• Journal of Periodontal and Implant Science
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• 제38권sup2호
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• pp.325-334
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• 2008

Purpose: The carrier used as delivery agent for bone morphogenetic proteins(BMPs) should also act as a scaffold for new bone formation. Moreover, bone formation should be predictable in terms of the volume and shape. This study examined the osteogenic effect of macroporous biphasic calcium phosphate (MBCP) block combined with ePTFE membrane as a carrier for recombinant human bone morphogenetic proteins (rhBMP-2). In addition, the additive effect of ePTFE membrane on bone formation was evaluated. Materials and Methods: Eight-millimeter critical sized calvarial defects were created surgically in 28 male Sprague-Dawley rats. The animals were divided into 2 groups containing 14 animals each. The defects were treated with either rhBMP-2/MBCP block (rhBMP-2/MBCP group) or rhBMP-2/MBCP block/ePTFE membrane (rhBMP-2/MBCP/ePTFE group). A disc-shaped MBCP block (3 mm height and 8 mm diameter) was used as the carrier for the rhBMP-2 and ePTFE membrane was used to cover the rhBMP-2/MBCP block. The histologic and histometric parameters were used to evaluate the defects after 2- or 8-week healing period (7 animals/group/healing interval). Results: The level of bone formation in the defects of both groups was significantly higher at 8 weeks than that at 2 weeks (P < 0.05). The ePTFE membrane has no additional effect compared with the rhBMP-2/MBCP block only. However, at 8 weeks, rhBMP-2/MBCP/ePTFE group showed more even bone formation on the top of the MBCP block than the rhBMP-2/MBCP group. Conclusion: These results suggest that the ePTFE membrane has no additive effect on bone formation when a MBCP block is used as a carrier for rhBMP-2.

• Journal of Korean Neurosurgical Society
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• 제29권4호
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• pp.461-470
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• 2000

Objective : Many investigators have demonstrated the protective effects of hypothermia following traumatic brain injury(TBI) in both animals and humans. It has long been recognized that mild to moderate hypothermia improves neurologic outcomes as well as reduces histologic and biochemical sequelae after TBI. In this study, two immunohistochemical staining using terminal deoxynucleotidyl-transferase-mediated biotin dUTP nick end labeling(TUNEL), staining of apoptosis, and ${\beta}$-amyloid precursor protein(${\beta}$-APP), a marker of axonal injury, were done and the authors evaluated the protective effects of hypothermia on axonal and neuronal injury after TBI in rats. Material and Method : The animals were prepared for the delivery of impact-acceleration brain injury as described by Marmarou and colleagues. TBI is achieved by allowing of a weight drop of 450gm, 1 m height to fall onto a metallic disc fixed on the intact skull of the rats. Fourty Sprague-Dawley rats weighing 400 to 450g were subjected to experimental TBI induced by an impact-acceleration device. Twenty rats were subjected to hypothermia after injury, with their rectal temperatures maintained at $32^{\circ}C$ for 1 hour. After this 1-hour period of hypothermia, rewarming to normothermic levels was accomplished over 30-minute period. Following 12 hours, 24 hours, 1 week and 2 weeks later the animals were killed and semiserial sagittal sections of the brain were reacted for visualization of the apoptosis and ${\beta}$-APP. Results : The density of ${\beta}$-APP marked damaged axons within the corticospinal tract at the pontomedullary junction and apoptotic cells at the contused cerebral cortex were calculated for each animal. In comparison with the untreated controls, a significant reduction in ${\beta}$-APP marked damaged axonal density and apoptotic cells were found in all hypothermic animals(p<0.05). Conclusion : This study shows that the posttraumatic hypothermia result in substantial protection in TBI, at least in terms of the injured axons and neurons.

• 한국산림과학회지
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• 제78권2호
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• pp.119-131
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• 1989

본(本) 실험(實驗)은 압축이상재(壓縮異常材)가 잘 형성(形成)된 소나무(Pinus densiflora S. et Z.)의 굽어진 수간(樹幹)과 곧은 지재(枝材) 및 지면(地面)에 노출된 측근(測根)에서 압축이상재율(壓縮異常材率)과 편심율(偏心率)변이에 따른 압축이상재(壓縮異常材)와 대응재(對應材) 및 측면재(側面材)의 조직학적(組織學的) 특성(特性)과 방사조직(放射組織)의 수량적(數量的) 특성(特性)을 조사(調査) 검토(檢討)하고자 실시(實施)하였다. 본(本) 시험(試驗)에서 수간(樹幹)은 지상(地上)에서 수고방향(樹高方向)으로 상승함에 따라, 지재(枝材)는 수간(樹幹)에서 가지방향으로 멀어짐에 따라, 압축이상재율(壓縮異常材率)과 편심율(偏心率)이 줄어드는 경향을 나타내었으므로 20cm간격으로 각각 4개씩의 원판(圓板)을 채취(採取)하여 시편(試片)으로 사용(使用)하였다. 또한 근재(根材)는 압축이상재(壓縮異狀材)가 가장 양호(良好)하게 형성(形成)된 부위(部位)에서 한 개의 원판(圓板)을 채취(採取)하여 사용(使用)하였다. 압축이상재(壓縮異常材)의 조직학적(組織學的) 특성(特性)은 횡단면상(橫斷面上) 가도관(假導管)의 둥근형태(形態), 춘재(春材)로 부터 추재(秋材)로의 매우 점진적(漸進的)인 가도관이행(假導管移行), 가도관선단부의 뒤얽힘 및 나선강(螺旋腔)과 세포간극의 존재 등 측면재(側面材) 및 대응재(對應材)와 다른 특성(特性)을 나타냈으며, 압축이상재율(壓縮異常材率)과 편심율(偏心率)이 작아짐에 따라 압축이상재(壓縮異常材)와 대응재(對應材) 및 측면재간조직학적(側面材間組織學的) 특성(特性)의 차이(差異)가 다소 줄어드는 경향을 보였지만 그 특성(特性)은 유지(維持)됨을 알 수 있었다. 또한 압축이상재(壓縮異常材)의 단위면적 당 수직 수지구수는 대응재(對應材)다 적었으나 단위연륜당 수직수지구의 수는 압축이상재(壓縮異常材)가 대응재(對應材)보다 많았으며 단위면적당 방추형방사조직(紡錘形放射組織)(평균수지구(水平樹脂溝)의 수(數와) 단열방사조직(單列放射組織)의 수(數)는 압축이상재(壓縮異常材)와 대응재(對應材) 및 측면재간(側面材間)에 차이(差異)가 없였다. 그렇지만 압축이상재(壓縮異常材)의 방추형방사조직(紡錘形放射組織)과 단열방사조직(單列放射組織)의 폭(幅)은 대응재(對應材) 및 측면재(側面材)보다 넓으나 이들의 세포고(細胞高)는 낮은 경향(傾向)을 나타내어 이들 방사조직(放射組織)의 폭(幅)과 세포고(細胞高)는 압축이상재(壓縮異常材)의 고유한 특성(特性)이라 생각되었다.

• 대한소아치과학회지
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• 제33권1호
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• pp.25-34
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• 2006

불소는 구강내에서 치아 우식의 예방 및 초기 우식의 재광화를 유도하기 위한 목적으로 널리 사용되고 있으며, 불소가 유리되는 수복물을 이용하게 되면, 수복물 주위의 이차 우식 및 구강내의 우식 감수성을 감소시킬 수 있다. 현재 소아치과 영역에서 주로 사용되고 있는 불소유리 수복재로는, 전통적인 글라스 아이오노머와 레진 강화형 글라스 아이오노머, 컴포머 등이 있는데, 본 연구에서는 현재 소아치과 영역에서 많이 사용되고 있는 불소를 유리하는 수복재의 불소 유리량 및 불소 적용방법에 따른 불소유리량의 변화를 비교하고 확인하고자 한다. 복합레진으로 $Z-250^{TM}$ (Group I)과 컴포머로 $Dyract^{(R)}$ AP(Group II) 레진 강화형 글라스 아이오노머로 Fuji II $LC^{(R)}$ (Group III), 자가중합형 글라스 아이오노머로 Fuji IX GP $Fast^{(R)}$(Group IV)를 실험대상으로 선정하였다. 각 재료별로 동일한 크기의 디스크를 제작하여, 31일 동안 매일 새로운 용액으로 교환하면서 불소 유리량을 측정하였다(실험 I). 이후 수복재료별로 불소 적용 방법에 따라 4군으로 나누는데, A군은 대조군(No treatment)으로, B군은 불소가 함유된 치약(500ppm, Stages, $Oral-B^{(R)}$, Holland)을 3분간 3회 적용하고, C군은 1.23% APF Foam(1000ppm, Sultan Topex, #31150, Canada)을 1회 적용하며, D군은 B군과 동일한 치약을 3회 적용하고, 1.23% APF Foam을 1회 적용하였다. 불소 적용 후 7일 동안 불소 유리량을 측정하였다(실험 II). 실험 I에서, 실험 개시일부터 7일까지 불소 유리량이 급속히 감소하고, 이후 일정한 불소 유리량을 보였다. III군 (Fuji II-$LC^{(R)}$)과 IV군 (Fuji IX GP $Fast^{(R)}$)이 다른 군에 비해 높은 불소 유리량을 보였으며, III군과 IV군 사이에서는 유의한 차이를 보이지 않았다. 실험 II에서, 불소 적용 후 II, III, IV군에서 불소 유리 량이 증가한 양상을 보이는데, II군에서는 불소 적용 후 2일, III군에서는 5일, IV군에서는 4일부터 초기 불소 유리량 수준으로 돌아갔다.

• 방사선산업학회지
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• 제9권2호
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• pp.85-90
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• 2015

Purpose: Time of operation has been reduced and accuracy of operation has been improved since C-arm, which offer real-time image of patient, was introduced in operation room. However, because of the contamination of patient, C-arm could not be used more appropriately. Therefore, this study is to know factors of controlling exposure dose, image quality and the exposed dose of health professional in operation room. Materials and methods: Height of Wilson frame (bed for operation) was fixed at 130 cm. Then, Model 76-2 Phantom, which was set by assembling manual of Fluke Company, was set on the bed. Head/Spine Fluoroscopy AEC mode was set for exposure condition. According to detector size of C-arm, the absorbed dose per min was measured in the 7 steps OFD (cm) from 10 cm to 40 cm (10, 15, 20, 25, 30, 35, 40 cm). In each step of OFD, the absorbed dose per min of same diameter of collimation was measured. Moreover, using Nero MAX Model 8000, exposure dose per min was measured according to 3 step of distance from detector (20 cm, 60 cm, 100 cm). Finally, resolution was measured by CDRH Disc Phantom and magnification of each OFD was measured by aluminum stick bar. Result: According to detector size of C-arm, difference of absorbed dose shows that the dose of 20 cm OFD is 1.750 times higher than the dose of 40 cm OFD. It means that the C-arm, which has smaller size of detector, shows the bigger difference of absorbed dose per min (p<0.05). In the difference of absorbed dose in the same step of OFD (from 20 cm to 40 cm), the absorbed dose of 9 inch detect or C-arm was 1.370 times higher than 12 inch' s (p<0.05). When OFD was set to 20 cm OFD, the absorbed dose of non-collimation case was approximately 0.816 times lower than the absorbed dose of collimation cases (p<0.05). When the distance was 20 cm from detector, exposed does includes first-ray and scatter-ray. When the distance was 60 cm and 100 cm from detector, exposed does includes just scatter-ray. So, there was the 2.200 times difference of absorbed does. Finally, when OFD was increased, spatial resolution was 4 to 5 step was increased. However, low contrast resolution was not relative. Moreover, there was 1.363 times difference of magnification (p<0.05). Conclusion: When C-Arm is used, avoiding contamination of patient is more important factor than reducing exposed dose of health professional in operation room. Just controlling exposure time is just way to reduce the exposed does of workers. However, in the case, non-probability influence could be occurred. Therefore, this study proved that the exposed dose will be reduced if the factors such as using small detector size of C-arm, setting OFD from 20 cm to 25 cm and non-collimating. Moreover, dose management of C-arm in the non-interesting area will be considered additionally.