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Biomedical subjects

C M Kim

Publications and source records attributed to C M Kim.

At least 19 recordsLinked to original sources
PubMed1992

cDNA cloning of MEV, a mutant protein that facilitates cellular uptake of mevalonate, and identification of the point mutation responsible for its gain of function.

We report the expression cloning of pMev, a cDNA that facilitates cellular uptake of mevalonate. pMev was isolated from the met-18b-2 clone of Chinese hamster ovary (CHO) cells, which were selected for growth in low concentrations of mevalonate when synthesis is blocked by compactin (Faust, J. R., and Krieger, M. (1987) J. Biol. Chem. 262, 1996-2004). pMev encodes a 494-residue protein, Mev, that is predicted to have 12 membrane-spanning regions, consistent with a membrane transporter. Surprisingly, levels of Mev mRNA and protein are similar in CHO and met-18b-2 cells. The Mev gene differs from the wild-type gene by a single base change that substitutes a cysteine for phenylalanine in the 10th membrane-spanning region. met-18b-2 cells are heterozygous for this dominant gain-of-function mutation. Transfection of a cDNA encoding pMev, but not the wild-type cDNA, elicited a marked increase in [3H]mevalonate uptake and incorporation into cellular lipids in stably and transiently transfected cells. The availability of pMev will facilitate studies of [3H]mevalonate incorporation into trace products, including p21ras and other prenylated proteins.

Amino Acid Sequence↗
PubMed1992

Modification of adriamycin-induced cytotoxicity by recombinant human interferon-gamma and/or verapamil in human stomach cancer cells.

Recombinant human-interferon-gamma (rH-IFN-gamma) and verapamil (VRP), either alone or in combination, were evaluated in MTT assay for their modification effects on adriamycin-induced cytotoxicity against MKN-45, human stomach adenocarcinoma cells. VRP as a single agent did not inhibit the survival of MKN-45 at doses of up to 5.0 micrograms/ml. The survival of MKN-45 was inhibited by rH-IFN-gamma dose-dependently and further inhibited by the addition of VRP. However, the maximum growth inhibition of MKN-45 in any combination treatment with rH-IFN-gamma and VRP was less than 50% except in the highest concentration combinations (% survival: 47.9% at 10(4) U/ml of rH-IFN-gamma and 3.0 micrograms/ml of VRP). Adriamycin caused a concentration-dependent cytotoxicity and its cytotoxicity was significantly enhanced by the addition of rH-IFN-gamma and further enhanced by the combined use of rH-IFN-gamma and VRP. The modification effects of rH-IFN-gamma and VRP on adriamycin-induced cytotoxicity were evaluated in terms of modification index (MI), demonstrating that rH-IFN-gamma significantly increased in adriamycin-induced cytotoxicity and that the combined use of rH-IFN-gamma and VRP enhanced the adriamycin-induced cytotoxicity to a greater extent than did rH-IFN-gamma alone: MI values at 10(2) U/ml and 10(3) U/ml of rH-IFN-gamma were 1.7 and 3.1, respectively; those at 1.5 micrograms/ml and 3.0 micrograms/ml of VRP in the presence of 10(3) U/ml of rH-IFN-gamma were 4.4 and 6.0, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1992

Malignant lymphomas of the nasal cavity and Waldeyer's ring--clinicopathologic and immunohistochemical study.

The clinicopathologic and immunohistochemical finding of 10 cases of nasal non-Hodgkin's lymphoma (NHL) and 23 cases of Waldeyer's ring NHL were studied. Immunohistochemically, nasal NHL expressed T-cell markers exclusively, whereas the NHL of Waldeyer's ring were of both T-cell (56.5%) and B-cell lineages (43.5%). Angioinvasiveness by tumor cells was exclusively noted in the T-lineage lymphomas. Epithelial hyperplasia, epitheliotropism by tumor cells, and extensive invasion of adjacent normal tissue were more prominent in T-cell lymphomas than in B-cell lymphomas. T-lineage lymphomas showed distant extranodal spread pattern involving the skin, soft tissue, stomach, spleen, and the liver, whereas B-lineage lymphomas tended to localize in the lymph nodes. The survival rate of Nasal NHL was similar to that of Waldeyer's ring NHL. Although not statistically significant because of small sample numbers, immunophenotype, histologic groups of monomorphic lymphoma, and stage had prognostic importance. In general, T-lineage lymphomas presented with a higher stage than B-lineage lymphomas (p < 0.05)-and overall survival was poor. Stage I disease showed a much more favorable prognosis than stage II disease. Monomorphic lymphomas had a shorter survival than polymorphic reticulosis (PR) or lymphomas with features of PR. This result in conjunction with the morphologic transition between them suggested that monomorphic lymphoma may represent the most advanced stage in the spectrum of PR, lymphoma with features of PR, and monomorphic lymphoma.

Adolescent↗
PubMed1992

The HIV tat gene transforms human keratinocytes.

Skin disorders are frequently seen in patients with the acquired immune deficiency syndrome (AIDS). Since many of these cutaneous manifestations are accompanied by an early onset of epidermal hyperplasia, the keratinocyte is a candidate for infection by the human immunodeficiency virus (HIV). We now report that the HIV tat gene, under the control of the viral long terminal repeat (LTR), can efficiently transform human keratinocytes in culture. Our finding suggests that this activity of the tat gene may be responsible for the epidermal hyperplasia that accompanies psoriasis and precedes the development of squamous cell and basal cell carcinomas in AIDS patients.

Animals↗
PubMed1991

Trauma studies.

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Ambulatory Care↗
PubMed1991

HBx gene of hepatitis B virus induces liver cancer in transgenic mice.

The exact role of hepatitis B virus in the development of liver cancer is not known. The recent identification of a viral regulatory gene HBx suggests a possible direct involvement of the virus whereby the HBx protein, acting as a transcriptional transactivator of viral genes, may alter host gene expression and lead to the development of hepatocellular carcinoma. We have tested this possibility of placing the entire HBx gene under its own regulatory elements directly into the germline of mice. Transgenic animals harbouring this viral gene succumbed to progressive histopathological changes specifically in the liver, beginning with multifocal areas of altered hepatocytes, followed by the appearance of benign adenomas, and proceeding to the development of malignant carcinomas. Male mice developed disease and died much earlier than females. This transgenic animal model appears ideal for defining the molecular events that follow the expression of the viral HBx gene and are responsible for the development of liver cancer.

Animals↗
PubMed1991

Inhibition of human hepatocellular carcinoma and hepatoblastoma cell lines by deferoxamine.

Inhibition of human hepatocellular carcinoma (PLC/PRF/5 and Hep3B) or hepatoblastoma (Hep G2) cell lines by inclusion of deferoxamine mesylate (desferrioxamine) (DFX) in the culture medium was evaluated. When PLC/PRF/5 cells were maintained for 7 days in 30 or 60 microM DFX, the cell number was decreased by 30-60%, little or no alpha-fetoprotein (AFP) was produced, and supernatant endpoint dilution titers of hepatitis B surface antigen (HBsAg) were reduced 1-2 logs. PLC/PRF/5 cells maintained for 7 days without DFX (simultaneous controls) grew to confluence, produced AFP that reached 10-60 ng/ml in the supernate, and the HBsAg titer remained constant or increased 1 log. Similar effects were observed in Hep3B and Hep G2 cells maintained in DFX (except that Hep G2 cells do not produce HBsAg), compared to simultaneous control cells grown in the absence of DFX. The growth of a human embryonic lung fibroblast cell line (Wl 38) was not significantly inhibited by DFX, although it grew at a slower rate than simultaneous control cells grown without DFX. Subsequent growth in FeSO4 of PLC/PRF/5, Hep3B, and Hep G2 cells that previously had been maintained in DFX did not reverse the effects of DFX. PLC/PRF/5 cells were also inhibited when maintained in medium containing equimolar concentrations of DFX and FeCl3 and in medium containing equimolar concentrations of DFX and FeSO4. PLC/PRF/5 cells were not inhibited by maintenance in up to 60 microM of another chelating agent that has a similar affinity for iron, calcium disodium versenate (EDTA). These studies show that DFX inhibits the growth of human hepatocellular carcinoma and hepatoblastoma cell lines regardless of the presence (PLC/PRF/5, Hep3B) or absence (Hep G2) of integrated hepatitis B virus DNA. The findings also suggest that the inhibition may have been due to mechanisms other than iron chelation.

Carcinoma, Hepatocellular↗
PubMed1991

Differential depression of lymphocyte subsets according to stage in stomach cancer.

Lymphocyte surface markers were determined in the peripheral blood lymphocytes (PBL) in 31 stomach cancer patients (15 males and 16 females) and 47 controls (20 males and 27 females) using an indirect immunofluorescence technique. The monoclonal antibodies used were Leu 2a (CD8, suppressor/cytotoxic T cells), Leu 3a (CD4, inducer/helper T cells), Leu 4 (CD3, pan T reagent), Leu 11 (CD16, natural killer cells) and Leu 12 (CD19, B cells). The numbers of PBL, CD3+, CD4+, CD8+, CD16+ and CD19+ cells significantly decreased and the CD4:CD8 value increased in patients with stomach cancer compared to those in healthy volunteers. In stage I, PBL, none of the PBL subsets nor the CD4:CD8 value were significantly different from those of the controls. In stage II, the numbers of PBL, CD3+, CD4+ and CD8+ cells decreased. In stage III, the CD19+ cells decreased in addition to the decreased subsets in stage II. In stage IV, PBL and all subsets measured decreased. The CD4:CD8 value showed significant increases in stages II, III and IV, because the CD8+ cells decreased to a greater extent than did the CD4+ cells. Changes in the subsets were analyzed with regard to age, sex, performance status and smoking history, no significant relation being observed between these factors and lymphocyte subsets. From the present study, we have demonstrated that lymphocyte subsets were differentially depressed in the order of T cells, B cells and natural killer cells, with progression of the stage of disease.

Adult↗
PubMed1991

Evaluation of hybridization characteristics of a cloned pRF106 probe for Listeria monocytogenes detection and development of a nonisotopic colony hybridization assay.

An internal fragment (pRF106 fragment, ca. 500 bp) of a gene (msp) coding for a 60-kDa protein of Listeria monocytogenes serotype 1/2a was used to develop a screening method to discriminate between L. monocytogenes and avirulent Listeria spp. on primary isolation plates. The L. monocytogenes-derived probe fragment of pRF106 hybridized to a 13-kb fragment of L. monocytogenes and a 3-kb fragment of one cheese isolate strain of Listeria seeligeri under stringent hybridization conditions (mean thermal denaturation temperature [Tm]-5 degrees C). The probe also hybridized to a 6-kb fragment of Listeria innocua, Listeria ivanovii, and L. seeligeri under less stringent hybridization conditions (Tm-17 degrees C). The pRF106 fragment was labeled with digoxigenin-11-dUTP and used to develop a colony hybridization assay. Colonies from lithium chloride-phenylethanol-moxalactam agar were blotted onto nylon membranes. The cells were pretreated with microwaves before lysis with sodium hydroxide. DNA-DNA hybridization and posthybridization washing were done at high stringency (Tm-7 degrees C). The nonisotopic colony hybridization procedure was specific for L. monocytogenes when evaluated against pure cultures of L. monocytogenes and other Listeria species, excluding the cheese isolate of L. seeligeri. Also, it was specific for L. monocytogenes when evaluated with Listeria-negative food enrichment cultures that were inoculated in the laboratory with Listeria species.

DNA Probes↗
PubMed1990

Trauma triage in western Sydney: results of a pilot study.

A pilot study of the effectiveness of prehospital triage of trauma patients was carried out in a western Sydney between February and July 1988. Triage guidelines were developed to identify seriously injured persons at the incident site who might warrant admission to a Level 3 Trauma Service Hospital (Trauma Centre), as part of the NSW Department of Health trauma services plan. The study results were based on 64% of ambulance trauma transports for which a triage decision was provided. Of trauma transports studied, 3.7% had injuries serious enough to warrant admission to Level 3 Trauma Service Hospital. Ambulance officers correctly triaged 77% of these cases in the field. However, 62% of trauma transports triaged 'severe' or 'critical' did not have injuries serious enough to warrant admission to a Level 3 Trauma Service Hospital. Nevertheless, the triage guidelines compared favourably with similar instruments used elsewhere. Based on the performance of the triage guidelines it was concluded that the introduction of a regionalized trauma service in metropolitan NSW with local bypass is possible.

Adolescent↗
PubMed1990

Natural killer and lymphokine-activated killer activities in stomach cancer patients with special emphasis on the effect of 5-fluorouracil, adriamycin and mitomycin-C chemotherapy.

The cytotoxicities of peripheral blood lymphocytes (PBL) and lymphokine-activated killer (LAK) cells were studied to evaluate the effect of chemotherapy on cellular immunity, in 18 patients with unresectable stomach cancer before and after chemotherapy with 5-fluorouracil, adriamycin and mitomycin-C (FAM), and in 21 healthy volunteers. LAK cells were generated in vitro by culturing PBL with 100 U recombinant human interleukin-2 (rH-IL-2)/ml for 72 h. K562 (human myelogenous leukemia), MKN-45 (human stomach adenocarcinoma) and PC-14 (human pulmonary adenocarcinoma) were used as target cells. The cytotoxicity of PBL to K562 and MKN-45 was suppressed in patients with stomach cancer before chemotherapy, compared with that in healthy volunteers (P less than 0.05). The cytotoxicity of LAK cells was significantly higher to all three cell lines tested than that of PBL in both the healthy volunteers and stomach cancer patients (P less than 0.01); however, a lower level of LAK activity was generated in patients with cancer compared to that in the healthy volunteers. FAM therapy did not suppress the cytotoxicities of PBL and LAK cells. The surface markers of PBL and LAK cells were measured, demonstrating that there was no significant change in the percentage of lymphocytes with CD3+, CD4+, CD8+, CD16+ or CD19+ after chemotherapy. The ratios of CD4+ to CD8+ cells in PBL and LAK cells were also not significantly changed after chemotherapy. In the present study, we have demonstrated that the PBL of stomach cancer were defective in generating LAK activity compared to those of controls, but the LAK activity generated from PBL receiving chemotherapy was similar to that from PBL without chemotherapy in stomach cancer patients.

Adult↗
PubMed1989

Enhancement of cytotoxicity of cisplatin in vitro by recombinant human tumor necrosis factor and/or recombinant human interferon-alpha, -beta and -gamma.

This study was conducted to investigate the modulatory effects of recombinant human tumor necrosis factor (rH-TNF) and recombinant human interferon (rH-IFN)-alpha, -beta and -gamma, either alone or in combination, on the cytotoxicity of cisplatin, using MTT assay, against MKN-45 (human stomach adenocarcinoma). MKN-45 was resistant to rH-TNF even at doses up to 10(3) U/ml. rH-IFN-gamma inhibited the survival of MKN-45 dose-dependently, while rH-IFN-alpha and -beta did not inhibit the survival of MKN-45 even at the highest concentrations tested (10(4) U/ml). Combination of rH-TNF with rH-IFN-alpha, -beta or -gamma did not significantly inhibit the survival of MKN-45, except for a combination of 10 U/ml of rH-TNF and 10(3) U/ml of rH-IFN-gamma (P less than 0.05). Cisplatin inhibited the survival of MKN-45 dose-dependently. By the simultaneous combination of cisplatin with rH-TNF and/or rH-IFN-alpha, -beta or -gamma, cytotoxicity of cisplatin was enhanced and the combination effects were additive. The effects of rH-TNF and rH-IFN-alpha, -beta and -gamma on the modification of cytotoxicity of cisplatin were evaluated in terms of modification index (MI), demonstrating that rH-TNF, rH-IFN-alpha, -beta and -gamma all augmented the cytotoxicity of cisplatin: MI values at 10(3) U/ml of rH-IFN-alpha, -beta and -gamma were 1.4, 1.4 and 2.3, respectively; those at the same concentrations of rH-IFN-alpha, -beta and -gamma in the presence of 10 U/ml of rH-TNF were 3.6, 2.5 and 5.1, respectively. These results demonstrating that the cytotoxicity of cisplatin was enhanced by rH-TNF and/or rH-IFN-alpha, -beta or -gamma suggest that cancer may be more effectively treated with the combination of cisplatin with these biological response modifiers than with cisplatin alone.

Adenocarcinoma↗
PubMed1989

Identification and characterization of a p53 gene mutation in a human osteosarcoma cell line.

The nuclear phosphoprotein p53 occurs at elevated levels in many transformed cells. Mutant forms of mouse p53 possess enhanced transforming activity compared with wild type p53. Mutant mouse p53 proteins form complexes with the 70 kDa family of heat shock proteins (HSPs). We previously demonstrated an association between p53 and the 70 kDa HSPs in the human osteosarcoma (HOS) derived cell line HOS-SL. We report here the molecular cloning and sequencing of the p53 gene from HOS-SL cells, and demonstrate that it is in fact mutant. Further, analysis of similar HOS-derived cell lines demonstrates that they also encode the same mutant form of p53, whereas the wild type form of p53 appears to be lost in these cells. Stability studies demonstrate an increased half life of the p53 protein in these cells, in keeping with its association with the HSP 70 proteins. A potential role for this p53 mutant in the transformation process is discussed.

Base Sequence↗
PubMed1979

Repair in arterial tissue. Endothelial regrowth, subendothelial tissue changes and permeability in the healing rabbit thoracic aorta.

The role of the endothelium and subendothelial connective tissue in the permeability of a healing intima was studied by vital staining with Evans blue and transmission electron microscopy after severe mechanical lesion of the rabbit aorta. Reendothelialization, decreasing permeability, and organization of neointimal connective tissue were concomitant events in the healing processes. The determinant factor in decreasing permeability was reendothelialization with the formation of endothelial flaps and junctions. Changes in the subendothelial connective tissue seemed also to be factors that influenced the permeability.

Animals↗
PubMed1979

Repair in arterial tissue. 2. Connective tissue changes following an embolectomy catheter lesion. The importance of the endothelial cells to repair and regeneration.

The neointimal hyperplasia following a severe mechanical lesion of the rabbit thoracic aorta was studied by vital staining with Evans blue and transmission electron microscopy. Neointimal tissue covered with endothelium contained organized laminated elastin-rich commective tissue. On the contrary neointimal connective tissue covered with pseudoendothelium was disorganized, with a tendency to fibrosis. Reendothelialization, re-establishment of intimal barrier function and formation of lamellated neointimal connective were parallel events. The importance of a intact subendothelial zone controlling healing processes is discussed. Interaction of endothelium and smooth muscle cells seems to be essential in the regulation of neointimal tissue formation and is probably implicated in a general vascular reactive pattern.

Animals↗
PubMed1977

Transformation of rat liver epithelial cells by Kirsten murine sarcoma virus.

We studied the transformation of epithelial, diploid cell lines (RL-33 and RL-34) derived from W rat liver by the Kirsten murine sarcoma virus. On days 4-5 after virus infection, the epithelial cells began to pile up focally, forming small projections and releasing round cells from the foci. The epithelial cells grew in chains or as islets and grew in suspension above the cells attached to the bottom of the flasks when the cultures reached the confluent stage. The virus titration pattern was "one-hit." Three classes of transformed cells were isolated with respect to virus release and antigen expression: 1) virus producer, 2) non-producer, and 3) sarcoma-positive, leukemia-negative cells. When transplanted sc into newborn rats, the transformed cells produced sarcomas. The transformed cells formed within 1-3 days larger aggregates than those of their normal counterpart cells when suspended in liquid growth medium above an agar base. Aggregate properties (size, viability, and proliferation) of transformed cells correlated with growth in soft agar and tumorigenicity. RNA-dependent DNA polymerase and type C virus particles were readily induced in the normal rat liver epithelial cells after exposure to 5-iodo-2'-deoxyuridine.

Animals↗
PubMed1976

Degree of sulfation in mucopolysaccharide sulfates in normal and stone-forming urines.

Mucopolysaccharides were extracted from both normal and stone-forming urines, and those from the stone-forming samples showed a higher degree of sulfation than those from normal urines, as determined by sulfate analysis and electrophoretic measurement. The sulfated mucopolysaccharides from stone-forming urines formed insoluble calcium salts, whereas those from normal urines generally remained soluble in the presence of calcium ion. Rachitic rat cartilage was found to have more highly sulfated mucopolysaccharides than normal rat cartilage. Highly sulfated mucopolysaccharides appear to be a significant factor in calcium stone formations.

Animals↗