ABSTRACT
Objective To determine the dose-response relationship of anhydrous alcohol for thorac-ic sympathetic block in treating primary palmar hyperhidrosis. Methods Two hundred patients with prima-ry palmar hyperhidrosis, aged 18-33 yr, grade of palmar sweating 3 or 4, scheduled for elective surgery under thoracic sympathetic block, were divided into 5 different mixture of anhydrous alcohol and iohexol (iohexol : anhydrous alcohol=1 : 5)groups(n=40 each)using a random number table. Under CT guid-ance, thoracic intervertebral puncture was performed between T3and T4until the needle tip reached the spot around T4and above capitis costae. The mixture of anhydrous alcohol 10 ml(group R1), 15 ml(group R2), 20 ml(group R3), 25 ml(group R4)and 30 ml(group R5)and iohexol was injected into the thoracic sympathetic ganglia on both sides. Effective block was defined as the rise in the palm tempera-ture of both hands more than 3℃ and sweating completely disappeared at 10 min after thoracic sympathetic block was performed with anhydrous alcohol. The median effective dose(ED50), ED95and 95% confi-dence interval(CI)of anhydrous alcohol for thoracic sympathetic block in treating primary palmar hyper-hidrosis were calculated by probit analysis. Results The ED50(95% CI)of anhydrous alcohol for thorac-ic sympathetic block in treating primary palmar hyperhidrosis was 1882(1564-2201)ml, and the ED95 (95% CI)was 2806(2420-3812)ml. Conclusion The ED50and ED95of anhydrous alcohol for tho-racic sympathetic block in treating primary palmar hyperhidrosis are 1882 and 2806 ml, respectively.
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BACKGROUND: The aim of this review was to estimate the lethal and exposure doses of a representative symptom (blindness) of methanol exposure in humans by reviewing data from previous articles. METHODS: Available articles published from 1970 to 2016 that investigated the dose-response relationship for methanol exposure (i.e., the exposure concentration and the biological markers/clinical symptoms) were evaluated; the MEDLINE and RISS (Korean search engine) databases were searched. The available data from these articles were carefully selected to estimate the range and median of a lethal human dose. The regression equation and correlation coefficient (between the exposure level and urinary methanol concentration as a biological exposure marker) were assumed from the previous data. RESULTS: The lethal human dose of pure methanol was estimated at 15.8–474 g/person as a range and as 56.2 g/person as the median. The dose-response relationship between methanol vapor in ambient air and urinary methanol concentrations was thought to be correlated. An oral intake of 3.16–11.85 g/person of pure methanol could cause blindness. The lethal dose from respiratory intake was reported to be 4000–13,000 mg/l. The initial concentration of optic neuritis and blindness were shown to be 228.5 and 1103 mg/l, respectively, for a 12-h exposure. CONCLUSION: The concentration of biological exposure indices and clinical symptoms for methanol exposure might have a dose-response relationship according to previous articles. Even a low dose of pure methanol through oral or respiratory exposure might be lethal or result in blindness as a clinical symptom.
Subject(s)
Humans , Blindness , Methanol , Optic NeuritisABSTRACT
Objective To determine the optimum dose of dexmedetomidine administered locally through evaluating the effects of different doses of dexmedetomidine on the median effective concentration (EC50) of ropivacaine for brachial plexus block.Methods American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes, aged 19-50 yr, weighing 50-80 kg, scheduled for elective ulna and radius fracture open reduction and internal fixation, requiring ultrasound-guided axillary brachial plexus block, were randomly assigned into 4 groups using a random number table: control group (group C) and dexmedetomidine 0.4, 0.6 and 0.8 μg/kg groups (D1 , D2 and D3 groups).Axillary brachial plexus block was performed only with ropivacaine in group C.In D1-3 groups, axillary brachial plexus block was performed with the mixture of ropivacaine and dexmedetomidine 0.4, 0.6 and 0.8 μg/kg, respectively.The effective block was defined as complete loss of pain sensation in the areas innervated by the brachial plexus.The volume of local anesthetics was 40 ml.The concentration of ropivacaine was determined by up-and-down technique.The initial concentration was 0.4％ and the ratio between the two successive concentrations was 1.0.If the block was effective, the next patient received a lower dose of ropivacaine;or conversely if ineffective, a higher dose was given in the next patient.At least 7 independent crossover pairs were observed in each group.The EC50 of ropivacaine was the mean of the concentration of ropivacaine of each crossover pair.The occurrence of brachial plexus block-related adverse events, adverse cardiovascular events and over-sedation was recorded.Results In C, D1, D2 and D3 groups, 20, 22, 24 and 19 patientswere enrolled, respectively.Compared with group C, the EC50 of ropivacaine was significantly decreased in D2 and D3 groups, and no significant change in the EC50 of ropivacaine was found in group D1.No patients developed adverse events in group D1.The incidence of bradycardia was 17％, but it was transient in group D2.In group D3, the incidence of bradycardia and hypotension was 58％ and 32％, respectively, and they required special treatment, and the incidence of over-sedation was 10％.Conclusion The optimum dose of dexmedetomidine is 0.6 μg/kg when mixed with ropivacaine for brachial plexus block.
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This study was aimed to investigate the dose-response relations and synergy effects of bioactive components in Ginkgo bilobaon antiplatelet aggregation and DPPH free radical scavenging.The antiplatelet aggregation experiment and DPPH free radical scavenging experiment were conducted respectively to investigate the dose-response relations and synergy effects.Firstly,the effect of inhibiting platelet aggregation induced by PAF of ginkgolides in rabbits was investigated.And then,the effect of DPPH free radical scavenging by ginkgo flavonoids was also investigated.Finally,the synergy effects among effective components were studied.The results showed that ginkgolide A,ginkgolide B,ginkgolide C and bilobalide had dose-response relations on antiplatelet aggregation.Quercetin,kaempferol and isorhamnetin had DPPH free radical scavenging effects with dose-response relation.It was concluded that ginkgolide had the dose-response relation on antiplatelet aggregation.Ginkgolide A and ginkgolide B had synergy effect.Ginkgo flavonoids had DPPH free radical scavenging effect.Quercetin and isorhamnetin had synergy effect.
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Objective: To evaluate the effects of sevoflurane on the dose-response relationship and on the timecourse of recovery of rocuronium. Method: Sixty patients,ASA grade Ⅰ,aged 18 to 52 years, undergoing elective plastic surgery,were included in this study. Patients were equally allocated randomly to either the control or the sevoflurane group. Anesthesia was maintained with 60％ N_2O-O_2-thiopental in the control group,and with 1 MAC sevofurane-N_2O-O_2 in the sevoflurane group. The dose-response relationship of rocuronium was established with a cumulative dosing regimen. Result: The dose response curve of rocuronium in the sevoflurane group was shifted to the left. The ED_(50),ED_(90) and ED_95 of rocuronium were decreased by 31％, 27％ and 25％, respectively in sevoflurane group as compared with those of the control group. Following an intravenous administration of rocuronium 400ug/kg,the duration of peak effect,duration of clinical relaxation,recovery index,and the total duration of action in the sevoflurane group were significantly prolonged vs. the control group. Conclusion: Sevoflurane can significantly enhance the neuromuscular blockade effect of rocuronium and prolong its duration of action.
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Intravitreal fibrin clots were produced by intravitreal injection of 0.2 ml of autologous plasma in 62 rabbit eyes. The intravitreal injection of 0.25 micrograms or more of tissue plasminogen activator(tPA) resulted in a total clearing of intravitreal fibrin within one day in all treated eyes. This was significantly faster than in the control eyes, in which complete clearing was not seen until 8 days later. This represents the plateau on the dose-response curve in doses ranging from 0.25 to 200 micrograms. With light microscopy and transmission electron microscopy, retinal toxicity was demonstrated in eyes enucleated seven days after injection of 25 micrograms or more of tPA. This study demonstrates that tPA was effective and safe at 12.5 micrograms or less in clearing intravitreal fibrin in an experimental model. These results suggest that low dosages of tPA, probably of 3 micrograms or less, may be useful in the treatment of severe postvitrectomy fibrin formation seen clinically.