• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.33-40
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• 2001

The aim of present study was to define the cellular mechanisms underlying changes in delayed rectifier $K^+\;(K_{DR})$ channel function in isoproterenol-induced hypertrophy. It has been proposed that $K_{DR}$ channels play a role in regulation of vascular tone by limiting membrane depolarization in arterial smooth muscle cells. The alterations of the properties of coronary $K_{DR}$ channels have not been studied as a possible mechanism for impaired coronary reserve in cardiac hypertrophy. The present study was carried out to compare the properties of coronary $K_{DR}$ channels in normal and hypertrophied hearts. These channels were measured from rabbit coronary smooth muscle cells using a patch clamp technique. The main findings of the study are as follows: (1) the $K_{DR}$ current density was decreased without changes of the channel kinetics in isoproterenol-induced hypertrophy; (2) the sensitivity of coronary $K_{DR}$ channels to 4-AP was increased in isoproterenol-induced hypertrophy. From the above results, we suggest for the first time that the alteration of $K_{DR}$ channels may limit vasodilating responses to several stimuli and may be involved in impaired coronary reserve in isoproterenol-induced hypertrophy.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.1
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• pp.35-42
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• 2015

In cardiovascular disorders, understanding of endothelial cell (EC) function is essential to elucidate the disease mechanism. Although the mouse model has many advantages for in vivo and in vitro research, efficient procedures for the isolation and propagation of primary mouse EC have been problematic. We describe a high yield process for isolation and in vitro culture of primary EC from mouse arteries (aorta, braches of superior mesenteric artery, and cerebral arteries from the circle of Willis). Mouse arteries were carefully dissected without damage under a light microscope, and small pieces of the vessels were transferred on/in a Matrigel matrix enriched with endothelial growth supplement. Primary cells that proliferated in Matrigel were propagated in advanced DMEM with fetal calf serum or platelet-derived serum, EC growth supplement, and heparin. To improve the purity of the cell culture, we applied shearing stress and anti-fibroblast antibody. EC were characterized by a monolayer cobble stone appearance, positive staining with acetylated low density lipoprotein labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate, RT-PCR using primers for von-Willebrand factor, and determination of the protein level endothelial nitric oxide synthase. Our simple, efficient method would facilitate in vitro functional investigations of EC from mouse vessels.

• Progress in Medical Physics
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• v.33 no.4
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• pp.88-100
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• 2022

Purpose: Cerebral microbleeds are more susceptible than surrounding tissues and have been associated with a variety of neurological and neurodegenerative disorders that are indicative of an underlying vascular pathology. We investigated relaxivity changes and microvascular indices in the presence of microbleeds in an imaging voxel by evaluating those before and after contrast agent injection. Methods: Monte Carlo simulations were run with a variety of conditions, including different magnetic field strengths (B₀), different echo times, and different contrast agents. ΔR2^* and ΔR2 and microvascular indices were calculated with varying microvascular vessel sizes and microbleed loads. Results: As B₀ and the concentration of microbleeds increased, 𝜟R2^* and 𝜟R2 increased. 𝜟R2^* increased, but 𝜟R2 decreased slightly as the vessel radius increased. When the vessel radius was increased, the vessel size index (VSI) and mean vessel diameter (mVD) increased, and all other microvascular indices except mean vessel density (Q) increased when the concentration of microbleeds was increased. Conclusions: Because patients with neurodegenerative diseases often have microbleeds in their brains and VSI and mVD increase with increasing microbleeds, microbleeds can be altered microvascular signals in a voxel in the brain of a neurodegenerative disease at 3T magnetic resonance imaging.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.136-144
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• 2007

Biotae Orientalis has been widely used for treatment of relaxion of smooth muscle, gastrointestinal hemorrhage and alopecia in Oriental Medicine. This experiment examined the effect of an extracts, obtained from the acetone and MeOH extracts of dried or fresh Biotae Orientalis, on hair growing activity of the C57BL/6N mice after topical application to skin. First, We examined on hair growth activity of extracts of Biotae Orientalis compare to control and 1% minoxidil groups. Second, We investigated on the number of hair follicle and mast cells after topical application of extracts of the Biotae Orientalis to skin for 16 day. Third, We investigated immunoreactive density of vascular endothelial growth factor(VEGF), protein kinase C-${\alpha}$(PKC-${\alpha}$) and stem(mast) cell factor(SCF) in skin of C57BL/6N mice by immunohistochemical methods. I fourth investigated changes of subpopulation of splenocytes and thymocytes in C57BL/6N mice for 16day using laser flow cytometry. The results were as follows : Hair growing effect of acetone and MeOH extracts of dried and fresh Biotae Orientalis was observed in 70%, 90% and 60% in hair removed skin area in 16 day respectively. Immunoreactive density of VEGF and PKC-${\alpha}$ in skin of experimental groups was weakly stained compare to control group in 10 day. Immunoreactive density of stem cell factor in skin of experimental group was heavily stained compare to control group in 10 day. Splenic TH/TC Iymphocytes of lived MeOH extracts group significantly increased compare to control group. TH cells in thymic T lymphocytes were increased compare to control group. These experiment suggest that acetone and MeOH extracts of Biotae Orientalis may be used for topical treatment of alopecia areata.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.778-790
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• 2008

This experiment investigated the effect of mixed extracts obtained from Mylabris phalerata Pall. and Drynariae Rhizoma on hair growth activity of the normal and spontaneous alopecia areata model of C57BL/6N mice for 16 days. First, we examined morphological regrowth of hair in normal and spontaneous alopecia model of C57BL/6N mice. Second, we examined immunoreactive density of vascular endothelial growth factor(VEGF), c-kit and protein kinase $C-{\alpha}(PKC-{\alpha})$ in skin of normal C57BL/6N mice by immunohistochemical methods. Third, we investigated expression of $TGF-{\beta}$, prolactin and placenta lactogen after topical application of mixed extracts of Mylabris phalerata Pall. and Drynariae Rhizoma to skin by RT-PCR. The results were as follows: Hair growth effect from middle and high concentration of mixed extracts of Mylabris phalerata Pall. and Drynariae Rhizoma was observed in 80% of normal mice in whose hair had been clipped in 15th days. Hair growth effect of all concentrations of mixed extracts of Mylabris phalerata Pall. and Drynariae Rhizoma was observed in 100% of spontaneous alopecia model of C57BL/6N mice in 15th days. Immunoreactive density of VEGF, c-kit and $PKC-{\alpha}$ in skin of all concentrations of mixed extracts of Mylabris phalerata Pall. and Drynariae Rhizoma were strongly stained in epidermis, bulge, secondary hair germ cells and cutaneous trunci m. compare to control group in 10th day. In experimental III group, Immunoreactive density of VEGF, c-kit and $PKC-{\alpha}$ in skin were strongly stained in inner and outer root sheath of skin. The treatment of mixed extracts of Mylabris phalerata Pall. and Drynariae Rhizoma increased the expression of $TGF-{\beta}$, placenta lactogen and prolactin in the skin of normal C57BL/6N mice compared to control group. These experiments suggest that mixed extracts of Mylabris phalerata Pall. and Drynariae Rhizoma may stimulate the topical hair growth activity and it can be useful for treatment of alopecia areata.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.509-518
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• 2010

Purpose: Major drawbacks of conventional bone marrow stromal cells (BSCs) transplantation method are mainly caused by direct transplanted cell to host cell interactions. We hypothesized that separation of the transplanted cells by a microporous membrane might inhibit most of the potential adverse effects and induce superior effect. The purpose of the study is to determine the optimal condition of the microporous membrane. Methods: First, BSCs were placed in polyethylene terephthalate (PET) transwell inserts with 3, 8, or $12{\mu}m$ pore size, and cultured in 24 well culture plates. After 5 days, bottoms of the plates were observed for presence of attached BSCs in monolayer and cell numbers were evaluated. Second, BSCs were placed PET, polycarbonate (PCT), and mixed cellulose esters (MCE) transwell inserts with 3 and $8{\mu}m$ pore size, and cultured in 24 well culture plates. After 3 days, the supernatants of the media left in culture plate were analyzed for collagen, vascular endothelial growth factor (VEGF), platelet derived growth factor BB (PDGF-BB), and basic fibroblast growth factor (bFGF). Third, BSCs were placed in 15% and 70% of the PET membrane with $3{\mu}m$ pore size. All the experimental conditions and methods were same as the second study. Results: The optimal pore sizes to prevent BSC leakage were $3{\mu}m$ and $8{\mu}m$. The amounts of type I collagen and three growth factors tested did not show significant differences among PET, PCT, and MCE groups. However, the collagen, VEGF, and bFGF levels were much higher in the high (70%) density group than in the low (15%) density group. Conclusion: This study revealed that the optimal pore size of membrane to prevent direct BSC to recipient cell contact is in between $3{\mu}m$ and $8{\mu}m$. Membrane materials and pore sizes do not influence the collagen and growth factor passage through the membrane. The most striking factor for collagen and growth factor transport is pore density of the membrane.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.281-287
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• 2011

Objective : Pituitary apoplexy is life-threatening clinical syndrome caused by the rapid enlargement of a pituitary tumor due to hemorrhage and/or infarction. The pathogenesis of pituitary apoplexy is not completely understood. We analyzed the magnetic resonance imaging (MRI) of pituitary tumors and subsequently correlated the radiological findings with the clinical presentation. Additionally, immunohistochemistry was also performed to determine whether certain biomarkers are related to radiological apoplexy. Methods : Thirty-four cases of pituitary adenoma were enrolled for retrospective analysis. In this study, the radiological apoplexy was defined as cases where hemorrhage, infarction or cysts were identified on MRI. Acute clinical presentation was defined as the presence of any of the following symptoms: severe sudden onset headache, decreased visual acuity and/or visual field deficit, and acute mental status changes. Angiogenesis was quantified by immunohistochemical expression of fetal liver kinase 1 (Flk-1), neuropilin (NRP) and vascular endothelial growth factor (VEGF) expression, while microvascular density (MVD) was assessed using Endoglin and CD31. Results : Clinically, fourteen patients presented with acute symptoms and 20 for mild or none clinical symptoms. Radiologically, fifteen patients met the criteria for radiological apoplexy. Of the fifteen patients with radiologic apoplexy, 9 patients presented acute symptoms whereas of the 19 patient without radiologic apoplexy, 5 patients presented acute symptoms. Of the five biomarkers tracked, only VEGF was found to be positively correlated with both radiological and nonradiological apoplexy. Conclusion : While pituitary apoplexy is currently defined in cases where clinical symptoms can be histologically confirmed, we contend that cases of radiologically identified pituitary hemorrhages that present with mild or no symptoms should be designated subacute or subclinical apoplexy. VEGF is believed to have a positive correlation with pituitary hemorrhage. Considering the high rate of symptomatic or asymptomatic pituitary tumor hemorrhage, additional studies are needed to detect predictors of the pituitary hemorrhage.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1715-1720
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• 2013

Background: The discovery that microRNAs (miRNAs) regulate proliferation, invasion and metastasis provides a principal molecular basis of tumor heterogeneity. Microvessel distribution is an important characteristic of solid tumors, with significant hypoxia occurring in the center of tumors with low blood flow. The distribution of miR-374a in breast tumors was examined as a factor likely to be important in breast cancer progression. Methods: Breast tissue samples from 40 patients with breast cancer were classified into two groups: a highly invasive and metastatic group (HIMG) and a low-invasive and metastatic Group (LIMG). Samples were collected from the center and edge of each tumor. In each group, six specimens were examined by microRNA array, and the remaining 14 specimens were used for real-time RT-qPCR, Western blot and immunohistochemical analyses. Correlation analysis was performed for the miRNAs and target proteins. Follow-up was carried out during 28 months to 68 months after surgery, and survival data were analyzed. Results: In the LIMG, the relative content of miR-374a was lower in the center of the tumor than at its edge; in the HIMG, it was lower at the edge of the tumor, and miR-374a levels were lower in breast cancer tissues than in normal tissues. There was no difference between VEGF-A and VCAM-1 mRNA levels at the edge and center of the tumor; however, we observed a significant difference between VEGF-A and VCAM-1 protein expression levels in these two regions. There was a negative correlation between miR-374a and target protein levels. The microvessel density (MVD) was lower in the center of the tumor than at its edge in HIMG, but the LIMG vessels were uniformly distributed. There was a significant positive correlation between MVD and the number of lymph node metastases (Pearson correlation, r=0.912, P<0.01). The median follow-up time was 48.5 months. LIMG had higher rate of disease-free survival (100%, P=0.013) and longer median survival time (66 months) than HIMG, which had a lower rate of 75% and shorter median survival time (54 months). Conclusions: Our data demonstrated miR-374a to be differentially distributed in breast cancer; VEGF-A and VCAM-1 mRNA had coincident distribution, and the distribution of teh respective proteins was uneven and opposite to that for the miR-374a. These data might explain the differences in the distribution of MVD in breast cancer and variation in breast cancer prognosis.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.1
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• pp.71-87
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• 1995

The purpose of this study was to investigate the early irradiation changes on the ultrastructure of the capillary endothelial cell in the rat submandibular glands. For the study, 110 Sprague-Dawley strain male rats were singly irradiated to their neck regions with the doses of 2Gy, 5Gy, and 10Gy by 6MV X -irradiation, and sacrificed on the 3 hours, 6 hours, 12 hours, 1 day, 3 days, 7 days, and 14 days after irradiation. The authors observed the histologic and ultrastructural changes of the capillary endothelial cell using the light and electron microscopes. The results were as follows: I. In the light microscopic examination, the capillary dilation was observed on the 6 hours group and the capillary density was slightly increased on the 12 hours group after 2Gy and 5Gy irradiation. And luminal size and capillary density were decreased on the 3 days and the 7 days groups after irradiation, after then, they were recovered. But capillary density was still decreased on the 14 days group after 10Gy irradiation. 2. In the transmission electron microscopic examination, the mild proliferation of cytoplasmic process of the endothelial cell and reduction in luminal size were observed on the 3 hours group after irradiation. After then, endothelial swelling, marked proliferation of cytoplasmic process, thickened basal lamina, and numerous pinocytotic vesicles were observed after the 1 day group after irradiation. Thickened basal lamina and numerous pinocytotic vesicles were still observed until the 7 days group after irradiation. These changes were recovered to normal on the 14 days group after 2Gy and 5Gy irradiation, but not after 10Gy irradiation. 3. In the scanning electron microscopic examination, the dilation of conduits and constriction, and meandering were observed on the 1 day group after 10Gy irradiation. These changes were observed with increased coarseness of the surface of the vascular resin casting on the 3 days group after irradiation. 4. From the above results, endothelial swelling, proliferation of cytoplasmic process, and thickening of the basal lamina appeared before the 6 hours group after irradiation. And these changes may also induce the increase of the capillary number and luminal size, after then, capillary permeability was increased via the increase of the number of pinocytotic vesicles. The changes were observed earlier and more apparent with the increase of the irradiation doses under the dose of 10Gy irradiation.

• Journal of Korean Neurosurgical Society
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• v.57 no.2
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• pp.88-93
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• 2015

Objective : Elevated cellular retinoic acid binding protein-I (CRABP-I) is thought to be related to the abnormal proliferation and migration of smooth muscle cells (SMCs). Accordingly, a higher CRABP-I level could cause disorganized vessel walls by causing immature SMC phenotypes and altering extracellular matrix proteins which could result in vulnerable arterial walls with inadequate responses to hemodynamic stress. We hypothesized that elevated CRABP-I level in the cerebrospinal fluid (CSF) could be related to subarachnoid hemorrhage (SAH). Moreover, we also extended this hypothesis in patients with vascular malformation according to the presence of hemorrhage. Methods : We investigated the CSF of 26 patients : SAH, n=7; unruptured intracranial aneurysm (UIA), n=7; arteriovenous malformation (AVM), n=4; cavernous malformation (CM), n=3; control group, n=5. The optical density of CRABP-I was confirmed by Western blotting and presented as mean${\pm}$standard error of the measurement. Results : CRABP-I in SAH ($0.33{\pm}0.09$) was significantly higher than that in the UIA ($0.12{\pm}0.01$, p=0.033) or control group ($0.10{\pm}0.01$, p=0.012). Hemorrhage presenting AVM (mean 0.45, ranged 0.30-0.59) had a higher CRABP-I level than that in AVM without hemorrhage presentation (mean 0.16, ranged 0.14-0.17). The CRABP-I intensity in CM with hemorrhage was 0.21 and 0.31, and for CM without hemorrhage 0.14. Overall, the hemorrhage presenting group (n=11, $0.34{\pm}0.06$) showed a significantly higher CRABP-I intensity than that of the non-hemorrhage presenting group (n= 10, $0.13{\pm}0.01$, p=0.001). Conclusion : The results suggest that elevated CRABP-I in the CSF could be related with aneurysm rupture. Additionally, a higher CRABP-I level seems to be associated with hemorrhage development in vascular malformation.