• Archives of Plastic Surgery
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• 제33권6호
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• pp.742-747
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• 2006

Purpose: The purpose of this study was to evaluate the role of mast cell and histamine as typical product of mast cell in ischemia-reperfusion injury of muscle flap using H2 receptor blocker and mast cell stabilizer. Methods: Thirty-five Sprague-Dawley rats weighing 250-300 gm were divided into four groups; Group I: Control group without ischemia, Group II: Normal saline injection group with ischemia, Group III: Cimetidine injection group with ischemia, Group IV: Sodium cromoglycate injection group with ischemia. Well established single pedicled transverse rectus abdominis musculocutaneous(TRAM) flap was designed in all rats and were rendered ischemia by clamping the artery for 150 minutes. All injections were applied intramuscular around gluteal area 30 minutes before reperfusion. The flap survival was evaluated at 7 days after operation. Neutrophil counts and mast cell counts were evaluated 24 hours after reperfusion. Results: The difference of skin flap survival between control group and cimetidine injection group was not significant. In the normal saline injection group flap survival was markedly decreased compared to that of control group. The muscle flap survival was similar to the results of skin flap survival. The neutrophil counts were significantly decreased in control group and sodium cromoglycate injection group than normal saline injection group. The mast cell counts were significantly decreased in cimetidine injection group and control group than both normal saline injection and sodium cromoglycate injection groups. The protective effect of sodium cromoglycate was not seen in the skin flap, but the muscle flaps showed protective effects of sodium cromoglycate compared to normal saline injection group. Conclusions: It is suggests that commonly used antihistamine(H2 receptor blocker) has protective effect against ischemia-reperfusion injury to skin and muscle flaps by reducing neutrophil and mast cell. The mast cell stabilizer was not effective for skin flap but, possibly, for muscle flap.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권6호
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• pp.413-420
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• 2002

Mercury is one of the most frequently used heavy metal in dental clinic. Mercury poisoning rises up when someone is exposed to mercury chronically. In 1818, Amalgam was used for dental restorative procedure, and after then study about mercury toxicity has begun. Clinical signs of mercury toxicity in oral & maxillofacial area were increases of salivation, metallic taste, swelling and pain of tongue, redness and ulceration of oral mucosa, and increased mobility and loss of teeth. After we injected mercury($HgCl_{2}$) into intraperitoneum of rat, studied about histopathological changes of submandibular gland cell. Experimental group was divided into two groups by amount of mercury. (Group 1 was 0.5mg/Kg of mercury injection, group 2 was 1.0mg/Kg of mercury injection.) 1. After 3days of intraperitoneal injection, black granules were observed at macrophage cell in both group. In group 2, author found hyperchromatism of nucleus, and vacuolization of cellular matrix and nucleus of acinar cell. 2. After 1week of intraperitoneal injection, author found severe vacuolization of nucleus and cellular matrix, and irregular granules around nuclear membrane at mucous cell and serous cell in both group. Vacuolization of nucleus and cellular matrix was seen at duct cell in group 2. 3. After 2weeks of intraperitoneal injection, author could found severe vacuolization of cellular matrix, and sometimes nucleus was positioned in central area of cellular matrix at mucous and serous cell in both group. Vacuolization of nucleus and cellular matrix was found at vascular endothelial cell in group 2. 4. After 4weeks of intraperitoneal injection, destruction and distortion of gland cells were distinct. Vacuolization and destruction of nucleus and cellular matrix was found at duct cell in group 2. After intraperitoneal injection of mercury, we found equanimity of mercury and destruction of cellular matrix at serous cell, mucous cell, and duct cell of submandibular gland. So, we thought that metallic taste of mercury poisoning patient would be due to excretion of saliva containing mercury.

• 한국지능시스템학회논문지
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• 제14권4호
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• pp.411-417
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• 2004

최근 바이오 관련산업의 발전과 함께 바이오 장비 및 장치들에 대한 연구 및 개발이 활발하게 진행되고 있다. 특히 바이오 세포 조작관련 연구들이 많이 진행되어 오고 있다. 일반적으로 바이오 세포들에 대해 기계적인 엔드 이펙터들이 조작을 위해 접촉될 때 과도한 힘이 발생될 경우가 발생하며 이런 힘들에 의해 세포막이나 조직들이 피해를 입을 수 있다. 본 논문에서는 상기 문제들을 극복하기 위해 바이오 세포 조작을 위한 새로운 시스템을 제안하였다. 제안된 시스템은 내장된 힘 센서를 이용하여 바이오 세포와 엔드 이펙터간의 발생 힘을 측정할 수 있다. 또한, 비전기술을 이용하여 엔드 이펙터의 피펫 팀을 바이오 세포막까지 정확하게 가이드 할 수 있다. 결과적으로 제안된 시스템은 바이오 세포에 피해를 주지 않고 안전하게 조작이 가능하다. 제안된 기술을 이용하여 실제 시작품을 제작하여 다양한 실험을 수행한 결과 향후 DNA 조작과 같은 바이오 세포 조작용 정밀 인젝션 시스템으로의 사용 가능성을 보여 주었다.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.657-667
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• 2016

Critical limb ischemia (CLI) is one of the most severe forms of peripheral artery diseases, but current treatment strategies do not guarantee complete recovery of vascular blood flow or reduce the risk of mortality. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported to have a paracrine influence on angiogenesis in several ischemic diseases. However, little evidence is available regarding optimal cell doses and injection frequencies. Thus, the authors undertook this study to investigate the effects of cell dose and injection frequency on cell survival and paracrine effects. MSCs were injected at $10^6$ or $10^5$ per injection (high and low doses) either once (single injection) or once in two consecutive weeks (double injection) into ischemic legs. Mice were sacrificed 4 weeks after first injection. Angiogenic effects were confirmed in vitro and in vivo, and M2 macrophage infiltration into ischemic tissues and rates of limb salvage were documented. MSCs were found to induce angiogenesis through a paracrine effect in vitro, and were found to survive in ischemic muscle for up to 4 weeks dependent on cell dose and injection frequency. In addition, double high dose and low dose of MSC injections increased vessel formation, and decreased fibrosis volumes and apoptotic cell numbers, whereas a single high dose did not. Our results showed MSCs protect against ischemic injury in a paracrine manner, and suggest that increasing injection frequency is more important than MSC dosage for the treatment CLI.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3224-3229
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• 2007

This study aims to analyse the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. The steam is generated by recovering heat from the exhaust gas. Two system configurations, with difference being the operating pressure of the SOFC, are examined and effects of steam injection on performances of the two systems are compared. Two representative gas turbine pressure ratios are simulated and a wide range of both the fuel cell temperature and the turbine inlet temperature is examined. Without steam injection, the pressurized system generally exhibits better system efficiency than the ambient pressure system. Steam injection increases system power capacity for all design cases. However, its effect on system efficiency varies much depending on design conditions. The pressurized system hardly takes advantage of the steam injection in terms of the system efficiency. On the other hand, steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. A higher pressure ratio provides a better chance of efficiency increase due to steam injection.

• 한국전기전자재료학회논문지
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• 제19권7호
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• pp.695-699
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• 2006

Injection time of liquid crystal (LC) by capillary action in a vertically aligned (VA) nematic LC cell takes longer than that in a homogeneously aligned (HA) LC cell because Miesowicz viscosity in the former is bigger than that in the latter. To reduce liquid crystal injection time in the VA cell, we applied vertical electric field while injecting so that the orientation of LC molecules is changed from vertical alignment to homogeneous alignment. Consequently, the injection speed is improved by 25 % when compared with the cell without an applied field.

• Asian-Australasian Journal of Animal Sciences
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• 제4권3호
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• pp.251-254
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• 1991

Immobilized (killed) mouse spermatozoa or sperm head were microinjected into mouse oocytes matured in vivo and cultured for 72h in vitro. When non-capacitated spermatozoon was injected, oocytes that developed to $${\geq_-}$$ 2-cell and $${\geq_-}$$ 4-cell was 27.8 (15/54) and 3.7% (2/54), respectively. When non-capacitated sperm head was injected. development to $${\geq_-}$$ 2-cell and $${\geq_-}$$ 4-cell was 21.3 (16/75) and 8.0% (6/75), respectively. When capacitated spermatozoon was injected, development to $${\geq_-}$$ 2-cell and $${\geq_-}$$ 4-cell was 21.4 (15/70) and 4.3% (3/70), respectively. When capacitated sperm head was injected, development to $${\geq_-}$$ 2-cell and $${\geq_-}$$ 4-cell was 29.9 (35/117) and 10.3% (12/117), respectively. In contrast, none developed beyond 4-cell in the sham-operated group. The results of this study demonstrated that mouse oocytes matured in vivo can undergo normal appearing cleavage to 4-cell stage by dead-sperm injection. Sperm treatment prior to injection did not affect the ability of mouse oocytes to cleave in vitro.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.491-495
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• 2004

The industries use polymer materials for many purposes for they have many merits. The costs of these materials take up too great a proportion of the overall cost of products that use these materials as their major material. It is advantage for polymer industries to reduce these costs. The microcellular foaming process was developed in the early 1980s to solve this problem and proved to be quite successful. Microcellular foaming process uses inert gases such as $CO_2$, $N_2$. As these gases solve into polymer matrices, many properties are changed. The microcellular foaming process makes the glass transition temperature of polymers to low, and diminish the residual stress of polymer matrices. Besides, the microcellular foaming process has several merits, impact strength elevation, thermal insulation, noise insulation, and raw material saving etc. This characteristic of microcellular foaming process has influenced by cell morphology. The cell morphology means cell size and cell density. The cell morphology has influenced by many factors. The examples of factor are pressure drop rate, foaming temperature, foaming time, saturation pressure, saturation time etc. Among their factors, pressure drop rate is the most important factor for cell morphology in microcellular foaming injection molding process. This paper describes about the cell morphology change in accordance with the pressure drop rate of microcellular foaming injection molding process.

• 대한한방내과학회지
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• 제1권1호
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• pp.98-106
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• 1976

In order to study the effect of croton oil on the mucous cell in the mice intestin the experimental animals were injected with 0.1gm body weight of croton oil through intraperitoneally. They were sacrificed by ether anesthesia and obtained from distal small intestine and duodenum and colon, and fixed in 10% meutral formal. After embedded in paraffin, sectioned in 5 micro thickness, and stained with P.A.S (Periodic Acid Schiffis) reaction. The average number of the mucous cell was counted in each specimen over 20 fields under 450 magnification. The following results were obtained; 1) An average number of mucous cell began rapidly increase from 15 min and reached high average number after injection of croton oil of mucous cell from 30-60 min after injection. 2) An average number of mucous cell rapidly increase after injection of croton oil and were not reduced normal level by time lapsed 48 hrs. 3) The mucous cell showed with tape of time after injection of croton oil. A type and B type decrease and showed recovery C type decrease and recovery. 4) According to the above findings, it is presumed that croton oil accelerate secretion of mucin of the mucouse cell and production of mucin in growing mucous cell.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.524-526
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• 2007

Polymer dispersed liquid crystal (PDLC) films consist of micro-droplets of liquid crystals dispersed in a polymer matrix. To make wide area PDLC filled devices, it is necessary to develop reliable method of vacuum injection of PDLC solution instead of the capillary injection. However, well-known 2-ethylhexylacrylate (EHA), main element of a prepolymer, exhibits the volatility problems, when the PDLC solution is placed under the low pressure. In this study, we developed the vacuum injection process to fill a wide area cell. Experimental results indicate that the $V_{90}$(turn-on voltage) of the PDLC cell made by a vacuum injection method are lower than that of the PDLC cell made by a capillary injection method.