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Biomedical subjects

C Y Chon

Publications and source records attributed to C Y Chon.

34 records · Page 2Linked to original sources

Adjuvant effect of polyadenylic.polyuridylic acid on antibody production of recombinant hepatitis B surface antigen in mice.

The adjuvant effect of polyadenylic.polyuridylic acid [poly(A).poly(U)] on antibody production against recombinant hepatitis B surface antigen (rHBsAg) was investigated. Immunization of adult Balb/c mice with rHBsAg plus poly(A).poly(U) elicited significantly higher antibody responses than immunization of mice immunized with rHBsAg alone. Such an adjuvant effect was evident even in mice sensitized with subimmunogenic doses of the antigen.

Adjuvants, Immunologic↗

A case of abdominal cocoon.

Abdominal cocoon is a rare disease of the peritoneum and almost invariably presents as an acute or subacute intestinal obstruction with or without a mass. The etiology of this disease is largely unknown and abdominal cocoon of unknown etiology has been limited to the tropical and subtropical zones and primarily affects young adolescent females. In the temperate zone, only one case has been reported from the United Kingdom, but the patient was also born in Pakistan. No case of abdominal cocoon purely developed in the temperate zone has been reported. Recently, we experienced a case of abdominal cocoon in a 34-year-old female patient(Korean) who had never been abroad. The diagnosis was made postoperatively by reviewing the literature. We herein report this rare condition developed in an unusual geographical location with a brief review of the literature.

Adolescent↗

A large common bile duct stone migrated from the gallbladder through a cholecystohepaticodochal fistula: an unusual complication of Mirizzi syndrome type II.

Mirizzi syndrome with a biliobiliary fistula (Mirizzi syndrome type II) is a rare complication of a long-standing gallbladder stone disease. It is even rarer for a gallbladder stone to migrate through a biliobiliary fistula into the common duct. We encountered this interesting complication of Mirizzi syndrome type II in an 86 year-old female patient. A large gallbladder stone migrated into, and impacted into the distal common bile duct through a cholecystohepaticodochal fistula. The stone was resistant to mechanical lithotripsy and was treated with biliary endoprosthesis and oral bile acids.

Aged↗

Dysphagia due to mediastinal tuberculous lymphadenitis presenting as an esophageal submucosal tumor: a case report.

Mediastinal tuberculous lymphadenitis is rare in adults, and it is even rarer for dysphagia to be the presenting symptom of mediastinal tuberculous lymphadenitis. Mediastinal tuberculous lymphadenitis with esophageal symptoms has been presented as esophageal ulceration, mucosal or submucosal mass with ulceration, fistula or sinus formation, extrinsic compression, or displacement of the esophagus. An exaggerated form of extrinsic compression may be presented as a submucosal tumor, radiologically or endoscopically. A barium esophagography of a 34 year-old woman with painful dysphagia revealed a large submucosal tumor-like mass on the mid-esophagus. The symptom was spontaneously improved over a 3-week period together with reduction of the mass size. A computed tomography of the chest disclosed an enlarged subcarinal lymph node and histologic examination of the specimen obtained by thoracoscopic biopsy brought about a diagnosis of tuberculosis. We herein report a case of mediastinal tuberculosis with unusual manifestations.

Adult↗

Efficacy of polyadenylic.polyuridylic acid in the treatment of chronic active hepatitis B.

In order to assess whether polyadenylic.polyuridylic acid [poly(A).poly(U)] can be used as a new therapeutic agent for the treatment of chronic hepatitis B, 19 patients with histologically proven chronic active hepatitis B were injected intravenously with 100-150 mg of poly(A).poly(U) weekly for six weeks. Changes in alanine aminotransferase (ALT) levels, 2',5'-oligoadenylate synthetase (2'.5'-AS) activities and HBV markers were sequentially checked during and after treatments. Serum ALT levels were decreased gradually and 2'.5'-AS activities were significantly increased after initiation of poly(A).poly(U) injections. At the end of this trial (24th week) we have observed the normalizations of elevated ALT levels in 14 (73.7%), negative conversion of HBeAg in 11 (57.9%) and loss of HBV-DNA in 12 out of 19 patients (63.1%). Complete responses which had both normalization of ALT levels and negative conversion of HBeAg were noted in 11 patients (57.9%) and partial responses showing either normalization of ALT levels or negative conversion of HBeAg alone were in four out of 19 patients (21.1%). No notable adverse effects were observed during the treatments and follow-up period. It can be concluded that poly(A).poly(U) seems to be effective in the treatment of chronic active hepatitis B and has an advantage of being free of significant side effects.

2',5'-Oligoadenylate Synthetase↗

Combined treatment of radiotherapy and hyperthermia for unresectable hepatocellular carcinoma.

Eighty-four patients with unresectable primary hepatocellular carcinoma due either to locally advanced lesion or to association with liver cirrhosis were treated with combined radiotherapy and hyperthermia from April 1988 to January 1991. Purpose of this study was to assess thermometry, response rate, toxicity, and survival in those patients. External radiotherapy was given with a total of 30.6 Gy/3.5 wks. Hyperthermia was given twice a week with a total of 6 treatment sessions using an 8 MHz radiofrequency capacitive type heating machine. Each hyperthermia session was started within 30 min following radiotherapy and continued for 30-60 min. Thermal data were analysed with maximum, minimum, and average temperatures of the tumors. Thermal mapping was also done. In thermometry results, maximum, minimum, and average temperatures of the tumors were 41.9 +/- 1.3 degrees C, 39.9 +/- 1.0 degrees C, and 40.8 +/- 0.9 degrees C, respectively. The fraction over 40 degrees C was 73 +/- 32% with a wide variation from 15% to 100%. Among 67 assessable patients, 27 patients showed tumor regression of more than 50% of the original tumor volume (40.3% response rate). Symptomatic improvement was observed in 78.6% of the patients. Acute toxicities during the treatment were mostly acceptable local pain (51.2%) and local fat necrosis (13.1%). The actuarial 1-year, 2-year, and 3-year survival rates were 44.8%, 19.7%, and 15.6%, respectively. Median survival was 6 months. In view of acceptable toxicities and the current rate of survival, further evaluation of combined treatment of radiotherapy and hyperthermia for unresectable hepatocellular carcinoma is warranted.

Carcinoma, Hepatocellular↗

Effect of anticancer drugs and desferrioxamine in combination with radiation on hepatoma cell lines.

Several anticancer chemotherapeutic agents (5-fluorouracil, adriamycin and cisplatinum) and desferrioxamine, an iron chelator, were tested with regard to cytotoxicity and to the combined effect on radiation induced cell killing using two human hepatoma cell lines (HepG2 and PLC/PRF/5). Survival fractions were measured by quantitative colorimetric assay (MTT assay) and dose-response curves were plotted. MTT assay could be successfully used in the assessment of radiosensitivity in addition to chemosensitivity, because a good linear relationship between optical densities and cell numbers was observed and cells approached exponential growth for the first 7 days of culture when 5 x 10(3) or less cells were inoculated per well in our study. Steepness of the final slope (D0), width of the shoulder (D0) and the extrapolation number (n) of radiation survival curves were 1061.72 rad, 226.43 rad and 1.25 respectively in HepG2 and 1091.38 rad, 268.42 rad and 1.29 respectively in PLC/PRF/5. After combining anticancer chemotherapeutic agents and desferrioxamine with radiation, the widths of the shoulders were decreased whereas sensitizer enhancement ratios were increased as the concentration of drugs increased in both cell lines. These results suggest that neither anticancer chemotherapeutic agents nor desferrioxamine enhance cell killing induced by radiation alone, but suggested the possibility that they inhibit the repair of radiation damage.

Antineoplastic Agents↗

Liver involvement in multiple myeloma proven by peritoneoscopy--a case report.

Liver involvement in multiple myeloma has been known to be common in autopsied series. However, since its clinical significance is uncertain yet, invasive procedure confirming plasma cell infiltration of the liver has been rarely performed. We report a case with multiple myeloma which had plasma cell infiltration of a liver. A peritoneoscopic biopsy of the liver for the purpose of disclosing the nature of the aggravating liver function in a carrier of the hepatitis B virus showed infiltration of lymphoreticular cell which were identified later as lambda-light chain producing primitive plasma cells by immunohistochemical stain.

Adult↗

Histologic study of chronic active hepatitis C; comparison with chronic active hepatitis B.

Reports on the histologic findings of chronic active hepatitis C (CAH-C) have been rare, and the characteristic histologic findings of CAH-C have been not yet determined. To compare the differences in the histologic findings between CAH-C and chronic active hepatitis B (CAH-B) group, we analyzed the histologic findings of 19 patients with CAH-C, who had positive tests for HCV-antibody by EIA, and 19 patients with CAH-B who had negative tests for HCV-antibody but positive tests for HBsAg by RIA. Histologic features were analyzed between the CAH-C and CAH-B groups using a scoring system which is modified from Knodell's histologic activity index-looking at portal inflammation, periportal necroinflammation, portal fibrosis, focal necrosis, regeneration, polyploid nuclear change, sinusoidal lymphocytic reaction and fatty change. Portal inflammatory cell infiltrations with prominent lymphocytes and follicular arrangement were more frequent in the CAH-C group (10 of 19 cases) than in the CAH-B group (5 of 19 cases). Severe sinusoidal lymphocytic reactions were also more prominent in the CAH-C group (11 of 19 cases) than in the CAH-B group (6 of 19 cases). However, periportal necroinflammation, portal fibrosis, focal hepatic necrosis, regeneration and polyploid nuclear changes were more prominent in the CAH-B group than in the CAH-C group. In conclusion, follicular portal inflammation and severe sinusoidal lymphocytic reactions were common histologic findings in serologically proven CAH-C when compared to CAH-B.

Adult↗

Endoscopic injection sclerotherapy in patients with bleeding esophageal varices: a retrospective analysis.

Endoscopic injection sclerotherapy has been accepted as the procedure of choice for patients with variceal hemorrhage. To evaluate the efficiency of endoscopic injection sclerotherapy in patients with bleeding esophageal varices, we did a retrospective study of 52 patients (non-sclerotherapy group) with bleeding esophageal varices who were admitted to hospitals and did not receive sclerotherapy and of 50 patients (sclerotherapy group) who received sclerotherapy with ethanolamine oleate. The mortality (sclerotherapy group vs. non-sclerotherapy group: 18.0% vs. 32.7%) during index hospitalization, the bleeding risk factor (the number of rebleeds per patient/month; 1.56 +/- 2.76 vs. 4.96 +/- 9.99: mean +/- SEM) and the mortality due to bleeding (14.0% vs. 36.5%) were higher in the non-sclerotherapy group than in the sclerotherapy group. Only those in Child's class C who received sclerotherapy had a significantly better survival rate than the non-sclerotherapy group (p less than 0.05). Although formal comparisons were not made because of the retrospective nature of this study, endoscopic injection sclerotherapy is effective and appears to be superior to conventional medical treatments.

Adult↗

Syphilitic gastritis: demonstration of Treponema pallidum with the use of fluorescent treponemal antibody absorption complement and immunoperoxidase stains.

Because of the decrease in the overall incidence of syphilis, syphilitic involvement of stomach is seldom reported in the modern literature. Because of the nonspecific symptoms and signs of the disease, it is necessary to demonstrate Treponema pallidum in the gastric lesions to confirm the diagnosis. With the use of immunofluorescence and immunoperoxidase methods we have succeeded in identifying T. pallidum in the gastric wall of a patient who initially had cutaneous manifestations of secondary syphilis and gastric symptoms.

Adult↗