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Biomedical subjects

K H Kim

Publications and source records attributed to K H Kim.

At least 145 records · Page 8Linked to original sources

Effects of taurine on cerulein-induced acute pancreatitis in the rat.

Taurine, or 2-aminoethane sulfonic acid, is an intracellular amino acid and has been suggested to have a function in protecting biological systems from oxidative tissue damage. The aim of this study was to determine the effect of taurine against cerulein-induced acute pancreatitis in rats. Acute pancreatitis was induced by administering three subcutaneous injections of cerulein (40 microg/kg body weight) at 1-hour intervals, while taurine was administered intravenously at graded doses (30, 100, or 300 mg/kg, respectively) following the first cerulein injection. The severities of pancreatitis and lung injury were determined by measuring biochemical parameters, tissue myeloperoxidase (MPO), and histological changes. To clarify the mechanism of taurine, serum IL-1beta and TNF-alpha levels and tissue concentrations of malondialdehyde (MDA) were evaluated. In cerulein-induced acute edematous pancreatitis, treatment with taurine significantly decreased hyperamylasemia, tissue MPO, pancreatic edema, and the extent of pancreatic and pulmonary injury. Taurine decreased MDA concentration in the pancreas and lung, but not the serum cytokine concentration. We would conclude that taurine has beneficial effects in cerulein-induced acute pancreatitis and lung injuries by preventing the production of oxygen free radicals.

Acute Disease↗

The inhibitory mechanism of rebamipide on the mediator release in the guinea pig lung mast cells activated with specific antigen-antibody reactions.

This study aim was to assess the effects of rebamipide on the mechanism of histamine release and biosynthesis and release of leukotrienes caused by mast cell activation. We purified mast cells from guinea pig lung tissues by the use of enzyme digestion, the rough and the discontinuous density percoll gradient method. Mast cells were sensitized with IgG1 (anti-OVA) antibody and challenged with ovalbumin. Mast cells were also stimulated with A23187 and the intracellular Ca(2+) level was measured. Histamine and leukotrienes were measured by automated fluorometric analyzer and radioimmunoassay, respectively. The intracellular Ca(2+) level was analyzed using a confocal laser scanning microscope. Protein kinase C (PKC) activity was determined by protein phosphorylated with [gamma-(32)P]ATP. The phospholipase D activity was assessed by the labeled phosphatidylalcohol. Mass 1,2-diacylglycerol (DAG) was measured by the [(3)H]DAG produced when prelabeled with [(3)H]myristic acid. PLA(2) activity was determined by measuring the arachidonic acid released from the labeled phospholipids. Rebamipide decreased the releases of histamine and leukotrienes, and completely blocked Ca(2+) influx during mast cell activation by antigen-antibody reactions. It also decreased the release of histamine and leukotrienes during mast cell activation by A23187. The PKC and PLD activities were also decreased by rebamipide in a dose-dependent manner. Rebamipide inhibited the mass DAG production and PLA(2) activity during mast cell activation. The data suggest that rebamipide inhibits intracellular signals and blocks Ca(2+) influx in mast cells activated by specific antigen-antibody reactions, which in turn inhibits histamine release and leukotriene generation.

Alanine↗

Interaction of blood components with heparin-immobilized polyurethanes prepared by plasma glow discharge.

The blood compatibility of poly(ethylene oxide) (PEO)-grafted and heparin (Hep) immobilized polyurethanes was investigated using in vitro plasma recalcification time (PRT), activated partial thromboplastin time (APTT), platelet adhesion and activation, and peripheral blood mononuclear cell (PBMC) adhesion and activation. In the experiment with plasma proteins, the PRT of the polyurethane (PU) surface was prolonged by PEO grafting and further prolonged by heparin immobilization. The APTT was prolonged on PU-Hep, suggesting the binding of immobilized heparin to antithrombin III. The percentage of platelet adhesion on PU was not much different from that on acrylic acid- and PEO-grafted PUs (PU-C, PU-6, PU-33), yet was substantially decreased by heparin immobilization (PU-6-Hep, PU-33-Hep). The release of serotonin from adhering platelets was slightly suppressed on PEO-grafted PUs yet significantly suppressed on heparin-immobilized PUs. In the PBMC experiments, the adhesion and activation of the cells were significantly suppressed on heparin-immobilized PUs, and the amount of interleukin-6 (IL-6) released from PBMCs stimulated with surface-modified PUs decreased with a decrease in PBMC adhesion.

Biocompatible Materials↗

Bifid epiglottis associated with Joubert's syndrome.

This report presents the case of a 2-year-old boy who had a bifid epiglottis associated with Joubert's syndrome. He had episodic tachypnea and apnea, inspiratory stridor, aspiration, and growth and mental retardation. Direct laryngoscopy demonstrated agenesis of the right half of the epiglottis and hypertrophied mucosa over the arytenoid cartilage. After the hypertrophied mucosa was partially vaporized with a CO2 laser, the inspiratory stridor soon improved and the aspiration was alleviated. Brain magnetic resonance imaging showed cerebellar vermian agenesis and enlargement of the fourth ventricle.

Abnormalities, Multiple↗

Clinical characteristics of unexplained sudden cardiac death in Korea.

In Western countries, sudden cardiac death (SCD) is closely related to coronary artery disease, but in Korea the clinical characteristics of SCD are not well determined. Over a 4-year period (June 1995 to May 1999), 186 cases of SCD, ranging in age from 16 to 75 years, were admitted to the Chonnam National University Hospital. In 82 (44.1%) of these, neither symptoms nor evidence of structural heart disease was found and so their clinical characteristics were investigated. There were 66 (80.5%) men and 16 (19.5%) women (male/female ratio = 4.1:1). The mean age was 50 +/- 14 years: 19 (23.2%) were in their 40s, 21 (25.6%) in their 50s, and 17 (20.7%) in their 60s. The time of circulatory collapse witnessed in 68 cases of SCD showed 2 peaks: between midnight and 03.00h (n=16, 23.5%) and between 09.00h and midday (n=15, 22.1%). Unexplained SCD occurred at home in 48 (64.9%) cases and on the street in 12 (16.2%); it occurred during normal daily routine activity in 23 (39.6%) and during sleep in 15 (25.9%). Thirty-three patients (40.2%) experienced various prodromal symptoms, including chest discomfort (n=13, 15.9%) and dyspnea (n=8, 9.8%). The electrocardiogram taken on arrival recorded asystole in 65 (79.3%) and ventricular fibrillation in 17 (20.7%). Idiopathic ventricular fibrillation was diagnosed in 14 (10 men, 4 women; 45 +/- 11 years) of 21 patients who recovered spontaneous circulation. Five (6.1%) patients were discharged alive, and an implantable cardioverter-defibrillator was implanted in 2. Unexplained SCD is common in Korea and develops predominantly in middle-aged males around midnight or in the late morning usually with no prodromal symptoms (59.8%). Idiopathic ventricular fibrillation is thought to be one of the important causes.

Adolescent↗

Continuous countercurrent extraction of hemicellulose from pretreated wood residues.

Two-stage dilute acid pretreatment followed by enzymatic cellulose hydrolysis is an effective method for obtaining high sugar yields from wood residues such as softwood forest thinnings. In the first-stage hydrolysis step, most of the hemicellulose is solubilized using relatively mild conditions. The soluble hemicellulosic sugars are recovered from the hydrolysate slurry by washing with water. The washed solids are then subjected to more severe hydrolysis conditions to hydrolyze approx 50% of the cellulose to glucose. The remaining cellulose can further be hydrolyzed with cellulase enzyme. Our process simulation indicates that the amount of water used in the hemicellulose recovery step has a significant impact on the cost of ethanol production. It is important to keep water usage as low as possible while maintaining relatively high recovery of soluble sugars. To achieve this objective, a prototype pilot-scale continuous countercurrent screw extractor was evaluated for the recovery of hemicellulose from pretreated forest thinnings. Using the 274-cm (9-ft) long extractor, solubles recoveries of 98, 91, and 77% were obtained with liquid-to-insoluble solids (L/IS) ratios of 5.6, 3.4, and 2.1, respectively. An empirical equation was developed to predict the performance of the screw extractor. This equation predicts that soluble sugar recovery above 95% can be obtained with an L/IS ratio as low as 3.0.

Biomass↗

Cell cycling status of human cord blood CD34+ cells during ex vivo expansion is related to the level of very late antigen expression.

Very late antigen-4 (VLA-4), which binds to the extracellular matrix protein fibronectin, is an integrin molecule known to be modulated during mobilization of CD34+ cells, and to be involved in signaling the mobilization stimuli. On the hypothesis that cell cycling status might be different depending on the level of VLA-4 expression, we investigated the DNA contents of human cord blood CD34+ cells during ex vivo expansion by recombinant human thrombopoietin and flt3-ligand with simultaneous measurement of surface VLA-4 at the 1st and 4th week. During this ex vivo expansion, expression of VLA-4 increased and almost all cells became VLA-4+ until the 4th day of culture. Expression of VLA-4 was maintained in the major population of the cultured cells until the 4th week. The cells in S/G2/M phase were greater in number in VLA-4 high fraction than in VLA-4 low fraction (n=4, p<.001). Furthermore, the fraction of cells in S/G2/M phase increased as the expression of VLA-4 became higher. These results suggest that cord blood CD34+ cells expressing high levels of VLA-4 have more proliferative activities.

Antigens, CD34↗

Detection of fetal erythroid cells from maternal blood using fluorescence in situ hybridization and liquid culture.

Fetal nucleated erythrocytes circulating in maternal blood are a potential source of fetal DNA for noninvasive prenatal genetic diagnosis. However, the estimated ratio of fetal to maternal cells is extremely small. In order to enrich these cells, we performed direct culture using a two-phase liquid system. Mononuclear cells were obtained from maternal blood samples at 8-10(+3) weeks of gestation and cultured in the first phase. After 4-5 days, the nonadherent cells were harvested and recultured with erythropoietin in the second phase for another 3-5 days. We examined cellular morphology, and counted the number of benzidine- positive cells and the percentage of glycophorin A/CD71 positive erythroid cells. We also did Kleihauer-Betke stain for Hb F, polymerase chain reaction (PCR) for SRY/DYZ1, chromosome analysis, and fluorescence in situ hybridization (FISH). The number of total erythroid cells reached about 0.1 x 10(6)-1.0 x 10(6)/mL with a purity of 84.0-97.3%. Hb F stain showed total erythroid cells of approximately 0.4 x 10(4)-9.8 x 10(4)/mL. Male DNA was detected in one case by PCR. In this case, the XY karyotype was confirmed by FISH and amniocentesis. This approach provides enriched source of fetal cells for further prenatal genetic analysis without complicated separation or sorting procedures.

Cell Culture Techniques↗

A case of torsade de pointes associated with hypopituitarism due to hemorrhagic fever with renal syndrome.

We describe a 51-yr-old man presenting with syncope due to torsade de pointes. The torsade de pointes was refractory to conventional medical therapy, including infusion of isoproterenol, MgSO4, potassium, lidocaine, and amiodarone. His past history, physical findings, and hormone study confirmed that QT prolongation was caused by anterior hypopituitarism that developed as a sequela of hemorrhagic fever with renal syndrome. The long QT interval with deep inverted T wave was completely normalized 4 weeks after starting steroid and thyroid hormone replacement. Hormonal disorders should be considered as a cause of torsade de pointes, because this life-threatening arrhythmia can be treated by replacing the missing hormone.

Hemorrhagic Fever with Renal Syndrome↗

A case of successful primary coronary intervention for the total occlusion of left main stem with the aid of abciximab.

A 61-yr-old male patient presented with severe chest pain with cardiogenic shock due to an extensive anterolateral myocardial infarction. Two-dimensional echocardiogram showed severe left ventricular systolic dysfunction (ejection fraction=17%). Emergent coronary angiogram obtained immediately after placing temporary pacing electrode revealed total thrombotic occlusion in the left main stem. We performed direct coronary intervention using kissing balloon technique with the aid of Abciximab (ReoPro) infusion. Residual stenosis with thrombus remained even after high pressure balloon dilatations, therefore we placed two stents, one in the ostia of left anterior descending (LAD) and the other in left circumflex artery (LCX). Coronary angiogram after kissing stents showed improved LAD and LCX flows without residual stenosis. Chest pain resolved and blood pressure normalized after coronary intervention. The whole procedure time was 15 min. Follow-up coronary angiogram taken one week later showed patent previous stented arteries, and echocardiography demonstrated 40% of left ventricular ejection fraction. The clinical course for one-year follow-up was uneventful.

Abciximab↗

Atlanto-axial subluxation syndrome and management of intractable headache, neck pain and shoulder pain with auricular stimulation: a clinical case report.

Atlanto-axial subluxation syndrome is a condition that is easily overlooked, misdiagnosed and mismanaged. Anatomy, neurovascular involvement and description of clinical manifestations are reviewed. Bi-Digital O-Ring Test is employed to establish an accurate diagnosis and its value and accuracy described briefly. Bi-Digital O-Ring Test has been an important diagnosis confirmation method (reconfirmed by CT or MRI in over 95% of more than 850 clinical cases) in this author's practice of spinal disorder and intractable pain management. A newly described device, the KIM-STIM, offers auricular stimulation of multiple points, using electrical microcurrent. Each unit is individually custom-molded to the patient's ear, and fitted with multiple electrodes. It was found to be very effective in managing the majority of intractable pain, especially pain requiring multiple daily treatments in order for the patient to live and function normally. The KIM-STIM device allows the patient to self-manage the pain, by day or night, thus allowing for a reduction or elimination of medication intake and diminishing the necessity for frequent doctor visits.

Acupuncture Points↗

Cutaneous photodamage in Koreans: influence of sex, sun exposure, smoking, and skin color.

BACKGROUND: Severe wrinkles and pigmentary changes of the exposed skin indicate substantial damage due to UV radiation. Many investigators believe that the principal manifestation of photodamage in Asians is pigmentary change rather than wrinkles. However, to our knowledge, no well-designed study has investigated the characteristics of cutaneous photodamage in Asian skin. OBJECTIVE: To access the severity of wrinkles and dyspigmentation in Koreans exposed to sun and who smoked. METHODS: We developed new photographic scales for grading wrinkles and dyspigmentation in 407 Koreans to assess the severity of the wrinkles and dyspigmentation. We interviewed subjects to determine cumulative sun exposure and smoking history, and measured the skin color of individual subjects. RESULTS: Our photographic scales provided a reliable evaluation of photodamage severity in Koreans. The pattern of wrinkling in both sexes is similar, but women tended to have more severe wrinkles (prevalence odds ratio, 3.7). However, the pattern of dyspigmentation differed between the sexes. Seborrheic keratosis is the major pigmentary lesion in men, whereas hyperpigmented macules are the prominent features in women. Cigarette smoking is an independent risk factor for wrinkles, but not for dyspigmentation, in Koreans, and causes additive detrimental effects to wrinkles induced by aging and sun exposure. The constitutive skin color did not show any correlation with wrinkles or dyspigmentation. However, facultative pigmentation (sun exposure index) may reflect lifetime sun exposure, and it shows a good correlation with wrinkles in Koreans. CONCLUSION: Wrinkling is a major feature of photoaging in Koreans, as are pigmentary changes; smoking, sun exposure, and female sex are independent risk factors for wrinkles.

Adult↗

Effects of priming a bipolar attribute concept on dimension versus concept-specific accessibility of semantic memory.

In Experiment 1, participants received behavioral information about a person that could be interpreted as either honest or unkind. Priming a concept along 1 dimension (e.g., honesty) increased the likelihood of spontaneously describing the target along this dimension (i.e., as honest), regardless of whether the primed concept was directly applicable for interpreting the target's behavior ("honest") or was its bipolar opposite ("dishonest"). Experiment 2 replicated this finding in a different, product domain. It further demonstrated that when information is ambiguous, primed concepts can influence not only the dimension along which the target is described but also the value it is assigned along this dimension. The effect of priming in both experiments was reflected in participants' overall evaluations of the targets as well as in their spontaneous descriptions of it. Results were consistent with the assumption that bipolar attributes are associatively linked in memory but are stored as separate concepts rather than as values along a bipolar continuum.

Adult↗

The ultrastructure of spermatozoa of the slender catfish Silurus microdorsalis (Teleostei, Siluriformes, Siluridae) with phylogenetic considerations.

The spermatozoa of the slender catfish Silurus microdorsalis examined using transmission and scanning electron microscopy are characterized by a tubular structure and the absence of axonemal fins. Their characteristics can be considered to represent a valid symplesiomorphy uniting the Siluridae and taxon-specific for this family. The tubules of Silurus spermatozoon are not observed in the other siluroids. Unusual tubules occur in Citharinus spermatozoa of Characiformes. In addition, there is a considerable similarity in the absence of axonemal fins between Siluridae and Characiformes. Thus the two shared characteristics provide strong evidence that there exists a phylogenetic link between Characiformes and Siluriformes. Silurus appears to be plesiomorphic in having lost the axonemal fins while retaining the tubules in midpiece. The spermatozoa of S. microdorsalis are similar to those of other siluroids having a spherical head with a deep nuclear fossa, a short midpiece and an elongated tail. However, there are some differences between Silurus and other siluroids in the orientation of the centrioles, the number of the mitochondria and the axonemal fins, and minor differences between S. microdorsalis and S. asotus, in particular the orientation of the centriolar complex, and the arrangement of the tubules and the mitochondria in the midpiece. The deep nuclear fossa represents a synapomorphy uniting the Siluriformes, while the shallow nuclear fossa and the absence of axonemal fins are shared by two orders, Characiformes and Cypriniformes.

Animals↗

Coordination of pancreatic HCO3- secretion by protein-protein interaction between membrane transporters.

Increasing evidence suggests that protein-protein interaction is essential in many biological processes including epithelial transport. In this report, we discuss the significance of protein interactions to HCO(3)(-) secretion in pancreatic duct cells. In pancreatic ducts HCO(3)(-) secretion is mediated by cystic fibrosis transmembrane conductance regulator (CFTR) activated luminal Cl(-)/HCO(3)(-) exchange activity and HCO(3)(-) absorption is achieved by Na(+)-dependent mechanisms including Na(+)/H(+) exchanger 3 (NHE3). We found biochemical and functional association between CFTR and NHE3. In addition, protein binding through PDZ modules is needed for this regulatory interaction. CFTR affected NHE3 activities in two ways. Acutely, CFTR augmented the cAMP-dependent inhibition of NHE3. In a chronic mechanism, CFTR increases the luminal expression of Na(+)/H(+) exchange in pancreatic duct cells. These findings reveal that protein complexes in the plasma membrane of pancreatic duct cells are highly organized for efficient HCO(3)(-) secretion.

Animals↗

Structural analysis of multifunctional peptide motifs in human bifunctional tRNA synthetase: identification of RNA-binding residues and functional implications for tandem repeats.

Human bifunctional glutamyl-prolyl-tRNA synthetase (EPRS) contains three tandem repeats linking the two catalytic domains. These repeated motifs have been shown to be involved in protein-protein and protein-nucleic acid interactions. The single copy of the homologous motifs has also been found in several different aminoacyl-tRNA synthetases. The solution structure of repeat 1 (EPRS-R1) and the secondary structure of the whole appended domain containing three repeated motifs in EPRS (EPRS-R123) was determined by nuclear magnetic resonance (NMR) spectroscopy. EPRS-R1 consists of two helices (residues 679-699 and 702-721) arranged in a helix-turn-helix, which is similar to other RNA binding proteins and the j-domain of DnaJ, and EPRS-R123 is composed of three helix-turn-helix motifs linked by an unstructured loop. When tRNA is bound to the appended domain, chemical shifts of several residues in each repeat are perturbed. However, the perturbed residues in each repeat are not the same although they are in the same binding surface, suggesting that each repeat in the appended domain is dynamically arranged to maximize contacts with tRNA. The affinity of tRNA to the three-repeated motif was much higher than to the single motif. These results indicate that each of the repeated motifs has a weak intrinsic affinity for tRNA, but the repetition of the motifs may be required to enhance binding affinity. Thus, the results of this work gave information on the RNA-binding mode of the multifunctional peptide motif attached to different ARSs and the functional reason for the repetition of this motif.

Amino Acid Motifs↗

A new strain of Cryptocaryon irritans from the cultured olive flounder Paralichthys olivaceus.

An obligate parasite, Cryptocaryon irritans, which is responsible for the white spot disease of marine fish is known to develop in the temperature regime over 19 degrees C. Recently, however, we found white spot disease of olive flounder Paralichthys olivaceus during winter at water temperatures ranging between 12 and 16 degrees C in Korea. In the present study we isolated a C. irritans-like ciliate from the affected fish and investigated its reproductive characters to compare the newly found ciliate with typical C. irritans. The newly found ciliate had an additional process in the reproductive stage, characterized by a budding before palintomic division, and it showed a higher ability to carry out tomitogenesis at a low temperature (16 degrees C) than at a high temperature (24 degrees C). Nevertheless, the present ciliates still had much in common with typical C. irritans with respect to clinical, histopathological, and morphological characters, suggesting that it is a new strain of C. irritans, adapted to lower water temperature.

Animals↗