Biomedical subjects

Jae Woon Choi

Publications and source records attributed to Jae Woon Choi.

5 recordsLinked to original sources

PubMed2006

[A case of leiomyoma in the common bile duct].

Leiomyomas, originating in the bile duct, are very rare, and only few cases have been reported in the literature. We experienced a case of leiomyoma of the distal common bile duct, mimicking bile duct cancer. A 39-year-old woman presented with intermittent jaundice and general weakness for three months. Clinical profiles showed obstructive jaundice, and the abdominal computed tomography and cholangiography revealed diffuse bile duct dilatation with distal common bile duct stricture. A pylorus-preserving pancreaticoduodenectomy was performed and the pathologic specimen disclosed leiomyoma of the common bile duct accompanying severe fibrosis. This is the first case of leiomyoma in the bile duct reported in Korea.

Adult↗

PubMed2006

[A case of primary small cell carcinoma arising from the common bile duct].

Small cell carcinoma is usually seen in the lung, but rarely involves the gastrointestinal tract including biliary tract. A 65 year-old man was admitted because of obstructive jaundice. A smooth-surfaced round intraluminal mass with proximal bile duct dilatation was seen in the proximal common bile duct on endoscopic retrograde cholangiogram. Under the diagnosis of bile duct cancer, pylorus-preserving pancreatoduodenectomy was done. Pathology revealed a 2 cm sized small cell carcinoma in the proximal common bile duct and distal common hepatic duct. On immunohistochemical stain, the tumor cells were positive for neuroendocrine markers CD56 and synaptophysin. After surgery, the patient received 5 cycles of adjuvant chemotherapy with VIP (etoposide, ifosfamide, and cisplatin) regimen. However, the patient died of liver metastasis 12 months after the diagnosis. We report a case of extrapulmonary small cell carcinoma arising from the common bile duct.

Aged↗

PubMed2004

bPAK-interacting exchange factor may regulate actin cytoskeleton through interaction with actin.

p21-activated kinase (PAK)-interacting exchange factor (PIX) is known to be involved in regulation of Cdc42/Rac GTPases and PAK activity. PIX binds to the proline-rich region of PAK, and regulates biological events through activation of Cdc42/Rac GTPase. To further investigate the role of PIX we produced monoclonal antibodies (Mab) against bPIX. Three clones; N-C6 against N-terminal half and C-A3 and C-B7 against C- terminal half of bPIX were generated and characterized. N-C6 Mab detected bPIX as a major band in most cell lines. C-A3 Mab recognizes GIT-binding domain (GBD), but it does not interfere with GIT binding to bPIX. Using C-A3 Mab possible bPIX interaction with actin in PC12 cells was examined. bPIX Mab (C-A3) specifically precipitated actin of the PC12 cell lysates whereas actin Mab failed to immunoprecipitate bPIX. Co-sedimentation of PC12 cell lysates with the polymerized F-actin resulted in the recovery of most of bPIX in the cell lysates. These results suggest that bPIX may not interact with soluble actin but with polymerized F-actin and revealed that bPIX constitutes a functional complex with actin. These data indicate real usefulness of the bPIX Mab in the study of bPIX role(s) in regulation of actin cyoskeleton.

Actin Cytoskeleton↗

PubMed2004

An immunohistochemical study of the expression of adhesion molecules in gallbladder lesions.

We investigated the expression of 10 adhesion molecules (alpha-catenin, beta-catenin, gamma-catenin, CD44, CD44v6, ICAM-1, CD56, CEA, E-cadherin, and CD99) in 46 gallbladder carcinomas, 14 adenomas, 15 low-grade dysplasias, nine intestinal metaplasias, and 20 samples of normal gallbladder epithelium by immunohistochemistry. The expression of adhesion molecules was altered in gallbladder carcinomas and adenomas. In gallbladder carcinomas, increased expression of ICAM-1, CEA, and CD44v6 was observed, together with decreased expression of alpha/beta/gamma-catenin and CD99. In adenomas, aberrant expression of CD44v6 and CD56, as well as reduced expression of alpha/beta/gamma- and E-cadherins, was noted. Expression of alpha/beta/gamma-catenin was reduced in low-grade dysplasia, whereas there was no change in the expression of these adhesion molecules in metaplasia. Expression of ICAM-1, CD99, E-cadherin, and CD56 was correlated with clinical stage. In addition a correlation was noted between expression of ICAM-1 and E-cadherin and lymph node metastasis (p<0.05). These results suggest that altered expression of these adhesion molecules is involved in the progression and metastasis of gallbladder carcinomas.

Adenoma↗

PubMed2002

[An experimental model of hepatic fibrosis induced by alcohol and CCl4: can the lipopolysaccharide prevent liver injury induced by alcohol and CCl4?].

BACKGROUND/AIMS: It is well known that alcohol enhances the toxicity of CCl4. We tried to establish an alcoholic liver cirrhosis model by administration of alcohol and CCl4 to rats. We also wanted to know the hepatoprotective effect of low doses of lipopolysaccharide(LPS) in this animal model. METHODS: Of 20 female adult rats, 8 were ingested with alcohol ad libitum(group 1) Another 6 were ingested with 10% alcohol and 50% 1mL/kg CCl4 intragastrically by Sonde twice a week(group 2) The remaining 6 were ingested with 10% alcohol, CCl4, and 0.1mg/kg LPS intraperitoneally twice a week(group 3) The fibrosis was evaluated semiquantitatively on a scale of 0(none) to 3(cirrhosis). RESULTS: 1) After 10 weeks, septal fibrosis or cirrhosis was produced in 9 out of 12 rats in groups 2 and 3 but there was no fibrotic change in group 1. 2) There was no significant difference in pathological grading between groups 2 and 3. CONCLUSIONS: Hepatic fibrosis or cirrhosis can be sufficiently induced by alcohol and repetitive CCl4 ingestion for 10 weeks. We can not prove the hepatoprotective effect of low dose LPS by semiquantitative evaluation of pathological grading.

Animals↗