Biomedical subjects

J G Kim

Publications and source records attributed to J G Kim.

At least 73 records · Page 4Linked to original sources

PubMed2001

Short-term phytohaemagglutinin-activated mononuclear cells induce endothelial progenitor cells from cord blood CD34+ cells.

Endothelial progenitor cells (EPCs) were recently demonstrated to exist in human cord blood. Phytohaemagglutinin (PHA), a potent mitogen for mononuclear cells was used to induce EPCs from unsorted cord blood mononuclear cells (CBMCs). Adherent cells in clusters appeared approximately 24 h after CBMCs were cultured in plain Roswell Park Memorial Institute media containing 10% fetal bovine serum (culture media) and PHA. Adherent cells were further propagated for 1 week in plain culture media. Flow cytometry and Di-I staining analyses showed that CD45-, CD34+, Flk-1+, CD31+ or VE-cadherin+ EPCs were induced and that they were mainly from the CD34+ cell compartment. When enriched CD34+ cells alone were stimulated with culture supernatant of the PHA-activated CBMCs, they neither proliferated readily nor induced EPCs. Because EPCs first appeared within the clustering cells that expressed high levels of fibronectin and vascular endothelial growth factor (VEGF), our data suggest that both cell-cell/cell-matrix interaction and the local VEGF action are important in the induction of EPCs. Thus, we demonstrate for the first time that EPCs are induced from human cord blood stem cell populations that interact with neighbouring PHA-activated CBMCs. This finding may have a significant implication in inflammatory cell-mediated vasculogenesis and angiogenesis in vivo.

Antigens, CD34↗

PubMed2001

Seroepidemiological study of Helicobacter pylori infection in asymptomatic people in South Korea.

BACKGROUND: Helicobacter pylori infection occurs throughout the world and causes gastroduodenal diseases in all age groups. The prevalence of H. pylori infection varies between countries and races. The aim of this study was to evaluate the seroprevalence of H. pylori infection in asymptomatic healthy people in South Korea. METHODS: From March 1998 to October 1998, 5732 asymptomatic subjects who responded to the self-assessment questionnaires from 54 hospitals in South Korea were enrolled in this study. The serum levels of antibodies for H. pylori immunoglobulinG were measured by using an ELISA test. RESULTS: The overall seroprevalence of H. pylori infection was 46.6% and there was no statistical difference between males (47.2%) and females (45.9%). In adults, a significant difference was observed between genders. According to the geographic areas, the high prevalent provinces were Kangwon (53.4%), Cheju (52.9%) and Cholla province (50.6%); Seoul (41.9%) was the lowest prevalent area. The seroprevalence increased with age and was highest when patients were aged in their 40s (78.5%). The characteristic feature of our study was that the infection rate was steeply increased in three age groups (10-12 year olds, 16-19 year olds and those aged in their 20s). In Seoul, there was no difference in the prevalence rate among the districts studied. CONCLUSIONS: This nation-wide seroprevalence of H. pylori infection in South Korea was 46.6%, which showed the transition from a developing country to a developed country. More studies on the epidemiological factors and the route of transmission of H. pylori infection should be warranted.

Adolescent↗

PubMed2001

The transcriptional regulator Yin Yang 1 activates the myelin PLP gene.

Inauguration of the myelin program in developing oligodendrocytes requires the activation of those genes that encode the myelin proteins and the enzymes responsible for the synthesis and degradation of myelin lipids. An activator of the most abundantly expressed myelin protein, proteolipid protein (PLP), has been identified in a yeast one-hybrid system. The ubiquitously expressed zinc finger protein Yin Yang 1 (YY1) recognizes the myelin PLP promoter in vitro and in vivo. When overexpressed in an oligodendrocyte cell line, YY1 enhances transcription of the PLP promoter. A truncated version of YY1 that includes only the four zinc finger domains has little effect. The binding site for YY1 in the PLP promoter (site 3) fits the YY1 consensus site and DNA-protein complexes containing site 3 can be supershifted with an antibody directed against YY1 protein. Moreover, oligonucleotides with a mutated version of the PLP promoter site 3 are unable to bind to nuclear proteins or to compete for binding in a gel shift system. Finally, mutation of this site greatly reduces the activity of a 1-kb PLP promoter region in transfected glial cells. Our results suggest that PLP is a target gene for the transcriptional regulator YY1. This versatile transcription factor and nuclear matrix protein may boost transcription of the PLP gene to meet the demands of actively myelinating oligodendrocytes.

Animals↗

PubMed2001

Changes in profiles of circulating insulin-like growth factor components during hormone replacement therapy according to the responsiveness to therapy in postmenopausal women.

OBJECTIVES: Objectives of this study were (1) to evaluate the changes in the profiles of circulating insulin-like growth factor and of insulin-like growth factor-binding proteins during hormone replacement therapy and their relation with responsiveness to hormone replacement therapy and (2) to investigate the relationship between the changes in these insulin-like growth factor components and the annual changes in bone mineral density in postmenopausal women. STUDY DESIGN: Insulin-like growth factor and insulin-like growth factor-binding proteins were measured by immunoradiometric assay and Western ligand blotting in sera from 39 postmenopausal women treated with sequential hormone replacement therapy for 1 year. Bone mineral density at the lumbar spine and the proximal portion of the femur was determined by dual-energy x-ray absorptiometry. RESULTS: No significant change in the serum levels of insulin-like growth factor II and insulin-like growth factor-binding protein was noted during hormone replacement therapy in either the responders to therapy or the nonresponders (women with >3% bone loss per year), but serum levels of insulin-like growth factor I and proportions of insulin-like growth factor-binding proteins 1, 2, and 4 decreased during hormone replacement therapy only in the former group. Changes in insulin-like growth factor components during hormone replacement therapy did not correlate with annual bone mineral density changes. CONCLUSION: Profiles of circulating insulin-like growth factor I and insulin-like growth factor-binding proteins might be involved in responsiveness to hormone replacement therapy, but changes in these components during hormone replacement therapy do not predict annual changes in bone mineral density.

Absorptiometry, Photon↗

PubMed2001

Alternative medicine use in HIV-positive men and women: demographics, utilization patterns and health status.

Between 1995 and 1997, 1,675 HIV-positive men and women using complementary and alternative medicine (CAM) were enrolled into the Bastyr University AIDS Research Center's Alternative Medicine Care Outcomes in AIDS (AMCOA) study. Funded by the National Institutes of Health (NIH) Office of Alternative Medicine (OAM) and National Institute of Allergy and Infectious Diseases (NIAID), the AMCOA study collected information on participant demographics, health status and use of conventional and CAM therapies. Participants from 46 states completed a baseline questionnaire, while additional clinical information (such as CD4 count and HIV-RNA viral load) was obtained from laboratory records. AMCOA participants reported using more than 1,600 different types of CAM therapies (1,210 CAM substances, 282 CAM therapeutic activities and 119 CAM provider types) for treating HIV/AIDS. Approximately two-thirds (63% n = 1,054) of the AMCOA cohort reported using antiretroviral drug therapy (ART) during the six-months previous to completing the baseline questionnaire, while 37% (n = 621) indicated they were not using ART. Of those not using ART, 104 subjects reported never having used any conventional medications for their HIV and 12 subjects used only non-prescription diarrhoea medications. The most frequently reported CAM substances were vitamin C (63%), multiple vitamin and mineral supplements (54%), vitamin E (53%) and garlic (53%). CAM provider types most commonly consulted by the AMCOA cohort were massage therapists (49%), acupuncturists (45%), nutritionists (37%) and psychotherapists (35%). CAM activities most commonly used were aerobic exercise (63%), prayer (58%), massage (53%) and meditation (46%). The choice of CAM therapies among the AMCOA cohort does not appear to be solely based on scientific evidence of efficacy of individual therapies. The majority of AMCOA subjects could be characterized as using integrated medicine, since an overwhelming proportion of the cohort consult with both conventional and CAM providers and use both conventional and CAM medications, yet few subjects reported that their conventional and CAM providers work as a team. These data and this cohort set the stage for conducting studies of health status changes associated with specific CAM therapies.

Acupuncture Therapy↗

PubMed2001

Analysis of metronidazole, clarithromycin and tetracycline resistance of Helicobacter pylori isolates from Korea.

Antibiotic resistance in Helicobacter pylori varies according to geographical region. We studied the primary resistance rates among 652 H. pylori isolated from Korea in relation to collection date, disease presentation, age and gender. Resistance rates were 40.6% (metronidazole), 5.9% (clarithromycin), 5.3% (tetracycline), 0% (amoxycillin), 1.5% (furazolidone) and 1.5% (nitrofurantoin). Resistance to metronidazole and clarithromycin increased from 1994 to 1999 (from 33.3 to 47.7% and 4.8 to 7.7%, respectively), but the differences only reached significance when rates of metronidazole resistance in women were compared with those in men (48.6 versus 36.9%).

Adolescent↗

PubMed2001

Bis[3,6-bis(6-methyl-2pyridyl)pyridazine-kappa2N2,N3]chlorocopper(II) perchlorate.

The title compound, [CuCl(C16H14N4)2]ClO4, consists of a mononuclear complex cation and a perchlorate anion. The coordination of the copper(II) ion exhibits a trigonal bipyramidal geometry, where the equatorial plane is composed of the Cl atom and two N atoms of the two pyridazine rings, and the axial positions are occupied by the N atoms of two methylpyridine rings.

Crystallography, X-Ray↗

PubMed2001

6,7-Bis(bromomethyl)-2,11,18,21,24-pentaoxatetracyclo.

The 17-crown-5 unit, C(26)H(26)Br(2)O(5), consisting of a 1,2-bis(bromomethyl) group, three benzo groups and diethylene glycol, was prepared from the reaction of 1,2,4,5-tetrakis(bromomethyl)benzene and bis-phenol in the presence of sodium hydride as a base. This molecule seems to offer an internal cavity for the formation of a host--guest complex.

Journal Article↗

PubMed2001

Geographic differences in the distribution of intestinal metaplasia in duodenal ulcer patients.

OBJECTIVE: A strong correlation exists between atrophic gastritis and the intestinal type of gastric carcinoma. Duodenal ulcer disease characteristically has an antral predominant gastritis and a lower risk for gastric cancer. The aim of this study was to investigate the extent and distribution of intestinal metaplasia in duodenal ulcer in countries differing in gastric cancer incidence. METHODS: Topographically mapped gastric biopsy specimens (median 11) were obtained from patients with duodenal ulcer in four countries (Korea, Colombia, USA, and South Africa). Sections were stained with a triple stain and evaluated for Helicobacter pylori (H. pylori), active inflammation, and intestinal metaplasia. RESULTS: One hundred and sixty-five patients with duodenal ulcer were examined (29 from Korea, 52 from Colombia, 62 from the USA, and 22 from South Africa). The percentage of biopsies with intestinal metaplasia was significantly greater in Korean patients (86%) compared with that in other countries (50%) (p = 0.0004). Intestinal metaplasia was most prevalent in the antrum lesser curve and greater curve, and the body lesser curve. Intestinal metaplasia was present in the gastric corpus of 38% of duodenal ulcer patients from Korea compared with an average of 10% elsewhere (p = 0.018). No differences were observed in the density or distribution of H. pylori infection or in the degree of active gastritis between countries. CONCLUSIONS: Although antral predominant gastritis is the prevalent pattern of gastritis in duodenal ulcer, intestinal metaplasia in the gastric corpus may be found with geographic differences. These findings suggest that duodenal ulcer and gastric cancer are not mutually exclusive diseases but are rather ends of the spectrum of H. pylori infection.

Adult↗

PubMed2001

Furazolidone- and nitrofurantoin-resistant Helicobacter pylori: prevalence and role of genes involved in metronidazole resistance.

The prevalence of furazolidone, nitrofurantoin, and metronidazole resistance among Helicobacter pylori strains was assessed with 431 clinical isolates. Fifty-two percent were metronidazole resistant, compared to 2% (7 of 431) with resistance to furazolidone and nitrofurantoin. All seven furazolidone- and nitrofurantoin-resistant isolates were also metronidazole resistant. rdxA, frxA, and fdxB knockouts did not result in furazolidone or nitrofurantoin resistance. These data suggest that furazolidone and nitrofurantoin may be good alternatives to metronidazole for treating H. pylori infection.

Anti-Infective Agents, Urinary↗

PubMed2001

Urinary calculi on computed radiography: comparison of observer performance with hard-copy versus soft-copy images on different viewer systems.

OBJECTIVE: The purpose of this study was to compare observer performance for detecting urinary calculi using abdominal computed radiography with hard-copy versus soft-copy images and with a high-resolution video monitor versus a liquid-crystal-display (LCD) monitor. MATERIALS AND METHODS: We compared observer performance for detecting urinary calculi using three sets of radiographs-hard-copy images, soft-copy images displayed on a LCD monitor (1280 x 1024 bits), and soft-copy images displayed on a high-resolution video monitor using receiver operating characteristic curve analysis with a continuous rating scale. Computed radiography was archived with a 2140 x 1760 pixel resolution and a 10-bit depth. The selected data set included 62 images: 27 images showing proven urinary calculi smaller than 6 mm and three in number, and 35 images containing no proven abnormalities. Eleven radiologists (three genitourinary radiologists and eight general radiologists) participated in the study. Interpretations of three sets of randomly distributed radiographs were performed individually in three separate sessions at 1-week intervals. RESULTS: No statistically significant differences were found in the area under the receiver operating characteristic curve for detecting urinary calculi or in the interpreting times between soft-copy and hard-copy images; the mean areas under the receiver operating characteristic curve of hard-copy images, soft-copy images displayed on an LCD monitor, and soft-copy images displayed on a high-resolution video monitor were 0.579, 0.610, and 0.732, respectively. However, soft-copy images showed relatively improved diagnostic accuracy among less experienced radiologists (p < 0.05). CONCLUSION: For detecting urinary calculi, soft-copy images offered a diagnostic accuracy similar to or slightly more accurate than that of hard-copy images obtained in a laser-printed film-based environment. The diagnostic performance with soft-copy images viewed on an LCD monitor was comparable to that of soft-copy images viewed on a high-resolution video monitor.

Data Display↗

PubMed2001

Characterization of UV-irradiated dense/porous collagen membranes: morphology, enzymatic degradation, and mechanical properties.

Collagen-based membranous materials of various shapes (gel, film, sponge) are known to be the most promising materials in terms of facilitating the regeneration of dermal defects. In this study, dense and porous collagen membranes were fabricated using air-drying and freeze-drying processes, respectively, and the effect of ultraviolet (UV) radiation on the degree of membrane crosslinking was evaluated by in vitro biodegradation and mechanical testing. A non-irradiated membrane group was used as the negative control and a glutaraldehyde (GA) treated group as the positive control. Scanning electron microscopy showed that, as the freezing temperature decreased to -196 degrees C, the resultant mean pore sizes also decreased; optimal pore size was obtained at a freezing temperature of -70 degrees C. In vitro biodegradation and mechanical testing demonstrated that GA treatment or 4 hours of exposure to UV radiation significantly increased both resistance to collagenase and mechanical strength versus the untreated controls, regardless of the collagen membrane type (dense or porous). Our results suggest that UV treatment is a useful tool for the fabrication of collagen membranes designed to be used as dermal dressings.

Animals↗

PubMed2001

Preparation of collagen modified hyaluronan microparticles as antibiotics carrier.

Hyaluronan (HA), a natural glycoaminoglycan featuring an extracellular matrix, has been suggested as an effective biocompatible material. In this study, the effectiveness of HA microparticles as a carrier system for antibiotics was evaluated, and their physicochemical characteristics were determined. Microparticles were fabricated by the gelation of sulfadiazine (SD) loaded HA solution with calcium chloride through either a granulation (GR-microparticles) or encapsulation (EN-microparticles) process, and atelocollagen was incorporated into the microparticles as an additive in order to improve their physical properties. The characteristics of the microparticles were examined by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and swelling test. In vitro release experiments were performed for 7 days and the released amount of SD was determined using high-performance liquid chromatography (HPLC). Microscopic observations revealed that the collagen incorporated HA particles had a more compact surface than the HA particles. DSC analysis determined a loss of SD crystallinity in the particles. Calcium chloride retarded the swelling of particles, whereas the loaded drug contents did not affect this property. Both GR-and EN-microparticles sustained SD release with initial bursting effect. SD release from EN-microparticles was faster than from GR-microparticles. In addition, the release rate was dependent on the SD content in the microparticles. These results suggest that collagen modified HA microparticles have a potential as a release rate controlling material for crystalline drugs such as SD.

Anti-Bacterial Agents↗

PubMed2001

Relevance of vacA genotypes of Helicobacter pylori to cagA status and its clinical outcome.

BACKGROUND: Determination of vacA mosaicism may be important because specific Helicobacter pylori vacA genotype can be used to predict different clinical outcome. The aim of this study was to assess the relationship of vacA genotypes of Helicobacter pylori to cagA status and its development of peptic ulcer diseases in Korean patients. METHODS: Gastric biopsy specimens were obtained from 53 patients with gastric ulcer(GU), 57 with duodenal ulcer (DU) and 26 with chronic gastritis(CG) patients; all patients were infected with Helicobacter pylori. Bacterial mRNAs in the gastric mucosa were amplified by RT-PCR, using synthetic oligonucleotide primers specific for the vacA and the cagA gene. Patients with vacA s1 subtype were further examined to determine whether they had s1a or s1b subtype. RESULTS: There was no correlation in frequency of vacA s1 and/or s1a genotype between CG and either GU or DU, as the vacA s1 and s1a/m1 were present in the majority of strains independent of clinical status(s1; 100.0% versus 94.3% or 93.0% and s1a/m1; 76.9% versus 62.3% or 64.9%, respectively). Likewise, there was no difference in the prevalence of the cagA gene between CG and either GU or DU patients (92.3% versus 90.6% or 98.2%, respectively). In addition, the cagA-negative status did not predict the presence of vacA s2 genotype. CONCLUSION: These results strongly suggest that either cagA or vacA s1 and/or s1a is not proved to be a useful marker to distinguish disease-specific Helicobacter pylori strains for the development of peptic ulcer diseases in Korean patients.

Adolescent↗

PubMed2001

Expression of mucosal cyto-chemokine mRNAs in patients with Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori-induced destruction of the gastroduodenal mucosal barrier is initiated with mucosal infiltration of inflammatory cells. Cytokines and chemokines have been suggested to play important roles in the migration and activation of these inflammatory cells into the mucosa. The present study aimed to investigate expression rates of cyto-chemokine mRNAs using gastric mucosal biopsy specimens. METHODS: In 98 patients infected with Helicobacter pylori, mucosal mRNA expression rates of cytokines (IL-1 beta, IL-6, and IL-10), C-C chemokines (macrophage inflammatory protein 1 alpha (MIP-1 alpha), and macrophage inflammatory protein 1 beta (MIP-1 beta), monocyte chemotactic and activating factor (MCAF), regulated on activation, normal T cell expressed and presumably secreted (RANTES)) and C-X-C chemokines (IL-8 and growth regulated a (GRO-alpha)) were examined using reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The expression rates of mRNA for IL-8, GRO-alpha, MIP-1 alpha and RANTES were significantly more increased in H. pylori-positive patients than in H. pylori-negative patients. However, the expressions of IL-1 beta, IL-6 and IL-10 mRNA were statistically not different between two groups. After eradication of H. pylori, expressions of mRNA for three cytokines (IL-1 beta, IL-6 and IL-10), four C-C chemokines (MIP-1 alpha, MIP-1 beta, MCAF and RANTES) and two C-X-C chemokines (IL-8 and GRO-alpha) were significantly decreased. CONCLUSION: These results suggest that C-X-C chemokines and some C-C chemokines play important roles in H. pylori-associated peptic ulcer diseases.

Adult↗

PubMed2001

Inactivation of Escherichia coli O1 57:H7, Listeria monocytogenes, and Lactobacillus leichmannii by combinations of ozone and pulsed electric field.

Pulsed electric field (PEF) and ozone technologies are nonthermal processing methods with potential applications in the food industry. This research was performed to explore the potential synergy between ozone and PEF treatments against selected foodborne bacteria. Cells of Lactobacillus leichmannii ATCC 4797, Escherichia coli O157:H7 ATCC 35150, and Listeria monocytogenes Scott A were suspended in 0.1% NaCl and treated with ozone, PEF, and ozone plus PEE Cells were treated with 0.25 to 1.00 microg of ozone per ml of cell suspension, PEF at 10 to 30 kV/cm, and selected combinations of ozone and PEF. Synergy between ozone and PEF varied with the treatment level and the bacterium treated. L. leichmannii treated with PEF (20 kV/cm) after exposure to 0.75 and 1.00 microg/ml of ozone was inactivated by 7.1 and 7.2 log10 CFU/ml, respectively; however, ozone at 0.75 and 1.00 microg/ml and PEF at 20 kV/cm inactivated 2.2, 3.6, and 1.3 log10 CFU/ml, respectively. Similarly, ozone at 0.5 and 0.75 microg/ml inactivated 0.5 and 1.8 log10 CFU/ml of E. coli, PEF at 15 kV/cm inactivated 1.8 log10 CFU/ml, and ozone at 0.5 and 0.75 microg/ml followed by PEF (15 kV/cm) inactivated 2.9 and 3.6 log10 CFU/ml, respectively. Populations of L. monocytogenes decreased 0.1, 0.5, 3.0, 3.9, and 0.8 log10 CFU/ml when treated with 0.25, 0.5, 0.75, and 1.0 microg/ml of ozone and PEF (15 kV/cm), respectively; however, when the bacterium was treated with 15 kV/cm, after exposure to 0.25, 0.5, and 0.75 microg/ml of ozone, 1.7, 2.0, and 3.9 log10 CFU/ml were killed, respectively. In conclusion, exposure of L. leichmannii, E. coli, and L. monocytogenes to ozone followed by the PEF treatment showed a synergistic bactericidal effect. This synergy was most apparent with mild doses of ozone against L. leichmannii.

Colony Count, Microbial↗

PubMed2001

Cecal rupture by Anoplocephala perfoliata infection in a thoroughbred horse in Seoul Race Park, South Korea.

A 7-year-old Thoroughbred horse was admitted to the Equine Hospital, Korea Racing Association with signs of colic. Based on the size of impactions, the clinical signs, the results of abdominal paracentesis and medical treatment, the prognosis was poor. The horse died 3 hours later following hopeless discharge. At necropsy, the caecum and large colon were fully filled with fecal contents and there was a rupture (10 cm in dia) in the latero- ventral caecum. The mucosa of the ileo-caecal and caeco- colic valves appeared to the hyperemic, edematous and ulcerous. There were many tapeworms in the affected mucosa. Histopathologically, lesions included hyperaemia, a deep necrotic inflammatory lesion and ulcers in the mucosa and submucosa of ileo-caecal and caeco-colic valves. One hundred thirty four faecal samples were obtained from 16 stables and submitted to parasitic examination. A total of 4 genera of eggs were recovered: Stongylus spp (82.1%), Anoplocephala perfoliata (10.5%), Bovicola equi (0.7%) and Parascaris equorum (1.5%). The major findings in this study are the presence of A perfoliata and its suspected association with the colic which led into an eventual caecal rupture. This study indicates the needs for an epidemiological survey of colic that is associated with Anoplocephala.

Animals↗

PubMed2000

IFNalpha/beta promotes cell survival by activating NF-kappa B.

IFNs play critical roles in host defense by modulating the expression of various genes via signal transducer and activator of transcription factors. We show that IFNalpha/beta activates another important transcription factor, NF-kappaB. DNA-binding activity of NF-kappaB was induced by multiple type 1 IFNs and was promoted by IFN in a diverse group of human, monkey, rat, and murine cells. Human IFN promoted NF-kappaB activation in murine cells that express the human IFNalpha/beta receptor-1 signal-transducing chain of the type 1 IFN receptor. IFN promotes inhibitor of kappa B alpha (IkappaBalpha) serine phosphorylation and degradation, and stimulates NF-kappaB DNA-binding and transcriptional activity. Importantly, IFN promotes cell survival by protecting cells against a variety of proapoptotic stimuli, such as virus infection and antibody-mediated crosslinking. Expression of superrepressor forms of IkappaBalpha, besides inhibiting IFN-mediated NF-kappaB activation and IkappaBalpha degradation, also enhanced apoptotic cell death in IFN-treated cells. We conclude that NF-kappaB activation by IFNalpha/beta is integrated into a signaling pathway through the IFNalpha/beta receptor-1 chain of the type 1 IFN receptor that promotes cell survival in apposition to various apoptotic stimuli.

Apoptosis↗