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Biomedical subjects

S B Kim

Publications and source records attributed to S B Kim.

At least 19 recordsLinked to original sources

Annexin-I inhibits PMA-induced c-fos SRE activation by suppressing cytosolic phospholipase A2 signal.

Annexin-I (ANX-I) is a 37-kDa protein with a calcium-dependent phospholipid-binding property. Previously we have observed the inhibition of cytosolic phospholipase A2 (cPLA2) by ANX-I in the studies using purified recombinant ANX-I, and proposed a specific interaction model for the mechanism of cPLA2 inhibition by ANX-I [Kim et al. (1994) FEBS Lett. 343, 251-255]. Here we have studied the role of ANX-I in the cPLA2 signaling pathway by transient transfection assay. The stimulation of Rat2 fibroblast cells with phorbol 12-myristate 13-acetate (PMA) induced the c-fos serum response element (SRE). The SRE stimulation by PMA was dramatically reduced by (1) pretreatment with a cPLA2-specific inhibitor, arachidonyltrifluoromethyl ketone, or (2) co-transfection with antisense cPLA2 oligonucleotide, indicating that the SRE activation was through cPLA2 activation. Co-transfection with an ANX-I expression vector also reduced the SRE stimulation by PMA, suggesting the inhibition of cPLA2 by ANX-I. The active domain of ANX-I was mapped using various deletion mutants. ANX-I(1-113) and ANX-I(34-346) were fully active, whereas ANX-I(114-346) abolished the activity. Therefore the activity was in the amino acid 34 to 113 region, which corresponds to the conserved domain I of ANX-I.

Animals↗

Rapid microbore liquid chromatographic analysis of biphenyldimethyl dicarboxylate in human plasma with on-line column switching.

A fully automated method including microbore liquid chromatography and column switching was developed for the analysis of biphenyldimethyl dicarboxylate (DDB) from human plasma samples. After direct injection of plasma samples (100 microl) into the system, deproteinization and analyte fractionation occurred on a Capcell Pak MF Ph-1 column (20x4 mm I.D.) and the DDB fraction was transferred from the MF Ph-1 column to an intermediate column (35x2 mm I.D.) using 15% acetonitrile in phosphate buffer (50 mM, pH 7.0). The main separation was performed on a microbore C18 column (150x1.5 mm I.D.) using 45% acetonitrile in water. The method showed excellent sensitivity (detection limit of 5 ng/ml) and good precision (CV.< or =3.0%), and shortened total analysis time (20 min). In the concentration range of 5-200 ng/ml, the mean recovery was 90.7+/-1.8% and the response was linear (r2> or =0.999).

Chromatography, Liquid↗

Production of a nisin-like bacteriocin by Lactococcus lactis subsp. lactis A164 isolated from Kimchi.

Lactococcus lactis subsp. lactis A164 was isolated from Kimchi (Korean traditional fermented vegetables). The bacteriocin produced by strain A164 was active against closely related lactic acid bacteria and some food-borne pathogens including Staphylococcus aureus, Listeria monocytogenes and Salmonella typhimurium. The antimicrobial spectrum was nearly identical to that of nisin. Bacteriocin activity was not destroyed by exposure to elevated temperatures at low pH values, but the activity was lost at high pH values. This bacteriocin was inactivated by pronase E and alpha, beta-chymotrypsin, but not by trypsin, pepsin, and alpha-amylase. Cultures of L. lactis subsp. lactis A164 maintained at a constant pH of 6.0 exhibited maximum production of the bacteriocin. It was purified to homogeneity by ammonium sulphate precipitation, sequential ion exchange chromatography, and ultrafiltration. Tricine-SDS-PAGE of purified bacteriocin gave the same molecular weight of 3.5 kDa as that of nisin. The gene encoding this bacteriocin was amplified by PCR with nisin gene-specific primers and sequenced. It showed identical sequences to the nisin gene. These results indicate that bacteriocin produced by Lactococcus lactis A164 is a nisin-like bacteriocin.

Bacteriocins↗

Streptomyces thermocoprophilus sp. nov., a cellulase-free endo-xylanase-producing streptomycete.

The taxonomic position of a thermophilic actinomycete strain isolated from poultry faeces was examined using a polyphasic approach. The isolate, designated B19T, was assigned to the genus Streptomyces on the basis of chemotaxonomic and morphological criteria. An almost complete 16S rRNA gene (rDNA) sequence obtained for the test strain was compared with those of representative streptomycetes, notably thermophilic streptomycetes. 16S rDNA sequence data not only supported the assignment of the strain to the genus Streptomyces but also showed that the isolate formed a distinct phyletic line within the evolutionary branch composed of Streptomyces thermodiastaticus and related species. The strain was distinguished from related validly described Streptomyces species by a number of phenotypic properties. It is, therefore, proposed that strain B19T be classified in the genus Streptomyces as Streptomyces thermocoprophilus sp. nov.

Animals↗

Rhodococcus koreensis sp. nov., a 2,4-dinitrophenol-degrading bacterium.

A 2,4-dinitrophenol-degrading bacterial strain, DNP505T, which was isolated from an industrial wastewater, was taxonomically studied by a polyphasic approach using phenotypic, chemotaxonomic and genetic methods. Strain DNP505T has a cell wall of chemotype IV containing meso-diaminopimelic acid, arabinose and galactose. The predominant menaquinone is MK-8(H2). Mycolic acids contain 43-53 carbon atoms. Strain DNP505T has a cellular fatty acid profile containing straight-chain saturated, unsaturated and 10-methyl-branched fatty acids and has C16:0 as the major fatty acid. The DNA G+C content is 66 mol%. Strain DNP505T formed a coherent cluster with Rhodococcus species in a phylogenetic inference based on 16S rDNA sequences. Interestingly, strain DNP505T was found to have two types of 16S rDNA sequence, which showed 10 bp sequence differences (99.3% nucleotide similarity). Its differences in some phenotypic characteristics and its genetic distinctiveness indicate that strain DNP505T is separate from Rhodococcus species described previously. It is therefore proposed that strain DNP505T should be placed in the genus Rhodococcus as a new species, Rhodococcus koreensis. The type strain of the new species is strain DNP505T (= KCTC 0569BPT = JCM 10743T).

2,4-Dinitrophenol↗

Heat shock treatment protects human HL-60 cells from apoptosis induced by lectin II isolated from Korean mistletoe, Visum album var. Coloratum.

Mistletoe lectin II (ML II) isolated from Korean mistletoe (Viscum album var. Coloratum), an effective therapeutic agent for cancers, is known to induce cell death via apoptosis. In the present study, we found the protective effect of heat shock treatment of human leukemia HL-60 cells against ML II-induced apoptosis. Exposure of HL-60 cells to ML II for 4 h resulted in apoptosis of the cells, which was evaluated by examining "DNA ladder" formation and DNA fragmentation assay. The DNA fragmentation was significantly reduced in the cells subjected to heat shock treatment by incubation at 42 degrees C for 1 h and subsequently allowed to recover for 2-16 h at 37 degrees C, prior to exposure to ML II. HL-60 cells transfected with heat shock protein (hsp) 70 gene exhibited resistance to ML II-induced apoptosis very similar to that seen when untransfected cells were heat-shocked. These results indicate that ML II-induced apoptosis in HL-60 cells is inhibited by heat shock treatment, at least in part, via a hsp 70-mediated mechanism.

Apoptosis↗

Protein kinase A or C modulates the apoptosis induced by lectin II isolated from Korean mistletoe, Viscum album var. Coloratum, in the human leukemic HL-60 cells.

Mistletoe lectins (MLs) are increasingly used as an anticancer drug in the treatment of human tumors. The cytotoxic activity of MLs against tumor cells is due to programmed cell death (apoptosis). The up- or down-regulation of protein kinase A (PKA) or C (PKC) is known to be associated with the regulation of drug-induced apoptosis. Previously, we isolated cytotoxic MLII from the extract of Korean mistletoe (Viscum album var. Coloratum) and characterized its biochemical properties. The present study was designed to investigate the role of PKA and PKC in MLII-induced apoptosis. Exposure of human leukemia HL-60 cells to various doses of MLII resulted in apoptosis. However, the treatment of these cells with dibutyl-cyclic AMP (DB-cAMP), PKA activator, or 12-O-tertadecanoyl phorbol 13-acetate (TPA), PKC activator, suppressed MLII-induced apoptosis. Furthermore, KT5720 and staurospoline, PKA and PKC inhibitors, respectively, reversed the suppression by DB-cAMP and TPA in the MLII-induced apoptosis of HL-60 cells. These results suggest that the activation of PKA or PKC was involved in the suppression of MLII-induced apoptosis in HL-60 cells. Collectively, these results indicate that activation of PKA or PKC in HL-60 cells may confer protection against MLII-induced apoptosis.

Apoptosis↗

The possible cost effectiveness of peripheral blood stem cell mobilization with cyclophosphamide and the late addition of G-CSF.

The purpose of this study was to develop a cost-effective protocol for the mobilization of peripheral blood stem cells (PBSC) in patients with malignancy. Thirty consecutive patients were randomized to mobilize PBSC with the late addition of a standard 250 microg dose of G-CSF (Neutrogen) from day 8 or early addition of the same dose of G-CSF from day 2, following cyclophosphamide (CY) 4 g/m2. The median yield of CD34+ cells from evaluated patients was 7.87 x 10(6)/kg (range, 2.06-27.25), collected in a median of four apheresis (range, 2-9). Target CD34 + cell doses > or = 2.0 x 10(6)/kg were achieved in all patients able to be evaluated. There were no statistically significant differences in CD34+ cell yields or toxicities. Overall engraftment occurred with median days to neutrophils > or = 0.5 x 10(9)/L or platelets > 20 x 10(9)/L of 11 and 17 days, respectively. However, the duration of G-CSF administration was markedly shorter in the late use of G-CSF group than in the early use of G-CSF group, with a median of 9 days compared with 15 days (p<0.001). PBSC harvesting after priming with CY plus delayed use of G-CSF made it a safe and cost-effective procedure.

Adult↗

Isolation and characterization of biologically active lectin from Korean mistletoe, Viscum album var. Coloratum.

A mistletoe lectin was isolated from water extracts of Korean mistletoe, a subspecies of Viscum album, grown on Quercus mongolica using CM-Sepharose chromatography followed by an affinity chromatography on a concanavalin A-Sepharose column. The compound proved to be a mistletoe lectin II with D-galactose and N-acetyl-D-galactosamine specificity. Matrix-assisted laser desorption time-of-flight mass spectroscopy showed it to have an average molecular mass of 62.7 kDa and to consist of two subunits of 30.6 kDa and 32.5 kDa. It was a basic protein with isoelectric points of 9.4 and 9.6 by capillary isoelectric focusing and was cytotoxic to Molt4 cell.

Humans↗

Effect of increasing serum albumin on plasma D-dimer, von Willebrand factor, and platelet aggregation in CAPD patients.

This study was performed to investigate the interrelation between blood albumin level and D-dimer (a marker of intravascular coagulation) and von Willebrand factor (vWF; a marker of endothelial injury) levels or platelet aggregation. Blood levels of albumin, D-dimer, vWF, and C-reactive protein (CRP) and the threshold aggregating concentration (TAC) of ristocetin were measured in 64 continuous ambulatory peritoneal dialysis (CAPD) patients and compared with 36 healthy controls. Twenty-two CAPD patients with albumin levels less than 3.0 g/dL were divided into experimental and disease-control groups. In the experimental group, levels were measured before and after repeated infusions of 20% albumin, 100 mL/d for 7 days. The same parameters were measured in the disease-control group that did not receive the albumin infusion. CAPD patients had higher D-dimer and vWF levels than the healthy controls. There were inverse correlations between albumin and D-dimer (r = -0.48; P < 0.001), vWF (r = -0.29; P < 0.05), or logCRP (r = -0.44; P < 0.001) in CAPD patients. There were positive correlations between logCRP and D-dimer (r = 0.38; P < 0.01) and between logCRP and vWF (r = 0.32; P = 0.01) in CAPD patients. No change was seen in D-dimer, vWF, and CRP levels in either group. The TAC of ristocetin in the 18 CAPD patients was not different from that in the 11 healthy controls (0.55 +/- 0.09 v 0.65 +/- 0.07 mg/mL). There was a correlation between albumin level and TAC in the CAPD patients (r = 0.59; P < 0.01). TAC increased from 0.50 +/- 0.09 to 0.62 +/- 0.13 mg/mL (123% +/- 17%; P < 0.05; n = 6) at the end of the repeated albumin infusions in the experimental group, whereas it did not change in the control group. CRP level did not change in either group. The results of this study indicate that hypoalbuminemia increases platelet aggregability. The observation that the albumin infusion was not associated with changes in D-dimer and vWF despite the inverse correlations suggests that these relationships may be secondary to other factors, such as inflammation.

Adult↗

A cross-sectional study comparing the nutritional status of peritoneal dialysis and hemodialysis patients in Korea.

OBJECTIVE: This study was performed to compare the nutritional status of peritoneal dialysis (PD) and hemodialysis (HD) patients in Korea and to validate the nutritional assessment method. DESIGN: For nutritional assessment, we used five nutrition-related indicators, including percentage unplanned weight loss, percentage ideal body weight (IBW), serum albumin, appetite and intake, and any gastrointestinal symptoms affecting intake. A 1-month food frequency interview was conducted by clinical dietitians using food models to estimate energy and protein intake. The validity of the nutritional assessment method was tested by objective measures. PATIENTS/SETTING: A cross-sectional study was conducted in our center for 51 PD patients and 169 HD patients who met the study criteria. In the study, HD patients typically underwent dialysis three times per week, and most PD patients performed four 2-L dialysis exchanges every day. RESULTS: Our data showed a higher incidence of malnutrition in PD patients than in HD patients (33% v 18%) and in diabetics than in nondiabetics. Age, height, and dietary energy intake of the two groups were comparable. In PD patients, however, duration of dialysis treatment (23.9 +/- 19.1 months v 41.8 +/- 31.7 months, P < 0.001) and serum albumin (35.2 +/- 5.0 g/L v 39. 7 +/- 3.4 g/L, P < 0.0001) were significantly lower, whereas percentage IBW (108.1% +/- 12.4% v 96.2% +/- 11.6%, P < 0.0001) and dietary protein intake (1.12 +/- 0.34 g/kg IBW v 0.98 +/- 0.31 g/kg IBW, P < 0.05) were significantly higher than in HD patients. In malnourished PD and HD patients, percentage IBW, serum albumin, dietary energy, and protein intake were significantly lower than in well-nourished counterparts. CONCLUSION: A higher incidence of malnutrition was observed in PD patients than in HD patients. Nutritional profile of PD patients was different from that of HD patients. Higher body weight and lower serum albumin in PD patients did not seem to be related to dietary energy and protein intake. The five nutritional indicators can be used as a simple inexpensive and reliable method for the early detection of malnutrition in dialysis patients.

Adult↗

Association of plasma fibrinogen concentration with vascular access failure in hemodialysis patients.

BACKGROUND: Elevated plasma fibrinogen is an important risk factor for coronary artery disease in the general population and patients with chronic renal failure. High plasma fibrinogen may trigger thrombus formation in arteriovenous fistulas. We performed a prospective, cohort study to evaluate the association of plasma fibrinogen concentration with vascular access failure in patients undergoing long-term haemodialysis. METHODS: Between September 1989 and October 1995, 144 patients underwent a vascular access operation. In March 1997, 102 patients (56 M, 46 F) who had been followed up for more than 18 months (median; 37 months, range; 18-102 months) were included in the study. The median age of the patients was 52 years (range; 19-78 years). In 35 patients, renal disease was secondary to diabetes mellitus. The type of vascular access was a polytetrafluoroethylene (PTFE) graft in 17 patients. Seventy-seven patients received recombinant human erythropoietin (r-HuEPO) therapy during the follow-up period. Plasma fibrinogen, albumin, total cholesterol, hematocrit, platelets and creatinine were measured at the time of operation. Vascular access failure was defined as the occurrence of complications requiring transluminal angioplasty, thrombolytic therapy or surgical repair. RESULTS: Thirty-eight patients had at least one vascular access failure and the incidence was 0.3 (range; 0-2.4) episodes per patient-year. The survival rate of vascular access was 78% (native fistula; 80%, PTFE graft; 71%) after 12 months and 70% (native fistula; 73%, PTFE graft; 51%) after 24 months. Older age, a PTFE graft, r-HuEPO therapy, higher hematocrit, lower albumin and higher fibrinogen levels were significantly associated with vascular access failure, whereas gender, diabetes mellitus, total cholesterol and platelet count were not. Plasma fibrinogen was inversely correlated with albumin (r=-0.38, P=0.001). The cumulative vascular access survival was significantly lower in patients with high plasma fibrinogen levels (> or = 460 mg/dl) compared with patients with low levels (< 460 mg/dl) (P=0.007). Independent risk factors for vascular access failure analysed by Cox's proportional hazards model were older age (RR; 1.36 by 10-year increment), higher fibrinogen level (RR; 1.20 by 100 mg/dl increment), PTFE graft (RR; 2.28) and r-HuEPO therapy (RR; 3.79). CONCLUSION: High plasma fibrinogen level is an independent risk factor for vascular access failure in haemodialysis patients.

Adult↗

Reclassification of Amycolatopsis rugosa Lechevalier et al. 1986 as Prauserella rugosa gen. nov., comb. nov.

An almost complete sequence of the 16S rDNA of the type strain of Amycolatopsis rugosa was determined following direct sequencing of the amplified gene. The sequence was aligned with those of representatives of the family Pseudonocardiaceae and related actinomycetes and phylogenetic trees were inferred by using three tree-making algorithms. The organism formed a distinct clade within the evolutionary radiation occupied by the family Pseudonocardiaceae. It was also readily distinguished from all of the validly described genera classified in this taxon by using a combination of chemical and morphological markers. On the basis of these genotypic and phenotypic differences, the name Prauserella gen. nov. is proposed for a new genus containing the previously misclassified Amycolatopsis rugosa. The type strain of Prauserella rugosa is DSM 43194T (= ATCC 43014T = NCIMB 8926T).

Actinomycetales↗

Amycolatopsis thermoflava sp. nov., a novel soil actinomycete from Hainan Island, China.

A soil isolate, which had been assigned to the genus Nocardia, was shown to have properties consistent with its classification in the genus Amycolatopsis. An almost complete nucleotide sequence of the 16S rDNA of the strain was determined following cloning and sequencing of the amplified gene. The sequence was aligned with those available for members of the family Pseudonocardiaceae and related taxa and phylogenetic trees were inferred using three tree-making algorithms. The organism consistently formed a distinct monophyletic clade with the type strain of Amycolatopsis methanolica, but DNA-DNA relatedness data showed that the two strains belonged to distinct genomic species. The organism was also distinguished from the type strains of all validly described species of Amycolatopsis using a battery of phenotypic properties. The genotypic and phenotypic data show that the strain merits recognition as a new species of the genus Amycolatopsis. The name proposed for the new species is Amycolatopsis thermoflava sp. nov. The type strain is IFO 14333T.

Actinomycetales↗

Streptomyces malaysiensis sp. nov., a new streptomycete species with rugose, ornamented spores.

The taxonomic position of a streptomycete strain isolated from Malaysian soil was established using a polyphasic approach. The organism, designated strain ATB-11T, was found to have chemical and morphological properties consistent with its classification in the genus Streptomyces. An almost complete 16S rRNA gene (rDNA) sequence determined for the test strain was compared with those of previously studied streptomycetes by using two treeing algorithms. The 16S rDNA sequence data not only supported classification of the strain in the genus Streptomyces but also showed that it formed a distinct phyletic line. At maturity, the aerial hyphae of strain ATB-11T differentiated into tight, spiral chains of rugose, cylindrical spores. The organism was readily distinguished from representatives of validly described Streptomyces species with rugose spores by using a combination of phenotypic features. It is proposed, therefore, that strain ATB-11T be classified in the genus Streptomyces as Streptomyces malaysiensis sp. nov.

Bacterial Typing Techniques↗

Gordonia desulfuricans sp. nov., a benzothiophene-desulphurizing actinomycete.

The taxonomic position of two actinomycetes isolated from soil was established using a polyphasic approach. The organisms, designated 213ET and 213F, were found to have chemical and morphological properties consistent with their assignment to the genus Gordonia. Nearly complete sequences of the 16S rDNA genes of the two strains were determined following the isolation and direct sequencing of the amplified genes. The tested strains were found to have identical 16S rDNA sequences and formed a phylogenetic line within the evolutionary radiation occupied by the genus Gordonia that was most closely related to Gordonia rubropertincta DSM 43197T. However, DNA-DNA relatedness data showed that strain 213ET and Gordonia rubropertincta DSM 43197T belonged to distinct genomic species. Strains 213ET and 213F also shared an identical phenotypic profile which distinguished them from representatives of validly described Gordonia species. The combined genotypic and phenotypic data show that strains 213ET and 213F merit recognition as a new species of Gordonia. The name proposed for the new species is Gordonia desulfuricans, for which the type strain is 213ET (= NCIMB 40816T).

Actinomycetales↗

Oligomycin sensitivity of mitochondrial F(1)F(0)-ATPase in diabetes-prone BHE/Cdb rats.

BHE/Cdb and Sprague-Dawley rats differ in their mitochondrial DNA sequence for the ATPase 6 ("subunit a") gene. Base substitutions in this sequence result in the substitution of asparagine for aspartate at position 101 and the substitution of serine for leucine at position 129. Differences in sensitivity to oligomycin were observed. When the isolated F(1)F(0)-ATPase complex was studied and ATPase activity was assessed, that which was isolated from the BHE/Cdb rats was less sensitive to oligomycin inhibition than that which was isolated from the Sprague-Dawley rats. In contrast, when oxygen consumption was measured [oxygen phosphorylation (OXPHOS)] and a dose-response curve was generated with isolated mitochondria from these two strains, there was a shift to the left for the BHE/Cdb rat mitochondria. These mitochondria were more sensitive to oligomycin inhibition of OXPHOS than were mitochondria isolated from Sprague-Dawley rats. The OXPHOS results are consistent with those from human fibroblasts having either a normal or mutated ATPase 6 gene.

Animals↗

Hyperfibrinogenemia is an independent risk factor for atherosclerotic renal artery stenosis.

It is important to identify patients at risk for atherosclerotic renal artery stenosis because renal artery stenosis is a progressive disease and a potentially correctable problem. To determine the risk factors for atherosclerotic renal artery stenosis, we performed renal arteriography at the time of cardiac catheterization in 270 patients (M:F, 193:77, mean age: 59 years) with clinical ischemic heart disease. Before the procedure, demographic data, medical history, physical findings and laboratory data were obtained. The degree of coronary artery stenosis and renal artery stenosis was quantified with automatic edge detection technique. Significant renal artery stenosis, defined as a narrowing of the diameter by more than 50%, was identified in 28 (10%) patients. Three patients (1%) had bilateral disease. Significant coronary artery disease, defined as a narrowing of the diameter by more than 50%, was present in 231 patients (85%). By univariate logistic regression analysis, older age (68 +/- 8 vs. 58 +/- 10 years), the presence of hypertension (61% vs. 38%), the extent of coronary artery disease, a high fibrinogen level (391 +/- 93 mg/dl vs. 335 +/- 109 mg/dl), a low albumin level (3.9 +/- 0.4 g/dl vs. 4.1 +/- 0.4 g/dl), and a low hemoglobin level (12.5 +/- 1.6 g/dl vs. 13.5 +/- 1.6 g/dl) were associated with the presence of renal artery stenosis (p < 0.05). Serum lipids, lipoprotein(a), creatinine, sex, smoking, or diabetes were not associated. By multivariate logistic regression analysis, older age (OR: 2.43 analyzed by 10 years increment, p = 0.0001), the presence of hypertension (OR: 2.68, p = 0.039) and a higher fibrinogen level (OR: 1.63 analyzed by 100 mg/dl increment, p = 0. 038) were significant risk factors of renal artery stenosis. Fibrinogen level was negatively correlated with albumin level (r = -0.18, p = 0.004). These results suggest that hyperfibrinogenemia as well as old age and hypertension are independent risk factors for atherosclerotic renal artery stenosis.

Aged↗