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Biomedical subjects

S S Kim

Publications and source records attributed to S S Kim.

At least 19 recordsLinked to original sources
PubMed2007

The effects of container materials and buffer additives on decreasing the iodide concentration in a disposal vault for spent nuclear fuel.

To retard the migration of iodine released from a spent fuel after the break of a container, the reducing effects on the concentration of the iodide by container corrosion products and some buffer additives were examined in a solution with bentonite. Iron and copper, and their corrosion products scarcely reduced the iodide concentration. And kaolinite, chalcopyrite, pyrite, copper ore and galena, known as having a sorption property for iodine, did not noticeably sorb the iodide. However, palm active carbon, silver metal and Ag2O lowered the iodide concentration. Especially, Ag2O put into a disposal container would effectively hinder the migration of iodine to the outside of a disposal vault without a great loss if the pore size of the compacted buffer layer is maintained below 1 mu m.

Buffers↗
PubMed2006

Global analysis of the human gastric epithelial transcriptome altered by Helicobacter pylori eradication in vivo.

OBJECTIVE: The transcriptional profile of gastric epithelial cell lines cocultured with Helicobacter pylori and the global gene expression of whole gastric mucosa has been described previously. We aimed to overcome limitations of previous studies by determining the effects of H pylori eradication on the transcriptome of purified human gastric epithelium using each patient as their own control. DESIGN: Laser capture microdissection (LCM) was used to extract mRNA from paraffin-embedded antral epithelium from 10 patients with peptic ulcer disease, before and after H pylori eradication. mRNA was reverse transcribed and applied on to Affymetrix cDNA microarray chips customised for formalin-fixed tissue. Differentially expressed genes were identified and a subset validated by real-time polymerase chain reaction (PCR). RESULTS: A total of 13 817 transcripts decreased and 9680 increased after H pylori eradication. Applying cut-off criteria (p<0.02, fold-change threshold 2.5) reduced the sample to 98 differentially expressed genes. Genes detected included those previously implicated in H pylori pathophysiology such as interleukin 8, chemokine ligand 3, beta defensin and somatostatin, as well as novel genes such as GDDR (TFIZ1), chemokine receptors 7 and 8, and gastrokine. CONCLUSIONS: LCM of archival specimens has enabled the identification of gastric epithelial genes whose expression is considerably altered after H pylori eradication. This study has confirmed the presence of genes previously implicated in the pathogenesis of H pylori, as well as highlighted novel candidates for further investigation.

Adult↗
PubMed2006

Influence of weight reduction by sibutramine on female sexual function.

BACKGROUND: It is well known that selective serotonin reuptake inhibitors (SSRIs) can cause sexual dysfunction, so it is possible that sibutramine, a serotonin and norepinephrine reuptake inhibitor, could induce sexual dysfunction. DESIGN AND SUBJECTS: The effect of sibutramine on sexual function was evaluated in 46 overweight and obese (body mass index (BMI) > or = 23 kg/m2) but otherwise healthy married women (28-44 years). Participants were randomly assigned at baseline to either the sibutramine or control group. The Female Sexual Function Index (FSFI) questionnaire was used to assess sexual function at baseline and after treatment with behavioral therapy plus sibutramine 10 mg once daily or behavioral therapy alone (control) for 8 weeks. RESULTS: Mean weight loss from baseline to week 8 was -6.03% in sibutramine group and -0.38% in the control group. There was significant improvement of FSFI total score, arousal domain score and lubrication domain score in the sibutramine group (P<0.05), and significant differences in arousal, orgasm, satisfaction domain score and total score (P<0.05) in favor of sibutramine. Decreases in body weight and BMI were correlated with the improvement of arousal (r = -0.44 and r = -0.48, respectively) and orgasm (r = -0.45 and r = -0.46, respectively) domains. CONCLUSION: Treatment with sibutramine plus behavioral therapy did not induce sexual dysfunction and sibutramine-induced weight reduction appeared to have a positive impact on sexual function in this small group of overweight and moderately obese women. The degree of improvement in sexual function was correlated with the degree of weight reduction.

Adult↗
PubMed2006

Hepatic intra-arterial injection of 3-bromopyruvate in rabbit VX2 tumor.

PURPOSE: To evaluate the antitumoral effects of an intra-arterial injection of 3-bromopyruvate (3-BrPA) on liver VX2 tumor in rabbits. MATERIAL AND METHODS: Twenty rabbits with surgically implanted liver VX2 tumors were used. The rabbits were divided into three groups: a control, a saline, and a 3-BrPA group. Four rabbits were not treated at all, and they served as the control group. The saline group (n = 6) received only intra-arterial saline injection. The 3-BrPA group (n = 10) received an intra-arterial injection of 3-bromopyruvate through the hepatic artery. The delivered amounts of 3-bromopyruvate were as follows: 25 ml of 0.5 mM in six rabbits, 25 ml of 1.0 mM in two rabbits, and 25 ml of 2.0 mM in two rabbits. Four days after intra-arterial injection, the rabbits were sacrificed and histopathologic analysis of the explanted livers was performed with comparison of the tumor necrosis ratio (a percentage of the necrotic area versus the entire tumorous area) in each group. RESULTS: The mean tumor necrosis ratio was 12.5+/-4.2%, 44.8+/-24.7%, and 49.4+/-14.3% in the control, saline, and 3-BrPA groups, respectively. Between the control and the saline group, and between the control and the 3-BrPA group the mean tumor necrosis ratio appeared to be significantly different (P<0.05). However, there was no statistical difference in the mean tumor necrosis ratio between the saline and the 3-BrPA group (P = 0.416). CONCLUSION: A single session of intra-arterial injection of 3-BrPA showed no better results in terms of tumor necrosis than that of saline injection in a rabbit VX2 tumor model.

Animals↗
PubMed2006

Comparison of the amount of nuclides released from the spent fuel in contact with and without a compacted bentonite block.

A spent LWR fuel specimen between Ca-bentonite blocks was leached in a simulated bentonite-saturated granitic water (SBGW) for 165 days and its results were compared with those of a specimen leached without a bentonite block. The amounts of Cs, Sb, Sr, Eu, Am, U and Pu released from a 4.3 mm thickness of a fuel pellet with a 50,400 MWD/MTU burn-up in the SBGW without a bentonite block were 2.2, 0.25, 0.15, 0.02, 0.01, 0.01 and approximately 5 x 10(-4)% of their inventories, respectively. However, the amounts of nuclides released from the specimen between the 1.4 Mg/m(3) bentonite blocks were decreased by three times at least. Moreover, the concentrations of the nuclides in the leachate were very low because most of them were retained in the bentonite blocks.

Bentonite↗
PubMed2006

Morphological adaptation of the bone graft and fused bodies after non-instrumented anterior interbody fusion of the lower cervical spine.

PURPOSE: To assess the remodelling process of the bone graft and fused bodies after non-instrumented anterior interbody fusion with autogenous iliac graft in patients with spondylosis, infections, fractures, or disorders of the cervical spine. METHODS: 68 patients aged 18 to 58 years who underwent non-plated anterior lower cervical interbody fusion with an iliac graft were retrospectively studied. Diagnoses of the patients were degenerative disc diseases (n=32), disc herniation (n=15), fractures (n=13), and tuberculosis (n=8). The Robinson and Smith technique was used to treat degenerative disc diseases and protruded disc, and the Bailey and Badgley procedure for fractures or tuberculosis of the cervical spine. 34, 25, and 9 patients underwent one-, 2-, and 3-segment fusions, respectively. 18 of the 25 patients underwent two-segment fusion with a single large bone block, and 7 with 2 separate bone blocks for each segment. Four of the 9 patients underwent three-segment fusion with a single large bone block, and 5 used separate grafts for each segment independently. Plain and stress radiography was primarily used to assess the fusion. Computed tomography and magnetic resonance imaging were also used in some patients. Some anterior graft extrusion (amounting to less than 10% of corresponding anteroposterior body width) was used to observe the remodelling during graft-take and thereafter. Postoperative cervical traction for 2 to 4 weeks, then cervical collar immobilisation for 4 to 12 weeks were strictly followed according to the numbers of fused segments. A halo vest was applied in 4 patients with fracture undergoing 3-segment fusion as they could not tolerate the prolonged bed rest or rigid cervical brace. RESULTS: The mean time for the graft to fuse was 8.6 (range, 7-14) weeks in patients who underwent each segment fusion with independent free grafts, and 10 and 14 weeks in those who underwent 2- and 3-segment single large graft fusion, respectively. The final loss of disc height and joint angle were negligible, regardless of the extent of fusion. Bony absorption of the anteriorly protruded part of the graft began at postoperative week 10 (range, 6-28), which coincided with the time of graft-take and initiation of remodelling. CONCLUSION: The earliest sign of bony absorption of the anteriorly protruded part of the graft indicated the initiation of the graft-take and the graft remodelling. The inwaisting sign of the surgically fused block of vertebral bodies was a morphological adaptation. Despite the altered biomechanics of the spine in the fused area, the inwaisting sign indicated maintenance of normal function at the parafusion motion segments.

Adolescent↗
PubMed2006

Peripheral T-cell lymphoma in the neck: CT findings of lymph node involvement.

OBJECTIVE: To describe the CT findings of lymph nodes of the neck involved in peripheral T-cell lymphomas (PTCL). MATERIALS AND METHODS: Twenty-seven patients with pathologically proved PTCL with involvement of the lymph nodes of the neck were enrolled in this study. We retrospectively evaluated the lymph nodes on CT images with special attention to nodal necrosis, the margin, and enhancement patterns. RESULTS: In the 27 patients studied, nodal necrosis and ill-defined margin were seen in 11 (41%) and 19 (70%), respectively. Heterogeneous enhancement of enlarged lymph nodes was noted on CT images in 19 (70%) of 27 patients. Homogeneous enhancement without ill-defined margin and/or nodal necrosis was only seen in 6 of 27 patients (22%). CONCLUSION: Necrosis, an ill-defined margin, and heterogeneous enhancement of enlarged lymph nodes in the neck are relatively common CT features of PTCL. For patients with cervical lymph node enlargement, the presence of these findings may suggest high-grade non-Hodgkin's lymphoma, including PTCL.

Female↗
PubMed2006

Reversed discrepancy between CT and diffusion-weighted MR imaging in acute ischemic stroke.

PURPOSE: We sought to determine whether an early CT ischemic lesion showing parenchymal hypoattenuation might be undetectable on diffusion-weighted imaging (DWI) in acute cerebral ischemia. MATERIALS AND METHODS: We retrospectively evaluated CT and MR images of 70 consecutive patients with acute middle cerebral artery (MCA) infarction. All patients underwent CT and MR imaging within 6 hours of symptom onset. We determined the presence of reversed discrepancy (RD), defined as an early ischemic lesion showing parenchymal hypoattenuation on CT but no hyperintensity on DWI. CT Hounsfield units (HU), apparent diffusion coefficients (ADCs), and perfusion parameters were calculated for RD lesions. RESULTS: RD was found in 9 (12.9%) patients and at basal ganglia (89%). The mean HU of RD lesion was lower than that of normal tissue (DeltaHU, 2.33 +/- 0.74, P < .001). RD lesions showed no significant decrease of ADC (ADC ratio, 0.97 +/- 0.07, P = .059) and cerebral blood flow (relative CBF, 0.87 +/- 0.20, P > 0.05). Delayed DWI hyperintensity occurred in 8 (88.8%) RD lesions, and all lesions progressed to infarction. In 6 (66%) of 9 patients with RD, Alberto Stroke Program Early CT scores of ischemic lesions were lower on CT than those on DWI. CONCLUSION: RD was uncommonly found mainly in basal ganglia, and all RD lesions progressed to infarction at follow-up. Early CT ischemic lesion showing parenchymal hypoattenuation may be undetectable on DWI, and DWI may underestimate extent of severe ischemic tissue in patients with acute MCA infarction.

Acute Disease↗
PubMed2005

Stabilization of interchange modes in mirror plasmas by a nonlinear rf-plasma wave coupling process.

Experimental and theoretical studies are made of the consequences of a nonlinear coupling process between pump rf waves and interchange modes in mirror plasmas. It is demonstrated that the interchange-stable operation window exists depending on the applied rf power and gamma=omega(0)/Omega(i), where omega(0) (Omega(i)) is the angular frequency of the applied rf wave (ion cyclotron frequency). Results are shown that the nonlinear wave coupling process gives rise to the operation window near the resonance (gamma approximately equal to 1), which is elucidated by theoretical analyses combined with full rf wave simulations.

Journal Article↗
PubMed2005

Structural determination of the low-coverage phase of Al on Si(001) surface.

The atomic structure of Al layer on Si(001)-(2 x 1) surface has been studied by coaxial impact collision ion scattering spectroscopy. When 0.5 monolayer (ML) of Al atoms are adsorbed on Si(001) at room temperature, it is found that Al adatoms are dimerized and Al ad-dimers are oriented parallel to the underlying Si dimers at the position of centering T3 site with a height of 1.02 Angstroms from the first layer of Si(001). The bond length of the Al dimer is 2.67 Angstroms. With increasing Al coverage up to one ML, Al ad-dimers still occupied near T3 site and the next favorable site is near HH site.

Journal Article↗
PubMed2005

Structural analysis of the reconstructed Si(001)-C surface.

The atomic structure of reconstructed Si(001)c(4 x 4)-C surface has been studied by coaxial impact collision ion scattering spectroscopy. When the 100L of ethylene (C(2)H(4)) molecules have been exposed on Si(001)-(2 x 1) surface at 700 degrees C, it is found that C atoms cause the ordering of missing Si dimer defects and occupy the fourth layer of Si(001) directly below the bridge site. Our results provide the support for the previous model in which a missing dimer structure is accompanied by C incorporation into the subsurface.

Journal Article↗
PubMed2005

Benign breast diseases associated with cyclosporine therapy in renal transplant recipients.

PURPOSE: Our aim was to correlate the radiologic characteristics of cyclosporine-induced benign breast diseases with clinical and pathologic findings. MATERIALS AND METHODS: The clinical, mammographic, and ultrasonographic records of 33 female renal transplant recipients who received cyclosporine were retrospectively reviewed. Eleven patients had 46 breast masses on ultrasonography. We performed core needle biopsies on 20 masses and reviewed the pathologic findings. RESULTS: Among 33 female renal transplant recipients, 11 (33%) had 46 benign breast lesions detected on ultrasonography. We performed core needle biopsies on 20 of the 46 masses. On pathologic examination, 12 were fibroadenomas, 6 showed fibrocystic changes, and 2 revealed dense fibrosis. Regardless of the final pathologic diagnosis, more than half of the lesions revealed severe lymphatic and venular swellings. Among 11 patients with breast lesions on ultrasonography, 10/11 (91%) showed multiplicity, and 7/11 (64%) bilaterality. Mammographically, patients with breast lesions revealed heterogeneous or extremely dense breast patterns, and 8 of 11 patients, circumscribed masses. Twenty-two patients without breast lesions showed scattered fibroglandular densities (n = 7), or heterogeneously dense (n = 11) or extremely dense (n = 4) breast patterns, and 3 of 22 patients showed vague or asymmetric densities that needed further evaluation. CONCLUSION: The development of new breast lesions in patients after renal transplantation should suggest a diagnosis of cyclosporine-induced benign breast disease including fibroadenoma, fibrocystic changes, and dense fibrosis.

Adult↗
PubMed2005

Magnetic resonance findings of primary central nervous system T-cell lymphoma in immunocompetent patients.

PURPOSE: To describe the MR findings of primary central nervous system T-cell lymphoma (T-PCNSL) in immunocompetent patients. MATERIAL AND METHODS: Seven patients with pathologically proven T-PCNSL were included in our study. The number, location, shape, enhancement pattern, and signal intensity of the tumors were determined. Diffusion-weighted images (DWI) and perfusion-weighted images (PWI) were obtained in four and two patients, respectively. Apparent diffusion coefficients (ADCs) were generated, and regions of interest were defined in each lesion. RESULTS: Four patients with T-PCNSL had a single mass, while the others had multiple lesions (four, three, and two lesions, respectively). All seven cases of T-PCNSL had a supratentorial location: 12 in the subcortical area and 1 in the thalamus. No leptomeningeal involvement was noted. All tumors showed iso- to low T1 and iso- to slightly high T2 signal intensity to the adjacent gray matter. Rim enhancement was seen in 5 of the 7 patients (71.4%), while heterogeneous and homogeneous enhancement was seen in each of two. On DWI and ADC maps, the enhancing lesions showed slight hyperintensity in three patients (mean ADC ratio, 0.92 +/- 0.06) and iso-intensity in the other (ADC ratio, 1.02 +/- 0.05). Cystic areas consistent with necrosis were noted in three patients. High-signal intensity area in the cortex was noted on T1-weighted images in three patients, suggesting hemorrhage. In two patients, the same signal intensity area was noted within the mass. The two masses on the relative cerebral blood volume (rCBV) map demonstrated either similar or slightly higher signal intensity than that of the contralateral white matter. The rCBV ratios of these two masses were 1.27 +/- 0.16 and 1.35 +/- 0.2, respectively. CONCLUSION: T-PCNSLs show a predilection for a subcortical location, a relatively high incidence of cortical or intratumoral hemorrhage, rim enhancement, or cystic-areas consistent with necrosis on magnetic resonance imaging. The lower rCBV ratio of the tumor might be helpful in differentiating T-PCNSL from other brain tumors such as high-grade glioma.

Adolescent↗
PubMed2005

Prognostic significance of glycaemic control in patients with HBV and HCV-related cirrhosis and diabetes mellitus.

AIMS: Diabetes mellitus (DM) is frequently observed in patients with cirrhosis, particularly that due to hepatitis C virus (HCV) infection. However, no studies have focused on the clinical significance of glycaemic control in cirrhotic patients because of their short life expectancy and poor hepatic function. The aim of this study was to evaluate the prognostic impact of glycaemic control in patients with hepatitis B virus (HBV) and HCV-related cirrhosis and DM. METHODS: A total of 434 patients with HCV-related (HCV group, n = 88) or HBV-related (HBV group, n = 346) cirrhosis were studied retrospectively. We determined the prevalence of DM and treatment methods for hyperglycaemia and status of glycaemic control, and the patients' outcome. RESULTS: The prevalence of DM was 43.2% (38/88) in the HCV group and 19.7% (68/346) in the HBV group. Patients in the HCV group were older with a female preponderance. DM was detected before the diagnosis of cirrhosis or simultaneously in 92% and 79% in the HCV and HBV groups, respectively. Most patients were treated with insulin or oral hypoglycaemic agents. However, blood glucose levels were maintained within the normal range in 34.2% of the HCV group and in 23.5% of the HBV group. Forty-six patients died during the observation period in both groups. Hepatic failure was the most common cause of death, and sepsis and variceal bleeding were more frequent in the HCV group than in the HBV group. Multivariate analysis showed that Child-Pugh class was the most important factor for survival in both groups. In the HCV group, the status of glycaemic control was a significant independent factor of survival (P = 0.018). In the HBV group, age and the development of spontaneous bacterial peritonitis were significant. CONCLUSION: DM is more frequent in patients with HCV-related cirrhosis than in patients with HBV. Strict control of blood glucose levels could improve survival in HCV patients. A precise assessment of the risks and benefits of glycaemic control is required to reduce the mortality and morbidity of patients with cirrhosis and DM.

Adult↗
PubMed2005

Treadmill running promotes functional recovery and decreases brain-derived neurotrophic factor mRNA expression following sciatic crushed nerve injury in rats.

AIM: Peripheral nerve injuries are commonly encountered clinical problems and often result in severe functional deficits. In the present study, the effects of treadmill running on the recovery rate of locomotor function and the expression of brain-derived neurotrophic factor (BDNF) mRNA following sciatic crushed nerve injury in rats were investigated. METHODS EXPERIMENTAL DESIGN: Comparative investigation was performed over 14 days. SETTING: Experimental animal laboratory. PARTICIPANTS: 24 male Sprague-Dawley rats weighing 200+/-10 g. Animals were randomly assigned into 3 groups: the sham-operation group, the sciatic nerve injury group, and the sciatic nerve injury and running group. INTERVENTIONS: The right sciatic nerve was crushed for 30 s using a surgical clip. Rats of the running group were made to run on a treadmill for 30 min once a day for 12 consecutive days. MEASURES: Functional recovery was analyzed using a walking track analysis which can be quantified with the sciatic function index (SFI) and BDNF mRNA expression was analyzed using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Sciatic crushed nerve injury showed characteristic gait changes showing decrease of SFI value and treadmill running significantly enhanced the SFI value. The level of BDNF mRNA expression was increased following sciatic crushed nerve injury and treadmill running significantly suppressed the sciatic nerve injury-induced increment of BDNF mRNA expression. CONCLUSIONS: It can be suggested that treadmill running after peripheral nerve injury is effective in the functional recovery by inhibition on the over-expression of BDNF mRNA.

Animals↗
PubMed2004

Experimental measurement of the electron energy distribution function in the radio frequency electron cyclotron resonance inductive discharge.

Recently, the existence of electron cyclotron resonance (ECR) in a weakly magnetized inductively coupled plasma (MICP) has been evidenced [ChinWook Chung et al., Phys. Rev. Lett. 80, 095002 (2002)]. The distinctive feature of the ECR effect in the MICP is efficacious heating of low-energy electrons. In the present paper, electron heating characteristics in the MICP have been investigated by observing electron energy distribution function dependencies on various external parameters such as gas pressure, driving frequency, and rf power (electron density). It is found that the ECR effect on electron heating becomes enhanced with decreasing pressure or increasing driving frequency. The ECR heating becomes weak at high rf power due to the electron-electron collisions.

Journal Article↗