• Journal of Periodontal and Implant Science
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• 제26권2호
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• pp.448-468
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• 1996

To maintain its functional integrity, bone is continuously remodelled by a process involving resorption by osteoeclasts and formation by osteoblasts, In order to respond to changes in the physical environment or to trauma with the relevant action, this process is strictly regulated by locally synthesized or systemic fators, Prostaglandin $E_2(PGE_2$) is perhaps one of the best studied factors, having been known to affect bone cell function for several decades.$PGE_2$ has both anabolic and catabolic activities. Excess of $PGE_2$ has been implicated in a number of pathological states associated with bone loss in a number of chronic inflammatory conditions such as periodontal disease and rheumatoid arthritis. $PGE_2$ and other arachidonic acid metabolites have been shown to be potent stimulators of osteoclastic bone resorption in organ culture. The anabolic effects of $PGE_2$ were first noticed when an increase in periosteal woven bone formation was seen after the infusion of $PGE_2$ into infants in order to prevent closure of the ductus arteriosus. The cellular basis for the catabolic actions of $PGE_2$ has been well characterized. $PGE_2$increases osteoclast recruitment in bone marrow cell cultures. Also $PGE_2$ has a direct action on osteoclast serving to inhibit activity and can also indirectly activate osteoclast via other cells in the vicinity, presumably osteoblast. The cellular mechanisms for the anabolic actions of $PGE_2$ are not nearly so well understood. The purpose of this paper was to study the effects of $PGE_2$ and dibutyl(DB)cAMP on osteoblastic clone MC3T3El cells and on the generation of osteoclasts from their precursor cells. The effect of $PGE_2$ and DBcAMP on the induction of alkaline phoaphatase(AlP) was investigated in osteoblastic clone MC3T3El cells cultured in medium containing 0.4% fetal bovine serum. $PGE_2$ and DBcAMP stimulated ALP activity and MTT assay in the cells in a dose-dependent manner at concentrations of lO-SOOng/ml. Cycloheximide, protein synthesis inhibitor, inhibited the stimulative effect of $PGE_2$ and DBcAMP on ALP activity in the cells. $PGE_2$also increased the intracellular cAMP content in a dose-dependent fashion with a maximal effect at 500ng/ml. The effect of $PGE_2$ on the generation of osteoclasts was investigated in a coculture system of mouse bone marrow cells with primary osteoblastic cells cultured in media containing 10% fetal bovine serum.After cultures, staining for tartrate-resistant acid phosphatase(TRAP)-marker enzyme of osteoclast was performed. The TRAP(+) multinucleated cells(MNCs), which have 3 or more nuclei, were counted. More TRAP(+) MNCs were formed in coculture system than in control group. $PGE_2(10^{-5}10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in culture. $PGE_2(10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in coculture of osteoblastic clone MC3T3E1 cells This results suggest that $PGE_2$ stimulates the differentiation of osteoblasts and generation of osteoclast, and are involved in bone formation, as well as in bone resorption.

• 한국가금학회지
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• 제30권2호
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• pp.119-128
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• 2003

The two experiments in this study compared litter nitrogen (N) contents after broiler chicks were raised for 42 days. Experiment I compared litter treated with aluminum sulfate (alum) [Al$_2$(SO$_4$)$_3$ㆍ14$H_2O$] (T$_1$) with nontreated litter (T$_2$) when the broiler chicks were fed the same levels of dietary protein (23% for 0∼3 weeks, 21% for 4∼6 weeks) Experiment 2 compared the alum treated litters of broiler chicks fed high protein diets (T$_3$) having 20.4% protein for 0∼3 weeks and 19.3% for 4∼6 weeks, with lower protein diets (T$_4$) having protein levels of 18.0% for 0∼3 weeks and 17.0% for 4 6 weeks. Each treatment had four replicate cages. As shown in Table 1, T$_1$ had a significantly (P<0.0l) lower pH and significantly (P<0.05) higher total N (TN), NH$_4$-N and inorganic N (IN) than T$_2$. T$_1$ and T$_2$ had similar moisture, organic carbon (OC), NO$_3$-N and organic N (ON). Alum treatment increased available N (AN) significantly (P<0.05) from 13.75$\pm$0.0l mg/g to 14.90$\pm$0.01 mg/g and predicted available N (PAN) significantly (P<0.05) from 15.00$\pm$0.0l to 16.50$\pm$0.02. The C : N ratios were 18.84$\pm$0.40 (T$_1$) and 19.46$\pm$0.10 (T$_2$) while the C : ON ratios were 28.49$\pm$1.15 (T$_1$) and 28.34$\pm$0.20 (T$_2$) although C : N ratios or C : ON ratios did not show any difference between T$_1$ and T$_2$. In Table 2, T$_3$ had significantly (P<0.05) higher moisture, TN, NH$_4$-N, ON and IN than T$_4$, while the pH, OC and NO$_3$-N were similar in both groups. The AN of T$_3$ increased significantly (P<0.05) from 10.99$\pm$0.0l mg/g to 12.98$\pm$0.03 mg/g, while the PAN increased significantly (P<0.05) from 12.39$\pm$0.10 mg/g (T$_4$) to 14.68$\pm$ 0.30 mg/g (T$_3$). The C : N ratios increased significantly (P<0.0l) from 20.07$\pm$0.20 (T$_3$) to 24.40$\pm$0.10 (T$_3$). The C : ON ratios also increased significantly (P<0.0l) from 28.99$\pm$1.15 (T$_3$) to 35.51$\pm$0.20 (T$_4$). These current research results show increased AN contents and PAN contents in alum treated litter or with increased CP levels regardless of alum treatment. However, none of the litters in this study could initially increase mineralization.

• 철학연구
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• 제105권
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• pp.49-74
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• 2008

본 연구의 목적은 토미즘에 있어서 '인간적 행위'가 가지는 '자기초월의 성격'을 조명하는 데에 있다. 토미즘에 있어서 이성과 의지를 가진 인간의 본성은 궁극적인 목적에로 지향성을 가진 것이며, 따라서 '인간의 행위'가 아닌 '인간적 행위'란 이러한 본성에 적합한 행위를 말하며, 현재의 상태보다 더 낳은 상태를 지향하는 '자기초월'을 성격을 가지는 것이다. 물론 이러한 자기초월적 성격을 본질적으로 가지게 되는 인간적 행위의 근거는 인간의 형상인 이성혼(理性魂)이 '자립적인 형상'이라는 데에 있다. 토마스 아퀴나스에게 있어서 이러한 인간적 행위의 자기초월의 성격은 크게 세 가지 단계를 거친다고 볼 수 있는데, (1)자연적 진보의 질서 안에서의 초월, (2)도덕적 질서 안에서의 자기초월 그리고 (3)종교적 삶에 있어서 자기초월이 그것이다. 자연적 진보에서는 우선적으로 이성적 영혼의 특성에서 드러나는데, 아퀴나스는 인간의 이성적인 덕을 '나약함 안에서의 충만함'이라고 규정하는데, 이는 이성적인 덕이란 '외적 감각능력들의 목적지($finalit{\acute{e}}$)'로서 고려하기 때문이다. 외적 감각을 통해서 인간은 '감각적 상(especies sensibilis)'들을 수용하며, 이미지들을 보존하고, 이 이미지들은 기억 혹은 추억이라는 형태로 그의 실존의 일부가 되며, 자기의식을 의미하는 정신적인 실재가 되는 것이다. 따라서 토마스에게 있어서 이성의 덕은 단순히 사변적인 능력이 아니라, '되어짐'의 질서, 충만함의 질서 안에 있는 것이다. 바로 이 때문에 토마스는 이성(ratio)의 능력을 '생성(generatio)'에 비유하고 있으며, 지성(intellectus)을 존재(esse)에 비유하고 있는 것이다. 즉 이성은 감각을 초월하고, 지성은 이성을 초월하는 것이다. 도덕적 질서 안에서의 자기초월은 의식의 진보와 관련되어 있는데, 인간의 의식은 언제나 이중적인데, 일차적으로 외부대상에 대한 인식이요, 이차적으로 이러한 외부대상에 대한 인식의 결과라 할 수 있는 자기의식(contientia)이다. 즉 이러한 외부대상에 대한 인식은 근본적으로 자기의식 혹은 자기인식을 목적으로 하며, 자기인식에서 완성된다. 자기의식은 '자기동일성'에 대한 의식을 말하는데, 여기서 인간의 특유한 도덕적 행위가 발생한다. 즉 당위 혹은 의무라는 것은 언제나 '자기동일성'에 대한 적합성을 의미하는 것이며, 이러한 행위가 지속적일 때, 도덕적 삶이 발생하는 것이다. 도덕적 삶이 그 자체 초월적인 성격을 가지는 것은 '자기동일성'에 적합한 인간적 행위란 언제나 '보다 나은 것' 보다 '이상적인 삶'을 지향하기 때문이다. 종교적 삶에 있어서 토미즘의 특성을 보다 잘 부각하기 위해서 본 논문에서는 키엘케고올의 종교적 삶에 대한 초월성을 우선적으로 고찰하고 있는데, 그에 의하면 종교적 삶에 있어서 초월적 성격은 '절대적 차원의 초월'로서 근본적으로 합리적으로 기술되거나 표현될 수 있는 모든 문화적인 인간적인 지평을 넘어서는 '초월' 즉 '절대적 초월($d{\acute{e}}passement$ absolu)을 의미하는 것이다. 반면 아퀴나스에게 있어서 신과 인간 사이의 '친근성($affinit{\acute{e}}$)'은 수용된 덕들(virtutes infusas)이 있는 곳에는 반드시 일종의 종교적인 초월이 수반된다. '가능태'중에 있는 하나의 (수용된)덕이 '현실태'가 되는 곳에는 반드시 '자기초월'의 행위가 수반되는 것이다. 왜냐하면 이러한 수용된 덕의 국면은 신과 인간 사이의 소통을 말해주고 있기 때문이며, 이는 곧 '인간적인 것'에서 '신성한 것'에로의 초월을 암시하고 있기 때문이다. 이러한 아퀴나스의 사유는 구체적이고 개별적인 한 인간의 종교적인 삶 안에서 '자기초월'이 이루어지는 곳에는 언제나 신의 섭리가 개입하고 있다는 실재론적인 사유를 가능하게 하고 있는 것이다.

• Nuclear Medicine and Molecular Imaging
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• 제41권3호
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• pp.241-246
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• 2007

목적: 베타아밀66로이드 양전자단층촬영 영상 추적자인 $[^{11}C]OH-BTA-1(1)$는 알쯔하이머병의 진단용으로 개발되었다. 반응용매 루프 방법에 의한 $[^{11}C]1$는 $[^{11}C]MeOTf$를 통해서 한번의 반응으로 $^{11}C$을 바로 표지 할 수 있다. 또한 반응 중에 $[^{11}C]2$가 생긴다는 것이 보고된바 있다. 하지만, 실험 중에 다른 부산물이 생기는 것이 발견되어 그 물질을 추정하고, 각 반응용매에 따른 $[^{11}C]1$과 부산물의 표지효율 변화에 대한 조사를 했다. 대상 및 방법: 사이클로트론에서 $^{14}N(p,{\alpha})^{11}C$ 핵반응과 미량의 $O_2$로 부터 의하여 생산되는 $[^{11}C]CO_2$를 0.2 M $LiAlH_4/THF$ 0.2 ml로 환원한 다음 HI 1ml과 반응하여 $[^{11}C]CH_3I$를 생산했다. 질소가스를 20 ml/min로 불어 주면서 200C 에서 AgOTf-Graphpac GC column를 통과시켜 $[^{11}C]CH_3OTf$를 생산했다. 각 반응용매 (MEK, CHO, DEK, DMF) 100 1에 녹인 전구물질 1 mg를 고성능 액체 크로마토그래피 시료 루프에 미리 주입하고 $[^{11}C]CH_3OTf$를 상온에서 7분 동안 질소가스를 불어줬다. Semi-preparative HPLC로 분리하였다. 결과: 각 반응용매에서 $[^{11}C]1$에 표지효율은 MEK: $86.0{\pm}5.5%$, CHO: $59.7{\pm}2.4%$, DEK: $29.9{\pm}1.8%$, DMF: $7.6{\pm}0.5%$이었다. MEK에서 얻은 $[^{11}C]1$의 비방사능은 98 ($GBq/{\mu}mol$)이다. 각 물질의 질량 분석은 1: m/z 257.3 (M+1), 2: 257.3 (M+1), 3: 271.3 (M+1)이었다. 각 생성물질의 표지효율은 MEK에서 $86.0{\pm}5.5%:5.0{\pm}3.4%:1.5{\pm}1.3%$ $([^{11}C]1:[^{11}C]2:[^{11}C]3)$, CHO에서 $59.7{\pm}2.4%:4.7{\pm}3.2%:1.3{\pm}0.5%$, DEK에서 $29.9{\pm}1.8%:2.0{\pm}0.7%:0.3{\pm}0.1%$, DMF에서 $7.6{\pm}0.5%:0.0%:0.0%$이다. 결론: $[^{11}C]1$은 4가지 반응용매 중 MEK 반응용매에서 가장 높은 표지효율을 나타냈다. 부산물인 $[^{11}C]3$은 고성능 액체 크로마토그래피의 자외선, 방사능 검출기와 질량 분석법을 통해 물질을 추정할 수 있었다.

• 대한치과보철학회지
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• 제40권1호
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• pp.1-17
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• 2002

The purpose of this study is to examine the possibility of thermal injury to bone tissues during an implant site preparation under the same condition as a typical clinical practice of $Br{\aa}nemark$ implant system. All the burs for $Br{\aa}nemark$ implant system were studied except the round bur The experiments involved 880 drilling cases : 50 cases for each of the 5 steps of NP, 5 steps of RP, and 7 steps of WP, all including srew tap, and 30 cases of 2mm twist drill. For precision drilling, a precision handpiece restraining system was developed (Eungyong Machinery Co., Korea). The system kept the drill parallel to the drilling path and allowed horizontal adjustment of the drill with as little as $1{\mu}m$ increment. The thermocouple insertion hole. that is 0.9mm in diameter and 8mm in depth, was prepared 0.2mm away from the tapping bur the last drilling step. The temperatures due to countersink, pilot drill, and other drills were measured at the surface of the bone, at the depths of 4mm and 8mm respectively. Countersink drilling temperature was measured by attaching the tip of a thermocouple at the rim of the countersink. To assure temperature measurement at the desired depths, 'bent-thermocouples' with their tips of 4 and 8mm bent at $120^{\circ}$ were used. The profiles of temperature variation were recorded continuously at one second interval using a thermometer with memory function (Fluke Co. U.S.A.) and 0.7mm thermocouples (Omega Co., U.S.A.). To simulate typical clinical conditions, 35mm square samples of bovine scapular bone were utilized. The samples were approximately 20mm thick with the cortical thickness on the drilling side ranging from 1 to 2mm. A sample was placed in a container of saline solution so that its lower half is submerged into the solution and the upper half exposed to the room air, which averaged $24.9^{\circ}C$. The temperature of the saline solution was maintained at $36.5^{\circ}C$ using an electric heater (J. O Tech Co., Korea). This experimental condition was similar to that of a patient s opened mouth. The study revealed that a 2mm twist drill required greatest attention. As a guide drill, a twist drill is required to bore through a 'virgin bone,' rather than merely enlarging an already drilled hole as is the case with other drills. This typically generates greater amount of heat. Furthermore, one tends to apply a greater pressure to overcome drilling difficulty, thus producing even greater amount heat. 150 experiments were conducted for 2mm twist drill. For 140 cases, drill pressure of 750g was sufficient, and 10 cases required additional 500 or 100g of drilling pressure. In case of the former. 3 of the 140 cases produced the temperature greater than $47^{\circ}C$, the threshold temperature of degeneration of bone tissue (1983. Eriksson et al.) which is also the reference temperature in this study. In each of the 10 cases requiring extra pressure, the temperature exceeded the reference temperature. More significantly, a surge of heat was observed in each of these cases This observations led to addtional 20 drilling experiments on dense bones. For 10 of these cases, the pressure of 1,250g was applied. For the other 10, 1.750g were applied. In each of these cases, it was also observed that the temperature rose abruptly far above the thresh old temperature of $47^{\circ}C$, sometimes even to 70 or $80^{\circ}C$. It was also observed that the increased drilling pressure influenced the shortening of drilling time more than the rise of drilling temperature. This suggests the desirability of clinically reconsidering application of extra pressures to prevent possible injury to bone tissues. An analysis of these two extra pressure groups of 1,250g and 1,750g revealed that the t-statistics for reduced amount of drilling time due to extra pressure and increased peak temperature due to the same were 10.80 and 2.08 respectively suggesting that drilling time was more influenced than temperature. All the subsequent drillings after the drilling with a 2mm twist drill did not produce excessive heat, i.e. the heat generation is at the same or below the body temperature level. Some of screw tap, pilot, and countersink showed negative correlation coefficients between the generated heat and the drilling time. indicating the more the drilling time, the lower the temperature. The study also revealed that the drilling time was increased as a function of frequency of the use of the drill. Under the drilling pressure of 750g, it was revealed that the drilling time for an old twist drill that has already drilled 40 times was 4.5 times longer than a new drill The measurement was taken for the first 10 drillings of a new drill and 10 drillings of an old drill that has already been used for 40 drillings. 'Test Statistics' of small samples t-test was 3.49, confirming that the used twist drills require longer drilling time than new ones. On the other hand, it was revealed that there was no significant difference in drilling temperature between the new drill and the old twist drill. Finally, the following conclusions were reached from this study : 1 Used drilling bur causes almost no change in drilling temperature but increase in drilling time through 50 drillings under the manufacturer-recommended cooling conditions and the drilling pressure of 750g. 2. The heat that is generated through drilling mattered only in the case of 2mm twist drills, the first drill to be used in bone drilling process for all the other drills there is no significant problem. 3. If the drilling pressure is increased when a 2mm twist drill reaches a dense bone, the temperature rises abruptly even under the manufacturer-recommended cooling conditions. 4. Drilling heat was the highest at the final moment of the drilling process.