잡음을 고려한 전기비저항 탐사 자료의 역산

안동국,조인기 한국자원공학회 2009 한국자원공학회지 Vol.46 No.5

The major sources of noise in DC resistivity measurement are high contact resistance, measurement errors, and sporadic background noise. Accurate quantification of data noise is crucial to prevent misinterpretation of resistivity data. Stacking repeated measurements is useful for minimizing random errors. Reciprocal measurements can provide a measure of data precision. Stacking and reciprocal measurements are both useful in estimating noise. Fortunately, most of modern resistivity devices measures standard deviation of data noise. However, the measured noise, especially in Korea, has generally been used only for the data quality control in the data acquisition stage. In this study, we propose a noise estimation and data weighting method according to noise level. Through numerical tests, we assure that accurate noise estimation and data weighting according to noise level effectively suppress the effects of noise without degrading resolving power. 전기비저항 탐사에서 잡음원은 높은 접촉저항, 장비의 측정오차 및 주변의 불규칙한 잡음을 들 수 있다. 전기비저항 탐사 자료의 올바른 해석을 위해서는 이들 잡음의 정확한 추정이 필요하다. 반복성시험은 불규칙 잡음을 억제하는데 효과적이며, 상반성시험은 측정자료의 정밀도를 제공해 준다. 또한 이들 반복성시험과 상반성시험은 잡음의 측정에 매우 효과적이다. 최근 전기비저항 탐사기기들은 잡음자료의 표준편차를 제공한다. 하지만 국내의 경우 이 잡음을 현장자료획득 단계에서 자료의 질을 평가하는데 사용하는데 그치고 있다. 본 연구에서는 정확한 잡음측정방법과 잡음수준에 자료가중값을 결정하는 방법을 제안하였다. 수치실험을 통하여 정확한 잡음측정과 잡음에 따른 가중값을 사용할 경우 역산의 분해능 저하 없이 잡음의 영향을 효과적으로 억제할 수 있음을 확인하였다.

Periaqueductal gray에서 enkephalin, glutamate 및 GABA성 약물이 개구반사에 미치는 영향

안동국,성재현,박재식,이원정,주영은 대한구강생물학회 1991 International Journal of Oral Biology Vol.15 No.1

This study was performed to evaluate what neurotransmitters are involved in pain modulation of periaqueductal gray matter(PAG) by observing responses of jaw opening reflex to iontophoretically applied neurotransmitters at PAG. Jaw opening reflex was used as a reponse to pain Wistar rats were anesthetized with urethane and α-chloralose solution. Bipolar EMG electrodes were inserted into left anterior digastric muscle to record the effect of neurotransmitters at PAG on reflex evoked by electrical palatal stimulation. then the rat's head was placed in a stereotaxic frame. PAG area was exposed and then the tip of iontophoretic microelectrodes were placed at PAG for injection of neurotransmitters. Bipolar stimuli were delivered to the ipsilateral palatal mucosa. The intensity of the noxious stimulus was twice or three times as much as the threshold which induced the minimal dEMG(digastric electromyogram) activity. Met-enkepalin, sodium L-glutamate GABA or naloxone was applied by current injection(150nA, 1min) or pressure injection(15psi, 30sec or 1min). Between injection of drugs, retaining currents of 10nA were passed. The magnitude of dEMG in reponses to electrical palatal stimulation was decreased after injection of met-enkephalin or L-glutamate. The responses of dEMG to pressure injection of met-enkephalin were dose-dependent. Current or pressure injection of met-enkephalin suppressed the dEMG about the same magnitude. Naloxone injected iontophoretically into PAG antagonized antinociceptive effect of met-enkephalin and it was reversible. But naloxone had no effect on the glutamate induced antinociception. Injection of GABA at PAG produced an insignificant changes in dEMG. These results indicate that met-enkephalin and L-glutamate at PAG shows analgesic effect on the jaw opening reflex test. But considering effects of naloxone, these analgesic mechanisms are different in each case.

Intracisternal Administration of Voltage Dependent Calcium Channel Blockers Attenuates Orofacial Inflammatory Nociceptive Behavior in Rats

안동국 KOREAN ACADAMY OF ORAL BIOLOGY 2011 International Journal of Oral Biology Vol.36 No.2

Voltage dependent calcium channel (VDCC), one of the most important regulator of Ca 2+ concentration in neuron, play an essential role in the central processing of nociceptive information. The present study investigated the antinociceptive effects of L, T or N type VDCC blockers on the formalin-induced orofacial inflammatory pain. Experiments were carried out on adult male Sprague-Dawley rats weighing 220-280 g. Anesthetized rats were individually fixed on a stereotaxic frame and a polyethylene (PE) tube was implanted for intracisternal injection. After 72 hours, 5% formalin (50 μL) was applied subcutaneously to the vibrissa pad and nociceptive scratching behavior was recorded for nine successive 5 min intervals. VDCC blockers were administered intracisternally 20 minutes prior to subcutaneous injection of formalin into the orofacial area. The intracisternal administration of 350 or 700 μg of verapamil, a blocker of L type VDCC, significantly decreased the number of scratches and duration in the behavioral responses produced by formalin injection. Intracisternal administration of 75 or 150 μg of mibefradil, a T type VDCC blocker, or 11 or 22 μg of cilnidipine, a N type VDCC blocker, also produced significant suppression of the number of scratches and duration of scratching in the first and second phase. Neither intracisternal administration of all VDCC blockers nor vehicle did not affect in motor dysfunction. The present results suggest that central VDCCs play an important role in orofacial nociceptive transmission and a targeted inhibition of the VDCCs is a potentially important treatment approach for inflammatory pain originating in the orofacial area.

Participation of Peripheral P2X Receptors in Orofacial Inflammatory Nociception in Rats

안동국 KOREAN ACADAMY OF ORAL BIOLOGY 2011 International Journal of Oral Biology Vol.36 No.3

The present study investigated the role of peripheral P2X receptors in inflammatory pain transmission in the orofacial area in rats. Experiments were carried out on male Sprague- Dawley rats weighing 220 to 280 g. Formalin (5%, 50 μL) and complete Freund's adjuvant (CFA, 25 μL) was applied subcutaneously to the vibrissa pad to produce inflammatory pain. TNP-ATP, a P2X2,2/3,4 receptor antagonist, or OX-ATP, a P2X7 receptor antagonist, was then injected subcutaneously at 20 minutes prior to formalin injection. One of the antagonists was administered subcutaneously at three days after CFA injection. The subcutaneous injection of formalin produced a biphasic nociceptive behavioral response. Subcutaneous pretreatment with TNP-ATP (80, 160 or 240 μg) significantly suppressed the number of scratches in the second phase produced by formalin injection. The subcutaneous injection of 50 μg of OX-ATP also produced significant antinociceptive effects in the second phase. Subcutaneous injections of CFA produced increases in mechanical and thermal hypersensitivity. Both TNP-ATP (480 μg) and OX-ATP (100 μg) produced an attenuation of mechanical hypersensitivity. However, no change was observed in thermal hypersensitivity after the injection of either chemical. These results suggest that the blockade of peripheral P2X receptors is a potential therapeutic approach to the onset of inflammatory pain in the orofacial area.

근관 치료 후 수복 방법이 파절 강도와 파절 양상에 미치는 영향

안동국(Dong-Gook An),조인호(In-Ho Cho),신수연(Soo-Youn Shin) 대한턱관절교합학회 2005 구강회복응용과학지 Vol.21 No.2

약품 활성화에 의한 매실씨 활성탄의 제조

김경호,안동국,김영재,김학희 한국공업화학회 2006 한국공업화학회 연구논문 초록집 Vol.2006 No.1

고속핵에서 GABA가 동맥압에 미치는 영향

이정헌,오기화,안동국,박재식 慶北大學校 醫科大學 1996 慶北醫大誌 Vol.37 No.3

목적 : NTS (nucleus tractus solitarius)는 압감수성 반사 구심성 신경이 처음 시냅스를 형성하는 곳으로 동맥압 조절에 중요한 역할을 한다. NTS에서 어떤 특정 물질이 동맥압 조절에 관여하는지는 정확히 밝혀지지는 않았지만, NTS에 존재하는 많은 물질들이 이들 과정에 관여하고 있다. 그중 하나인 GABA성 약물이 NTS에서 순환계에 미치는 영향을 구명하고자 본 실험을 시행하였으며 아울러 반대편 NTS를 lidocaine으로 억제하였을 경우의 변화를 관찰하여 NTS에서 신경회로 일단을 밝히고자 하였다. 대상 및 방법 : 실험동물은 체중 300-500g 되는 숫컷 Wistar쥐를 사용하였다. 동맥압 측정과 약물 주입을 위하여 대퇴 동정맥에 삽관하였다. 이어서 기관지절개술을 시행하였으며 체온을 36-37℃ 되게 열판을 이용하여 조절하였다. 쥐를 뇌 정위 고정 장치에 두고 머리를 45°숙여 NTS를 노출시킨 다음 약물을 10초간에 걸쳐 80nl주입하였다. 결과 : 인공 뇌척수액을 주입하면 동맥압의 변화가 거의 없었으나 동량의 GABA를 NTS에 주입하면 동맥압이 증가하였다. GABA에 의해 동맥압이 증가된 상태에서 반대측 NTS에 lidocaine을 주입하여 한쪽 기능을 억제시키면 동맥압이 더욱 증가하였다. 또한 lidocaine주입 후 반대쪽의 건전한 NTS에 GABA를 재차 주입하면 동맥압 증가가 적었다. 그리고 GABA를 NTS에 주입 후 정맥으로 nitroprusside를 주입하면 GABA 주입이 없는 대조군에 비해 동맥압 감소가 더 컸으며, lidocaine으로 마취하여 한쪽 NTS의 기능을 차단한 후 반대쪽 건전한 NTS에 GABA를 주입한 경우는 동맥압 감소가 적었다. 동일한 방법으로 lidocaine을 주입한 후 phenylephrine으로 승압을 시키면 동맥압 증가가 적었다. 압감수성 반사는 NTS에 GABA를 주입하거나 또는 반대편 NTS를 lidocaine으로 마취하여 기능을 억제시킨 경우에 둔화되었다. 결론: NTS에서 GABA가 동맥압의 조절 인자로 작용하며, 양쪽 NTS는 상호작용하고 있는 것으로 보인다. The nucleus tractus solitarius (NTS), the site of termination within the brain of baroreceptor afferent fibers, has been shown to be involved in the regulation of arterial pressure (AP). Many neuroactive substances present within the NTS have been shown to be involved in this process, although the manner in which any specific neurotransmitter acts physiologically in the regulation of AP has not been completely elucidated. The present study was intended to clarify the mechanism of action of GABA in the NTS and also to examine the cardiovascular response to inhibition of the contralateral NTS by lidocaine. Male Wistar rats weighing 300-500 g were employed for the experiment. The femoral artery and vein were cannulated to record the arterial pressure (AP) and to inject nitroprusside or phenylephrine, respectively. The tracheotomy was performed and body temperature was kept to 36-37℃. Rats were mounted in a stereotaxic frame with the head flexed downward to an angle of 45°. After the NTS was exposed. GABA or lidocaine was microinjected into the NTS in a volume of 80 nl over 10 seconds through a glass micropipette (outer diameter of the tip 50 ㎛) connected to a 1 ㎕ Hamilton microsyringe. The results obtained are summarized as follows. Microinjection of artificial CSF into the ipsilateral NTS did not alter basal AP. In contrast, microinjection of the same volume of GABA into the NTS produced a significant increase in the AP. The results presented thus far indicated that the volume injected did not affect AP. In animals with elevated AP by GABA injection, injection-of lidocaine into the contralateral NTS resulted in a further increase in AP. After the contralateral NTS was inhibited with lidocaine. injection of GABA into the NTS produced a less increase in AP. After microinjection of GABA into the NTS, the nitroprusside administered i.v. accentuated the increase of AP but not after microinjection of lidocaine into the contralateral NTS. Similar results were obtained with i.v. injection of phenylephrine after pretreatment of lidocaine into the NTS. The baroreflex sensitivity was reduced by microinjection of GABA into the NTS or microinjection of lidocaine into the contralateral NTS. These results suggest that alterations in GABA-mediated neural transmission in the NTS contribute to the regulation of AP and the NTS of both sides have a mutual interaction.

경막내로 투여한 신경전달물질이 통증성 배뇨반사에 미치는 영향

박재식,김덕윤,안동국 大韓泌尿器科學會 1998 Korean Journal of Urology Vol.39 No.8

측뇌실에서 고농도 Na^+에 대한 고농도 Ca^++의 심혈관계 영향

최애경,김경순,안동국,박윤엽,박재식 慶北大學校 醫科大學 1995 慶北醫大誌 Vol.36 No.2

목적 : 고농도의 NaCl 용액을 측뇌실에 주입하여 동맥압 및 심박수의 변화를 관찰하고, 또한 Ca^++을 전처치한 후 NaCl 용액을 주입하여 역시 동맥압과 심박수를 관찰하여 이들의 상호 관계를 알아보았다. 대상 및 방법 : 체중 340∼480g의 Wistar 숫쥐를 마취한 후 뇌정위 고정 장치에 쥐를 고정하고 측뇌실에 관을 삽입하였다. 수술후 5일이 경과한 다음 대회동맥에 관을 삽입한 후 깨어있는 상태에서 측뇌실에 용액을 2㎕/min의 속도로 주입하였다. 출혈 실험에서 출혈은 빠른 시간내에 1.5㎖/100g BW으로 하였다. 결과 : 960mOsm/l NaCl 용액 주입에 의해 동맥압은 증가하고 심박수는 감소하였다. Ca^++을 전처치한 후 NaCl을 주입한 경우에도 동맥압은 증가하고 심박수는 감소하였지만 NaCl 단독으로 주입한 경우보다는 동맥압의 증가가 둔화되었다. NaCl 용액 주입후 출혈을 시키면 대조군에 비해 동맥압 감소가 적었으며 심박수의 증가는 컸다. 그러나 Ca^++을 전처치한 후 NaCl을 주입하여 출혈시킨 경우는 동맥압 및 심박수 변화가 대조군과 비슷하였다. 출혈시 압감수성 반사는 NaCl 주입군에서 가장 큰 경향을 보였다. 한편 혈장 renin은 NaCl 주입군에서 대조군보다 낮았으며, Ca^++을 전처치한 후 NaCl 주입한 군에서는 대조군보다는 낮았지만 NaCl을 단독으로 투여한 군보다는 높았다. 혈장 AVP는 NaCl 주입군이 대조군보다 높았다. 결론 : 측뇌실내 고농도의 Na^+은 교감신경 활성도를 촉진시켜 동맥압을 상승시키며, Ca^++은 교감신경을 억제하여 Na^+와 반대되는 작용을 나타내었다. The contribution of the central interaction between calcium and sodium ions to hemodynamic regulation was assessed in Wistar rats. The effect of a high calcium solution (Ca^++, 130 ㎎/㎗, infused into the cerebral ventricle (i.c.v.) on hemodynamic responses induced by i.c.v. high sodium (Na^+, 960mOsm/1, 20㎕) was studied. And also the effect of hemorrhage on the cardiovascular response was investigated. Under pentobarbital anesthesia, stainless steel cannula (22 gauge) was implanted stereotaxically in a lateral cerebral ventricle according to Paxinos' brain atlas. After a 5-day recovery period, the femoral artery was catheterized, under thiopental anesthesia, with PE50 tubing filled with heparinized saline. Upon recovery, high NaCl solution was infused into the lateral ventricle through the cannula at a rate of 2㎕/min for 10 min. After the mean arterial pressure and heart rate had returned to their baseline values, high Ca^++, followed shortly by a second dose of high Na^+, was administered centrally. Acute hemorrhage (1.5㎖/100) was induced before and after infusion of NaCl solution and after infusion of Ca^++ pretreated NaCl solution. High i.c.v. Na^+ increased the MAP, but decreased the HR. Prior treatment with i.c.v. high Ca^++ reduced the pressor reponse to high Na^+ i.c.v. Treatment with high NaCl solution resulted in a less decrease in MAP caused by hemorrhage. After pretreatment with high Ca^++, however, MAP de creased to the same level as in the control group in response to hemorrhage. Plasma renin activity was lowered and arginine vasopressin elevated in high Na^+ group. These results suggest that high Na^+ in the lateral ventricle produces an increase in MAP by increasing the sympathetic nervous system activity. In this respect, high Na^+ might be helpful in recovering from blood loss. Also, central Ca^++ antagonizes the pressor response to central Na^+ by inhibiting the sympathetic nervous system activity. Central Ca^++, therefore, may have importance in the control of hypertension.

Effect of local anesthesia on pulpal blood flow in mechanically stimulated teeth

Chu, Wan-Sik,Park, Seung-Ho,Ahn, Dong-Kuk,Kim, Sung-Kyo 大韓齒科保存學會 2006 Restorative Dentistry & Endodontics Vol.31 No.4

에피네프린을 함유한 국소마취제가 치수혈류량에 미치는 영향을 관찰하고, 이 국소마취가 와동 형성에 의해 야기되는 치수의 혈류변화에 미치는 영향을 평가하고자 전신마취된 아홉 마리의 고양이 견치에서 1 : 100,000 에피네프린이 함유된 2% 리도카인 용액으로의 국소 침윤마취 전후 및 와동형성 전후의 치수혈류를 laser Doppler flowmetry (Periflux4001, Perimed Co., Sweden)를 사용하여 측정하고 paired t-test로 통계분석하였다. 상아질 와동의 형성은 치수혈류의 현저한 증가를 초래하였다 (p < 0.05). 에피네트린을 함유한 리도카인의 침윤마취는 치수혈류를 유의하게 감소시켰다 (p < 0.05). 국소마취한 치아에서는 마취도지 않은 치아에 비해 와동형성시 유의하게 적은 치수혈류의 증가를 나타내었다 (p < 0.05). 따라서 본 연구에서는 혈관수축제를 포함한 국소마취가 와동 형성에 의해 초래되는 혈류량의 증가를 효과적으로 억제 할 수 있음을 보여주고 있다. The aims of the study were to evaluate the effect of epinephrine-containing local anesthetics on pulpal blood flow (PBF) and to investigate its effect on cavity preparation-induced PBF change. PBF was recorded using a laser Doppler flowmeter (Perimed Co., Sweden) from canines of nine cats under general anesthesia before and after injection of local anesthetics and after cavity preparation. 2% lidocaine hydrochloride with 1 : 100,000 epinephrine was administered by local infiltration given apical to the mandibular canine at the vestibular area and the same volume of isotonic saline was injected on the contralateral tooth as a control. A round carbide bur was operated at slow speed with isotonic saline flushing to grind spherical cavities with increasing depth through the enamel and into the dentin on both teeth. The obtained data was analyzed with paired t-test. Cavity preparation caused significant increase of PBF (n = 9, p < 0.05). Local infiltration of lidocaine with epinephrine resulted in decreases of PBF (n = 9, p < 0.05), whereas there was no significant change of PBF with the physiologic saline as a control. Cavity preparation on tooth anesthetized with lidocaine with epinephrine caused significantly less increase of PBF than in control tooth (p < 0.05). Therefore, the result of the present study demonstrates that local infiltration of 2% lidocaine with 1 : 100,000 epinephrine effectively reduces PBF increase caused by cavity preparation. 〔J Kor Acad Cons Dent 31(4):257-262, 2006〕