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Biomedical subjects

E K Cho

Publications and source records attributed to E K Cho.

10 recordsLinked to original sources

Array-based comparative genomic hybridization and copy number variation in cancer research.

Array-based comparative genomic hybridization (aCGH) is a molecular cytogenetic technique used in detecting and mapping DNA copy number alterations. aCGH is able to interrogate the entire genome at a previously unattainable, high resolution and has directly led to the recent appreciation of a novel class of genomic variation: copy number variation (CNV) in mammalian genomes. All forms of DNA variation/polymorphism are important for studying the basis of phenotypic diversity among individuals. CNV research is still at its infancy, requiring careful collation and annotation of accumulating CNV data that will undoubtedly be useful for accurate interpretation of genomic imbalances identified during cancer research.

Animals↗

COMT genotype and effectiveness of entacapone in patients with fluctuating Parkinson's disease.

OBJECTIVE: To investigate the relationship between the catechol-O-methyltransferase (COMT) genotype and the therapeutic efficacy of entacapone. METHODS: The efficacy of 2 months of entacapone treatment in 65 patients with PD with end-of-dose deterioration was studied. The efficacy of entacapone was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) score, the daily levodopa dosage, and the patients' diary card. RESULTS: Thirty-six patients (55.4%) had a high-activity COMT gene (COMT(HH)), 22 (33.8%) had an intermediate-activity COMT gene (COMT(HL)), and 7 patients (10.8%) had a low-activity COMT gene (COMT(LL)). Two months of entacapone treatment resulted in a significant increase in "on" time, a reduction in "off" time, and a reduction in the total UPDRS score, but these results were independent of the COMT genotype of the patient. There was no significant difference in the frequency or severity of dyskinesias between the patients with different COMT genotypes. CONCLUSION: The COMT genotype seems to be a minor factor in judging the beneficial effects of entacapone administration.

Aged↗

Ontogeny of natural killer cells and T cells by analysis of BCR-ABL rearrangement from patients with chronic myelogenous leukaemia.

Chronic myelogenous leukaemia (CML) is a haematological malignant disorder characterized by the Philadelphia chromosome (Ph) and BCR-ABL gene rearrangement. This abnormal fusion gene can be considered to serve as a marker for the transformed cell clone in CML and is found in all cells arising from the same malignant precursor cell. It has been detected in CML cells of the myeloid, monocytic, erythroid and B-lymphocytic lineages. However, it is still arguable as to whether T lymphocytes or natural killer (NK) cells carry this marker. Answering this question would clarify the ontogenic relationship between NK cells and T cells. We examined 12 CML patients and studied the expression of BCR-ABL rearrangement by fluorescence in situ hybridization (FISH) in both NK cells and T cells sorted by flow cytometry. The purity of T cells was 95.6-99.8% and that of NK cells was 95.3-99.3% after sorting. Neither NK cells nor T cells showed any positive BCR-ABL signal with the exception of one patient who recovered from a lymphoid blastic crisis. We speculate that T cells and NK cells originate from BCR-ABL-negative stem cells.

Adult↗

Phase II clinical trial of SKI-2053R, a new platinum analog, in the treatment of patients with advanced gastric adenocarcinoma.

BACKGROUND: SKI-2053R (SK Chemicals, Kyungki-Do, South Korea) is a new platinum derivative with antitumor activity against various cell lines, including cisplatin-resistant tumor cell lines. Preclinical studies have suggested that it is less nephrotoxic than cisplatin. This study evaluated the efficacy and toxicity of SKI-2053R in the treatment of patients with advanced gastric adenocarcinoma. METHODS: Thirty-seven patients with advanced gastric adenocarcinoma that was unresectable or metastatic were treated. No prior chemotherapy or radiotherapy was allowed. Patients received SKI-2053R 360 mg/m(2) by 1-hour infusion on Day 1. After the first cycle, subsequent doses were adjusted according to the toxicity. Courses were repeated every 28 days. RESULTS: Thirty-five patients were evaluable for response and toxicity. Six patients achieved a major response (17%; 95% confidence interval, 8-33%); 2 were complete and 4 were partial responses. The median duration of response was 7.2 months, with a range of 1-20 months. Patients could tolerate the treatment without significant toxicity. No patients had Grade 3 or 4 toxicity. The most frequent toxicity was Grade 1 or 2 proteinuria (26% of cycles), but it was mild and transient. Leukopenia, thrombocytopenia, azotemia, nausea and vomiting, and neurotoxicity were not frequent. These low toxicity profiles indicated that the dose of SKI-2053R could be increased in future studies. CONCLUSIONS: SKI-2053R was active in the treatment of patients with gastric adenocarcinoma and had favorable toxicity profiles.

Adenocarcinoma↗

Locoregional response and increased natural killer activity after intratumoral injection of HLA-B7/beta2-microglobulin gene in patients with cancer.

The purpose of this study was to assess the therapeutic potential of injecting the gene for HLA-B7/beta2-microglobulin into the subcutaneous metastatic nodules of patients who are refractory to conventional treatments. The nine patients evaluated were divided into three groups and given escalating doses of DNA (20, 40, and 100 microg of the HLA-B7 plasmid DNA/lipid complex for each group) every 2 weeks. Biopsy specimens from the treated tumor nodules of all nine patients were positive for the presence of DNA and for HLA-B7 mRNA expression. Moreover, in six of the nine patients, immunohistology of tumor biopsy samples revealed the expression of recombinant HLA-B7 protein. Also, all nine patients showed an increase in NK activity in their circulating peripheral blood lymphocytes. In two lung cancer patients, one partial and one mixed response was observed after gene transfer. These responses were confined to the treated nodules and the untreated locoregional lymph nodes; the lung masses showed no regression. Remission durations were 14 and 6 weeks, respectively, and in a total of 35 cycles no significant toxicities were observed. Immunohistologic analysis revealed an increased infiltration of CD4+ T cells, macrophages, and NK cells after therapy. In two responding cases, direct intratumoral injection of an allogeneic class I gene could elicit an antitumor response in locoregional areas, possibly through the activation of NK cells.

Adult↗

In vitro immunohistochemical localization of S-phase cells by a monoclonal antibody to bromodeoxyuridine.

Bromodeoxyuridine, an analogue of thymidine, can be detected by means of monoclonal antibodies and utilized as a marker of the S-phase of the cell cycle. In vitro immunohistochemical application of the BrdU/anti-BrdU-MAb method permits a quantitative assessment of the proliferative activity of a tissue as well as the direct location of the actively replicating cells in histological sections. In this paper, a method for the detection of the labeling index of S-phase cells in normal and neoplastic tissues with in vitro BrdU labeling and standard immunohistochemical techniques using anti-BrdU-MAb and avidin-biotin peroxidase complex is described. We have employed this method in 47 human solid tumor samples, including squamous cell carcinomas of head and neck and cervix uteri, adenocarcinomas and malignant lymphomas, and also evaluated the possible application of the BrdU labeling index to estimate the cycling S-phase cells in neoplastic cell populations. In our data, the in vitro labeling index varied greatly in an individual case (3.56-29.2%) and from an area to an area within the same case. Squamous cell carcinomas of the head and neck showed higher LI than those of the cervix uteri. A case of metastatic carcinoma to the lung from ductal carcinoma of the breast had the highest LI (29.2%), in contrast to the low LI (3.6%) in the primary ductal carcinoma of breast.

Adenocarcinoma↗

Ramosetron for the prevention of cisplatin-induced acute emesis: a prospective randomized comparison with granisetron.

Control of nausea and vomiting is very important in determining patient compliance with cisplatin chemotherapy. A multicentre, randomized, single-blind study was conducted to compare the tolerability and efficacy of ramosetron with those of granisetron over 24 h following cisplatin administration to cancer patients. In eight study centres, a total of 194 adult patients were randomly assigned to receive either intravenous ramosetron 0.3 mg or intravenous granisetron 3.0 mg. The anti-emetic effect of ramosetron determined from the no-vomiting rate lasted longer, but there was no significant difference in the number of acute vomiting episodes or the severity of nausea between the two groups. In the tolerability evaluation, there were no statistically significant differences between the two groups, except for a higher incidence of dull headache in the granisetron group. Ramosetron and granisetron appear to have equivalent efficacy and tolerability profiles, but the effects of ramosetron on the prevention of acute vomiting in patients undergoing cisplatin chemotherapy were longer lasting.

Adult↗