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Biomedical subjects

S Y Song

Publications and source records attributed to S Y Song.

At least 37 records · Page 2Linked to original sources
PubMed2001

Liver abscess after transcatheter oily chemoembolization for hepatic tumors: incidence, predisposing factors, and clinical outcome.

PURPOSE: To evaluate the incidence of, predisposing factors for, and clinical outcome of liver abscess developing in patients with hepatic tumors after transcatheter oily chemoembolization (TOCE). MATERIALS AND METHODS: During the past 6-year period, 2,439 patients with hepatic tumors underwent a total of 6,255 TOCE procedures. With a retrospective review of medical records, the authors evaluated the occurrence of liver abscess, the statistical significance of potential predisposing factors including portal vein obstruction, metastatic tumors, biliary abnormalities (type 1, simple biliary obstruction; type 2, status prone to ascending biliary infection), malignant gastrointestinal mucosal lesions, and additional gelatin sponge particle embolization in liver abscess formation, and the clinical outcome of abscess. RESULTS: Fifteen liver abscesses occurred in 14 patients (0.2%). Liver abscesses developed in three of 987 (0.3%) TOCE procedures for portal vein obstruction, three of 114 (2.6%) procedures for metastatic tumors, one of 49 (1.8%) for type 1 biliary abnormality, four of 55 (7.4%) for type 2 biliary abnormality, two of 18 (11.1%) for malignant gastrointestinal mucosal lesion, and nine of 2,108 (0.4%) for additional gelatin sponge particle embolization. Univariate and multivariate statistical analysis showed that type 2 biliary abnormality was a significant predisposing factor. The mortality related to liver abscess occurred in two patients (13.3%). Thirteen liver abscesses were successfully treated with parenteral antibiotics and percutaneous catheter drainage. However, irreversible deterioration of liver function occurred in two patients. Two of nine further TOCE procedures in three patients caused recurrent septicemia and liver abscess. CONCLUSION: The biliary abnormality prone to ascending biliary infection was the most important predisposing factor to the development of liver abscess after TOCE. Postembolic liver abscess could be effectively managed with percutaneous catheter drainage.

Anti-Bacterial Agents↗
PubMed2001

CHOP followed by involved field radiation: is it optimal for localized nasal natural killer/T-cell lymphoma?

The present study aimed to analyse the treatment outcome of four cycles of CHOP (cyclophosphamide-vincristine-doxorubicin-prednisolone) followed by involved field radiation therapy (IF RT) for the treatment of stage I-II nasal natural killer (NK)/T-cell lymphoma. From March 1995 to December 1999, 17 patients (median age 41 years; range 30-66) with localized nasal NK/T-cell lymphoma were enrolled. B symptoms were noted in five patients (31%). Sixteen of seventeen patients (94%) were of low risk when classified according to the International Prognostic Index (IPI). The treatment plan consisted of four cycles of CHOP chemotherapy followed by IF RT of 45 Gy. Two patients received radiation during the first or second cycle of CHOP because of bleeding from the primary tumour site. Both patients achieved complete responses (CRs). In the remaining 15 patients, after 4 cycles of CHOP, 6 CRs and 3 partial responses (PRs) were achieved (53% of response rate). IF RT was given to six patients (four in CR, one in PR and one in PD), and all six patients achieved CR. Overall, CR was achieved in 10 of 17 patients (58%). The planned sequential chemoradiotherapy was completed in only 6 of 17 patients (35%) because of the progression during chemotherapy. None of the patients who achieved CR experienced relapse of lymphoma during follow-up. The estimated overall three-year survival rate was 59%. In univariate analysis, B symptoms and stage were significant prognostic factors for response and overall survival (P < 0.05). The present study suggests that four cycles of CHOP followed by IF RT is not satisfactory for treating patients with localized nasal NK/T-cell lymphoma, and that further exploration for improved therapy is needed.

Adult↗
PubMed2001

Expression of p21Waf1, p27Kip1 and cyclin D1 proteins in breast ductal carcinoma in situ: Relation with clinicopathologic characteristics and with p53 expression and estrogen receptor status.

p21Waf1 (p21), p27Kip1 (p27) and cyclin D1 have recently been reported as useful prognostic markers for patients with breast carcinoma. However, studies on these cell cycle regulators in ductal carcinoma in situ (DCIS) have been extremely limited. Therefore, we studied the immunohistochemical expression of p21, p27 and cyclin D1 proteins in 49 DCIS cases and compared the findings with the clinicopathologic parameters (age, tumor size, gross type, histologic type, histologic grade, necrosis and mitotic index), p53 and estrogen receptor (ER) status. A significant correlation was found between positive p21 immunoreactivity (67.3% of the cases) and well-differentiated histologic grade, non-comedo type, ER-positive and p53-negative (p53-) status. DCIS with p21+/p53- is likely to be the non-comedo type. The overexpression of cyclin D1 (59.2% of the cases) correlated positively with the ER expression (P = 0.001). The p27 protein expression (46.9% of the cases) correlated with the cyclin D1 immunopositivity (P = 0.0003) and ER expression (P = 0.005). No significant associations were seen in the p27 or cyclin D1 expression and other clinicopathologic parameters. Our results suggest that p21 might be more related to the useful biologic markers in DCIS than p27 or cyclin D1. The significant positive association between p21, p27 or cyclin D1 and ER status, and close association of p27 and cyclin D1 expression might be implicated in the tumor biology of DCIS.

Adult↗
PubMed2001

Aortic and arterial aneurysms in behçet disease: management with stent-grafts--initial experience.

PURPOSE: To assess the application of stent-grafts in the management of aortic and arterial aneurysms in patients with Behçet disease. MATERIALS AND METHODS: Nine aneurysms in seven patients were managed with various types of stent-grafts. Diagnoses were based on clinical findings. The aortic aneurysms (n = 3) were thoracic (n = 1), suprarenal (n = 1), or infrarenal (n = 1). The arterial aneurysms (n = 6) were in the right and left subclavian (n = 2), right common carotid (n = 2), right brachiocephalic (n = 1), or left common iliac arteries (n = 1). A tandem connection of Gianturco stent covered with polytetrafluorethylene was placed in three aneurysms, and a balloon-expandable stent was placed in six. RESULTS: The stent-graft was successfully placed in all patients. Immediate follow-up angiography revealed complete exclusion of the aneurysm in all cases. Follow-up computed tomography performed 3 days to 2 weeks later revealed complete exclusion and thrombosis of the aneurysm and patency of the stent-graft in six patients. In one patient, total occlusion of the artery with a stent occurred due to flow disturbance caused by double lesions. During follow-up (range, 6-59 months; mean, 28 months), the aneurysm resolved and completely regressed in four patients. A recurrent aneurysm at the distal margin of previously inserted stent-graft was successfully managed with an additional stent-graft. CONCLUSION: The findings in this initial experience suggest that stent-graft insertion may be a safe and effective alternative to surgical treatment of aortic and arterial aneurysms in patients with Behçet disease.

Adult↗
PubMed2001

Preoperative uterine artery embolization and evacuation in the management of cervical pregnancy: report of two cases.

Preoperative uterine artery embolization and cervical evacuation as conservative management of cervical pregnancy has been tried in recent years. However, cervical suturing, vasoconstrictor injection, or cervical ballooning was frequently used as an ancillary measures in those procedures in most of the previous studies. We report two cases of cervical pregnancy that were successfully treated with preoperative uterine artery embolization and removal of gestational material without ancillary procedures. Our therapeutic modality seems to be safe and effective for conservative management of cervical pregnancy.

Adult↗
PubMed2000

Regulation of IL-1beta-mediated MUC2 gene in NCI-H292 human airway epithelial cells.

This study demonstrates for the first time the effects of IL-1beta on the regulation of protein production as well as MUC2 gene transcription in cultured human airway epithelial cells. The effect of IL-1beta on the regulation of MUC2 protein was determined by flow cytometric analysis. The expression level of MUC2 induced by IL-1beta increased in a dose-dependent manner. MUC2 transcripts were detected after 2 h of exposure to IL-1beta and reached maximal level after 8 h. Actinomycin D experiments indicated that the IL-1beta-mediated MUC2 expression was controlled by transcriptional regulation. Both RT-PCR and FACS analysis showed that budesonide concomitantly attenuated IL-1beta mediated MUC2 gene as well as protein production levels. Use of the glucocorticoid receptor antagonist, RU-486, restored the inhibitory effect of budesonide on the IL-1beta-mediated MUC2 protein as well as gene. The data suggest that IL-1beta up-regulates MUC2 gene by transcriptional regulation and that budesonide suppresses the IL-1beta-medicated MUC2 expression via decreased transcriptional activation.

Bronchodilator Agents↗
PubMed2000

Cell adhesive sequences in mouse laminin beta1 chain.

Laminin-1, a major component of the basement membrane, consists of three different chains, alpha1, beta1, and gamma1. We sought to identify cell adhesive sequences from the mouse laminin beta1 chain by testing HT-1080 fibrosarcoma and B16-F10 melanoma cells for binding to 187 overlapping synthetic peptides which covered the entire chain. Fourteen peptides showed cell adhesive activities with either peptide-conjugated Sepharose beads or peptide-coated plates or both. Additional cells, including neuronal, endothelial, and salivary gland cells, showed biological responses in a cell type-specific manner. B-7, B-133, and B-160 showed the most potent cell attachment. Cell binding on three peptides (B-34, B-133, and B-160) was inhibited by EDTA. Cell adhesion to 11 of the 12 active peptides was inhibited to varying degrees by heparin. Of the 17 active peptides identified in the laminin beta1 chain in this and other studies, 8 are clustered on the amino terminal globular domain, suggesting a possible important role in cell binding for this domain that may be multifunctional. These data demonstrate that the laminin beta1 chain has multiple active sites for cell adhesion, some of which are cell-type specific.

Amino Acid Sequence↗
PubMed2000

Presynaptic impairment of cerebellar inhibitory synapses by an autoantibody to glutamate decarboxylase.

Glutamic acid decarboxylase (GAD), the enzyme responsible for converting glutamate to gamma-aminobutyric acid (GABA), is a target of humoral autoimmunity in stiff-man syndrome and subacute cerebellar ataxia. Recently, we found that an anti-GAD autoantibody in the CSF of an ataxic patient selectively suppressed GABA-mediated transmission on cerebellar Purkinje cells without affecting glutamate-mediated transmission. Here, we examine the mechanism by which the autoantibody impaired the inhibitory transmission, using immunohistochemistry and whole-cell recording in rat cerebellar slices. The present results indicate that CSF immunoglobulins prepared from an ataxic patient acted on the presynaptic terminals of GABAergic interneurons and decreased GABA release onto Purkinje cells.

Action Potentials↗
PubMed2000

Structure of apo-glyceraldehyde-3-phosphate dehydrogenase from Palinurus versicolor.

d-Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) shows cooperative properties for binding coenzymes. The structure of apo-GAPDH from Palinurus versicolor has been solved at 2.0 A resolution by X-ray crystallography. The final model gives a crystallographic R factor of 0.178 in the resolution range 8 to 2 A. The structural comparison with holo-GAPDH from the same species reveals a conformational change induced by coenzyme binding similar to that observed in Bacillus stearothermophilus GAPDH but to a lesser extent. The differences in magnitude during the apo-holo transition between these two enzymes were analyzed with respect to the change of the amino acid composition in the coenzyme binding pocket. In the crystalline state of apo-GAPDH, the overall structures of the subunits are similar to each other; however, significant differences in temperature factors and minor differences in domain rotation upon coenzyme binding were observed for different subunits. These structural features are discussed in relation to the environmental asymmetry of crystallographically independent subunits.

Animals↗
PubMed2000

Reduced expression of the cell-cycle inhibitor p27Kip1 is associated with progression and lymph node metastasis of gastric carcinoma.

AIMS: p27Kip1 (p27), a cyclin-dependent kinase inhibitor, plays an important role as inhibiting the progression of the cell cycle. Decreased expression of p27 is associated with high histological grade and aggressiveness of several human tumours. We aimed to evaluate the role of p27 in the progression and metastasis of gastric carcinoma. METHODS AND RESULTS: We analysed the expression of p27 in 67 primary gastric carcinomas and 31 lymph node metastases by immunohistochemistry. Reduced expression of p27 was found more frequently in advanced gastric cancer (40.9%) than in early gastric cancer (15.6%) (P < 0.001). Decreased p27 expression correlated with large tumour size, high histological grade, lymphatic invasion, advanced stage, deep invasion, lymph node metastasis and recurrence. The expression of p27 showed an inverse correlation with the Ki67 labelling index. There was a significant reduction of p27 expression in metastatic tumour cells in lymph nodes (mean positive cells: 3. 7%) when compared to the corresponding primary gastric carcinomas (mean positive cells: 8.1%) (P = 0.008). CONCLUSIONS: Alterations of p27 expression may play an important role in the progression and metastasis to lymph node of tumour cells in human gastric carcinoma.

Biomarkers, Tumor↗
PubMed2000

Endoscopic snare resection for tumors of the ampulla of Vater.

Though surgical resection has been the traditional treatment for tumors of the ampulla of Vater, endoscopic maneuvers such as snare resection, laser photodestruction and electrofulguration have recently been introduced to avoid operation-related morbidity and mortality. From 1994 to 1996, 6 patients with ampullary tumor were managed by endoscopic snare resection and regularly followed. Endoscopic snare resection of the ampullary tumor was technically feasible in all patients and each procedure was performed in a single session. Histologic diagnoses of the resected specimens were adenoma in 4 patients and adenoma with coexistent adenocarcinoma in 2 patients. Resection margins were negative in all patients except 1 with coexistent adenocarcinoma and a radical pancreaticoduodenectomy was performed in that case. For the other patient with adenocarcinoma foci, no further treatment was persued since he was 72-year-old and refused operation. Acute pancreatitis developed in 2 patients after endoscopic therapy, but was resolved with conservative management. There was no procedure-related death. Surveillance duodenoscopy performed at 1 and 6 months after endoscopic resection revealed no evidence of recurrent tumor in 4 patients with adenoma. Among them, 3 patients are alive without evidence of recurrence at 16-37 months after resection, but 1 patient was lost after 9 months of follow-up. The patient with adenocarcinoma in whom a pancreaticoduodenectomy was performed, has been alive without recurrence for 12 months. Oral 5-fluorouracil was administered for the other patient with adenocarcinoma foci. Though he experienced local recurrence at 13 months after the procedure, he has been alive for 28 months after resection. In conclusion, endoscopic snare resection may be applied as a viable alternative to surgery in selected patients with small ampullary tumors.

Aged↗
PubMed2000

A case of minute intraductal papillary mucinous tumor of the pancreas presenting with recurrent acute pancreatitis.

Intraductal papillary mucinous tumor (IPMT) of the pancreas, a lesion consisting of mucin-producing cells with neoplastic potential, is characterized by duct ectasia, mucin hypersecretion, often extensive papillary intraductal growth, varying degrees of cytologic atypia, and relatively indolent growth. The clinical presentation of IPMT of the pancreas is characterized by chronic or recurrent attacks of abdominal discomfort often in association with low level pancreatic enzyme elevations. Less commonly these lesions may be detected as asymptomatic radiographic abnormalities. Interestingly, a case of a minute IPMT (2 mm in height and 7 mm in length, adenoma) in the main pancreatic duct presenting with acute pancreatitis in a 55 year-old man has been reported in the Japanese literature. Recently, we also experienced a case of a minute IPMT in a branch pancreatic duct causing repeated bouts of acute pancreatitis in a 75 year-old man. A filling defect at the neck of the main pancreatic duct seen on an endoscopic retrograde pancreatogram performed after recovery of the second attack of acute pancreatitis led the patient to undergo an exploratory laparotomy. After a near-total pancreatectomy was carried out, a minute (3 x 7 mm) IPMT of borderline malignancy was discovered in a branch duct at the head portion near the pancreatic neck without any lesions in the main pancreatic duct. Surprisingly, despite the resective surgery the patient died of carcinomatosis 8.5 months after the operation. We herein report a case of a minute but aggressive IPMT of the pancreas with a review of the literature.

Acute Disease↗
PubMed1999

Helicobacter pylori strain-specific genotypes and modulation of the gastric epithelial cell cycle.

Helicobacter pylori cag+ strains enhance gastric epithelial cell proliferation and attenuate apoptosis in vivo, which may partially explain the increased risk of gastric cancer associated with these strains. The goals of this study were to identify specific H. pylori genes that regulate epithelial cell cycle events and determine whether these effects were dependent upon p53-mediated pathways. AGS gastric epithelial cells were cultured alone or in the presence of 21 clinical H. pylori isolates, H. pylori reference strain 60190, or its isogenic cagA-, picB-, vacA-, or picB-/vacA- derivatives. Coculture of H. pylori with AGS cells significantly decreased cell viability, an effect most prominent with cag+ strains (P < 0.001 versus cag-strains). cag+ strains significantly increased progression of AGS cells from G1 into G2-M at 6 h and enhanced apoptosis by 72 h. Compared with the parental 60190 strain, the picB- mutant attenuated cell cycle progression at 6 h (P < or = 0.05), and decreased apoptosis with enhanced AGS cell viability at 24 h (P < or = 0.04). The vacA- mutant decreased apoptosis and enhanced viability at later (48-72 h) time points (P < or = 0.05). Compared with the wild-type strain, the picB-/vacA- double mutant markedly attenuated apoptosis and increased cell viability at all time points (P < or = 0.05). Furthermore, cocolonization with H. pylori had no significant effect on expression of p53, p21, and MDM2. The diminished AGS cell viability, progression to G2-M, and apoptosis associated with cag+ H. pylori strains were dependent upon expression of vacA and genes within the cag pathogenicity island. These results may explain heterogeneity in levels of gastric epithelial cell proliferation and apoptosis found within H. pyloricolonized mucosa.

Apoptosis↗
PubMed1999

Identification of metastasis-promoting sequences in the mouse laminin alpha 1 chain.

Laminin-1, a major basement membrane matrix glycoprotein, enhances adhesion, migration, and metastasis of tumor cells. We have screened 208 overlapping synthetic peptides covering the short and long arms of mouse laminin alpha1 chain for their adhesion activity with B16-F10 mouse melanoma cells. Cell adhesion activity was determined using various amounts of peptides coated on plastic dishes and by measuring cell adhesion on peptide-conjugated Sepharose beads. Nineteen peptides showed B16-F10 cell adhesion activity. Three peptides, designated A-13, -24, and -208, showed the strongest attachment activity in the plate assay, whereas 4 peptides, A-13, -51, -99, and -112, demonstrated the strongest cell adhesion when conjugated to beads. The 19 peptides were tested in vivo for their effect on experimental pulmonary metastasis by B16-F10 cells. Four peptides, A-13, -51, -64, and -119, significantly enhanced metastasis, with A-13 showing the strongest dramatic enhancement. The four metastasis-promoting peptides also stimulated migration of B16-F10 cells in the Boyden chamber assay in vitro with A-13 being the most potent stimulator. In addition, the 4 peptides inhibited laminin-induced cell attachment and migration, which indicates that these four sequences are possible functional B16-F10 cell binding sites in laminin-1. All the four sequences are located on the globular domains of the short arm. Other peptides, including strong adhesion-active peptides, A-24, -99, -112, and a scrambled A-13 peptide, did not stimulate either migration or metastasis. Thus, laminin-1 has multiple active sites in the globular domains of the short arm which promote migration and metastasis of B16-F10 cells.

Animals↗
PubMed1999

Establishment and characterization of 12 human colorectal-carcinoma cell lines.

In this article, we describe the characteristics of 12 human colorectal-carcinoma cell lines established from 6 primary tumors and 6 metastatic sites of 11 Korean colorectal-carcinoma patients, including the morphology in vivo and in vitro and mutations of K-ras2, p15, p16, p53, APC, beta-catenin, hMLH1 and hMSH2 genes in vitro. No lines were contaminated with Mycoplasma or bacteria. All lines were proven to be unique by DNA-fingerprinting analysis. All lines expressed the surface carcino-embryonic antigen and secreted it into the supernatant fluid. The morphological correlation between the original tumors and cultured cells suggested that the original tumors showing mucinous adenocarcinoma correlated with floating aggregates in culture, and degree of desmoplasia in the original tumor correlated with attached growth in culture. Five of the cell lines showed mutations in the K-ras2 gene, and 6 of the cell lines showed mutations in the p53 gene. The p15 gene was deleted in 2 cell lines, and the p16 gene was hypermethylated in 3 cell lines. The mutation of mismatch-repair genes (hMLH1 and hMSH2) was found in 4 lines, the APC gene and beta-catenin gene were mutated in 9 and 2 lines respectively. These well-characterized colorectal-cancer cell lines should serve as useful tools for investigating the biological characteristics of colorectal cancer.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Structure of active site carboxymethylated D-glyceraldehyde-3-phosphate dehydrogenase from Palinurus versicolor.

The structure of active site carboxymethylated D-glyceraldehyde-3-phosphate dehydrogenase from Palinurus versicolor was determined in the presence of coenzyme NAD+ at 1.88 A resolution with a final R-factor of 0.175. The structure refinement was carried out on the basis of the structure of holo-GAPDH at 2.0 A resolution using the program XPLOR. The carboxymethyl group connected to Cys149 is stabilized by a hydrogen bond between its OZ1 and Cys149N, and charge interaction between the carboxyl group and the nicotinamide moiety. The modification of Cys149 induced conformational changes in the active site, in particular, the site of sulphate ion 501 (the proposed attacking inorganic phosphate ion in catalysis), and segment 208-218 nearby. Extensive hydrogen-bonding interactions occur in the active site, which contribute to the higher stability of the modified enzyme. The modification of the active site did not affect the conformation of GAPDH elsewhere, including the subunit interfaces. The structures of the green and red subunits in the asymmetric unit are nearly identical, suggesting that the half-site reactivity of this enzyme is from ligand-induced rather than pre-existing asymmetry. It is proposed that the carboxymethyl group takes the place of the acyl group of the reaction intermediate, and the catalytic mechanism of this enzyme is discussed in the light of a comparison of the structures of the native and the carboxymethylated GAPDH.

Animals↗
PubMed1999

An immunohistochemical analysis of heat shock protein 70, p53, and estrogen receptor status in carcinoma of the uterine cervix.

OBJECTIVES: It has been shown that heat shock proteins (HSPs) protect cells from death caused by various noxious stimuli. Overexpression of HSP70 seems to be related to hormonal regulation of cell proliferation and/or down-regulation of sex steroid receptors. Wild-type p53 has been reported to repress HSP70 gene expression. It has been shown that mutant p53-HSP70 complex is highly expressed in cancer. However, the relationship between HSPs and steroid receptors or tumor suppressor gene products has not been well understood in uterine cervical carcinoma. This study was undertaken to examine the expression of HSP70, estrogen receptor (ER), and p53 in carcinoma of the uterine cervix. In addition, we analyzed HPV infection status and compared it to such immunohistochemical parameters. We also analyzed the relationship between these biological products and their clinicopathologic characteristics. METHODS: Paraffin-embedded tissue sections were obtained from 84 patients with carcinoma of the uterine cervix. Expression of HSP70, p53, and ER was evaluated by immunohistochemical staining using anti-HSP70 monoclonal antibody (SPA810), anti-p53 (BP53.12), and ER1D5 antibody, respectively. PCR HPV detection was done by dot hybridization method. RESULTS: Positive staining of HSP70 was detected in 73% of the cases. HSP70 positivity was significantly higher in stage I cervical cancer than in stages II-IV (P = 0.02). This was associated with neither tumor size, lymph node status, parametrial involvement status, nor tumor markers (TA-4). Furthermore, there was no significant correlation between HSP70 positivity and the expression of p53 or ER or HPV infection status. CONCLUSION: These data suggested that HSP70 positivity was frequent in uterine cervical cancer, especially in the early stages. However, this was not significantly correlated with clinicopathologic characteristics nor with the expression of p53 or ER nor with HPV infection in carcinoma of the uterine cervix.

Female↗