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Yoo JS, Cheun BS, Park IS, Song YC, Seo Y, Kim NG, Shin HW, Lee JH. Use of sodium transfer tissue biosensor (STTB) for monitoring of marine toxic organism. JOURNAL OF ENVIRONMENTAL BIOLOGY 2004; 25:431-6. [PMID: 15907072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A highly sensitive sodium (Na+) transfer tissue biosensor (STTB) was designed using a frog bladder membrane to measure paralytic shellfish poisons (PSP). The STTB consists, of a Na+ electrode covered by the membrane, which was then integrated into a flow-through system for continuous measurements. In the absence of Na+ channel blocker, active transfer of Na+ occurred from inside to outside across the frog membrane. When the STTB was used to measure the Na+ -dependent dissociation of PSP, it was able to detect PSB at a level contained in a single cell. However, 5 fg or higher (100 cells or more) is needed for accurate and reproducible measurements. The toxicity obtained by the STTB was significantly correlated (r = 0.9449) to that determined by the HPLC. Therefore, the simple method of the STTB can be used not only to detect a low level PSP in toxic plankton populations, but also to monitor poisons in shellfish.
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Ko JK, Ban JE, Kim YH, Park IS. Long-term efficacy of atenolol for atrioventricular reciprocating tachycardia in children less than 5 years old. Pediatr Cardiol 2004; 25:97-101. [PMID: 14648002 DOI: 10.1007/s00246-003-0536-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Atrioventricular reciprocating tachycardia (AVRT) using an accessory pathway is the most common supraventricular tachycardia observed in infancy and childhood. There is a general agreement to treat children older than 5 years who are on a potentially long-term antiarrhythmic agent with radiofrequency catheter ablation. Atenolol, a relatively long-acting and cardioselective beta-adrenoceptor blocker, has been used to control the various types of supraventricular tachycardia in children and adults. There are few reports on the use of atenolol in children <5 years old with AVRT. This retrospective study reports our experience in 22 children <5 years old (median age, 20 months) who received atenolol monotherapy between 1995 and 2001 for treatment of AVRT. AVRT was confirmed in 17 patients by transvenous or transesophageal electrophysiologic study and in 5 patients by documented preexcitation on electrocardiograms. In nine patients atenolol was the first antiarrhythmic drug given. In 15 of the 22 patients (68%) therapy with atenolol was considered successful. The average effective dose of atenolol in these 15 patients was 1.2 +/- 0.3 mg/kg/day. During a median follow-up of 41 months (8-74 months), atenolol had been discontinued in 10 patients and no further attacks of tachycardia occurred except in 1 patient. In no case did the drug have to be withdrawn for adverse effects. In conclusion, this retrospective study shows that atenolol as a monotherapy is efficient and relatively safe in the long-term treatment of AVRT in young children. Atenolol can be recommended as a first-line treatment option for the management of AVRT in infants and young children.
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Kim HJ, Kim JE, Ha M, Kang SS, Kim JT, Park IS, Paek SH, Jung HW, Kim DG, Cho GJ, Choi WS. Steroidogenic acute regulatory protein expression in the normal human brain and intracranial tumors. Brain Res 2003; 978:245-9. [PMID: 12834921 DOI: 10.1016/s0006-8993(03)02840-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study we found the expression of steroidogenic acute regulatory protein (StAR) mRNA and protein in both the normal human brain and intracranial tumors, using RT-PCR and immunohistochemistry. StAR mRNA is expressed at a very low level in the white matter of the normal human brain, but in tumoral tissues StAR mRNA was specifically expressed in oligodendrogliomas and malignant glial tumors. StAR-positive cells were also detected in the normal human brains and gliomas; its frequency and density were higher in glioma tissue. These findings suggest that StAR expression might be correlated with the growth of glial tumors.
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Kim NR, Suh YL, Shin HJ, Park IS. Gliofibroma with extensive calcified deposits. Clin Neuropathol 2003; 22:14-22. [PMID: 12617189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Gliofibroma is a rare astrocytic neoplasm of young people that shows abundant deposition of collagenous matrix around glial cells. It shares some clinical and pathologic features with desmoplastic cerebral astrocytoma of infancy or desmoplastic infantile ganglioglioma. However, histogenesis or clinical behavior of these tumors is not fully known. Here, we report a case of gliofibroma with unusual extensive calcification which complicated radiologic as well as pathologic diagnosis.
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Paiva SAR, Yeum K, Lee KS, Park IS, Lee‐Kim YC, Russell RM. Endogenous carotenoid concentrations in cancerous and non‐cancerous tissues of gastric cancer patients in Korea*. Asia Pac J Clin Nutr 2002; 8:160-6. [DOI: 10.1046/j.1440-6047.1999.00087.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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81
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Son JI, Park HJ, Song KS, Kim KJ, Lee CY, Lee SI, Park IS. A single center's 30 years' experience of esophageal adenocarcinoma. Korean J Intern Med 2001; 16:250-3. [PMID: 11855155 PMCID: PMC4578062 DOI: 10.3904/kjim.2001.16.4.250] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Adenocarcinoma of the esophagus has been reported to be increasing in incidence in a number of regions throughout the world, while the incidence of squamous cell carcinoma (SCCA) of the esophagus is mostly stable or decreasing. To evaluate the increasing tendency of adenocarcinoma of the esophagus. METHODS We studied retrospectively the records of patients with histologically proven esophageal cancer between 1970 and 1999 at the Yonsei Medical Center. RESULTS Total cases of esophageal cancer were 969 patients of which the cases of adenocarcinoma and SCCA were 27 patients and 918 patients, respectively. The ratio of esophageal adenocarcinoma to SCCA was 0.0375 in the 1970s, 0.0241 in the 1980s and 0.0292 in the 1990s. There was no statistical difference (p = 0.811) in the ratios of adenocarcinoma of the esophagus between the three consecutive 10-year groups. CONCLUSION In conclusion, unlike the US and other western countries, it seems that the ratio of esophageal adenocarcinoma compared to SCCA has not increased among patients with esophageal carcinoma at the Yonsei Medical Center.
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Kim BM, Han YM, Shin YJ, Min BH, Park IS. Clusterin expression during regeneration of pancreatic islet cells in streptozotocin-induced diabetic rats. Diabetologia 2001; 44:2192-202. [PMID: 11793021 DOI: 10.1007/s001250100029] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS Beta-cell regeneration has been reported after islet injury in an animal model for diabetes. Recently, we showed up-regulation of clusterin after islet injury and suggested that clusterin might be involved in cytoprotection and in the regeneration of islet cells. The aim of this study was to investigate the correlation of clusterin expression with islet regeneration and its effect on islet cell replication. METHODS Streptozotocin was administrated to rats to induce various types of diabetes. Islet regeneration and clusterin expression were examined after islet injuries. Clusterin cDNA was transfected to MIN6 cells and their proliferation activity was measured by a [3H]thymidine-incorporation assay. RESULTS A diabetogenic dose of streptozotocin injected in rats provoked an immediate degeneration of beta cells. In this model, islets showed increased clusterin expression with extensive proliferation of alpha cells but showed poor beta-cell replication. A subdiabetogenic dose of streptozotocin, however, led to the proliferation of beta cells with clusterin up-regulation. In streptozotocin-treated neonatal rats, up-regulation of clusterin was noted during beta-cell proliferation. In all experimental models, clusterin was expressed in alpha cells in close correlation with islet cell proliferation, higher transcription of insulin mRNA and MAPKs activation. Cell replication was increased by 31 % in the MIN6 cells transfected by the clusterin cDNA. CONCLUSION/INTERPRETATION Up-regulation of clusterin in alpha cells might induce beta-cell proliferation and thus restore their population after islet injury. We suggest that clusterin could be considered as a growth factor-like molecule stimulating islet-cell proliferation by paracrine action.
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Kim YM, Yoo SJ, Kim TH, Park IS, Kim WH, Kim SH, Lee YT. Tracheal compression by elongated aortic arch in patients with congenitally corrected transposition of the great arteries. Pediatr Cardiol 2001; 22:471-7. [PMID: 11894148 DOI: 10.1007/s002460010277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We investigate the tracheal compression by aortic arch in patients with congenitally corrected transposition of the great arteries. Fourteen patients whose ascending aorta was connected to descending aorta on the contralateral side were divided into two groups according to the severity of tracheal compression on lateral angiogram: group 1 (stenosis > or = 50%, eight patients) and group 2 (stenosis < 50%, six patients). We compared the following variables between the groups: aortic size, lateral displacement of ascending aorta, retrosternal space, and contour of aortic arch. Spiral computed tomography (CT) was done in five patients of group 1. The ratio between measured and normal diameters of ascending aorta of group 1 was significantly larger than that of group 2 (1.57 +/- 0.14 compared to 1.19 +/- 0.26, p = 0.014). There was linear correlation between the tracheal compression and aortic size (r = 0.69, p = 0.001). The ascending aorta was positioned more laterally and the aortic arch was located more posteriorly in group 1. In four patients with decreased tracheal compression after surgery, aortic size decreased and the ascending aorta restored its anterior position. Spiral CT showed transversely oriented aortic arch and severe tracheal compression in the anteroposterior direction by aortic arch. The tracheal compression by aortic arch in corrected transposition is common when the descending aorta is located on the contralateral side of the ascending aorta. Aortic size, posterior position, elongation, and end-on appearance of the aortic arch are the useful predictors of tracheal compression.
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Park IS, Lee YC, Park HJ, Kim TI, Lee SI, Kim H, Chung KS, Lee-Kim YC. Helicobacter pylori infection in Korea. Yonsei Med J 2001; 42:457-70. [PMID: 11519091 DOI: 10.3349/ymj.2001.42.4.457] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Helicobacter pylori is a gram-negative bacterium that was first isolated in 1982. Since then, H. pylori infection in humans has been shown to be associated with gastritis, peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma as well. The epidemiology, transmission, and pathogenicity of H. pylori has been a subject of intensive study. Successful treatment improves the cure rate of peptic ulcerations and treatment with antimicrobials also decreases the recurrence rate of these diseases. Better regimens having less toxicity and a good eradication rate have also been developed. A better understanding of the pathophysiologic mechanisms relating to H. pylori induced mucosal damages would result in more options for the prevention of peptic ulcers and carcinogenesis. Korea has a relatively high incidence of H. pylori infection and gastric cancer. Growing interest has developed in view of its importance in being associated with various gastroduodenal diseases. Furthermore, along with a high incidence of H. pylori-related disease in Korea, because the interaction between H. pylori, host factors and environmental factors is important in disease pathogenesis, we need to have precise data on the characteristics of H. pylori-related diseases that occur in Korea. In the present report we review the epidemiology, transmission route, diagnosis, pathogenesis, treatment methods and relationship with gastroduodenal diseases with in special references to basic and clinical data that have been published.
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Kim TI, Lee YC, Lee KH, Han JH, Chon CY, Moon YM, Kang JK, Park IS. Effects of nonsteroidal anti-inflammatory drugs on Helicobacter pylori-infected gastric mucosae of mice: apoptosis, cell proliferation, and inflammatory activity. Infect Immun 2001; 69:5056-63. [PMID: 11447186 PMCID: PMC98600 DOI: 10.1128/iai.69.8.5056-5063.2001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2001] [Accepted: 04/29/2001] [Indexed: 01/04/2023] Open
Abstract
Helicobacter pylori and nonsteroidal anti-inflammatory drugs (NSAIDs) are two well-known important causative factors of gastric damage. While H. pylori increases apoptosis and the proliferation of gastric epithelial cells and is an important factor in peptic ulcer and gastric cancer, NSAIDs induce cell apoptosis and have antineoplastic effects. We investigated the effects of NSAIDs (a nonselective cyclooxygenase [COX] inhibitor [indomethacin] and a selective COX-2 inhibitor [NS-398]) on the apoptosis and proliferation of gastric epithelial cells and gastric inflammation in H. pylori-infected mice. C57BL/6 mice were sacrificed 8 weeks after H. pylori SS1 inoculation. Indomethacin (2 mg/kg) or NS-398 (10 mg/kg) was administered subcutaneously once daily for 10 days before sacrifice. The following were assessed: gastric inflammatory activity, gastric COX protein expression by Western blotting; gastric prostaglandin E(2) levels by enzyme immunoassay, apoptosis by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling, and cell proliferation by Ki67 immunostaining. Compared to the controls, H. pylori infection and/or NSAID treatment increased COX-1 and COX-2 protein expression. Gastric prostaglandin E(2) levels, apoptotic index, cell proliferation index, neutrophil activity, and the degree of chronic inflammation were all increased by H. pylori infection, and these effects were significantly decreased by indomethacin treatment. However, NS-398 treatment after H. pylori infection did not induce a significant reduction, although it did result in a tendency to decrease. These results show that NSAIDs can reverse the increased apoptosis and proliferation of epithelial cells and inflammatory activity in the stomachs of H. pylori-infected mice and that, like COX-2 activation, COX-1 induction contributes to the change of gastric mucosal cell turnover and inflammation induced by H. pylori infection.
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Abstract
The aims of this study were to investigate the clinical and colonoscopic characteristics of patients with intestinal Behçet's disease and to compare the findings of typical and atypical intestinal Behçet's disease. Ninety-four patients diagnosed as having intestinal Behçet's disease were included. Of these, we considered 42 patients as having complete or incomplete type; these fulfilled the international criteria as "typical," and the other 52 patients were classified as having "atypical" intestinal Behçet's disease. Abdominal pain was the most common symptom (92%), followed by diarrhea and gastrointestinal bleeding. All of the 22 patients with a history of surgery had ulcers at the anastomotic site. Most of the patients, who had never been operated on, had lesions in the ileocecal area (96%). Sixty-three patients (67%) had a single ulcer. Many (76%) of the ulcers were larger than 1 cm, and the mean size of the ulcers was 2.9 cm. Most (99%) of the ulcers were round/oval or geographic in shape. Usually ulcers were deep (62%), and their margins discrete (80%). There was no difference in the endoscopic findings of typical and atypical intestinal Behçet's disease. Typical colonoscopic findings in intestinal Behçet's disease were single or a few deep ulcers with discrete margins in the ileocecal area or anastomotic site. Endoscopic characteristics of patients with intestinal involvement in the case of "suspect" or "possible" type of Behçet's disease that lack the systemic manifestations of Behçet's disease were in accord with those in "complete" or "incomplete" types of Behçet's disease, who fulfill the International Study Group for Behçet's Disease criteria.
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Kim N, Park IS. Purification of saponin compounds in Bupleurum falcatum by solvent partitioning and preparative LC. Biosci Biotechnol Biochem 2001; 65:1648-51. [PMID: 11515551 DOI: 10.1271/bbb.65.1648] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Saponin compounds (saikosaponin c, a, and d) in Bupleurum falcatum were partially purified by solvent partitioning of the herbal extract using diethyl ether, distilled water, n-butanol, and acetone. After separation of the saponins by preparative LC, the purity of each saikosaponin was more than 94%. The identities of purified individual saikosaponins were confirmed by TLC, analytical LC, and fast-atom bombardment mass spectrometry.
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Kim MK, Park IS, Park HD, Wee WR, Lee JH, Park KD, Kim SH, Kim YH. Effect of poly(ethylene glycol) graft polymerization of poly(methyl methacrylate) on cell adhesion. J Cataract Refract Surg 2001; 27:766-74. [PMID: 11377910 DOI: 10.1016/s0886-3350(00)00701-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To investigate the effect of surface modification of poly(methyl methacrylate) (PMMA) by poly(ethylene glycol) (PEG) grafting on cell adhesion. SETTING Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea. METHODS The PMMA surface was oxidized with ozone, and PEG acrylate was then graft polymerized. To verify the PEG grafting on the surface, the oxygen content was measured by electron spectroscopy for chemical analysis. The contact angle was measured using the Wilhelmy plate method. The adhesion of keratocytes on modified PMMA was investigated in vitro. Cultured rabbit keratocytes (4 x10(5) cells/mL) were layered on each PMMA disk, cultured in a carbon dioxide incubator for 24 hours, harvested by trypsinization, and counted. A commercially available intraocular lens was modified as described and then inserted in the anterior chamber of a white rabbit. The cell adherence pattern on the modified IOL was examined by scanning electron microscopy. RESULTS The PEG-grafted PMMA revealed a higher oxygen content and lower dynamic receding contact angles than the untreated PMMA. The mean number of adhered cells was 72.5 +/- 22 x 10(4)/mL for untreated PMMA. After PEG grafting of 1 hour and ozone oxidation of 2 hours, the adherent cell counts significantly decreased to 6.5 +/- 1.7 x 10(4)/mL and 7.6 +/- 1.6 x 10(4)/mL, respectively (P =.002). Scanning electron microscopy showed small round cells sparsely scattered on the modified PMMA in contrast to the untreated PMMA. CONCLUSION Surface modification of PMMA using PEG grafting reduced cell adhesion. This may decrease the incidence of retroprosthetic membrane formation after keratoprosthesis surgery.
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Goo YS, Lee YC, Shin MS, Kim WH, Kim H, Park IS. A case of Cronkhite-Canada syndrome involving the entire gastrointestinal tract. Endoscopy 2001; 33:385. [PMID: 11315906 DOI: 10.1055/s-2001-13694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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Ahn J, Park IS, Lee KS, Kim SY, Chung EJ, Kim J, Kim DJ, Yoon S, Lee-Kim YC. Fatty acid patterns in gastric mucosa of stomach cancer patients. Yonsei Med J 2001; 42:220-6. [PMID: 11371111 DOI: 10.3349/ymj.2001.42.2.220] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
omega6 and omega3 fatty acids are important cellular components and known to be involved in disease processes. However, few studies have focused on mucosa fatty acid in human gastric cancer. The purpose of this study was to investigate how fatty acid patterns of mucosa are altered in gastric cancer. Fatty acids were analyzed by gas chromatography and their relative compositions (%) were determined and evaluated both in mucosa total-fatty acids and in phospholipid-fatty acids in paired cancerous and non-cancerous gastric cancer tissues (n = 18). The level of arachidonic acid (20:4omega6, AA) appeared significantly higher both in phospholipid-fatty acids (p < 0.05) and in total-fatty acids (p < 0.001) in cancerous mucosa compared to non-cancerous mucosa. The omega6/omega3 fatty acid ratio of phospholipid-fatty acids was also significantly higher in cancerous mucosa. The higher level of AA in cancerous tissue can be partially explained by the higher ratio of 20:4omega 6/20:3omega6 (desaturation index) and the lower ratio of 22:4omega6/20:4 omega6 (elongation index). The change in the relative composition of arachidonic acid may influence the production of prostaglandins and related metabolites, which regulate cell differentiation and proliferation. The findings of this study with respect to fatty acid changes, especially in terms of arachidonic acid metabolism, may be of relevance in the understanding of the roles of specific fatty acids and possibly of eicosanoids in gastric cancer.
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Jho HD, Park IS, Alfieri A. The future of pituitary surgery. CLINICAL NEUROSURGERY 2001; 47:83-98. [PMID: 11197729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Moon IS, Park IS, Schenker LT, Kennedy MB, Moon JI, Jin I. Presence of both constitutive and inducible forms of heat shock protein 70 in the cerebral cortex and hippocampal synapses. Cereb Cortex 2001; 11:238-48. [PMID: 11230095 DOI: 10.1093/cercor/11.3.238] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Heat shock proteins serve as molecular chaperones in a protein "holding and folding" system. Protein sequencing, extraction and immunoblot analyses indicate that Hsc70, a constitutive form, is a major component of the rat postsynaptic density (PSD) fraction, while Hsp70, an inducible form, is present at the basal level. Immunohistochemical studies show that expression of Hsc70 is high, but that of Hsp70 is low, in the cerebral cortex and hippocampal formation. In dissociated hippocampal neurons, both Hsp70 and Hsc70 immunoreactivities are distributed throughout the soma and dendrites. In dendrites, there are many stained puncta which are mostly co-localized with PSD-95, a postsynaptic marker. Interestingly, variation in staining intensity of the puncta is significantly larger for Hsp70 than for Hsc70 in 2-week-old cultures, but becomes less significant in 5(1/2)-week-old cultures. At the electron microscopic level, both Hsp70 and Hsc70 are mainly associated with asymmetrical PSDs. However, Hsc70 is also associated with amorphous subsynaptic structures and spine apparatus-like cisternae. Our data indicate that both Hsp70 and Hsc70 are present in PSDs but are differentially distributed at subsynaptic sites, and provide a potential candidate system for a "synaptic tag".
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Ryoo R, Park IS, Jun S, Lee CW, Kruk M, Jaroniec M. Synthesis of ordered and disordered silicas with uniform pores on the border between micropore and mesopore regions using short double-chain surfactants. J Am Chem Soc 2001; 123:1650-7. [PMID: 11456764 DOI: 10.1021/ja0038326] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Silica molecular sieves with uniform pores on the borderline between micropore (diameter <2 nm) and mesopore (from 2 to 50 nm) ranges were synthesized by a novel method using judiciously chosen mixtures of short double-chain alkylammonium surfactants. These silicas were characterized using X-ray diffraction (XRD), thermogravimetry, and nitrogen and argon adsorption. The calcined materials exhibited either 2-dimensional (2-D) hexagonal or disordered structures with XRD interplanar spacing from 2.51 to 2.93 nm, including the value of as small as 2.69 nm for highly ordered 2-D hexagonal silica. The dependence of the pore size and surfactant content on the surfactant chain length provided strong evidence for supramolecular templating being operative in the formation of small-pore silicas, even for the surfactant chain length of six carbon atoms. Both hexagonally ordered and disordered calcined samples were shown to exhibit narrow pore size distributions with maxima in the range from 1.96 to 2.61 nm (reliably evaluated on the basis of the unit-cell dimension and pore volume for 2-D hexagonal materials, and calculated using a properly calibrated procedure), tailored by the surfactant chain length. The samples exhibited primary pore volumes from 0.28 to 0.54 cm(3) g(-1) and specific surface areas from 730 to 930 m(2) g(-1). Because of their small yet uniform pore size and large specific surface area, the silicas reported herein promise to be useful in applications in adsorption and catalysis. Adsorption studies of these materials provided a unique new insight into the pore-filling mechanism for small-pore materials. Moreover, the approach proposed herein is expected to facilitate the synthesis of not only small-pore silicas but also materials with other framework compositions, thus largely contributing to bridging the gap in attainable pore sizes between micropore and mesopore ranges.
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Jang HD, Chung YM, Baik JH, Choi YG, Park IS, Jung YK, Lee SY. Caspase-cleaved TRAF1 negatively regulates the antiapoptotic signals of TRAF2 during TNF-induced cell death. Biochem Biophys Res Commun 2001; 281:499-505. [PMID: 11181075 DOI: 10.1006/bbrc.2001.4369] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Tumor necrosis factor (TNF) signaling leads to pleiotropic responses in a wide range of cell types, in part by activating antiapoptotic and proapoptotic pathways. Previous studies have suggested that TNF receptor-associated factor (TRAF) 2 can mediate crucial antiapoptotic signals during TNF stimulation. However, it is unclear how the antiapoptotic signals via TRAF2 in TNF-R1 signaling is regulated. Here we show that TRAF1 is cleaved by caspase-8 into two fragments during apoptosis induced by TNF. Overexpression of the C-terminal cleavage product, TRAF1-c, increased TNF-induced cell death of hybridoma T cells. Importantly, we demonstrate that the cleavage product of TRAF1 coimmunoprecipitates with TRAF2 that is released from the TNF-R1 complex in response to prolonged TNF treatment. These results indicate that caspase-dependent cleavage of TRAF1 generates TRAF1-c fragments that are able to bind TRAF2, and then sequester TRAF2 from the TNF-R1 complex, rendering cells, at least in part, sensitive to TNF.
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Choi SW, Chung JP, Song YK, Park YN, Chu JK, Kim DJ, Jung JH, Lee CH, Lee SJ, Park HJ, Lee KS, Lee SI, Park IS, Sohn SK. Lower gastrointestinal bleeding due to cytomegalovirus ileal ulcers in an immunocompetent man. Yonsei Med J 2001; 42:147-51. [PMID: 11293496 DOI: 10.3349/ymj.2001.42.1.147] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Cytomegalovirus (CMV) infections are commonly reported in severely immunocompromised hosts and ulcers of the alimentary tract are frequently observed in systemic CMV infections. However, invasive and ulcerative disease of the gastrointestinal (GI) tract caused by CMV has also been reported in healthy adults. Many reports show that a CMV infection can produce localized ulcerations in the esophagus, stomach, small intestine, and colon in nonimmunocompromised individuals. The most common site of involvement by CMV infection in the GI tract is the colon followed by the upper GI tract and the least common site is the small intestine. Although GI bleeding is one of the major presenting symptoms of patients with CMV infections of the GI tract, lower GI bleeding due to CMV ileal ulcers in immunocompetent patients, to our knowledge, has not been reported in the English literature. Recently, we experienced a case of lower GI bleeding due to CMV ileal ulcers in a 57-year-old man who had no evidence of immunocompromise. This case suggests that small intestinal ulcers due to CMV infection should be included in the differential diagnosis of lower GI bleeding even in immunocompetent hosts.
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Abstract
Repeated trauma to the ear very often results in "cauliflower ear." Many methods have been suggested to prevent an injured ear from demonstrating a cauliflowerlike deformity. The principles of treatment are evacuation of the hematoma, control of the reaccumulation of fluid, and maintenance of the cartilage contour. The authors studied the effect of ionizing radiation on deformed rabbit ears induced by repeated trauma. Twenty ears (10 rabbits) were used in the experiment. The animals were divided into four groups (control, preradiation, low dose, and high dose). Hematoma was produced by pounding the lateral side of the auricle 10 times with a 50-g weight at a height of 15 cm. The thickness of the injured and uninjured sites was measured, and histological analysis was performed for each group. The thickness of the ears of the irradiated groups was significantly less than the control group. The authors think that radiation treatment of repeatedly injured ears could prevent ear deformity, and could possibly be an adjunctive form of management of cauliflower ear in addition to hematoma evacuation and compression therapy.
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Divino CM, Park IS, Angel LP, Ellozy S, Spiegel R, Kim U. A retrospective study of diagnosis and management of mesenteric vein thrombosis. Am J Surg 2001; 181:20-3. [PMID: 11248170 DOI: 10.1016/s0002-9610(00)00532-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Mesenteric vein thrombosis (MVT) is an uncommon type of intestinal ischemia associated with significant mortality and morbidity because of its delay in diagnosis. METHODS A retrospective analysis of 9 patients treated surgically for MVT during 1982 to 1997 was performed. RESULTS Nine patients underwent surgical therapy for intestinal ischemia due to MVT. The most common presenting symptom was abdominal pain with bloody diarrhea in 3 patients; preoperative diagnosis of MVT was suspected in 2. Radiologic tests included plain roentgenograms, computed axial tomography, and ultrasound. Time to surgery ranged from 3 hours to 7 days after admission. All patients underwent resection of infarcted bowel with primary anastomosis and immediate postoperative anticoagulation. No patient underwent a second-look operation. The postoperative morbidity and mortality rates were 55% and 11%, respectively. CONCLUSION Diagnosis of intestinal ischemia from MVT is often delayed, and strong clinical suspicion and aggressive treatment are necessary in its management.
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Lee SJ, Kim JH, Kim YM, Lee GK, Lee EJ, Park IS, Jung JM, Kang KH, Shin T. Perfusion MR imaging in gliomas: comparison with histologic tumor grade. Korean J Radiol 2001; 2:1-7. [PMID: 11752962 PMCID: PMC2718089 DOI: 10.3348/kjr.2001.2.1.1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the usefulness of perfusion MR imaging in assessing the histologic grade of cerebral gliomas. MATERIALS AND METHODS In order to determine relative cerebral blood volume (rCBV), 22 patients with pathologically proven gliomas (9 glioblastomas, 9 anaplastic gliomas and 4 low-grade gliomas) underwent dynamic contrast-enhanced T2*-weighted and conventional T1- and T2-weighted imaging. rCBV maps were obtained by fitting a gamma-variate function to the contrast material concentration versus time curve. rCBV ratios between tumor and normal white matter (maximum rCBV of tumor / rCBV of contralateral white matter) were calculated and compared between glioblastomas, anaplastic gliomas and low-grade gliomas. RESULTS Mean rCBV ratios were 4.90 degrees +/- 1.01 for glioblastomas, 3.97 degrees +/- 0.56 for anaplastic gliomas and 1.75 degrees +/-1.51 for low-grade gliomas, and were thus significantly different; p <.05 between glioblastomas and anaplastic gliomas, p <.05 between anaplastic gliomas and low-grade gliomas, p <.01 between glioblastomas and low-grade gliomas. The rCBV ratio cutoff value which permitted discrimination between high-grade (glioblastomas and anaplastic gliomas) and low-grade gliomas was 2.60, and the sensitivity and specificity of this value were 100% and 75%, respectively. CONCLUSION Perfusion MR imaging is a useful and reliable technique for estimating the histologic grade of gliomas.
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Kim SJ, Bae EJ, Cho DJ, Park IS, Kim YM, Kim WH, Kim SH. Development of pulmonary arteriovenous fistulas after bidirectional cavopulmonary shunt. Ann Thorac Surg 2000; 70:1918-22. [PMID: 11156095 DOI: 10.1016/s0003-4975(00)02164-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND A high incidence of pulmonary arteriovenous fistulas (PAVF) has been reported after bidirectional cavopulmonary shunt (BCPS) or total cavopulmonary shunt (TCPS; BCPS in patients with interrupted inferior vena cava). However, the definite diagnostic criteria or standard diagnostic modality of PAVF has not yet been defined. The goal of this study was to evaluate the diagnostic modalities and the prevalence of PAVF. METHODS We selected 10 patients with TCPS and 27 patients with BCPS. Lung perfusion scan, contrast echocardiogram, and pulmonary angiogram were performed. The results were compared among groups of patients and among each diagnostic modality. RESULTS All 10 patients with TCPS and 16 and 13 patients with BCPS showed positive results on contrast echocardiograms and lung scans, respectively. Six patients with TCPS and 4 patients with BCPS showed positive results on pulmonary angiograms. All patients with TCPS developed subclinical or clinical PAVF and 19 patients with BCPS developed subclinical PAVF and none of them had clinical PAVF during the short-term follow-up. CONCLUSIONS Most patients with bidirectional cavopulmonary anastomosis have subclinical evidence of right-to-left intrapulmonary shunting. This problem can be demonstrated with various diagnostic modalities.
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Kim WH, Cho YJ, Park JY, Min PK, Kang JK, Park IS. Factors affecting insertion time and patient discomfort during colonoscopy. Gastrointest Endosc 2000; 52:600-5. [PMID: 11060182 DOI: 10.1067/mge.2000.109802] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Successful colonoscopy depends on insertion of the instrument to the cecum, precise observation, and minimal patient discomfort during the procedure. The aim of this prospective study was to determine whether certain variables are associated with insertion time and patient discomfort during colonoscopy. METHODS Nine hundred nine consecutive colonoscopic examinations performed by a single endoscopist in patients without obstructive disease of the colorectum were analyzed. Four liters of Colonlyte (Taejun, Seoul, Korea) were used for bowel cleansing, and meperidine (25 mg) was administered intramuscularly 10 minutes before the procedure. The degree of patient discomfort was assessed using a 5-level Likert scale. RESULTS Among 909 study patients, colonoscopy was completed to the cecum in 876 patients (96.4%). The adjusted completion rate was 98% and mean insertion time for complete colonoscopy was 6.9+/-4.2 minutes. Colonoscopy caused less patient discomfort than barium enema or esophagogastroduodenoscopy. Multivariate logistic regression analysis demonstrated that inadequate bowel cleansing, advanced age, and constipation as an indication are independent factors associated with prolonged insertion time (>10 minutes). Female gender was the only independent factor associated with significant discomfort (> or = level 4) during colonoscopy. CONCLUSIONS Among the factors affecting insertion time and patient discomfort during colonoscopy, unsatisfactory bowel preparation was the only correctable factor.
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