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Biomedical subjects

J D Wang

Publications and source records attributed to J D Wang.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Using genetic algorithm for quantitative analysis of overlapped spectra in FTIR].

Technique for the quantitative analysis of FTIR spectra, which are serious overlapped in the spectral bands, is studied by genetic algorithm. The multicomponent in the mixture, which contains ten air toxic organic components, such as benzene, phenixin, chlorobenzene, nitrobenzene, phenol, toluene, methanol, o-cresol, m-cresol and p-cresol, is simultaneously determined. The effect of the probability of crossover and the establishment of objective function are discussed. The method of adaptive mutation is used. The results indicate that genetic algorithm has excellent non-linear ability of solution. Mean relative error of each results is really small, generally not bigger than 1%, when the conditions are properly controlled.

Algorithms↗
PubMed2000

Subject-domain approach to the study of air pollution effects on schoolchildren's illness absence.

In this paper, the authors propose a new statistical modeling technique, the subject-domain approach, which is theoretically proven to be equivalent to the time-domain approach in detecting an association between exposure and response with time trends. The authors use an empirical data set from a school absence monitoring study conducted during the 1994-1995 school year in Taiwan to demonstrate this subject-domain approach's application to environmental epidemiologic studies. Because the subject-domain models can control the influential personal confounding factors in the models, they show greater statistical power than the traditional time-domain approaches in determining the relation between air pollution and illness absences. The authors' models found that the schoolchildren's risks of illness absence were significantly related to acute exposures to nitrogen dioxide and nitrogen oxides with a 1-day lag (p < 0.01) at levels below the World Health Organization's guidelines. By contrast, the authors could not detect significant associations between air pollution and schoolchildren's absenteeism using time-domain approaches. Such findings imply that the models built on subject domain may be a general solution to the problem of the ecologic fallacy, which is commonly encountered in environmental and social epidemiologic studies.

Absenteeism↗
PubMed2000

New affinity nylon membrane used for adsorption of gamma-globulin.

Microporous polyamide membranes were first modified by acid hydrolysis and subsequently bound with hydroxy-ethylcellulose to amplify reactive groups and reduce nonspecific interactions with proteins. Then 1,6-diaminohexane as space arm and phenylalanine as ligand were immobilized onto the nylon membranes by s-triazine trichloride activation. Affinity membranes thus obtained were set in a stack and used to adsorb gamma-globulin. The adsorption capacity (qm) of the affinity membrane is 53 micro gamma-globulin per m2 membrane and the desorption constant (Kd) is 2.35 x 10(-6) mol/l. The effects of feed, washing and elution rates on adsorption and desorption behavior were investigated. The results showed that affinity purification through these membranes could not be operated at very high flow-rates. A stack of 20 membranes with 47 mm diameter can adsorb 7.8 mg gamma-globulin with a purity of 91.6% from 4 ml of human plasma in a single-pass mode.

Adsorption↗
PubMed2000

A simple self-rating assessment method of residual work capability for occupational permanent disabilities.

BACKGROUND: To explore the validity, reliability, and determinants of a simple self-rating assessment method of residual work capability (RWC) after occupational permanent disabilities. METHODS: Five hundred and thirty-nine compensated permanent disability workers answered three consecutive visual analogue questionnaires wherein they self-rated their residual work capability in terms of speed (RWCS), quality (RWCQ) and a combination of speed and quality (RWCC). At two major hospitals in Taiwan, 169 of these subjects were evaluated with physical capacity assessment (PCA), cognition and sensation assessment (CSA), the work ability index (WAI), and the 12-item Chinese health questionnaire (CHQ-12). RESULTS: High test-retest reliability (Pearson's correlation coefficient 0.77) and satisfactory concurrent validity were shown for RWCS and RWCC. All PCA, CSA and WAI showed significant correlation with RWCs, while CHQ-12 displayed borderline correlation. Employment status after injury and status of the victim's salary as the main source of income for his/her family before injury, were the major determinants of RWCs, in addition to the scales of PCA, CSA and WAI. CONCLUSIONS: The RWCC resulting from the self-rating method may be used as a simple assessment of a victim's residual work capability after occupational permanent disabilities.

Accidents, Occupational↗
PubMed2000

Mother's willingness to pay for her own and her child's health: a contingent valuation study in Taiwan.

We use the contingent valuation (CV) method to estimate mothers' willingness to pay (WTP) to protect themselves and their children from suffering a minor illness-a cold-in Taiwan. WTP is specified as a hedonic function of the duration and severity of the cold (measured alternatively by symptoms experienced and the Quality of Well-Being (QWB) index) and of respondents' socioeconomic characteristics. The average mother is willing to pay more to protect her child than herself from suffering a cold. Median WTP to avoid the average mother's and child's colds are US$37 and US$57, respectively. Adjusting for the greater duration and severity of the average mother's cold suggests that WTP to prevent comparable illnesses is approximately twice as large for the child as for the mother. We also find that mother's WTP is about 20% greater to prevent a son's than a daughter's illness.

Adult↗
PubMed2000

Clinicopathological evaluation in non-episode biopsies of renal transplant allograft.

Histopathological findings in renal allograft with stable function remain unclear. We therefore performed non-episode biopsy in the long-surviving renal allograft to investigate the histopathological changes. Our data show that, although arteriolopathy is characteristic of drug-induced nephropathy, it is unrelated to dosage and concentration of cyclosporine or tacrolimus in non-episode biopsy. We evaluated therefore the clinicopathological findings of arteriolopathy in this study. Non-episode biopsy was defined as follows: as serum creatinine level lower than, 2.0 mg/dl and a urinary protein level lower than 500 mg/day. A total of 65 biopsy specimens were enrolled in this study as non-episode biopsy. Twenty-nine specimens revealed arteriolopathy. There were no statistically significant differences between arteriolopathy and dosage or concentration of cyclosporine or tacrolimus. Arteriolopathy in non-episode biopsy was related to time of biopsy, kidney age, hypertension, and hyperlipidemia, suggesting that it is important for graft survival to strictly control blood pressure and blood lipid level.

Adult↗
PubMed2000

Factors influencing vertebral bone density after renal transplantation.

To improve our understanding of the mechanisms underlying osteoporosis following renal transplantation, we compared bone mineral density (BMD) in 158 transplant recipients and in 293 patients undergoing maintenance hemodialysis with age- and sex-matched normal controls. Observations in graft recipients were made up to several years following transplantation. Dual-energy X-ray absorptiometry was used to measure BMD. Correlations with clinical variables including serum concentration of parathyroid hormone (PTH) and steroid therapy were evaluated. Lumbar BMD was lower in transplant patients than in dialysis patients at all ages, and continued to decrease with increasing interval posttransplant until the second year after transplantation. Persistent hyperparathyroidism and daily prednisolone dosage were both associated with decreased BMD. Age and creatinine clearance were independent long-term predictors of BMD by multiple regression analysis. Treatment of renal graft recipients with calcium and vitamin D supplements or calcitonin may be indicated in the early months after transplantation.

Absorptiometry, Photon↗
PubMed2000

Differences in binding of glucocorticoid receptor to DNA in chronic renal graft rejection.

Although chronic rejection is the most common reason for late allograft loss, its pathophysiology and etiology are unclear. Attempts to prevent chronic rejection are now focused on the modulation of transcriptional regulation. We evaluated the ability of glucocorticoid receptors (GR) to bind to the DNA binding site in peripheral blood mononuclear cells (PBMC) of five patients with chronic rejection and seven without it. Using an electrophoretic mobility shift assay, we measured the amount of nuclear glucocorticoid receptor capable of binding to its specific DNA recognition sequences, termed glucocorticoid response elements (GRE). GR binding was significantly greater in control patients than in those with chronic rejection (P < 0.01). The retarded band was almost undetectable in two patients with chronic rejection even though they were taking more prednisolone than the seven control patients, all of whom had clearly identifiable retarded bands. These results suggest a decreased ability of GR to bind to GRE in chronic rejection, resulting in a reduced ability to block key proinflammatory promoter sites. This reduced binding may be one molecular basis of chronic rejection.

Adult↗
PubMed2000

Diagnosis and monetary quantification of occupational injuries by indices related to human capital loss: analysis of a steel company as an illustration.

Prevention of occupational injuries is an important task of human resource management. In this study, new indices of human capital loss of occupational injury including cumulative injury rate, proportion of potential workdays lost, and potential salary lost were applied to the analysis of registry data of occupational injuries from 1986 to 1994 of a steel company in Taiwan. In addition, we compared these indices with disabling frequency rate and severity rate. The results showed that the average disabling frequency rate and cumulative injury rate of the whole company were 4.12 and 0.41, respectively; and the average disabling severity rate and proportion of potential workdays lost of the whole company were 563 and 229 x 10(-6), respectively, during 1986-1994. There was no consistent improvement in occupational safety in this period. The average potential salary lost of the whole company was more than US$ 2 million per year with a discount rate of 0.04, which was equivalent to 92 times of average annual income of a worker. The major monetary loss were due to non-traffic injuries of operators and traffic injuries of non-operators, which amounted to US$ 145 and 152 per person per year. As the new indices can provide additional information on lifetime occupational risk and human capital loss in monetary values, we concluded that they may be useful supplementary tools for monitoring and analyzing occupational injury data in a company.

Accidents, Occupational↗
PubMed2000

Oligosaccharides from Hoya carnosa.

Oligosaccharides A, B, and C (1-3, respectively) were isolated from the stem of Hoya carnosa. Their structures were established by NMR and chemical methods. Compounds 1 and 2 were 6-deoxy-3-O-methyl-beta-allopyranosyl(1-->4)-beta-cymaropyranosyl( 1-- >4)-beta-cymaropyranosyl(1-->4)-beta-cymaronic acid delta-lactone and 6-deoxy-3-O-methyl-beta-allopyranosyl(1-->4)-beta-oleandropyranosyl++ +(1 -->4)-beta-cymaropyranosyl(1-->4)-beta-cymaronic acid delta-lactone, respectively. Compound 3 was the sodium salt of 2.

Carbohydrate Conformation↗
PubMed2000

Arteriolopathy in non-episode biopsies of renal transplant allograft.

PURPOSE: We have been performing protocol biopsies since 1995 to predict the outcome of renal allograft. However, histopathological findings in renal allograft with stable function remain unclear. For this reason, we performed non-episode biopsy on long-surviving renal allograft and investigated the histopathological changes. Among the several diseases seen in non-episode biopsies, arteriolopathy, such as drug-induced nephropathy, is one of the most frequent diseases. However, it is unrelated to the dosage and the concentration of cyclosporine or tacrolimus. Consequently, we evaluated the clinicopathological findings of arteriolopathy in this study in order to clarify whether cyclosporine (CsA) or tacrolimus (FK506) is responsible for these findings. MATERIALS AND METHODS: We defined non-episode biopsy as a case with a serum creatinine level less than 2.0 mg/dL and containing less than 500 mg/dL of urinary protein. Final results showed that 71 cases were identified as non-episode biopsy. We then evaluated the histopathological findings and the clinical characteristics of these cases. RESULTS: Thirty-two of the 71 non-episode biopsy specimens showed findings of arteriolopathy. The frequency and the severity of arteriolopathy are not concerned with dosage and concentration of CsA or FK506. The arteriolopathy seen in non-episode biopsy was related to the time of the biopsy and the kidney age. Arteriolopathy in nonepisode biopsy also had a relationship with hypertension, suggesting that it is important to strictly control blood pressure for graft survival.

Adult↗
PubMed2000

Dimethylacetamide, ethylenediamine, and diphenylmethane diisocyanate poisoning manifest as acute psychosis and pulmonary edema: treatment with hemoperfusion.

CASE REPORT: A 27-year-old man, employed by a synthetic fiber company, had been exposed to dimethylacetamide, ethylenediamine, and diphenylmethane diisocyanate in a confined space continuously for 4-6 hours per day for 3 days before admission. Hallucinations and delusions were noted at admission; pulmonary edema developed subsequently. The electroencephalogram showed diffuse moderate cortical dysfunction and slow waves at 4-7 Hz, 20-80 microV. Seizures, liver injury, and rhabdomyolysis were noted on the 4th hospital day. The patient was treated by hemoperfusion with a decrease in urine dimethylacetamide from 3,265 mg/g to 4 mg/g creatinine over 4 days. Serial urinary dimethylacetamide and electroencephalogram correlated with the clinical condition.

Acetamides↗
PubMed2000

Vibration perception thresholds in workers with long term exposure to lead.

OBJECTIVES: To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter. METHODS: 217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT. RESULTS: VPT at a frequency of 220 Hz ranged from 6 to 100 (10(-2) g, or 0.098 m/s(2)) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 microgram/dl. Above this threshold it was estimated that each increase of 1 microgram/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10(-2) g) or 0.028 m/s(2) (at a frequency of 220 Hz) with other potential confounders held constant. CONCLUSION: This study suggests that measurement of vibration sensory threshold is a relatively effective tool for detecting lead neuropathy in field studies, and that lead might cause sensory neuropathy with an effect threshold corresponding to a 5 year mean blood lead concentration of 31 microgram/dl.

Adult↗
PubMed2000

[Renovascular hypertension].

Renovascular disease is one of the most common causes of secondary hypertension. Recent technical advances have changed the management principles, which include a more aggressive approach to the diagnosis and treatment of renovascular hypertension (RVH). We experienced a total of 95 cases with RVH between 1958 and 1999. The mean age of all patients was 31.8 years old, ranging from 3 to 64 years. The three major basal diseases that caused RVH were fibromuscular dysplasia (34/95), arteriosclerosis (26/95), and aortitis (12/95). Ninety-two kidneys were treated in 79 of the 95 patients. The major therapeutic modalities performed were reconstruction of renal artery (6/79), nephrectomy (21/79), autotransplantation (26/79), and percutaneous transluminal angioplasty (PTA) (25/79). PTA is now the treatment of choice for the initial management of patients with RVH. Surgical treatment is generally reserved for patients in whom PTA fails. Pharmacotherapy is used on patients awaiting angioplasty or revascularization, those who are too ill for intervention, and those who have failed to respond to intervention.

Adolescent↗
PubMed2000

[Recent advances of silica packing in high performance liquid chromatography].

Developments of silica packings in high performance liquid chromatography are reviewed with 65 references. Preparative and modification methods of silica packings are introduced. The physical characterization on silica surface is elucidated. The applications of silica packings in HPLC are outlined and the trends of silica packings in China are described.

Chemical Phenomena↗
PubMed1999

Monte Carlo estimation of extrapolation of quality-adjusted survival for follow-up studies.

The expected quality-adjusted survival (QAS) for an index population with a specific disease can be estimated by summing the product of the survival function and the mean quality of life function of the population. In many follow-up studies with heavy censoring, the expected QAS may not be well estimated due to the lack of data beyond the close of follow-up. In this paper, we first created a reference population from the life tables of the general population according to the Monte Carlo method. Secondly, we fitted a simple linear regression line to the logit of the ratio of quality-adjusted survival functions for the index and reference populations up to the end of follow-up. Finally, combining information on the reference population with the fitted line, we predicted the expected quality-adjusted survival curve beyond the follow-up period for the index population. Simulation studies have shown that the simple Monte Carlo estimation procedure is a potential approach for estimating expected QAS and the survival function beyond the follow-up with a certain degree of accuracy.

Computer Simulation↗
PubMed1999

Early induction of apoptosis in androgen-independent prostate cancer cell line by FTY720 requires caspase-3 activation.

BACKGROUND: We previously reported that FTY720, a metabolite from Isaria sinclairii, induced some cancer cells to undergo apoptosis, and that FTY720-induced apoptosis was not related to Fas-antigens. In this study we investigated whether FTY720 was able to induce apoptosis in an androgen-independent prostate cancer cell line, DU145, which is not only resistant to androgen-withdrawal-induced apoptosis but also Fas- and TNF-alpha-mediated apoptosis. METHODS: Cell survival and morphological change were examined and apoptosis was confirmed by DNA isolation and analysis of DNA fragmentation. Caspase activation was studied by using anti-caspase-1 and anti-caspase-3 antibodies. To determine whether caspase activation is central to FTY720-induced apoptosis, caspase inhibitor was added to the media 24 hr prior to the addition of FTY720. RESULTS: We found that FTY720 rapidly induced apoptosis in DU145 cells, and that caspase-3 was activated during FTY720-induced apoptosis. In contrast, normal human prostate stromal cells were resistant to FTY720. Furthermore, FTY720-induced apoptosis was prevented by caspase-3 inhibitor. CONCLUSIONS: The data in this report show that FTY720 is a potential strong antitumor agent for cell line DU145, and provide the first evidence for involvement of caspase-3 in apoptosis of an androgen-independent prostate cancer cell line. Activation of such caspases may provide a means for eliminating androgen-independent prostate cancer in humans.

Androgens↗