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Biomedical subjects

B K Kim

Publications and source records attributed to B K Kim.

At least 73 records · Page 4Linked to original sources
PubMed1999

Cloning and cytotoxicity of fusion proteins of EGF and angiogenin.

Targeted toxins represent a new approach to specific cytocidal therapy. Immunotoxins based on plant and microbial toxins are very immunogenic. To develop a targeted therapy that is less immunogenic and easily invades target tissues, four fusion proteins containing human angiogenin targeted by human EGF have been constructed. EGF is a single chain polypeptide, which binds to epidermal growth factor receptor (EGFR) and is known to be internalized by endocytosis. Angiogenin has been separately fused either at the amino terminus or the carboxyl terminus of EGF via linkers, giving rise to angiogenin-gly-EGF, angiogenin-(gly)4ser-EGF and EGF-angiogenin, EGF-gly-angiogenin, respectively. The fusion proteins were over-expressed in Escherichia coli and purified from periplasmic eluents by affinity chromatography. EGF-angiogenin and EGF-gly-angiogenin maintained receptor-binding activity of EGF and RNase activity of angiogenin in a single peptide and actively inhibited growth of human EGFR-positive target cells in culture. They are expected to have a very low immunogenic potential in humans because of their endogenous origin and also to have another potential therapeutic advantage because these fusion proteins may have overcome conventional immunotoxin and possess increased ability to penetrate because of their small size.

Angiogenesis Inducing Agents↗
PubMed1999

Antiproliferative effect of a vitamin D3 analog, EB1089, on HL-60 cells by the induction of TGF-beta receptor.

EB1089 is a novel 1,25(OH)2D3 analog that has more potent antitumor properties with reduced hypercalcemic effects than 1,25(OH)2D3. We investigated the role of transforming growth factor-beta1 (TGF-beta1) in the growth inhibition of human acute myeloid leukemia cell line, HL-60, by EB1089. Clonal growth of HL-60 cells was inhibited in a dose-dependent manner by EB1089. Although TGF-beta1 alone slightly inhibited proliferation of HL-60 cells, the addition of TGF-beta1 into culture treated with 10(-8) M of EB1089 showed a significant synergistic antiproliferative effect in a dose-dependent manner. EB1089 up-regulated the expression of TGF-beta receptor type I (TGF-beta RI), type II (TGF-beta RII) and TGF-beta1. Antiproliferative effect of EB1089 was partially reversed by TGF-beta1 neutralizing antibody (anti-TGF-beta1). Vitamin D receptor (VDR) expression was increased by TGF-beta1, suggesting synergistic action of TGF-beta1 and EB1089. Combined treatment of EB1089 and TGF-beta1 resulted in an increased expression of cyclin-dependent kinase inhibitor (CDKI), p27 protein, compared to either ligand alone. Up-regulation of p27 protein expression by either TGF-beta1 or EB1089 was reduced by anti-TGF-beta1. These findings suggest that TGF-beta1 is involved in the antiproliferative effect of EB1089 on HL-60 cells.

Activin Receptors, Type I↗
PubMed1999

Phenotypic characteristics of Enterococcus faecium variants confirmed by intergenic ribosomal polymerase chain reaction and E. faecium polymerase chain reaction.

Enterococcus faecium has recently emerged as a serious nosocomial pathogen. The emergence of multiple antimicrobial agent-resistant E. faecium has been remarkable; with its strains it is one of the most phenotypically heterogeneous of all enterococcal species. About 15% of enterococcal strains isolated from human clinical specimens were found to have atypical biochemical characteristics. In order to determine if these strains were E. faecium variants, intergenic ribosomal polymerase chain reaction (ITS-PCR) and E. faecium PCR (EfPCR) were performed in 45 atypical strains, and the two PCR results were used to analyze phenotypic characteristics of the strains. As many as 60% (27/45) of the atypical strains were identified as E. faecium. Thus, it is concluded that if an enterococcal strain shows positive reaction to arabinose, arginine, and ribose and negative reaction to methyl-alpha-D-glucopyranoside and pigment, it should be identified as E. faecium.

Bacterial Typing Techniques↗
PubMed1999

High level expression of soluble angiogenin in Escherichia coli.

Human angiogenin was genetically engineered and contained the E. coli Omp A signal sequence for secreting soluble angiogenin to the periplasm under tac promoter control. The angiogenin sequence was encoded in a single gene and expressed as a 14.4 kilodalton soluble protein in E. coli. It was purified by CM-Sepharose ion-exchange chromatography and by a heparin-Sepharose affinity chromatography procedure. The biological activity of angiogenin was established by its ability to inhibit mRNA-dependent rabbit reticulocyte cell-free translation.

Bacterial Outer Membrane Proteins↗
PubMed1999

Combined peripheral facial and abducens nerve palsy caused by caudal tegmental pontine infarction.

Isolated peripheral facial and abducens nerve palsy could theoretically be caused by a caudal pontine infarction, but as far as we know, there has been no published case history which has demonstrated this point. We describe the cases of two hypertensive patients who showed combined peripheral facial and abducens nerve palsy without other neurologic symptoms or signs. Other than hypertension, there was no identifiable etiology. Magnetic resonance imaging demonstrated compatible isolated ipsilateral ischemic infarction of the caudal tegmental pons. The present cases indicate that a well-placed small pontine infarction can cause isolated peripheral facial and abducens nerve palsy.

Abducens Nerve↗
PubMed1999

Crescentic glomerulonephritis: a clinicopathologic analysis of 17 cases with emphasis on glomerular and interstitial neutrophil infiltration.

In order to determine the extent to which specific forms of glomerulonephritis (GN) contribute to the pool of crescentic GN, renal tissues from 17 crescentic GN patients were examined with special attention to glomerular and interstitial neutrophil infiltration. Renal tissues from five normal kidneys served as normal controls. Renal biopsy tissues from five patients with postinfectious GN in which crescent formation was not observed were also examined as disease controls. The patients were put into both three groups according to immunofluorescence findings and two groups according to the active or inactive phase of the crescents: group 1 with anti-glomerular basement membrane crescentic GN, one case; group 2 with immune complex crescentic GN, ten cases; and group 3 with pauci-immune crescentic GN, six cases. Four of the nine individuals tested were positive for anti-neutrophil cytoplasmic antibody (44.4%). Glomerular and interstitial neutrophil infiltrations were prominent in both the active and inactive phase groups, compared to normal controls (p<.05). Glomerular neutrophil infiltration was significantly prominent in the active phase group, compared to the inactive phase group (p<.001). In both the active and inactive phase groups, interstitial neutrophil infiltration was prominent, compared to disease control groups (p<.05). These results support the concept of the participation of periglomerular leukocytes in the renal tissue damage of crescentic GN, although the role of neutrophils was not examined.

Adult↗
PubMed1999

Four cases of therapy-related leukemia.

Combination chemotherapy and radiation therapy have contributed to the successful treatment of various cancer patients. But the development of second malignancies is an inevitable complication of long-term cytotoxic treatment. The most serious and frequent of such complications is acute myelogenous leukemia (AML). Therapy-related leukemia is generally fatal. Since the number of patients exposed to chemotherapy is increasing each year, the clinical significance of this entity cannot be underestimated. There have been many investigations of therapy-related leukemia, but in Korea published reports are rare. We describe four such cases, involving one older female with lung cancer and three children with acute lymphoblastic leukemia (ALL) and malignant lymphoma. Alkylating agents were used for chemotherapy, and in one case, topoisomerase II inhibitor. Irrespective of the causative agents, the latency periods were relatively short, and despite induction chemotherapy in two, all survived for only a few months. During the follow-up of patients treated for primary malignancies, the possibility of therapy-related leukemia should always be borne in mind.

Adolescent↗
PubMed1999

Behcet's disease associated with myelodysplastic syndrome: a case report.

A rare case of Behcet's disease associated with myelodysplastic syndrome (MDS) is described. A 50-year-old Korean female suffering recurrent oral ulcer, genital ulcer, fatigue, arthralgia in both knees and fever was diagnosed as Behcet's disease. The findings of bone marrow aspirates were consistent with refractory anemia, a subtype of myelodysplastic syndrome. Chromosomal analysis of bone marrow cells revealed 46,XX,-8,-20,+der(8)t(8;20)(p23;p10),+der(8) t(8;20)(p23;q10)[30]. The chromosomal changes found in this patient were different from those of previous reports, which mostly revealed trisomy 8. If anemia, low reticulocyte count and dyspoietic cells are sustained in Behcet's disease, physicians should be alert to the possibility of MDS with aberration in chromosome 8 and perform a bone marrow study for the proper diagnosis and treatment of the disease. We presented a case of Behcet's disease associated with MDS, which is the first Korean case.

Anemia↗
PubMed1998

Effects of steroid hormones and cyclosporine A on taurine-transporter activity in the RAW264.7 cell line.

The activity of the taurine transporter is affected by various extracellular stimuli, such as ions, hormones and stress. To assess the effects of steroid hormones and cyclosporine A (CsA) on taurine-transporter activity, the murine monocytic cell line, RAW264.7, was stimulated with dexamethasone (DM), triamcinolone (TA), cortisone (CS), hydrocortisone (HCS), prednisone (PSN), prednisolone (PSL) and methylprednisolone (MPSL) in the presence of 12-O-tetradecanoylphorbol 13-acetate (TPA). Treatment of the cell with TPA led to a significant reduction in taurine-transporter activity. However, in the case of the stimulation of the cells with steroid hormones in the presence of TPA, all of the hormones reversed the TPA-induced reduction in the taurine-transporter activity. Treatment of the cells with CsA led to a significant reduction in taurine-transporter activity, but ionomycin (IM) alone did not affect taurine-transporter activity. However, IM reversed the TPA- and CsA-induced reduction in taurine-transporter activity. These results showed that both IM and the glucocorticoid hormones reversed TPA-induced reductions in taurine-transporter activity but only IM reversed the CsA-induced reduction of transporter activity in the RAW264.7 cell line.

Animals↗
PubMed1998

Taurine can ameliorate inflammatory bowel disease in rats.

We previously reported that the protective effect of taurine against indomethacin-induced gastric mucosal injury was due to its antioxidant effects which inhibited lipid peroxidation and neutrophil activation. In this study, we examined the effect of taurine on reducing the inflammatory parameters of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) in rats. To induce IBD, rats were given ethanolic TNBS intracolonically. The rats then received 500 mg/kg/day of taurine per orally. The rats were sacrificed one week after IBD induction. Ulceration and inflammation of the distal colon with formation of granuloma in the vehicle-treated IBD rats after two days of administration of TNBS were observed. Treatment with 0.5 g/kg of taurine by the oral route ameliorated colonic damage and decreased the incidence of diarrhea and adhesions. Colon weight (an index of tissue edema) was markedly increased in the IBD rats after administration of TNBS, but was significantly lower after taurine treatment. Myeloperoxidase (MPO) activity in the vehicle-treated IBD rats was substantially increased compared with that of the control. The taurine-treated animals showed reduced MPO activity (35% lower) when compared with that of the vehicle-treated animals. Taurine treatment decreased basal and formyl-methionyl leucyl phenylalanine (FMLP) stimulated reactive oxygen generation in colonic tissue of the IBD rat compared with vehicle treatment after one week. These results suggest that administration of taurine reduced the inflammatory parameters in this rat model of IBD by increasing the defenses against oxidative insult.

Animals↗
PubMed1998

Distribution of bacteria with the arylsulfate sulfotransferase activity.

This study is to predict the possible roles of the arylsulfate sulfotransferase (ASST) in the microorganism. At first we studied the spectrum of a distribution of the ASST enzyme through about 1,300 bacteria and the several selected strains were compared with Klebsiella K-36 previously reported in the level of DNA homology using the Southern blot method. From this study, we could predict that this enzyme would not exist in specific bacteria and it might not be a critical enzyme for the life of bacteria.

Arylsulfotransferase↗
PubMed1998

Prolonged systemic delivery of streptokinase using liposome.

To prolong the biological half-life of streptokinase, a thrombolytic agent, streptokinase-bearing liposome with and distearolyphosphatidyl ethanolamine-N-poly (ethylene glycol) 2000 (DSPE-PEG 2000) was prepared and evaluated. Streptokinase-bearing liposomes composed of distearolyphosphatidylcholine (DSPC), cholesterol and cholesterol-3-sulfate with DSPE-PEG 2000 was prepared by the freeze-thawing method and administered via femoral vein to rats (15,000 IU/kg). The activity of streptokinase in plasma was determined by the method based on the amidolytic activity of streptokinase-plasminogen complex. Pharmacokinetic parameters of streptokinase incorporated in liposomes were compared with those of streptokinase alone. The T1/2 and AUCinfinity of streptokinase incorporated in DSPC-PEG liposome increased 16.3- and 6.1-fold, respectively, compared with those of streptokinase alone. Streptokinase-bearing long-circulating liposome could increase the circulation time of streptokinase in blood and expect longer thrombolytic activity compared with streptokinase alone.

Animals↗
PubMed1998

Resistance mechanism of Acinetobacter spp. strains resistant to DW-116, a new quinolone.

DW-116 is a new fluoroquinolone antimicrobial agent with a broad spectrum. In order to elucidate the resistance mechanism to DW-116 in Acinetobacter spp. bacteria, total chromosomal DNA was isolated from 10 strains of Acinetobacter spp. resistant to DW-116. Quinolone resistance determinant region (QRDR) of DNA gyrase gene was amplified by PCR. The 345 bp nucleotide fragment yielded was inserted into pKF 3 which was used as the vector. Comparisons of the DNA sequences of 8 strains with that of the wild type strain revealed a Ser-83 to Leu mutation in mutants and all ten strains contained one silent mutation(T-->G) in QRDR. From Acinetobacter MB4-8 strain, DNA gyrase was isolated and purified, through no-vobiocin-sepharose, heparin-sepharose affinity column chromatography. The enzyme was composed of two subunits and the molecular mass of subunits A and B were 75.6 and 51.9 kDa, respectively. The supercoiling activity of the reconstituted DNA gyrase composed of subunit A from Acinetobacter MB4-8 and subunit B from E. coli was not inhibited by 128 micrograms/ml of ciprofloxacin. It might be said that one of the resistance mechanisms to DW-116 in A-cinetobacter MB4-8 was subunit A alteration of DNA gyrase.

Acinetobacter↗
PubMed1998

Physicochemical properties of recombinant hepatitis B surface antigen expressed in mammalian cell (C127).

The physicochemical properties of recombinant hepatitis B surface antigen (r-HBsAg), which was expressed in C127 mammalian cell were studied. Using roller bottle culture in DMEM supplemented with fetal bovine serum, 10-15 mg/L of r-HBsAg was produced with about 31% of purification yield. The purity of r-HBsAg by HPLC was 99.8% and electron microscopic examination showed homogeneous spherical particle with 22 nm in diameter, a morphological characteristic of HBsAg. The density of r-HBsAg by CsCl density gradient method was 1.19 g/ml and the isoelectric point by Mono P HR 5/20 column was 4.6. The analysis of subunit protein pattern using SDS-PAGE followed by scanning densitometry gave 81.3% of S protein and 18.7% of pre-S protein. Fluorophore-assisted-carbohydrate-electrophoresis analysis showed the relative amount of carbohydrate to protein was 1.7% and its major component was N-acetyl glucosamine, which was about 39% of total carbohydrate. The relative amount of lipid to protein determined by vanillin phosphoric acid method was 32.5% and its major component was phospholipid, which was about 70% of total lipid. The physicochemical properties of C127 mammalian cell-derived r-HBsAg are similar to those of p-HBsAg, suggesting that the r-HBsAg can be used in developing a new preventive vaccine against hepatitis B.

Animals↗
PubMed1998

Protective effect of taurine on TNBS-induced inflammatory bowel disease in rats.

We had previously reported that the protective effect of taurine against indomethacin-induced gastric mucosal injury was due to its antioxidant effects, which inhibited lipid peroxidation and neutrophil activation. In this study, we examined the effect of taurine on reducing the inflammatory parameters of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) in rats. In order to induce IBD, ethanolic TNBS was given to rats intracolonically. Then they received 500 mg/kg/day of taurine orally and were sacrificed one week after IBD induction. While ulceration and inflammation of distal colon with formation of granuloma in the vehicle-treated IBD rats two days after administration of TNBS were observed, treatment with taurine ameliorated colonic damage and decreased the incidence of diarrhea and adhesion. Also, colon weight as an index of tissue edema, which was markedly increased in the IBD rats, became significantly lower after taurine treatment. Myeloperoxidase (MPO) activity in the vehicle-treated IBD rats was substantially increased, compared with that of normal control. The taurine-treated animals significantly reduced MPO activity (35% lower) when compared with that of the vehicle-treated animals. Taurine treatment decreased both basal and formyl-methionyl leucyl phenylalanine-stimulated reactive oxygen generation from colonic tissue in the IBD rats. These results suggest that the administration of taurine reduce the inflammatory parameters in this IBD rat model by increasing defending capacity against oxidative damage.

Animals↗
PubMed1998

Immunological properties of recombinant hepatitis B surface antigen expressed in mammalian cell (C127).

We examined the immunological properties of the recombinant hepatitis B surface antigen (r-HBsAg) which was expressed in mammalian cell (C127). The cross-immunity of r-HBsAg and plasma-derived hepatitis B surface antigen (p-HBsAg) were tested using Western blotting and ELISA with guinea pig polyclonal antibody and naturally infected human-derived antibody and the both antigens show the same results in their response pattern and intensity, which indicate they have a good cross-immunity. From the measurement of ED50 after formalin- or heat-inactivation, both r-HBsAg and p-HBsAg showed ED50 of 0.2-0.3 in formalin-inactivation, while r-HBsAg was 0.05-0.09 and p-HBsAg was 0.03-0.07 in heat-inactivation, which means heat-inactivation method is 3-4 times superior in immunogenicity. In the immunopersistency test performed in guinea pig for the period of 3 months with two different adjuvants, antibody titer was 34.2 with muramyl dipeptide adjuvant, which was 1.8 times greater than the antibody titer of 18.9 with AlPO4 adjuvant. The mutagenicity of r-HBsAg, examined by Ames test and micronucleus test, were all negative. In conclusion, r-HBsAg has the same cross-immunity with p-HBsAg, and heat-inactivation method and muramyl dipeptide adjuvant allow development of r-HBsAg vaccine with excellent immunogenicity.

Adjuvants, Immunologic↗