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Biomedical subjects

J H Cho

Publications and source records attributed to J H Cho.

At least 19 recordsLinked to original sources
PubMed2006

Immunoproteomic analysis of capsulate and non-capsulate strains of Lactococcus garvieae.

A comparative immunoproteomic study was carried out to investigate the immunogenicity of capsulate (KG9408) and non-capsulate (NSS9310) strains of Lactococcus garvieae. Immunoblot assays, following two-dimensional gel electrophoresis (2-DE) for L. garvieae strains, revealed a significant difference between anti-capsulate and anti-non-capsulate rabbit sera with respect to the number and antigenicity of antigenic spots. Anti-capsulate and anti-non-capsulate rabbit sera reacted with an average of 72 and 127 antigenic spots, respectively. The strong reaction of anti-non-capsulate sera with elongation factor (EF)-G and -Tu, and GMP synthase, of the L. garvieae strains identifies these as specific major antigens. This study clearly demonstrates the differences in 2-DE immunoblot profiles between the capsulate and non-capsulate strains of L. garvieae. These differences may be the reason for variations in immunogenicity between capsulate and non-capsulate strains. Glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, arginine deaminase and ornithine carbamoyltransferase were identified from the 2-DE immunoblot profiles of both strains. Therefore, these common antigens are potential markers for the development of vaccines against L. garvieae, irrespective of strain. Immunoproteomics, a powerful tool for studying antigens at the proteomic level, allowed a comparative investigation of the immunogenicity of capsulate and non-capsulate strains of L. garvieae for vaccine development.

Animals↗
PubMed2006

Electrical relaxation of bismuth germanate silicate glasses.

The frequency-dependent electrical data of the bismuth germanate silicate (BGSO) glasses have been discussed in the framework of the electric modulus representation and the power-law conductivity. The activation energies of the mean electric relaxation time and the direct current (dc) conductivity obtained by the complex modulus analysis show that the BGSO glasses satisfy the Barton, Nakajima, and Namikawa (BNN) relation. The proper relation between the exponent of the power-law conductivity and the stretched exponential of the modulus representation is shown. The temperature- and frequency-dependent characteristics of non-Debye behavior are discussed. The scaling properties of both the modulus M*(omega) and the alternating current (ac) conductivity sigma(omega) are examined.

Journal Article↗
PubMed2006

Immunohistochemical localization of glutamate in the gerbil main olfactory bulb using an antiserum directed against glutamate.

Information on the localization and the roles of glutamate in the nervous system is becoming valuable because the axon terminals of the olfactory sensory neurons and the synapses of the mitral and tufted output cells appear to be glutamatergic. In this study, we have analysed the distribution of glutamate immunoreactivity in the main olfactory bulb (MOB) of the Mongolian gerbil using an antiserum directed against glutamate. Glutamate immunoreactivity in the MOB was present in the olfactory nerve layer (Onl), glomerular layer (GL), external plexiform layer (EPL) and mitral cell layer (ML), but not in the granule cell layer (GCL). Glutamate immunoreactivity detected in the Onl was thought to be terminal ramifications of glomeruli. Some neurons in the periglomerular region showed glutamate immunoreactivity. In the EPL, glutamate immunoreactivity was found in some neuronal somata (tufted cells) and processes. In addition, mitral cells in the ML were labelled by the glutamate antibody. The pattern of glutamate immunoreactivity in the mitral cells was similar to that in the tufted cells. In brief, glutamate in the gerbil MOB is the neurotransmitter used by primary afferents and output neurons.

Animals↗
PubMed2006

Growth-inhibiting activity of active component isolated from Terminalia chebula fruits against intestinal bacteria.

The growth-inhibitory activity of materials derived from the fruit of Terminalia chebula was evaluated against six intestinal bacteria by means of an impregnated paper disk agar diffusion method. The butanol fraction of T. chebula extract had profound growth-inhibitory activity at a concentration of 5 mg per disk. The biologically active component isolated from the T. chebula fruits was identified with a variety of spectroscopic analyses as ethanedioic acid. The growth responses varied in accordance with the bacterial strain, chemical, and dosage tested. In a test with concentrations of 2 and 1 mg per disk, ethanedioic acid had strong and moderate inhibitory activity against Clostridium perfringens and Escherichia coli, respectively, with no associated adverse effects on the growth of the four tested lactic acid-producing bacteria. Ellagic acid derived from T. chebula fruits exerted a potent inhibitory effect against C. perfringens and E. coli, but little or no inhibition was observed with treatments of behenic acid, P-caryophyllene, eugenol, isoquercitrin, oleic acid, ca-phellandrene, 3-sitosterol, stearic acid, a-terpinene, terpinen-4-ol, terpinolene, or triacontanoic acid. These results may be an indication of at least one of the pharmacological properties of T. chebula fruits.

Clostridium perfringens↗
PubMed2006

The association between CD99 and LMP-1 expression in nasopharyngeal carcinoma.

AIM: To characterize the roles of LMP-1 and CD99 in nasopharyngeal carcinogenesis, we undertook this pilot study of LMP-1 and CD99 expressions in nasopharyngeal cancer (NPC). MATERIALS AND METHOD: 40 NPC tissue samples were grouped according to the WHO classification. Immunohistochemical studies were performed using monoclonal antibodies against EBV latent membrane protein 1 (LMP-1) and CD99 protein. In addition, CD99 expression was evaluated in 10 samples of non-neoplastic nasopharyngeal epithelium. RESULTS: LMP-1 was detected in 12 of the 40 (30.0%) cases and its expression was found to be confined to epithelial tumor cells. WHO type I NPC samples were completely negative for LMP-1, whereas WHO type III NPC samples showed highest expression. Interestingly, CD99 was expressed in all of the non-neoplastic nasopharyngeal epithelium samples along the cytoplasmic border. CD99 expression was noted in NPC tumor cells (5 of the 40 cases, 12.5%) and in surrounding lymphoid stroma (23 of the 40 cases, 57.5%), but was not expressed in WHO type I NPC. In the 12 LMP-1 positive cases, 9 cases (75.0%) were CD99 negative, and 3 cases (25.5%) were CD99 positive. There was a statistical significance between LMP-1 and CD99 expression in lymphoid stroma. CONCLUSION: Our results suggest that the LMP-1 induced down-regulation of the CD99 pathway is important in nasopharyngeal carcinogenesis, and that the expression of CD99 in lymphoid stroma may regulate immune response to NPC.

12E7 Antigen↗
PubMed2005

Acinic cell carcinoma on the lower lip resembling a mucocele.

A 64-year-old woman presented with a 2-week history of an asymptomatic mass involving the lower lip. Histopathological examination showed a well-circumscribed tumour composed of many lobules separated by thin, fibrous connective tissue. Individual lobules were composed of round or polyhedral tumour cells, which had a characteristic finely granular and vacuolated cytoplasm and eccentric hyperchromatic nuclei. Positive staining was observed with Periodic acid-Shiff, and immunohistochemistry for cytokeratin, alpha-1 antitrypsin, and S-100 protein resulting in a final diagnosis of acinic cell carcinoma. Acinic cell carcinoma represents a well-established, although uncommon, entity in the classification of neoplasms of salivary gland origin. The parotid salivary gland is the most frequent site of acinic cell carcinoma, whereas the lip is a particularly unusual site. The unusual presentation of this tumour may lead to confusion with a mucocele. Given these findings, we suggest that acinic cell carcinoma should be considered in the differential diagnosis of any mucocele-like mass on the lower lip.

Biomarkers, Tumor↗
PubMed2005

Reduction of excessive electrical stimulus during electric pulp testing.

AIM: To measure excessive electrical stimulus time during pulp testing via electromyography (EMG) in the anterior belly of the digastric muscle, voice and finger movement, and to determine whether excessive stimulus time could be attenuated by a specially designed automatic circuit breaker on the basis of the EMG signal. METHODOLOGY: The signals from three human responses (EMG, finger and voice), induced by the Digitest (Parkell Inc., Farmingdale, NY, USA) electric pulp tester, were captured using a MP100 (Biopac System Inc., Goleta, CA, USA) and recorded into a personal computer. The excessive stimulus time from activation to the end of electrical stimulation was calculated for each of these three responses. The automatic circuit breaker was designed to disconnect the electrical output of the electric pulp testing (EPT) unit immediately after detecting the preset EMG level (100 mV). Each of the right central incisors and first premolars of 23 healthy individuals (16 males and seven females) was tested to see whether there was a difference in tooth type or gender. This was analysed by Wilcoxon signed rank test (nonparametric paired t-test) and Mann-Whitney test (nonparametric independent t-test), respectively. RESULTS: Amongst three human responses, the electrical onset occurred in the order of EMG, finger and voice. Excessive stimulus time was 347.8 +/- 78.3 ms when observed by the EMG, 264.9 +/- 63.9 ms when observed by finger span and 229.4 +/- 41.8 ms when observed by the voice, which were all found to be significantly different (P < 0.05). When the automatic circuit breaker was used, the excessive stimulus time was 61.0 ms, which was 286.8 ms shorter than that measured from EMG onset when using the conventional EPT. CONCLUSIONS: When the automatic circuit breaker was used, excessive stimulus time on the basis of EMG was attenuated on average by 286.8 ms.

Adult↗
PubMed2005

Functional expression of a recombinant copper/zinc superoxide dismutase of filarial nematode, Brugia malayi.

A gene encoding a copper/zinc superoxide dismutase (Cu/ Zn-SOD) of a filarial nematode, Brugia malayi, has been isolated and the biochemical properties of a functionally expressed recombinant enzyme were investigated. The cloned complementary DNA contained a single open reading frame of 477 bp encoding 158 amino acids (aa), which conserved metal-binding residues as well as residues specific for Cu/Zn-SODs. Comparison of the deduced aa sequence of the enzyme with that of other helminthes species, including filarial worms, exhibited high degree of similarities (49-98%). Recombinant enzyme of 32 kDa had an isoelectric point of 6.6 and was shown to consist of 2 subunits linked by interchain disulfide bonds. Enzyme activity of the recombinant protein was inhibited by potassium cyanide and hydrogen peroxide but not by sodium azide. It showed a wide range of pH optima, i.e., 7.0-11.0 and was highly resistant to heat inactivation.

Amino Acid Sequence↗
PubMed2004

Incidence of Haemophilus influenzae type b and other invasive diseases in South Korean children.

To determine incidence of invasive Haemophilus influenzae type b (Hib) disease in a defined population of Jeonbuk Province, Korea, children <5 years were evaluated in prospective, population-based surveillance of invasive bacterial diseases using standardized methods for patient referral, clinical evaluation and laboratory testing (optimized culture, latex agglutination, polymerase chain reaction). Vaccine utilization was assessed with vaccination histories of patients in surveillance, monthly data on Hib vaccine distribution and a coverage survey of clinic patients in study population. From September 1999 to December 2001, 2176 children were evaluated for possible meningitis, 1541 had no cerebrospinal fluid (CSF) findings of meningitis, 605 had CSF abnormalities (suspected bacterial meningitis) but no pathogen identified; six patients had probable Hib meningitis and eight had confirmed Hib meningitis. The annual suspected bacterial meningitis incidence was 258.4/100,000 <5 years and the probable/confirmed Hib meningitis incidence was 6.0/100,000 <5 years. Pneumococcal meningitis incidence was 2.1/100,000 <5 years and Group B streptococcal meningitis incidence was 0.17/1000 live births. A total of 69,589 Hib vaccine doses were distributed during the study. Hib vaccine coverage was negligible initially but increased to 16% (complete Hib immunization) and 27% (partial immunization) in final months of study. Suspected bacterial meningitis incidence was high but proven invasive Hib meningitis incidence was low. Hib was leading cause of bacterial meningitis yet bacterial pathogens were identified in only 4% of abnormal CSF. These findings may reflect truly low incidence, presumptive antibiotic treatment, partial Hib immunization, or incomplete clinical evaluations. Given the apparent Hib meningitis burden in Jeonbuk Province, additional studies to describe other invasive Hib syndromes, Hib-associated mortality and disability, and economic impact of Hib disease will be useful to guide public health decisions regarding routine Hib vaccine introduction.

Adolescent↗
PubMed2004

Thermodynamic and transport measurements of superconducting Na0.3CoO2.1.3H2O single crystals prepared by electrochemical deintercalation.

Superconducting single crystal samples of Na0.3CoO2.1.3H(2)O have been produced using an electrochemical technique which dispenses with the usual bromine chemical deintercalation method. In fully hydrated crystals, susceptibility and specific heat measurements confirm that bulk superconductivity has been achieved. The extracted normal state density of states indicates Fermi-liquid behavior with strong mass enhancement and a modest Wilson ratio. Measurements of H(c2) for H parallel c and H parallel ab reveal significant anisotropy, and the extracted value for the coherence length is about 100 A, consistent with an extremely narrow bandwidth.

Journal Article↗
PubMed2004

Screening of Korean herbal medicines used to improve cognitive function for anti-cholinesterase activity.

Methanolic extracts of seven herbs (Acorus calamus, Acorus gramineus, Bupleurm facaltum, Dioscorea batatas, Epimedium koreanum, Poria cocos and Zizyphi jujuba) used in traditional Korean medicine for improvement of memory and cognition in old age were tested for cholinesterase inhibitory properties using the Ellman colorimetric method. Significant inhibition of the enzyme at 200 microg/ml was observed for extracts from A. calamus and E. koreanum. The possible bases for the reputation of these and the other herbs tested are discussed in the light of previous investigations into their chemistry and biological activity.

Acetylcholinesterase↗
PubMed2003

Genetic analysis of the VP1 region of human enterovirus 71 strains isolated in Korea during 2000.

We have isolated Human enterovirus 71 (EV71) from stool and CSF samples taken from patients with acute flaccid paralysis, herpangina, or hand, foot and mouth disease in 2000. Both the cell culture-neutralization test and RT-PCR were used to detect enteroviruses. Rhabdomyosarcoma (RD), HEP2c, and BGM cells were used for the isolation of viruses, and serotypes were determined by the neutralization test using EV71-specific antiserum. For genomic analysis, we amplified a 437-bp fragment of the 5'-noncoding region of the enterovirus genome and a 484-bp fragment of the VP3/VP1 region of EV71 by RT-PCR, with positive results. Products amplified using an EV71-specific primer pair were sequenced and compared with other isolates of EV71. Analysis of the nucleotide sequences of the amplified fragments showed that the EV71 isolates from patients were over 98% homologous and belonged to the genotype C.

Amino Acid Sequence↗
PubMed2003

Expression of NOD2 in Paneth cells: a possible link to Crohn's ileitis.

BACKGROUND AND AIMS: Genetic variation in NOD2 has been associated with susceptibility to Crohn's disease (CD) and specifically with ileal involvement. The reason for the unique association of NOD2 mutations with ileal disease is unclear. To identify a possible link, we tested expression of NOD2 in intestinal tissue of CD patients and controls. PATIENTS AND METHODS: Fifty five specimens of ileum or colon from 21 CD patients, seven ulcerative colitis (UC) patients, and five controls with pathology other than CD or UC were stained for NOD2 using an immunoperoxidase method. RESULTS: Using a monoclonal antibody against NOD2 developed in our laboratory, we detected uniform expression of NOD2 in terminal ileum Paneth cells from controls and patients as well as in metaplastic Paneth cells in the colon. Mechanical purification showed enriched expression of NOD2 mRNA in ileal crypts. In Paneth cells, NOD2 was located in the cytosol in close proximity to the granules that contain antimicrobial peptides. We detected minimal NOD2 in the villous epithelium of the ileum or in the colonic epithelium from both CD patients and controls. CONCLUSIONS: These results suggest a role for NOD2 in the regulation of Paneth cell mediated responses against intestinal bacteria and a plausible mechanism to explain the selective association of NOD2 mutations with ileal disease. The impaired capacity of CD associated mutations to sense luminal bacteria may result in increased susceptibility to certain gut microbes.

Adolescent↗
PubMed2003

Improvement of pre- and post-processing environments of the dynamic two-dimensional reservoir model CE-QUAL-W2 based on GIS.

An Environmental Information System (EIS) coupled with a Geographic Information System (GIS) and water quality models is developed to improve the pre- and post-data processing function of CE-QUAL-W2. Since the accuracy of the geometric data in terms of a diverse water body has a great effect on the water quality variables such as the velocity, kinetic reactions, the horizontal and vertical momentum, to prepare the bathymetry information has been considered a difficult issue for modellers who intend to use the model. For identifying Cross Section and Profile Information (CSPI), which precisely contains hydraulic features and geographical configuration of a waterway, the automated CSPI extraction program has been developed using Avenue Language of the PC Arc/view package. The program consists of three major steps: (1) getting the digital depth map of a waterway using GIS techniques; (2) creating a CSPI data set of segments in each branch using the program for CE-QUAL-W2 bathymetry input; (3) selecting the optimal set of bathymetry input by which the calculated water volume meets the observed volume of the water body. Through those approaches, it is clear that the model simulation results in terms of water quality as well as reservoir hydraulics rely upon the accuracy of bathymetry information.

Automation↗
PubMed2003

Waste load allocation for water quality management of a heavily polluted river using linear programming.

A waste load allocation model using linear programming has been developed for economic water quality management. A modified Qual2e model was used for water quality calculations and transfer coefficients were derived from the calculated water quality. This allocation model was applied to the heavily polluted Gyungan River, located in South Korea. For water quality management of the river, two scenarios were proposed. Scenario 1 proposed to minimise the total waste load reduction in the river basin. Scenario 2 proposed to minimise waste load reduction considering regional equity. Waste loads, which have to be reduced at each sub-basin and WWTP, were determined to meet the water quality goal of the river. Application results of the allocation model indicate that advanced treatment is required for most of the existing WWTPs in the river basin and construction of new WWTPs and capacity expansion of existing plants are necessary. Distribution characteristics of pollution sources and pollutant loads in the river basin was analysed using Arc/View GIS.

Environmental Monitoring↗
PubMed2002

Enhanced expression of tandem multimers of the antimicrobial peptide buforin II in Escherichia coli by the DEAD-box protein and trxB mutant.

The tandem multimeric expression of various peptides has been explored by many researchers. However, expression levels have usually not been proportional to the degree of multimerization. To increase the expression level in Escherichia coli of tandem multimers of a cationic antimicrobial peptide, buforin II, fused to an anionic peptide, we studied the effect of the DEAD-box protein and the trxB mutant on the expression of tandem multimers. An expression vector with a tac promoter was more effective in directing multimeric expression than one with a T7 promoter. The expression level of large multimers was substantially increased with the tac promoter, possibly through stabilization of long transcripts by synchronization of transcription and translation. Coexpression of the DEAD-box protein, an RNA-binding protein, with the T7 expression system increased the expression level of multimers, especially large multimers, due to protection of the long RNA transcripts. In addition, the use of the trxB mutant also enhanced the expression level of tandem multimers, which contain two cysteine residues at both ends of the monomeric unit. It seems that disulfide bonds formed in the multimers in the trxB mutant might help efficient charge neutralization for inclusion body formation of the multimers, resulting in enhancement of expression. Our results show that the expression of multimers can be improved through the stabilization of the long transcripts by the DEAD-box protein or the expression, under an oxidizing environment, of the trxB mutant in which covalent cross-links through disulfide bonds facilitate inclusion body formation of the multimeric fusion peptide.

Anti-Bacterial Agents↗