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S W Kim

Publications and source records attributed to S W Kim.

At least 109 records · Page 6Linked to original sources
PubMed2001

Effects of collagen IV and laminin on the reconstruction of human oral mucosa.

To investigate the effects of basement membrane proteins on the reconstruction of mucosa equivalent, oral mucosa substitute were cultured on (1) type I collagen gels, (2) type IV collagen-coated type I collagen gels, (3) laminin-coated type I collagen gels, and (4) type I collagen gels containing both type IV collagen and laminin. H/E and PAS staining showed that the characteristics of the oral mucosa were preserved under all the experimental conditions. However, the basal keratinocytes appeared cuboidal when the type I collagen gels were coated with type IV collagen plus laminin. The expression of the differentiation markers was similar, but weak staining of filaggrin, K13, and involucrin was observed with the type IV collagen plus laminin coating. Furthermore, electron microscopy revealed that the size of the basal keratinocytes was relatively small and uniform when both type IV collagen and laminin were used. These findings suggested that these two major basement membrane proteins are important in the process of differentiation in mucosal keratinocytes.

Animals↗
PubMed2001

Interaction of sulfonylurea-conjugated polymer with insulinoma cell line of MIN6 and its effect on insulin secretion.

A carboxylated derivative of sulfonylurea (SU), an insulinotropic agent, was synthesized and grafted onto a water-soluble polymer as a biospecific and stimulating polymer for insulin secretion. To evaluate the effect of the SU-conjugated polymer on insulin secretion, its solution in dimethyl sulfoxide was added to the culture of insulinoma cell line of MIN6 cells to make 10 nM of SU units in the medium and incubated for 3 h at 37 degrees C. The culture medium was conditioned with glucose concentration of 3.3 or 25 mM. To verify the specific interaction between the SU (K+ channel closer)-conjugated polymer and MIN6 cells, the cells were pretreated with diazoxide, an agonist of adenosine triphosphate-sensitive K+ channel (K+ channel opener), before adding the SU-conjugated polymer to the cell culture medium. This treatment suppressed the action of SUs on MIN6 cells. Fluorescence-labeled polymer with rodamine-B isothiocyanate was used to visualize the interactions, and we found that the labeled polymer strongly absorbed to MIN6 cells, probably owing to its specific interaction mediated by SU receptors on the cell membrane. The fluorescence intensity on the cells significantly increased with an increase in incubation time and polymer concentration. A confocal laser microscopic study further confirmed this interaction. The results from this study provided evidence that SU-conjugated copolymer stimulates insulin secretion by specific interactions of SU moieties in the polymer with MIN6 cells.

Acrylic Resins↗
PubMed2001

Correlation of hematopoietic progenitor cell count determined by the SE-automated hematology analyzer with CD34(+) cell count by flow cytometry in leukapheresis products.

The yield of stem cell collection after mobilization is crucial for autologous peripheral blood stem cell (PBSC) transplantation. Quantitative determinations of CD34(+) cells using flow cytometry or stem cell culture have been used, but these methods require much time, technical experience, and expensive reagents. The automated hematology analyzer (Sysmex SE-9000trade mark, TOA, Japan) equipped with the Immature Information (IMI) channel for immature myeloid cells can detect IMI(+) cells within 90 sec. Detection is made possible by the combination of a special reagent system and direct current/radiofrequency biosensors. We studied the relation of IMI(+) cells and variable cell counts with CD34(+) cell yield in autologous stem cell harvest. In a series of 32 patients (median age, 44 years; M:F = 11:21), 184 leukaphereses were performed after mobilization regimens with chemotherapy and G-CSF or G-CSF alone. Full blood cell counts were enumerated on peripheral blood (PB) samples taken prior to each leukapheresis. Mononuclear cell (MNC) and IMI(+) cell counts by automated hematology analyzer and flow cytometry based CD34(+) cell yield were measured on the harvested product. The relationship among PB white blood cells (WBC), PB monocytes, IMI(+) cells, MNC, and CD34(+) cell yield in a single leukapheresis was estimated by Pearson correlation analysis. PB WBC count showed no correlation with CD34(+) cell yield in a single leukapheresis (r = 0.02, P = 0.81). PB monocyte count showed a weak correlation (r = 0.21, P = 0.01) and MNC in harvest also showed a weak correlation (r = 0.36, P = 0.0001) with CD34(+) cell yield. In contrast, CD34(+) cell yield correlated well with IMI(+) cell count (r = 0.68, P = 0.0001), and data could be fitted by a linear regression equation, y = 0.330 + 0.974x. IMI(+) cell assay by the automated hematology analyzer correlated well with the CD34(+) cell yield in a mobilized autologous stem cell harvest. The IMI(+) cell count might be used as a simple and efficient indicator of blood stem cell mobilization and collection.

Adolescent↗
PubMed2001

One micrometer resolution NMR microscopy.

We obtained a magnetic resonance image of 1 microm resolution and 75 microm(3) voxel volume for a phantom filled with hydrocarbon oil within an hour at 14.1 T. For this work, a specially designed probe with a high sensitivity RF coil and gradient coils generating over 1000 G/cm was built. The optimal pulse sequence was analyzed in consideration of the bandwidth, diffusion coefficients, and T(1) and T(2) relaxations of the medium. The system was applied to the in vivo imaging of a geranium leaf stem to get the images of 2 microm resolution and 200 microm(3) voxel volume.

Magnetic Resonance Spectroscopy↗
PubMed2001

Intratumoral delivery of p2CMVmIL-12 using water-soluble lipopolymers.

Our objective was to design a water-soluble lipopolymer (WSLP) and an interleukin-12 (IL-12) expression plasmid for enhanced delivery of the IL-12 gene. We synthesized WSLP using branched polyethylenimine (PEI) of 1800 Da and cholesteryl chloroformate, and constructed p2CMVmIL-12, encoding the IL-12 subunits p35 and p40, each under the transcriptional control of a separate cytomegalovirus (CMV) promoter. The percentage of cholesterol conjugated to PEI was about 47% and the average molecular weight of WSLP was approximately 2000 Da. The mean particle size of WSLP/p2CMVmIL-12 complexes formulated in 5% glucose was 26 to 62 nm and xi potential was 8 to 60 mV. The WSLP/p2CMVmIL-12 complexes were nontoxic to CT-26 colon carcinoma cells at the N/P ratio (nitrogen atoms of WSLP/phosphate of plasmid DNA) of 20 and below; PEI25000/pDNA complexes were highly toxic. WSLP/p2CMVmIL-12 complexes demonstrated higher transfection in CT-26 cells compared with the DNA formulations prepared using PEI of molecular weights 1800, 10,000 and 25,000 Da. Transfection efficiency increased with an increase in N/P ratios from 5 to 15, then there was no significant increase in transfection up to the N/P ratio of 30/1. There was an increase in the level of IL-12 when free or complexed p2CMVmIL-12 was compared with free or complexed pIRESmIL-12 in which the p35 and p40 subunits were linked to the internal ribosome entry sites (IRES). At 48 hours post-injection of WSLP/p2CMVmIL-12 complexes into BALB/c mice bearing CT-26 subcutaneous tumors, the levels of IL-12, IFN-gamma, and nitric oxide (NO) in the supernatant of the cultured tumors were higher for the WSLP/p2CMVmIL-12 complexes than for the naked p2CMVmIL-12, WSLP, and 5% glucose injected groups. There was a significant improvement in the survival rate and the inhibition of tumor growth after a single injection of WSLP/p2CMVmIL-12 complexes. We have designed an effective, nontoxic WSLP and an IL-12 expression plasmid with two CMV promoters.

Animals↗
PubMed2001

Repression of GAD autoantigen expression in pancreas beta-Cells by delivery of antisense plasmid/PEG-g-PLL complex.

It was previously reported that silencing of the expression of glutamic acid decarboxylase (GAD) in transgenic nonobese diabetic (NOD) mice completely protected islet beta-cells against development of diabetes. This suggests that the repression of GAD autoantigen by somatic gene delivery can prevent autoimmune destruction of pancreatic beta-cells. To repress GAD expression in islet beta-cells, we delivered an antisense GAD mRNA expression plasmid (pRIP-AS-GAD) using poly(ethylene glycol)-grafted poly-L-lysine (PEG-g-PLL) as a gene carrier. In a gel retardation assay, the pRIP-AS-GAD/PEG-g-PLL complex was completely retarded above a weight ratio of 1:1.5 (plasmid: PEG-g-PLL). PEG-g-PLL protected the plasmid DNA from DNase I for more than 60 minutes. In a reporter gene transfection assay, PEG-g-PLL showed the highest transfection efficiency at a weight ratio of 1:3. We also transfected pRIP-AS-GAD/PEG-g-PLL complex into a GAD-producing mouse insulinoma (MIN6) cell line. The antisense mRNA was expressed specifically in beta-cells and expression was dependent on glucose level. The repression of GAD after transfection of pRIP-AS-GAD was confirmed by immunoblot assay. In addition, in vivo expression of antisense RNA in pancreas was confirmed by RT-PCR after intravenous injection of the complex into mice. Therefore, our study revealed that the pRIP-AS-GAD/PEG-g-PLL system is applicable for the repression of GAD autoantigen expression.

Animals↗
PubMed2001

Combined administration of plasmids encoding IL-4 and IL-10 prevents the development of autoimmune diabetes in nonobese diabetic mice.

Studies of animals with spontaneous autoimmune diabetes have revealed that autoreactive T cells that mediate islet beta-cell destruction belong to the Th1 subset (producing IL-2 and IFN-gamma), whereas regulatory T cells are Th2 type (producing IL-4 and IL-10). Here, we evaluate the effect of combined delivery of plasmid DNA encoding IL-4 and IL-10 using a degradable, cationic polymeric carrier, poly[gamma-(4-aminobutyl)-L-glycolic acid] (PAGA), in nonobese diabetic (NOD) mice. In the liver of NOD mice, we detected mouse Il4 and Il10 mRNA 5 days after intravenous injection of both PAGA-Il4 and PAGA-Il10 plasmid complexes. We found that 6 weeks after injection, 75% of observed islets were intact compared with less than 3% in the control group. Furthermore, in the treatment group, only 5% of the islets were severely infiltrated by the lymphocytes compared with over 30% in the control group. We measured glucose levels weekly up to the age of 32 weeks, revealing that co-injection of PAGA-Il4 and PAGA-Il10 plasmids prevented the development of diabetes in 75% of the treated animals. Thus, combined administration of mouse Il4 and Il10 plasmids prevents the development of autoimmune diabetes in NOD mice.

Animals↗
PubMed2001

Potential predictors of asymptomatic ischemic heart disease in patients with vasculogenic erectile dysfunction.

OBJECTIVES: To prospectively define the potential predictors of asymptomatic ischemic heart disease in patients with vasculogenic erectile dysfunction using a simple and practical method. Most patients with vasculogenic erectile dysfunction are known to have at least one significant cardiovascular risk factor. METHODS: After baseline evaluations, patients with erectile dysfunction of presumed vascular origin, who were older than 45 years and with no history of ischemic heart disease, were enrolled in the study. According to the results of repeated pharmacologic erection tests, we divided patients into responders and nonresponders. The cardiologic evaluations consisted of a comprehensive history taking, the assessment of cardiovascular risk factors, a physical examination, and an exercise treadmill test. RESULTS: A total of 97 patients completed the study. Fifteen (32.6%) of 46 responders and 25 (49.0%) of 51 nonresponders, respectively, had two or more cardiovascular risk factors (P = 0.101). Ischemic ST-segment changes on the exercise treadmill test were only observed in 8 nonresponders (15.7%) (P = 0.006). All these patients were older than 55 years, and seven had two or more cardiovascular risk factors, including hypertension. CONCLUSIONS: On the basis of these preliminary data, we suggest that cardiovascular evaluations may prove beneficial before prescribing sildenafil to patients with vasculogenic erectile dysfunction who are nonresponders to the pharmacologic erection test, are older than 55 years, and have two or more risk factors, including hypertension.

Age Factors↗
PubMed2001

Electromyographic activity of the biceps brachii muscle in shoulders with anterior instability.

PURPOSE: The purpose of this study was to evaluate the activity of the biceps muscle in the vulnerable abduction and external rotation position of the shoulder in patients with anterior instability. TYPE OF STUDY: This experimental study included a prospective analysis of the electromyographic (EMG) data on a group of patients with traumatic unilateral anterior instability of the shoulder. The EMG data of the unstable shoulders was compared with those of the opposite shoulders as control. The optimal sample size for the case-control study was calculated using an nQuery Advisor program (nQuery Advisor 3.0, Statistical Solutions, Cork, Ireland). METHODS: The EMG analyses were conducted in 76 shoulders in 38 patients who had a traumatic anterior instability in 1 shoulder. The EMG records were obtained at different positions of the shoulder, which included 0 degrees, 45 degrees, 90 degrees, and 120 degrees of shoulder abduction. In each angle of shoulder abduction, the arms were placed in an external rotation as tolerated by the anterior apprehension. The paired-sample t test was used to compare the difference of the root mean square (RMS) voltages between the stable and unstable shoulders in each degree of arm position. RESULTS: The RMS voltage of the biceps muscle was significantly greater in the unstable shoulder than the opposite stable shoulder in all positions of the arm (P =.00). The RMS voltage of the biceps was maximal at 90 degrees and 120 degrees of external rotation in the unstable shoulder (P <.05). The RMS voltage of the supraspinatus muscle revealed no differences in any of the test conditions (P =.904,.506,.119, and.781 in 0 degrees, 45 degrees, 90 degrees, and 120 degrees, respectively). CONCLUSIONS: In the vulnerable abduction and externally rotated position, the biceps muscle plays an active compensatory role in the unstable shoulder but not in the stable shoulder.

Adult↗
PubMed2001

Involvement of p38 mitogen-activated protein kinase and apoptosis signal-regulating kinase-1 in nitric oxide-induced cell death in PC12 cells.

Although nitric oxide (NO) plays key signaling roles in the nervous systems, excess NO leads to cell death. In this study, the involvement of p38 mitogen-activated protein kinase (p38 MAPK) and apoptosis signal-regulating kinase-1 (ASK1) in NO-induced cell death was investigated in PC12 cells. NO donor transiently activated p38 MAPK in the wild type parental PC12 cells, whereas the p38 MAPK activation was abolished in NO-resistant PC12 cells (PC 12-NO-R). p38 MAPK inhibitors protected the cells against NO-induced death, whereas the inhibitors were not significantly protective against the cytotoxicity of reactive oxygen species. Stable transfection with dominant negative p38 MAPK mutant reduced NO-induced cell death. Stable transfection with dominant negative mutant of ASK1 attenuated NO-stimulated activation of p38 MAPK and decreased NO-induced cell death. These results suggest that p38 MAPK and its upstream regulator ASK1 are involved in NO-induced PC12 cell death.

Animals↗
PubMed2001

Water-soluble and low molecular weight chitosan-based plasmid DNA delivery.

PURPOSE: Chitosan, a natural cationic polysaccharide, is a candidate non-viral vector for gene delivery because of its high positive charges and low cytotoxicity. In this study, low molecular weight chitosan (LMWC, molecular weight of 22 kDa) was characterized and evaluated as a gene carrier. METHODS: Plasmid/LMWC complex was analyzed in 1% agarose gel electrophoresis. To confirm that the LMWC protected plasmids from nuclease. DNase I protection assays were performed. pSV-beta-galactosidase plasmid/LMWC complex was transfected into 293T cells and transfection efficiency was evaluated by beta-galactosidase assay. Cytotoxicity of LMWC was determined by MTT assay. RESULTS: Unlike high molecular weight chitosan (HMWC), LMWC is highly water soluble, and can form complex with plasmids in physiological buffer. The plasmid DNA was completely retarded at a weight ratio of 1:2 (plasmid:LMWC) in 1% agarose gel. DNase I protection assay showed that plasmids were protected from DNase-I over 60 min. The most efficient transfection was obtained at a weight ratio of 1:3 (plasmid:LMWC). The transfection efficiency of LMWC was significantly higher than naked DNA and higher than poly-L-lysine (PLL). MTT assay showed that LMWC was less cytotoxic than PLL. CONCLUSIONS: LMWC is non-toxic and has higher transfection efficiency than PLL. Therefore, LMWC will be useful in the development of safe gene carriers.

Antineoplastic Agents↗
PubMed2001

Endogenous gastrin stimulates regeneration of remnant pancreas after partial pancreatectomy.

The purpose of this study was to evaluate the effect of endogenous gastrin on pancreatic regeneration after a partial pancreatectomy in the rat. Sixty rats were divided into 6 groups. Groups I and II received sham operation (splenectomy only), and groups III, IV, V, and VI received both 66% partial pancreatectomy (PPx) and splenectomy. Endogenous hypergastrinemia was induced in groups II, IV, and VI by gavage of Lansoprozole (LSP) for three weeks. In groups V and VI, gastrin receptor blocker, L365,260, was given continuously using an osmotic minipump. Following three weeks of treatment, PPx alone increased the pancreatic weight and protein content, but not RNA or DNA content (Group III). In the PPx groups, the pancreatic weight, and contents of protein, RNA, and DNA were significantly increased in the LSP treated rats (Group IV). This effect was abolished by L365,260 (Group VI). This results suggest that endogenous gastrin specifically stimulates regeneration of the remnant pancreas after partial pancreatectomy in rat. Induction of endogenous hypergastrinemia may be useful in patients following pancreatic resection for the prevention and treatment of pancreatic insufficiency.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Systemic administration of TerplexDNA system: pharmacokinetics and gene expression.

PURPOSE: The aim of this study is to extend our previous studies to investigate the TerplexDNA synthetic gene carrier system in pharmacokinetics, biodistribution, and gene expression in major organs after systemic administration. METHODS: The stability of the TerplexDNA system was analyzed in vitro with a serum incubation assay. The TerplexDNA PK/PD studies were conducted by quantitation of Terplex/radiolabeled DNA [CTP alpha-32P] complexes after rat-tail vein injection. The effect of the TerplexDNA system on gene expression in mouse major organs was analyzed by measuring luciferase activities after systemic administration. RESULTS: The TerplexDNA gene carrier showed significantly longer retention in the vascular space than naked plasmid DNA alone. At early time points (1 h postvenous injection), the lung was the major organ of the TerplexDNA distribution, followed by the liver as a major distribution organ at later time points (24 h postinjection). The major organs of transgene expression after intravenous injection were the liver and heart. CONCLUSION: The TerplexDNA system has the potential for in vivo applications due to its higher bioavailability of plasmid DNA in the tissues, and due to its organ specific distribution.

Algorithms↗
PubMed2001

In situ study of insulin aggregation induced by water-organic solvent interface.

PURPOSE: The aim of this study was to assess insulin stability by monitoring in situ time-course of insulin aggregation induced by a water-organic solvent (o/w) interface that occurs during the microencapsulation process. METHODS: Insulin aggregation at a simple o/w interface was monitored spectrophotometrically by detecting the percentage of turbidity changes (%T) at 350 nm. The effects of protein concentration and agitation and the presence of poly (lactic-co-glycolic acid) (PLGA) in methylene chloride (MC) on insulin aggregation were observed. For the 0.72 mg/ml insulin in phosphate-buffered saline (PBS), the effect of nonionic (dodecyl maltoside [DDM]) and anionic (sodium dodecyl sulfate [SDS]) surfactant in PBS were also evaluated at various protein/surfactant mol ratios. The conformation of insulin protected by a 10-fold molar excess of SDS recovered after 1 h of contact with MC was evaluated via circular dichroism (CD) spectroscopy. RESULTS: A typical turbidity-time profile was represented by a sigmoidal curve. Greater change in %T was observed with increasing insulin concentration, in the presence of PLGA in MC and in the presence of agitation. DDM failed to delay insulin aggregation at all ratios used, whereas a less than 10% change in %T was observed in 1 h when a 10- - approximately 20-fold excess of SDS was used. CD spectra indicated that the presence of insulin in SDS after 1 h of contact with MC qualitatively retained its secondary structure integrity. CONCLUSIONS: An experimental method was designed for an in situ assessment of protein stability at the o/w interface.

Chemical Phenomena↗
PubMed2001

A case of kleptomania and compulsive sexual behavior treated with naltrexone.

Objective of this paper was to examine a possible treatment option for two disorders currently lacking agreed upon pharmacotherapeutic interventions. We report a patient fulfilling DSM-IV criteria for kleptomania with comorbid compulsive sexual behavior who failed to respond to fluoxetine, behavioral therapy, and psychotherapy, and who was therefore treated with naltrexone to reduce urges to steal and sexual urges. Treatment with high-dose naltrexone (150 mg/day) led to remission of both the patient's urges to steal and sexual urges. Discontinuation and rechallenge with the medication provides further support that improvement was due to naltrexone. Naltrexone in high doses show promise for the treatment of both kleptomania and compulsive sexual behavior.

Compulsive Behavior↗
PubMed2001

Changes of biophysical properties of the skin measured by non-invasive techniques after Q-switched Nd-YAG laser therapy in patients with nevus of Ota.

BACKGROUND/AIMS: The aim of the study was to objectify the effect of a Q-switched Nd-YAG laser on Ota's nevus in view of barrier function, surface contour changes, dermal blood flow, surface color changes and sebum production rate. METHODS: Fifteen Korean patients with nevus of Ota (between 14 and 54 years of age) were enrolled. All the patients were treated by Q-switched Nd-YAG laser and followed up for 12 weeks. A reflectance spectrophotometer, a colorimeter, laser Doppler flowmetry, a Tewameter, a Corneometer and a Sebumeter were used to make measurements. RESULTS: Pvalues of less than 0.05 were regarded as statistically significant. In skin reflectance measurements, L* values declined for 4 weeks and increased at 12 weeks, indicating that the brightness of the lesions improved. a* values showed a significant increase at 2 and 4 weeks. On the contrary, b* values decreased at 2 weeks. Transepidermal water loss and dermal blood flux showed identical patterns, showing increases at 2 weeks. The water holding capacity decreased at 2 and 4 weeks, and thereafter showed a delayed recovery. Casual sebum production increased at 4, 8 and 12 weeks. The loss of skin roughness was observed at 4 weeks, recovering at 12 weeks, although statistically insignificant. Reflex spectrophotometry did not reflect the changing properties of the skin. CONCLUSIONS: Our data suggest a useful model for evaluating physiologic skin changes after laser surgery in patients with nevus of Ota.

Adolescent↗
PubMed2001

Augmentation of myocardial transfection using TerplexDNA: a novel gene delivery system.

Gene therapy is a potential new strategy for the treatment of cardiovascular disease. The most efficacious method of gene delivery remains a key hurdle to effective gene therapy. We present the application of a novel, nonviral gene delivery system (TerplexDNA) to augment myocardial transfection. The hearts of New Zealand white rabbits were injected with reporter genes, luciferase cDNA or beta-galactosidase cDNA, either as naked plasmid DNA or plasmid DNA complexed with stearyl-poly(L-lysine)-low density lipoprotein (TerplexDNA). Three day left heart myocardial cell lysates produced 44571 +/- 8730 RLU (RLU = total light units/mg protein) for the TerplexDNA luciferase rabbits versus 1638 +/- 567 RLU for the naked luciferase rabbits (P = 0.002). Thirty days after injection, myocardial lysates produced 677 +/- 52 RLU for the TerplexDNA luciferase hearts versus 18 +/- 3 RLU for the naked luciferase hearts (P = 0.002). Histologic analysis of the hearts transfected with beta-galactosidase showed that TerplexDNA increased the area and depth of transfection compared with the naked plasmid DNA alone. The hearts of Sprague-Dawley rats were injected in a similar fashion and analyzed at 1, 3, 5, 10, 15, 25 and 30 days after injection. The naked luciferase injected hearts showed transient elevation of luciferase activity to day 5 but fell back to baseline levels after that time-point. The TerplexDNA luciferase injected hearts had significantly elevated luciferase activity to 30 days. The Terplex gene delivery system significantly augments myocardial transfection compared with a naked plasmid DNA system alone. The advantage in transfection efficiency appears to be related to the unique properties of the TerplexDNA carrier molecule. The TerplexDNA delivery system represents a novel means to augment transfection of the myocardium.

Animals↗