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Biomedical subjects

Tae Hwan Kim

Publications and source records attributed to Tae Hwan Kim.

16 recordsLinked to original sources
PubMed2006

In Vivo radioprotective effect of Panax ginseng C.A. Meyer and identification of active ginsenosides.

This study evaluated the effect of water extracts of Panax ginseng C.A. Meyer (PG), panaxadiol (PD), panaxatriol (PT), ginsenoside Rb(1), Rb(2), Rc, Rd, Re and Rg(1) on jejunal crypt survival, endogenous spleen colony formation and apoptosis in jejunal crypt cells in gamma-irradiated mice. Jejunal crypts were protected by pretreatment with PG, Rc and Rd. Administration of PG, PD, Rd and Re prior to irradiation resulted in an increase in the formation of endogenous spleen colonies. The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment with PG, PD, Rb(2), Rc, Rd, Re and Rg(1). In experiments on the effects of the individual ginsenosides, the rank order of activity was Rc > Rd > Rg(1) > Rb(2) > Re > Rb(1) on intestinal crypt survival assay, Re > Rb(2) > Rd > Rg(1) > Rb(1) > Rc on the spleen colony formation assay, and Rg(1) > Re > Rd > Rc > Rb(2) > Rb(1) on inhibiting the death of cells caused by apoptosis. The results indicated that Rc, Rd and Re may have a major radioprotective effect in mice irradiated with high and low doses of radiation. When the same experiments were performed using PD and PT, it was observed that most of the inhibitory effects came from PD rather than PT.

Animals↗
PubMed2006

Alcohol-induced bone degradation and its early detection in the alcohol-fed castrated rats.

The objective of this study was to examine alcohol-induced changes of bone in hormone-deficient males using the developed method. In the process of bone resorption, type I collagen crosslinking molecules, pyridinoline (PYD), are released into the circulation and cleared by the kidneys. (2)H(2)O as a tracer has been applied to measure the synthesis rates of slow-turnover proteins and successfully applied to bone collagen synthesis in our hormone deficiency rats. This study demonstrated for the first time, the early changes of the femur bone degradation in hormone-deficient male individuals, more influenced by alcohol through histopathological study, serum PYD assay, and (2)H(2)O labeling. We also observed that serum PYD was a sensitive pathological marker of bone degradation in castrated osteoporosis males and the unique features of (2)H(2)O labeling to measure the bone turnover collagen synthesis rates were excellent markers of bone degradation and aging.

Amino Acids↗
PubMed2006

Angiotensin-converting enzyme gene insertion/deletion polymorphism in Korean patients with systemic sclerosis.

To determine whether angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is associated with the development and clinical features of systemic sclerosis (SSc) in Korean, we studied seventy two Korean patients with SSc fulfilling the ACR preliminary classification criteria. The controls were 114 healthy, disease free Koreans. ACE I/D genotypes were determined by PCR method using oligonucleotides. Sixty eight patients (94.4%) were women and age at diagnosis was 43.5+/-12.6 yr old (mean+/-SD). Thirty nine patients (54.2%) had a diffuse type of SSc. There were no statistical differences in the frequencies of all ACE I/D genotypes and D allele between patients and controls, and neither between diffuse and limited types of SSc. ACE I/D gene polymorphism was not associated with the development of SSc in Korea. The investigation for the pathogenesis of SSc requires more studies about the role of other candidate genes such as endothelin, TGF-beta, nitric oxide, or angiotensin II receptor in addition to the ACE genes.

Adult↗
PubMed2005

A cytogenetic study of Korean native goat bred in the nuclear power plant using the micronucleus assay.

Cytogenetic and hematological analysis was performed on the peripheral blood lymphocytes (PBLs) obtained from Korean native goats bred in two nuclear power plants (Wolsong and Uljin) and a control area. The frequencies of gamma-ray-induced micronuclei (MN) in the cytokinesis-blocked (CB) lymphocytes at several doses were measured in three Korean native goats. The measurements performed after irradiation showed dose-related increases in the MN frequency in each of the donors. The results were analyzed using a linear-quadratic model with a line of best fit of y=0.1019D+0.0045D2+0.0093 (y=number of MN/CB cells and D=irradiation dose in Gy). The MN rates in the goats from the Wolsong and Uljin nuclear power plant, and the control area were 9.60+/-2.88, 6.83+/-1.47 and 9.88+/-4.32 per 1,000 CB lymphocytes, respectively. The apparent difference is not statistically significant. The MN frequencies of PBLs from goats bred in three areas means that the values are within the background variation in this experiment. The MN frequencies and hematological values were similar regardless of whether the goats were bred in the nuclear power plant or the control area.

Animals↗
PubMed2004

A case of medullomyoblastoma of cerebellopontine angle mimicking acoustic neuroma.

Medulloblastoma is a common malignant central nervous system neoplasm found mainly in children. One the contrary, medulloblastoma of the cerebellopontine angle, the location of the tumor is very unusual. This is the the first case of the medullomyoblastoma, a rare form of medulloblastoma, occurring in the cerebellopontine angle. A 15-year-old boy experienced a sudden hearing loss in the left ear. Conservative medical treatment failed, and temporal MR imaging revealed a heterogeneously enhancing mass at the left cerebellopontine angle cistern and in the internal auditory canal; therefore, the lesion was regarded as a typical acoustic neuroma. Few days before surgery, an ipsilateral facial palsy developed, and a follow-up MR imaging showed a rapid growth of the previous lesion. The extended translabyrinthine approach permitted surgical removal. And under pathological diagnosis of malignancy, radiation therapy and series of chemotherapy was performed.

Adolescent↗
PubMed2003

2-ketogluconic acid production and phosphate solubilization by Enterobacter intermedium.

Enterobacter intermedium, isolated from grass rhizosphere, exhibited a strong ability to solubilize insoluble phosphate. This bacterium oxidized glucose to gluconic acid and sequentially to 2-ketogluconic acid (2-KGA), which was identified using HPLC and GC-MS. The ability of E. intermedium to solubilize phosphate and produce 2-KGA produce in broth medium containing different components was monitored with air and without air supply. With an air supply, the production of 2-KGA markedly increased to about 110 g/l at day 10 in media containing 0.2 M gluconic acid, while it was about 65 g/l without gluconic acid addition. With an air supply, the concentration of soluble phosphate significantly decreased to 200-250 mg/l in media containing 1% CaCO3, whereas it was about 1000 mg/l without CaCO3 addition. Without an air supply, the concentration of 2-KGA and phosphate were negligible throughout the culture period.

Culture Media↗
PubMed2002

Enhancement of radiation response in human cervical cancer cells in vitro and in vivo by arsenic trioxide (As2O3).

Arsenic trioxide (As2O3) inhibits cell growth and induces apoptosis in certain types of cancer cells including acute promyelocytic leukemia, prostate and ovarian carcinomas, but its effect on response of tumor cells to ionizing radiation has never been explored before. Here we demonstrate that As2O3 can sensitize human cervical cancer cells to ionizing radiation both in vitro and in vivo. As2O3 in combination with ionizing radiation have a synergistic effect in decreasing clonogenic survival and in the regression of established human cervical tumor xenografts. Pretreatment of the cells with As2O3 also synergistically enhanced radiation-induced apoptosis. Apoptosis of the cells by combined treatment of As2O3 and radiation was associated with reactive oxygen species generation and loss of mitochondrial membrane potential, resulting in the activation of caspase-9 and caspase-3. The combined treatment also resulted in an increased G2/M cell cycle distribution at the concentration of As2O3 which did not alter cell cycle when applied alone. These results indicate that As2O3 can synergistically enhance radiosensitivity of human cervix carcinoma cells in vitro and in vivo, suggesting a potential clinical applicability of combination treatment of As2O3 and ionizing radiation in cancer therapies.

Animals↗
PubMed2002

Signal transduction mechanism via adenosine A1 receptor in the cat esophageal smooth muscle cells.

We investigated what adenosine receptor type exists and the signaling pathways on the contraction of circular muscle cells isolated by enzymatic digestion from the cat esophagus. Adenosine or the selective A1 receptor agonist R-PIA causes a concentration-dependent contraction. After pretreatment with A1 receptor antagonist, DPCPX, adenosine-mediated contraction was abolished. Adenosine-induced contraction was significantly increased when A1 receptors were preserved by pretreatment with DPCPX followed by inactivation of all unprotected receptors with N-ethylmaleimide. Adenosine- or R-PIA-induced contraction was significantly augmented in the preserved cells and the increase was abolished in the presence of the A1 receptor antagonist DPCPX. PTX abolished contraction induced by adenosine or R-PIA, implying that contraction activated by A1 receptor was coupled to a pertussis toxin (PTX)-sensitive G(i) protein. After permeabilization, contraction was inhibited by G(i2), but not by G(i1) and G(i3), antibodies. These data suggest that adenosine-induced contraction of esophagus depends on PTX-sensitive G(i2.) Adenosine- or R-PIA-induced contraction of esophageal smooth muscle cells was not affected by the phospholipase D (PLD) inhibitor rho-chloromercuribenzoic acid (rhoCMB), phospholipase A(2) (PLA(2)) inhibitor DEDA or PKC antagonist chelerythrine, but was significantly abolished by phospholipase C (PLC) inhibitor, neomycin. PLC-beta3 antibody inhibited R-PIA-induced contraction. R-PIA-induced contraction of esophageal muscle cells was inhibited by IP(3) receptor antagonist heparin, which suggests that the contraction of esophageal smooth muscle cells is dependent on phosphatidylinositol-specific phospholipase (PI-PLC) and IP(3). In conclusion, adenosine- and R-PIA-induced contraction in cat esophageal smooth muscle cell was mediated by A1 receptor. A1 receptor is coupled to PTX-sensitive G protein G(i2), which results in the activation of PI-PLC-beta3. PI hydrolysis by PI-PLC forms IP(3), which binds to IP(3) receptor on endoplasmic reticulum, resulting in the release of intracellular Ca(2+).

Adenosine↗
PubMed2002

A case of polymyositis with dilated cardiomyopathy associated with interferon alpha treatment for hepatitis B.

Polymyositis is a rare complication of interferon alpha treatment as a result of immune-modulating role of the drug itself. In this case, interferon alpha induced polymyositis and cardiomyopathy is diagnosed in a 33-yr-old male patient with history of chronic hepatitis B. To treat hepatitis B, interferon alpha was administered until the proximal muscle weakness developed. Thereafter, sixteen cycles of immunoglobulin treatment (400 mg/kg) along with corticosteroids were instituted and led to an improvement in subjective symptoms with decreases in level of CPK and LDH. However, dilated cardiomyopathy has not improved in spite of the cessation of interferon treatment. Unlike the persistently elevated serum HBV DNA level, the serum ALT and AST levels have gradually decreased. Our case shows that clinical symptoms of polymyositis improved with steroid and immunoglobulin treatment without deterioration of the hepatitis B. To our knowledge, this is the first case of polymyositis associated with dilated cardiomyopathy after the administration of interferon in a patient with hepatitis B.

Adrenal Cortex Hormones↗
PubMed2002

Undifferentiated spondyloarthropathy in Korea: focusing on peripheral arthritis.

Undifferentiated spondyloarthropathy (USpA) includes the forms that do not meet criteria for the established categories of spondyloarthropathy. The clinical spectrum of USpA is therefore wide and few studies have been published on USpA, especially peripheral arthritis. A total of 107 patients fulfilling the European Spondyloarthropathy Study Group criteria for SpA were studied retrospectively by a chart review and interview by a rheumatologist. Peripheral arthritis, excluding hip and shoulder involvement, occurred in 97 of the 107 patients (91%). Joint involvement tended to be monoarticular or pauciarticular, and most frequently developed in peripheral joints including the knee and ankle. Among the 97 patients with peripheral arthritis, only 37 (35%) had a persistent arthritis. HLA-B27 was detected in 80 patients (78%). Peripheral arthritis was found in the lower extremities regardless of symmetry or asymmetry and tended to run a benign course with only a few patients having persistent arthritis.

Adult↗
PubMed2002

Association Between FcgammaR IIa and IIIa polymorphism and clinical manifestations in Korean patients with adult-onset Still's disease.

High-dose intravenous immunoglobulins alter the disease activity of adult-onset Still's disease (AOSD). Because activation status of FcgammaR is possibly dependent on their genetic polymorphisms, we investigated whether the polymorphisms of FcgammaR IIa and IIIa are risk factors, and affect the clinical features of AOSD. Genomic DNA was extracted from 36 patients and from 197 healthy controls. Polymerase chain reaction for FcgammaR IIa and IIIa using the allele-specific primers and direct sequencing of FcgammaR IIIa polymorphic site were performed. The frequencies of FcgammaR IIa/IIIa genotype between patients with AOSD and controls were not different. The allelic frequencies of FcgammaR IIa/IIIa between patients with AOSD and controls were not different, either. However, the FcgammaR IIa-R/R131 genotype was associated with a higher concentration of hemoglobin (p=0.04) and stable liver function (p=0.009) than the other genotypes. The FcgammaR IIIa-F/F176 genotype was associated with significantly lower titers of serum ferritin (p=0.025), and higher serum albumin (p=0.037) and cholesterol (p=0.014) concentrations than the other genotypes. This study suggest that the FcgammaR IIa and IIIa polymorphisms might not be genetic risk factors for AOSD in Korean, but contribute to the activity of disease. FcgammaR IIa-R/R131 and IIIa-F/F176 genotypes, low-binding genotypes for IgG2a and G1, may have more protective effects in acute stage of the disease than the other genotypes.

Adult↗
PubMed2002

Acute acalculous cholecystitis associated with systemic lupus erythematosus with Sjogren's syndrome.

Both systemic lupus erythematosus and Sjogren's syndrome are autoimmune diseases. Almost all organs can be involved but the gall bladder is an unusual site. We report a 39-year-old woman with systemic lupus erythematosus and Sjogren's syndrome presenting with acute acalculous cholecystitis. It is a very rare complication and, in the literature review, surgical interventions are mostly applied for treatment. In our case, high dose corticosteroid was tried and clinical manifestations and radiologic findings were improved.

Acute Disease↗
PubMedDate not supplied

Application of physical force is essential to enrich for epidermal stem cells in primary human keratinocyte isolation.

We present an improved method to isolate epidermal cells and to enrich stem cell populations. The new method utilizes magnetic stirring during digestion of skin with trypsin-EDTA (magnetic stirring method). The magnetic stirring method significantly improves both cell yield and colony-forming efficiency (CFE) relative to conventional epidermal cell isolation methods, such as those involving trypsin-EDTA only, thermolysin, or dispase. The cell yield and the total number of colony-forming cells per square centimeter of adult foreskin were 7,064,000 +/- 95,000 cells and 96,030 +/- 31,990 cells by the magnetic stirring method, 1,128,000 +/- 111,000 cells and 10,192 +/- 2941 cells by trypsin-EDTA only, 3,279,000 +/- 842,000 cells and 5851 +/- 2989 cells by thermolysin, and 1,443,000 +/- 507,000 cells and 8843 +/- 3388 cells by dispase, respectively. The CFE was 1.15 +/- 0.32% by magnetic stirring, 0.95 +/- 0.35% by trypsin-EDTA only, 0.28 +/- 0.12% by thermolysin, and 0.83 +/- 0.30% by dispase. The levels of surface beta(1)-integrin expression skewed to the right with the magnetic stirring method, implying increased proportion of beta(1)-integrin-bright cells (putative stem cells). Isolated keratinocytes developed fully differentiated epidermis when they were grafted onto nude mice. In conclusion, cell isolation by the magnetic stirring method is advantageous over conventional epidermal cell isolation methods, by which full range of basal epidermal cells including stem cells, transiently amplifying cells, and differentiating cells can be isolated and allow shorter expansion time for maximal coverage of wound sites after biopsies are taken from patients.

Animals↗
PubMedDate not supplied

Apoptosis in growing hair follicles following gamma-irradiation and application for the evaluation of radioprotective agents.

The usefulness of apoptotic fragments assay for investigating the radiation response of hair follicles and evaluation of radioprotective agents was examined in ICR mice. The extent of changes following 100 cGy (1000 cGy/min) was studied at 0, 2, 4, 8, 12, 16 or 20 hours after exposure. The maximal frequency was found 12 hours after exposure. The mice that received 50, 100, 200, 400 or 800 cGy of gamma-rays were examined 12 hours after irradiation. Measurements performed after gamma-ray irradiation showed a dose-related increase in apoptotic cells in each mouse studied. The dose-response curves were analyzed with a linear-quadratic model: the frequency (number per follicle) of apoptotic cells in the hair follicle was y = (0.05527 +/- 0.009574) D + (-0.00001988 +/- 0.00001337) D2 + 0.227 (r2 = 0.964, D = 100 cGy). The frequency of radiation (100 cGy)-induced apoptosis in hair follicles was reduced by pretreatment of diethyldithiocarbamate (DDC, i.p. at 30 minutes before irradiation, p < 0.05) or green tea (i.p. at 12 and 36 hours before irradiation, p < 0.01). From these results, it is thought that this model will be useful in the detection of radiation response and radioprotective agents.

Animals↗
PubMedDate not supplied

Measurement of micronuclei by cytokinesis-block method in human, cattle, goat, pig, rabbit, chicken and fish peripheral blood lymphocytes irradiated in vitro with gamma radiation.

The frequencies of gamma-ray-induced micronuclei (MN) in cytokinesis-blocked (CB) lymphocytes at several doses were measured in three donors of seven species (human, cattle, goat, pig, rabbit, chicken, fish). Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors of human, cattle, goat, pig and rabbit. The relative sensitivity of cattle, goat, pig and rabbit in peripheral blood lymphocytes (PBLs) compared with human PBLs was estimated by best fitting linear-quadratic model based on the radiation-induced MN data over the range from 0 cGy to 400 cGy. In the case of MN frequency with 0.2, the relative sensitivities of cattle, goat, pig and rabbit PBLs were 0.86, 0.98, 0.41 and 0.39, respectively. These data indicate that the induction of MN in CB cells following irradiation is similar in human, cattle and goat PBLs, while PBLs from pig and rabbit were much less sensitive to the MN induction effects of gamma-radiation than those from human. The micronucleus counts failed to show any evidence of radiation damage in the cells from chicken and fish. Measurements performed after irradiation showed a dose-related decrease in the formation of binucleated cells. We concluded that the use of CB cell from fish and chicken for detecting the results of radiation exposure was highly questionable. Our in vitro radiobiological study confirmed that the cytogenetic response obtained in blood from selected breeds of mammalian species can be utilized for application in environmental studies.

Animals↗