2.Effects of midazolam on the response of parafascicular nucleus to noxious stimuli
Chinese Journal of Anesthesiology 1994;0(01):-
Objective To investigate the effect of intravenous midazolam on the response of parafascicular nucleus(Pf) to noxious stimuli in rats. Methods Twenty SD rats of both sexes weighing 260-300g were used in the study. The animals were anesthetized with intraperitoneal urethane(1.2 g/kg) . A hole was drilled in the skull. Under stereomicroscope micro-glass electrode was inserted into Pf nucleus and the characteristic discharge of nociceptive neurons was recorded. The experiment was then performed in four steps. The discharge was recorded in the basal state (A), when hind paw was pinched by a pair of strong forceps: noxious stimuli (B) , 2 min after midazolam 0.2 mg/kg was given intravenously , step B was repeated (C) and flumazenil 0.05mg was given iv and 2 min later step B was repeated (D) . There was a pause of 5 min after each step. Results The characteristic discharge of nociceptive neurons was recorded only in 9 animals and the data from 6 animals were complete and could be analyzed. Noxious stimuli induced significant increase in spike of discharge of nociceptive neurons. Midazolam significantly depressed the response of nociceptive neurons to noxious stimuli. There was no significant difference in the mean spikes of discharge of nociceptive neurons between step A and C. After flumazenil the mean spike of discharge increased again in response to noxious stimuli. Conclusion Midazolam can inhibit the activity of the nociceptive neurons located in Pf nucleus, probably through GABA-BZ receptor.
3.The antinociceptive effect of fentanyl on the discharges of the neurons in the parafascicular nucleus evoked by coronary artery occlusion
Chinese Journal of Anesthesiology 1996;0(07):-
Objective The purpose of this study was to determine if parafascicular nucleus of thalamus is involved in the nociceptive stimulation evoked by coronary artery occlusion-induced acute myocardial ischemia and to investigate the effect of fentanyl on this nociceptive stimulation. Methods Male SD rats weighing 260-300 g were operated upon under general anesthesia with intraperitoneal urethane (1.2 g ? kg -1 ) and local infiltration of the skin incision. The discharges of pain-sensitive neurons (PSN) were recorded for 20 seconds every 5 min using single-barrel glass electrode before and after the coronary artery occlusion ( CAO) . The study was divided into 3 groups: group Ⅰ CAO alone ( n = 9); group Ⅱ CAO + fentanyl ( n = 6) : fentanyl 0.01 mg ?kg-1 was administered iv 15 min after CAO; group Ⅲ CAO + fentanyl + naloxone ( n = 6) : naloxone 0.04 mg? kg-1 was administered iv 15 min after intravenous fentanyl administration. Results The discharge frequency was significantly increased following CAO and peaked within 5-10 min after CAO and maintained for 60 min. The increased frequency of nociceptive discharge was significantly inhibited within 10 min after fentanyl and intravenous naloxone could completely antagonize the inhibitory effect of fentanyl. Conclusion Visceral pain can be evoked by acute myocardial ischemia induced by coronary artery occlusion. Thalamic parafascicular nucleus is involved in the perception of nociception in CNS. Opioid receptors play a critical role in the modulation of the nociception.
4.Effects of urapidil on discharges of pain-sensitive neurons in thalamic parafascicular nucleus evoked by coronary artery occlusion in rats
Chinese Journal of Anesthesiology 1996;0(09):-
Objective To investigate the changes in discharge rates of pain-sensitive neurons (PSN) in thalamic parafaseicular nucleus ( Pf) following coronary artery occlusion (CAO) and the effects of urapidil, a partial 5-HT agonist. Methods One-hundred male SD rats weighing 260-300 g were operated upon under urethane anesthesia and local infiltration of the skin incision. The animals were tracheotomized and mechanically ventilated. A hole was drilled in the skull until the brain was exposed. A single-barrel glass electrode was inserted, aiming at the PSN, the discharges of which were filtered, amplified and recorded. Chest was opened and heart was exposed. A tie was placed around the anterior descending branch of left coronary artery which can be occluded whenever needed. The study was divided into 3 groups : group I CAO alone; group II CAO + urapidil and group III CAO + urapidil + methysergide ( a potent serotonin antagonist). Urapidil 0.21 mg.kg-1 was given intravenously 15 min after CAO. Methysergide 0.1 mg.kg-1 was given iv 20 min after urapidil. Results Discharges of PSN were recorded in 45 animals out of the 100, and the recordings were complete for investigation in 31 animals. CAO evoked significant increase in the discharge frequency of PSN in 18/31 animals. After intravenous urapidil the increased frequency of nociceptive discharges was inhibited; however intravenous methysergide could partially antagonize the antinociceptive effect of urapidil. Conclusion The results indicate that (1 )the nociceptive response could be induced by CAO in rats; (2) Pf nucleus of thafamus is involved in the myocardial ischemia-induced nociceptive response of central nervous system; (3) serotonin plays a critical role in the modulation of the nociceptive signal of acute myocardial ischemia.
5.The protective effect of hemodilution on the lung against ischemia-reperfusion injury
Chinese Journal of Anesthesiology 1994;0(01):-
C. Conclusion Adequate hemodilution can attenuate the lung injury induced by I/R. The protective effect is better if hemodilution is performed before I/R.
10.Research and thinking on road traffic injury.
Acta Academiae Medicinae Sinicae 2007;29(4):455-458
The risk factors of traffic crash include drinking/drunk drive, accident proneness, fatigue driving, speeding, and poor vehicle quality. This article introduces the protection, emergency treatment, and basic scientific research of road traffic injury (RTI). As a public health issue, RTI is preventable, and personal factor is a key problem. It is important to establish an accurate and comprehensive RTI database, which may provide necessary information for the epidemiological research and crash prevention. The author also gives some suggestions on road traffic safety development in our country.
Accidents, Traffic
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prevention & control
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Databases, Factual
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Epidemiologic Research Design
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Humans
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Wounds and Injuries
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prevention & control
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therapy