• Journal of Korean Neurosurgical Society
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• 제47권4호
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• pp.287-290
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• 2010

Objective : The authors evaluated the accuracies and ease of use of several commonly used microanastomosis training models (synthetic tube, chicken wing, and living rat model). Methods : A survey was conducted among neurosurgeons and neurosurgery residents at a workshop held in 2009 at the authors' institute. Questions addressed model accuracy (similarity to real vessels and actual procedures) and practicality (availability of materials and ease of application in daily practice). Answers to each question were rated using a 5-point scale. Participants were also asked what types of training methods they would chose to improve their skills and to introduce the topic to other neurosurgeons or neurosurgery residents. Results : Of the 24 participants, 20 (83.3%) responded to the survey. The living rat model was favored for model accuracy (p<0.001; synthetic tube $-0.95{\pm}0.686$, chicken wing, $0.15{\pm}0.587$, and rat, $1.75{\pm}0.444$) and the chicken wing model for practicality (p<0.001; synthetic tube $-1.55{\pm}0.605$, chicken wing, $1.80{\pm}0.523$, and rat,$1.30{\pm}0.923$). All (100%) chose the living rat model for improving their skills, and for introducing the subject to other neurosurgeons or neurosurgery residents, the chicken wing and living rat models were selected by 18 (90%) and 20 (100%), respectively. Conclusion : Of 3 methods examined, the chicken wing model was found to be the most practical, but the living rat model was found to represent reality the best. We recommend the chicken wing model to train surgeons who have mastered basic techniques, and the living rat model for experienced surgeons to maintain skill levels.

• 대한간호학회지
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• 제40권4호
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• pp.580-588
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• 2010

Purpose: The purpose of this study was to examine effects of decreased locomotor activity on mass, Type I and II fiber cross-sectional areas of ipsilateral and contralateral hindlimb muscles 21 days after establishing the Parkinson's disease rat model. Methods: The rat model was established by direct injection of 6-hydroxydopamine (6-OHDA, 50 ${mu}g$) into the left substantia nigra after stereotaxic surgery. Adult male Sprague-Dawley rats were assigned to one of two groups; the Parkinson's disease group (PD; n=17) and a sham group (S; n=8). Locomotor activity was assessed before and 21 days after the experiment. At 22 days after establishing the rat model, all rats were anesthetized and soleus and plantaris muscles were dissected from both ipsilateral and contralateral sides. The brain was dissected to identify dopaminergic neuronal death of substantia nigra in the PD group. Results: The PD group at 21 days after establishing the Parkinson's disease rat model showed significant decrease in locomotor activity compared with the S group. Weights and Type I and II fiber cross-sectional areas of the contralateral soleus muscle of the PD group were significantly lower than those of the S group. Conclusion: Contralateral soleus muscle atrophy occurs 21 days after establishing the Parkinson's disease rat model.

• 한국수자원학회논문집
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• 제43권7호
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• pp.667-679
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• 2010

분포형 수문모형은 컴퓨터 하드웨어의 급속한 발전과 GIS를 이용한 수문지리공간정보에의 접근성 및 활용성 증가에 따라 근래에 많은 발전을 이루게 되었다. 하지만 물리기반의 분포형 수문모형은 입력자료 구축 및 모형구동에 많은 시간과 노력이 필요하며 수문자료가 불충분한 미계측 유역에서는 모형의 구축이 어렵다는 한계점을 지니고 있다. 이에 본 논문에서는 개념적 격자 물수지 기법을 이용한 개념적 분포형 수문모형 S-RAT을 개발하였다. S-RAT 모형은 집중형 수문모형의 자료구축의 간편성과 분포형 수문모형의 공간적 유출해석 능력을 동시에 만족할 수 있으며 격자기반 레이더강우자료를 활용할 수 있다. 또한 전처리과정 및 유역의 지형자료 추출 기능을 탑재함으로 상용 GIS 분석 도구들에 대한 의존성이 없는 장점을가진다. 본 논문에서는 도시유역인 중랑천 유역과 산지유역인 내린천 유역 적용을 통해 S-RAT 모형의 유출모의능력 및 매개변수의 시공간적 전이성을 확인하였으며 지상강우와 레이더강우의 입력 자료로써의 활용성을 확인하였다.

• 한방안이비인후피부과학회지
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• 제28권4호
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• pp.41-50
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• 2015

Objectives : 선태는 아토피 피부염에서 소양증 완화를 위해 사용되고 있다. 본 연구에서는 면역계 및 신경계 손상을 일으킨 rat model에서 선태 추출물이 소양증 완화에 효과가 있는지 알아보고자 한다.Methods : 출생 48시간 이내의 rat을 대상으로, capsaicin(50 mg/kg)을 피하 투여하였다. 임의로 선정된 12마리의 실험군에 3주 동안 선태 추출물(0.5g/kg)을 매일 경구 투여하였다. 이후 scratching behavior 와 dermatitis score를 측정하였다.Results : 선태 투여군과 대조군에서 scratching number 와 dermatitis score의 차이가 없었다.Conclusions : 위의 결과로부터 capsaicin으로 유발한 아토피 피부염 rat model에서 선태의 소양증 완화 효과가 없다는 것을 알 수 있었다. 아토피 피부염의 효과적인 치료를 위해 면역계 뿐만 아니라 신경계 손상 회복시키는 약물을 찾기 위한 더 많은 연구가 필요할 것으로 생각된다.

• Journal of electromagnetic engineering and science
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• 제6권1호
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• pp.47-52
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• 2006

The objective of this study is to evaluate the effects of size and permittivity on the specific absorption rate(SAR) values of rat brains during microwave exposure at mobile phone frequency bands. A finite difference time domain (FDTD) technique with perfect matching layer(PML) absorbing boundaries is used for this evaluation process. A color coded digital image of the Sprague Dawley(SD) rat based on magnetic resonance imaging(MRI) is used in FDTD calculation with appropriate permittivity values corresponding to different tissues for 3, 4, 7, and 10 week old rats. This study is comprised of three major parts. First, the rat model structure is scaled uniformly, i.e., the rat size is increased without change in permittivity. The simulated SAR values are compared with other experimental and numerical results. Second, the effect of permittivity on SAR values is examined by simulating the microwave exposure on rat brains with various permittivity values for a fixed rat size. Finally, the SAR distributions in depth, and the brain-averaged SAR and brain 1 voxel peak SAR values are computed during the microwave exposure on a rat model structure when both size and permittivity have varied corresponding to different ages ranging from 3 to 10 weeks. At 900 MHz, the simulation results show that the brain-averaged SAR values decreased by about 54 % for size variation from the 3 week to the 10 week-old rat model, while the SAR values decreased only by about 16 % for permittivity variation. It is found that the brain averaged SAR values decreased by about 63 % when the variations in size and permittivity are taken together. At 1,800 MHz, the brain-averaged SAR value is decreased by 200 % for size variation, 9.7 % for permittivity variation, and 207 % for both size and permittivity variations.

• Asian Spine Journal
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• 제12권6호
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• pp.998-1009
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• 2018

Study Design: Olfactory ensheathing cells (OECs) from rat olfactory mucosa were cultured, characterized, and transplanted into a rat model of spinal cord injury (SCI). Purpose: To evaluate different doses of OECs in a rat model of SCI. Overview of Literature: SCI causes permanent functional deficit because the central nervous system lacks the ability to perform spontaneous repair. Cell therapy strategies are being explored globally. The clinical use of human embryonic stem cell is hampered by ethical controversies. Alternatively, OECs are a promising cell source for neurotransplantation. This study aimed to evaluate the efficacy of different doses of allogenic OEC transplantation in a rat model of SCI. Methods: OECs were cultured from the olfactory mucosa of Albino Wistar rats; these cells were characterized using immunohistochemistry and flow cytometry. Rats were divided into five groups (n=6 rats each). In each group, different dosage ($2{\times}10^5$, $5{\times}10^5$, $10{\times}10^5$, and >$10{\times}10^5$) of cultured cells were transplanted into experimentally injured spinal cords of rat models. However, in the SCI group, only DMEM (Dulbecco's modified Eagle's medium) was injected. Rats were followed up upto 8 weeks post-transplantation. The outcome of transplantation was assessed using the Basso, Beattie, Bresnahan (BBB) scale; motor-evoked potential studies; and histological examination. Results: Cultured cells expressed 41% of p75NTR, a marker for OEC, and 35% of anti-fibronectin, a marker for olfactory nerve fibroblast. These cells also expressed $S100{\beta}$ and glial fibrillary acid protein of approximately 75% and 83%, respectively. All the transplanted groups showed promising BBB scores for hind-limb motor recovery compared with the SCI group (p<0.05). A motor-evoked potential study showed increased amplitude in all the treated groups compared with the SCI. Green fluorescent protein-labeled cells survived in the injured cord, suggesting their role in the transplantation-mediated repair. Transplantation of $5{\times}10^5$ cells showed the best motor outcomes among all the doses. Conclusions: OECs demonstrated a therapeutic effect in rat models with the potential for future clinical applications.

• Journal of Chest Surgery
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• 제21권2호
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• pp.231-239
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• 1988

Currently numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operation. During cardiac ischemia after crystalloid cardioplegia[4C GIK solution], topical cold saline[Group I, a=9], topical ice slush[Group II, n=9] and topical ice chip[Group III, a=10] have been compared for myocardial surface cooling in the isolated rat heart model of cardiopulmonary bypass. During postischemic period, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure and heart rate], biochemical enzymatic activities and cellular injuries with electron microscope were evaluated in this isolated rat heart perfusion model. Postischemic aortic flow, cardiac output and peak aortic pressure in Group I and Group II recovered better than Group III.[p< 0.05] Postischemic creatine kinase and lactate dehydrogenase leakages in Group II and Group III increased more than Group l and postischemic mitochondrial swelling in Group III was more severe than Group I, and Group II.[p< 0.05] These results suggest that topical cold saline was the better method than topical ice slush or topical ice chip as a myocardial preservation modality in the isolated rat heart model of cardiopulmonary bypass.

• Journal of Chest Surgery
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• 제51권6호
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• pp.423-426
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• 2018

This study determined the feasibility of the cuff technique for small-caliber vascular grafts in a rat model. A graft was implanted with the cuff technique or suture technique in a 1-cm segment of the abdominal aorta in 12 rats. The mean aortic clamp time was 29 minutes with the cuff technique and 44 minutes with the suture technique; the cuff technique was significantly shorter. Abdominal angiography at 1 week after implantation showed no significant stenosis in 9 rats, focal stenosis of the mid-portion of the graft in 1 rat with each technique, and total occlusion of the graft in 1 rat with the suture technique. We have successfully used the cuff technique for anastomosis for small-caliber vascular grafts in an animal model.

• 한국방사선학회논문지
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• 제10권6호
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• pp.375-379
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• 2016

방사선장해 극복을 위한 조직공학실험에서는 다양한 실험방법이 존재한다. 그중에서도 방사선 장해모델을 구현함에 있어서 쥐는 가장 많이 사용되는 실험동물이다. 이번 실험에서는 쥐 피부를 벗긴 후 일정한 두께로 만든 후에 피부 두께에 따른 방사선량을 측정하였다. 또한 쥐의 피부 두께에 따른 방사선 흡수선량을 유추해 날수 있는 수식을 도식화 하였다. 결론적으로 이러한 수식을 적용한다면 방사선장해극복을 위한 조직공학 연구에서 사용하는 다양한 지지체삽입시에 지지체가 받을 수 있는 방사선량의 정도를 유추해 낼 수 있으며 이것을 통하여 쥐 피부두께 피하에 관한 체내 (in-vitro)실험모델 구현 시 방사선량의 정보를 제공하고자 한다. 따라서 이번 연구의 결과를 기반으로 사용한다면 방사선이 노출된 쥐의 피하조직 체내 (in-vitro) 조직공학 실험에서 효과적으로 사용 될 수 있을 것이다.

• Archives of Plastic Surgery
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• 제41권3호
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• pp.201-208
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• 2014

Microsurgery is a precise surgical skill that requires an extensive training period and the supervision of expert instructors. The classical training schemes in microsurgery have started with multiday experimental courses on the rat model. These courses have offered a low threat supervised high fidelity laboratory setting in which students can steadily and rapidly progress. This simulated environment allows students to make and recognise mistakes in microsurgery techniques and thus shifts any related risks of the early training period from the operating room to the lab. To achieve a high level of skill acquisition before beginning clinical practice, students are trained on a comprehensive set of exercises the rat model can uniquely provide, with progressive complexity as competency improves. This paper presents the utility of the classical rat model in three of the earliest microsurgery training centres and the new prospects that this versatile and expansive training model offers.