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Lee KW, Lee CH, Oh DK, Kang JK, Eui Lee C, Kim J. Low-frequency collective chain dynamics in a model biomembrane. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:042903. [PMID: 11690071 DOI: 10.1103/physreve.64.042903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2001] [Revised: 07/06/2001] [Indexed: 05/23/2023]
Abstract
Proton NMR was employed as a probe for the collective hydrocarbon chain dynamics in decylammonium chloride (C10H21NH3Cl), a model biomembrane undergoing an irreversible structural phase transition sequence. Our rotating frame spin-lattice relaxation measurements revealed a low-frequency critical collective chain dynamics in the kHz regime, which is associated with the interdigitated to noninterdigitated chain configurational phase transition.
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Burkett DA, Lee WJ, Lee KW, Kim HC, Lee HI, Lee JS, Shin EH, Wirtz RA, Cho HW, Claborn DM, Coleman RE, Klein TA. Light, carbon dioxide, and octenol-baited mosquito trap and host-seeking activity evaluations for mosquitoes in a malarious area of the Republic of Korea. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2001; 17:196-205. [PMID: 14529088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Two field trials for commercially available and experimental mosquito traps variously baited with light, carbon dioxide, octenol, or combinations of these were evaluated in a malarious area at Paekyeon-Ri near Tongil-Chon (village) and Camp Greaves, Paju County, Kyonggi Province, Republic of Korea. The host-seeking activity for common mosquito species was determined using hourly aspirator collections from a human- and propane lantern-baited Shannon trap. The total number of mosquitoes and number of each species captured during the test were compared using 8 x 8 and 5 x 5 Latin square designs based on trap location. Significant differences were observed for the total number of mosquitoes collected in the 8 x 8 test, such that counterflow geometry (CFG) with CO2 > or = CFG with CO2 and octenol > or = Shannon trap > or = Mosquito Magnet with octenol > American Biophysics Corporation (ABC) light trap with light, CO2 (500 ml/min), and octenol > or = ABC light trap with light and dry ice > or = ABC light trap with light and CO2 > ABC light trap with light only. A concurrent 5 x 5 test found significant differences in trap catch, where Mosquito Magnet with octenol > New Jersey light trap > or = EPAR Mosquito Killer with CO2 > or = ABC light trap with light and dry ice > Centers for Disease Control (CDC) light trap (manufactured by John W. Hock) with light and octenol. Significant differences in trap catch were noted for several species including: Aedes vexans, Anopheles sinensis, An. yatsushiroensis, An. lesteri, Culex pipiens, and Cx. orientalis. Traps baited with octenol captured significantly fewer Cx. pipiens than those not baited with octenol. Likewise, no Cx. orientalis were captured in octenol-baited traps. Host-seeking activity showed a similar bimodal pattern for all species captured. Results from these field trap evaluations can significantly enhance surveillance efforts. Significantly greater numbers of mosquitoes were captured with mosquito traps using counterflow technology (e.g., Mosquito Magnet and CFG traps) when compared to standard light and carbon dioxide-baited traps. Additionally, field evaluations demonstrate that various traps can be utilized for isolation and detection of arboviruses and other pathogens.
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Chang HK, Kim JU, Cheon KS, Chung HR, Lee KW, Lee IH. HLA-B51 and its allelic types in association with Behçet's disease and recurrent aphthous stomatitis in Korea. Clin Exp Rheumatol 2001; 19:S31-5. [PMID: 11760395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE This case-control study was undertaken to evaluate the association of HLA-B51 antigen and its allelic types with Behçet's disease (BD) and with recurrent aphthous stomatitis (RAS), to investigate the degree of this association with diagnostic types and clinical variables of BD. METHODS The DNA typing of HLA-B51 by nested PCR-SSP was performed in 61 patients with BD, 56 patients with RAS, and in 70 healthy controls. Also, blind quality control study was done to assess the accuracy of nested PCR-SSP in HLA-B51-positive and negative BD patients on the microlymphocytotoxicity. In addition, direct DNA sequencing analysis was carried out in HLA-B51-positive individuals. RESULTS The outcome of nested PCR-SSP showed 100% concordance with those of the microlymphocytotoxicity. The prevalence of HLA-B51 in patients with BD was 55.7%, 16.1% in patients with RAS, and 15.7% in healthy controls. According to the diagnostic types of BD, all ten patients with complete BD had HLA-B51 antigen, and 47.1% in patients with incomplete BD (p = 0.002). In addition, the prevalence of HLA-B51 was statistically significant in patients with BD who had uveitis (p = 0.003) or erythema nodosum (p = 0.042). Direct DNA sequencing analysis revealed that the major allelic types in BD, RAS, and in healthy control were mostly HLA-B*51011. CONCLUSIONS Compared to patients with RAS or healthy controls, prevalence of HLA-B51 in the Korean patients with BD was much higher. The BD patients with B51 seemed to be susceptible for manifesting uveitis, erythema nodosum, and the full-blown syndrome as complete BD. Therefore the presence of HLA-B51 antigen in BD patients would be a genetic marker for the severe disease. In addition, there was no difference on the major allelic types of HLA-B51 in BD, RAS, and in healthy control.
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Chen CY, Huang CC, Zimmerman RA, Yuh YS, Chen SJ, Chin SC, Lee CC, Lee KW. High-resolution cranial ultrasound in the shaken-baby syndrome. Neuroradiology 2001; 43:653-61. [PMID: 11548174 DOI: 10.1007/s002340100569] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
With limited near-field resolution and accessible acoustic windows, sonography has not been advocated for assessing central nervous system injuries in the shaken-baby syndrome. Our purpose was to correlate high-resolution ultrasonographic characteristics of central nervous system injuries in whiplash injuries and the shaken-baby-syndrome with MRI and CT. Ultrasonographic images of 13 infants, aged 2-12 months, with whiplash or shaking cranial trauma were reviewed and compared with MRI in 10 and CT in 10. Five patients had serial ultrasonography and MRI or CT follow-up from 1 to 4 months after the initial injury. With ultrasonography we identified 20 subdural haematomas. MRI and CT in 15 of these showed that four were hyperechoic in the acute stage, three were mildly echogenic in the subacute stage, and that one subacute and seven chronic lesions were echo-free. Five patients had acute focal or diffuse echogenic cortical oedema which evolved into subacute subcortical hyperechoic haemorrhage in four, and well-defined chronic sonolucent cystic or noncystic encephalomalacia was seen at follow-up in two. Using ultrasonography we were unable to detect two posterior cranial fossa subdural haematomas or subarachnoid haemorrhage in the basal cisterns in three cases, but did show blood in the interhemispheric cistern and convexity sulci in two. U1-trasonography has limitations in demonstrating abnormalities remote from the high cerebral convexities but may be a useful adjunct to CT and MRI in monitoring the progression of central nervous system injuries in infants receiving intensive care.
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Pan SM, Chen MK, Chung MH, Lee KW, Chen IC. Expression and characterization of monocot rice cytosolic CuZnSOD protein in dicot Arabidopsis. Transgenic Res 2001; 10:343-51. [PMID: 11592713 DOI: 10.1023/a:1016692200454] [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: 11/12/2022]
Abstract
Cytosolic CuZnSOD removes deleterious superoxides from plant cells. In order to understand its function better, we sought to express a monocot CuZnSOD gene in transgenic Arabidopsis. We constructed a transgene using the CaMV 35S promoter to express a rice cytosolic CuZnSOD gene in Arabidopsis and generated over 200 transformants. A 16 kD polypeptide, the same size as the native rice CuZnSOD polypeptide, was detected in the transgenic Arabidopsis. Interestingly, two forms of rice CuZnSOD, rSODI and rSODII, having the same dimeric size, were detected in the transgenic plants. rSODII protein was relatively abundant but had low specific activity. In contrast, rSODI protein was relatively rare and had high specific activity. Inter-conversion of rSODI and rSODII could be achieved by the addition and removal of copper ions into the purified recombinant SOD and to the leaf extract of transgenic plants. Our analysis indicates that rSODI most likely corresponds to native rice CuZnSOD that has incorporated the Cu and Zn ions required for full activity, whereas the less active rSODII form may not have properly incorporated the necessary copper ions.
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Lee KW, Hwang KH, Kim CS, Han K, Chung YB, Park JS, Lee YM, Moon DC. Determination of recombinant human epidermal growth factor (rhEGF) in a pharmaceutical formulation by high performance liquid chromatography with electrochemical detection. Arch Pharm Res 2001; 24:355-9. [PMID: 11534771 DOI: 10.1007/bf02975106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel HPLC method with electrochemical detection has been developed for the determination of recombinant human epidermal growth factor (rhEGF) in pharmaceutical products. rhEGF was separated from other components in formulation on a reversed-phase C18 column with 24% acetonitrile in 0.1 M phosphate buffer (pH 4.75). The optimum electrochemical oxidation of EGF was obtained at 0.85 V vs. Ag/AgCl in a glassy carbon working electrode due to electroactive tyrosine, tryptophan, methionine, and arginine residues. The quantitation range was from 1.0 to 200 ng of rhEGF with the linear correlation coefficient greater than 0.999. The method was successfully applied for the quantitation of rhEGF in a pharmaceutical preparation.
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Cheng R, Lin B, Lee KW, Ortwerth BJ. Similarity of the yellow chromophores isolated from human cataracts with those from ascorbic acid-modified calf lens proteins: evidence for ascorbic acid glycation during cataract formation. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1537:14-26. [PMID: 11476959 DOI: 10.1016/s0925-4439(01)00051-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chromatographic evidence supporting the similarity of the yellow chromophores isolated from aged human and brunescent cataract lenses and calf lens proteins ascorbylated in vitro is presented. The water-insoluble fraction from early stage brunescent cataract lenses was solubilized by sonication (WISS) and digested with a battery of proteolytic enzymes under argon to prevent oxidation. Also, calf lens proteins were incubated with ascorbic acid for 4 weeks in air and submitted to the same digestion. The percent hydrolysis of the proteins to amino acids was approximately 90% in every case. The content of yellow chromophores was 90, 130 and 250 A(330) units/g protein for normal human WISS, cataract WISS and ascorbate-modified bovine lens proteins respectively. Aliquots equivalent to 2.0 g of digested protein were subjected to size-exclusion chromatography on a Bio-Gel P-2 column. Six peaks were obtained for both preparations and pooled. Side by side thin-layer chromatography (TLC) of each peak showed very similar R(f) values for the long wavelength-absorbing fluorophores. Glycation with [U-(14)C]ascorbic acid, followed by digestion and Bio-Gel P-2 chromatography, showed that the incorporated radioactivity co-eluted with the A(330)-absorbing peaks, and that most of the fluorescent bands were labeled after TLC. Peaks 2 and 3 from the P-2 were further fractionated by preparative Prodigy C-18 reversed-phase high-performance liquid chromatography. Two major A(330)-absorbing peaks were seen in peak 2 isolated from human cataract lenses and 5 peaks in fraction 3, all of which eluted at the same retention times as those from ascorbic acid glycated calf lens proteins. HPLC fractionation of P-2 peaks 4, 5 and 6 showed many A(330)-absorbing peaks from the cataract WISS, only some of which were identical to the asorbylated proteins. The major fluorophores, however, were present in both preparations. These data provide new evidence to support the hypothesis that the yellow chromophores in brunescent lenses represent advanced glycation endproducts (AGEs) probably due to ascorbic acid glycation in vivo.
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Lee YJ, Kim HT, Lee KW. Development of monitoring technology for airborne particulate matter. ENVIRONMENTAL MONITORING AND ASSESSMENT 2001; 70:3-20. [PMID: 11516018 DOI: 10.1023/a:1010679128979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Particulate matter suspended in the air has adverse effects on human health. Its level of concentration is an important parameter in evaluating the degree of hazard it poses to the atmosphere. Conventional methods used in measuring particulate matter are often filter-based, which indicates some disadvantages because such a base requires labor and time. In this study, to achieve real-time measurements, a new electrical method was developed for measuring PM10 and PM2.5 concentrations. The basic principle is to electrically charge particles passing through the PM inlet using a corona charger and measure the currents created by charged particles to obtain the number concentration of particulate matter. A new type inlet based on the particle cup impactor configuration was designed and its performance was evaluated. A unipolar diffusion charger was developed and the charger's efficiency was determined experimentally in terms of Pn, which represents the penetration through the charger, P, times the average charge number acquired by a particle, n, for different particle sizes. The correlation was constructed between the PM 10 (or the PM2.5) mass concentrations and the electrical currents due to particles, which were charged by the diffusion charger.
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Lee WY, Oh ES, Min CK, Kim DW, Lee JW, Kang MI, Min WS, Cha BY, Lee KW, Son HY, Kang SK, Kim CC. Changes in autoimmune thyroid disease following allogeneic bone marrow transplantation. Bone Marrow Transplant 2001; 28:63-6. [PMID: 11498746 DOI: 10.1038/sj.bmt.1703102] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2000] [Accepted: 04/24/2001] [Indexed: 11/08/2022]
Abstract
Autoimmune diseases can be transmitted and eliminated by bone marrow transplantation (BMT). There have been several cases of autoimmune thyroid disease (AITD) occurring after BMT, but AITD remission has been rarely reported. We present four cases in which the remission or transfer of AITD occurred after an allogeneic BMT. Two patients with severe aplastic anemia (SAA) showed evidence of remission of Hashimoto's thyroiditis which they had before allogeneic BMT. One patient with SAA, which developed during treatment with propylthiouracil for Graves' disease, underwent allogeneic BMT and showed evidence of Graves' disease remission following BMT. In one patient, new AITD occurred after an allogeneic BMT from an HLA-matched sibling who already had AITD. These cases support the evidence that the immune system is newly reconstituted after BMT, and severe autoimmune disease can be an indication for BMT. To fully understand the real changes in autoimmune status after BMT, long-term prospective studies are necessary.
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Chang SA, Cha BY, Yoo SJ, Ahn YB, Song KH, Han JH, Lee JM, Son HS, Yoon KH, Kang MI, Lee KW, Son HY, Kang SK. The effect of cilostazol on glucose tolerance and insulin resistance in a rat model of non-insulin dependent diabetes mellitus. Korean J Intern Med 2001; 16:87-92. [PMID: 11590907 PMCID: PMC4531709 DOI: 10.3904/kjim.2001.16.2.87] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND It has been reported that many peripheral vasodilating drugs might improve insulin resistance. Cilostazol, a antithrombotic agent, increases peripheral blood flow in non-insulin dependent diabetic patients. The effect of cilostazol treatment on insulin resistance in streptozotocin (STZ)-induced non-insulin dependent diabetic Wistar rats was examined. METHODS About a half of two-day old neonate siblings were injected intraperitoneally with STZ and maintained for six months, at which time they were compared with age-matched control rats for intraperitoneal glucose tolerance test (IPGTT) and for glucose infusion rate (GINF) in a euglycemic hyperinsulinemic glucose-clamp study. After that, these studies were also performed after feeding rat chow containing cilostazol (100 mg/kg/day) to rats with STZ-induced non-insulin dependent diabetes mellitus for four-weeks and compared with those of age-matched control rats. RESULTS In the intraperitoneal glucose tolerance test studies, plasma glucose levels of STZ-induced non-insulin dependent diabetic rats were significantly higher and plasma insulin levels significantly lower than those of age-matched control rats in the age of six months. Glucose infusion rate was lower in STZ-induced non-insulin dependent diabetic rats than those of age-matched control rats. However, after a four-week cilostazol treatment, glucose infusion rate of STZ-induced non-insulin dependent diabetic rats was not significantly different from that of control rats. CONCLUSION These findings suggested that cilostazol may improve insulin resistance in STZ-induced non-insulin dependent diabetic rats.
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Abstract
Systemic lupus erythematosus(SLE) is a prototypic autoimmune disease affecting various organ systems. Hypothermia is a rare manifestation of SLE. We experienced a case of SLE combined with hypothermia. A 36-year-old woman, who had been diagnosed as SLE 3 days before admission, admitted complaining of mental confusion. After admission, her body temperature, initially 36.1 degrees C, became 32.6 degrees C. Her core body temperature was less than 35.0 degrees C. Despite of warming with heating lamp and blankets, her core temperature did not reach 35.0 degrees C during 18 hours. Ten days later, her temperature exceeded 36.0 degrees C.
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Lee WY, Oh KW, Yoon KH, Kang MI, Cha BY, Lee KW, Son HY, Kang SK, Kim MS, Ahn KJ. Cushing's disease due to an ACTH-secreting pharyngeal pituitary tumor. Eur J Endocrinol 2001; 144:181-2. [PMID: 11182756 DOI: 10.1530/eje.0.1440181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lee KW, Ko BC, Jiang Z, Cao D, Chung SS. Overexpression of aldose reductase in liver cancers may contribute to drug resistance. Anticancer Drugs 2001; 12:129-32. [PMID: 11261885 DOI: 10.1097/00001813-200102000-00005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We previously found that about 29% of human liver cancers overexpressed aldose reductase (AR) and about 54% of them overexpressed an AR-like gene called ARL-1 that has similar enzymatic activities to AR. Since these aldo-keto reductases can reduce a broad spectrum of substrates including cytotoxic aldehydes, we were interested to find out if these enzymes can contribute to the resistance of liver cancer chemotherapy by inactivating some of the anticancer drugs. HepG2 cells, a stable line of liver cells, were induced to overexpress AR by hypertonicity. Cells that were cultured in hypertonic medium became more resistant to daunorubicin, suggesting that overexpression of AR made the cells more resistant to this drug. This is confirmed by the fact that addition of AR inhibitor sensitizes the cells to this drug again. This information may be important for designing new drugs to treat this deadly disease.
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Suh KS, Lee KW, Roh HR, Lee MK, Koh YT, Lee KU. Various types of donor hepatectomy according to the required graft volume in adult living donor liver transplantation. Transplant Proc 2001; 33:1410. [PMID: 11267350 DOI: 10.1016/s0041-1345(00)02531-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lee KW, Kligfield P, Dower GE, Okin PM. QT dispersion, T-wave projection, and heterogeneity of repolarization in patients with coronary artery disease. Am J Cardiol 2001; 87:148-51. [PMID: 11152829 DOI: 10.1016/s0002-9149(00)01306-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The clinically useful prognostic value of precordial QT dispersion in patients with heart disease is generally attributed to its measurement of regional heterogeneity of ventricular repolarization. However, when repolarization is abnormal, differences in measured QT intervals might result simply from variation in projection of the T-wave loop. To provide insight into the mechanism of QT dispersion, we used an analog device to transform conventional 12-lead electrocardiograms (ECGs) of 78 patients to derived 12-lead ECGs based on the heart vector. Because the electrical activity of the heart is represented by a single dipole, all QT dispersion in the transformed ECGs results from variation in projection of the T-wave loop and cannot be due to local heterogeneity of repolarization. Measured as the difference between the longest and shortest precordial QT intervals, QT dispersion in the derived ECGs, with no local heterogeneity of repolarization, was 53 +/- 49 ms (mean +/- SD). QT dispersion in these derived ECGs was similar in magnitude to that measured from the original standard 12-lead ECGs in these patients (49 +/- 23 ms, p = NS). Therefore, the precordial QT dispersion measured from standard ECGs of patients with coronary artery disease can be explained by interlead variation in precordial projection of the T-wave loop. Although regional heterogeneity might still contribute to precordial repolarization findings and to prognosis, this is not required to explain the QT dispersion observed in patients with coronary artery disease. Therefore, QT interval dispersion is not equivalent to heterogeneity of repolarization.
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Kim JM, Chung YH, Shin CM, Kim MJ, Lee KW, Cha CI. Spatial and temporal distribution of Bax in rat spinal cord during normal aging. Neurol Res 2001; 23:83-6. [PMID: 11210437 DOI: 10.1179/016164101101198172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Amytrophic lateral sclerosis is characterized by relentlessly progressive degeneration of spinal cord motor neurons. During the disease, the bcl-2 family genes have been reported to alter their expression levels. To understand the meaning of these changes, the expression pattern of Bax in rat spinal cord and its changing pattern during normal aging were investigated by immunohistochemical staining. Spatial expression of the protein showed a diffuse distribution pattern with immunoreactivity more prominent in the anterior hom. With advancement of age, the cell densities of Bax-positive cells tended to increase. The increasing expression of Bax might be positively associated with amyotrophic lateral sclerosis. This work demonstrates for the first time how Bax expression changes in rat spinal cord during normal aging.
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Park SH, Lee KW. Asymptotic Particle Size Distributions Attained during Coagulation Processes. J Colloid Interface Sci 2001; 233:117-123. [PMID: 11112314 DOI: 10.1006/jcis.2000.7222] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of the collision kernel on the self-preserving size distribution and on the gelation phenomenon of aerosol coagulation were investigated. An analytical solution for the asymptotic width of log-normally preserving size distribution during coagulation was obtained as a function of the degree of homogeneity using arbitrary shape of homogeneous collision kernels. From the solution obtained, it was shown that when the degree of homogeneity is larger than 1, self-preserving size distribution does not exist, and gelation occurs. A very accurate numerical coagulation simulation method, the sectional method, was also used for calculating the self-preserving particle size distribution for some specific classes of coagulation kernels and the results were compared with the analytical solution obtained by the log-normal method. Copyright 2001 Academic Press.
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Chen CY, Chang YC, Huang CC, Lui CC, Lee KW, Huang SC. Acute flaccid paralysis in infants and young children with enterovirus 71 infection: MR imaging findings and clinical correlates. AJNR Am J Neuroradiol 2001; 22:200-5. [PMID: 11158910 PMCID: PMC7975539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND AND PURPOSE Enterovirus 71 (EV71) infection is now considered an important cause of childhood acute flaccid paralysis. The purpose of our study was to determine whether EV71-infection-related acute flaccid paralysis in infants and young children has characteristic MR imaging patterns. METHODS Seven infants and young children with acute paralysis of the upper or lower extremities and positive EV71 cultures underwent spinal MR studies during an outbreak of hand-foot-and-mouth disease in Taiwan in 1998. RESULTS Acute paralysis was observed in one upper extremity in two patients, in one lower extremity in three patients, and in both lower extremities in two patients. None of the patients had sensory impairment or bulbar palsy. MR studies showed unilateral or bilateral hyperintense lesions in the anterior horn regions of the cord on T2-weighted images in six patients. No abnormal signal was present in one patient. Two of three patients who received intravenous injections of contrast material had ventral root enhancement on T1-weighted images. One of them also had enhancement of the unilateral anterior horn cells. At clinical follow-up, both patients with bilateral anterior horn abnormalities had residual motor weakness, whereas only one of the five patients with unilateral involvement had residual weakness. CONCLUSION EV71 radiculomyelitis tends to be unilateral and to specifically involve both the anterior horn cells of the cord and the ventral roots. MR imaging allows early detection of spinal cord and root lesions.
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Lee KW, Briggs JM. Comparative molecular field analysis (coMFA) study of epothilones-tubulin depolymerization inhibitors: pharmacophore development using 3D QSAR methods. J Comput Aided Mol Des 2001; 15:41-55. [PMID: 11217918 DOI: 10.1023/a:1011140723828] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A three-dimensional quantitative structure-activity relationship (3D QSAR) study has been carried out on epothilones based on comparative molecular field analyses (CoMFA) using a large data set of epothilone analogs, which are potent inhibitors of tubulin depolymerization. Microtubules, which are polymers of the a/beta-tubulin heterodimer, need to dissociate in order to form the mitotic spindle, a structure required for cell division. A rational pharmacophore searching method using 3D QSAR procedures was carried out and the results for the epothilones are described herein. One-hundred and sixty-six epothilone analogs and their depolymerization inhibition properties with tubulin were used as a training set. Over a thousand molecular field energies were generated and applied to generate the descriptors of QSAR equations. Using a genetic function algorithm (GFA) method, combined with a least square approach, multiple QSAR models were considered during the search for pharmacophore elements. Each GFA run resulted in 100 QSAR models, which were ranked according to their lack of fit (LOF) scores, with a total of 40 GFA runs having been performed. The 40 best QSAR equations from each run had adequate fitted correlation coefficients (R from 0.813 to 0.863) and were of sufficient statistical significance (F value from 7.2 to 10.9). The pharmacophore elements for epothilones were studied by investigating the hit frequency of descriptors (i.e. the sampling probabilities of grid points from the GFA studies) from the set of the 4,000 top scoring QSAR equations. By comparing the frequency with which each grid point appeared in the QSAR equations, three candidate regions in the epothilones were proposed to be pharmacophore elements. Two of them are completely compatible with the recent model proposed by Ojima et al. [Proc. Natl. Acad. Sci. USA, 96 (1999) 4256], however, one is quite different and is necessary to accurately predict the activities of all 166 epothilone molecules used in our training set. Finally, by visualizing the 35 most probable grid points, it was found that changes related to the C6, C7, C8, C 12, S20, and C21 atoms of the epothilones were highly correlated to their activity.
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Ko KF, Lee KW. Cerebrotendinous xanthomatosis in three siblings from a Chinese family. Singapore Med J 2001; 42:30-2. [PMID: 11361235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Cerebrotendinous xanthomatosis (CTX) is exceptionally rare in the Chinese population. We reported a 31-year-old Chinese male in Hong Kong, who has the characteristic features of cerebrotendinous xanthomatosis including the multiple xanthomas of tendons, mental retardation, bilateral cataracts, cerebellar ataxia and spasticity of the left arm, high concentrations of plasma phytosterols and abnormal MR of brain. On screening the family, two other siblings of 27 and 29 respectively, have tendon xanthomas and high plasma phytosterols. An extensive search of the international medical literature, including the Medline, has revealed only one other case report of cerebrotendinous xanthomatosis in Taiwan. CTX is a potentially treatable disease. It is hoped by alertness, early diagnosis and treatment can be made, and hence prevent further progression of the disease.
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Shin CM, Chung YH, Kim MJ, Shin DH, Kim YS, Gurney ME, Lee KW, Cha CI. Immunohistochemical study on the distribution of Bcl-2 and Bax in the central nervous system of the transgenic mice expressing a human Cu/Zn SOD mutation. Brain Res 2000; 887:309-15. [PMID: 11134620 DOI: 10.1016/s0006-8993(00)03014-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the present study, we performed immunohistochemical studies to investigate the changes of Bcl-2 and Bax in the central nervous system of the transgenic mice expressing a human Cu/Zn SOD mutation. In contrast to the controls, a high density of Bcl-2-IR astrocytes were detected all around the gray matter of the spinal cord of the mutant transgenic mice. Bcl-2-IR astrocytes were also detected in the cerebellum and brainstem of transgenic mice. Specific immunoreactivity for Bax was seen in the spinal cord and brainstem of transgenic mice. Immunostaining for Bax was identified only in neurons and not in glial cells. Our present study demonstrated the distribution of Bcl-2 and Bax in detail using immunohistochemical methods through the central nervous system of the transgenic mice, for the first time.
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Abstract
HLA-A24 is the second most frequently expressed HLA-A type in Koreans (GF 22.8%). Four different serologic reaction patterns were observed in Korean A24 positive samples using a commercial serologic typing kit. To clarify the nature of serologic heterogeneity, thirteen A24 positive DNA samples representing the four different serologic reaction patterns were subjected to DNA sequencing analysis of the amplified HLA-A genes from each sample. Four A*24 alleles (A*2402101, A*2403, A*2408, and A*2421) were associated with the four unique serologic reaction patterns. During this study, a novel allele, A*2421, was characterized. The new sequence is similar to A*2402101, differing at codon 127 (AAA-->AAC; K-->N). By comparing putative amino acid sequences and serologic reaction patterns of A*24 allelic products identified in this study, several crucial sites for A24- and A9-specific antibody binding were predicted: 127K for A24 antibody binding, and 62E-65G and 166D-167G for A9 antibody binding. This information will be helpful for accurately assigning HLA-A24 types by serology and for predicting serologic types of new alleles.
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Oh MJ, Choi JH, Kim IH, Lee YH, Huh JY, Park YK, Lee KW, Chough SY, Joo KS, Ku BS, Saw HS. Detection of epidermal growth factor receptor in the serum of patients with cervical carcinoma. Clin Cancer Res 2000; 6:4760-3. [PMID: 11156231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Epidermal growth factor receptor (EGFR) is overexpressed in a variety of malignancies, including breast, lung, gastric, and cervical carcinoma. Its overexpression has been associated with disease progression or poor prognosis in patients with cervical carcinoma. In the present study, the levels of EGFR were determined in serum from 38 patients with cervical carcinoma [invasive or recurrent carcinoma (n = 26) and carcinoma in situ (CIS; n = 12)] and 38 healthy female controls using ELISA. The mean serum level for EGFR in patients with invasive or recurrent carcinoma (165 +/- 60 fmol/ml) was significantly elevated (P < 0.0001) compared with that of healthy controls (66 +/- 17 fmol/ml) and also higher (P = 0.015) than that of patients with CIS (126 +/- 25 fmol/ml). In addition, there was a significant difference in the mean serum levels of EGFR between patients with CIS and healthy controls (P < 0.0001). Thirty-five patients (92%) with cervical carcinoma [invasive or recurrent (n = 24) and CIS (n = 11)] had elevated serum, EGFR levels above the cutoff value of 100 fmol/ml (defined as 2 SD above the mean of the controls). In conclusion, the serum EGFR level was elevated in a significant proportion of patients with cervical carcinoma, and it demonstrated an increasing tendency according to disease progression from normal tissue through CIS to invasive cervical carcinoma. Therefore, it may have a potential usefulness as a biological marker of cervical carcinoma.
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Choi YH, Ahn YB, Yoon KH, Kang MI, Cha BY, Lee KW, Son HY, Kang SK. New ADA criteria in the Korean population: fasting blood glucose is not enough for diagnosis of mild diabetes especially in the elderly. Korean J Intern Med 2000; 15:211-7. [PMID: 11242809 PMCID: PMC4531770 DOI: 10.3904/kjim.2000.15.3.211] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND To compare the 1997 American Diabetes Association (ADA) criteria with the 1985 World Health Organization (WHO) criteria in categorization of the diabetes diagnostic status of Koreans and to define clinical characteristics of subjects diagnosed differently by the two criteria. METHODS In 810 Korean subjects, we analyzed blood glucose and insulin response during 75 g oral glucose tolerance test (OGTT). According to current WHO criteria, the cutoff values of FPG which distinguish normal and IGT from diabetes were determined. Then the subjects were categorized according to both WHO and ADA criteria. The clinical characteristics of the subjects with different diagnostic categories by the two criteria were defined. RESULTS The FPG cut point distinguishing diabetes from IGT was 117 mg/dl, and from normal was 110 mg/dl. The overall agreement between the ADA criteria and the WHO criteria was moderate, as reflected in the kappa of 0.45. 141 of subjects categorized diabetes by WHO criteria were not diagnosed with ADA criteria. These discordant subjects were older in age and showed blunted early insulin response than concordant normal subjects. CONCLUSION These results suggest that mild diabetes by the WHO criteria, especially in the elderly, would not be diagnosed as diabetes by the ADA FPG criteria only. Thus, in a group at high risk for developing diabetes or in a relatively older age group, we should continue using the OGTT.
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