Yohimbine과 Atipamezole이 Xylazine-Ketamine병용 마취견의 뇌파에 미치는 영향

장환수,장광호,이만기,장인호 한국임상수의학회 2002 한국임상수의학회지 Vol.19 No.2

Effects of Medetomidine on Analgesia and Sedation in Rats

장환수,이만기 한국임상수의학회 2010 한국임상수의학회지 Vol.27 No.6

The effects of medetomidine on the degree of analgesia and sedation in rats were evaluated. The rats were randomly divided into six groups: saline, 1 mL/kg (group ‘Saline’); butorphanol, 2.0 mg/kg; medetomidine, 0.2, 0.4,0.8 or 1.6 mg/kg (group ‘MED0.2’, ‘MED0.4’, ‘MED0.8’ and ‘MED1.6’, respectively). The degree of analgesia was measured in the 50°C hot-water tail-flick latency test, and the degree of sedation was evaluated using the numerical sedation score (NSS) and the righting reflex. All doses of medetomidine, except MED0.2, significantly increased the analgesic effect compared to the Saline group. Variables in the MED0.4 and MED0.8 groups, but not in the MED1.6group, were significantly increased compared to those in the MED0.2 group. However, analgesia with all doses of medetomidine was not significantly different compared to that with butorphanol. Saline and butorphanol treatments did not induce sedation and loss of righting reflex during the recording period. NSS in the MED0.4, MED0.8 and MED1.6 groups were significantly higher than that in the MED0.2 group. NSS in the MED0.8 and MED1.6 groups were not significantly different from that in the MED0.4 group. The latency to loss of righting reflex in the MED0.8and MED1.6 groups decreased significantly compared to that in the MED0.2 group. Thus, 0.4 and 0.8 mg/kg of medetomidine provided not only reliable analgesia but also sedation to rats. In conclusion, 0.4 to 0.8 mg/kg medetomidine could be a useful chemical restraint method in rats.

Prediction of Surgical Anesthesia in Medetomidine/Tiletamine/ Zolazepam Anesthetized Dogs using Electroencephalography

장환수,김정은,권영삼,이만기,장광호,임재현 한국임상수의학회 2010 한국임상수의학회지 Vol.27 No.5

Changes of electroencephalogram (EEG), mean arterial blood pressure (MAP) and heart rate under surgical anesthesia were investigated in medetomidine (MED) and tiletamine/zolazepam (ZT)-anesthetized dogs. To determine the level of surgical anesthesia, pedal withdrawal reflex was regularly tested after ZT injection. The first time point without pain response was regarded as the beginning of surgical anesthesia (SSA). After SSA, the first time point showing positive pain response was considered the end of surgical anesthesia (ESA). Comparing the control, an additional significant decrease of δ2 and α2 was observed at SSA. Comparing the control, δ2 was significantly decreased at ESA. Significant reductions of MAP were observed at pre-ESA and ESA. Heart rate significantly decreased in all stages. These results suggest that δ2 band power is a valuable parameter for correlating surgical anesthesia in dogs anesthetized with MED and ZT.

The Effects of Tramadol on Electroencephalographic Spectral Parameters and Analgesia in Rats

장환수,장일성,이만기 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.3

The effects of different doses of tramadol on analgesia and electroencephalographic (EEG) spectral parameters were compared in rats. Saline or tramadol 5, 10, 20 or 40 mg/kg was administered. The degree of analgesia was evaluated by tail-flick latency, and the degree of seizure was measured using numerical seizure score (NSS). Additionally, band powers, median power frequency and spectral edge frequency 95 were measured to quantify the EEG response. All doses of tramadol produced spike-wave discharge. Tramadol significantly and dose-dependently increased the analgesia, but these effects did not correspond with the changes in the EEG spectral parameters. NSS significantly increased in the Tramadol 20 and 40 mg/kg treatment groups compared to the Control and TRA5 groups, and two rats given 40 mg/kg had convulsions. In conclusion, tramadol dose-dependently increased the analgesic effect, and the 10 mg/kg dose appears to be a reliable clinical dose for analgesia in rats, but dose-dependent increases in analgesia and seizure severity did not correlate with EEG spectral parameters.

Effects of Isoflurane Anesthesia on Post-Anesthetic Sleep-Wake Architectures in Rats

장환수,정지영,장광호,이만기 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.5

The sleep homeostatic response significantly affects the state of anesthesia. In addition, sleep recovery may occur during anesthesia, either via a natural sleep-like process to occur or via a direct restorative effect. Little is known about the effects of isoflurane anesthesia on sleep homeostasis. We investigated whether 1) isoflurane anesthesia could provide a sleep-like process, and 2) the depth of anesthesia could differently affect the post-anesthesia sleep response. Nine rats were treated for 2hours with ad libitum sleep (Control), sleep deprivation (SD), and isoflurane anesthesia with deltawave-predominant state (ISO-1) or burst suppression pattern-predominant state (ISO-2) with at least a 1-week interval. Electroencephalogram and electromyogram were recorded and sleep-wake architecture was evaluated for 4 hours after each treatment. In the post-treatment period, the duration of transition to slow-wave-sleep decreased but slow wave sleep (SWS) increased in the SD group, but no sleep stages were significantly changed in ISO-1 and ISO-2 groups compared to Control. Different levels of anesthesia did not significantly affect the post-anesthesia sleep responses, but the deep level of anesthesia significantly delayed the latency to sleep compared to Control. The present results indicate that a natural sleep-like process likely occurs during isoflurane anesthesia and that the post-anesthesia sleep response occurs irrespective to the level of anesthesia.

Medetomidine과 Atipamezole의 상호 작용이 개의 뇌파에 미치는 영향

장환수,장광호,이주명,강원모,박승훈,이만기,장인호 한국임상수의학회 2001 한국임상수의학회지 Vol.18 No.3

We investigated the effects of interactions of medetomidine and atipamezole on electroencephalography (EEG) in seven dogs. The dogs were sedated with medetomidine at dose of 30$\mu\textrm{g}$/kg, IM. Atipamezole was injected 15 min later at dose of 30$\mu\textrm{g}$/kg, IV. Recording electrode was positioned at Cz, which was applied to International 10-20 system. Heart rates, arterial blood pressures and behavioral changes were also measured. EEG was recorded in 6 stages(S1: before medetomidine injection, S2: prior to head-down movement after medetomidine injection, S3: 5 minutes after medetomidine injection, S4: 10 minutes after medetomidine injection, S5: 15 minutes after medetomidine injection, S6: prior to head-up movement after atipamezole injection), and heart rates and arterial pressures were recorded at S1, S5 and S6. All results were compared with those of control(S1). After medetomidine injection, the power spectra of EEG were gradually decreased and those of the frequency over 13 Hz were significantly decreased(p<0.05), which were still in the significantly decreased state after atipamezole injection. In the band powers (Band1; 1-2.5 Hz, Band2; 2.5-4.5 Hz, Band3; 4-8Hz, Band4; 8-13 Hz, Band5; 13-20 Hz, Band6; 20-30 Hz, Band7; 30-50 Hz, Band8; 1-50 Hz), band 1, 2, 3, 4, 8 were not significantly changed in any stages. Band 5, 6, 7 were significantly decreased in S 3, 4, 5, 6. That is, medetomidine affects the frequency band over 13 Hz on EEG, and atipamezole does not restored the decreased band powers until dogs showed head-up movement.

Combined Therapy with Carboplatin and Meloxicam for Oral Squamous Cell Carcinoma in a Dog

장환수,김준일,김재훈,장광호 한국임상수의학회 2011 한국임상수의학회지 Vol.28 No.3

A 16-year-old, spayed female, Maltese dog weighing 4.3 kg was presented with a 2-week history of yellowish nose-and oral-discharge, anorexia and lethargy. In physical examination, indefinite ulcerative mass about 3 × 3 cm in size in the left sublingual region, severe gingivoperiodontitis, halitosis, moderate dental calculus, fever and swelling of mandible soft tissue were noted. In radiographic view, periodontitis and bone lysis findings on the left rostral part of maxilla and mandible were observed. In complete blood count and blood chemistry test, thrombocytosis, increased levels of serum NH3, AST and ALP were obtained. Urinalysis revealed hematuria and proteinuria. In histological examination, squamous cell carcinoma was diagnosed. No surgery was performed, but combined treatment with carboplatin and piroxicam was initiated. Five days after initiation of medication, because of insistent vomiting, piroxicam was substituted to meloxicam. Although the therapeutic efficacy of meloxicam could not be known; administration of meloxicam might be less potential to gastrointestinal side-effects than piroxicam. The dog totally received 3 times of carboplatin infusion. Five days after third infusion of carboplatin, the dog was hospitalized with severe lethargy,vomiting and bloody diarrhea. In examination, severe renal failure signs were noted, and the dog was euthanized.

Role of Dopamine Receptors on Electroencephalographic Changes Produced by Repetitive Apomorphine Treatments in Rats

장환수,김지영,김상현,이만기 대한약리학회 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.3

Repeated psychostimulants induce electroencephalographic (EEG) changes, which reflect adaptation of the neural substrate related to dopaminergic pathways. To study the role of dopamine receptors in EEG changes, we examined the effect of apomorphine, the dopamine D1 receptor antagonist, SCH-23390, and the D2 receptor antagonist, haloperidol, on EEG in rats. For single and repeated apomorphine treatment groups, the rats received saline or apomorphine for 4 days followed by a 3-day withdrawal period and then apomorphine (2.5 mg/kg, i.p.) challenge after pretreatment with saline, SCH-23390, or haloperidol on the day of the experiment. EEGs from the frontal and parietal cortices were recorded. On the frontal cortex, apomorphine decreased the power of all the frequency bands in the single treatment group, and increased the theta (4.5∼8 Hz) and alpha (8∼13 Hz) powers in the repeated treatment group. Changes in both groups were reversed to the control values by SCH-23390. On the parietal cortex, single apomorphine treatment decreased the power of some frequency bands, which were reversed by haloperidol but not by SCH-23390. Repeated apomorphine treatment did not produce significant changes in the power profile. These results show that adaptation of dopamine pathways by repeated apomorphine treatment could be identified with EEG changes such as increases in theta and alpha power of the frontal cortex, and this adaptation may occur through changes in the D1 receptor and/or the D2 receptor.

사용자 공정성을 위한 MU-MIMO 시스템에서 반직교 사용자 선택 알고리즘에 중첩 코딩 적용 연구

장환수,김경훈,최승원 (사)디지털산업정보학회 2014 디지털산업정보학회논문지 Vol.10 No.1

Nowadays, various researches fulfill in many communication engineering area for B4G(Beyond Forth Generation). Next LTE-A (Long Term Evolution Advanced), MU-MIMO(Multi-User Multi Input Multi Output) method raises to upgrade throughput performance. However, the method of user selection is not decided because of many types and discussionsin MU-MIMO system. Many existing methods are powerful for enhancing performance buthave various restrictions in practical implementation. Fairness problem is primary restrictionin this area. Existing papers emphasis algorithm to increase sum-rate but we introduce analgorithm about dealing with fairness problem for real commercialization implementation. Therefore, this paper introduces new user selection method in MU-MIMO system. Thismethod overcomes a fairness problem in SUS (Semiorthogonal User Selection) algorithm. Wecan use the method to get a similar sum-rate with SUS and a high fairness performance. And this paper uses a hybrid method with SC-SUS (Superposition Coding SUS) algorithmand SUS algorithm. We find a threshold value of optimal performance by experimentalmethod. We show this performance by computer simulation with MATLAB and analysis thatresults. And we compare the results with another paper’s that different way to solve fairnessproblem.

Propofol이 개의 뇌파에 미치는 영향

장환수,장광호,채형규,권은주,김정은 한국임상수의학회 2000 한국임상수의학회지 Vol.17 No.2

The aim of this study was to evaluate the effects of propofol on cortical electroencephalogram (EEG) in seven dogs. Propofol infusion was accomplished from low concentration to high concentration in series, and each concentration was infused for 20 minutes (M0: 0, M0.5: 0.5, M1.0:1.0, and M1.5: 1.5 mg/kg/min of infusion rate). EEG was recorded via needle electrode placed at Cz, which was applied to International 10-20 system. Arterial blood pressure. blood gas analysis and ECG were also measured. Hoemodynamics, Pa$CO_2$, PaO$_2$, heart rate and respiratory rate were variable, but were net significant(p>0.05). The power spectra of EEG in every concentration was compared wish those of control (MO). The powers at a1l frequencies at M1.0 and Ml.5 were decreased. Especially, the powers of the frequencies over 20 Hz were significantly decreased (p<0.O5). Powers at frequencies between 8 and 15Hz at MO.S were significantly increased (p<0.05) in response to the painful stimuli. It was inferred that they may reflect activity of the brain which is consciously processing the external Stimuli. Like the Power spectra, al1 the band powers of He EEG ($\delta$ 1-4, $\theta$4-8, $\alpha$ 8-13, $\beta$L13-21. $\beta$H 21-30, \ulcorner 30-50, and total 1-5OHz) were decreased in proportion to the increase of infusion rate at M1 .0 and M1.5. Especially, decrease of $\beta$H and ${\gamma}$ were significant(p<0.01). At M0.5, $\alpha$ band was significantly increased(p<0.05) among all the bands. Seizure activities which were concide with occurrence of spike wave were shown in all dogs at Ml .0 and M1.5.