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Biomedical subjects

C H Kim

Publications and source records attributed to C H Kim.

At least 19 recordsLinked to original sources

Hydrogen peroxide-producing Lactobacilli in the vaginal flora of pregnant women with preterm labor with intact membranes.

OBJECTIVES: To investigate the role of vaginal infection in preterm delivery, we studied characteristics of vaginal discharge related to hydrogen peroxide-producing Lactobacilli. METHODS: Vaginal specimens were obtained from 66 women with normal pregnancy and 30 women with preterm labor with intact membranes. pH, leukocyte counts on wet smear, and scores by Nugent criteria on Gram stain were measured. Lactobacilli were tested for their production of hydrogen peroxide. RESULTS: Leukocyte levels in wet smears and Nugent scores of Gram-stained smear of women with preterm labor with intact membranes were significantly higher than those of normal pregnant women (P<0.01, P<0.05). Hydrogen peroxide-producing Lactobacilli levels in the vaginal flora of women with preterm labor with intact membranes were significantly lower (P<0.01). CONCLUSION: Distribution of hydrogen peroxide-producing Lactobacilli in vaginal flora as defense factors for infection may have an important role in the pathophysiology of preterm labor.

Adult↗

Rare cases of Ménière's disease in children.

Classical Ménière's disease is rarely found in children and literature regarding it is scarce. In general, the frequency of Ménière's disease in children is only 0.4-7.0 per cent of that in adults. The progression pattern of Ménière's disease in children is not known well. Here, we report three cases of Ménière's disease in children less than 15 years old, treated over nine years. The three cases comprise 14- and 13-year-old boys and a nine-year-old girl. Two of the three patients initially complained only of recurrent bouts of vertigo, without any tinnitus, ear fullness or hearing impairment. In all three cases, the early pure tone audiograms showed only high tone frequency loss, regardless of subjective hearing loss, and the decrease in the hearing threshold was observed one to eight years after the dizziness attacks began. The hearing threshold was usually decreased to a level of mild or moderate hearing impairment. After diuretic treatment, vertigo was generally well controlled, and some cases showed improvement in hearing. Of the total number of patients with Ménière's disease who visited our department over nine years, 2.6 per cent (3/114) were children, and the overall incidence of Ménière's disease in children with vertigo was 2.0 per cent (3/147). In conclusion, Ménière's disease in children rarely develops and may have characteristics of high tone loss in initial audiograms.

Adolescent↗

Detection of infectious haematopoietic necrosis virus and infectious salmon anaemia virus by molecular padlock amplification.

A new method for the molecular detection of the fish pathogens, infectious haematopoietic necrosis virus (IHNV) and infectious salmon anaemia virus (ISAV), is described. By employing molecular padlock probe (MPP) technology combined with rolling circle amplification (RCA) and hyperbranching (Hbr), it is possible to detect RNA target sequence from these viruses at levels comparable with those detected by the polymerase chain reaction (PCR), but without prior reverse transcription. The use of MPP technology combined with RCA and Hbr for the detection of IHNV and ISAV in fish exhibited selectivity comparable with that of PCR while potentially reducing the time and cost required for analysis. The method described was used to detect as few as 10(4) DNA oligonucleotide targets and was sequence-specific at the single base level. Viral RNA could be detected directly, either alone or in the presence of non-viral RNA from fish tissue. This technology is applicable for detecting a variety of microbes, in addition to IHNV and ISAV, and is ideal for further integration into a biosensor platform for on-site diagnosis of pathogen infection in fish.

Animals↗

Pulmonary tuberculosis in young Korean soldiers: incidence, drug resistance and treatment outcomes.

OBJECTIVE: To determine the incidence and treatment outcomes of pulmonary tuberculosis (PTB) in young soldiers of South Korea. DESIGN: From 2000 to 2004, all soldiers with a new diagnosis of tuberculosis (TB) were enrolled in the study, based on the official records of the Armed Forces Medical Command. The demographic and clinical data of the cases were evaluated retrospectively. RESULTS: A total of 3115 TB cases were reported during the study period, of whom 2071 (66.5%) were reported as PTB. The annual incidence rates of PTB were 96.4 per 100,000 population in 2000, 89.3 in 2001, 67.6 in 2002, 60.2 in 2003, and 63.1 in 2004. A total of 270 patients diagnosed and treated at the Armed Forces Capital Hospital were analysed. Of the Mycobacterium tuberculosis isolates, 87.4% were susceptible to all available anti-tuberculosis drugs; 253 (93.7%) patients eventually completed initial anti-tuberculosis treatment. Among the patients with smear-positive PTB, the cure rate was 89.3% (100/112). CONCLUSION: Our results demonstrate that the incidence of PTB in Korean soldiers, although still high, was declining steadily. With good case management, the overall success rate of initial treatment was approximately 90%.

Adult↗

Concurrent chemoradiotherapy in patients with nasopharyngeal cancer: prognostic significance of low expression of bax.

A randomized trial has demonstrated that concurrent chemoradiotherapy (CRT) is superior to radiotherapy (RT) alone in locally advanced nasopharyngeal cancer (NPC). Our study comprise 35 patients with locally advanced NPC (stage I: 1, II: 12, III: 7, IV: 15) with 1 cycle of induction chemotherapy (5-fluorouracil 1,000 mg/m(2)/day and cisplatin 20 mg/m(2)/day, days 1- 4) followed by concurrent CRT starting on day 22. Concurrent CRT consisted of RT (70 Gy/35 fractions for 7 weeks) with cisplatin 20 mg/m(2)/day for 4 days on weeks 1, 4, 7 of RT. Complete response (CR) was achieved in 33 patients (94%). Four-year progression-free survival (PFS) and overall survival (OS) of all patients were 57% and 65%, respectively. In analysis of prognostic factors, low expression of bax was the most significant independent predictor of poor prognosis in both PFS (p=0.002) and OS (p=0.008). In conclusion, the outcome of patients treated with this combined therapeutical modality appears to be comparable with that of Intergroup 0099 trial with high CR rate. Low expression of bax was significantly associated with poor PFS and OS.

Adult↗

The role of TST in the diagnosis of latent tuberculosis infection among military personnel in South Korea.

BACKGROUND: The rapid and accurate diagnosis of latent tuberculosis infection (LTBI) is crucial in military settings because military personnel live in crowded circumstances and are of an age group with a high incidence of tuberculosis (TB). We tried to elucidate whether the tuberculin skin test (TST) accurately reflects the risk of TB infection among military personnel, in a setting of intermediate TB prevalence and where bacille Calmette-Guérin (BCG) vaccination is mandatory. METHODS: A multi-stage cluster survey was conducted among military personnel in South Korea. Participants were grouped according to their risk of TB infection: Group 1, no identifiable risk of TB; Groups 2 and 3, recent casual (Group 2) or close (Group 3) contact with smear-positive TB patients. RESULTS: Of 1045 participants, 857 (82.0%) had been BCG-vaccinated. The odds ratio (OR) of a positive TST (10 mm cut-off) for Group 2 (n = 184) and Group 3 (n = 83) compared with Group 1 (n = 778) were 0.95 (95%CI 0.67-1.38) and 1.7 (95%CI 1.06-2.70), respectively (P value for trend 0.16). CONCLUSIONS: The TST does not accurately reflect the risk of LTBI among young military personnel in a setting where there is intermediate TB prevalence and extensive BCG coverage.

Adult↗

Spectral studies of SnO2 nanofibres prepared by electrospinning method.

Tin oxide nanofibres with 100-150 nm diameter has been prepared, for the first time by calcination of poly(vinyl acetate) (PVAc)/SnO2 composite fibres prepared by electrospinning method as precursor. Scanning electron microscopic images revealed cylindrical morphology of the fibres after calcination at 600 degrees C. Both, X-ray diffraction (XRD) and Raman spectral data confirmed the presence of phase pure tetragonal rutile tin oxide after calcination process. Room temperature photoluminescence (PL) spectra of tin oxide nanofibres under excitation at 325 nm wavelength show a strong green emission at 525 nm with a band gap of 2.41 eV. FT-IR spectra confirmed the formation of pure tin oxide after calcination at 600 degrees C and complete removal of PVAc during calcination. UV-vis spectrum of the fibres showed absorption at 315 nm due to the direct electron transfer in tin oxide.

Crystallization↗

Molecular cloning of levan fructotransferase gene from Arthrobacter ureafaciens K2032 and its expression in Escherichia coli for the production of difructose dianhydride IV.

AIMS: To clone and overexpress a novel levan fructotransferase gene lftA from Arthrobacter ureafaciens K2032. METHODS AND RESULTS: The lftA gene, encoding a levan fructotransferase (LFTase) of 521 amino acids (aa) residues, was cloned from the genomic DNA of A. ureafaciens K2032, and overexpressed in Escherichia coli. The recombinant LFTase overexpressed in E. coli was then used to produce a difructose dianhydride (DFA IV) from levan. DFA IV crystals with 97% purity could be obtained from the reaction mixture in 83.7% yield by using a natural crystallization method. CONCLUSIONS: The lftA gene cloned from A. ureafaciens K2032 encode a novel levan fructotransferase which produces difructose dianhydride (DFA IV) from levan. SIGNIFICANCE AND IMPACT OF THE STUDY: Levan fructotransferase is a useful enzyme with great promise in the production of DFA IV and various fructosides.

Amino Acid Sequence↗

Morphology and kinetics studies on cephalosporin C production by Cephalosporium acremonium M25 in a 30-l bioreactor using a mixture of inocula.

AIMS: In this study, the relationship between morphology and cephalosporin C (CPC) production in a 30-l bioreactor culture of Cephalosporium acremonium M25 using a 3:7 seed mixture was investigated. In addition, the kinetic model was established and applied. METHODS AND RESULTS: CPC production was performed in a 30-l bioreactor using a 3:7 seed mixture. It was recognized that a 3:7 seed mixture was able to reduce lag phase and enhance CPC production. The maximum CPC production and cell mass were 1.96 and 81.5 g l-1 respectively. Through a morphology study by observation using image analysis, it was concluded that changes of morphological features predicted the progressive production of CPC and that a morphology study could be useful in monitoring the CPC fermentation by C. acremonium M25. In the kinetics study, a kinetic model of CPC fermentation was developed and applied. The proposed model could adequately describe the fermentation of C. acremonium M25 in a 30-l bioreactor. CONCLUSIONS: CPC productivity was improved by using a 3:7 seed mixture in a 30-1 bioreactor. The changes in morphological features showed a very similar tendency with CPC production. A kinetic model of CPC fermentation was successfully established. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of the present study suggest that the use of a 3:7 seed mixture inocula has considerable possibilities for improving CPC productivity if applied to industrial scale fermentations. Through morphology and kinetics study, the kinetic model to describe the morphological differentiation and CPC production by C. acremonium M25 was established.

Acremonium↗

A simple and rapid chromatographic strip test for detection of antibody to porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) continues to be a major economic problem for swine industries worldwide despite several disease-reduction strategies such as age-segregated early weaning and all-in-all-out pig movement. Routine diagnosis of PRRSV is carried out by the combined use of an antibody-detecting enzyme-linked immunosorbent assay (ELISA), immunofluorescence, reverse transcription-polymerase chain reaction, and virus isolation. These assays require specialized laboratory equipment in addition to multistep sample handling and sample preparation. The objective of this study was to evaluate a simple pen-side assay (BioSign PRRSV) for rapid detection of PRRSV antibody based on a lateral flow chromatographic strip immunoassay system. This assay uses Escherichia coli-expressed viral nucleocapsid protein antigen for detecting antibodies against PRRSV in swine sera. In this report, the authors describe the evaluation of this assay using sera from both clinical samples and experimentally infected piglets. The results were compared with those of a standard, commercially available antibody ELISA (HerdChek PRRS ELISA) and an indirect immunofluorescence assay using the same serum samples. The BioSign PRRSV assay was capable of detecting antibodies in sera known to contain antibodies to PRRSV, resulting in 93.2% sensitivity for samples from experimentally infected pigs and 98.7% sensitivity for clinical serum samples. For sera that did not contain antibodies to PRRSV, the specificity was found to be 98.5% and 99.2% for clinical and experimental serum samples, respectively.

Animals↗

Studies involving the GH-IGF axis: Lessons from IGF-I and IGF-I receptor gene targeting mouse models.

The IGFs are ubiquitous and have pleoitropic effects. They are critical for normal growth and development, and for normal functioning of adult tissues. A liver-specific gene-deletion knockout of the IGF-I gene resulted in a mouse model with reduced circulating IGF-I levels, that led to insulin resistance due to the secondary elevation of circulating GH levels. The reduction in circulating IGF-I levels was also associated with a reduction in cancer growth and metastases in three cancer models, one for colon cancer and two for breast cancer. A second mouse model, using the transgenic approach, inhibited the IGF-I and insulin receptor function in skeletal muscle, and resulted in severe insulin resistance in muscle followed by insulin resistance in fat and liver and, eventually, beta-cell dysfunction and development of Type 2 diabetes. This progression from insulin resistance to Type 2 diabetes was most likely due to lipotoxicity with elevated serum and tissue triglyceride levels. Evidence supporting the hypothesis came from the use of fibrates and leptin injections, each of which enhanced fatty acid (FA) oxidation in liver and muscle and was associated with a reversal of the insulin resistance and diabetes.

Animals↗

HMG-CoA reductase inhibition reverses LCAT and LDL receptor deficiencies and improves HDL in rats with chronic renal failure.

Dyslipidemia is a prominent feature of chronic renal failure (CRF) and a major risk factor for atherosclerosis and the progression of renal disease. CRF-induced dyslipidemia is marked by hypertriglyceridemia and a shift in plasma cholesterol from HDL to the ApoB-containing lipoproteins. Several studies have demonstrated a favorable response to administration of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors (statins) in CRF. This study was intended to explore the effect of statin therapy on key enzymes and receptors involved in cholesterol metabolism. Accordingly, CRF (5/6 nephrectomized) and sham-operated rats were randomized to untreated and statin-treated (rosuvastatin 20 mg x kg(-1) x day(-1)) groups and observed for 6 wk. The untreated CRF rats exhibited increased total cholesterol-to-HDL cholesterol ratio, diminished plasma lecithin:cholesterol acyltransferase (LCAT) and the hepatic LDL receptor, elevated hepatic acyl-CoA:cholesterol acyltransferase (ACAT), and no change in hepatic HMG-CoA reductase, cholesterol 7alpha-hydroxylase, or HDL receptor (SRB-1). Statin administration lowered HMG-CoA reductase activity, normalized plasma LCAT, total cholesterol-to-HDL cholesterol ratio, and hepatic LDL receptor but did not significantly change either plasma total cholesterol, hepatic cholesterol 7alpha-hydroxylase, total ACAT activity, or SRB-1 in the CRF animals. Statin administration to the normal control rats led to significant increases in plasma LCAT and hepatic LDL receptor, significant reductions of total cholesterol-to-HDL cholesterol ratio, hepatic HMG-CoA reductase activity, and cholesterol 7alpha-hydroxylase abundance with virtually no change in plasma cholesterol concentration. Thus administration of rosuvastatin reversed LCAT and LDL receptor deficiencies and promoted a shift in plasma cholesterol from ApoB-containing lipoproteins to HDL in CRF rats.

Animals↗

Delayed bleeding after gamma knife surgery for meningioma.

We report the occurrence of haemorrhage in a meningioma after gamma knife surgery.A 52-year-old woman had undergone gamma knife radiosurgery for a growing meningioma in the left tentorial hiatus three years earlier (A radiation dose of 15 Gy was administered to the margin, with a maximum dose of 30 Gy, Fig. 1a). The size of the mass decreased steadily, and central lucency was seen in the follow-up magnetic resonance images, a usual finding seen after gamma knife surgery (MRI, Fig. 1b). However, a MRI taken at the 30-month follow-up showed the tumour to be swollen, and peritumoural oedema had increased (Fig. 1c). Three years later, apoplectic symptoms occurred, and computed tomography revealed a peritumoural haemorrhage, with oedema (Fig. 1d). An emergency craniotomy was carried out, and the biopsy showed a transitional type of meningioma, with vasculopathy and necrosis. After operation she had a right hemiparesis and a visual defect.

Female↗

Downregulation of hepatic acyl-CoA:diglycerol acyltransferase in chronic renal failure.

Chronic renal failure (CRF) is associated with hypertriglyceridemia and elevated plasma VLDL and IDL concentrations. These events can be due to either increased production or depressed catabolism of triglyceride-rich lipoproteins. Several studies have documented downregulation of lipoprotein lipase, hepatic triglyceride lipase, and the VLDL receptor, leading to depressed clearance and elevated plasma concentration of triglyceride-rich lipoproteins and their remnants in CRF. However, the effect of CRF on the triglyceride biosynthetic pathway has not been explored. Diglycerol acyltransferase (DGAT) is a microsomal enzyme that joins acyl-CoA to 1,2 diacylglycerol and, as such, constitutes the final step in triglyceride biosynthesis. Two distinct forms of DGAT (DGAT-1 and -2) have thus far been identified. The present study was undertaken to examine the effect of CRF on DGAT gene expression and activity in the liver, which is the source of endogenous triglycerides in the circulation. Male Sprague-Dawley rats were studied 8 wk after 5/6 nephrectomy (CRF) or sham operation. DGAT-1 and DGAT-2 mRNA abundance and DGAT activity were quantified. The CRF group showed reduced creatinine clearance, elevated plasma triglycerides, and VLDL concentrations. This was accompanied by significant reductions in hepatic DGAT-2 mRNA abundance (P < 0.01) and total DGAT activity (P < 0.1), pointing to diminished hepatic triglyceride production capacity in CRF animals. In conclusion, CRF results in significant downregulation of hepatic DGAT gene expression and activity. Given the critical role of DGAT in triglyceride biosynthesis, the present study points to diminished, not increased, hepatic triglyceride synthetic capacity in CRF rats.

Acyltransferases↗

Purification, cDNA cloning and expression of an insect defensin from the great wax moth, Galleria mellonella.

An insect defensin, named Galleria defensin, was purified from the larval haemolymph of Galleria mellonella immunized against E. coli. The peptide was composed of forty-three amino acid residues containing six cysteines that might be engaged in intramolecular disulphide bridges. The primary structure of Galleria defensin shared about 90.7% identity to that of heliomicin, which was an insect defensin isolated from Heliothis virescens. The full-length cDNA encoding Galleria defensin was cloned from the fat body of the immunized G. mellonella larvae. Northern blot analysis revealed that Galleria defensin was expressed not only in the fat body but also in the midgut against invading bacteria into haemocoel. This is the first report presenting cDNA and expression of an insect defensin in the lepidopteran species.

Amino Acid Sequence↗

Cloning and expression of a novel esterase gene cpoA from Burkholderia cepacia.

AIMS: To screen and clone a novel enzyme with specific activity for the resolution of (R)-beta-acetylmercaptoisobutyrate (RAM) from (R,S)-beta-acetylmercaptoisobutyrate [(R,S)-ester]. METHODS AND RESULTS: A micro-organism that produces a novel esterase was isolated and identified as the bacterium Burkholderia cepacia by using the analysis of cellular fatty acids, Biolog automated microbial identification/characterization system, and 16S rRNA gene sequence analysis. A novel esterase gene was cloned from the chromosomal DNA of B. cepacia and was designated as cpoA. The cpoA encodes a polypeptide of 273 amino acids which shows a strong sequence homology with many bacterial nonhaeme chloroperoxidases. In addition, a typical serine-hydrolase motif, Gly-X-Ser-X-Gly, and the highly conserved catalytic triad, Ser95, Asp224, and His253, were identified in the deduced amino acid sequence of cpoA by multiple sequence alignment. CONCLUSION: The cpoA cloned from B. cepacia encodes a novel esterase which is highly related to the nonhaeme chloroperoxidases. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report that describes the isolation and cloning of a serine esterase gene from B. cepacia, which is useful in the chiral resolution of (R,S)-ester. The cloned gene will allow additional research on the bifunctionality of the enzyme with esterase and chloroperoxidase activity at the structural and functional levels.

Amino Acid Sequence↗

Estimation of the incidence of sudden infant death syndrome in Korea: using the capture-recapture method.

This study was undertaken to estimate the incidence of sudden infant death syndrome (SIDS) for 2 years from 1997 to 1998 in Korea. The information on SIDS was obtained from three independent sources, the Korean Medical Insurance Corporation data, data from different medical facilities (Korean surveillance on SIDS) and mortality data from the Korean National Statistical Office. A log linear model with no interactions among the 3 sources was used with the selection criteria of both the Akaike Information Criterion and the Bayesian Information Criterion. The 95% confidence intervals of the estimated number of SIDS deaths were calculated using the goodness-of-fit-method. The estimated number of deaths who were not found in any of the sources was 535, and the estimated total number of SIDS deaths was 759. The 95% confidence interval for estimated total number of patients ranged from 642 to 1522. The estimated rate of SIDS cases was 0.56 per 1000 live births per annum, which is similar to the incidence in the USA or Japan.

Age Distribution↗

Treatment of spent brine from a nitrate exchange process using combined biological denitrification and sulfate precipitation.

A combined biological denitrification and sulfate precipitation process was developed to treat and reuse the spent brine produced by a nitrate exchange system. Although the spent brine contained a relatively high salt concentration, more than 80% of NO3(-)-N fed into the denitrification reactors was removed at a nitrate-N loading rate of 2.2 g NO3(-)-N/l x day, regardless of the presence or absence of sulfate up to 8,000 mg/l. Sulfate present in the spent brine was successfully removed by the addition of BaCl2 and the settling velocity of BaSO4 suspension was remarkably enhanced by FeCl3 coagulation. Since most of the chloride consumed in regenerating the exhausted resins was replaced during chemical treatment with BaCl2 and FeCl3, it was possible to reuse the treated spent brine as a regenerant after compensating for the small amount of unreplaced NaCl.

Bioreactors↗