Search PubMed⌕ Search

Biomedical subjects

H Kim

Publications and source records attributed to H Kim.

At least 217 records · Page 12Linked to original sources
PubMed2001

Blood transfusion increases radical promoting non-transferrin bound iron in preterm infants.

BACKGROUND: Blood transfusion has been recognised as a risk factor for the development of retinopathy of prematurity (ROP) or chronic lung disease (CLD) in preterm infants, but the precise mechanism involved is not understood. AIM: To investigate the level of non-transferrin bound "free" iron, which has the potential to promote the generation of reactive oxygen species, and its redox status in the plasma of preterm infants immediately before and after blood transfusion. METHODS: Twenty one preterm infants with a median gestational age and birth weight of 27 weeks and 1021 g respectively were prospectively enrolled in the study. Sixteen of the 21 infants developed ROP and/or CLD. The infants were transfused with concentrated red blood cells at a median age of 32 days. The plasma concentration of total bleomycin detectable iron (BDI) was measured and also the ferrous iron (Fe(2+)) activity by bleomycin-iron complex dependent degradation of DNA. RESULTS: Even before blood transfusion, BDI was detectable in one third of the blood samples, and all but one sample had ferrous iron activity. After transfusion, both BDI and ferrous iron activity were significantly increased, in contrast with the situation in full term infants. Plasma ascorbic acid (AA) concentration was significantly decreased after blood transfusion, whereas the level of its oxidation product, dehydroascorbic acid (DHAA), and the DHAA/AA ratio were significantly increased compared with before the transfusion. The activity of plasma ferroxidase, which converts iron from the ferrous to the ferric state, was appreciably decreased in preterm infants, as expected from their very low plasma caeruloplasmin concentration. CONCLUSIONS: Plasma non-transferrin bound iron was significantly increased in preterm infants after blood transfusion and existed partly in the ferrous form, because of the low ferroxidase activity and the reduction of ferric iron (Fe(3+)) by ascorbic acid. This finding was specific to preterm infants and was not observed in full term infants after blood transfusion. Non-transferrin bound "free" iron may catalyse the generation of reactive oxygen species, which may be responsible for the clinical association of blood transfusion with ROP and CLD.

Anti-Bacterial Agents↗
PubMed2001

Activation of K+ channels induces apoptosis in vascular smooth muscle cells.

Intracellular K+ plays an important role in controlling the cytoplasmic ion homeostasis for maintaining cell volume and inhibiting apoptotic enzymes in the cytosol and nucleus. Cytoplasmic K+ concentration is mainly regulated by K+ uptake via Na+-K+-ATPase and K+ efflux through K+ channels in the plasma membrane. Carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), a protonophore that dissipates the H+ gradient across the inner membrane of mitochondria, induces apoptosis in many cell types. In rat and human pulmonary artery smooth muscle cells (PASMC), FCCP opened the large-conductance, voltage- and Ca2+-sensitive KK+ (maxi-K) channels, increased K+ currents through maxi-K channels [I(K(Ca))], and induced apoptosis. Tetraethylammonia (1 mM) and iberiotoxin (100 nM) decreased I(K(Ca)) by blocking the sarcolemmal maxi-K channels and inhibited the FCCP-induced apoptosis in PASMC cultured in media containing serum and growth factors. Furthermore, inhibition of K+ efflux by raising extracellular K+ concentration from 5 to 40 mM also attenuated PASMC apoptosis induced by FCCP and the K+ ionophore valinomycin. These results suggest that FCCP-mediated apoptosis in PASMC is partially due to an increase of maxi-K channel activity. The resultant K+ loss through opened maxi-K channels may serve as a trigger for cell shrinkage and caspase activation, which are major characteristics of apoptosis in pulmonary vascular smooth muscle cells.

Animals↗
PubMed2001

Thyroid-stimulating hormone transcriptionally regulates the thiol-specific antioxidant gene.

Thiol-specific antioxidant (TSA) plays an important role in regulating cell differentiation and proliferation by modulating the hydrogen peroxide (H2O2) mediated responses in a variety of mammalian cells. Thyroid cells are constantly exposed to the actions of reactive oxygen species (ROS), because they produce high levels of H2O2 in response to the physiological action of TSH (thyroid-stimulating hormone). Thyrocytes have several defense mechanisms against ROS, including TSA and SOD (superoxide anion dismutase). Using Northern blot hybridization, we tested the effects of TSH on TSA gene expression in FRTL-5 cells derived from rat thyroids. TSA mRNA expression increased following treatment of cells with TSH at concentrations greater than 10(-9) M. This effect was observed within 6 hours following treatment, and peaked at 8 hours. The effect was blocked by actinomycin D, but not by cycloheximide. The half-life of TSA mRNA was approximately 5.5 hours in the presence or absence of TSH, and that was not affected by TSA mRNA stability. The effects on TSA gene expression were specific to TSH. Other growth factors (e.g., insulin, transferrin and hydrocortisone) did not alter TSA expression. Our results are the first indication that TSH regulates the expression of TSA transcriptionally in thyrocytes.

Animals↗
PubMed2001

Role of nitric oxide and mucus in ischemia/reperfusion-induced gastric mucosal injury in rats.

The present study aims at investigating the role of nitric oxide (NO) on the oxidative damage in gastric mucosa of rats which received ischemia/reperfusion (I/R) and its relation to mucus. NO synthesis modulators such as L-arginine and N(G)-nitro-L-arginine methyl ester (L-NAME) were injected intraperitoneally to the rats 30 min prior to I/R which was induced by clamping the celiac artery and the superior mesenteric artery for 30 min and reperfusion for 1 h. As a result, I/R increased lipid peroxide production and decreased the contents of glutathione (GSH), cGMP and mucus as well as GSH peroxidase activities of gastric mucosa. I/R decreased the activity and protein of NO synthase (NOS) in gastric mucosa. Pretreatment of L-arginine, a substrate for NOS, prevented I/R-induced alterations of gastric mucosa. However, L-NAME, an NOS inhibitor, deteriorated oxidative damage induced by I/R. In conclusion, NO has an antioxidant defensive role on gastric mucosa by maintaining mucus, GSH and GSH peroxidase, which were related to preservation of cGMP and NOS in gastric mucosa.

Animals↗
PubMed2001

Phenytoin-induced lingual tonsil hyperplasia causing laryngeal obstruction.

The effects of phenytoin sodium on lymphoid tissue have been known for some time. However, its effect on the lymphoid tissue of Waldeyer's ring is unreported in the otolaryngology literature. We present the case of a 78-year-old woman who was treated with phenytoin for generalized tonic-clonic seizures for 4 months and who subsequently developed lingual hyperplasia that caused laryngeal obstruction eventually requiring a tracheotomy. Of note, no history of airway compromise or difficulty with intubation from a prior operation 20 years ago was reported; these findings suggest that the lingual tonsillar hyperplasia was a consequence of phenytoin therapy and not a preexisting condition. The findings of histopathologic evaluation were consistent with lymphoid hyperplasia without evidence of malignancy. We also report our operative management and follow-up of this rare condition.

Aged↗
PubMed2001

Immunohistochemical detection of scrapie prion proteins in clinically normal sheep in Pennsylvania.

Following diagnosis of scrapie in a clinically suspect Suffolk sheep, 7 clinically normal flockmates were purchased by the Pennsylvania Department of Agriculture to determine their scrapie status using an immunohistochemical procedure. Two of the 7 euthanized healthy sheep had positive immunohistochemical staining of the prion protein of scrapie (PrP-Sc) in their brains, nictitating membranes, and tonsils. The PrP-Sc was localized in the areas of the brain where, histopathologically, there was neurodegeneration and astrocytosis. The PrP-Sc occurred within germinal centers of the affected nictitating membranes and tonsils and was located in the cytoplasm of the dendrite-like cells, lymphoid cells, and macrophages. These results confirm that immunohistochemical examination of the nictitating membrane can be used as a screen for the presence of scrapie infection in clinically normal sheep at a capable veterinary diagnostic laboratory. In sheep with a PrP-Sc-positive nictitating membrane, the diagnosis of scrapie should be confirmed by histopathology and immunohistochemical examination of the brain following necropsy. Following full validation, immunohistochemistry assays for detection of PrP-Sc in nictitating membrane lymphoid tissues can improve the effectiveness of the scrapie control and eradication program by allowing diagnosis of the disease in sheep before the appearance of clinical signs.

Animals↗
PubMed2001

CT differentiation of pneumonic-type bronchioloalveolar cell carcinoma and infectious pneumonia.

The objective was to analyse the potential of CT to distinguish pneumonic-type bronchioloalveolar cell carcinoma (BAC) from infectious pneumonia. The study consisted of 21 patients with pathologically proven BAC and 30 patients with infectious pneumonia. Both groups of patients had patchy or diffuse consolidation of more than half the area of a lobe or lobes on CT. CT findings in these two groups were compared with regard to morphological appearance, including CT angiogram, air bronchogram, mucous bronchogram, contrast enhancement pattern, pseudocavitation, cavity with air-fluid level, location, satellite lesion, ground-glass opacity and bulging of the interlobar fissure. Air-filled bronchi were morphologically analysed as dilatation, stretching, sweeping, widening of the branching angle, squeezing and crowding. Lymphadenopathy and pleural effusion were also analysed. CT findings favouring the diagnosis of BAC included an air-filled bronchus within the consolidation with stretching, squeezing, sweeping, widening of the branching angle and bulging of the interlobar fissure (p<0.05). It is concluded that CT may be helpful in differentiating pneumonic-type BAC from infectious pneumonia if the air-filled bronchus within the consolidation shows stretching, squeezing, widening of the branching angle or bulging of the interlobar fissure.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2001

The role of serine-246 in cytochrome P450eryF-catalyzed hydroxylation of 6-deoxyerythronolide B.

A strongly conserved threonine residue in the I-helix of cytochrome P450 enzymes participates in a proton delivery system for binding and cleavage of dioxygen molecules. 6-Deoxyerythronolide B hydroxylase (P450eryF) is unusual in that the conserved threonine residue is replaced by alanine in this enzyme. On the basis of the crystal structures of substrate-bound P450eryF, it has been proposed that the C-5 hydroxyl group of the substrate and serine-246 of the enzyme form hydrogen bonds with water molecules 519 and 564, respectively. This hydrogen bonding network constitutes the proton delivery system whereby P450eryF maintains its catalytic activity in the absence of a threonine hydroxyl group in the conserved position. To further assess the role in the proton delivery system of hydroxyl groups around the active site, three mutant forms of P450eryF (A245S, S246A, and A245S/S246A) were constructed and characterized. In each case, decreased catalytic activity and increased uncoupling could be correlated with changes in the hydrogen bonding environment. These results suggest that Ser-246 does indeed indirectly participate in the proton shuttling pathway, and also strongly support our previous hypothesis that the C-5 hydroxyl group of the substrate participates in the acid-catalyzed dioxygen bond cleavage reaction.

Bacterial Proteins↗
PubMed2001

Effect of astaxanthin on the hepatotoxicity, lipid peroxidation and antioxidative enzymes in the liver of CCl4-treated rats.

Astaxanthin is one of many carotenoids present in marine animals, vegetables and fruits. Since carotenoids are known to have antioxidant properties, we tested to determine if astaxanthin could have protective effects in the CCl4-treated rat liver by activating the antioxidant system. Astaxanthin blocked the increase of glutamate-oxalacetate transaminase (GOT) and glutamate-pyruvate transaminase (GTP) activity and thiobarbituric acid reactive substances (TBARS) in response to carbon tetrachloride (CCl4), while causing an increase in glutathione (GSH) levels and superoxide dismutase (SOD) activities in the CCl4-treated rat liver. These results suggest that astaxanthin protects liver damage induced by CCl4 by inhibiting lipid peroxidation and stimulating the cellular antioxidant system.

Adjuvants, Immunologic↗
PubMed2001

How reliable is the ultrasound densitometer for community screening to diagnose osteoporosis in spine, femur, and forearm?

Dual X-ray absorptiometry (DXA) is the most widely used noninvasive, quantitative diagnostic method of measuring bone density, but it exhibits several limitations for the purpose of general screening and community-based study. Thus, we evaluated the feasibility of the ultrasound densitometer SoundScan Compact for screening the osteoporosis community. We compared the reliability of the SoundScan Compact's measurement to predict both osteopenia and osteoporosis at the spine, femur, and forearm measured by the XR-36. World Health Organisation criteria and Korean reference were used for the diagnosis of osteopenia and osteoporosis. Of the 1827 subjects screened in the community, we randomly selected and invited 106 subjects to our university hospital center for clinical epidemiology for further evaluation of their bone health using DXA. The site-specific relationships among speed of sound and bone mineral density at L2-L4 spine, femoral neck, trochanter, Ward's triangle, distal radius + ulna, proximal radius + ulna, and proximal radius were highly correlated with r values of 0.633, 0.632, 0.674, 0.632, 0.668, 0.78, and 0.777 respectively (all p < 0.0001). Of the 42 subjects defined as normal in the spine by SoundScan Compact's, 27 (64.3%) were also in agreement as the normal by the XR-36. However, an agreement of 43.5% (10/23) in osteopenia and 53.7% (22/41) in osteoporosis was less sensitive. Reliability tested by kappa statistics (kappa = 0.35; t = 5.3; p < 0.0001) revealed that the degree of agreement was not coincidental. On the femur, 54.8% (23/42) agreed as normal, 73.9% (17/23) as osteopenia, and 39% (16/41) as osteoporosis (kappa = 0.33; t = 5.5; p < 0.0001). Higher reliability was found in the forearm, with a kappa value of 0.48, t = 7.2, and p < 0.0001. A magnitude of agreement was also greater in the forearm, with 83.3% (35/42) agreement in normal, 52.2% (12/23) in osteopenia, and 64% (16/25) in osteoporosis. Although the SoundScan Compact's measures different bone properties and measurements are taken at different sites, it is a very useful instrument with a high correlation and high degree of variation and reliability to predict bone health at other sites such as the spine, femur, and forearm. The ultrasound densitometer such as SoundScan Compact's merits its use for community screening and in the primary care setting to detect osteopenia and osteoporosis for the purpose of early detection and prevention.

Absorptiometry, Photon↗
PubMed2001

Regulation of phosphatidylinositol-phosphate kinase IIgamma gene transcription by thyroid-stimulating hormone in thyroid cells.

This study was performed to evaluate the effects of thyroid-stimulating hormone (TSH) on phosphatidylinositol-4-phosphate 5-kinase type IIgamma (PIPKIIgamma) gene expression in the thyrocytes of FRTL-5 cells. Although PIPKIIgamma mRNA was expressed constantly in the absence of added TSH, its expression increased remarkably in the presence of 10(-9) M TSH. This increase started within 6 h of the addition of TSH, and reached a maximum at 8 h. The mRNA expression properties of PIPKIIgamma in the cells were identified using inhibitors. Actinomycin D blocked PIPKIIgamma transcription strongly, while cycloheximide did not. In an experiment using 5,6-dichlo-1-beta-d -ribofuranosylbenzimidaxole, the half-life of PIPKIIgamma mRNA was approximately 6 h in the presence or absence of TSH, and it was not affected by the stability of the PIPKIIgamma mRNA. The effects of TSH on PIPKIIgamma gene expression were specific, and other growth factors examined (transferrin, insulin and hydrocortisone) did not alter its expression. It is possible that the mechanism of PIPKIIgamma gene expression is involved in the permissive effect of the TSH-cAMP cascade proper. Our results indicate, for the first time, that the expression of PIPKIIgamma is regulated transcriptionally by TSH in thyrocytes.

Animals↗
PubMed2001

Functional fitness may be related to life satisfaction in older Japanese adults.

The relationship between functional fitness status and life satisfaction was assessed in older Japanese people from the perspective of quality of life (QOL). A total of 123 older men and women (M = 74.3 years, SD = 5.4) participated in the study. The questionnaire contained 21 questions covering eight structural factors pertaining to the feelings of life satisfaction in older people. The functional fitness test consisted of nine items representing the following five areas of fitness: muscular strength, agility, coordination, balance, and flexibility. The analysis revealed no overall correlation between the total fitness and the total life satisfaction scores, but some of the life satisfaction factors were significantly related to some functional fitness items (P < .01). The results suggest it is important for older people to maintain their functional fitness in order to manage a high quality of life.

Activities of Daily Living↗
PubMed2001

[The relationship between fall-related activity restriction and functional fitness in elderly women].

The purpose of this study was to assess the relationship between experiences of falls or fear of falling and functional fitness in the elderly. A total of 41 women, aged 66-88, who visited Fall Prevention Clinic in Tokyo Metropolitan Geriatric Hospital, underwent an interview and functional assessment. We used a questionnaire about falls, fear of falling, activity restriction, and twelve variables were used to assess functional fitness. Data were collected from June 2000 to November 2001. The subjects were classified into four subgroups: the faller group (n = 29) were subjects who had at least one or more experiences of falling accidents in the past one year; the non-faller group (n = 12) were subjects who did not have any falling accidents in the past one year; the activity restricted group (n = 12) were subjects who were restricted from going out because of fear of falling; the activity non-restricted group (n = 23) consisted of subjects who did not have any restriction concerning going out because of fear of falling. The results were: 1) Among all subjects, 85.4% had fear of falling. Among the subjects who had fear of falling. 34.3% had restricted outdoor activities due to the fear of falling. 2) Where 86.2% of the faller group responded that they had fear of falling. 83.3% of the non-faller group also responded as having fear of falling. Of the faller group, 44.0% had some restriction concerning going out because of fear of falling. In the non-faller group, 10.0% of them showed some restriction concerning going out because of fear of falling. The rate of activity restriction in the faller group was significantly higher (p < 0.05) than in the non-faller group. 3) The faller group had significantly reduced LNG with eyes open and closed, one-leg balance with eyes open, tandem walking, grip strength, and leg extension than the non-faller group. 4) The activity-restricted group exhibited significantly reduced one-leg balance with eyes open, Up & Go test, grip strength, and leg extension than the activity non-restricted group. In conclusion, lower leg strength and walking ability as well as history of falls are significant predictors of activity restriction in elderly women related to fear of falling.

Accidental Falls↗
PubMed2001

Immunohistochemical analysis of CD44s and CD44v6 in endometriosis and adenomyosis : comparison with normal, hyperplastic, and malignant endometrium.

The expression patterns of CD44s and CD44v6 were immunohistochemically compared with those of normal, hyperplastic and malignant endometrium. In normal endometria (n=37), endometrioses (n=46) and adenomyoses (n=20), the surface and glandular epithelial cells were negative for CD44s and CD44v6 in a proliferative pattern and positive in a secretory pattern, whereas the stroma was only positive for CD44s in both proliferative and secretory patterns. The endometrial hyperplasia (4 simple and 9 complex) had the identical patterns with normal proliferative phase of endometrium. Only one case showing complex hyperplasia with atypia was focally positive for CD44s and CD44v6 in glandular epithelia. CD44s and CD44v6 were positive in all endometrial adenocarcinomas (13), except one CD44s-negative case. In summary, the expressions of CD44s and CD44v6 in endometriosis and adenomyosis recapitulated those of normal cyclic endometrium. The expression patterns in endometrial hyperplasia were similar to those in normal proliferative endometrium, whereas the endometrial adenocarcinoma showed abnormal expressions for CD44s and CD44v6. Thus it was considered that the ectopic endometrium in endometriosis and adenomyosis was not aberrant as in endometrial carcinoma on the aspects of immunohistochemical expressions of CD44s and CD44v6.

Adenocarcinoma↗
PubMed2001

Helicobacter pylori infection in Korea.

Helicobacter pylori is a gram-negative bacterium that was first isolated in 1982. Since then, H. pylori infection in humans has been shown to be associated with gastritis, peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma as well. The epidemiology, transmission, and pathogenicity of H. pylori has been a subject of intensive study. Successful treatment improves the cure rate of peptic ulcerations and treatment with antimicrobials also decreases the recurrence rate of these diseases. Better regimens having less toxicity and a good eradication rate have also been developed. A better understanding of the pathophysiologic mechanisms relating to H. pylori induced mucosal damages would result in more options for the prevention of peptic ulcers and carcinogenesis. Korea has a relatively high incidence of H. pylori infection and gastric cancer. Growing interest has developed in view of its importance in being associated with various gastroduodenal diseases. Furthermore, along with a high incidence of H. pylori-related disease in Korea, because the interaction between H. pylori, host factors and environmental factors is important in disease pathogenesis, we need to have precise data on the characteristics of H. pylori-related diseases that occur in Korea. In the present report we review the epidemiology, transmission route, diagnosis, pathogenesis, treatment methods and relationship with gastroduodenal diseases with in special references to basic and clinical data that have been published.

Dyspepsia↗