Thirty turtles (15 Clemys mutica and 15 Geoclemys reevesii) which were inoculated with human sera those were positive for hepatitis B surface antigen (HBsAg) and hepatitis B "e" antigen (HBeAg) were found to be infected with hepatitis B virus (HBV). The levels of HBV infection markers, such as HBsAg and antibody to HBsAg (anti-HBsAg), were retinely monitored in the turtles' serum for 46 weeks. Within two weeks of the inoculation, 42% of the turtles tested were positive for HBsAg, and their reciprocal titers as measured by reverse passive hemagglutination (RPHA) and enzyme linked immunoabsorbance assay (ELISA) ranged from 16 to 96. Within 20 weeks, the remaining turtles tested HBsAg positive, as confirmed by ELISA. At 20 weeks, all but one of the turtles exhibited changes in HBV blood marker from HBsAg to anti-HBs; the one exception was positive for both HBsAg and anti-HBs. At the 47th week, 7 animals were killed and their organs were examined for HBV infected cells utilizing an immunofluorescent technique. Numerous fluorescent cells which reacted with human anti-HBs nad anti-HBc were observed in the following organs: pancreas, liver, kidney, and brain. Histopathologically, edematous changes in hepatocytes and minor cellular infiltration attributed to an inflammatory response were noted. Liver and kidney cells from the infected animals were cultured, and HBV antigen positive cells for HBsAg and HBcAg were detected in the cultures. Throughout the experiment, HBsAg was detected in the supernatant by ELISA. Virus particles which were indistinguishable from Dane particles were seen in the cytoplasmic vacuoles of the cultured cells by electron microscopy. Finally, the presence of HBV DNA was established by molecular hybridization techniques in the culture supernatants of kidney cells from the infected turtles.
Animal ; Hepatitis B/microbiology/transmission/*veterinary ; Hepatitis B Antibodies/isolation and purification ; Hepatitis B Core Antigens/isolation and purification ; Hepatitis B Surface Antigens/isolation and purification ; Human ; Kidney/microbiology ; Liver/microbiology/pathology ; Turtles/*microbiology

No abstract available.
Colorectal Neoplasms* ; Fluorouracil* ; Leucovorin*

No abstract available.
Cisplatin* ; Humans ; Nausea* ; Vomiting*

Invasive aspergillosis is an infection that occurs in immunocompromised patients. Its prevalence was increased in the last decade with progression of antineoplastic chemotherapy and immunosuppressive therapy after transplantation. Because it carries a high mortality and morbidity, early diagnosis and aggressive treatment are critical for successful management. In many patients, invasive aspergillosis remains confined to the lung although direct extension to pleural cavity or pericardium has been reported. However great vessel involvement is rare. Therefore we report a case of invasive aspergillosis involving right subclavian artery and chest wall in a patient after chemotherapy for acute lympoblastic leukemia.
Aspergillosis ; Drug Therapy ; Early Diagnosis ; Humans ; Immunocompromised Host ; Invasive Pulmonary Aspergillosis* ; Leukemia ; Lung ; Mortality ; Pericardium ; Pleural Cavity ; Prevalence ; Subclavian Artery* ; Thoracic Wall* ; Thorax*

PURPOSE: Hepatocellular carcinoma (HCC) is one of the most common malignancy with high mortality in Korea. A new therapeutic modality such as gene therapy is necessary to improve the prognosis of hepatoma patients. Therefore we investigated the preclinical significance of Herpes simplex virus - thymidine kinase/ganciclovir (HSV-tk/GCV) gene therapy model using the retroviral vector for HCC cell lines. MATERIALS AND METHODS: LNC/HSV-tk retroviral vector and PA317/LNC/HSV-tk pro- ducer cell line were constructed. HSV-tk transduced HCC cells using the LNC/HSV-tk retrovirus were selected by the G418 containing media. In vitro GCV sensitivity test of the HCC cells was performed by MTT assay. To evaluate in vivo GCV sensitivity, GCV was intraperitoneally injected after subcutaneous administration of HCC cells into each flank of the nude mouse. RESULTS: HSV-tk gene transduction and expression in HCC cells were confirmed by RT-PCR. HSV-tk transduced HCC cell lines (SK-Hepl/HSV-tk and Hep-3B/HSV-tk) showed the marked GCV sensitivity comparing with the parental cell lines (SK-Hepl and Hep-3B) by MTT assay (p<0.001). The MTT test revealed that SK-Hepl/HSV-tk cells were more sensitive to GCV compare with that of Hep-3B/H5V-tk cells, and the parent cell line showed minimal growth suppression by the GCV treatment. In 12 nude mice received tumor cell mixtures of Hep-3B and Hep-3B/HSV-tk cells which contained more than 50% of HSV-tk transduced cells, the tumor was not developed in ll mice by the intraperitoneal administration of GCV. The tumors developed in 1 of 6 mice and 5 of 6 mice when mixtures contained 30% and 10% of HSV-tk transduced cells, respectively. Five mice out of 6 mice received inoculum containing the mixtures of 70% and 50% of HSV-tk transduced cells into each flank survived more than 6 month after HSV-tk/GCV treatment. Conelusion: HSV-tk gene transduced HCC cells showed the enhanced sensitivity to GCV. In nude mice HSV-tk/GCV strategy for HCC seemed to be more effective when tumor cell inoculum contained more than 30% of HSV-tk transduced HCC cells.
Animals ; Carcinoma, Hepatocellular* ; Cell Line* ; Ganciclovir* ; Genetic Therapy ; Herpes Simplex* ; Humans ; Korea ; Mice ; Mice, Nude ; Mortality ; Parents ; Prognosis ; Retroviridae* ; Simplexvirus* ; Thymidine Kinase* ; Thymidine* ; Zidovudine

No abstract available.
Picibanil* ; Pleural Effusion, Malignant*

The intensive use of chemotherapeutic agents for the treatment of cancer has resulted in the cure or improved survival of many patients. But unfortunately, many cancers including human hepatocellular carcinoma (HCC) don't respond to chemotherapy. One of the major mechanisms for the drug resistance in the HCC is an elevated MDR1 RNA expression which makes cells become multidrug resistant. To overcome the multidrug resistance (MDR) phenotype, a high dose of verapamil is required both clinically and experimentally. Accordingly we have examined the MDR modulating effects with combinations of tamoxifen, cyclosporin A, and verapamil in vitro with the physiologically achievable concentrations of each agent, i.e., 2.0 microM/L for tamoxifen, 1.6 microM/L for cyclosporin A, and 2.5 microM/L for verapamil respectively in HCC lines. As expected, verapamil alone with the physiologically achievable concentration at which we tested didn't enhance the doxorubicin cytotoxicity in the HCC lines. Furthermore, any verapamil combination with cyclosporin A or tamoxifen was not effective in overcoming the doxorubicin resistance in the high MDR1 expressor (Hep-G2) line. However tamoxifen reduced the IC50 of doxorubicin by a factor of 1.9 in the low MDR1 expressor (SK-Hep1) and 1.1 in the high MDR1 expressor line (p< 10(-5) respectively). Of interest, combinations of tamoxifen and cyclosporin A showed a significant reduction in the IC50 of doxorubicin in both HCC lines. The IC50 of doxorubicin was reduced by a factor of 3.9 and 1.3, i.e., from 0.023943 micrograms/ml to 0.006157 micrograms/ml (p< 10(-5)) in the SK-Hep1 cell line, and 0.068819 micrograms/ml to 0.052442 micrograms/ml (p< 10(-5)) in Hep-G2 respectively when tamoxifen and cyclosporin A were administered together. Both the estrogen and progesterone receptors in the SK-Hep1 and Hep-G2 lines were less than 0.01 fmol/mg of cytosol protein, respectively. It is therefore suggested that the reversal of doxorubicin resistance is unrelated to their anti-estrogenic activity in the HCC lines. Three modulator combinations of tamoxifen, cyclosporin A, and verapamil were not more effective than the combination of tamoxifen and cyclosporin A on the sensitivity to doxorubicin. MDR modulators of tamoxifen, cyclosporin A, and verapamil didn't reduce the IC50 of cisplatin to the clinically achievable concentration range in HCC lines. In summary, the combination of tamoxifen and cyclosporin A at the concentrations normally seen after clinical administration of these modulators showed significant synergism on the sensitivity to doxorubicin in both low and high MDR1 expressor HCC lines. These data indicate the need for in vivo trials.
Antineoplastic Agents/*pharmacology ; Carcinoma, Hepatocellular/*physiopathology ; Cyclosporine/*pharmacology ; Drug Resistance ; Human ; Liver Neoplasms/*physiopathology ; Support, Non-U.S. Gov't ; Tamoxifen/*pharmacology ; Tumor Cells, Cultured/drug effects ; Verapamil/*pharmacology

PURPOSE: To overcome the limitations of cancer gene therapy using replication-incom- petent adenovirus, we generated E1B 55 kD-deleted adenovirus (YKL-1) by polymerase chain reaction (PCR) and homologous recombination. We then investigated tumor-specific virus replication and cytotoxicity of YKL-1 in vitro and in vivo. MATERIALS AND METHODS: YKL-1 was constructed by reintroducting E1A and E1B 19 kD into pTG-CMV El/E3-deficient adenoviral vector and inducing homologous recombination in E. coli. The recombinant vector pYKL-1 was transfected into 293 cells to generate YKL-1. The properties of newly constructed YKL-1 was defined by PCR and immuno- blotting analysis. Virus replication was examined by infecting human normal and cancer cells on 6-wells at multiplicity of infection (MOI) of 10 for 3 days. Virus was then recovered and titered. Cytopathic effect was analyzed by infecting human normal and cancer cells on 24-wells at MOIs of 10, 1 or 0.1 for 7 to 10 days and staining them with crystal violet solution. Inhibition of tumor growth was examined in human cancer cell xenografts in nu/nu mice by intratumoral injection of YKL-l. RESULTS: PCR and immunoblotting analysis confirmed that YKL-1 contained E1A and E1B 19 kD but not E1B 55 kD. In human normal cells, virus replication and subsequent cytopathic effect of E1B 55 kD-deleted adenovirus YKL-1 was markedly attenuated by larger than 2 to 3 log in magnitude, compared to that of wild-type ad-XJ. In contrast, YKL-1 was capable of replicating and inducing cytotoxicity i.n most human cancer cells. C33A and Hep3B containing p53 mutation were much more sensitive, whereas HeLa and H460 with wild type p53 were relatively resistant to YKL-1. Finally, the tumor growth was dramatically retarded by intratumoral injection of YKL-1 in C33A cervical cancer xenograft and the histology showed significant necrosis by intratumoral injection of YKL-1. CONCLUSION: The results here demonstrated the ability of preferential virus replication and cytotoxicity of ElB 55 kD-deleted adenovirus YKL-1 in human cancer cells. Therefore, these indicated a promising potential of YKL-1 as an antitumoral virus agent and a selective replication-competent virus vector.
Adenoviridae* ; Animals ; Genes, Neoplasm ; Genetic Therapy ; Gentian Violet ; Heterografts ; Homologous Recombination ; Humans ; Immunoblotting ; Mice ; Necrosis ; Polymerase Chain Reaction ; Uterine Cervical Neoplasms ; Virus Replication*

PURPOSE: Gastric cancer is the most common malignancy in Korea. Although treatment such as surgery, chemotherapy, and immunotherapy has greatly improved, the mortality rate of gastic cancer is still high, A new therapeutic trial is necessary to improve the cure rate of gastric cancer. Therefore we investigated the pre-clinical significance of HSV-tk gene therapy using retroviral vector for gastric cancer cell lines. MATERIALS AND METHODS: LNC/HSV-tk retroviral vector and PA317/LNC/HSV-tk producer cell line were constructed. HSV-tk gene transduction and expression were detected by PCR. An in vitro ganciclovir(GCV) sensitivity test was performed by MTT assay. To evaluate in vivo GCV sensitivity, GCV was intraperitoneally injected after tumor formation in the nude mice. Bystander effect was observed in vitro MTT assay using YCC- S-2 cell line and in vivo using N87 and YCC-S-2 cell lines. RESULTS: The in vitro GCV sensitivity test showed that the growth inhibition was 30~32% with 0.5 uM GCV and 52~77% with 500 uM GCV in the HSV-tk transduced cell line in comparison with 0- 5% with 0.5 and 500 uM GCV in the parent cell line. The in vivo GCV administration showed that the tumors induced by HSV-tk transduced N87 cell line and YCC-S-2 cell line decreased completely, while the tumors with the parent cell lines continued to grow in nude mice. We observed no tumor cells in tissue specimen of the tumor induced by the N87/HSV-tk cell line after. GCV administration. In vitro and in vivo bystander effects were observed in HSV-tk/GCV system due to the resultant cell death exceeding the proportion of HSV-tk transduced cells in the mixtures of HSV-tk transduced and parent cells. CONCLUSION: HSV-tk transduced gastric cancer cell lines showed sensitivity to GCV and a bystander effect was observed. These results suggested that HSV-tk/GCV system should be evaluated in the clinical settings.
Animals ; Bystander Effect ; Cell Death ; Cell Line* ; Drug Therapy ; Ganciclovir* ; Genetic Therapy ; Herpes Simplex* ; Humans ; Immunotherapy ; Korea ; Mice ; Mice, Nude ; Mortality ; Parents ; Polymerase Chain Reaction ; Stomach Neoplasms* ; Thymidine Kinase* ; Thymidine* ; Zidovudine

Our previous study revealed that mutations of the p53 gene were detected by cDNA sequencing in one of four (25%) primary gastric tumors and in five of six (83%) gastric cancer cell lines. It was of interest that all five cell lines established from metastatic lesions had p53 gene mutations, while the single cell line established from a primary tumor lacked an abnormality. Thus, the current study was initiated to determine the frequency of p53 mutations in 10 pairs of samples from primary gastric carcinomas and their lymph node metastases, in addition to morphologically normal gastric mucosa. In addition, we correlated the findings with other relevant molecular markers including the metastasis associated nm23-H1 gene and loss of heterozygosity (LOH) using multiple polymorphic markers for chromosome 17p and sequencing the entire open reading frame (ORF) of the p53 gene. Five of ten (50%) patients were constitutionally heterozygous for one or more 17p and/or p53 probes (pYNZ 22, BamHI RFLP; pMct35.1, Mspl RFLP; php53cl, Bg/II RFLP), while none had LOH at the 17p and/or p53. A Bg/II RFLP for analysis of possible nm23-H1 somatic allelic deletion revealed no LOH out of four informative cases. One paired sample demonstrated the substitution of valine for isoleucine at codon 41 (GTT to ATT) in both primary gastric tumor and metastasis. Another metastatic sample demonstrated the substitution of proline for threonine at codon 278 (CCT to C/ACT) in addition to a non-mutated codon, while only the wild-type p53 sequence was present in the paired primary gastric tumor tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
Base Sequence ; Chromosome Deletion ; DNA, Complementary/chemistry ; *Genes, p53 ; Humans ; Molecular Sequence Data ; Mutation ; Neoplasm Metastasis/*genetics ; Polymorphism, Restriction Fragment Length ; RNA, Messenger/analysis ; Stomach Neoplasms/*genetics/pathology/secondary