buildings.

BACKGROUND: Many people in Taiwan have been living in buildings constructed with cobalt-60-contaminated steel rods. To study the biological effects of chronic low-dose ionising radiation on the residents of one such building, micronucleus formation in these individuals was compared with that in controls. METHODS: The 73 residents had 77 age-and-sex-matched controls: 31 had 31 close relatives as controls (group A controls); eight of the 31 had a second set of close relatives; and the other controls were 38 residents in neighbouring buildings. Two micronucleus assays were used-a cytochalasin B (CBMN) assay and another involving incubation with cytarabine (CBMNA). Assay results are given as "frequency", or the number of binucleate cells containing one micronucleus per 1000 randomly examined binucleate cells. FINDINGS: The CBMN and CBMNA mean (SD) frequencies for 31 exposed individuals (0.016 [0.009] and 0.025 [0.013] respectively) were greater than those for their group A controls (0.009 [0.004] and 0.016 [0.009], respectively) (p = 0.0006 and 0.0002, respectively). The mean CBMN and CBMNA frequencies for all the exposed individuals (0.017 [0.011] and 0.030 [0.014], respectively) were significantly greater than those for all controls (0.011 [0.008] and 0.019 [0.01]; p = 0.0001 for both comparisons). The ranges of the differences in CBMN or CBMNA frequencies between 31 exposed individuals and their group A controls were 0.003 to 0.020 and 0.001 to 0.032, respectively. After adjustment for age, sex, and cigarette smoking, the adjusted relative risks of micronucleus formation from radiation exposure in all 73 residents was 1.58 (95% CI 1.42-1.71; p = 0.0001) by the CBMN assay and 1.64 (1.53-1.77; p = 0.0001) by the CBMNA assay. INTERPRETATION: These findings suggest that chronic low-dose and low-dose-rate gamma-ray environmental exposure may induce cytogenetic damage in human beings.

Adolescent↗
PubMed1997

Neurobehavioral effects of occupational exposure to low-level organic solvents among Taiwanese workers in paint factories.

At six paint factories in northern Taiwan, 325 workers participated in a detailed evaluation that included medical and occupational questionnaires, blood sampling, neurobehavioral tests, vibratory perception threshold tests, and thermal perception threshold tests. Because of cultural differences, a Chinese test battery was modified from the Neurobehavioral Evaluation System 2. Eleven tests were performed: finger tapping, continuous performance, associated learning, symbol-digit, pattern comparison, pattern memory, visual digit span, switch attention, associated delayed recognition, mood scales, and vocabulary. Air concentrations of organic solvents were measured by passive personal samplers and analyzed by gas chromatography. Results showed that major solvents to which the workers were exposed were toluene, xylene, n-hexane, methyl iso-butyl ketone, and n-butyl acetate. The exposure index (EI) was classified by different exposure patterns and different air concentrations in the breathing zone as follows: EI 0, nonexposure; EI 1, low exposure; and EI 2, high exposure (the medians of 8-hr hygienic effects were 0, 0.03, and 0.25, respectively). Because of their diverse socioeconomic status and demographic characteristics, the workers were divided into two groups for additional analysis: one group comprised white-collar workers, including technicians and administrative staff, and the other comprised blue-collar workers. By using multiple linear regression analysis controls for age, sex, education, and alcohol intake, significant associations were found between increased exposure to solvent mixtures and performance on some neuropsychologic tests. In the blue-collar group, significantly prolonged response latencies were observed in the tests of continuous performance, pattern comparison, and pattern memory. Among white-collar workers, significant impairment was observed in the continuous performance test. All three tests involved visual attention and perceptual (speed and memory) functions. It was concluded that these may be the earliest neurotoxic signs of occupational exposure to low-level organic solvents in paint manufacturing workers.

Adolescent↗
PubMed1997

Respiratory and irritant health effects of a population living in a petrochemical-polluted area in Taiwan.

Reported herewith are the results from an ongoing study of outdoor air pollution and the health of persons living in the communities in close proximity to petrochemical industrial complexes. To determine if there is an excess of adverse health outcomes in the population exposed to petrochemical industrial emissions, a health survey was undertaken in 1996 in this area and in one reference area which has no local industrial emissions. The subjects were 436 adults (30-64 years of age) living in the Sanwei area (exposed area) and 488 in Taicei (reference area). For several indicators of respiratory health, including cough, wheezing, and chronic bronchitis, the prevalence rates were not significantly different between the study and the control populations. Acute irritative symptoms (eye irritation, nausea, throat irritation, and chemical odor perception) were significantly more common in the exposed area, particularly perception of chemical odors (84.6% vs 2.1%). It is concluded that exposure to petrochemical air emissions may be associated with increased rates of acute irritative symptoms. Future studies are needed to identify the potential role of petrochemical industrial emissions (particularly volatile organic compounds) in the genesis of acute irritative symptoms in a nearby petrochemical industrial area.

Adult↗
PubMed1997

The GST T1 and CYP2E1 genotypes are possible factors causing vinyl chloride induced abnormal liver function.

Vinyl chloride monomer (VCM) is hepatotoxic as well as carcinogenic in humans. There are reports that exposure to VCM seems to induce abnormal liver function, liver fibrosis, cirrhosis, portal hypertension, and angiosarcoma of the liver. In vivo, VCM is metabolized by cytochrome P450 2E1 (CYP2E1) to form the electrophilic metabolites, chloroethylene oxide (CEO) and chloroacetaldehyde (CAA), which may either cause cell damage or be further metabolized and detoxified by glutathione S-transferases (GSTs). This study investigated whether or not the genotypes CYP2E1, glutathione S-transferase theta (GST T1) and mu (GST M1) correlated with abnormal liver function found in vinyl chloride exposed workers. For this study, 251 workers from five polyvinyl chloride plants were enrolled. The workers were classified into two exposure groups (high and low) and the degree of exposure was determined based on their job titles and airborne VCM concentration. The activity of serum alanine aminotransferase (ALT) was used as the parameter of liver function. The genotypes CYP2E1, GST T1 and GST M1 were determined by polymerase chain reaction and restriction fragment length polymorphism on peripheral white blood cell DNA. Other potential risk factors were also ascertained and the confounding effect was adjusted accordingly. Stratified analyses were used to explore the correlation between the alteration of liver function and the genotypes CYP2E1, GST T1 and GST M1 among the workers exposed to different levels of VCM. The following results were obtained (1) at low VCM exposure, the odds ratio (OR) of positive GST T1 on abnormal ALT was 3.8 (95% CI 1.2-14.5) but the CYP2E1 genotype was not associated with abnormal ALT. (2) At high VCM exposure, a c2c2 CYP2E1 genotype was associated with increased OR on abnormal ALT (OR 5.4, 95% CI 0.7-35.1) and positive GST T1 was significantly associated with decreased OR on abnormal ALT (OR 0.3, 95% CI 0.1-0.9). (3) Multiple linear and logistic regression also showed strong interactions of the VCM exposure to CYP2E1 as well as to the GST T1 genotype. These observations suggest that the two genotypes, CYP2E1 and GST T1, may play important roles in the biotransformation of VCM, the effect of which leads to liver damage.

Adult↗
PubMed1997

60Co contamination in recycled steel resulting in elevated civilian radiation doses: causes and challenges.

Since late 1992, more than 100 building complexes containing public and private schools and nearly 1,000 apartments have been identified in Taiwan with elevated levels of gamma-radiation from construction steel contaminated with 60Co. Due to improper handling of 60Co contaminated scrap steel in late 1982 and 1983, contaminated construction materials have been widely distributed throughout the country. These contaminated construction materials have generated elevated radiation exposures to members of the public in Taiwan. As of early 1996, more than 4,000 people, including young students, have been identified as receiving more than 1 mSv y(-1) above the local background for up to 12 y. This report provides a detailed discussion of the sources of the 60Co contamination in construction steel, its discovery in the building complexes, and preliminary evaluation and remediation activities.

California↗
PubMed1997

Predictive pulmonary function of school children in an area of low air pollution in Taiwan.

The objective of this study was to determine the effect of different parameters on a predictive model of pulmonary function for elementary school children in an area of low air pollution in Taiwan. Healthy children aged 7 to 12 years from three elementary schools in low-air-pollution areas (Da-Chen, Mai-Liau and Tai-Si) participated in the study. A total of 836 children (423 boys and 413 girls) were included in the study. During summer vacation, each child underwent a physical examination including a screening spirometry. A questionnaire regarding respiratory symptoms and indoor air pollutants was also completed by the children's parents. Air monitoring showed that the levels of outdoor pollutants were relatively low. Multiple linear regression analysis was performed with FVC (forced vital capacity) and FEV1 (forced expiratory volume in 1 sec) as dependent variables. Gender, age, height, weight, technician and indoor air pollution parameters were the independent variables. The results showed that gender,height, weight and technician were the most significant variables for predicting FVC and FEV1. The various indoor air pollution parameters seemed to have no influence on the pulmonary function of children, except that mildew in bedrooms mildly decreased FEV1. Regression analysis showed that all the pulmonary function parameters measured had a positive correlation with height, whereas weight correlated only with certain parameters. Because both indoor and outdoor air pollution was relatively low, we suggest that this model could be used as a basic predictive model of pulmonary function for elementary school children in Taiwan.

Air Pollution↗
PubMed1997

[Using polymerase chain reaction to detect Helicobacter heilmannii in gastric biopsy materials].

Helicobacter heilmannii is one of the species of Helicobacter other than Helicobacter pylori noticed in human gastric mucosa. In our study, a polymerase chain reaction (PCR) was designed for the detection of Helicobacter heilmannii in gastric biopsy specimens. Two broad-range bacterial 16S rDNA primers and one Helicobacter genus-specific 16S rDNA primer were matched for detecting Helicobacter genus bacteria. A Hp-specific primer pair was used simultaneously to exclude the presence of Hp. The PCR assay detected 11 out of 12 Hh strains which were confirmed by smears, but did not amplify DNA extracts from some other enteric bacteria such as E. coli, C. jejuni, bifidobacteria. Serial dilution experiments revealed the detection of as little as 0.1 pg DNA by PCR and 0.01 pg by nested PCR. Our data showed that PCR is a rapid, accurate and sensitive method for the detection of Hh and is thought valuable in the epidemiological investigation of Helicobacter and follow-up studies after treatment.

Biopsy↗