Elevated extracellular calcium ions promote proliferation and migration of mesenchymal stem cells via increasing osteopontin expression

Lee, Mi Nam,Hwang, Hee-Su,Oh, Sin-Hye,Roshanzadeh, Amir,Kim, Jung-Woo,Song, Ju Han,Kim, Eung-Sam,Koh, Jeong-Tae Nature Publishing Group UK 2018 Experimental and molecular medicine Vol.50 No.11

<▼1><P>Supplementation of mesenchymal stem cells (MSCs) at sites of bone resorption is required for bone homeostasis because of the non-proliferation and short lifespan properties of the osteoblasts. Calcium ions (Ca<SUP>2+</SUP>) are released from the bone surfaces during osteoclast-mediated bone resorption. However, how elevated extracellular Ca<SUP>2+</SUP> concentrations would alter MSCs behavior in the proximal sites of bone resorption is largely unknown. In this study, we investigated the effect of extracellular Ca<SUP>2+</SUP> on MSCs phenotype depending on Ca<SUP>2+</SUP> concentrations. We found that the elevated extracellular Ca<SUP>2+</SUP> promoted cell proliferation and matrix mineralization of MSCs. In addition, MSCs induced the expression and secretion of osteopontin (OPN), which enhanced MSCs migration under the elevated extracellular Ca<SUP>2+</SUP> conditions. We developed in vitro osteoclast-mediated bone resorption conditions using mouse calvaria bone slices and demonstrated Ca<SUP>2+</SUP> is released from bone resorption surfaces. We also showed that the MSCs phenotype, including cell proliferation and migration, changed when the cells were treated with a bone resorption-conditioned medium. These findings suggest that the dynamic changes in Ca<SUP>2+</SUP> concentrations in the microenvironments of bone remodeling surfaces modulate MSCs phenotype and thereby contribute to bone regeneration.</P></▼1><▼2><P><B>Bone formation: released calcium could stimulate stem cells</B></P><P>Studies with mouse cells and bone samples indicate how calcium ions released during the normal turnover of bone promote the supplementation of stem cells needed to make new bone during routine “remodeling” and regeneration after injury. Our bones are degraded and remodeled continuously, requiring the controlled supplement of stem cells that create bone-forming cells called osteoblasts. Jeong-Tae Koh and colleagues at Chonnam National University, Gwangju, South Korea, exposed the relevant stem cells to increased concentrations of external calcium ions. This promoted cell proliferation and migration that allow the cells to support new bone formation. The research suggests this effect on stem cells may be achieved by calcium ions released directly from bone as it is naturally degraded. The findings may help researchers develop new ways to encourage bone regeneration after injury and surgery.</P></▼2>

주물공장 근로자에서 발생한 국한성 석면폐증 1예

김태우,고동희,김민기,유승원,류향우,한정희,정순희 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.2

배경: 주물공장 근로자에서 발생한 석면폐증의 작업 관련성을 평가하고 그 증례를 보고하고자 한다. 증례: 30년간 주물공장에서 근무한 환자로 인후통, 기침, 노란 가래가 있어 검사한 결과 결핵이 의심되어 치료 하였으며, 치료 중 석면폐증으로 진단되었다. 작업 관련성 평가를 위해 실시한 폐 조직의 조직학적 검사에서 1 cm^(2)당 3개의 석면소체가 발견되었고, 투과전자현미경으로 분석한 석면 함유량은 23.26x10^(6) fibers/g이었다. 결론: 작업환경조사, 폐 조직의 석면 분석 등을 통해 작업 관련성이 높다고 판단하였다. Background: Foundry workers are known to be exposed to silica and have an increased risk of Silicosis. There are also reports that state these foundry workers were associated with asbestos-related change in the X-ray results of the lungs. This report discusses a case of localized asbestosis developed in a foundry worker who worked in 12 Korean foundries. Case report: A 49-year-o1d man who worked at molding and melting for 30 years, Presented with sore throat, cough and yellow sputum for 1 month. From physical and clinical examination, Pulmonary tuberculosis was highly suspicious; therefore, he was medicated for 6 months. After tuberculosis medication, the radiological finding was reactivation of tuberculosis, and an asbestos body was detected at a trans-bronchial lung biopsy. During an operation, operators found multiple palpable masses and bullae 10calized in the right upper lobe (RUL) and performed right upper lobectomy and right middle lobe wedge resection. Using hematoxylin-eosin stain and iron stain, we could detect asbestos bodies by light microscopy. We analyzed the asbestos fiber burden in dry lung tissue by transmission electron microscopy with energy dispersive X-ray spectrometer (TEM-EDX). The fiber type was chrysotile and the fiber burden was 23.26 x 10^(6) fiber/g dry lung. Discussion: This case study of a foundry worker with localized asbestosis is uncommon in Korea. We found an occupational relationship between the foundry worker and localized asbestosis through various investigative techniques such as measurements taken at his working environment, clinical, radiological and pathological examination of the foundry worker and mineralogical examination of the asbestos fiber.

치근 천공 치료 재료의 생체친화성의 비교

강민경,배인호,고정태,황윤찬,황인남,오원만 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.3

This study was carried out in order to determine in vitro biocompatibility of white mineral trioxide aggregate (MTA), and to compare it with that of the commonly used materials, i. e. calcium hydroxide liner(Dycal), glass ionomer cement (GIC), and Portland cement which has a similar composition of MTA. To assess the biocompatibility of each material, cytotoxicity was examined using MG-63 cells. The degree of cytotoxicity was evaluated by scanning electron microscopy (SEM) and a colorimetric method, based on reduction of the tetrazolium salt 2,3 bis {2methoxy 4nitro 5〔(sulfenylamino) carbonyl〕2H tetrazolium hydroxide} (XTT) assay. The results of SEM revealed the cells in contact with GIC, MTA, and Portland cement at 1 and 3 days were apparently healthy. In contrast, cells in the presence of Dycal appeared rounded and detached. In XTT assay, the cellular activities of the cells incubated with all the test materials except Dycal were similar, which corresponded with the SEM observation. The present study supports the view that MTA is a very biocompatible root perforation repair material. It also suggests that cellular response of Portland cement and GIC are very similar to that of MTA. 이번 연구는 치근 천공의 치료 재료인 white mineral trioxide aggregate (MTA)를 흔히 사용되는 calcium hydroxideliner(Dycal^(R), glass ionomer cement (GIC), 그리고 MTA와 유사한 성분을 가진 Portland cement와 세포독성 실험으로 생체 친화성을 평가하는 것이다. 세포독성의 정도는 MG-63 세포를 이용해 주사전자 현미경적 관찰과 수용성 tetrazolium salt를 이용한 흡광도를 측정 (XTT assay)하여 평가하였다. SEM 관찰에서, 1일과 3일째 모두에서 GIC와 MTA, Portland cement표면에서는 잘 부착된 세포를 보여주었다. 반면에, Dycal 표면의 세포들은 둥글고 부착되지 않은 양상을 보여주었다. XTT assay에서는 Dycal을 제외한 모든 재료에서 유사하게 높은 세포 활성도를 보여주었으며, 이는 SEM 관찰 소견과 일치하였다. 이번 연구는 MTA가 생체친화적인 재료라는 견해를 뒷받침한다. 또한 Portland cement와 GIC에서도 MTA와 유사한 세포반응을 보여주었다.

급성 말초 동맥 폐색증의 치료

박형준,박연고,고영환,서태석,이운기,박홍규,백정흠,이정남,정민,이영돈,민승기 대한혈관외과학회 2003 Vascular Specialist International Vol.19 No.1

재발성 류마티즘 환자에서 발작의 유발인자

주유철,이동민,양종태,신병철,임태영,서정균,정기영,최동헌,김원,조영신,고희관 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.2

Background and Objectives : Palindromic rheumatism (PR) is known to be triggered without any obviously inciting events in most patients, although, in a few cases, attacks have been noted to relate to another events such as weather change, childbirth, ingestion of certain foods, or over-exercise. The aim of this study was to characterize the triggering factors on palindromic attacks. Materials and Methods : We evaluated sixty-four patients with PR for the presence of triggering factors and the relationship between attacks and triggering factors by interview of patients. We considered that there was an probable association between episodes and PR, if episodes within 24 hours prior to PR had triggered at least 50% of all attacks and a definite association between episodes and PR, if episodes within 24 hours prior to PR had triggered 100% of all attacks. Results : In 15 patients (35.9%), there was a possible association between episodes of PR and initiating events. In 8 patients (12.5%), there was a definite association between episodes of PR and initiating events. The triggering factors were physical over-activity including exercise (19/64: 29.7%), foods, such as rawfish, crab, and chicken, including alcohol (19/96: 19.8%). However, there were no difference between the groups with and without the triggering factor in sex ratio, duration and onset of PR, the positive rate of rheumatoid factor and involved sites. Conclusion : Our observations showed that PR was triggered by physical over-activity more than in previous reports and hypersensitivity to foods was a causative factor in some patients with PR. However, patients with triggering factors had a similiar clinical profile to patients without triggering factors.

Natriuresis Induced by Intracerebroventricular Diazepam in Rabbits

Jeong-Tae Koh,Young-Johng Kook 대한생리학회-대한약리학회 1998 The Korean Journal of Physiology & Pharmacology Vol.2 No.5

<P> The renal function is under regulatory influence of central nervous system (CNS), in which various neurotransmitter and neuromodulator systems take part. However, a possible role of central GABA- benzodiazepine system on the central regulation of renal function has not been explored. This study was undertaken to delineate the renal effects of diazepam. Diazepam, a benzodiazepine agonist, administered into a lateral ventricle (<I>icv</I>) of the rabbit brain in doses ranging from 10 to 100 ㄍg/kg, elicited dose-related diuresis and natriuresis along with improved renal hemodynamics. However, when given intravenously, 100 ㄍg/kg diazepam did not produce any significant changes in all parameters of renal function and systemic blood pressure. Diazepam, 100 ㄍg/kg <I>icv</I>, transiently decreased the renal nerve activity (RNA), which recovered after 3 min. The plasma level of atrial natriuretic peptide (ANP) increased 7-fold, the peak coinciding with the natriuresis and diuresis. Muscimol, a GABAergic agonist, 1.0 ㄍg/kg given <I>icv</I>, elicited marked antidiuresis and antinatriuresis, accompanied by decreases in systemic blood pressure and renal hemodynamics. When <I>icv</I> 0.3 ㄍg/kg muscimol was given 3 min prior to 30 ㄍg/kg of diazepam <I>icv</I>, urinary flow and Na excretion rates did not change significantly, while systemic hypotension was produced. These results indicate that <I>icv</I> diazepam may bring about natriuresis and diuresis by influencing the central regulation of renal function, and that the renal effects are related to the increased plasma ANP levels, not to the decreased renal nerve activity, and suggest that the effects may not be mediated by the activation of central GABAergic system.

Influence of the Central Benzodiazepinergic System on Peripheral Cardiovascular Regulation

Jeong-Tae Koh,Jeong-Min Ju,Dong-Ho Shin,Han-Ho Cho,Bong-Kyu Choi,Jae-Ha Kim 대한생리학회-대한약리학회 1998 The Korean Journal of Physiology & Pharmacology Vol.2 No.3

<P> Diazepam is known to have cardiovascular depressive effects through a combined action on benzodiazepinergic receptor and the GABA receptor-chloride ion channel complex. Moreover, it is known that barbiturates also have some cardiovascular regulatory effects mediated by the central GABAergic system. Therefore, this study was undertaken to delineate the regulatory actions and interactions of these systems by measuring the responses of the cardiovascular system and renal nerve activity to muscimol, diazepam and pentobarbital, administered intracerebroventricularly in rabbits. When muscimol (0.03∼0.3 ㄍg/kg), diazepam (10∼100 ㄍg/kg) and pentobarbital (1∼10 ㄍg/kg) were injected into the lateral ventricle of the rabbit brain, there were similar dose-dependent decreases in blood pressure (BP) and renal nerve activity (RNA). The relative potency of the three drugs in decreasing BP and RNA was muscimol > pentobarbital > diazepam. Muscimol and pentobarbital also decreased the heart rate in a dose-dependent manner; however, diazepam produced a trivial, dose-independent decrease in heart rate. Diazepam (30 ㄍg/kg) augmented the effect of muscimol (0.1 ㄍg/kg) in decreasing blood pressure and renal nerve activity, but pentobarbital (3 ㄍg/kg) did not. Bicuculline (0.5 ㄍg/kg), a GABAergic receptor blocker, significantly attenuated the effect of muscimol in decreasing BP and RNA, either alone or with diazepam, and that of pentobarbital in decreasing BP and RNA, either alone or with muscimol. We inferred that the central benzodiazepinergic and barbiturate systems help regulate peripheral cardiovascular function by modulating the GABAergic system, which adjusts the output of the vasomotor center and hence controls peripheral sympathetic tone. Benzodiazepines more readily modulate the GABAergic system than barbiturates.

The Role of the Carbon Framework in Sulfur-Carbon Composite Cathodes in Li-S Batteries

Koh, Jeong Yoon,Kim, Seok,Park, Min-Sik,Yang, Hye Jeong,Yang, Tae Hyun,Jung, Yongju Pergamon Press 2016 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>Lithium-sulfur (Li-S) batteries are considered a promising energy storage solution for today’s society, which faces significant energy and environmental issues. Successful implementation of Li-S batteries requires the development of a robust and high-performance sulfur cathode. Unfortunately, the current approaches focus on the development of sulfur-carbon composites without a fundamental understanding of the reduction mechanism of sulfur and the role of carbon. To develop a clear understanding of the efficacy of carbon/sulfur composites, we investigated the electrochemical behavior of Li-S batteries employing different cathode structures. Our comparative study suggests that nanoscale electrical contact between sulfur and carbon is not essential for improving the electrochemical performance of Li-S batteries or for initiating electrochemical redox reactions of the sulfur cathode.</P>

Influence of Forskolin on Central Control of Rabbit Renal Function

Koh, Jeong Tae,Kim, Kyung Keun,Lim, Young Chai,Kook, Young Johng Chonnam National UniversityResearch Institute of 1993 Chonnam journal of medical sciences Vol.6 No.2

High-Performance Soft Carbons Prepared by Treatment with Various Phosphorus Acids

Jeong, Seong Hun,Koh, Jeong Yoon,Kim, Tae Jeong,Jung, Yongju Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.8

Phosphorus-doped soft carbons were successfully prepared by carbonizing petroleum cokes treated with phosphorus acids, such as $H_3PO_2$, $H_3PO_3$, and $H_3PO_4$. The effect of the type of phosphorus acids used on the composition, structure, and electrochemical performance of the soft carbons was extensively investigated. The soft carbons modified with $H_3PO_3$ and $H_3PO_4$ exhibited dramatically improved reversible capacities and outstanding rate capabilities.