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Biomedical subjects

D Y Kim

Publications and source records attributed to D Y Kim.

At least 127 records · Page 7Linked to original sources
PubMed2000

An integrated service digital network (ISDN)-based international telecommunication between Samsung Medical Center and Hokkaido University using telecommunication helped radiotherapy planning and information system (THERAPIS).

This study introduces the integrated service digital network (ISDN)-based international teleradiotherapy system (THERAPIS) in radiation oncology between hospitals in Seoul, South Korea and in Sapporo, Japan. THERAPIS has the following functions: (1) exchange of patient's image data, (2) real-time teleconference, and (3) communication of the treatment planning, dose calculation and distribution, and of portal verification images between the remote hospitals. Our preliminary results of applications on eight patients demonstrated that the international telecommunication using THERAPIS was clinically useful and satisfactory with sufficient bandwidth for the transfer of patient data for clinical use in radiation oncology.

Japan↗
PubMed2000

A comparative pharmacodynamic study of IY-81149 versus omeprazole in patients with gastroesophageal reflux disease.

OBJECTIVE: To evaluate and compare the pharmacodynamic effects of IY-81149 and omeprazole on gastric pH in patients with gastroesophageal reflux disease. METHODS: Sixty male and female volunteers with gastroesophageal reflux disease were enrolled in a double-blind, two-way, crossover, dose-ranging study. Subjects were randomized into three groups, with each group comparing the effect of one of three doses of IY-81149 (5, 10, or 20 mg) with 20 mg omeprazole. IY-81149 and omeprazole were administered once daily for 5 days. Continuous 24-hour pH measurements were performed before the first dose (baseline) and after the fifth dose in both periods. Gastric acid suppression was evaluated on the basis of the following parameters: AUC(0-24), median pH in a 24-hour interval (pHmedian), and the percent time in a 24-hour interval in which the gastric pH was greater than 4 (tpH > 4). The truncated AUC parameters AUC(0-8), AUC(8-16), and AUC(16-24) were also calculated. The effects of IY-81149 and omeprazole on gastric pH were compared by use of analyses of covariance. The dose-response relationship for IY-81149 was also evaluated. RESULTS: There were no statistically significant differences between 5 mg IY-81149 and 20 mg omeprazole in terms of AUC(0-24), pHmedian, tpH, 4, AUC(0-8), and AUC(8-16). IY-81149, at 10 mg, produced a significantly greater gastric acid suppression than omeprazole on the basis of the values of AUC(0-24), pHmedian, tpH > 4, AUC(8-16), and AUC(16-24). Administration of 20 mg IY-81149 produced a significantly greater gastric acid suppression on the basis of all parameters. All doses of IY-81149 were more effective than omeprazole during 16 to 24 hours after the dose was administered. CONCLUSIONS: Administration of 10 and 20 mg IY-81149 produced a statistically significantly greater and prolonged suppression of gastric pH than 20 mg omeprazole.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Degeneration of the acetabular cartilage in osteonecrosis of the femoral head: histopathologic examination of 15 hips.

Acetabular cartilage with subchondral bone was taken from the superior dome from 15 hips of 13 patients undergoing total hip arthroplasty due to osteonecrosis of the femoral head. The mean age of the patients was 40 years. There were 10 hips ARCO stage IIIA, and 5 hips stage IIIB. 3 of the cases were mild, 12 moderate, and 1 had severe arthrosis. The degree of collapse of the femoral head was significantly related to the degeneration of the acetabular cartilage on histological examination. Our observations support the view that patients with an ARCO Stage III hip do not benefit from head-preserving procedures. They may also explain why bipolar prosthesis gives poorer results than total hip arthroplasty, in cases of osteonecrosis of the femoral head.

Acetabulum↗
PubMed2000

Intravesical neuromodulatory drugs: capsaicin and resiniferatoxin to treat the overactive bladder.

Current pharmacologic treatment of the overactive bladder relies on anticholinergic drugs. However, these drugs often have troublesome side effects and frequently are given in doses insufficient to restore continence in patients with detrusor instability. We present the background and basic and clinical research dealing with intravesical instillation of capsaicin and resinfferatoxin as treatments for the overactive bladder. Capsaicin is the main pungent ingredient in "hot" peppers of the genus Capsicum. It is a specific neurotoxin that desensitizes C-fiber afferent neurons, which may be responsible for the signals that trigger detrusor overactivity. Studies with capsaicin over the past 8 years have demonstrated clinical efficacy with minimal long-term complications. Most of these studies have also shown that the acute pain and irritation associated with capsaicin are a major deterrent to widespread use. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin that appears to have similar efficacy but with much less acute side effects may be more useful. Intravesical instillation of capsaicin or resiniferatoxin is a promising treatment for the overactive bladder.

Administration, Intravesical↗
PubMed2000

Correction of axillary burn scar contracture with the thoracodorsal perforator-based cutaneous island flap.

Axillary scar contracture is observed frequently after severe burn insult and is usually accompanied by injuries to the adjacent area. Although many therapeutic methods, including skin grafting, Z-plasties, local flaps, island flaps, and free flaps, have been established, each technique has its own advantages and disadvantages in specific situations. The decision regarding which technique to use can only be made after consideration is given to the merits of the individual case. We applied thoracodorsal perforator-based cutaneous flaps to 5 patients with axillary burn scar contractures and damaged adjacent tissues. In 1 patient both axillae were involved. Elevated flaps as large as 11 x 27 cm in size were used. All flaps survived completely even when raised in scar tissue. The donor sites were closed primarily except one, which needed a skin graft. Three patients obtained satisfactory release with more than 160 deg shoulder abduction. In 2 patients, release was incomplete with only 110 deg shoulder abduction, but neither one required a second release. The range of motion in terms of shoulder abduction was improved preoperatively (30-90 deg) to postoperatively (110-170 deg). The thoracodorsal perforator-based cutaneous flap presents a very useful reconstructive method for the treatment of axillary defects.

Adult↗
PubMed2000

Wavelet compression of ECG signals by the set partitioning in hierarchical trees algorithm.

A wavelet electrocardiogram (ECG) data codec based on the set partitioning in hierarchical trees (SPIHT) compression algorithm is proposed in this paper. The SPIHT algorithm [1] has achieved notable success in still image coding. We modified the algorithm for the one-dimensional case and applied it to compression of ECG data. Experiments on selected records from the MIT-BIH arrhythmia database revealed that the proposed codec is significantly more efficient in compression and in computation than previously proposed ECG compression schemes. The coder also attains exact bit rate control and generates a bit stream progressive in quality or rate.

Algorithms↗
PubMed2000

Dual coenzyme specificity of Archaeoglobus fulgidus HMG-CoA reductase.

Comparison of the inferred amino acid sequence of orf AF1736 of Archaeoglobus fulgidus to that of Pseudomonas mevalonii HMG-CoA reductase suggested that AF1736 might encode a Class II HMG-CoA reductase. Following polymerase chain reaction-based cloning of AF1736 from A. fulgidus genomic DNA and expression in Escherichia coli, the encoded enzyme was purified to apparent homogeneity and its enzymic properties were determined. Activity was optimal at 85 degrees C, deltaHa was 54 kJ/mol, and the statin drug mevinolin inhibited competitively with HMG-CoA (Ki 180 microM). Protonated forms of His390 and Lys277, the apparent cognates of the active site histidine and lysine of the P. mevalonii enzyme, appear essential for activity. The mechanism proposed for catalysis of P. mevalonii HMG-CoA reductase thus appears valid for A. fulgidus HMG-CoA reductase. Unlike any other HMG-CoA reductase, the A. fulgidus enzyme exhibits dual coenzyme specificity. pH-activity profiles for all four reactions revealed that optimal activity using NADP(H) occurred at a pH from 1 to 3 units more acidic than that observed using NAD(H). Kinetic parameters were therefore determined for all substrates for all four catalyzed reactions using either NAD(H) or NADP(H). NADPH and NADH compete for occupancy of a common site. k(cat)[NAD(H)]/k(cat)[NADP(H)] varied from unity to under 70 for the four reactions, indicative of slight preference for NAD(H). The results indicate the importance of the protonated status of active site residues His390 and Lys277, shown by altered K(M) and k(cat) values, and indicate that NAD(H) and NADP(H) have comparable affinity for the same site.

Archaeoglobus↗
PubMed2000

Overexpression of human telomerase RNA in Helicobacter pylori-infected human gastric mucosa.

Telomerase, an enzyme associated with cellular immortality and malignancy, plays an important role in cellular immortalization and tumorigenesis. Furthermore, overexpression of the RNA component of the telomerase, called human telomerase RNA (hTR), has been demonstrated in various human cancers as an early event. The pattern of hTR expression following Helicobacter pylori (H. pylori) infection in human gastric mucosa was investigated by a radioactive in situ hybridization (ISH) assay. Paraffin-embedded sections of 50 biopsy specimens taken from the gastric antrum of individual patients infected to different extents with H. pylori, as well as normal gastric mucosa, were studied. In normal gastric mucosa, only weak hTR expression was noted and the expression was limited to basal cells of the gastric glands. However, the degree of hTR expression gradually increased in parallel with the degree of H. pylori infection. The mean scores of gastric mucosa with mild, moderate and severe degrees of H. pylori infection were 2.3, 2.8, and 3.7 times higher than that of normal gastric mucosa, respectively. The results of this study suggested that up-regulation of hTR expression is a frequent and early event associated with H. pylori infection in the gastric mucosa and may play some role in gastric carcinogenesis. Sufficient synthesis of hTR during this early stage may be a prerequisite for telomerase reactivation to occur in gastric cancer.

Adult↗
PubMed2000

Novel testing of human gastric motor and sensory functions: rationale, methods, and potential applications in clinical practice.

Sensitive and reproducible tests are essential to investigate the mechanisms of gastric motility and sensation in healthy humans and patients with unexplained upper gastrointestinal symptoms. Electrogastrography, manometry, scintigraphic emptying, and barostat studies with an intragastric balloon were initially used to understand physiology and pathophysiology of gastric motility. However, manometry and barostat studies are time-consuming, costly, and invasive, thus reducing their widespread clinical application. To overcome these shortcomings, several novel approaches have been proposed: water/nutrient drink test, paracetamol absorption test, 13C-octanoic acid or spirulina breath tests, ultrasonography, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and tensostat. The water/nutrient (satiety) test is a noninvasive test proposed as an alternative to sensory studies performed with an intragastric balloon. The satiety test cannot measure gastric accommodation; interpretation of sensory tests usually has required independent assessment of accommodation or compliance. The tensostat can be used as a gastric sensation test because it measures gastric wall tension, which is related to the perception of gastric distention. To measure gastric emptying, the paracetamol absorption test, 13C breath tests, ultrasound, or MRI can be used. The paracetamol absorption test can measure the gastric emptying of liquids. 13C breath test can measure the gastric emptying of solids or liquids and can achieve accuracy comparable with gastric scintigraphy. Ultrasonography requires special skills, and MRI requires costly equipment. To measure gastric accommodation to a meal, ultrasound, MRI, and SPECT have been proposed. The recently introduced SPECT requires an intravenous injection of 99mTc-pertechnetate, which the gastric mucosa specifically takes up, and specialized imaging and analysis, which have potential to be automated. Thus, novel, noninvasive approaches assess different dimensions of gastric motility and sensation testing. With further development of these techniques, refinement of their conduct and analysis, and validation of clinical usefulness, they are likely to be applicable in clinical practice to enhance cost-effective, evidence-based management of upper gastrointestinal symptoms. Such applications may provide an alternative to sequential empirical trials for symptoms.

Acetaminophen↗
PubMed2000

Essentiality, expression, and characterization of the class II 3-hydroxy-3-methylglutaryl coenzyme A reductase of Staphylococcus aureus.

Sequence comparisons have implied the presence of genes encoding enzymes of the mevalonate pathway for isopentenyl diphosphate biosynthesis in the gram-positive pathogen Staphylococcus aureus. In this study we showed through genetic disruption experiments that mvaA, which encodes a putative class II 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, is essential for in vitro growth of S. aureus. Supplementation of media with mevalonate permitted isolation of an auxotrophic mvaA null mutant that was attenuated for virulence in a murine hematogenous pyelonephritis infection model. The mvaA gene was cloned from S. aureus DNA and expressed with an N-terminal His tag in Escherichia coli. The encoded protein was affinity purified to apparent homogeneity and was shown to be a class II HMG-CoA reductase, the first class II eubacterial biosynthetic enzyme isolated. Unlike most other HMG-CoA reductases, the S. aureus enzyme exhibits dual coenzyme specificity for NADP(H) and NAD(H), but NADP(H) was the preferred coenzyme. Kinetic parameters were determined for all substrates for all four catalyzed reactions using either NADP(H) or NAD(H). In all instances optimal activity using NAD(H) occurred at a pH one to two units more acidic than that using NADP(H). pH profiles suggested that His378 and Lys263, the apparent cognates of the active-site histidine and lysine of Pseudomonas mevalonii HMG-CoA reductase, function in catalysis and that the general catalytic mechanism is valid for the S. aureus enzyme. Fluvastatin inhibited competitively with HMG-CoA, with a K(i) of 320 microM, over 10(4) higher than that for a class I HMG-CoA reductase. Bacterial class II HMG-CoA reductases thus are potential targets for antibacterial agents directed against multidrug-resistant gram-positive cocci.

Amino Acid Sequence↗
PubMed2000

Differentiation of hamster liver oval cell following Clonorchis sinensis infection.

Oval cells which appear in the liver after hepatic injuries are suspected to be progenitor cells for both hepatocytes and bile duct cells. Oval cell isolated from the livers of the hamsters treated with diethylnitrosamine and 2-acetylaminofluorene and infected with Clonorchis sinensis (CS). cultured for 2 weeks and evaluated for differentiation and plasticity by electron microscopy and immunohistochemistry. In the CS-uninfected group, glycogen granules and peroxisomes were noted in the cells that were cultured for 2 weeks. Starting at 1 week postculture, immunoreactivity of the cells to cytokeratin 19 markedly decreased but that to albumin and alpha-fetoprotein gradually increased. This means that oval cells isolated from hamsters that were not infected with CS differentiated toward hepatocyte lineage. However, in the CS-infected group, cultured cells contained numerous rough endoplasmic reticulum and showed immunoreactivity that was generally in reverse to that of CS-uninfected group, meaning that cells isolated following CS infection were primed by CS and differentiated toward bile duct cell lineage. The results of this study suggested that oval cells are indeed bipolar progenitor cells for hepatocytes and bile duct cells and can differentiate toward either lineage depending upon the priming factor.

2-Acetylaminofluorene↗
PubMed2000

Isolation of liver oval cells from hamsters treated with diethylnitrosamine and 2-acetyl aminofluorene.

Recently, cholangiocellular carcinoma (CCC) was successfully induced in the hamster by infecting with Clonorchis sinensis following hepatocarcinogen treatment and has been proposed as a suitable model to study the pathogenesis of human CCC. In this hamster model, oval cells are suggested to be cells of origin of CCC. More direct analysis of histogenesis of CCC would become possible if large numbers of highly purified oval cells of hamster origin are obtained. In this study, we describe successful isolation of highly purified oval cells from hamsters. Oval cells were induced by diethylnitrosamine and 2-acetylaminofluorene treatment under choline deficient diet and isolated by centrifugal elutriation method. This isolated cells were highly homogenous in size (10.9+/-1.1 microm in diameter) and had a high nuclear to cytoplasmic ratio, an oval-shaped nucleus and a few cytoplasmic organelles. Immunocytochemically, 85.4+/-1.6%, 75.1+/-2.0%, 62+/-1.5% and 25.6+/-2.7% of the isolated cells were positive for cytokeratin 19, OV-6, albumin and alpha-fetoprotein, respectively, indicating that these cells had phenotypic characteristics of both hepatocytes and bile duct epithelium. The isolated cells were therefore considered to be hamster oval cells.

2-Acetylaminofluorene↗
PubMed2000

Mobilization kinetics of CD34(+) cells in association with modulation of CD44 and CD31 expression during continuous intravenous administration of G-CSF in normal donors.

The aim of the present study is to evaluate the kinetics of CD34(+) cells and investigate the potential modulation of CD44 and CD31 expression on CD34(+) cells during continuous i.v. administration of G-CSF, thus to elucidate the possible mechanism of peripheral blood progenitor cell (PBPC) mobilization. Fifteen healthy donors were enrolled in this study. G-CSF (10 microg/kg/day) was administered for four consecutive days through continuous 24-h i.v. infusion. For measurement of complete blood counts, CD34(+) cell levels and their expression of CD44 and CD31, PB sampling was performed immediately before the administration of G-CSF (steady-state) and after 4, 8, 24, 48, 72, 96, and 120 h of G-CSF administration. The percentage and absolute number of CD34(+) cells significantly increased at day 3 (0. 55 +/- 0.09%, 51.12 +/- 24.83 x 10(3)/ml) and day 4 (0.47 +/- 0.09%, 46.66 +/- 24.93 x 10(3)/ml), compared to the steady-state level (0. 06 +/- 0.09%, 2.03 +/- 5.69 x 10(3)/ml). At day 3 to day 5 following the onset of G-CSF administration, a strong decrease of CD44 and CD31 expression was observed on mobilized CD34(+) cells compared to controls: the relative fluorescence intensity of CD44 and CD31 was, respectively, 50%-70% and 40%-90% lower than that of controls. We conclude that continuous i.v. administration of G-CSF apparently results in more rapid mobilization of CD34(+) cells, and downregulation of CD44 and CD31 on CD34(+) cells is likely to be involved in the mobilization of PBPC after treatment with G-CSF.

Adult↗
PubMed2000

Activation of p38 mitogen-activated protein kinase alpha and beta by insulin and contraction in rat skeletal muscle: potential role in the stimulation of glucose transport.

The stress-activated p38 mitogen-activated protein kinase (MAPK) was recently shown to be activated by insulin in muscle and adipose cells in culture. Here, we explore whether such stimulation is observed in rat skeletal muscle and whether muscle contraction can also affect the enzyme. Insulin injection (2 U over 3.5 min) resulted in increases in p38 MAPK phosphorylation measured in soleus (3.2-fold) and quadriceps (2.2-fold) muscles. Increased phosphorylation (3.5-fold) of an endogenous substrate of p38 MAPK, cAMP response element binder (CREB), was also observed. After in vivo insulin treatment, p38 MAPKalpha and p38 MAPKbeta isoforms were found to be activated (2.1- and 2.4-fold, respectively), using an in vitro kinase assay, in immunoprecipitates from quadriceps muscle extracts. In vitro insulin treatment (1 nmol/l over 4 min) and electrically-induced contraction of isolated extensor digitorum longus (EDL) muscle also doubled the kinase activity of p38 MAPKalpha and p38 MAPKbeta. The activity of both isoforms was inhibited in vitro by 10 micromol/l SB203580 in all muscles. To explore the possible participation of p38 MAPK in the stimulation of glucose uptake, EDL and soleus muscles were exposed to increasing doses of SB203580 before and during stimulation by insulin or contraction. SB203580 caused a significant reduction in the insulin- or contraction-stimulated 2-deoxyglucose uptake. Maximal inhibition (50-60%) occurred with 10 micromol/l SB203580. These results show that p38 MAPKalpha and -beta isoforms are activated by insulin and contraction in skeletal muscle. The data further suggest that activation of p38 MAPK may participate in the stimulation of glucose uptake by both stimuli in rat skeletal muscle.

Animals↗
PubMed2000

Detection of IgG antibody against Neospora caninum in cattle in Korea.

A total of 492 cattle sera was screened by IgG-ELISA against Neospora caninum (Nc-1 strain and a Korean isolate, KBA-2) and Toxoplasma gondii. Out of 492, 113 sera (23.0%) reacted positively to either Nc-1 or KBA-2 strains of N. caninum. Among the 113 positive sera, 92 sera (81.4%) reacted with antigens of both strains, but 6 sera (5.3%) with Nc-1 and 15 sera (13.3%) with KBA-2 strain only. And with T. gondii antigen, 6 sera (1.2%) were positive but all reacted with N. caninum antigen also. Western blot revealed typical binding pattern according to ELISA values, such that high OD group reacted specifically to the major surface proteins including 43 kDa protein. Seroprevalence of 23.0% indicates that neosporosis seemed to be one of major causes of abortion in cattle. It is suggested here to establish more epidemiological researches nationwide systematically.

Animals↗
PubMed2000

Lobular carcinoma in situ in sclerosing adenosis.

The initial presentation of breast malignancy as noninvasive carcinoma in an area of sclerosing adenosis is unusual. Especially, lobular carcinoma in situ in sclerosing adenosis sometimes can be a potential source of confusion with invasive lobular carcinoma. We report a case of lobular carcinoma in situ presenting in adenosis exhibiting patterns akin to invasive lobular carcinoma, thus leading to potential misdiagnosis. Overall architecture of the lesion as seen at lower power and immunohistochemistry can be useful to distinguish between sclerosing adenosis with lobular carcinoma in situ and infiltrating lobular carcinoma.

Breast Neoplasms↗