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Biomedical subjects

W C Lee

Publications and source records attributed to W C Lee.

At least 127 records · Page 7Linked to original sources
PubMed1998

Risk of leukemia in children living near high-voltage transmission lines.

We conducted a study to examine the risk of leukemia between 1987 and 1992 among children living near high-voltage transmission lines (HVTL) in three urban districts of northern Taiwan. Twenty-eight cases of leukemia among some 120,696 children aged 14 years or less were reported to the national cancer registry between 1987 and 1992. Compared with children living in households more than 100 meters away from HVTL, children living in households less than 100 meters from HVTL experienced an essentially elevated risk of leukemia (7 versus 2.88, standardized incidence ratio [SIR] = 2.43, 95% confidence interval [CI] = 0.98-5.01). The elevated risk stands when compared with all children of Taiwan alternatively (7 versus 2.60, SIR = 2.69, 95% CI = 1.08-5.55). Such elevated risk was particularly noteworthy among children aged 5-9 years. The findings suggest that children living near HVTL tend to experience an elevated risk of leukemia. Further investigations are undoubtedly needed to unveil whether such tendency may have implied the putative association between exposure to elevated magnetic fields and risk of childhood leukemia.

Adolescent↗
PubMed1998

Underregistration of neonatal deaths: an empirical study of the accuracy of infantile vital statistics in Taiwan.

STUDY OBJECTIVE: The accuracy of the official statistic on infant deaths in Taiwan has been questioned. This study aimed to survey infant deaths nationwide, to measure associated vital statistics, and compare them with the official statistics to assess accuracy. DESIGN AND PARTICIPANTS: A nationwide survey of all gestational outcomes occurring at > or = 20 weeks' gestation over a three day study period (15-17 May 1989) was conducted to collect data from 23 counties and cities nationwide using a two stage data collection procedure. MAIN RESULTS: The survey derived infant death rate was 9.72 per 1000 live births, which was higher than the reported official statistic of 5.71 per 1000 live births. A more detailed examination of data on infant deaths showed that the estimated neonatal death rate of 6.68 per 1000 live births (95% confidence intervals: 3.33, 11.96 per 1000 live births) was significantly higher than the published official statistic of 1.94 per 1000 live births, while the postneonatal mortality of 3.04 per 1000 live births was comparable to the reported statistic of 3.37 per 1000 live births. CONCLUSIONS: This study empirically documented the underregistration of infant deaths in Taiwan, particularly those occurring during the first 27 days of life.

Data Collection↗
PubMed1998

Effect of melatonin on cadmium-induced hepatotoxicity in male Sprague-Dawley rats.

Effect of melatonin on toxicity of cadmium (Cd) was studied in male SD rats co-administered daily Cd (1 mg/kg b.w., s.c.) with melatonin (10 mg/kg b.w., i.p.) for 15 days. Cd alone injection decreased GSH concentrations in the liver and RBC by 35% and 43% compared with those in saline-treatment group, but not in the kidney and whole brain. The activity of GSSG-reductase was significantly decreased in the liver of Cd alone injected rats, while melatonin given in combination with Cd failed to prevent the Cd-induced decreased activity of hepatic GSSG-reductase. However, the hepatic GSH concentration decreased by Cd alone was restored by melatonin treatment, and the melatonin also ameliorated Cd-induced histopathological changes in the liver. Therefore, data indicate that melatonin restores the reduction of hepatic GSH level induced with Cd regardless of GSSG-reductase activity, and suggests that melatonin may ameliorate Cd-induced hepatotoxicity.

Animals↗
PubMed1998

The clinical significance of hyperamylasemia in organophosphate poisoning.

OBJECTIVE: Hyperamylasemia with a presumptive diagnosis of acute pancreatitis has been reported following organophosphate poisoning but there are no large-scale studies incorporating more specific diagnostic criteria. METHODS: Retrospective review of the medical records of 159 patients with a diagnosis of organophosphate poisoning over 3 years. Serum amylase, pancreatic amylase, salivary amylase, lipase and cholinesterase levels, and the clinical manifestations were analyzed. RESULTS: Serum amylase data was available for 121 of the 159 study patients. Hyperamylasemia (amylase > or = 360 U/L) was found in 44 patients (36%). Lipase was measured in 28 patients with hyperamylasemia; 9 of 28 had hyperlipasemia (lipase > or = 380 U/L). The finding of hyperamylasemia was closely related to clinical severity and presence of shock. A presumptive diagnosis of painless acute pancreatitis was diagnosed by hyperlipasemia associated with hyperamylasemia, clinical severity, serum LDH, and leukocyte counts. Two patients with presumptive pancreatitis died. Shock, coma, and hypoalbuminemia were the factors predicting fatality. CONCLUSIONS: Hyperamylasemia is frequent in severe organophosphate poisoning. However, hyperamylasemia is not synonymous with acute pancreatitis and pancreatic amylase is not a reliable parameter in the diagnosis of organophosphate-induced pancreatitis due to its low sensitivity and specificity. Lipase assay is indicated in patients with hyperamylasemia for early diagnosis of pancreatitis. Proper image studies and even pathological examination are also needed to confirm the extent of pancreatic injury. With prompt diagnosis and appropriate treatment, a complete recovery can be anticipated unless the patient has otherwise unrelated complications.

Acute Disease↗
PubMed1998

Sex difference in the mortality trends of acute myocardial infarction in Taiwan, 1974 to 1993.

The mortality patterns of coronary heart disease (CHD) vary among countries. Although the mortality rates from this disease are decreasing in the majority of developed nations, most developing countries are experiencing upward trends, especially among men. The mortality trends of acute myocardial infarction (AMI) in Taiwan have not been reported. The purpose of this study was to investigate the effects of age, chronicle period, and birth cohort on the AMI mortality rates using computerized vital statistics data from 1974 through 1993. Compared with the age-adjusted AMI mortality rates in 1974, the mortality rates in 1993 were 2.4 times higher for men and 2.2 times higher for women. When the log-linear Poisson model was used to assess age, birth cohort, and chronicle period simultaneously, women had no elevated relative risk of dying from AMI in different periods. The relative risk of dying from AMI increased 2.5 times for men in the 1955-1959 birth cohort compared with those in the 1890-1894 birth cohort, while the relative risk for females declined by 3.7 times for the corresponding birth cohorts. Based on birth cohort, the trends in mortality differ substantially between sexes in Taiwan. These results may help to generate hypotheses regarding the possible factors, prevention, and control of mortality from AMI in Taiwan.

Adult↗
PubMed1997

Protein separation using non-porous sorbents.

This article overviews the development of non-porous sorbents having small particle diameters which have proven effective for rapid analysis and micropreparative separation of proteins by liquid chromatography. Much attention is given to the preparation and application of silica- and polystyrene-based non-porous packings for various chromatographic modes, especially affinity chromatography. Modeling works on the prediction and parameter estimation for the dynamics of protein adsorption using non-porous sorbents are reviewed and briefly described. To conclude this review, future prospects of the application of non-porous sorbents are also presented.

Chromatography, Liquid↗
PubMed1997

Transforming activity and mitosis-related expression of the AKT2 oncogene: evidence suggesting a link between cell cycle regulation and oncogenesis.

The AKT2 oncogene encodes a protein-serine/threonine kinase containing a pleckstrin homology domain characteristic of many signaling proteins. Recently, it was shown that AKT2 kinase activity can be induced by platelet-derived growth factor through phosphatidylinositol-3-OH kinase, suggesting that AKT2 may be an important signal mediator that contributes to the control of cell proliferation. We previously reported amplification and overexpression of AKT2 in human cancers. To investigate the transforming activity of AKT2, we used a retrovirus-based construct to express AKT2 in NIH3T3 cells. Overexpression of AKT2 was found to transform NIH3T3 cells, as determined by growth in soft agar and tumor formation in nude mice. The oncogenic activity of AKT2 was diminished by truncation of a 70-amino acid proline-rich region at the carboxyl-terminus. To facilitate the characterization of AKT2, we generated monoclonal and polyclonal antibodies against this protein. AKT2 was localized to the cytoplasm by cell fractionation experiments, immunocytochemistry, and immunofluorescence. Protein levels were more abundant in mitotic cells than in interphase cells. Western blot analysis of synchronized pancreatic cancer cells demonstrated that the expression level of AKT2 protein in mitotic cells is three to fivefold higher than in their interphase counterparts. A time-course study of phytohemagglutinin-stimulated lymphocytes revealed that AKT2 mRNA and AKT2 protein levels are highest 48-72 h after addition of mitogen, when cells are actively dividing. These data suggest that AKT2 could play a significant role in cell cycle progression and that the oncogenic activity of overexpressed AKT2 may be mediated by aberrant regulation of cellular proliferation.

3T3 Cells↗
PubMed1997

Characterizing exposure-disease association in human populations using the Lorenz curve and Gini index.

To characterize exposure-disease association in human populations, epidemiologists have long relied upon such indices as "relative risk' and/or 'attributable risk'. However, the relative risk is not in a common unit which permits comparison across different exposures or different diseases and the attributable risk may not adequately catch and describe the variation of disease risks in populations. The present paper discusses the possibility of using the summary index of the Lorenz curve, the Gini index, as an alternative measure of exposure-disease association. It is found that this index can be interpreted in several ways (as the coefficient of deviation in disease risk or relative risk, the information content of the exposure, the impact fraction of an exposure-lowering programme, and the averaged impact fraction) and is a promising alternative as a fundamental measure in epidemiology. Further studies are warranted to investigate its statistical properties.

Disease Transmission, Infectious↗
PubMed1997

One-step HPLC purification procedure for porcine brain 90-kDa heat shock protein.

The 90-kDa heat shock protein (HSP90) was purified from porcine brain by a novel single-step purification procedure using diethylaminoethyl high-performance liquid chromatography (HPLC). About 4.8 mg of HSP90 was isolated from 25 g wet wt porcine brain tissue. The purified protein possessed a single moiety on one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver staining. Western blotting using monoclonal antibody prepared against human HSP90 confirmed its identity as HSP90. These results indicate that small-scale HPLC purification of HSP90 from porcine brain tissue can be readily accomplished, with high yield, using a convenient one-step purification method. The procedure described in this paper represents a significant improvement in current purification methods for the isolation of HSP90 from porcine brain.

Animals↗
PubMed1997

Complications of palatoplasty for snoring or sleep apnoea.

A questionnaire was sent to consultant Otolaryngologists (483) throughout the UK to identify any mortality associated with uvulopalatoplasty and other forms of palatoplasties for snoring and/or obstructive sleep apnoea. The response rate was 76.8 per cent (371). Six intra- and post-operative deaths were reported and four were known to have obstructive sleep apnoea. Life-threatening morbidity occurred in at least seven patients (three known apnoeic), two required immediate tracheostomy and two were managed in the intensive care unit. This suggests that the apnoeic patients undergoing palatoplasties experienced significant mortality and morbidity. Pre-operative sleep study should be performed in all snoring patients to identify the apnoeic subgroup. Continuous positive airway pressure, management of excessive obesity, elective tracheostomy and other strategies should be first considered before palatoplasties in these patients.

Humans↗
PubMed1997

Immobilization of enzymes on methacrylamide-based copolymers.

A series of reactive polymeric supports for the covalent binding of enzymes was prepared from methacrylamide in conjunction with various copolymerized monomers. In all cases the specific surface area of the prepared copolymer particles increased with the ratio of crosslinker to monomer. The polymers containing oxirane and aldehyde groups were promising for direct binding of beta-galactosidase, whereas the supports containing amino groups also qualified for enzyme immobilization with glutaraldehyde.

Acrylamides↗
PubMed1997

Local and regional anesthesia for functional endoscopic sinus surgery.

An effective topical and regional anesthetic technique using 25% cocaine paste combined with intravenous midazolam hydrochloride was used in 554 patients undergoing functional endoscopic sinus surgery. The operative fields were excellent and all procedures were completed with little patient disturbance. Patients recovered rapidly from sedation and were usually fit for discharge on the same day. There were no anesthetic complications. The major surgical complication rate was 0.5%.

Anesthesia, Conduction↗
PubMed1997

Quantifying the future impact of disease on society: life table-based measures of potential life lost.

OBJECTIVES: Quantifying health status in human populations by means of an index such as "years of potential life lost" has recently received attention. However, such an index, being cross-sectional in nature, only measures the current burden to society resulting from a specific cause of death. METHODS: The author proposes new indices of potential life lost to quantify future impacts on society of particular causes of death. These indices also properly reflect the effects of competing risks. The computation is simple, requiring no more than a standard life-table calculation. Real-world as well as hypothetical data are used to illustrate the method. RESULTS: The new indices convey valuable health status information about a population that is not revealed by traditional indices. CONCLUSIONS: The new indices are promising alternatives as measures of future potential life lost.

Adolescent↗
PubMed1997

Assessment of dialysis adequacy using the dialysate urea monitor: preliminary experience of the dialysate urea monitor.

Numerous studies have identified a strong linkage between the delivered dialysis dose (Kt/V) and the survival of hemodialysis (HD) patients. However, the current method used to calculate Kt/V requires multiple blood samples and the process is complex and time consuming. We evaluate the performance of a recently developed on-line monitor (Biostat 1000 dialysate urea monitor, Baxter) that measures the urea concentration in the effluent dialysate and displays Kt/V and nPCR immediately after hemodialysis. To verify the performance of the urea monitor, we selected 21 hemodialysis patients, calculated their Kt/V and nPCR values from blood samples obtained during each hemodialysis, and compared the results with data obtained using the urea monitor. The Kt/V and nPCR values calculated by the urea monitor were both significantly correlated with those obtained using blood samples (R = 0.804, p < 0.001 in Kt/V and R = 0.749, p < 0.001 in nPCR). Our results suggest that the urea monitor may be used for on-line assessment of dialysis adequacy and obviates the need for blood sampling.

Blood Urea Nitrogen↗
PubMed1997

Hepatic portal venous gas associated with acute mesenteric infarction--a case report.

Hepatic portal venous gas (HPVG) is considered as an ominous prognostic sign and indicates the need for urgent surgical intervention. It has been associated with a wide variety of abdominal catastrophes, but the commonest and most serious one is infarcted bowel. This disease entity is difficult to be detected by conventional radiography. Ultrasonography and computed tomography have been reported to be more valuable methods in detecting HPVG and its cause. We report a case of HPVG associated with acute mesenteric infarction, which was detected early by ultrasonography. The computed tomography done later not only showed typical features of HPVG, but also disclosed intramural gas in the small intestine and gas in the superior mesenteric veins, which were diagnostic clues for acute mesenteric infarction. The patient survived after urgent surgery.

Aged↗
PubMed1996

Loss of heterozygosity analysis defines a critical region in chromosome 1p22 commonly deleted in human malignant mesothelioma.

Previous cytogenetic analysis has revealed frequent losses of chromosome 1p21-22 in human malignant mesothelioma, suggesting that the loss or inactivation of a tumor suppressor gene's) residing at this site may contribute to the tumorigenic conversion of mesothelial cells. To more precisely define the location of the target gene, primary tumor specimens and cell lines from 50 malignant mesotheliomas were examined for loss of heterozygosity using short tandem repeat polymorphism (STRP) markers. Nineteen STRP markers established by the Cooperative Human Linkage Center were selected for the initial screening of the entire short arm of chromosome 1. Thirty-seven cases (74%) showed allelic losses at least at one locus in 1p. Thirty-six of these cases showed losses of 1p21-22, including 23 with partial deletions involving this region. To obtain a higher resolution map of this region, another 13 STRP markers from the Genethon map were used to define the shortest region of overlapping deletions to a 4-cM segment flanked by the loci D1S435 and D1S236. The chromosomal location of the critically deleted region was confirmed to be within 1p22 by karyotypic and fluorescence in situ hybridization analyses.

Chromosomes, Human, Pair 1↗