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Biomedical subjects

J D Wang

Publications and source records attributed to J D Wang.

At least 109 records · Page 6Linked to original sources
PubMed1994

Increased lead absorption caused by working next to a lead recycling factory.

The objective of this study was to determine whether workers at a factory in Taiwan, adjacent to lead recycling plant, were affected by lead contamination. Workers at the lead recycling plant itself were found to suffer from lead poisoning; air and soil outside the plant were heavily contaminated by lead. Forty-one of the 45 workers in a forging factory next to the lead recycling plant were enrolled as the exposed group. A comparison group of 51 workers were selected from another forging factory about 20 km away. Each subject was interviewed about his lifestyle, work history, and residence, and blood was drawn for lead measurement by graphite furnace atomic absorption spectrometry. The results showed that two groups were compatible in age, sex, and smoking patterns. Blood lead of the exposed group was significantly higher than that of the comparison group (mean +/- SD: 20.4 +/- 9.4 micrograms/dl vs. 5.9 +/- 2.9 micrograms/dl). The difference was independent of sex and working zones. Blood lead levels were lower among exposed workers who had been employed less than 2 months compared with those employed longer. There was no difference among exposed workers in different outdoor working zones. Five months after improvement of pollution control and decrease in the production volume of the lead factory, 30 exposed workers were retested for blood lead. The blood lead of outdoor workers had an average decrease of 4.2 micrograms/dl while that of indoor workers showed no significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental Exposure↗
PubMed1994

Tissue and serum levels of steroid hormones and RU 486 after administration of mifepristone.

The present study was designed to examine the effect RU 486 administration on steroid hormone levels in serum and decidua. Sixty women at 6-7 weeks gestation were divided into three groups. The first group took a placebo 24 hours before interruption of pregnancy. The other two groups took 200 mg mifepristone 12 and 24 hours before the surgical procedure, respectively. The concentrations of steroids and mifepristone were measured by radioimmunoassay or high performance liquid chromatography. Mifepristone treatment increased the levels of estradiol, cortisol and testosterone in serum and decidual cytosol (p < 0.05 or p < 0.01). A minor elevation in progesterone level was observed but was not statistically significant. The tissue levels of progesterone, estradiol and testosterone were much higher than the serum levels, whereas RU 486 concentration in the tissue was only one-third of the serum level. In addition, the RU 486 level in decidual cytosol was of the same order as that of progesterone. This competitive concentration was not achieved in chorionic villi in our previous observation, explaining why mifepristone exerts its predominant effect on decidua rather than villi. It is concluded that RU 486 reached an effective inhibitory concentration in decidua and had significant effects on the endocrine milieu.

Abortion, Induced↗
PubMed1994

Immunocytochemical colocalization of progesterone receptor and prolactin in individual stromal cells of human decidua.

Progesterone stimulates decidual PRL production. However, decidualized tissue, in which a high level of PRL is present, features a relatively low level of progesterone receptor (PR) expression. The discrepancy has to be explored at the individual cell level. The present study employed a double labeling method to colocalize PR and PRL in human decidua to examine the correlation between these two proteins. In frozen sections, decidual stroma presented two kinds of cell, which differed in PRL staining. Decidualized cells were positively stained with PRL in cytoplasm and displayed a large cell size and a clear cell outline. Nondecidualized cells showed no specific PRL staining and no clear cell boundary. In decidual stroma, PR staining was exclusively localized in the nuclei, with variations in intensity. When double staining with PR and PRL was performed, these two types of cells demonstrated diverse staining patterns. The PRL-producing cells exhibited weak PR staining, whereas PRL-negative cells evidenced stronger PR staining. In RU 486-treated samples, decidual stroma became less stained with PRL, compared with the control, and fewer cells displayed typical morphology of decidualization, whereas PR staining in the tissue became more extensive and intensive. Double labeling disclosed that the cells with enhanced PR staining were coupled to weaker PRL immunoreaction. Our data suggested an inverse relationship between PRL and PR in individual stromal cells in vivo, which could be reversed by antiprogestin treatment. A possible autocrine mechanism controlling this phenomenon was proposed and deserves further study.

Cell Nucleus↗
PubMed1994

[Analysis of 28 clinical cases and bone in stress around every tooth with pericementitis caused by occlusal trauma]

28 cases of pericementitis on occlusal trauma were observed,treated and followed up for 2 years;The bone in stress around every involved tooth was analysed according to the stress analysis by three demensinal photoelastic models loading excessive occlusal forces in various direction and coincided with the area of abnormality on the tooth radiograph.The result showed that the present methods of examination and treatment for tooth with traumatic pericementitis could diagnose exactly and cure effectively this disease;the rate of cure for 2 years was 86.7%,subtle occlusal adjustment by 3-4 appointments could maintain stable curative effect.It is suggested that clinicians should pay more attention to discover and treat both with traumatic pericementitis,the earliest clinical manifestation of both injury in occlusal trauma in order to protect them from severe injury in occlusal disharmony as well as periodontal trauma.

Journal Article↗
PubMed1994

[Head injuries in traffic accidents with emphasis on the comparisons between motorcycle-helmet users and non-users].

Motor-vehicle incidents in Taiwan are a major cause of head injuries. Our objective was to analyze the characteristics of head injuries caused by motor vehicle accidents in terms of the injured person's demographic characteristics, time and types of crash, injury severity on the abbreviated injury scale (AIS), medical cost and benefits of helmet protection. For this purpose we conducted an epidemiologic survey of 2451 consecutive victims of traffic accidents, coming to, or managed at, the emergency care department of a large Taipei metropolitan hospital in 1990. The results showed that the most common cause of head injury in traffic accidents was a motorcycle incident. Motorcycle accident injured patients were generally young males, laborers or students. Most head injuries occurred between 16:00 and 23:00, and peaking at 21:00 in a day. Forty-three points four percent of patients were admitted, major head injury fatalities occurred within one week of the collision. The elderly or patients with high AIS comprised most nonsurvivors. According to our data, helmet usage was about 14% overall. Helmetless young riders were numerous among the total victims. A significant difference was noted in the severity of injury of helmeted users of motorcycles, compared with those who wore no helmet. As expected, patients who did not wear a helmet had a greater AIS average and higher rate of fatality. Forty-one of the 42 fatalities were patients who had been riding on motorcycles without helmets. Helmets provide adequate protection and reduce severity of injury, and medical cost for motorcycle collisions.

Accidents, Traffic↗
PubMed1994

[Epidemiologic analysis of 845 cases of pedestrian traffic injuries].

BACKGROUND: Pedestrian-vehicle collision is a serious public health problem today in Taiwan, but this issue of pedestrian safety has received relatively little attention. The purpose of this study was to evaluate the characteristics of pedestrian injury after involvement in a collision. METHODS: An epidemiologic study on 845 traffic accident consecutive victims, managed at Tri-Service General Hospital in 1990, was performed. They were interviewed with a brief questionnaire about demographic data and types of accident including injured site, Injury Severity Score (ISS) and outcome; the latter was obtained by review of medical records and by a telephone survey performed four months after discharge. RESULTS: Results showed a common distribution of injuries for all age groups. Of the 845 patients, 487 were male and 358 were female (sex ratio = 1.4:1). The majority of injuries (84.8%) occurred for pedestrians who were walking on the side of, or crossing, the road. Four hundred and ninety-six victims (58.7%) were treated in the Emergency Department only, while 342 patients (40.5%) were further admitted as inpatients; the remaining 34 patients (4.0%) died in the Emergency Department (0.8%), or as inpatients (3.2%). The study showed fatality rates according to age as follows: 0.5% age 1 to 19, 1.8% age 20 to 39, 4.6% age 40 to 59, 7.5% age 60 or older, with the elderly having the highest pedestrian death rate. Elder pedestrians who were struck by motor vehicles also had the highest fatality rate of all pedestrian injury victims. The percentage of pedestrian injuries is fairly constant from month to month. For time of day, 12 noon and 3 to 5 pm were associated with the most injuries for age 0-19 youths; 4 pm and 10 pm for age 20-59 adults; 8 am and 7 pm for age 60 or older. There was a significant difference of mean ISS between the nonsurvivors (27.8) and the survivors (4.6) (p < 0.01). When nonsurvivors were compared with survivors, among the aged (> 60), high Abbreviated Injury Scale (AIS) of head, and high ISS were most common among nonsurvivors (p < 0.01). CONCLUSIONS: That pedestrians are the least protected participants in traffic. Situations is reflected by a considerable fatality rate among pedestrians. Data from this study should be useful for designing, implementing, and evaluating a targeted pedestrian safety program in Taiwan.

Accidents, Traffic↗
PubMed1993

Acute and chronic neurological symptoms among paint workers exposed to mixtures of organic solvents.

The purpose of this study was to determine the prevalence rates of acute and chronic neurologic symptoms among paint workers and the association of such symptoms with the severity of exposure to mixtures of solvents. Two paint manufacturing factories and 25 various kinds of spray painting factories were selected for study. Air concentrations of organic solvents were measured by personal samplers and were analyzed by gas chromatography. A total of 196 workers were given a screening neurological examination and a questionnaire on acute and chronic neurologic symptoms. A detailed personal medical history and a profile on alcohol consumption and medication were also included. The results showed that xylenes and toluene were the major solvents found in almost all the air samples with average contents of 50 and 24% on a weight basis of 73 air samples. We classified workers according to different exposure patterns and different air concentrations of breathing zones: high (8-hr hygienic effect, 0.25-9.86; median, 1.66), short-term high (hygienic effect, 0-3.38; median, 0.12), and low (hygienic effect, 0-0.38; median, 0.12). All workers showed no overt neurological signs such as ataxic gait, poor coordination, or muscle weakness. After excluding those workers who consumed more than 280 g of alcohol per week (n = 8), took antihypertensive medications (n = 4), or were treated with antipsychotic agents (n = 1), we found that the severity of exposure was associated with acute symptoms of headache and chest tightness and chronic symptoms of dizziness, easy fatigability, depressed mood, and palpitation. There was no association between peripheral neurological symptoms and the severity of exposure. Workers in the high exposure group were 2.7 times more likely to develop two or more acute symptoms and 3.3 times more likely to develop three or more chronic symptoms of the central nervous system than the low exposure group. After modeling by multiple logistic regression, we concluded that exposure to a medium level of mixtures of solvents (hygienic effect exceeding 1.66) may produce acute and chronic central neurological symptoms.

Acute Disease↗
PubMed1993

Estrogen and progesterone receptors in human decidua after RU486 treatment.

OBJECTIVE: To examine RU486 action on decidua at the level of cellular estrogen receptor (ER) and P receptor (PR). DESIGN: Controlled basic study for contragestion mechanism of mifepristone. SETTING: Normal human volunteers in an academic research environment. PATIENTS: Sixty women with 6 to 7 weeks of gestation who voluntarily requested termination of pregnancy were recruited and randomly divided into three groups. INTERVENTION: A single dose of 200 mg RU486 was orally administered to the two treatment groups 12 and 24 hours, respectively, before surgical interruption of pregnancies. Placebo was used for control group. Decidual tissues were collected right after operation. MAIN OUTCOME MEASURE: Immunocytochemical reactions of PR and ER in decidua after RU486 treatment were compared with the control subjects. The differences of the reaction in decidual area with or without trophoblast invasion were noted. RESULTS: RU486 treatment increased PR and ER staining in vessel and stroma of decidua without trophoblast invasion (decidua parietalis) but not in decidua with trophoblast invasion (decidua capsularis or basalis). Chi-squared analysis indicated a significant increase in the number of ER-positive samples after RU486 treatment. CONCLUSION: The decidua parietalis was the primary target site of RU486. The lack of RU486 effect on decidua capsularis implied that trophoblast invasion prevented against antiprogestin impact.

Abortion, Induced↗
PubMed1993

Occupational exposure to 4,4'-bipyridyl vapor and aerosol during paraquat manufacturing.

The mass concentrations of both vapor and aerosol phases of 4,4'-bipyridyl were determined by a glass fiber filter and an XAD-2 tube in a paraquat factory. The size distributions of 4,4'-bipyridyl aerosols and particles < 10 microns were measured by a six-stage cascade impactor. The mass concentrations of 4,4'-bipyridyl aerosols were in the range of 81.9 to 159.9 mg/m3 with an average 4,4'-bipyridyl vapor mass concentration of 3.1 mg/m3 at the top of the open tank. On the average, the mass ratio of vapor phase to aerosol phase of 4,4'-bipyridyl was 0.025. Therefore, the aerosol phase is the major form of 4,4'-bipyridyl exposure to the workers in this environment. From the 4,4'-bipyridyl concentrations measured by the sampling systems of an XAD-2 tube alone and a filter followed by an XAD-2 tube, the 4,4'-bipyridyl aerosol collection efficiency of the XAD-2 tube was found to be approximately 50%. The average mass concentrations of less than 10 microns aerosols and 4,4'-bipyridyl aerosol in the occupational environment were 0.42 mg/m3 and 1.26 micrograms/m3, respectively. The mass median aerodynamic diameter (geometric standard deviation) of particles < 10 microns and 4,4'-bipyridyl aerosol are 3.50 microns (2.35) and 3.47 microns (2.58), respectively. The major mass fraction of 4,4'-bipyridyl aerosol occurred in the 3.3-5.8 microns size range. The enclosure efficiencies of a hood cover attached to a suction tube were found to be 88% and 82% for both aerosol and vapor phases of 4,4'-bipyridyl, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants, Occupational↗
PubMed1993

The effect of RU 486 on progesterone receptor in villous and extravillous trophoblast.

A total of 60 women with 6-7 weeks' amenorrhoea were randomly allocated to three groups. The women in the first group (control) took a placebo 24 h before undergoing vacuum aspiration. The subjects in the second and third groups were given orally 200 mg of RU 486, 12 or 24 h before surgical interruption of their pregnancy. Villi and decidua were collected and frozen in liquid nitrogen. There were no significant differences in villous cytosolic steroid concentrations between the control and RU 486-treated groups. The RU 486 concentration was lower in villous cytosol than in decidua and serum. The immunostaining of progesterone receptor in villous and extravillous trophoblast was weak and localized in both cytoplasm and nucleus. RU 486 treatment had no effect on the immunostaining of progesterone receptors in trophoblast populations except in the placental bed giant cells, where the weak and diffuse progesterone receptor staining in the cytoplasm of controls seemed to be concentrated in the nucleus after RU 486 treatment. In conclusion, RU 486 might have no effect on the immunostaining of progesterone receptor and on steroid concentrations in villi in vivo.

Chorionic Villi↗
PubMed1993

Primary infections of Epstein-Barr virus, cytomegalovirus, and human herpesvirus-6.

A total of 121 infants entered a cohort serological study of primary infections with herpes-viruses. All of them had seven samples of blood available: the first sample was taken soon after birth, the other six were taken at 1, 2, 3, 6, 12, and 14 months of age. One sample of maternal blood was collected immediately after delivery. All blood samples were tested for antibodies against cytomegalovirus, Epstein-Barr virus, and human herpesvirus-6 (HHV-6). Primary cytomegalovirus infection occurred early; the cumulative infection rates were 1.7%, 8.3%, 18.3%, 25%, 52.5%, and 65% by the ages of 1, 2, 3, 6, 12, and 14 months, respectively. Epstein-Barr virus infection was not seen before 3 months of age and slowly emerged thereafter, reaching a cumulative rate of 1.7%, 11.6%, 21.5% at the ages of 6, 12, and 14 months, respectively. Primary HHV-6 infection was also a rare event in the first three months of life, but peaked between 6 and 12 months of age. No detectable risk factors were associated with primary Epstein-Barr virus or HHV-6 infection. The risk factors associated with cytomegalovirus infection included breast feeding, fewer children in household, and care by a babysitter.

Age Factors↗
PubMed1993

[Estimation of case fatality rate and incidence rate of traffic injury in Taiwan--analysis of 4,329 victims at a medical center].

Accidents remain the third leading cause of mortality in Taiwan, of which traffic injuries constitute the major part. In order to characterize traffic injuries and to estimate the annual traffic injury rate in Taiwan, we conducted an epidemiologic study of 4,329 consecutive traffic accident victims, managed at the Tri-Service General Hospital from January to December of 1990. Victims were interviewed for demographic data and types of accident using a brief questionnaire. The questions included injury site and Injury Severity Score (ISS); final diagnosis and outcome were obtained by review of medical records and by a telephone survey performed 4 months after discharge. The sex- and age-specific case fatality rates calculated from the data obtained in this study were used to divide the annual incidence of traffic mortality abstracted from the vital statistics of Taiwan (1990) and, thus, to obtain an annual frequency of traffic injury cases under certain assumptions. The results showed that more men than women were injured in all age groups. The highest frequency of traffic injuries was noted in patients ranging in age from 20 to 39 years. Up to 58.9% of the victims were motorcycle users, followed by pedestrians (19.5%) and automobile-users (16.0%). The case fatality rate was 2.5% for males and 1.7% for females. The estimated annual traffic incidence was about 330,000, and the total annual rate of traffic injuries in Taiwan was 1,627/100,000 (2,188/100,000 for men and 1,114/100,000 for women).(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗
PubMed1993

[One year follow-up study of the recovery of adrenal insufficiency induced by formulated herb drugs].

Previous studies have found that taking formulated herb drugs may reduce the serum cortisol level which may result in an adrenal insufficiency. We suspect that this effect is induced by corticosteroids artificially mixed in formulated herb drugs. The objectives of this study were to determine the time course of serum cortisol and plasma ACTH (adrenocorticotropic hormone) levels, and whether pituitary-adrenal function recovers after quitting formulated herb drugs for a period of one year. Forty eight subjects with an initial serum cortisol level smaller than 10.7 micrograms/dL due to the intake of formulated herb drugs were recruited. They were tested for serum cortisol and plasma ACTH levels at 08:00 6, 9 and 12 months after quitting formulated herb drugs, respectively. The diagnosis of adrenal insufficiency was confirmed by an ACTH test at 9 months and 12 months after quitting the formulated herb drugs. The follow-up rates ranged from 63% to 71%. The 08:00 serum cortisol levels at the initial test, 6 months, 9 months, and 12 months were 4.4 +/- 0.5 micrograms/dL, 6.6 +/- 0.8 micrograms/dL, 6.6 +/- 0.7 micrograms/dL, 6.2 +/- 0.8 micrograms/dL, respectively, (interpersonal p = 0.0001, intrapersonal p = 0.0004, repeated measures ANOVA test.) The 08:00 plasma ACTH levels at the initial test, 6 months, 9 months and 12 months were 33.8 +/- 6.4 pg/mL, 67.6 +/- 16.8 pg/mL, 21.0 +/- 3.2 pg/mL, 16.3 +/- 2.2 pg/mL, respectively (interpersonal P = 0.0001, intrapersonal P = 0.0003, repeated measures ANOVA test.) The statistical significance was the same after logarithmic transformation of the ACTH levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗