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Abstract
Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in the neonatal period. NEC causes ulceration of the intestinal mucosa and may lead to perforation or a stricture. To the best of the authors' knowledge intestinal inflammatory polyps after NEC have not been described previously. The authors report on a 17-week-old boy with pseudopolyps at the site of a colonic stricture after NEC.
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Gallagher RP, Rivers JK, Lee TK, Bajdik CD, McLean DI, Coldman AJ. Broad-spectrum sunscreen use and the development of new nevi in white children: A randomized controlled trial. JAMA 2000; 283:2955-60. [PMID: 10865273 DOI: 10.1001/jama.283.22.2955] [Citation(s) in RCA: 218] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
CONTEXT High nevus density is a risk factor for cutaneous malignant melanoma. Melanocytic nevi originate in childhood and are largely caused by solar exposure. OBJECTIVE To determine whether use of broad-spectrum, high-sun protection factor (SPF) sunscreen attenuates development of nevi in white children. DESIGN Randomized trial conducted June 1993 to May 1996. SETTING AND PARTICIPANTS A total of 458 Vancouver, British Columbia, schoolchildren in grades 1 and 4 were randomized in 1993. After exclusion of nonwhite children and those lost to follow-up or with missing data, 309 children remained for analysis. Each child's nevi were enumerated at the start and end of the study in 1996. INTERVENTION Parents of children randomly assigned to the treatment group (n=222) received a supply of SPF 30 broad-spectrum sunscreen with directions to apply it to exposed sites when the child was expected to be in the sun for 30 minutes or more. Children randomly assigned to the control group (n=236) received no sunscreen and were given no advice about sunscreen use. MAIN OUTCOME MEASURE Number of new nevi acquired during the 3 years of the study, compared between treatment and control groups. RESULTS Children in the sunscreen group developed fewer nevi than did children in the control group (median counts, 24 vs 28; P=.048). A significant interaction was detected between freckling and study group, indicating that sunscreen use was much more important for children with freckles than for children without. Modeling of the data suggests that freckled children assigned to a broad-spectrum sunscreen intervention would develop 30% to 40% fewer new nevi than freckled children assigned to the control group. CONCLUSIONS Our data indicate that broad-spectrum sunscreens may attenuate the number of nevi in white children, especially if they have freckles. JAMA. 2000.
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Amrith S, Saw SM, Lim TC, Lee TK. Ophthalmic involvement in cranio-facial trauma. J Craniomaxillofac Surg 2000; 28:140-7. [PMID: 10964549 DOI: 10.1054/jcms.2000.0138] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES This is a retrospective descriptive case study which will look into the spectrum of ophthalmic involvement in cases with orbital and eye injuries after cranio-facial trauma and to analyse the visual and motility outcome. MATERIAL One hundred and four cases with ophthalmic involvement after cranio-facial trauma that were referred to and seen in the eye department of a tertiary teaching hospital in Singapore between 1991-97 were included in the study. METHODS The case records of 104 such patients were traced. The demographic data, the mode of injury, the type of fracture sustained and presence of serious eye injury were noted. The details about visual acuity, significant diplopia and enophthalmos at the first and last visits were charted. Presence of traumatic optic neuropathy including the type of treatment given was recorded. RESULTS There was a male preponderance (82%). The industrial accidents were 21%, only next to road traffic accidents, which constituted approximately 36.5%. The predominant types of fractures seen were blow-out orbital fractures, complex fractures comprising of Le-Fort II, III, panfacial and fronto-basilar skull fractures. Diplopia was the most common presenting feature (40%) with visual acuity disturbance (23% having <6/60) as the next most common finding. Traumatic optic neuropathy was seen in 20% of patients and serious eye injury was present in 9% of patients. The incidence of traumatic optic neuropathy was significantly higher (p<0.001) in patients with complex fractures and fronto-basilar fractures, as compared to the blow-out and zygomatico-maxillary fractures. Analysis of final results indicated 15% as having significant diplopia in one or more gazes and 12.5% as having a vision of <6/60. CONCLUSION Diplopia and visual acuity disturbances seem to be the most common ophthalmic presentations in cranio-facial trauma. A significant number of patients suffer from poor vision and significant diplopia despite treatment.
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Chen YY, Yao YD, Wang CR, Li WH, Chang CL, Lee TK, Hong TM, Ho JC, Pan SF. Size-induced transition from magnetic ordering to kondo behavior in (Ce,Al) compounds. PHYSICAL REVIEW LETTERS 2000; 84:4990-4993. [PMID: 10990849 DOI: 10.1103/physrevlett.84.4990] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/1999] [Indexed: 05/23/2023]
Abstract
Magnetic ordering and Kondo behavior coexist in three (Ce,Al)-based compounds: CeAl2, Ce3Al, and Ce3Al11. A common feature apparently independent of crystal structures also prevails in terms of the size-induced transition between these two magnetic phenomena. As the particle size is reduced to nanoscale, the specific heat anomaly associated with the magnetic ordering diminishes. Although the Kondo temperature also decreases, the entropy associated with Kondo anomaly exhibits a large increase. This results in an enhancement of the Kondo behavior and an increased coefficient gamma of the linear term in specific heat. For example, in 80 A CeAl2 the extrapolated r(0) reaches 9000 mJ mol Ce-1 K-2.
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Abstract
Studies of the factors affecting the first recurrence of ischemic stroke have reported inconsistent findings. Types of initial stroke and the racial differences in study samples are among the explanations that may account for this inconsistency. The aims of this study were to estimate the cumulative recurrence rates of noncardioembolic ischemic stroke and identify the factors that influence the first recurrence of noncardioembolic ischemic stroke in the Taiwanese Chinese population. Four hundred and sixty-six patients with noncardioembolic ischemic stroke from thirteen hospitals in Taiwan were followed up in this study to ascertain first recurrence of noncardioembolic ischemic stroke between October 1992 and April 1995. The Kaplan-Meier method was used to estimate the cumulative recurrence rate. The Cox regression model was used to ascertain the significant factors affecting the first recurrence of noncardioembolic ischemic stroke. The overall cumulative recurrence rate was 10.5% (49/466) from the follow-up period of 30 months. After adjustment for age, sex, treatment modes, and variables pertinent to blood pressure, the site of brain lesion remained a significant factor. The relative risk of first recurrence for the basal ganglion vs. the region of middle cerebral artery was 3.06 (95% CI: 1.29-7.26). The brain lesion site was demonstrated to be an independent predictor of risk for the first recurrence of noncardioembolic ischemic stroke among the Taiwanese Chinese population. Whether this finding was also seen in other populations should be corroborated in future research.
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Lodder AL, Lee TK, Ballester R. Characterization of the Wsc1 protein, a putative receptor in the stress response of Saccharomyces cerevisiae. Genetics 1999; 152:1487-99. [PMID: 10430578 PMCID: PMC1460702 DOI: 10.1093/genetics/152.4.1487] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Wsc1p, Wsc2p, Wsc3p, and Wsc4p, members of a novel protein family in the yeast Saccharomyces cerevisiae, are putative sensors or receptors in the stress response. Genetic characterization suggests that the WSC family are upstream regulators of the stress-activated PKC1-MAP kinase cascade and are required for the heat shock response and for maintenance of cell wall integrity. The Wsc proteins share sequence characteristics: at their N terminus they have a cysteine motif and a serine/threonine-rich domain predicted to be extracellular, a hydrophobic domain suggested to be transmembranous, and a variable, highly charged C terminus that may be involved in intracellular signaling. Although a role for the WSC genes in maintenance of cell wall integrity has been firmly established, little is known about the properties of the proteins. As reported here, to study its properties in vivo, we epitope tagged the Wsc1 protein. Wsc1p was found to fractionate with the membrane pellet after high-speed centrifugation. Extraction experiments show that Wsc1p is an integral membrane protein present in two forms: one solubilized by detergent, the other Triton X-100 insoluble. Our results also show that Wsc1p is glycosylated and phosphorylated. To characterize the contribution of different domains to the function of Wsc1p, we generated various deletion constructs. Analysis of the properties and function of the mutant proteins shows that the predicted extracellular serine/threonine-rich domain is required for Wsc1p functionality, as well as its glycosylation. A mutant Wsc1 protein lacking the putative transmembrane domain is not functional and partitions to the soluble fraction. Overexpression of full-length Wsc1p inhibits cell growth, with the N terminus alone being sufficient for this inhibition. This suggests that Wsc1p may function in a complex with at least one other protein important for normal cell growth.
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Chen CN, Chou CI, Hwang CR, Kang J, Lee TK, Li SP. Monte Carlo dynamics in global optimization. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 60:2388-93. [PMID: 11970036 DOI: 10.1103/physreve.60.2388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/1999] [Indexed: 04/18/2023]
Abstract
Several very different optimization problems are studied by using the fixed-temperature Monte Carlo dynamics and found to share many common features. The most surprising result is that the cost function of these optimization problems itself is a very good stochastic variable to describe the complicated Monte Carlo processes. A multidimensional problem can therefore be mapped into a one-dimensional diffusion problem. This problem is either solved by direct numerical simulation or by using the Fokker-Planck equations. Above certain temperatures, the first passage time distribution functions of the original Monte Carlo processes are reproduced. At low temperatures, the first passage time has a path dependence and the single-stochastic-variable description is no longer valid. This analysis also provides a simple method to characterize the energy landscapes.
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Lee TK, O'Brien K, Eaves GS, Christie KI, Varga L. Effect of blood storage on radiation-induced micronuclei in human lymphocytes. Mutat Res 1999; 444:201-6. [PMID: 10477355 DOI: 10.1016/s1383-5718(99)00078-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To evaluate the effect of blood storage on the yield of micronuclei (MN) in both irradiated (in vivo and ex vivo) and unirradiated peripheral blood lymphocytes (PBL), we applied the MN assay in cytokinesis-blocked (CB) PBL obtained from healthy subjects (n=11), and from cancer patients (n=10) who were undergoing fractionated partial-body radiotherapy (xRT). The heparinized blood samples were exposed to 137Cs-irradiation (0 Gy or 2 Gy) immediately after blood collection and were stored upright in test tubes either at room temperature (22 degrees C) or in the refrigerator (5 degrees C). Duplicate whole blood cultures from each sample were set up at 0 h, 96 h, and 120 h after ex vivo irradiation. Giemsa (10%) stained slides were prepared from each culture. MN yield was determined per 1000 binucleated cells. As compared to that obtained from the corresponding fresh blood samples, we found that (1) the 22 degrees C blood storage temperature did not affect MN yields in PBL of either healthy subjects or cancer patients up to 96 h, either with or without ex vivo irradiation; and (2) while blood samples were stored at 5 degrees C, the MN yield increased significantly in PBL of healthy subjects (with or without ex vivo irradiation) at 120 h, and in cancer patients (with ex vivo irradiation) at 96 h and 120 h. Since handling of the blood sample is important for CBMN assay during shipment or in the laboratory, our findings showed that blood storage at 22 degrees C or at 5 degrees C up to 96 h appeared to provide insignificant variations of the MN results as compared to fresh blood samples. However, the 96 h of blood storage at 5 degrees C elevated the MN frequency in ex vivo irradiated PBL of cancer patients who were undergoing xRT.
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Sung RYT, Leung SSF, Lee TK, Cheng JCY, Lam PKW, Xu YY. Cardiopulmonary response to exercise of 8- and 13-year-old Chinese children in Hong Kong: results of a pilot study. Hong Kong Med J 1999; 5:121-127. [PMID: 11821579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVES: To assess the cardiopulmonary response of healthy Hong Kong Chinese children to the treadmill test, and to identify anthropometric factors that may be related to fitness. DESIGN: Cross-sectional study. SETTING: University teaching hospital, Hong Kong. PARTICIPANTS: Forty-three 8-year-old and fifty-seven 13-year-old healthy Chinese children from middle or lower socio-economic class families in Shatin and nearby areas. MAIN OUTCOME MEASURES: The forced vital capacity, 1-second forced expiratory volume, pulse rate, and blood pressure were measured before and after undertaking the treadmill test (Bruce protocol). The endurance time until volitional exhaustion, the number of metabolic equivalents of energy used, and the sum of the skinfold thicknesses were also obtained. RESULTS: Multiple regression analysis showed that the sum of the skinfold thicknesses was positively associated with pulse rate and diastolic blood pressure at all stages of exercise, and was negatively associated with the endurance time of and number of metabolic equivalents of energy used by the 8-year-old children. The 13-year-old children had a longer cardiopulmonary endurance than the 8-year-old children. In both age-groups, pulmonary function was positively associated with height and weight. CONCLUSION: The study provides useful reference data for Hong Kong Chinese 8- and 13-year-old children when subjected to the treadmill test. A larger study is needed to establish the normal standards for children of all different ages.
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Jung MY, Bock JY, Baik SO, Lee JH, Lee TK. Effects of roasting on pyrazine contents and oxidative stability of red pepper seed oil prior to its extraction. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 1999; 47:1700-1704. [PMID: 10564041 DOI: 10.1021/jf981028l] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Red pepper seeds were roasted with constant stirring for 6, 9, 10, and 12 min at 210 degrees C, and oils were extracted from the roasted red pepper seeds using an expeller. The iodine values and fatty acid compositions of red pepper seed oils did not change with roasting time. The fatty acid composition of the oil obtained from the red pepper seeds roasted for 6 min was 0.24% myristic acid, 13. 42% palmitic acid, 0.33% palmitoleic acid, 2.07% stearic acid, 10. 18% oleic acid, 73.89% linoleic acid, and 0.37% linolenic acid, showing a fatty acid composition similar to that of high-linoleate safflower oil. Thirteen alkylpyrazines were identified in the roasted red pepper seed oils: 2-methylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, 2-ethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-5-methylpyrazine, trimethylpyrazine, 2,6-diethylpyrazine, 2-ethyl-3,5-dimethylpyrazine, tetramethylpyrazine, 2, 3-diethyl-5-methylpyrazine, 2-isobutyl-3-methylpyrazine, and 3, 5-diethyl 2-methylpyrazine. The pyrazine content increased markedly as the roasting time increased, showing 2.63, 5.01, 8.48, and 13.10 mg of total pyrazine/100 g of oils from the red pepper seeds roasted for 6, 8, 10, and 12 min, respectively, at 210 degrees C. 2, 5-Dimethylpyrazine in the roasted red pepper seed oil seemed to be the component most responsible for the pleasant nutty aroma of the oils. The oxidative stabilities of oils increased greatly as the roasting time increased.
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Padilla RR, Lee TK. Pressure-laminated athletic mouth guards: a step-by-step process. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION 1999; 27:200-9. [PMID: 10634126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Of the variety of mouth guards available to the conscientious athlete for protection of oral structures, the pressure-laminated appliance provides the best fit and most protection. The pressure-lamination technique, however, is not widely known among dentists. This article contains a step-by-step description of making pressure-laminated athletic mouth guards.
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Park JI, Shim JK, Do JW, Kim SY, Seo EK, Kwon HJ, Lee TK, Kim JK, Choi DY, Kim CH. Immune-stimulating properties of polysaccharides from Phellodendri cortex (Hwangbek). Glycoconj J 1999; 16:247-52. [PMID: 10596900 DOI: 10.1023/a:1007084506071] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Heteropolysaccarides were isolated from the Korean medicinal plant, Phellodendri cortex (Hwangbek), by hot water and alkali extractions. The extracted polysaccharides were fractionated into eight fractions and they are mainly composed of D-N-acetylglucosamine, D-galactose, D-mannose, and D-glucose. Among the polysaccharide fractions, Fr.-2 showed a potent B-lymphocyte-stimulating activity in a system using polyclonal antibody forming cells in C57BL/6XC3H mice at dosages of 2-10 mg. On the basis of their solubility in aqueous ethanol, four fractions of Fr.-2-1 to Fr.-2-4 were further obtained from the Fr.-2, and Fr.-2-3 was divided into Fr.-2-3-1, 2, 3, and 4 by DEAE cellulose chromatography. The main activity was found in Fr.-2-3-2, which contained 100% (w/w) of carbohydrates and further purified to Fr.-2-3-2-2 by gel filtration chromatography using TSK Gel HW50S. Fr.-2-3-2-2, having a molecular weight of about 230 kDa, showed the highest B-cell-stimulating activity and the half-maximal concentration for B-lymphocyte-stimulating activity was ca. 2.2 microg/ml.
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Leung KY, Lee TK, Lee CN, Sum TK, Chan MYM, Tong CM. The effects of different dosages of oestrogen on the bone mineral density of postmenopausal Hong Kong Chinese women: randomised controlled trial. Hong Kong Med J 1999; 5:9-14. [PMID: 11821561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE: To determine the effects of different dosages of conjugated equine oestrogen on the bone mineral density of postmenopausal Hong Kong Chinese women. DESIGN: A 1-year three-arm randomised controlled trial. SETTING: Out-patient setting at a governmental hospital in Hong Kong. PARTICIPANTS: One hundred and five women aged 45 years or older, in whom menopause had occurred not more than 2 years previously. INTERVENTION: Women were assigned randomly to treatment with conjugated equine oestrogen 0.625 mg/d or 0.3 mg/d, or no oestrogen. MAIN OUTCOME MEASURE: Bone mineral density. RESULTS: Women who were assigned to the control group showed a significant reduction in bone mineral density in both the femoral neck and the lumbar spine (3.6%; P=0.001 and 4.0%; P<0.001, respectively). Those who received oestrogen 0.3 mg/d showed a significant reduction (3.9%; P=0.010) and a non-significant reduction (2.2%; P=0.141) in their lumbar spine and femoral neck bone mineral densities, respectively. In contrast, there was little change in the spinal and femoral neck bone mineral densities in women who received estrogen 0.625 mg/d. CONCLUSION: The minimum effective dosage of conjugated equine oestrogen to prevent osteoporosis in postmenopausal Hong Kong Chinese women is 0.625 mg/d. The bone mineral density, however, was maintained but not increased.
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Lee TK, Kim CH. Molecular Cloning and Expression of an Endo-β-1,4-D-glucanase I (Avicelase I) Gene from Bacillus cellulyticus K-12 and Characterization of the Recombinant Enzyme. Appl Biochem Biotechnol 1999; 80:121-40. [PMID: 15304785 DOI: 10.1385/abab:80:2:121] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/1998] [Accepted: 11/04/1998] [Indexed: 11/11/2022]
Abstract
Bacillus cellulyticus K-12 Avicelase (Avicelase I; EC 3.2.1.4) gene (ace A) has been cloned in Escherichia coli by using the vector pT7T3U19 and HindIII- HindIII libraries of the chromosomal inserts. The libraries were screened for the expression of avicelase by monitoring the immunoreaction of the antiavicelase (immunoscreening). Positive clones (Ac-3, Ac-5, and Ac-7) contained the identical 3.5-kb HindIII fragment as determined by restriction mapping and Southern hybridization, and expressed avicelase efficiently and constitutively using its own promoter in the heterologous host. From the immunoblotting analysis, a polypeptide that showed a carboxymethylcellulase (CMCase) activity with an Mr of 64,000 was detected. The recombinant endo 1,4-beta-D-glucanase I was purified to homogeneity from an intracellular fraction of E. coli by DEAE-Toyopearl M650, Phenyl Toyoperal M650, and TSK gel HW50S chromatography. The enzyme had a monomeric structure, its relative molecular mass being 65 kDa by gel filtration and 64 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pI was 5.3 and the optimal pH was 4.6, and the enzyme was stable at pH 4.0-10.5. The enzyme had a temperature optimum of 50 degrees C and was stable at 55 degrees C for 48 h, and retained approx 20% of its activity after 30 min at 70 degrees C. It showed high activity toward carboxymethylcellulose (CMC) as well as p-nitrophenyl-beta-D-cellobioside, 4-methylumbelliferyl cellobioside, Avicel, filter paper, and some cellooligosaccharides. Km values for CMC and Avicel were 7.6 and 85.2 mg/mL, respectively, whereas Vmax values were 201 and 9.2 micromol x min(-1) x mg(-1), respectively. Cellotetraose (G4) was preferentially cleaved into cellobiose (G2) and cellopentaose (G5) was cleaved into G2 + cellotriose (G3), whereas cellohexaose (G6) was cleaved into G4 + G2 and, to a lesser extent, into G3 + G3. G3 was not cleaved at all. G2 was the main product of Avicel hydrolysis. G2 inhibited whereas Mg++ stimulated the activity of CMCase and Avicelase. Hydrolysis of CMC took place with a rapid decrease in viscosity but a slow liberation of reducing sugars. Based on these results, it appeared that the cellulase should be regarded as endo type, although it hydrolyzed Avicel.
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Abstract
In order to study the health status and prevalence of diseases in elderly Chinese people in Taiwan, a hospital-based, physician-conducted epidemiological survey was undertaken. Study subjects were people aged > or = 65 years who were randomly selected from four regions of Taiwan. A total of 2600 subjects were studied. Most of the study subjects visited the hospitals for detailed history taking, physical examination and laboratory tests, including urinalysis, blood chemistry, electrocardiography, and chest and lumbar spine radiography. The cardiovascular data of 2518 subjects (males 1283) comprised this report. The prevalence of hypertension in the aged Chinese in Taiwan was high in both males and females (males 33.2%, females 40.9%, combined 37%). Coronary artery disease was also common (11.4%), but the prevalence was relatively low compared with Western people. Other cardiovascular diseases such as aortic aneurysm and valvular heart disease were rare. About 70% of the electrocardiograms were found abnormal. This well-organized, large-scale epidemiological survey not only presents useful information for local medical care for the elderly but also provides important data for comparison between different people in the world.
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Lee TK, Chow ST, Ng TL. A 10-year review of drug seizures in Singapore. MEDICINE, SCIENCE, AND THE LAW 1998; 38:311-316. [PMID: 9808942 DOI: 10.1177/002580249803800406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The trend of illicit drug seizures and analysis in Singapore over a 10-year period from 1986 to 1995 was examined and reviewed. The main drugs were heroin, opium, cannabis, and illicit tablets containing benzodiazepines and amphetamines. The emergence of amphetamines in early 1996 was a major departure from the traditional drug abuse pattern in Singapore. Changes in the legal definitions of opium and cannabis were also reviewed.
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Lee TK, O'Brien K, Christie K, Wiley AL, Karlsson UL. Effect of ex vivo hyperthermia on radiation-induced micronuclei in lymphocytes of cancer patients before and during radiotherapy. Mutat Res 1998; 417:1-8. [PMID: 9729237 DOI: 10.1016/s1383-5718(98)00086-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
To investigate the effect of ex vivo hyperthermia (HT) and 137Cs-irradiation on micronucleus (MN) production in cytokinesis-blocked lymphocytes, we obtained the peripheral blood samples from the same cancer patients (n=6) before and during fractionated partial-body radiotherapy (xRT). The whole blood cultures were heated at 43.5 degrees C for 60 min, followed by 137Cs irradiation (0-4 Gy). The control cultures from the same patients were incubated at 37 degreesC after being exposed to radiation. The lymphocytes were then stimulated with PHA. Cytochalasin B was applied at 44 h, and lymphocytes were harvested at 72 h. MN frequency was determined on Giemsa-stained slides. We found that in patients before xRT, HT (43.5 degrees C) significantly increased the MN yield (mean+/-SEM) in unirradiated lymphocytes from 15.6+/-2.8 (37 degrees C) to 39.7+/-10.9. Further, in patients either before or during xRT, when the lymphocytes were treated with HT (43.5 degrees C) and combined with ex vivo irradiation, the MN yield (Y) could be estimated by a linear equation Y=C+alphaD. Our findings indicate that as measured by the MN production in cytokinesis-blocked lymphocytes, HT alone at 43.5 degrees C++ induced DNA damage. Moreover, it enhanced the radiation-induced cytogenetic damage. Therefore, the application of HT may impair the T-cell function in cancer patients who are receiving radiotherapy. 1998 Elsevier Science B.V.
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Li L, Lee TK, Meier PJ, Ballatori N. Identification of glutathione as a driving force and leukotriene C4 as a substrate for oatp1, the hepatic sinusoidal organic solute transporter. J Biol Chem 1998; 273:16184-91. [PMID: 9632674 DOI: 10.1074/jbc.273.26.16184] [Citation(s) in RCA: 178] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
oatp1 is an hepatic sinusoidal organic anion transporter that mediates uptake of various structurally unrelated organic compounds from blood. The driving force for uptake on oatp1 has not been identified, although a role for bicarbonate has recently been proposed. The present study examined whether oatp1-mediated uptake is energized by efflux (countertransport) of intracellular reduced glutathione (GSH), and whether hydrophobic glutathione S-conjugates such as leukotriene C4 (LTC4) and S-dinitrophenyl glutathione (DNP-SG) form a novel class of substrates for oatp1. Xenopus laevis oocytes injected with the complementary RNA for oapt1 demonstrated higher uptake of 10 nM [3H]LTC4 and 50 microM [3H]DNP-SG, and higher efflux of [3H]GSH (2.5 mM endogenous intracellular GSH concentration). The oatp1-stimulated LTC4 and DNP-SG uptake was independent of the Na+ gradient, cis-inhibited by known substrates of this transport protein and by 1 mM GSH, and was saturable, with apparent Km values of 0.27 +/- 0.06 and 408 +/- 95 microM, respectively. Uptake of [3H]taurocholate, an endogenous substrate of oatp1, was competitively inhibited by DNP-SG. Of significance, oatp1-mediated taurocholate and LTC4 uptake was cis-inhibited and trans-stimulated by GSH, and [3H]GSH efflux was enhanced in the presence of extracellular taurocholate or sulfobromophthalein, indicating that GSH efflux down its large electrochemical gradient provides the driving force for uptake via oatp1. The stoichiometry of GSH/taurocholate exchange was 1:1. These findings identify a new class of substrates for oatp1 and provide evidence for GSH-dependent oatp1-mediated substrate transport.
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Jeng JS, Lee TK, Chang YC, Huang ZS, Ng SK, Chen RC, Yip PK. Subtypes and case-fatality rates of stroke: a hospital-based stroke registry in Taiwan (SCAN-IV). J Neurol Sci 1998; 156:220-6. [PMID: 9588861 DOI: 10.1016/s0022-510x(98)00046-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Stroke data bank can afford important information regarding risk factors, pathogenesis, prognosis, etc. By means of hospital-based stroke registry, we investigated the risk factors and case-fatality rates in different types of stroke and transient ischemic attack (TIA) patients at the National Taiwan University Hospital in 1995. After excluding ineligible patients, 995 patients aged 1-98 years (575 men and 420 women) were recruited. Men predominated in all age groups for stroke and TIA in general except for cerebral hemorrhage (CH) in patients aged < 35 years and subarachnoid hemorrhage (SAH) in patients aged > or = 45 years. Of these, 676 (67.9%), 41 (4.1%), 228 (22.9%) and 50 (5%) patients were classified in the categories of cerebral infarction (CI), TIA, CH and SAH, respectively. The CI/CH ratio was 2.96. Hypertension remained one of the most important risk factors for CI, CH and TIA patients. Severe extracranial carotid artery stenosis (> or = 50%) was found in 12% of the CI patients and 27% of the TIA patients, but not found in the CH and SAH patients. Of these patients, the 30-day case-fatality rate was 10.9%, highest in SAH (30%), followed by CH (24.1%) and CI (5.6%). There were 41 in-hospital stroke patients who had significantly higher case-fatality rates than the other stroke patients (P<0.001 for all stroke, CI and CH patients by chi2 test). As compared to the previous stroke registries in Taiwan, there is a secular trend of increasing CI/CH ratios. These findings in Taiwan were compared with those in other populations, including other Asian, Caucasian and black populations. The CI/CH ratios in Asian populations, including Chinese, Japanese and Korean, were much lower than those in Caucasian and black populations. Dietary, environmental and genetic factors probably play important roles in these differences.
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95
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Lee TK, Westenkow DR. Comparison of blood pressure measured by oscillometry from the supraorbital artery and invasively from the radial artery. J Clin Monit Comput 1998; 14:113-7. [PMID: 9669448 DOI: 10.1023/a:1007481416222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In previous studies, oscillometric blood pressure measured from the supraorbital artery has been shown to agree quite well with pressure measured from the brachial artery in normal subjects. In this study, surgical patients whose conditions warranted the use of invasive blood pressure monitoring during the surgery were chosen. We compared systolic and diastolic blood pressure measured oscillometrically from the supraorbital artery with intraarterial blood pressures, measured invasively from the radial artery. A pressure bladder was attached to the forehead of each patient. The bladder was connected to a forehead blood pressure monitor. A catheter was inserted in a radial artery, and connected to a pressure monitor. Forehead blood pressure was measured every 5 min. Radial arterial pressure was averaged over the same period during which the forehead measurement was made. Blood pressures measured with the two methods were compared. For the systolic pressure, the difference between the two methods was -9.9 +/- 17.9 mm Hg (mean +/- SD). For diastolic pressure, the difference was -8.0 +/- 10.9 mm Hg. There was a significant difference between the two methods in the patient population chosen in this study.
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96
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Yip PK, Jeng JS, Lee TK, Chang YC, Huang ZS, Ng SK, Chen RC. Subtypes of ischemic stroke. A hospital-based stroke registry in Taiwan (SCAN-IV). Stroke 1997; 28:2507-12. [PMID: 9412641 DOI: 10.1161/01.str.28.12.2507] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE To better understand the clinical pattern and further elucidate the risk factors and outcome in different subtypes of cerebral infarction (CI) of the Chinese in Taiwan, we analyzed the National Taiwan University Hospital Stroke Registry in 1995 and performed an ethnic comparison with similar data banks. METHODS From the National Taiwan University Hospital Stroke Registry in 1995, 676 patients (383 men and 293 women; mean age, 64.9 years; SD, 13.8 years; range, 1 to 98 years) with CI were recruited for this analysis. CI was classified into five subtypes based on clinical manifestations, ultrasonographic studies, and neuroimaging findings: large-artery atherosclerosis, lacunae, cardioembolism, other less common determined causes, and undetermined cause. Vascular risk factors, extracranial carotid artery atherosclerosis, and 30-day case-fatality rates were investigated in each subtype of CI. RESULTS Of all CI patients, 17%, 29%, 20%, 6%, and 29% were classified as large-artery atherosclerosis, lacunae, cardioembolism, other determined causes, and undetermined cause subtypes, respectively. The present results were compared with those from eight similar Western stroke registries. The relative incidence of lacunar CI in Chinese patients was more common, but large-artery atherosclerotic CI was less common than in whites. Hypertension was frequently seen in CI patients, especially in those with lacunae (85%) and large-artery atherosclerosis (69%). Patients with cardioembolism had a higher percentage of atrial fibrillation (69%), left ventricular hypertrophy, and ischemic heart disease than the other patients. Patients with large-artery atherosclerosis had more vascular risk factors, such as hypertension, diabetes mellitus, smoking, and carotid stenosis. Cardioembolic patients had higher case-fatality rates than other CI patients. Of the cardioembolic patients, 17.3% and 21.8% died within 30 days and during hospitalization, respectively. CONCLUSIONS The proportion of CI subtypes varied in different stroke registries. This may be partly due to applied classification criteria and racial-ethnic differences. Awareness of the risk factors and outcome in each subtype of stroke may afford further insights into the surveillance and treatment of cerebrovascular disease.
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97
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Paleyanda RK, Velander WH, Lee TK, Scandella DH, Gwazdauskas FC, Knight JW, Hoyer LW, Drohan WN, Lubon H. Transgenic pigs produce functional human factor VIII in milk. Nat Biotechnol 1997; 15:971-5. [PMID: 9335047 DOI: 10.1038/nbt1097-971] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Deficiency or abnormality of coagulation factor VIII (FVIII) causes a bleeding disorder called hemophilia A. Treatment involves FVIII concentrates prepared from pooled human plasma or recombinant FVIII (rFVIII) prepared from mammalian cell culture. The cost of highly purified FVIII or rFVIII is a major factor in hemophilia therapy and restricts prophylaxis. We have sought to generate a new source of rFVIII by targeting expression of the human FVIII cDNA to the mammary gland of transgenic pigs using the regulatory sequences of the mouse whey acidic protein gene. The identity of processed heterodimeric rFVIII was confirmed using specific antibodies, by thrombin digestion and activity assays. The secretion of as much as 2.7 micrograms/ml of rFVIII in milk was over tenfold higher than in normal plasma. Up to 0.62 U/ml of rFVIII was detected in an assay in which rFVIII restored normal clotting activity to FVIII-deficient human plasma.
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98
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Pan WH, Chen JY, Haung SL, Liou TL, Lee TK, Wang LY, Chen CJ, Lin SL, Lo CH. Reference spirometric values in healthy Chinese neversmokers in two townships of Taiwan. CHINESE J PHYSIOL 1997; 40:165-74. [PMID: 9434893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The present community-based study was performed to provide predictive equations and lower boundaries of normal values for forced expiratory volume in one second (FEVI), forced vital capacity (FVC), and their percent ratio (FEV1%) in non-smoking, healthy adult men and women residing in communities, using ATS-recommended techniques and equipment. Use was made of data collected cross-sectionally from Nov. 1990 to Dec. 1993 in an ongoing longitudinal study on evolution of cardiovascular disease risk factors in Chinese. The spirometric values in our population reached their peak at around age 20. After age 20, a downward age trend was observed for FVC, FEV1, and FEV1%. Linear and negative relations were found in adults for each of the three spirometric values with age. Linear and positive relations were found between height and FVC or FEV1, but not between height and FEV1%. The age trends of FVC and FEV1 in Chinese adults were similar to those in Caucasians. Mean FVC and FEV1 levels of Chinese in Taiwan were systematically lower than those of Caucasians for a given height and a given age. Age and height specific percentile values of FVC and FEV1 and the age-specific percentile value of FEV1% are provided for adult men and women in this community study.
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99
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Wang TL, Chiang FT, Hsu KL, Tseng CD, Lee TK, Tseng YZ. Abnormal circadian blood pressure changes in patients with acute cerebrovascular disorders. J Formos Med Assoc 1997; 96:710-7. [PMID: 9308325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The central neural mechanisms of circadian rhythm are well known in animal models but less so in humans. In this study we looked for correlations between abnormalities of circadian rhythm and the sites of stroke, with the aim of identifying the location regulating the circadian rhythm in humans. We investigated the circadian profiles of arterial pressure in 100 stroke patients by ambulatory blood pressure monitoring within 2 days after their first stroke. Patients also underwent brain computed tomography and measurements of plasma norepinephrine and adrenal hormones. A total of 52 patients (group A) had abnormal patterns of circadian blood pressure rhythm while 48 patients had normal patterns (group N). The risk of an abnormal 24-hour blood pressure pattern was strongly inversely correlated with the distance between the lesion and the hypothalamus. There was also a close positive correlation between the distance from the lesion to the hypothalamus and the circadian indices of arterial blood pressure (systolic and diastolic pressure) in both groups. Abnormal circadian changes in adrenal hormones were found in 30 of 52 patients in group A, and in nine of 48 patients in group N. Apparently, the circadian rhythm of blood pressure is modulated mainly by direct neural effects and partly by the hormonal effects of the hypothalamus and its associated neural pathways. Individualized antihypertensive treatment and additional monitoring for possible cardiac events should be performed for those at a high risk of autonomic dysfunction.
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100
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Huang ZS, Chiang TL, Lee TK. Stroke prevalence in Taiwan. Findings from the 1994 National Health Interview Survey. Stroke 1997; 28:1579-84. [PMID: 9259752 DOI: 10.1161/01.str.28.8.1579] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE Stroke has been the second leading cause of death for all ages in Taiwan since 1983. However, despite the severity of the threat, stroke prevalence in Taiwan has not yet been addressed in a nationwide survey. In this study, the stroke prevalence in Taiwan was investigated using data from the 1994 National Health Interview Survey. METHODS This nationwide survey sought to obtain a nationally representative sample of households in Taiwan by using three-stage stratified random sampling with a probability proportional to size. In the first stage, 58 townships were selected, from the 359 townships in Taiwan, according to their administrative structure and level of socioeconomic development. In the second stage, 149 basic administrative regions (tsun or li) were selected from the selected 58 townships. Finally, 3814 households were selected from the 149 selected tsuns or lis. Field interviews were carried out between October 1994 and December 1994. Follow-up interviews with families of stroke patients were made 2 years later. RESULTS Of the selected households 3119, or 81.8%, responded. A total of 11925 persons were interviewed, and 71 of them were stroke patients, with a crude point prevalence rate of 5.95 per 1000. The stroke prevalence increased steadily with age, from 0.51 per 1000 in persons aged 35 to 44 years to 113.6 per 1000 in persons aged 85 years or over. There was a weak association with higher stroke prevalence for persons living in eastern Taiwan or those of lower educational level. The overall male/female prevalence ratio was 1.17. The results of follow-up interviews showed a cumulative mortality rate of 25.4% within the 2-year period and an ischemic/hemorrhagic stroke ratio of 1.33 in 35 patients whose stroke type could be validated. CONCLUSIONS Age was the most important factor correlating to stroke prevalence. On the basis of this result, planning policies and programs for stroke prevention in Taiwan should give a higher priority to (1) aggressive primary prevention for aged people who are apparently at higher risk of stroke and (2) early reduction of stroke risk factors in younger aged people whose immediate risk of stroke is lower but would increase significantly with age.
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