Clinicopathologic Study on Clear Cell Hepatocellular Carcinoma / 한국간담췌외과학회지

BACKGROUND: Clear cell hepatocelluar carcinoma (CHCC) is a well defined type of hepatocellular carcinoma (HCC) in which a large number of tumor cells have clear cytoplasm that is not stained by hematoxylin and eosin stain. It is generally reported that CHCC has a favorable prognosis compared with that of conventional non-CHCC.1 The reasons for the better prognosis are not clear. To date the clinicopathologic features of CHCC of the liver have not been fully elucidated. In the present study we compared the clinicopathologic features of 56 cases of CHCC with those of 479 cases of non-CHCC and report here hoping to further understanding of CHCC. METHODS: 535 consecutive cases that were curatively resected from Jan. 1992 to Dec. 1997 in Seoul National University Hospital were reviewed. The cases were divided into clear cell HCC (56 cases) and non-clear cell HCC (479 cases). Clinical and pathological findings were compared between two groups. RESULTS: Clinically there is no significant difference in sex or =2) of clear cell HCC was 3.8% (2/56), lower than the finding of 13.1% (62/479) for non-clear cell HCC. (p<0.05) CONCLUSION: It was concluded that clear cell HCC has no significant difference in clinicopathologic features except tumor number.

A 12-year Experience from 1990 to 2001 in Performing Curative Hepatic Resection for Hepatocellular Carcinoma / 한국간담췌외과학회지

BACKGROUND/AIMS: Hepatic resection is an accepted therapeutic modality for hepatocellular carcinoma (HCC). In the present study, surgical results are analyzed with an aim toward further improving the treatment of HCC. METHODS: We reviewed 831 patients with HCC who underwent a curative hepatic resection in Seoul National University Hospital from 1990 to 2001. We analyzed age, sex, GOT/ GPT, alpha-fetoprotein (alpha FP), HBsAg, anti-HCV, Child classification, size and number of tumor, extent of resection, resection margin, and perioperative transfusion. RESULTS: 1-, 3-, and 5-year overall survival rates were 91.1%, 79.8%, and 71.7%. 1-, 3-, and 5-year disease-free survival rates were 66.9%, 39.3%, and 29.8%. Risk factors of multivariate analysis of recurrence were GOT (>40 IU/L), alpha FP (>20 ng/dl), Child classification (B and C), tumor number (> or =2), tumor size (>5 cm), and extent of resection (major hepatectomy). Prognostic factors of multivariate analysis of overall survival rate were GOT, tumor number, and extent of resection. CONCLUSION: Although the recurrence rate is still high, identifying an individual patient who is at risk of tumor recurrence (GOT>40 IU/L, alpha FP>20 ng/dl, Child B and C, tumor number> or =2, tumor size >5 cm, and major hepatectomy) is helpful to estimate disease-free survival.

A Rapid Radicle Assay for Prescreening Antagonistic Bacteria Against Phytophthora capsici on Pepper

A rapid radicle assay for prescreening antagonistic bacteria to Phytophthora capsici, causal agent of Phytophthora blight of pepper was developed. Sixty-four bacterial strains with in vitro antifungal activity selected out of 1,400 strains isolated from soils of Ansung, Chunan, Koyang, and Paju, Korea in 1998 were used for development of the bioassay. Uniformly germinated pepper seeds dipped in bacterial cells for 3 hours were placed near the edges of growing mycelia of P. capsici on water agar containing 0.02% glucose. Five-week-old pepper plants (cv. Nockwang) were inoculated to compare with results of the radicle assay developed in this study. For plant inoculation, pepper seeds were sown in potting mixtures incorporated with the bacterial strains, then transplanted into steam-sterilized soils 3 weeks later. Plants were hole-inoculated with zoospores of P. capsici 2 weeks after transplanting. Disease incidence and severity were determined in radicle and plant assessments, respectively. In radicle assay, six strains, GK-B15, GK-B25, OA-B26, OA-B36, PK-B09, and VK-B14 consistently showed the significant (P=0.05) disease reduction against radicle infection by the fungus, four of which also did in plant assessments. Strains OA-B36 and GK-B15 consistently reduced the fungal infection in both the radicle assay and the plant assessment. Therefore, prescreening strains using the radicle assay developed in this study followed by plant assay could reduce time and labor, and improved the possibility of selecting antagonistic bacteria for control of Phytophthora blight of peppers.

Screening for In Vitro Antifungal Activity of Soil Bacteria Against Plant Pathogens

Antifungal bacteria for biological control of plant diseases or production of novel antibiotics to plant pathogens were isolated in 1997 from various soils of Ansung, Chunan, Koyang, and Paju in Korea. Sixty-four bacterial strains pre-screened from approximately 1,400 strains were tested on V-8 juice agar against eight plant pathogenic fungi using in vitro bioassay technique for inhibition of mycelial growth. Test pathogens were Alternaria mali, Colletotrichum gloeosporioides, C. orbiculare, Fusarium oxysporum f. sp. cucumerinum, F. oxysporum f. sp. lycopersici, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. A wide range of antifungal activity of bacterial strains was found against the pathogenic fungi, and strain RC-B77 showed the best antifungal activity. Correlation analysis between inhibition of each fungus and mean inhibition of all eight fungi by 64 bacterial strains revealed that C. gloeosporioides would be best appropriate for detecting bacterial strains producing antibiotics with potential as biocontrol agents for plant pathogens.