An Unexpected Observation : Synthesis of a Novel Polyimide form Bis(trimethylsilyl)urea and Dianhydride

Jung, Byung Te,Choi, HoWook,Park, Kyung Sun,Suh, Dong Hack 한국공업화학회 2003 Journal of Industrial and Engineering Chemistry Vol.9 No.2

The polyimidization of bis(trimethylsiIyl)urea with 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) in dimethylsulfoxide (DMSO) was carried out to produce a novel polyimide. New structure of polyimide was characterized by ¹H-NMR and FT-lR spectrum. The polymer has inherent viscosity of 0.385 dL/g and was stable up to at least 430℃ with 10% weight loss. A wide-angle X-ray diffractogram revealed that the polymer was semi-crystalline.

경한 상기도 감염증상이 있는 소아의 수술시 기도합병증의 빈도

박정구,최규택,서병태 대한마취과학회 1995 Korean Journal of Anesthesiology Vol.29 No.3

A prospective study of 99 pediatric patients were performed to investigate the incidence of perioperative airway complications presenting for various surgery with mild upper respiratory infections(URI's). Anesthesia administered via either face mask or endotracheal intubation. The severity of respiratory complications were scored. Endotracheal intubation in itself increased complication score compared to inhalation anesthesia with face mask. There were significant differences in the complication scores between control children and children fulfilling predetermined URI criteria. Complications showing significant differences were cough, airway obstruction, secretion. However, mean scores were too low to draw conclusion that children with URI's should be postponed elective surgery.

흉추 경막외 차단후 전신마취병행시 혈역학 변화

이동명,최규택,박정원,서병태,임태하 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.33 No.3

Background : It has been a standard practice in many institutions to combine light general anesthesia with epidural block for abdominal and pelvic surgery. We attempted to prove the effectiveness of prehydration and to find an suitable epidural local anesthetic dose in terms of hemodynamic stability for upper abdominal surgery. Methods : For preliminary studies, 11 patients scheduled for elective upper abdominal surgery had received general anesthesia immediately after epidural anesthesia. After epidural injection of 10∼16 mL of 2% plain lidocaine into the T9∼10 intervertebral space, the changes in blood pressure were observed. Thirty-two patients scheduled for elective upper abdominal surgery were divided into two groups. In group A(study group), after prehydration with Hartmann solution(10 mL/kg), 5∼7 mL of 2% plain lidocaine was injected into T8∼9 or T9∼10 intervertebral space and general anesthesia was then induced. Group B(control group) received general anesthesia only. Results : There were no signnt differences in hemodynamics between the epidural with general anesthesia and the control group except SVR(systemic vascular resistance). SVR in group A increased in contrast to the group B in which it remained unchanged. Conclusions : The combined epidural and general anesthesia, using prehydration and 0.5∼1 mL/segment of 2% plain lidocaine at the T8∼9 or T9∼10 intervertebral space was safe without significant hemodynamic changes. (Korean J Anesthesiol 1997; 33: 472∼476)

흰쥐 횡경막 신경근 표본에서 Aminophylline이 Atracurium의 용량반응곡선에 미치는 영향

양홍석(Hong Seok Yang),정화성(Wha Sung Jung),박숙희(Sook Hee Park),이정석(Jung Seok Lee),박태성(Tae Sung Park),서병태(Byung Te Suh) 대한마취과학회 1999 영문부록 Vol.- No.-

Background : Aminophylline improves contractility of respiratory muscles and antagonizes action of nondepolarizing neuromuscular relaxant, in vivo. This study was designed to investigate the interaction of aminophylline and atracurium on the dose-response curve, in vitro. Methods : Forty male Spague Dawley rats (150∼200 g) were divided into four groups (control, aminophylline 5, 10 and 20μg/ml). Animals were anesthetized with 40 mg/kg thiopental sodium. The left hemidiaphragm with phrenic nerve was dissected and mounted within a bath containing 100 ml Krebs solution at 32oC. The phrenic nerve was stimulated at supramaximal intensity by stimulator through an isolation unit. Twitch height was measured by precalibrated force displacement transducer and recorded. After stabilization of twitch response, atracurium was added to the solution to obtain an initial concentration of 10 μg/ml with aminophylline 0, 5, 10, or 20μg/ml. When a stable 3∼5 twitch was obtained after first dose, additional atracurium was added to the Krebs solution in increments of 5μg/ml to obtain more than 90% neuromuscular block. Results : There was significant increase in the effective dose of atracurium needed to depress the twitch response in aminophylline 20 μg/ml added group. Conclusion : The dose-response curve of atracurium is shifted to right by interaction of aminophylline in the phrenic nerve diaphragm preparation of rat. (Korean J Anesthesiol 1999; 36: 1046∼1050)

An Unexpected Observation: Synthesis of a Novel Polyimide from Bis(trimethylsilyl)urea and Dianhydride

서동학,Ho Wook Choi,Kyung Sun Park,Byung Te Jung 한국공업화학회 2003 Journal of Industrial and Engineering Chemistry Vol.9 No.2

Midazolam 이 안압에 미치는 영향

김완식,박동호,황영희,김흥대,김인규,서병태,김미연,정연탁 대한마취과학회 1982 Korean Journal of Anesthesiology Vol.15 No.1

Intraocular tension may be acutely changed by many drugs and by various physiologic events. An acute rise in intracoular tension may be catastrophic if it occurs when the globe is open and leads to expulsion of contents. Most general anesthetics cause a decrease in intraocular pressure, although a few causes increased intraocular pressure. Midazolam is a 1,4-benzodiazepine derivtive synthesized by Walser and Freyer in 1975. Eariler studies with midazolam have demonstrated its efficacy for induction of anesthesia and premedication. It is also desirable to know if all anesthetic agents which produce general anesthesia and which are pharmacologically different affect intraocular pressure in a similar manner. Therefore investigation of the influence of midazolam on intraocular pressure in 25 patients was undertaken at the Dept. of anesthesiology, Hanyang University. All patients had no known eye abnormalities. The patients were not premedicated. In all partients the intraocular pressure was measured before induction of anesthesia, after instilling a 0.5% tetracaine into the conjunctival sac. A second reading was taken after induction of midazolam (0.2 mg/kg of body weight) and a third after injection of succinylcholine (1 mg/kg of body weight) and a fourth after endotracheal intubation. A Schiotz tonometer with a 5.5 gm and a 7.5 gm weight was used. In addition to the tonometric determinations, the bood pressure, pulse rate and respiratory rate were recorded before and after induction of midazolam. An attempt was tried to keep the intraocular pressure changed as many and to minimize the other factors affecting intraocular pressure. To achieve this, supine position and constant gea flow was maintained. Special care was taken to avoid pressure on the patients eyes and to maintain a fully patent airway to prevent respiratory disturbances leading to straining and increased venous pressure. Endotracheal intubation was performed with the aid of succinylcholine to avoid cough or laryngospasm. The results of the observation with the above mentioned method were tested by student t-test statistically. Each patient acted as his own control. There was a fall in intraocular pressure in 17 patients among 25 parients (average 1.8 mmHg), but no significant change followed by the use of midazoam. The blood pressure variations were between 10 and 40 mmHg, during the course of anesthesia and could not be related to intraocular pressure changes. Intraocular pressure chagnes had no relation to pulse and respiratory rate variations. This finding indicated that benzodiazepine as a class of drugs have well described muscle relaxant properties that are primarily central (supraspinal) rather than peripheral (myoneural) in action. There was a rise in intraocular pressure in 19 patients among 25 patients, followed by the use of succinylcholine and 23 patients among 25 patients, after endotracheal intubation. According to Feldman and Crawley, diaxepam potentiated the myoneural blocking effects of gallamine and antagonizes the effects of succinylcholine. Nevertheless Dretchen demonstrated that the clinical doses of diaxepam did not potentiated the muscle relaants. Our finding showing no apparent succinylcholine interaction with midazolam are consistent with the finding of Dretche.