Showing papers by "Won Ho Kim published in 2001"

Colonoscopic findings in intestinal Behçet's disease.

Abstract: The aims of this study were to investigate the clinical and colonoscopic characteristics of patients with intestinal Behcet's disease and to compare the findings of typical and atypical intestinal Behcet's disease. Ninety-four patients diagnosed as having intestinal Behcet'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 Behcet'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 Behcet's disease. Typical colonoscopic findings in intestinal Behcet'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 Behcet's disease that lack the systemic manifestations of Behcet's disease were in accord with those in "complete" or "incomplete" types of Behcet's disease, who fulfill the International Study Group for Behcet's Disease criteria.

Additive activation of hepatic NF-kappaB by ethanol and hepatitis B protein X (HBX) or HCV core protein: involvement of TNF-alpha receptor 1-independent and -dependent mechanisms.

Abstract: Alcohol consumption and viral hepatitis infection synergistically accelerate liver injury, but the underlying mechanism is not fully understood. Here we have examined the effects of ethanol on hepatitis B protein X (HBX)- or hepatitis C core protein (HCV core protein)-mediated activation of NF-kappaB, a critical signal in hepatic injury, regeneration, and tumor transformation. Acute ethanol or acetaldehyde exposure potentiates HBX or HCV core protein activation of NF-kappaB in primary mouse hepatocytes. Such potentiation can be abolished by blocking ethanol metabolism or overexpression of dominant negative NF-kappaB-inducing kinase (NIK), IkappaB kinase (IKK), or IkappaB. Moreover, pertussis toxin attenuates NF-kappaB activation induced by acetaldehyde but not by HBX or HCV core protein, whereas HBX or HCV core protein-mediated activation of NF-kappaB is abolished completely in tumor necrosis factor a receptor 1 (TNFR1) (-/-) hepatocytes. Finally, chronic ethanol consumption induces hepatic CYP2E1 protein expression and potentiates HBX or HCV core protein activation of NF-kappaB in the liver. These findings suggest that ethanol activates hepatic NF-kappaB via its metabolism and that HBX or HCV core protein activates hepatic NF-kappaB via TNFR1. With the essential role of TNFR1 in alcoholic liver injury, targeting TNFR1 by hepatitis viral proteins could contribute to cooperative effects of alcohol consumption and viral hepatitis on liver disease.

Prolonged activation of mitogen-activated protein kinases during NSAID-induced apoptosis in HT-29 colon cancer cells.

Abstract: The mechanisms of the antineoplastic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) still are unknown, but the induction of apoptosis is one of the possible mechanisms. We attempted to demonstrate the role of mitogen-activated protein (MAP) kinases, generally considered to be important mediators of proliferative and apoptotic signals, in NSAID-induced colon cancer cell apoptosis. Apoptosis was detected by demonstration of DNA fragmentation in agarose gel electrophoresis. Cell death was assessed by trypan blue dye exclusion method. MAP kinase activation was assessed by Western blot using phosphospecific antibodies to MAP kinases. Kinase assay using activating transcription factor-2 (ATF-2) fusion protein as a substrate was also performed for measuring p38 MAP kinase activity. For the inhibition of p38 MAP kinase, pyridinylimidazole compound (SB203580) was utilized. Caspase-3 activity was measured using the tetrapeptide fluorogenic substrate Ac-DEVD-AMC. Treatment of HT-29 cells with NSAIDs results in time- and dose-dependent induction of apoptosis, accompanied by sustained activation of all three MAP kinase subfamilies. The SB203580, a p38 MAP kinase inhibitor, reduced indomethacin-induced cell death by 43%, while PD098059, a MAPK/ERK kinase (MEK)1 inhibitor, did not affect cell death. p38 MAP kinase and caspase-3 activation were not significantly interlinked in indomethacin-induced apoptosis. From these results, we conclude that NSAIDs can induce prolonged activation of MAP kinases in colon cancer cells and that, of these, p38 MAP kinase may play a partial but significant role in indomethacin-induced apoptosis.

Isolation Trend of Enteropathogenic Bacteria in 1969-1998.

Abstract: Background : Diarrheal disease has been one of the most common health problem in Korea with Salmonella and Shigella being the major bacterial pathogens. Prevalence of enteric bacterial pathogens may differ significantly depending on the socioeconomic status of a country. Therefore, rapid improvement of living conditions in Korea should have profound effect on the incidence of enteric infection. In some Salmonella infections, proper antimicrobial treatment is important to reduce morbidity and mortality, but rapid change of the susceptibility makes the susceptibility unpredictable. So, there is a need to describe the change of antimicrobial susceptibility of Salmonella. Methods : In this study, stool culture results at Severance Hospital during the years 1969-1998 were analyzed to determine the trends of enteric bacterial isolation and the susceptibility of the isolates. Results : The proportion of S. typhi was reduced to 1.4% in 1994-1998. The proportion of Shigella was over 50% of all enteric pathogens until 1983, while only 14 strains were isolated during the last 5 years. Campylobacter spp. became the second most prevalent organism with the decrease of Shigella isolation. Ampicillinand cotrimoxazole-susceptible nontyphoidal Salmonella gradually decreased to 76% and 90%, respectively in 1994-1998 and even several extended-spectrum βlactamase-producing strains were detected. Strains of ampicillin-resistant S. typhi were first detected in 1995. Conclusions : Typhoid fever and shigellosis are rare disease now in urban clinical setting while nontyphoidal Salmonella infection is a prevalent one. Campylobacter is the second most common enteric bacterial pathogen. With the increase of antimicrobial resistance of nontyphoidal Salmonella and appearance of resistant S. typhi, difficulties in the treatment of these infections may be expected in the future. (Korean J Clin Microbiol 2001;4(2):87-95)

Intestinal Behçet's disease: breath-hold MR imaging.

Abstract: Background: To determine the feasibility of magnetic resonance (MR) imaging in the evaluation of intestinal Behcet's disease. Methods: Eight patients diagnosed to have intestinal Behcet's disease prospectively underwent MR imaging. Five patients had previously undergone abdominal surgery for intestinal Behcet's disease 27–81 months previously. Breath-hold T2-weighted single-shot fast spin echo, T1-weighted multiplanar spoiled gradient recalled echo, and postgadolinium-enhanced fat-suppressed T1-weighted opposed-phase multiplanar spoiled gradient recalled echo images were obtained. MR findings were analyzed by three independent radiologists in terms of the presence and location of bowel wall thickening and ulcer, maximal bowel wall thickness, grade of bowel wall enhancement, and presence and nature of extraluminal manifestations. K statistics were used to evaluate interobserver variability. Results: Seven cases (88%), including the five cases with previous operations, demonstrated bowel thickening of more than 9 mm and increased enhancement. Ulcer was depicted in four cases (50%) in the terminal ileum or an anastomosis site. Three cases (38%) showed extraluminal manifestation, such as mesenteric infiltration around the involved bowel (two cases) and a sinus tract to subhepatic abscess from perforation (one case). Conclusion: Breath-hold MR imaging is useful for the evaluation of bowel wall thickening, enhancement, mesentery infiltration, and abscess formation. Characteristic ulcerative lesions may be also depicted on T1- and T2-weighted breath-hold images. MR imaging is a useful method for postoperative follow-up study for the evaluation of recurrence.

A case of Cronkhite-Canada syndrome involving the entire gastrointestinal tract.

Abstract: We encountered a case of a 56-year-old woman with Cronkhite±Canada syndrome who presented with chronic diarrhea, alopecia, intermittent abdominal pain, hyperpigmentation, and nail dystrophy (Figure 1). Her face, palms, and the back of her hands and soles of her feet were deeply pigmented with small dark brown spots. Her family history was noncontributory. Serum total protein was 5.4 g/dl, with 2.4 g/dl of albumin. Endoscopic examination of the stomach showed multiple sessile polyps, varying in size from 2 mm to 10 mm throughout the entire stomach and duodenum (Figure 2). Small-bowel x-ray and colonoscopic examination revealed multiple polyps from the jejunum to the rectum. Histopathologic examination of these polyps revealed edema of the lamina propria, and mucosal erosion associated with evidence of chronic inflammation. Scintigraphy with technetium-99m-labeled human albumin demonstrated a proteinlosing enteropathy. Hyperalimentation (2200kcal/d) was continued for 8 weeks. At 1 week later, the patient s diarrhea showed a decrease in severity, with improvement in appetite and weight gain. However, the diarrhea recurred after 2 weeks. After administration of prednisolone, 30 mg daily, and trimethoprim with sulfamethoxazole (Bactrim), clinical improvement was noted, with cessation of diarrhea, increased serum protein, disappearance of pigmentation, and regrowth of the scalp hair.

Separation of Goid, Palladium and Platinum in Chromite by Anion Exchange Chromatography for Inductively Coupled Plasma Atomic Emission Spectrometric Analysis

Abstract: A study has been carried out on the separation of gold, iridium, palladium, rhodium, ruthenium and platinum in chromite samples and their quantitative determination using inductively coupled plasma atomic emission spectrometry (ICP-AES). The dissolution condition of the minerals by fusion with sodium peroxide was optimized and chromatographic elution behaviour of the rare metals was investigated by anion exchange chromatography. Spectral interference of chromium, a matrix of the minerals, was investigated on determination of gold. Chromium interfered on determination of gold at the concentration of 500 mg/L and higher. Gold plus trace amounts of iridium, palladium, rhodium and ruthenium, which must be preconcentrated before ICP-AES was separated by anion exchange chromatography after reducing Cr(VI) to Cr(III) by H2O2. AuCl4 - retained on the resin column was selectively eluted with acetone- HNO 3-H2O as an eluent. In addition, iridium, palladium, rhodium and ruthenium remaining on the resin column were eluted as a group with concentrated HCl. However, platinum was eluted with concentrated HNO3. The recovery yield of gold with acetone-HNO3-H2O was 100.7 ± 2.0%, and the yields of palladium and platinum with concentrated HCl and HNO3 were 96.1 ± 1.8% and 96.6 ± 1.3%, respectively. The contents of gold and platinum in a Mongolian chromite sample were 32.6 ± 2.2 μg/g and 1.6 ± 0.14 μg/g, respectively. Palladium was not detected.

Foaming Characteristics and Physical Properties of Ethylene Vinyl Acetate Copolymer Foams

Abstract: Physical properties of foams depend on the density of foams, Physical properties of base polymers, open ceil contents, and cell structures including the size, size distribution, shape of ceil and the thickness of membrane and strut. The density of foam is affected by raw materials, concentration oi crosslinking agent and blowing agent and process parameters such as processing technique and condition. Ethylene vinyl acetate copolymer(EVA) foam is a crosslinked cellular material. The foaming characteristics and physical properties of EVA foam are affected by decomposition rate of blowing agent. In this study, the decomposition rate of blowing agent and crosslinking rate, foaming characteristics and physical properties of foams were evaluated. The slow decomposition rate of blowing agent results in low density foam, good shock absorption property and uniform cell size distribution compared to the high decomposition rate of blowing agent.