Protein phosphorylation involved in psychedelic-induced head-twitch response in rats / 中国药理学通报

Aim To investigate the potential protein post-translational modifications of psychedelic-induced Head-twith response and underling mechanism. Methods Psychedelics LSD, DOM, or Psilocin was administered to rats by intraperitoneal injection to induce head-twitch response, then the most effective dosage was identified to create animal models of head-twitch behavior. Western blot was performed in detecting the protein phosphorylation, acetylation, and ubiquitination in prefrontal cortex of SD rats after 10 min or 30 min injection. Results LSD (0.025 mg • kg~, i. p.), DOM (3 mg•kg

Influence of Calcium Concentration on the Neuromuscular Effects of Vecuronium on the Hemidiaphragm-Phrenic Nerve of Rats / 대한마취과학회지

BACKGROUND: Calcium disturbance may clinically produce diaphragmatic weakness. Extracellular calcium is necessary for diaphragmatic contraction, suggesting that the diaphragm behaves more like cardiac muscle. The effect of extracellular Ca2 concentrations on the relaxation action of vecuronium was studied in rat hemidiaphragm-phrenic nerve preparations. METHODS: Hemidiaphragm-phrenic nerve preparations were obtained from male Sprague-Dawley rats (200 300 g). Preparations were bathed in Kreb's solution of (mM): NaCl 118, KCl 5, CaCl2 2.5, NaHCO3 30, KH2PO4 1, MgCl2 1 and glucose 11, then maitained at 37oC when aspirated with a mixture of 95% O2 and 5% CO2. Isometric forces generated in response to 0.1 Hz, 2 Hz for 2 seconds and, 50 Hz for 2 seconds with supramaximal electrical stimulation (0.2 msec, rectangular) to the phrenic nerve, were measured with a force transducer. Single twitch tension and peak tetanic tension were calculated as a percentage of control. TOF fade was calculated as (1-(T4/T1))x100. Each preparation was exposed to the alterations in calcium concentrations of the Kreb's solution (3.75, 3.125, 1.5, 1.25, 0.625, 0.3125 (mM)), and the adequate volume of vecuronium stock solution was added to the tissue bath for desired bath concentration. The effects of calcium and vecuronium were allowed to reach a steady state before measurement of tension parameters was done. Single twitch tensions or peak tetanic tensions, which were measured at each calcium concentration, were compared respectively. EC5, EC25, EC50, EC75, and EC95 of vecuronium for a single twitch tension, TOF fade, and peak tetanic tension at each calcium concentration, were calculated using a sigmoid Emax model. We compared the EC50 of vecuronium according to calcium concentrations. Data was compared by the Kruskal-Wallis test with a post hoc Wilcoxon rank sum test. A p-value of below 0.05 was considered significant. RESULTS: The range of calcium concentration studied didn't produce differences among single or tetanictensions respectively. The EC50's of vecuronium decreased as calcium concentration decreased. CONCLUSIONS: The reduction of calcium concentration can augment the action of vecuronium on the diaphragm.

Evaluation of Presynaptic Action of Depolarizing Neuromuscular Blocking Agents with Single Twitch Response in Vitro / 대한마취과학회지

BACKGROUND: This study was performed to evaluate the presynaptic effects of depolarizing neuromuscular blocking drugs by using slow and fast frequencies of indirect stimulation on partial twitch depression in vitro. METHODS: A rat phrenic nerve hemidiaphragm was dissected and was mounted in an organ bath containing an oxygenated Krebs solution. The phrenic nerve was stimulated supramaximally and the twitch response (0.1 Hz) was stabilized for at least 30 minutes. T200/T1 ratio (twitch height of the 200th stimuli divided by that of the first stimuli) at frequencies of 0.2, 0.5, 1.0, and 2.0 Hz using a drug concentration which provided approximately 20% twitch depression at 0.1 Hz was calculated. To compare T200/T1 ratios with TOF ratios, a 2.0 Hz TOF response was measured immediately after the 200th stimuli at either frequency of stimulation. RESULTS: T200/T1 ratios produced by succinylcholine (SCC) and decamethonium (C10) were located between alpha-bungarotoxin (ABX) and hexamethonium (C6), however, significant differences among the four drugs were found at 2.0 Hz. The propensity for a decrease in T200/T1 ratios at 2.0 Hz might differ from this study: C6 > C10 > SCC > ABX. T200/T1 ratios at 2.0 Hz were not different from TOF ratios. CONCLUSIONS: It is concluded that small doses of C10 have a greater presynaptic activity than that of SCC, when the observed effects in this study were compared with the result of ABX acting predominantly at postsynaptic receptors and C6 acting predominantly at presynaptic receptors.

Importance of Local Twitch Response Induced by Needling in Myofascial Pain Syndrome

OBJECTIVE: The diagnosis of myofascial pain syndrome (MPS) is commonly made by Simons' clinical diagnostic criteria which is mainly based on patients' complaints, so it is difficult to distinguish from malingering. The purpose of this study is to evaluate local twitch response by needling (LTR) as an objective diagnostic criterion of MPS. METHOD: Forty four industrial designers complaining of regional pain in neck, shoulder, or upper arm were examined by a physiatrist. If trigger point was detected, local twitch response by needling was confirmed and than severity was measured by 4 grades. Sensitivity, specificity, and positive predictive value of local twitch response was calculated with diagnosis made by Simons' clinical diagnostic criteria. Correlation between grade of local twitch response and sum of clinical features in Simons' criteria was also evaluated. RESULTS: Local twitch response by needling was corresponding with the diagnosis of MPS by Simons' criteria (sensitivity 100%, specificity 96.7%, positive predictive value 93.3%), and the severity of local twitch response was significantly associated with sum of clinical features in Simons' criteria (Spearman correlation 0.950; p=0.048) CONCLUSION: Local twitch response by needling is an important and objective diagnostic criterion of MPS.

The Neuromuscular Effects of Succinylcholine, Mivacurium and Vecuronium Corresponding to the Blood Flow Occlusion of Time in the Isolated Forearm / 대한마취과학회지

BACKGREOUND: The magnitude of neuromuscular blockade is related to plasma concentration of muscle relaxants. This study was designed to compare the maximal depression of twitch height by blood flow occlusion using a tourniquet at various time interval after intravenous administration of muscle relaxants. METHOD: We studied 127 healthy male adult patients who underwent elective surgery under the general anesthesia with propofol infusion and 50% nitrous oxide. The single supramaximal twitch stimulation applied to the ulnar nerve at the wrist at 1 Hz. The twitch response of adductor pollicis muscles were measured by a 2 kg Load Cell strain gauge with a thumb piece modification and recorded by a Gould TA 240 recorder. After occlusion of blood flow by the tourniquet in the upper arm, in which the neuromuscular monitoring was applied on the wrist, we administered the equipotent dose (ED95) of succinylcholine (S group), mivacurium (M group), and vecuronium (V group) intravenously on the contralateral arm respectively. We measured the maximal depression (%) of twitch height after the releasing tourniquet at 30, 60, 90, 120, 150, and 240 second intervals after the injection of each drug. RESULTS: The depression of twitch height was not found from 90 seconds of tourniquet time in the M group, and 120 seconds of tourniquet time in the S group. However, in the V group, the depression of twitch height was maintained to 240 seconds of tourniquet time. CONCLUSIONS: It is suggested that the plasma concentration of mivacurium declined faster than that of succinylcholine, and that of vecuronium decreased slowest among the groups after intravenous administration of equipotent dose (ED95).

The Effect of Frequency of Stimulation on Partial Twitch Depression in a Rat Phrenic Nerve Hemidiaphragm Preparation / 대한마취과학회지

Background: This study was designed to determine whether presynaptic receptor blockade could be differentiated from postsynaptic receptor blockade by examining the effect of increasing frequencies of indirect stimulation on partial twitch depression in vitro rat phrenic nerve hemidiaphragm preparations. Methods: After isolating rat phrenic nerve hemidiaphragm preparation, T200/T1 ratio (twitch height of the 200th stimuli divided by that of the 1st stimuli) at frequencies of 0.2, 0.5, 1.0, and 2.0 Hz using a drug concentration which provided approximately 20% twitch depression at 0.1 Hz was calculated. To compare T200/T1 ratios with TOF ratios, 2.0 Hz TOF response was measured immediately after 200th stimuli at either frequency of stimulation. Results: Hexamethonium caused a marked decrease in T200/T1 ratio at 0.5~2.0 Hz of stimulation, whereas alpha-bungarotoxin caused no change in T200/T1 ratios at up to 2.0 Hz of stimulation. The T200/T1 ratios produced by d-tubocurarine, vecuronium, mivacurium, and rocuronium located intermediate between alpha-bungarotoxin and hexamethonium, however significant differences among four drugs were found at 2.0 Hz. The propensity for decrease in T200/T1 ratios at 2.0 Hz might differ from this study: hexamethonium >d-tubocurarine >rocuronium >mivacurium = vecuronium >alpha-bungarotoxin. T200/T1 ratios at 2.0 Hz were not different from TOF ratios. Conclusions: When the observed effects in this study were provided with result of alpha-bungarotoxin acting predominantly at postsynaptic receptors and hexamethonium acting predominantly at presynaptic receptors, the effects of nondepolarizing muscle relaxants at each binding site could be differentiated by examining the T200/T1 ratios at 2.0 Hz.

Electrodiagnostic Evaluation of Myofascial Trigger Point

Since the myofascial trigger point(MFTrP) has been described fifty years ago, its underlying pathophysiology has been remained unclear. The diagnosis also depends on the characteristic pain, tenderness and physical findin gs, which is yery subjective. In recent years, some physicians investigated the objective findings of MFTrP, using the pressure algometer and thermography. We investigated the electromyographic findings of MFTrP to evaluate the clinical usefulness of local twitch response(LTR) and sympathetic skin response (SSR), and to evaluate the electrophysiologic characteristics of MFTrP. 21 patients, diagnosed as myofascial trigger point syndrome on upper trapezius and so on, were evaluated for the triggering pain with visual analog scale(VAS), pressure threshold(THpr) using pressure algometer(Dolorimeter), LTP with concentric needle electrode and SSR on the palm. There was a significant negative correlation between VAS and THpr, but no significant correlation with electromyographic findings of LTR. Thus LTR could support the existence of MFTrP electrodiagnostically, but, could not explain the clinically correlated severity of MFTrP. There were only 3 patients showing abnormal SSR, who were all complaining the sympathetic sympathetic symptoms on the affected arm with reffered pain. Even though referred pain to arm and hand existed. SSR was normal because suggested autonomic dysfunction of MFTrP is localized mechanism. Among the 13 patients underwent the trigger point block, 8 patients who showed no residual LTR immediate after MFTrP block, had a great symptomatic improvement of MFTrP in a week, but 5 patients who showed the residual LTR did not, Regardless of complaint of pain and soreness immediate after block, loss of LTR would be predicted as a good treatment result. In some cases, spontaneous EMG activity exist within the 3-4mm sized focus of MFTrP. although the taut band of MFTrP is 3-4cm length and depth. But this focus of MFTrP is a electrophysiologic changes within a muscle, not a structural changes seen by ultrasonography.

A Case of Anesthetic Management for Progressive Muscular Dystrophy / 대한마취과학회지

A 43 years old female patient who had known FSH form(Fascioscapulohumoral type) muscular dystrophy was scheduled for total abdominal hysterectomy due to uterine myoma. Induction of ansthesia was performed without muscle relaxant and maintained with fentanyl, oxygen and nitrous oxide. Muscle relaxation was excellent without neuromuscular blocking agent by the meuromuscular twitch monitoring(too week response to neuromuscular twitch at 70mA). After the end of operation, the patient was awaken without any problem and was transferred to recovery room.

A Case of Anesthetic Management for Progressive Muscular Dystrophy / 대한마취과학회지

A 43 years old female patient who had known FSH form(Fascioscapulohumoral type) muscular dystrophy was scheduled for total abdominal hysterectomy due to uterine myoma. Induction of ansthesia was performed without muscle relaxant and maintained with fentanyl, oxygen and nitrous oxide. Muscle relaxation was excellent without neuromuscular blocking agent by the meuromuscular twitch monitoring(too week response to neuromuscular twitch at 70mA). After the end of operation, the patient was awaken without any problem and was transferred to recovery room.