Biomedical subjects

Hyung Jin Kim

Publications and source records attributed to Hyung Jin Kim.

At least 19 recordsLinked to original sources

PubMed2006

Factors associated with automobile accidents and survival.

This paper develops an econometric model for vehicles' inherent mortality rate and estimates the probability of accidents and survival in the United States. Logistic regression model is used to estimate probability of survival, and censored regression model is used to estimate probability of accidents. The estimation results indicated that the probability of accident and survival are influenced by the physical characteristics of the vehicles involved in the accident, and by the characteristics of the driver and the occupants. Using restrain system and riding in heavy vehicle increased the survival rate. Middle-aged drivers are less susceptible to involve in an accident, and surprisingly, female drivers are more likely to have an accident than male drivers. Riding in powerful vehicles (high horsepower) and driving late night increase the probability of accident. Overall, the driving behavior and characteristics of vehicle does matter and affects the probabilities of having a fatal accident for different types of vehicles.

Accidents, Traffic↗

PubMed2006

Tanshinone IIA inhibits LPS-induced NF-kappaB activation in RAW 264.7 cells: possible involvement of the NIK-IKK, ERK1/2, p38 and JNK pathways.

Nuclear factor kappaB (NF-kappaB) activation by NF-kappaB-inducing kinase (NIK)-IkappaB alpha kinase (IKK) pathway and mitogen-activated protein kinases (MAPKs) pathway are important in inflammation. We recently found that the tanshinone IIA, a diterpene isolated from Salvia miltiorrhiza (S. miltiorrhiza), reduced the production of pro-inflammatory mediators in RAW 264.7 cells stimulated with lipopolysaccharide (LPS). However, little is known about the inhibitory mechanisms of tanshinone IIA on the production of pro-inflammatory mediators. To investigate the inhibitory mechanism, we determined the inhibitory effects of tanshinone IIA on the activation of NF-kappaB and IkappaB alpha phosphorylation, and also examined phosphorylation of NIK and IKK as well as the activation of MAPKs such as p38 MAPK (p38), extracellular signal-regulated kinases 1/2 (ERK1/2), and c-Jun N-terminal kinase (JNK) in RAW 264.7 cells stimulated with LPS. Tanshinone IIA inhibited NF-kappaB-DNA complex, NF-kappaB binding activity, and the phosphorylation of IkappaB alpha in a dose dependent manner. Tanshinone IIA also inhibited the translocation of NF-kappaB from cytosol to nucleus. Moreover, the phosphorylation of NIK and IKK as well as the phosphorylation of p38, ERK1/2, and JNK in the LPS-stimulated RAW 264.7 cells were suppressed by the tanshinone IIA in a dose dependent manner. These results suggest that tanshinone IIA may inhibit LPS-induced IkappaB alpha degradation and NF-kappaB activation via suppression of the NIK-IKK pathway as well as the MAPKs (p38, ERK1/2, and JNK) pathway in RAW 264.7 cells and these properties may provide a potential mechanism that explains the anti-inflammatory activity of tanshinone IIA.

Abietanes↗

PubMed2006

Applicability of interrupter resistance measurements for evaluation of exercise-induced bronchoconstriction in children.

The interrupter technique is a noninvasive method for measuring air-flow resistance during tidal breathing. This method requires minimal cooperation, and is therefore promising for use in uncooperative children. The aim of this study was to evaluate applicability interrupter resistance (Rint) measurements in the assessment of exercise-induced bronchoconstriction (EIB). Fifty children aged 5-12 years with mild to moderate asthma were tested by exercise challenge, consisting of free outdoor running for 6 min at 80-90% of maximal predicted heart rate for age. Rint, forced expiratory volume in 1 sec (FEV1), and peak expiratory flow (PEF) were measured before and 10 min after exercise. EIB was defined as a fall of 10% or more in FEV1 after exercise. The repeatability of Rint was assessed, and its response to exercise challenge was compared with current standardized methods. The mean intermeasurement coefficient of variation was 4.6% (SD, +/- 3.0%), and the repeatability coefficient was 0.056 kPa/l/sec. Eighteen (36%) of the 50 children had EIB after exercise challenge test. The area under the receiver-operating characteristic (ROC) curve was 0.953 (95% confidence interval, 0.853-0.992; P < 0.001), and the optimal Rint cutoff value was 15.2%, producing a sensitivity of 88.9% and a specificity of 96.9%. The positive and negative predictive values were 94.1% and 93.9%, respectively. The kappa value between FEV1 and Rint was 0.83. The repeatability of Rint measurements was good, and the results of exercise challenge tests using Rint measurements have excellent agreement with the current standardized methods to detect EIB. Considering that only minimal comprehension and coordination are needed without forced breathing technique, the Rint measurement can provide a useful alternative for assessment of EIB in children unable to perform reliable spirometry.

Airway Resistance↗

PubMed2006

Hyperostosis may affect prognosis after primary endoscopic sinus surgery for chronic rhinosinusitis.

OBJECTIVE: To investigate the independent effect of hyperostosis on outcome after endoscopic sinus surgery (ESS) in patients with chronic rhinosinusitis (CRS). STUDY DESIGN AND SETTING: The medical records of 81 consecutive patients who had undergone primary ESS for CRS were reviewed retrospectively. Sinus CT scans were evaluated for the presence of hyperostosis to investigate the association with postoperative outcomes. The independent effect of hyperostosis on surgical outcome was analyzed, controlling for possible confounding factors with a multiple logistic regression model. RESULTS: Sixty percent of the patients showed hyperostosis, and there was a statistically significant association between the hyperostosis and postoperative outcome (P = 0.035, chi(2) test), which was confirmed after adjustment for the possible confounding factors (P = 0.048, odds ratio [OR] = 3.19, logistic regression analysis). CONCLUSIONS: Our study suggests that patients with CRS who have hyperostosis may have a poorer surgical outcome than those without hyperostosis. EBM RATING: B-2b.

Adult↗

PubMed2006

Formation of lambda-DNA's in parallel- and crossed-line arrays by molecular combing and scanning-probe lithography.

With the combination of a molecular combing technique and scanning-probe lithographic patterning, lambda-DNA's were stretched and aligned to form line array structures on patterned organic monolayer surfaces. The pattern was generated by anodizing a silicon surface using scanning-probe lithography to implant a polar organic layer in the middle of a nonpolar layer. The molecule in the polar layer, (aminopropyl)triethoxysilane (APS), has a -NH(3)(+) terminal group, which interacts strongly with phosphate backbone of DNA and provides a site for selective attachment of DNA. When parallel lines of APS were patterned, followed by combing along the lines, a single DNA was attached from the very top of each line and stretched along the line all the way to the bottom. The DNA-APS interaction was strong enough to withstand the second combing applied perpendicular to the first one. Thereby, the crossed-line array of DNA's was formed on the crossed-line array pattern of APS on a silicon substrate.

DNA↗

PubMed2006

Expression of acidic fibroblast growth factor and basic fibroblast growth factor in nasal polyps.

CONCLUSION: Up-regulated expression of acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) in nasal polyps may be related to epithelial proliferation and neoangiogenesis associated with nasal polyp growth. BACKGROUND AND OBJECTIVES: aFGF and bFGF are polypeptides that effect mitogenesis, neoangiogenesis and tissue repair. The purpose of this study was to investigate the expression of aFGF and bFGF at both the mRNA and protein levels in nasal polyps. MATERIALS AND METHODS: Tissue samples of nasal polyp and inferior turbinate mucosae were obtained. Reverse transcriptase (RT)-PCR, in situ hybridization, and Western blotting for aFGF and bFGF were performed in nasal polyp and nasal inferior turbinate. RESULTS: RT-PCR showed 50% aFGF and 29% bFGF expression positivity in 14 nasal polyps; however, 13 turbinates revealed no PCR products. aFGF and bFGF expression was localized to some inflammatory cells of nasal polyps by in situ hybridization. Western blotting identified aFGF and bFGF molecular masses of 18 kDa and 24 kDa, respectively, in nasal polyps, and these levels were higher than those observed in nasal turbinates. aFGF and bFGF proteins were also localized in some inflammatory cells of nasal polyps by immunostaining.

Base Sequence↗

PubMed2006

Analysis of gene expression profiles in cholesteatoma using oligonucleotide microarray.

CONCLUSION: Microarray analysis may be a useful tool to identify some candidate genes related to the pathogenesis of cholesteatoma. OBJECTIVE: The aim of this study was to investigate gene expression profiles in human cholesteatoma using an oligonucleotide chip including 10,115 genes. MATERIALS AND METHODS: Gene expression from five cholesteatoma matrices and five normal retroauricular skins was analyzed by Macrogen human oligo-chip and the expression levels of some selected genes were also confirmed by RT-PCR. RESULTS: In all, 1327 up-regulated or 767 down-regulated genes that were over 3 times more prominent in cholesteatoma than in skin were identified by 5 samples of microarray data. Among these up-regulated or down-regulated genes in cholesteatoma, 291 genes were identified in 3 samples or more out of 5 samples as up-regulated expression more than threefold in density and 191 genes were down-regulated more than threefold in density. RT-PCR of 21 selected genes revealed that those expression levels were higher in choleasteatoma than retroauricular skin.

Cholesteatoma, Middle Ear↗

PubMed2006

Outbreak of late-onset group B streptococcal infections in healthy newborn infants after discharge from a maternity hospital: a case report.

During a four-week period, four healthy term newborn infants born at a regional maternity hospital in Korea developed late-onset neonatal group B Streptococcus (GBS) infections, after being discharged from the same nursery. More than 10 days after their discharge, all of the infants developed fever, lethargy, and poor feeding behavior, and were subsequently admitted to the Korea University Medical Center, Ansan Hospital. GBS was isolated from the blood cultures of three babies; furthermore, GBS was isolated from 2 cerebral spinal fluid cultures. Three babies had meningitis, and GBS was isolated from their cerebral spinal fluid cultures. This outbreak was believed to reflect delayed infection after early colonization, originating from nosocomial sources within the hospital environment. This report underlines the necessity for Korean obstetricians and pediatricians to be aware of the risk of nosocomial transmissions of GBS infection in the delivery room and/or the nursery.

Cross Infection↗

PubMed2005

Highly antiproliferative, low-calcemic, side-chain ketone analogs of the hormone 1alpha,25-dihydroxyvitamin D3.

A series 2a-4b of seven new side-chain ketone analogs of calcitriol (1) have been prepared. Unexpectedly, several of these 24- and 25-tert-butyl ketones, even though lacking the classical side-chain tertiary hydroxyl group, are considerably more antiproliferative in vitro than the hormone calcitriol (1) even at physiologically relevant low nanomolar concentrations and are less calcemic than calcitriol (1) in vivo. In addition, ketone analog 19-nor-2a is not significantly less calcemic in vivo than 19-methylene analog 2a.

Animals↗

PubMed2005

Novel A-ring analogs of the hormone 1alpha,25-dihydroxyvitamin D3: synthesis and preliminary biological evaluation.

Prepared from a commercial prostaglandin building block, novel vitamin D3 analogs with a contracted five-membered A-ring were designed and synthesized to mimic the A-ring diol structure of the natural hormone 1alpha,25-dihydroxyvitamin D3. Prepared from commercial 1,4-cyclohexanedione, a structurally simplified analog was designed and synthesized in which a suitably oriented primary allylic hydroxyl group at the C-2 position might be a surrogate for the biologically important 1alpha-OH in the natural hormone.

Animals↗

PubMed2005

Agonist of peroxisome proliferator-activated receptor-gamma, rosiglitazone, reduces renal injury and dysfunction in a murine sepsis model.

BACKGROUND: Agonists of the peroxisome proliferator-activated receptor-gamma may help to regulate inflammation by modulating the production of inflammatory mediators and adhesion molecules. The purpose of this study was to determine the protective effects of rosiglitazone on renal injury in a sepsis model and to explore the mechanism. METHODS: In lipopolysaccharide (LPS)-induced mouse sepsis, we examined the effect of rosiglitazone on LPS-induced overproduction of inflammatory mediators, on the expression of adhesion molecules in renal tubular epithelial cells and on renal function. The mechanism of the protective effect was investigated in vitro using human renal tubular epithelial cells. RESULTS: Rosiglitazone significantly decreased serum tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels during sepsis. The levels of blood urea nitrogen and creatinine were significantly lower in mice pre-treated with rosiglitazone than that in LPS-treated mice. Rosiglitazone reduced the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tubular epithelial cells and interstitium of LPS-treated mice. Pre-treatment with rosiglitazone reduced the infiltration of macrophages/monocytes in renal tissue. In cultured tubular epithelial cells, rosiglitazone significantly decreased the expression of ICAM-1 and VCAM-1 induced by TNF-alpha or IL-1beta, inhibited the degradation of inhibitor kappaBalpha (IkappaBalpha) and blocked the activation of the p65 subunit of nuclear factor (NF)-kappaB. CONCLUSIONS: These results indicate that pre-treatment with rosiglitazone attenuated the production of TNF-alpha and IL-1beta and reduced adhesion molecule expression in renal tubular epithelial cells of LPS-treated mice. Rosiglitazone has an anti-inflammatory effect in renal tubular epithelial cells through the inhibition of NF-kappaB activation.

Animals↗

PubMed2005

Effect of recombinant vascular endothelial growth factor on experimental otitis media with effusion.

CONCLUSION: This study demonstrates that rVEGF in the middle ear cavity contributes significantly to the development of OME by increasing the vascular permeability of the middle ear mucosa. OBJECTIVE: Vascular endothelial growth factor (VEGF) has been detected in otitis media with effusion (OME). It has a very strong effect on increasing vascular permeability, and is much more potent than platelet-activating factor, arachidonic acid metabolites or histamine. The purpose of this study was to investigate whether recombinant VEGF (rVEGF) can increase vascular permeability in the middle ear mucosa of rats. MATERIAL AND METHODS: rVEGF was injected transtympanically at doses of 0.01, 0.1 and 1.0 microg in the experimental groups; normal saline was injected in the control group. Twenty-four h after the injection of rVEGF, middle ear fluid was aspirated and the vascular permeability of the middle ear mucosa was measured by means of the Evans Blue vital dye technique. RESULTS: Extravasation of Evans Blue dye was found in all specimens injected with rVEGF, and was quantified using a spectrophotometer. Middle ear fluid developed in all ears injected with 0.1 or 1.0 microg of rVEGF and histopathology of the middle ear mucosa revealed severe inflammatory cellular infiltration, subepithelial edema and vascular dilatation. Rats injected with 1.0 microg of rVEGF showed a significant increase in middle ear vascular permeability in comparison with the control group (p < 0.05).

Animals↗

PubMed2005

Zygomaticomandibularis muscle.

The aim of this study was to elucidate the precise anatomy of the zygomaticomandibularis muscle through cadaveric dissection and magnetic resonance imaging (MRI). Five fresh human cadavers and 10 fixed cadavers were dissected. Nine preserved human cadavers were used for the MRI study. Four volunteers took MRIs of their head as well. Zygomaticomandibularis muscle was found in all the cadaveric specimens. It is a fan shaped muscle. The length of the muscle is 25.1 +/- 4.6 mm, and the width at the zygomatic arch is 16.6 +/- 4.2 mm. The thickness is approximately 4.8 +/- 1.9 mm. It originates from the deep layer of the deep temporal fascia approximately 1 cm above the zygomatic arch and is inserted into the superior border and outer surface of the mandible between the coronoid process and mandibular notch. The deepest layer of the masseter muscle covers the lateral surface of zygomaticomandibularis. We believe that this muscle functions as coordinator of the temporalis and masseter in mammals with strong masticatory power but is a degraded or rudimentary muscle in humans.

Cadaver↗

PubMed2004

Serum high sensitivity C-reactive protein is associated with carotid intima-media thickness in type 2 diabetes.

BACKGROUND: High sensitivity C-reactive protein (hsCRP) is more sensitive than standard C-reactive protein (CRP) assay in evaluating the risk of coronary heart disease and other atherosclerotic events. By this time, there are several reports that type 2 diabetic subjects have higher serum levels of hsCRP than those of non-diabetic subjects. However, there are few reports about factors which have influence upon the level of serum hsCRP in type 2 diabetic subjects. We had evaluated the association of serum hsCRP level with risk factors of cardiovascular diseases and carotid intima-media thickness (IMT) in type 2 diabetic subjects. METHODS: One hundred and five patients (59 men and 46 women) with type 2 diabetes were recruited. Subjects with severe cardiovascular diseases were excluded. All subjects were undergone carotid ultrasonography for evaluation of carotid IMT. Serum hsCRP concentrations were measured. RESULTS: Serum hsCRP level was correlated with mean left IMT (r = 0.366, P = 0.003), maximal left IMT (r = 0.370, P = 0.002), mean right IMT (r = 0.281, P = 0.023) and maximal right IMT (r = 0.370, P = 0.002), body mass index (r = 0.377, P < 0.001), waist circumference (r = 0.342, P < 0.001), waist-hip ratio (r = 0.229, P = 0.020), serum total cholesterol (r = 0.202, P = 0.024), serum triglyceride (r = 0.292, P = 0.022) and serum low-density lipoprotein (r = 0.133, P = 0.044). CONCLUSION: Our result shows that serum hsCRP level is correlated with carotid IMT and the risk factors of cardiovascular diseases and may be useful to predict accelerated atherosclerotic process in type 2 diabetic subjects.

Adult↗

PubMed2003

Association between glutathione S-transferase M1 and T1 polymorphisms and increased risk for bladder cancer in Korean smokers.

We evaluated the relationship between polymorphisms in the GSTM1 and GSTT1 genes and smoking status in a case-controlled study of a Korean population. The GSTM1 and GSTT1 genotypes were determined using a polymerase chain reaction (PCR)-based method and prognostic factors, such as staging and grading were evaluated for 126 bladder cancer patients, and 204 control subjects. Smoking represented a high-risk factor (odds ratio (OR)=4.8, 95% confidence interval (CI)=2.9-8.0) for the patients with bladder cancer. The frequency of GSTM1 null individuals was higher than in the controls, but the differences were not statistically significant (OR=1.56, 95% CI=2.9-8.0). For Korean subjects who smoked more than 1 pack of cigarettes per year (PPY), the increased risk of bladder cancer was associated with the GSTM1 null genotype (OR=0.5, 95% CI=0.3-0.9). Low-stage bladder tumors were more common among the GSTM1 null genotypes (OR=2.3; 95% CI=1.1-5.5). This study suggests that in Korean subjects the GSTM1 null genotype may be associated with increased risk for bladder cancer, in a manner that appears to depend upon smoking status. And also, in bladder cancer patients the GSTM1 null genotype appears to be associated with a poorer prognosis with low stage bladder tumors.

Case-Control Studies↗

PubMed2003

Routes to metallodendrimers: synthesis of isomeric neutral metallomacromolecules based on bis(2,2':6',2"-terpyridine)ruthenium(II) connectivity.

Routes for the syntheses of isomeric, zwitterionic, bisterpyridine-Ru(II)-based macromolecules are described. Access to these novel architectures is facilitated by the construction of terpyridine-modified, 1-->3 C-branched, ester-terminated building blocks. Constitutional isomers result from the interchangable placement of methyl and tert-butyl ester groups on both the branched framework near the Ru(II) centers and the termini of the branched construct. Water solubility is imparted to each isomer through selective transformation of the tert-butyl esters to their corresponding carboxylates. Along with the standard characterization techniques, electrochemical and spectroscopic data also support the structural formation.

Journal Article↗

PubMed2003

Lipase mediated chiral resolution of 4-arylthio-2-butanol as an intermediate for beta-lactam antibiotics.

This paper deals with chiral enzymatic resolution of 4-arylthio-2-butanols by lipase to prepare potential intermediates of beta-lactam antibiotics. Among several lipases employed, lipase P type enzyme gave the highest ee value to prepare (R)-4-arylthio-2-butyl acetate. The enzymatic resolution of phenyl substituted alcohol (6a) using lipase P showed the highest ee value (99.7%) among those of 4-arylthio-2-butanol derivatives. Lipase P mediated hydrolysis of acylester 7a gave also (R)-alcohol 6a selectively. For determination of enantiomeric purity of these enzymatic resolved analytes, liquid chromatographic analysis was performed using two coupled Chiralcel OD and (R,R)-WhelkO chiral column.

Butanols↗

PubMed2003

Activation of nitric oxide-cyclic guanosine monophosphate signaling in kidney by extracorporeal shock wave therapy.

PURPOSE: We defined whether extracorporeal shock wave therapy (ESWT) to the kidney activates the nitric oxide (NO)-cyclic 3',5'-guanosine monophosphate (cGMP) pathway. MATERIALS AND METHODS: A total of 90 male rabbits were randomly divided into group 1--pretreated with normal saline, group 2--pretreated intravenously (i.v.) with Nomega nitro-L-arginine-methyl ester (NAME) (100 mg/kg), group 3--pretreated i.v. with NAME and L-arginine (300 mg/kg) with ESWT to 1 kidney, group 4--pretreated IV with ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) (20 microg/kg) and group 5--pretreated with normal saline with ESWT to the bladder. Plasma nitrite, NO metabolite and cGMP were analyzed in peripheral blood samples before, immediately after, and 30 and 60 minutes after ESWT. RESULTS: ESWT to the kidney but not to the bladder caused an increase before, immediately after, and 30 and 60 minutes after ESWT in plasma nitrite in group 1 (186.1 +/- 20.6, 217.5 +/- 21.6, 241.9 +/- 28.4 and 230.5 +/- 25.3 nM) and group 5 (149.0 +/- 14.7, 155.6 +/- 18.4, 131.8 +/- 13.6 and 140.0 +/- 15.7 nM), and in cGMP in group 1 (24.2 +/- 1.9, 33.8 +/- 3.2, 32.9 +/- 2.2 and 29.4 +/- 1.9 pmol/ml) and group 5 (25.5 +/- 2.1, 27.5 +/- 2.5, 28.7 +/- 3.1 and 25.5 +/- 2.6 pmol/ml, respectively). In group 2 NAME significantly inhibited the production of nitrite (113.4 +/- 18.6, 118.2 +/- 19.9, 114.6 +/- 18.3 and 112.5 +/- 17.6 nM) and cGMP (19.4 +/- 2.6, 20.6 +/- 2.8, 19.3 +/- 2.7 and 18.6 +/- 2.6 pmol, respectively). In group 3 inhibited nitrite and cGMP production caused by NAME was recovered with L-arginine. In group 4 ODQ significantly inhibited cGMP production. CONCLUSIONS: The results show that ESWT increases the level of NO and cGMP released by the kidney in an animal model.

Animals↗