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Biomedical subjects

C W Kim

Publications and source records attributed to C W Kim.

At least 91 records · Page 5Linked to original sources

Eradication of Helicobacter pylori infection did not lead to cure of duodenal mucosa-associated lymphoid tissue lymphoma.

Duodenal mucosa-associated lymphoid tissue (MALT) lymphoma is very rare, and little is known about its clinical course or association with Helicobacter pylori infection. This report describes the case of a 76-year-old man with a polypoid mass in the duodenal bulb, diagnosed as low-grade MALT lymphoma. H. pylori infection in the duodenal mucosa was confirmed by histology with silver stain. Endoscopic examination showed that the gross lesion regressed after the eradication of H. pylori despite its histopathologic persistence. Ten months later, however, cervical and intraperitoneal lymphadenopathy and bone marrow involvement was observed, and the pathologic diagnosis of the cervical lymph node was identical with that of the duodenal lesion.

Aged↗

A case of edematous striae distensae in lupus nephritis.

A 17-year-old girl with systemic lupus erythematosus presented with painful edematous abdominal striae. She had been treated with systemic steroid for the systemic lupus erythematosus. At the time of presentation, she had abruptly gained 10 kg due to combined lupus nephritis. The histopathologic finding of the edematous striae distensae included dermal edema with separation of collagen fibers and small fragmented elastic fibers. Edematous striae distensae are uncommon but can develop from the combined effects of glucocorticoid and generalized edema.

Abdomen↗

Amino acid sequence analysis of bitter peptides from a soybean proglycinin subunit synthesized in Escherichia coli.

The cDNA encoding A1aB1b proglycinin was expressed in E. coli, for the efficient isolation of a single peptide responsible for the bitterness. The 55-kD proglycinin was highly purified, hydrolyzed, and further purified through a series of chromatographic steps to yield fractions with the major bitter peptides. The most bitter-tasting fractions contained peptides with average molecular weights lower than 1,700 Da. An analysis of the amino acid sequences indicated that many small bitter peptides (< 1,000 Da) are composed of uncharged polar amino acids as well as hydrophobic amino acids, with a charged residue often being present at either end. This suggests the involvement of a certain structural requirement in taste perception.

Amino Acid Sequence↗

Heel pain in children. Diagnosis and treatment.

Heel pain in children is common, and its evaluation is challenging. Medical history and physical examination may be unrevealing owing to children's limited communication skills. Often, advanced laboratory and imaging studies are required to make an accurate diagnosis. The most common causes of heel pain in children are apophysitis, enthesopathy, and overuse syndromes such as tendinitis. Juvenile rheumatoid arthritis is relatively uncommon. In very active children, occult fractures must also be evaluated. Pain unrelated to activity may indicate tumors, infection, or congenital problems. In general, heel pain in children is treated nonoperatively. For fractures in particular, children are less likely than adults to receive surgical treatment.

Child↗

Up-regulation of the expression of major histocompatibility complex class I antigens by plasmid DNA transfection in non-hematopoietic cells.

The effect of DNA on the surface expression of major histocompatibility (MHC) class I antigens was examined in non-hematopoietic tumor cell lines. Transfection with plasmid DNA via liposome or electroporation significantly increased the surface expression of MHC class I molecules in a transient manner. Northern blot analysis showed that levels of MHC class I mRNA were increased by DNA transfection, probably via transcriptional activation. In contrast, the expression of the MHC class II and beta-actin genes was not affected, suggesting that the up-regulation of MHC class I expression by plasmid DNA works in a gene-specific manner.

Actins↗

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↗

REAL classification of malignant lymphomas in the Republic of Korea: incidence of recently recognized entities and changes in clinicopathologic features. Hematolymphoreticular Study Group of the Korean Society of Pathologists. Revised European-American lymphoma.

BACKGROUND: The clinicopathologic characteristics of malignant lymphomas vary according to geography. The aim of this study was to determine the clinical characteristics of malignant lymphomas and the relative frequency in the Republic of Korea of lymphomas belonging to the newly described REAL (revised European-American lymphoma) classification categories. METHODS: The Hematolymphoreticular Study Group of the Korean Society of Pathologists conducted a consensus-based morphologic review of a nationwide collection of 1548 malignant lymphomas, including Hodgkin's disease (HD), diagnosed at 23 institutes over a recent 2-year period. Slides stained with hematoxylin and eosin or other immunohistochemical stains were reviewed. All cases were classified according to the histologic criteria proposed by the International Lymphoma Study Group. Clinical data, including age, gender, and site of disease involvement, were reviewed. RESULTS: The Republic of Korea had lower rates of HD and follicle center lymphoma and higher rates of extranodal lymphoma, diffuse large B-cell lymphoma, and angiocentric lymphoma compared with Western countries. The most frequent subtypes of non-Hodgkin's lymphoma (NHL) were diffuse large B-cell lymphoma, extranodal marginal zone B-cell lymphoma, peripheral T-cell lymphoma, unspecified type, and angiocentric lymphoma, in decreasing order. Compared with a previous nationwide study, the rates for follicular lymphoma and NHL involving the stomach, orbit, and central nervous system were increased. The rate of T-cell NHL in the current study was much lower than that reported in a previous study for the Republic of Korea and was also lower than that reported for other Far East countries. For HD, the relative frequency of nodular sclerosis subtype was higher compared with that in the previous study, and lymphocyte predominance and lymphocyte depletion were lower. CONCLUSIONS: The occurrence rates for various subtypes of malignant lymphoma in the Republic of Korea are distinct from those in Western countries and similar in many ways to those in other countries in the Far East. Compared with other Far East countries, the Republic of Korea has a higher rate of extranodal lymphoma, rare adult T-cell lymphoma, and a relatively low rate of T-cell lymphomas. It appears that over time there have been changes in the relative rates for follicular lymphoma, subtypes of Hodgkin's disease, and gastric and orbital lymphoma. The authors attribute these changes primarily to refined criteria for diagnosing new clinicopathologic entities.

Adolescent↗

In vivo radioprotective effects of oltipraz in gamma-irradiated mice.

Previous studies in this laboratory have shown that oltipraz (Olt), a chemopreventive agent, enhances radiation(Rad)-inducible glutathione S-transferase (GST) and microsomal epoxide hydrolase (mEH) expression in the liver. The present study was designed to investigate the in vivo radioprotective effect of Olt in ICR mice exposed to a lethal dose of Rad. The 30-day survival rate of mice irradiated at the dose of 8 Gy was substantially increased to 91% by Olt pretreatment (100 mg/kg/day for 2 days), compared with 48% in animals irradiated alone. Light microscopic examinations revealed that exposure of mice to 8 Gy of gamma-ray Rad resulted in hepatocyte degeneration in the surviving animals from Day 1 through Day 22 after irradiation with certain degrees of necrosis observed at early times, whereas Olt treatment provided protection of the liver against irradiation with no hepatic necrosis noted. Mice irradiated at the dose of 8 Gy exhibited time-related decreases in the white blood cell (WBC), red blood cell (RBC), and platelet counts with maximal reduction noted at Day 10. Animals irradiated with Olt treatment showed no difference in peripheral blood cell counts or in the ratio of myeloid to erythroid bone marrow cells, compared with those irradiated alone. Northern RNA blot analysis showed that treatment of mice with Olt at the dose of 100 mg/kg in combination with 8 Gy irradiation resulted in 12-fold increases in hepatic mEH and mGSTA3 mRNA levels at 24-hr post-treatment, whereas mGSTP1 mRNA levels were not altered. The mRNA levels for mEH and mGSTA3 were elevated after exposure of animals to both Olt and 8 Gy-gamma ray to a greater extent than after irradiation alone. The enhanced survival rate (91%) in 8 Gy-irradiated animals after treatment with Olt (100 mg/kg/day for 2 days) was completely reversed by concomitant pretreatment with dexamethasone (Dexa) (0.1 and 1 mg/kg/day for 2 days), a known inhibitor of mEH and GST expression, resulting in a 42% and 28% survival rate, respectively. Mice irradiated after dexamethasone treatment at a dose of 1 mg/kg showed a reduced mean survival time compared with those treated with 0.1 mg/kg of dexamethasone (9 vs 14 days). The current study demonstrates that Olt is effective in increasing the survival rate of mice against ionizing Rad and that protective effects of Olt associated with enhanced expression of mEH and GST genes may represent its radioprotective efficacy.

Animals↗

Multiple phosphorylation of chicken protein tyrosine phosphatase 1 and human protein tyrosine phosphatase 1B by casein kinase II and p60c-src in vitro.

We have cloned a soluble chicken protein tyrosine phosphatase, named CPTP1, from the cDNA library of chicken intestine. The CPTP1 showed 92% sequence identity to the corresponding 321 amino acid residues of human PTP1B (HPTP1B). CPTP1 lacked 13 amino acids of the N-terminal region compared with HPTP1B, while the C-terminal 48 amino acid sequence of this protein was distinct from those of other PTPs. In vitro phosphorylation and phosphoamino acid analysis showed that both CPTP1 and HPTP1B were phosphorylated on serine and threonine residues near their N-terminus by casein kinase II (CKII). Furthermore, phosphorylation of CPTP1 by CKII resulted in an inhibition of its phosphatase activity in vitro. Interestingly, both CPTP1 and HPTP1B were also tyrosine-phosphorylated near their N-terminus by p60c-src. When we examined the vanadate effect, in the absence of vanadate, the tyrosine-phosphorylated CPTP1 by p60c-src was autodephosphorylated by its own phosphatase activity. These results suggest that both CPTP1 and HPTP1B might play an important role in CKII- and p60c-src-induced signal transduction cascades.

Amino Acid Sequence↗

Sequence variation of EBNA2 of Epstein-Barr virus isolates from Korea.

To reveal sequence variations in the Epstein-Barr virus nuclear antigen 2 (EBNA2) genes of Epstein-Barr virus (EBV) strains circulating in the Korean population, the EBNA2 divergent region was amplified and sequenced from 13 EBV-1 isolates, 2 EBNA2 type 1 intertypic EBV isolates, and two EBV-2 isolates, all derived from Korean cancer patients. Comparative sequence analysis revealed that type 1 and type 2 EBNA2 divergent regions of Korean EBV isolates were almost identical to the respective regions of the B95-8 EBV-1 and AG876 EBV-2 strains. Two of the nucleotide changes found in the type 1 divergent regions of all Korean isolates, G-to-T and C-to-A at B95-8 EBV positions 48,991 and 48,998, respectively, are also present in all EBV-1 strains of non-Asian origins, indicating that these two sites might be mutational hot sites. Besides these two mutations, EBV-1 strains from Papua New Guinea or European Caucasians and Africa show unique patterns of identical sequence variations from B95-8, which were not found in type 1 isolates from Korea, suggesting that Korean type 1 are evolving as a lineage distinct from isolates from Papua New Guinea or European Caucasian and Africa.

Africa↗

Alteration of signal-transducing molecules in tumor-infiltrating lymphocytes and peripheral blood T lymphocytes from human colorectal carcinoma patients.

Tumor development or growth is accompanied by impaired immune responses, such as a poor proliferative response or down-regulated cytolytic T lymphocyte activity. Although recent reports have suggested that modification of the signal-transducing molecule is responsible for impaired immune responses in tumor-bearing hosts, the causes of defective immune function are not yet completely understood. Furthermore, the clinical significance of the findings is not yet clear. In this study, we investigated the alteration of several signal-transducing molecules in peripheral blood T lymphocytes (T-PBL) as well as in tumor-infiltrating lymphocytes (TIL) from human colorectal carcinoma patients and their relationship with the impaired host immune responses. A greater reduction in CD3zeta chain level was observed in TIL than in T-PBL from tumor-bearing hosts. CD3zeta chain reduction in T-PBL correlated with the clinicopathological stage of a tumor, especially with the status of lymph node metastasis. The levels of p56lck and p59fyn protein tyrosine kinase in T-PBL were also compared between tumor-bearing hosts and normal healthy volunteers. In T-PBL from tumor-bearing hosts, expression of protein tyrosine kinase p59fyn was significantly lower than that of p56lck. However, the level of CD3zeta chain expression did not correlate with T lymphocyte functions such as T lymphocyte proliferative response or allogeneic target cell lysis.

CD3 Complex↗

Thymic epithelial tumor progression in an SV40T transgenic mouse model. Cortical thymoma-thymic carcinoma sequence.

There have been several reports that thymoma in human is a progressive disease, and that thymoma and thymic carcinoma form a continuum. We established a stable line of SV40T transgenic mice, which consistently produced thymic epithelial tumours progressing to thymic carcinoma within a predictable time span. Using this animal model and a morphological approach, thymic epithelial tumour progression was studied with reference to sequential changes at different time points in animals aged from 3 to 32 weeks. At all ages, SV40T was expressed in the nuclei of thymic epithelial cells; in these transgenic mice we observed the entire spectrum from cortical type thymoma to thymic carcinoma. Thymic size tended to increase with ageing in SV40T TG mice. While younger mice had predominantly cortical (organoid) or cortical thymoma, older mice had well-differentiated thymic carcinoma (WDTC) or poorly differentiated thymic carcinoma. When SV40T TG mice (248 line) reached a certain age, carcinoma of the thymus was present in all of them. Cortical-type thymoma became malignant within a predictable time span, suggesting a cortical thymoma-carcinoma sequence. When the mice were 9 weeks of age, the thymuses formed gross masses compatible with cortical thymoma. At 14 weeks of age, WDTC appeared against the background of cortical thymoma. Poorly differentiated thymic carcinoma was found after 15 weeks and affected all animals over 23 weeks of age. Most thymic carcinomas coexisted in varying proportions with cortical-type thymoma. Medullary thymomas did not develop in the mice, and no transition from medullary-type thymomas to thymic carcinomas was observed. In this SV40T transgenic mouse model, thymic carcinoma is clearly preceded by cortical-type thymoma. These transgenic mice may provide an interesting model for the progression from cortical thymoma to WDTC and/or high-grade carcinoma.

Aging↗

The role of platelet-activating factor in regional myocardial ischemia-reperfusion injury.

BACKGROUND: This swine model was designed to elucidate the role of platelet-activating factor in regional myocardial ischemia-reperfusion injury. METHODS: In groups 1 and 2 (n = 12 each), the left anterior descending coronary artery was ligated for 60 minutes to induce regional myocardial ischemia followed by 6 hours of reperfusion. Group 1 received the platelet-activating factor antagonist TCV-309 before ischemia, whereas group 2 did not. Group 3 (n = 3) had a sham operation. RESULTS: Animals in group 2 exhibited significant (p < 0.05) hemodynamic instability and myocardial depression during the reperfusion period. Despite preventive measures, 7 of the 12 animals experienced severe dysrhythmias in the form of atrial and ventricular fibrillation leading to cardiac arrest. In contrast, animals in group 1 in whom the effects of platelet-activating factor were blocked by the specific platelet-activating factor receptor antagonist TCV-309 were hemodynamically stable and had significantly (p < 0.05) better myocardial function. This significant difference in global myocardial function between the groups was observed in the presence of similar morphologic findings and regional myocardial function. CONCLUSIONS: These results suggest that platelet-activating factor has a definite influence on global myocardial dysfunction associated with regional myocardial ischemia-reperfusion injury.

Animals↗

Expression of Bfl-1 in normal and tumor tissues: Bfl-1 overexpression in cancer is attributable to its preferential expression in infiltrating inflammatory cells.

Bfl-1, a member of the Bcl-2 gene family, blocks p53-mediated apoptosis and has oncogenic transforming activity. In normal tissues, the transcript of Bfl-1 is expressed abundantly in bone marrow and at a low level in several other tissues. In previous experiments, elevated expression of Bfl-1 was observed by Northern analysis of stomach cancer samples. To study the role of Bfl-1 in normal cell development and in tumorigenesis, we have analyzed the expression of Bfl-1 in normal and tumor tissues by the in situ hybridization technique. The Bfl-1 transcript was detected in the white pulp of the spleen and in the germinal center of lymphatic tissues. In tumor tissues, its expression was preferentially detected in infiltrating inflammatory cells rather than in cancer cells, suggesting that Bfl-1 is not involved in tumorigenesis.

Colonic Neoplasms↗