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Gwon JS, Ju WK, Park SJ, Kim IB, Lee MY, Oh SJ, Chun MH. The regulatory expression of neuronal nitric oxide synthase in the ischemic rat retina. Neuroreport 2001; 12:3385-9. [PMID: 11711891 DOI: 10.1097/00001756-200110290-00047] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated the expression and cellular localization of neuronal nitric oxide synthase (nNOS) in the rat retina, following ischemic injury induced by transient increase of intraocular pressure. In the normal retina, nNOS immunoreactivity was localized to certain populations of amacrine cells, displaced amacrine cells and a few bipolar cells. Following transient ischemia, retinal neurons expressing the immunoreactivity increased and peaked three days after reperfusion. Quantitative evaluation using immunoblotting confirmed that nNOS expression showed a peak value (500% of control levels) at 3 days, and then decreased again to 150% of controls by 4 weeks after reperfusion. Our findings suggest that this over-produced NO may act as a neurotoxic agent in the ischemic rat retina.
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152
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Seo KK, Kim SC, Jun IO, Oh MM, Lee MY. Synergistic effects of sildenafil on relaxation of rabbit and rat cavernosal smooth muscles when combined with various vasoactive agents. BJU Int 2001; 88:596-601. [PMID: 11678758 DOI: 10.1046/j.1464-4096.2001.02388.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate which vasoactive agents have synergistic effects on the cavernosal smooth muscles of rabbits and rats when the agents are combined with sildenafil. MATERIALS AND METHODS Relaxation responses of cavernosal smooth muscle to single agents (phentolamine, moxisylyte, sodium nitroprusside, forskolin, vasoactive intestinal peptide, VIP, papaverine and sildenafil) in the rabbit, and prostaglandin-E1 and sildenafil in the rat, and to combinations of each agent plus sildenafil, were assessed in vitro. The response to sildenafil of the rabbit strips with and without incubation with l-arginine (1 mmol/L) for 20 min was also evaluated. The effective concentrations for a half-maximal response of single agents and combination solutions were compared. RESULTS All single agents induced concentration-dependent relaxation of the rabbit and rat cavernosal smooth muscles. There was significant synergism on rabbit cavernosal smooth muscle when the sildenafil was combined with forskolin, sodium nitroprusside, VIP or phentolamine. There was also significant synergism with sildenafil plus prostaglandin-E1 in rat cavernosal muscles. There were no synergistic effects of combinations of sildenafil plus moxisylyte, papaverine or l-arginine. CONCLUSIONS These results suggest potentially effective combined therapies of sildenafil and intraurethral or intracavernosal prostaglandin-E1, intracavernosal forskolin or VIP, or oral phentolamine for patients with erectile dysfunction who have no success after monotherapy with these agents.
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153
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Min DS, Choi JS, Chun MH, Chung JW, Lee MY. Transient expression of phospholipase D1 in developing rat hippocampus. Neurosci Lett 2001; 310:125-8. [PMID: 11585583 DOI: 10.1016/s0304-3940(01)02091-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We investigated the distribution of phospholipase D1 (PLD1) protein in the developing rat hippocampus using an affinity-purified peptide antibody against PLD1. Immunoreactivity for PLD1 was first seen in some scattered cells in the hippocampus at embryonic day 18. At postnatal day 1 (P1), many PLD1 immunoreactive cells were observed in the CA1 and CA3 sectors, subiculum and the hilus of the dentate gyrus. During the first postnatal week, there was an abrupt increase of immunoreactive neurons in the hippocampus, and their number and intensity peaked at P7. During the second postnatal week, there was an abrupt decrease in the number of immunoreactive hippocampal neurons. By P14, no significant labeling was found in the hippocampus. These results corresponded well with those from Western blot analysis, suggesting that PLD1 may regulate the developmental processes of hippocampal neurons.
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154
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Tsai YG, Lee MY, Yang KD, Chu DM, Yuh YS, Hung CH. A single dose of nebulized budesonide decreases exhaled nitric oxide in children with acute asthma. J Pediatr 2001; 139:433-7. [PMID: 11562625 DOI: 10.1067/mpd.2001.116295] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study was conducted to investigate whether a single dose of nebulized budesonide effectively decreased airway inflammation as demonstrated by exhaled nitric oxide (eNO) levels. A single dose of nebulized budesonide, but not nebulized terbutaline, rapidly decreased eNO levels in 6 hours. The decrease in eNO levels induced by nebulized budesonide was correlated to an increase in peak expiratory flow rate.
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155
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Lee YJ, Jin SW, Jang SH, Jang YS, Lee EK, Kim YJ, Lee MY, Park JC, Rho TH, Kim JH, Hong SJ, Choi KB. A case of spontaneous pneumomediastinum and pneumopericardium in a young adult. Korean J Intern Med 2001; 16:205-9. [PMID: 11769580 PMCID: PMC4531731 DOI: 10.3904/kjim.2001.16.3.205] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [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
Spontaneous medialstinal emphysema (pneumomediastinum) and pneumopericardium may be defined as the presence of free air or gas in the mediastinal structures and in the pericardial sac without an apparent precipitating cause. It most frequently occurs in young healthy adults without serious underlying pulmonary disease. Although pneumomediastinum and pneumopericardium is often asymptomatic, it may cause pain in the neck and chest, dysphonia and shortness of breath. Treatment is supportive unless the patient has a history of trauma from foreign body aspiration. The course of spontaneous pneumomediastinum and pneumopericardium is usually benign and self-limited. A case of spontaneous pneumomediastinum, pneumopericardium and subcutaneous emphysema in a 20-year-old male is reported in this paper.
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156
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Hung CH, Hua YM, Lee MY, Tsai YG, Yang KD. Evaluation of different nebulized bronchodilators on clinical efficacy and hypokalemia in asthmatic children. ACTA PAEDIATRICA TAIWANICA = TAIWAN ER KE YI XUE HUI ZA ZHI 2001; 42:287-90. [PMID: 11729705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Acute asthma attack continues to be a major cause for children admitted to the emergency room. Nebulized beta 2-adrenergic agonists are still the first-line drugs for a rapid bronchodilation effect and an easily administered drug during acute asthma attack. The bronchodilator-induced hypokalemia is thought significant in adult group, but is often ignored in children group. In this study, we conducted a randomized study to compare the laboratory and clinical effects between nebulized salbutamol and terbutaline. We found that both salbutamol and terbutaline nebulization induced a significant hypokalemia (p < 0.05). Terbutaline nebulization also significantly improved the peak expiratory flow rate (PEFR) and respiratory rate (RR), but not venous partial pressure of oxygen (PvO2), venous carbon dioxide tension (PvCO2) and O2 saturation in venous blood (SvO2). In contrast, salbutamol improved not only PEFR and RR, but also PvO2, PvCO2, and SvO2 30 minutes of administration. In conclusion, the nebulized salbutamol, although induced a hypokalemic effect which is similar to terbutaline group, has a better effect on improving O2 saturation than nebulized terbutaline with the same dose 30 minutes after administered for children with acute asthma attack.
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157
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Lee JY, Bae ON, Chung SM, Lee MY, Chung JH. Menadione induces endothelial dysfunction mediated by oxidative stress and arylation. Chem Biol Interact 2001; 137:169-83. [PMID: 11551532 DOI: 10.1016/s0009-2797(01)00235-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Our previous studies showed that menadione causes endothelial dysfunction which results in decreased relaxation and increased contraction of blood vessels. This investigation examined the role of two possible mechanisms (oxidative stress and arylation) in menadione-induced endothelial dysfunction. Menadione increased superoxide anion generation in aortic rings in a dose-dependent manner. Superoxide dismutase (SOD), reversed the inhibitory effects of menadione on vascular relaxation. The relaxation induced by the NO donor, sodium nitroprusside, was inhibited by menadione pretreatment in a dose-dependent manner. Endothelial nitric oxide synthase activity (eNOS) was suppressed by menadione. Menadione resulted in a dose-dependent reduction of cGMP levels accumulated by acetylcholine. This reduction of cGMP levels was blocked by SOD treatment, suggesting that superoxide anion generated by menadione could play a role in the inhibition of the nitric oxide pathway. Evidence supporting a possible role for arylation in impaired vascular relaxation was suggested by the observation that benzoquinone, which does not induce oxidative stress in aortic rings, inhibited acetylcholine-induced vascular relaxation to the same extent as menadione. Collectively, these results suggest that menadione can cause endothelial dysfunction in blood vessels by the inhibition of the nitric oxide pathway via superoxide anion generation and that arylation activity may also be another important mechanism.
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158
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Chung SM, Lee JY, Lee MY, Bae ON, Chung JH. Adverse consequences of erythrocyte exposure to menadione: involvement of reactive oxygen species generation in plasma. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2001; 63:617-629. [PMID: 11549121 DOI: 10.1080/152873901316857798] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Previous studies demonstrated that menadione, a representative quinone compound, reacts nonenzymatically with thiols in plasma, resulting in the generation of reactive oxygen species and potentiation of menadione-induced platelet damage. Because of the reported association of menadione with hemolytic anemia in vivo, investigations were undertaken to identify the free radicals generated from the interaction of menadione with plasma, and to assess the potential role of plasma-generated free-radical species in menadione-dependent erythrocyte toxicity. In rat plasma, menadione increased the rate of oxygen consumption and both luminol- and lucigenin-amplified chemiluminescence in a concentration-dependent manner. Superoxide dismutase (SOD) inhibited lucigenin-amplified chemiluminescence, suggesting formation of superoxide anion. Menadione also induced significant increases in chemiluminescence when erythrocytes were suspended in plasma, but not when cells were suspended in buffer. Consistent with these findings, menadione-dependent hemolysis of erythrocytes occurred only when the cells were suspended in plasma. Various free-radical inhibitors were tested for their ability to inhibit menadione-induced hemolysis. Catalase and mannitol each produced significant inhibition, including an additive effect when both compounds were present, while SOD had no marked effect. In addition, pretreatment with 3-amino-1,2,4-triazole, an intracellular catalase inhibitor, potentiated menadione-induced cytotoxicity in the presence of plasma. These results suggest that both hydrogen peroxide and hydroxyl radicals are involved in menadione-mediated plasma erythrocyte cytotoxicity; however, superoxide anion does not appear to play a direct role.
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159
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Sze YK, Xue LZ, Lee MY. Treatment of alloy-electroplating wastewater by an automated solvent extraction technique. ENVIRONMENTAL TECHNOLOGY 2001; 22:979-990. [PMID: 11561955 DOI: 10.1080/09593332208618234] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Electroplating with highly toxic metals is being gradually replaced by alloy or mixed-metal electroplating. We developed a solvent extraction method for the treatment of waste rinsewater generated in Zn-Co alloy electroplating, based on the studies of the extraction properties. An alkyl ester of an alkylphosphonic acid (PC-88A) or a dialky phosphinic acid (Cyanex 272) was used as the extractant. The two metals were co-extracted into the organic solvent and then separately recovered in a simple process. The feasibility of the process was demonstrated with automated mixer-settler solvent extraction units.
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160
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Park KS, Kim YS, Cho YH, Lee MY, Chung MS. Effects of alkalinity of household dishwashing liquids on hand skin. Contact Dermatitis 2001; 45:95-8. [PMID: 11553119 DOI: 10.1034/j.1600-0536.2001.045002095.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The objective of this research was to investigate the effects of alkaline pH conditions of dishwashing liquids on hand skin of Korean panelists after repeated exposure. A group of 30 persons with normal hands immersed their hands, for a total of 15 min a day for 4 days, into household cleansing solutions adjusted to pH 7.4, 10.0 and 10.8, respectively. The effects of alkalinity of household cleansing solutions on hand skin were evaluated by measuring overall and dry hand-skin grades, as well as the degrees of hand-skin hydration estimated before and after the repeated immersion exposures to the 3 test products. No statistically-significant difference (p>0.05) was found among the parameters from the repeated immersion exposures to the test products. These findings indicate that increases of pH up to 10.8 of household cleansing solutions did not worsen either overall, dry hand-skin conditions or the level of hand-skin hydration.
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161
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Kim SR, Lee JY, Lee MY, Chung SM, Bae ON, Chung JH. Association of quinone-induced platelet anti-aggregation with cytotoxicity. Toxicol Sci 2001; 62:176-82. [PMID: 11399805 DOI: 10.1093/toxsci/62.1.176] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Various anti-platelet drugs, including quinones, are being investigated as potential treatments for cardiovascular disease because of their ability to prevent excessive platelet aggregation. In the present investigation 3 naphthoquinones (2,3-dimethoxy-1,4-naphthoquinone [DMNQ], menadione, and 1,4-naphthoquinone [4-NQ]) were compared for their abilities to inhibit platelet aggregation, deplete glutathione (GSH) and protein thiols, and cause cytotoxicity. Platelet-rich plasma, isolated from Sprague-Dawley rats, was used for all experiments. The relative potency of the 3 quinones to inhibit platelet aggregation, deplete intracellular GSH and protein thiols, and cause cytotoxicity was 1,4-NQ > menadione >> DMNQ. Experiments using 2 thiol-modifying agents, dithiothreitol (DTT) and 1-chloro-2,4-dintrobenzene (CDNB), confirmed the key roles for GSH in quinone-induced platelet anti-aggregation and for protein thiols in quinone-induced cytotoxicity. Furthermore, the anti-aggregative effects of a group of 12 additional quinone derivatives were positively correlated with their ability to cause platelet cytotoxicity. Quinones that had a weak anti-aggregative effect did not induce cytotoxicity (measured as LDH leakage), whereas quinones that had a potent anti-aggregative effect resulted in significant LDH leakage (84-96%). In one instance, however, p-chloranil demonstrated a potent anti-aggregative effect, but did not induce significant LDH leakage. This can be explained by the inability of p-chloranil to deplete protein thiols, even though intracellular GSH levels decreased rapidly. These results suggest that quinones that deplete GSH in platelets demonstrate a marked anti-aggregative effect. If this anti-aggregative effect is subsequently followed by depletion of protein thiols, cytotoxicity results.
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162
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Lee MY, Kim J. A rapid screen for putative mislocalization mutations by using a GAL4-hybrid protein. Mol Cells 2001; 11:275-80. [PMID: 11459215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
A GAL4 one-hybrid system was used to develop an indirect assay for intracellular localization. The Kar1 protein, a component of the yeast spindle pole body (SPB), was shown to be targeted to the SPB by electron microscopic analysis, or indirect immunofluorescence methods. To assay localization of the Kar1p by measuring the reporter gene expression on solid media, we constructed Kar1-Gal4 hybrid proteins with or without the SPB localization domain. The long fusion Kar1(299)-Gal4 with the localization domain led to non-growth on SC-His + AT media, and quite a low level of the lacZ reporter gene expression. The short fusion Kar1(107)-Gal4 without the localization domain caused a full activation of the reporter genes, HIS3 and lacZ, indicating that the protein remains in the nucleoplasm. These results suggest that the Kar1(299)-Gal4p fusion protein, localized to the SPB, can be clearly differentiated with the mislocalized protein by assaying the reporter gene expression. By utilizing the Kar1(299)-Gal4 construct, we isolated ten spontaneous mutations that were defective in the Kar1-Gal4p localization. Four of these mutations were in the same complementation group. We propose, therefore, that the Gal4-hybrid localization assay can be utilized in cases where the target organelle or the structure is too small for microscopic analysis, or in the initial screening for mutations defective in localization.
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163
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Lee EJ, Min DS, Kang WS, Lee MY, Oh SJ, Chun MH. The expression and cellular localization of phospholipase D1 in the rodent retina. Brain Res 2001; 905:240-4. [PMID: 11423101 DOI: 10.1016/s0006-8993(01)02516-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Phospholipase D (PLD) is one of the intracellular signal transduction enzymes and plays an important role in a variety of cellular functions. We investigated the expression and cellular localization of the PLD isozyme PLD1 in the rodent retina. Western blot analysis showed the presence of PLD1 at the protein level in the rat, mouse and guinea pig retinas. PLD1 immunoreactivity was localized in all Müller cells. Thus, PLD1 protein appears to be important in the functions of these cells in the rodent retina.
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164
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Xu H, Zhang P, Liu L, Lee MY. A novel PCNA-binding motif identified by the panning of a random peptide display library. Biochemistry 2001. [PMID: 11284708 DOI: 10.1021/bi010103] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proliferating cell nuclear antigen (PCNA) has recently been identified as a target for the binding of proteins involved in DNA replication, DNA repair, and cell cycle control. The interactions between PCNA and a number of these proteins are known to be mediated by a conserved peptide motif. In this study, a random peptide library in which peptide sequences are displayed on the E. coli bacterial flagellin protein was screened for PCNA-binding sequences. Analysis of the retrieved peptide sequences verified the presence of the known PCNA-binding motif. In addition, a second, larger group of peptides containing a different consensus sequence for PCNA binding was discovered. This sequence was found to be present on DNA polymerase delta, and a peptide conforming to this sequence was demonstrated to bind to PCNA. Database search and analysis show that many proteins contain the second consensus sequence. These include proteins that are involved in DNA replication, repair, and cell cycle control. The demonstration of this second PCNA-binding motif may provide a basis for identifying and experimentally testing specific proteins for the structural basis for PCNA binding.
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165
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Igarashi Y, Lee MY, Matsuzaki S. Heparin column analysis of serum type 5 tartrate-resistant acid phosphatase isoforms. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 757:269-76. [PMID: 11417871 DOI: 10.1016/s0378-4347(01)00157-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The objective of the present study was to develop a specific method for the separation of tartrate-resistant acid phosphatase (TRAP) derived exclusively from osteoclasts. Heparin column-bound TRAP in human serum was separated into three peaks of TRAP activity when eluted with a linear gradient of sodium chloride. The last peak corresponded to TRAP 5b which was first named according to its electrophoretic mobility [Clin. Chem. 24 (1978) 309] and was considered to be derived from osteoclasts [J. Bone Miner. Res. 13 (1998) 683]. The second peak was found to be TRAP 5a. The height of the last peak varied from age to age.
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166
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Halpern R, Lee MY, Boulter PR, Phillips RR. A synthesis of nine major reports on physicians' competencies for the emerging practice environment. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 2001; 76:606-615. [PMID: 11401803 DOI: 10.1097/00001888-200106000-00009] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Medical education and training programs generally have been slow to introduce curriculum content that reflects important changes in practice organization and health services delivery. However, impetus for curricular reform is gaining momentum as national organizations endorse new content for both medical school and residency education. The authors and colleagues at Tufts Managed Care Institute reviewed nine reports by key national organizations to assess their positions on curricular reform in light of changes in practice and the system of care. The reports agree generally on the evolving nature of practice, the need to address these changes during medical school and residency training, and the description of the new curriculum content that they advocate. The authors grouped these reports' specific recommendations under ten curriculum domains: health care system overview; population-based care; quality measurement and improvement; medical management; preventive care; physician-patient communication; ethics; teamwork and collaboration; information management and technology; and practice management. They describe the reports' rationales and cite specific knowledge and skills that these national organizations identify within each domain. This domain-based framework synthesizes and complements the recommendations of these national organizations. The authors conclude that implementing curricular reform remains a challenge. The information and competencies need to be organized and sequenced for stage of training and specialty, and barriers to change require strategic and operational planning. Having a common nomenclature and framework will facilitate the introduction of new content within schools and programs, across departments, and among institutions nationwide.
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167
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Seo KK, Kim SC, Lee MY. COMPARISON OF PERIPHERAL INHIBITORY EFFECTS OF CLOMIPRAMINE WITH SELECTIVE SEROTONIN RE-UPTAKE INHIBITORS ON CONTRACTION OF VAS DEFERENS:. J Urol 2001; 165:2110-4. [PMID: 11371937 DOI: 10.1097/00005392-200106000-00079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE We compared the peripheral inhibitory effects of the tricyclic antidepressant clomipramine with those of various selective serotonin re-uptake inhibitors on the contractile response of the vas deferens. MATERIALS AND METHODS The contractile responses of 17 circular smooth muscle strips of human vas deferens to 10-4 M. norepinephrine were observed in the absence and presence of clomipramine, and the selective serotonin re-uptake inhibitors fluoxetine, sertraline and paroxetine. The intraluminal pressure response of rat vas deferens to electrical stimulation of the hypogastric nerve was measured in 5 rats in the central plus peripheral effect group before and after the intravenous injection of 4.2 mg./kg. clomipramine or 8.3 mg./kg. sertraline. The pressure response to each agent was also observed after the transection of all proximal sympathetic input to the hypogastric nerve in 5 animals in the peripheral effect group. RESULTS Clomipramine was about 100-fold more potent than sertraline, fluoxetine or paroxetine for inhibiting the norepinephrine induced contraction of human vasal muscle strips. The inhibitory effect of sertraline on rat intravasal pressure in the peripheral effect group was significantly lower than in the central plus peripheral effect group (p <0.05), while no significant difference was noted in the 2 groups regarding clomipramine. The effect of clomipramine was significantly higher than that of sertraline in the central plus peripheral and peripheral effect groups (p <0.01). CONCLUSIONS Differences in potency of the peripheral inhibitory effects of the selective serotonin re-uptake inhibitors and clomipramine may contribute to their differential effects on delaying ejaculatory latency in patients with premature ejaculation.
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168
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Li B, Lee MY. Transcriptional regulation of the human DNA polymerase delta catalytic subunit gene POLD1 by p53 tumor suppressor and Sp1. J Biol Chem 2001; 276:29729-39. [PMID: 11375983 DOI: 10.1074/jbc.m101167200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The DNA polymerase delta catalytic subunit gene (POLD1) was studied as a transcriptional target of p53. Northern blotting showed that a significantly decreased steady-state level of POLD1 mRNA was associated with increased wild-type p53 expression in cells treated with methyl methanesulfonate. When ectopic wild-type p53 expression was induced to a physiologically relevant level in "tet-off" cultured cells in which p53 expression was tightly regulated by tetracycline, it was found that POLD1 steady-state mRNA was repressed by about 65%. Transient cotransfection experiments using a POLD1 promoter luciferase reporter construct showed that: (i) POLD1 promoter activity was inhibited by transfected wild-type p53 plasmid to a maximum of about 86%; (ii) p53 mediated a large part of the transcriptional repression through a sequence-specific interaction with a site identified as the P4 site of the POLD1 promoter; (iii) tumor-derived p53 mutations in the p53 DNA-binding domain completely abolished the p53 transrepression activity. Moreover, transfection assays demonstrated that p53 was able to repress Sp1-stimulated POLD1 promoter activity and that this repression was largely due to the loss of the sequence-specific interaction between Sp1 protein and the P4 Sp1-binding site, which overlaps the P4 p53-binding site. Finally, gel shift assays suggested that p53 competes with Sp1 protein for binding to the P4 sequence of the POLD1 promoter.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Binding Sites
- Binding, Competitive
- Blotting, Northern
- Blotting, Southern
- Blotting, Western
- DNA Damage
- DNA Polymerase III/genetics
- DNA Polymerase III/metabolism
- Dose-Response Relationship, Drug
- Gene Expression Regulation, Enzymologic
- Genes, p53
- Humans
- Luciferases/metabolism
- Models, Genetic
- Molecular Sequence Data
- Mutation
- Plasmids/metabolism
- Promoter Regions, Genetic
- Protein Binding
- Protein Structure, Tertiary
- Protein Synthesis Inhibitors/pharmacology
- RNA, Messenger/metabolism
- Sequence Homology, Nucleic Acid
- Sp1 Transcription Factor/metabolism
- Tetracycline/pharmacology
- Time Factors
- Transcription, Genetic
- Transfection
- Tumor Cells, Cultured
- Tumor Suppressor Protein p53/metabolism
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169
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Hong ST, Lee MY, Kim SR. Molecular cloning of the anther-preferential nonspecific lipid transfer protein cDNA in hot pepper by mRNA differential display. Mol Cells 2001; 11:241-9. [PMID: 11355707] [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] Open
Abstract
To better understand the molecular control of anther development, an anther-preferential mRNA was isolated from hot pepper (Capsicum annuum) using mRNA differentially display. Using the displayed fragment as a probe, a full-length cDNA named CaLTP was isolated. A nucleotide sequence analysis of CaLTP revealed that the clone contains an open reading frame of 123 amino acids, which exhibits a 60-23% identity with nonspecific lipid transfer proteins (nsLTP). Northern and RT-PCR analysis of the clone confirmed that CaLTP mRNA was predominant to anther tissues. The basal expression level in the leaves was slightly induced only by abscisic acid (ABA) treatment. Southern analysis reveals that CaLTP is present as a single-copy gene in hot pepper genome. We hypothesize that CaLTP might have an important role in protecting the reproductive tissues from environmental stresses.
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170
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Hong S, Lee MY, Cheong J. Functional interaction of transcriptional coactivator ASC-2 and C/EBPalpha in granulocyte differentiation of HL-60 promyelocytic cell. Biochem Biophys Res Commun 2001; 282:1257-62. [PMID: 11302752 DOI: 10.1006/bbrc.2001.4727] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
HL-60 promyelocytic cells were treated with retinoic acid (RA) to stimulate granulocyte differentiation. CCAAT/enhancer binding protein alpha (C/EBPalpha) is known to be the molecular switch during early hematopoietic developmental events that direct cells to the granulocytic pathway. Here we show that the coactivator activating signal cointegrator-2 (ASC-2) plays an important role in differentiation of HL-60 cells into granulocytes by mediating C/EBPalpha-induced gene transcription. The differentiation inducer RA increased mRNA and protein expression of ASC-2. The protein-protein interaction of C/EBPalpha and ASC-2 was detected by coimmunoprecipitation during granulocyte differentiation. Subsequently, GST-pull-down assay revealed that the N-terminal transactivation domain of C/EBPalpha could interact with ASC-2. This functional interaction of ASC-2 with C/EBPalpha drove a synergistic enhancement of C/EBPalpha-dependent transactivation and overexpression of the N-terminal C/EBPalpha protein in HL-60 cells inhibited ASC-2 responsiveness for C/EBPalpha activity in granulocyte differentiation, indicating C/EBPalpha dependency of ASC-2 activity. Taken together, these results suggest that the differentiation-dependent expressed ASC-2 protein physically and functionally interacts with C/EBPalpha and increases its transactivation activity, regulating specific gene transcription for granulocyte differentiation.
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Xu H, Zhang P, Liu L, Lee MY. A novel PCNA-binding motif identified by the panning of a random peptide display library. Biochemistry 2001; 40:4512-20. [PMID: 11284708 DOI: 10.1021/bi010103+] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Proliferating cell nuclear antigen (PCNA) has recently been identified as a target for the binding of proteins involved in DNA replication, DNA repair, and cell cycle control. The interactions between PCNA and a number of these proteins are known to be mediated by a conserved peptide motif. In this study, a random peptide library in which peptide sequences are displayed on the E. coli bacterial flagellin protein was screened for PCNA-binding sequences. Analysis of the retrieved peptide sequences verified the presence of the known PCNA-binding motif. In addition, a second, larger group of peptides containing a different consensus sequence for PCNA binding was discovered. This sequence was found to be present on DNA polymerase delta, and a peptide conforming to this sequence was demonstrated to bind to PCNA. Database search and analysis show that many proteins contain the second consensus sequence. These include proteins that are involved in DNA replication, repair, and cell cycle control. The demonstration of this second PCNA-binding motif may provide a basis for identifying and experimentally testing specific proteins for the structural basis for PCNA binding.
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Lin CC, Lo LJ, Lee MY, Wong HF, Chen YR. Craniofacial surgical simulation: application of three-dimensional medical imaging and rapid prototyping models. CHANG GUNG MEDICAL JOURNAL 2001; 24:229-38. [PMID: 11413880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
BACKGROUND Adequate assessment of the deformity, formulation of good treatment planning, and sufficient rehearsal of procedures before actually performing surgery ensure successful craniofacial surgery. Three-dimensional computed tomography (CT) imaging and facsimile models were used in combination to evaluate their function in craniofacial surgery. METHODS Three-dimensional imaging and facsimile models were used for reconstruction of craniofacial deformity. CT data were acquired, processed, and reconstructed to display 3-dimensional images. The images were used for evaluation of the deformity. The images were then manipulated to create multiple osseous objects. Surgical simulation was performed by moving the computer images. The image processing and manipulation were achieved using the AnalyzePC program. The raw CT data were transformed into a readable format and transferred to produce facsimile models using rapid prototyping technology. The skull models were used for evaluation and surgical simulation. Both methods were compared and used to assist in surgery, which was performed according to the simulations. RESULTS Three-dimensional CT imaging and facsimile models were helpful for simulation of craniofacial surgery. The actual surgery results were satisfactory without complications. Particular advantages were the unlimited trials with the imaging method, and the feeling of reality with the model method. CONCLUSIONS Craniofacial surgery is facilitated by preoperative simulation of procedures. Both 3-dimensional CT imaging and facsimile models are helpful for craniofacial surgical simulation.
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Lee MY, Kong HJ, Cheong J. Regulation of activating transcription factor-2 in early stage of the adipocyte differentiation program. Biochem Biophys Res Commun 2001; 281:1241-7. [PMID: 11243868 DOI: 10.1006/bbrc.2001.4494] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
p38beta mitogen-activated protein kinase activity is required for the differentiation of 3T3-L1 fibroblasts into adipocytes. Activating transcription factor-2 (ATF-2) is efficiently phosphorylated and activated by p38beta kinase. These findings led us to examine a regulatory role of ATF-2 in adipocyte differentiation. The induction of ATF-2 protein precedes the expression of the transcription factors, peroxisome proliferator-activated receptor (PPAR) gamma and CCAAT/enhancer-binding protein (C/EBP) alpha. Consistent with early activation of p38beta kinase, the phosphorylation of ATF-2 was also detected in early stage of adipocyte differentiation. ATF-2 regulated gene transcription of PPARgamma, which was synergistically enhanced by p38beta kinase and C/EBPbeta proteins expression. Ectopic expression of ATF-2 in 3T3-L1 cells induced the endogenous PPARgamma protein levels. These results suggest that ATF-2 plays a role in a primary regulator of adipocyte differentiation with C/EBPbeta through promoting adipogenesis-inducing transcription factors including PPARgamma and becomes associated earlier in the differentiation program as mitotic clonal expansion proceeds and the cells become initially differentiated.
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Lee MY, Chung JH, Shin JH, Hwang TJ, Kim KS, Lee JH, Nam JH, Lee MC, Park CS, Juhng SW, Choi C. Lymphonodular cryptococcosis diagnosed by fine needle aspiration cytology in hyper-IgM syndrome. A case report. Acta Cytol 2001; 45:241-4. [PMID: 11284311 DOI: 10.1159/000327282] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Most cases of cryptococcosis are diagnosed when signs of meningitis have appeared. We report a case of lymphonodular cryptococcosis that was diagnosed by fine needle aspiration cytology (FNAC), excisional biopsy of a cervical lymph node and culture of aspirated material. CASE An 11-year-old boy presented with a history of fever and enlarged bilateral cervical lymph nodes of two weeks' duration. Past medical history included immunoglobulin replacement for hyper-IgM syndrome for the previous eight years. FNAC smears from a cervical lymph node showed numerous yeasts of various sizes, ranging from 5 to 15 microns in diameter, located in the cytoplasm of multinucleated giant cells and in the background. In air-dried, Diff-Quik-stained slides, the yeasts stained blue and were surrounded by clear halos. Aspirated material collected in the syringe was cultured, and Cryptococcus neoformans was isolated. CONCLUSION This case report suggests that a combination of FNAC and culture is a simple and useful method of diagnosing fungal infections. Early diagnosis by FNAC makes possible the early initiation of treatment.
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Lee MY, Rho TH, You KD, Moon GW, Cho EJ, Kim JJ, Kim JH, Hong SJ, Choi KB. The Relationship between QRS duration and LV systolic function in Paced Patients. Korean Circ J 2001. [DOI: 10.4070/kcj.2001.31.3.327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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