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Biomedical subjects

J D Wang

Publications and source records attributed to J D Wang.

At least 19 recordsLinked to original sources
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↗
PubMed1996

Estimation of expected quality adjusted survival by cross-sectional survey.

To compare both mortality and quality of life (QOL) across different illnesses, we propose an estimator to calculate the expected quality adjusted survival (QAS) by multiplying the QOL into the survival function. While the survival function can be determined by the usual life table method, the QOL data can be collected by a cross-sectional survey among patients who are currently surviving. The area under the QAS curve is thus the expected utility of health of the specific illness, which may take a common unit of quality adjusted life year ready for outcome evaluation and policy decision. A simulation is performed to demonstrate that the proposed estimator and its standard error are relatively accurate. The limitations and guidelines for using this estimator are also discussed.

Bias↗
PubMed1996

Age-period-cohort analysis of motor vehicle mortality in Taiwan, 1974-1992.

The aim of this study was to examine the effects of age, calendar period of death and birth cohort in motor vehicle mortality in Taiwan over the period 1974-1992. A log-linear model modified from the method of Osmond and Gardner (Stat. Med. 1: 245-259; 1982) was used. Age turned out to be a significant predictor of motor vehicle mortality. The most risky group (over 70 years) had 27.1 and 16.3 times the mortality of the least risky group (5-9 years, 10-14 years) for males and females respectively. The period effect showed a continuously increasing mortality trend since 1974 in females. The pattern in males is similar except that it has slightly leveled off in recent years. The birth cohorts at the highest risk of motor vehicle death were those born between 1979 and 1983 for both sexes. However, males born between 1929 and 1933 also had a high mortality. This analysis provided a better understanding of the trend of mortality from motor vehicle crashes.

Accidents, Traffic↗
PubMed1996

Progesterone receptor immunoreactivity at the maternofetal interface of first trimester pregnancy: a study of the trophoblast population.

The aim of our study was to localize oestrogen receptor (ER) and progesterone receptor (PR) in the trophoblast population at the maternofetal interface in early pregnancy. Rat monoclonal antibodies to human ER and PR were used to study 44 cases of chorionic villi and 82 cases of decidua using an immunocytochemical method. The PR-immunoreactive products were localized in the nuclei of syncytiotrophoblast and cytotrophoblast cells of the villi. Specific staining was also present in the cytoplasm. Villous stroma and vessels were stained occasionally. Using cytokeratin staining in an adjacent section or double staining with PR and cytokeratin, the distribution of invading trophoblast cells and their PR expression were examined. In decidual stroma, a type of interstitial cell was identified which simultaneously expressed cytokeratin and PR in the cytoplasm, indicating that the invading trophoblast cells may express PR. All extravillous populations at the interface were positive for PR, including the syncytial lining of the decidual surface, the cytotrophoblast column, the cytotrophoblast shell and the interstitial trophoblast. The immunoreactivity of PR was also localized in the nuclei of vascular endothelial cells, whereas Factor VIII was localized in the cytoplasm of the same cells, thus confirming their endothelial nature. In contrast to PR, little ER could be detected in the trophoblast cell population using anti-ER antibody D75 in our study.

Adult↗
PubMed1996

Prevalence of dermatoses and skin sensitisation associated with use of pesticides in fruit farmers of southern Taiwan.

OBJECTIVES: Agricultural workers are known to have occupational skin diseases. The prevalence and pattern of skin diseases are unknown in Taiwanese fruit farmers. The objective of this study is to determine the work exposure, prevalence of skin diseases, and sensitivity to common skin allergens and agricultural chemicals in fruit farmers of southern Taiwan. METHODS: 122 fruit farmers who regularly prepared and sprayed pesticides and a group of 63 printing press workers with no known exposure to pesticides were examined and patch tested with common skin allergens and agricultural chemicals. The farmers were also interviewed for their work habits, use of protective clothing, and exposure to pesticides. RESULTS: Most farmers reported regular use of hat, boots, and mask, but not gloves, raincoat, and goggles. This resulted in frequent skin contact with pesticides especially on the hands and face. About 30% of farmers had hand dermatitis, and more than two thirds had pigmentation and thickening on the hands. Fungal infection of the skin was noted in a quarter of subjects. By patch test, farmers and the printing press workers had a similar rate of sensitivity to common skin allergens. 40% of farmers were sensitive to agricultural chemical allergens, which was about twofold higher than that of the comparison group. Farmers were most frequently sensitive to Captofol, Folpet, and Captan which were associated with dermatitis on the volar aspects of the hands. CONCLUSIONS: Fruit farmers in southern Taiwan had a high prevalence of skin diseases related to use of pesticides, and appropriate protective measures and work practices should be taken to prevent such problems.

Adolescent↗
PubMed1996

Outbreak of contact dermatitis related to Acticide EP paste in a paint manufacturing factory.

An outbreak of severe itching, erythematous and edematous dermatitis over the extremities and upper back developed in 8 of 17 workers in the raw-materials department of a paint manufacturing factory. The outbreak occurred during a 2-month period when Acticide EP paste (Thor Chemical, Cheshire, UK) was used in place of Metatin as a microbiocide (Acima Chemical, Buchs, Switzerland). To evaluate the frequency and the etiologic agent of this outbreak, a plant walk-through, examination and review of photographs of skin lesions followed by statistical analysis for association between the development of dermatitis and exposure to Acticide paste were performed. Three guinea pigs were subjected to patch tests comparing the dermatotoxicity of Acticide EP and Metatin. The results showed that 8 out of 17 workers (47%) suffered from contact dermatitis during the 2-month period. Stratification by occupational exposure further confirmed the association between the development of dermatitis and exposure to the Acticide paste. The dermatotoxicity test on guinea pigs revealed the marked corrosive effect of the paste and the absence of dermatotoxicity of Metatin. After the removal of the paste from the raw material, there were no new cases of contact dermatitis at the 6 month follow-up. We conclude that Acticide EP paste was the responsible offending agent. Because isothiazolinone derivatives are well-known antigens and 2-n-octyl-4-isothiazolin-3-one is the active ingredient in Acticide EP paste, 2-n-octyl-4-isothiazolin-3-one is the likely cause of the dermatitis.

Animals↗
PubMed1995

Case-control study of the effectiveness of different types of helmets for the prevention of head injuries among motorcycle riders in Taipei, Taiwan.

A total of 1,351 victims of motorcycle accidents, brought to one of 15 hospitals responsible for emergency care in Taipei, Taiwan, between August 1 and October 15, 1990, were enrolled in a case-control study to investigate the effectiveness of different types of helmets for the prevention of head injuries. A total of 562 of those with head injuries were assigned to the case group, while the remaining 789 victims without head injuries were considered as emergency room controls. The case group was subdivided into daytime and evening cases, according to the time of accident. For each daytime case, we took four pictures of passing motorcycles at the same time and place during the week after each accident. Of the 254 daytime cases, we successfully took pictures for 224 (88%) and identified 1,094 motorcycle riders in the pictures as street controls. Logistic regression analyses were used to determine the roles of the following variables in predicting risk of head injury: age, sex, riding position, weather, place of accident, helmet type, and motorcycle type, and status of helmet wearing. The relative risk of head injury among motorcycle riders was significantly reduced by wearing a full-face helmet, but not by wearing a full- or a partial-coverage helmet.

Accidents, Traffic↗
PubMed1995

Subclinical neurotoxicity of mercury vapor revealed by a multimodality evoked potential study of chloralkali workers.

Pattern visual, brainstem auditory, and somatosensory evoked potential (EP) studies were performed on 26 chloralkali workers. The intensity of mercury vapor exposure in these workers was estimated from the individual working history. Mercury levels in blood, urine, and hair were determined with atomic absorption spectrometry. The EP findings were compared with those from individually matched normal subjects. In brainstem auditory and somatosensory EP studies, prolonged neural conduction times in the central nervous system (CNS) were found in workers exposed to mercury vapor. In the pattern visual EP study, mercury workers had higher interpeak amplitudes. Findings of this study suggested that chronic exposure to mercury vapor would affect the CNS functions. A multimodality EP study is a useful adjunct in evaluation of chronic mercury neurotoxicity, especially in an epidemiological study.

Adult↗
PubMed1995

Changes in lymphocyte single strand breakage and liver function of workers exposed to vinyl chloride monomer.

Vinyl chloride monomer (VCM) is a suspected human carcinogen. Its metabolite, chloroethylene epoxide, is able to alkylate the DNA molecule and to produce single strand breakage (SSB). A total of 244 workers from 4 polyvinyl chloride (PVC) manufacturing factories were recruited to assess the SSB of their peripheral lymphocyte DNA. The method of alkaline unwinding and hydroxyapatite chromatography was used to detect and calculate frequencies of SSB. In addition, hepatitis B and C markers and the liver function of the workers were also examined. The worker's cumulative exposures to VCM were retrospectively constructed from the current monitoring data and each worker's job history. Multiple linear regression models were constructed to predict the worker's level of SSB and liver functions based on various exposure indices and variables, such as age, sex, smoking, drinking, and hepatitis markers. The results showed that current smoking and drinking status, and the presence of VCM exposures on the previous day were 3 major determinants of the level of SSB. Among the liver function tests, only gamma-glutamyl transpeptidase (GGT) was associated with current VCM exposures. In contrast, aspartate aminotransferase (AST), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were mainly affected by the presence of hepatitis B surface antigen (HBsAg) or anti-hepatitis C virus (anti-HCV). We conclude that GGT should be considered to be included in the regular health screening of VCM workers, and that the SSB method may not be suitable for long-term monitoring of cumulative exposure because of the quick DNA repair mechanism in humans.

Adult↗
PubMed1995

Photodamage and skin cancer among paraquat workers.

BACKGROUND: Some workers in paraquat manufacturing, exposed to bipyridines, have developed pigmentation and keratosis on sun-exposed skin. This condition has been described as skin-malignancy or premalignancy. This study was designed to clarify the pathologic features of these lesions and to explore the etiologic role played by bipyridine. METHODS: Twenty-three biopsy specimens, obtained from the affected skin of 10 workers, were scrutinized by a dermatopathologist. A total of 242 exposed workers from 28 paraquat factories were examined and interviewed during the period from 1983 to 1991. The severity of the characteristic skin lesions was graded from the lowest to the highest response to analyze the data by Mantel extension for a trend that focused on the heavy exposure to bipyridines as risk factor. RESULTS: All pathology specimens showed various degrees of solar damage: early actinic change, solar lentigo, actinic keratosis (AK), AK coexisting with squamous cell carcinoma (scc), and scc. Six specimens from four workers were scc or scc in situ. Three of six scc showed the coexistence of AK. Of the workers, 133 had skin lesions ranging in severity from grade 1 to grade 3 on sun-exposed areas. The severity of skin changes is strongly associated with heavy exposure to bipyridines (P < 0.0001). CONCLUSION: This pathologic study proves that all the lesions showed either photodamage or skin cancer. The strong trend in the correlation between severity of photodamage and exposure to bipyridine leads to the speculation about the synergistic role of bipyridine exposure and the solar effect in causing these malignant and premalignant skin lesions.

Adult↗
PubMed1995

Cost and determinants of morbidity from work related disabling injuries in Taiwan.

OBJECTIVES: To estimate the cost and determinants of morbidity from work related disabilities. METHODS: 114 people who lived in metropolitan Taipei and who had received disability compensation from the Labor Insurance Bureau from March to June, 1991 were randomly selected. There were 77 workers interviewed through a questionnaire that inquired about possible loss of productivity including the duration of morbidity, the ability to return to work, and any change in monthly income upon returning to work. RESULTS: The mean (SD) duration of a stay in hospital was 29 (39) days, median: 15 days. The average duration between discharge from the hospital and returning to work was 111 (146) days, median: 45 days. The main determinants of the duration of the stay in hospital were the number of stays in hospital and the severity of the injury. A multivariate linear analysis showed that old age and the severity of injury determine the durations of morbidity. An ordinal logistic regression analysis showed that the severity of injury, size of the factory, and age determined the magnitude of future productivity loss. Based on these models, it was estimated that the total duration of morbidity (in hospital and at home) due to occupational disability was 660,000 person-days each year. When the percentage of the decrease in income because of permanent disability was converted into a loss of work days, the annual morbidity costs were about 19,000-26,000 person-years between 1985-1990. CONCLUSION: The morbidity cost was about five times as high as the lump sum payment that a worker usually received for disability compensation. We conclude that morbidity cost should be evaluated carefully in the future for the establishment of accurate and fair disability compensation payments.

Accidents, Occupational↗
PubMed1995

Combined electroneurographic and electromyographic studies in lead workers.

OBJECTIVES: To evaluate the effects of chronic exposure to lead on the peripheral nervous system in lead workers. METHODS: Nerve conduction velocity and electromyographic studies were performed on 31 lead workers of a battery recycling factory and 31 sex and age matched controls. 25 cases with mild distal extensor weakness of the upper limbs were classified as the lead neuropathy subgroup and the rest of the lead workers as the lead exposure subgroup. Blood lead concentrations and haematological and biochemical data were recorded. An index of cumulative exposure to lead was calculated by the summation of multiplying the average blood concentration of lead with the duration of exposure at various jobs. RESULTS: Compared with the control group, the distal motor latency of the median nerve was significantly prolonged in the lead neuropathy subgroup, but not in the exposure subgroup. Only six of 31 workers had nerve conduction abnormalities, whereas electromyographic evidence of denervation was found in 93.5% of the lead neuropathy subgroup and 83.5% in the lead exposure subgroup. The electromyographic abnormalities found were neurogenic polyphasic waves in all 29 workers with abnormal electromyographic findings (grade in seven cases and grade ++ in the rest). Spontaneous activity was only recorded in seven workers, with grade + in four and grade ++ in three. There was a positive linear correlation between the index of cumulative exposure to lead and the distal motor latencies of the tibial nerve as well as a negative correlation with conduction velocities of the sural nerve after multivariate analysis and control of potential confounding by age and sex. No correlation could be found between the electrophysiological values and a simple duration of exposure or concentration of blood lead. A non-parametric analysis showed that there was a trend of higher index of cumulative exposure to lead with more severe electromyographic changes. Electromyographic abnormality also occurred in workers with blood lead concentrations between 17.4 and 58 micrograms/dl. CONCLUSION: Electromyographic study in the distal extensors of the upper limbs may be used as a tool for biological monitoring of effect in lead workers.

Adult↗
PubMed1995

Cumulative injury rate and potential workdays and salary lost.

OBJECTIVES: The purpose of this study was to examine alternative methods for quantifying occupational injuries and to estimate the costs of foregone earnings due to these injuries. METHODS: A model based on the three possible outcomes of occupational injuries (premature death, permanent disability, and temporary dysfunction) was proposed, and several new indices were developed to measure the frequency and severity of occupational injuries. In the calculations, the human capital method was employed to measure potential salary lost due to occupational injury. An example was adopted from a steel corporation to demonstrate these indices. RESULTS: The cumulative injury rates, based on age and duration of employment, represented the average cumulative risk of acquiring occupational injuries by lifetime work duration and by employment duration, respectively. The severity index revealed the rate of estimated potential workdays lost by incorporating both the age at which an injury occurred and the severity weighting factors of various disabilities into the formula. After the estimated potential workdays lost was divided by the total employees' potential affordable workdays, the proportion of potential workdays lost showed a result that adjusted for the varied age distribution in each year implicitly. The potential loss in salary calculated the foregone earnings of occupational injuries, which could be considered as a lower limit of the monetary cost estimated by the willingness-to-pay method. CONCLUSIONS: Such indices supplement disabling frequency and severity rates. They cannot only be applied to occupational safety monitoring, but also to the policy-making process in occupational safety and health.

Adult↗
PubMed1995

[Papillary microcancer of the thyroid].

The aim of this study was to determine the outcome of patients operated for microscopic papillary cancer of the thyroid. Between 1962 to 1991, among 1103 patients operated for papillary thyroid carcinoma, 115 (11.5%) had a cancer with a diameter of 10 mm or less, no clinically detectable. 48 patients were diagnosed incidentally at the time of operation for other thyroid diseases, and 67 patients presented cervical lymph node metastases as the first sign. For patients diagnosed for other thyroid diseases, unilateral lobectomy with local neck dissection was performed in 35 cases, and in patients with cervical lymph node metastases unilateral lobectomy with locoregional neck dissection was performed in 56 cases. Mean overall follow-up was 12 years, and median follow-up time of 105 surviving patients was 10 years. 10-year survival rates were 100% in the patients diagnosed for other thyroid diseases, and 87% in patients with cervical lymph node metastases (P < 0.05). Out of 48 patients with no cervical lymph nodes, 44 were alive, and 4 died without recurrence or metastases. Out of the 67 patients with cervical lymph nodes, 5 died of the carcinoma. These results suggest that for patients diagnosed for other thyroid diseases, unilateral lobectomy with local neck dissection is sufficient, and for patients with cervical lymph node metastases unilateral lobectomy and locoregional neck dissection is necessary.

Adolescent↗