The neuromuscular effects of sevoflurane and isoflurane alone and in combination with vecuronium or atracurium in the rat

Sevoflurane was compared to isoflurane anesthesia alone and in combination with atracurium or vecuronium in 84 rats using the sciatic nerve—anterior tibialis muscle preparation. Both bolus injection and infusion rate techniques were used to evaluate these drug interactions. The ED₅₀ (dose which produced a 50% depression of twitch tension) of atracurium was 311 ± 31 and 360 ± 32µg·kg^–1 during 1.25MAC sevoflurane and isoflurane anesthesia respectively. The ED₅₀ of vecuronium was 190 ± 27 and 149 ± 14µg·kg^–1 during 1.25MAC sevoflurane and isoflurane anesthesia respectively. The mean infusion rates of atracurium and vecuronium required to maintain a 50% depression of twitch tension were 5.04 ± 0.7 and 2.02 ± 0.3mg·kg^–1·hr^–1. These infusion rates were 5.04 ± 0.7 and 2.02 ± 0.3mg·kg^–1·hr^–1 during 1.25MAC sevoflurane and 3.73 ± 0.3 and 1.81 ± 0.4mg·kg^–1·hr^–1 during 1.25MAC isoflurane anesthesia respectively. With both atracurium and vecuronium, the infusion rate required to maintain a 50% depression twitch of tension was inversely related to the concentrations of isoflurane and sevoflurane. The authors conclude that sevoflurane is similar in potency to that of isoflurane in augmenting a vecuronium or atracurium induced neuromuscular blockade in a dose-dependent manner.(Shin YS, Miller RD, Caldwell JE, et al.: The neuromuscular effects of sevoflurane and isoflurane alone and in combination with vecuronium or atracurium in the rat. J Anesth 6: 1–8, 1992)     

Practices surrounding syringe acquisition and disposal: effects of Syringe Exchange Programmes from different Brazilian regions—the AjUDE-Brasil II Project

The study describes practices relating to syringe acquisition and disposal by Syringe Exchange Programme (SEP) participants. A cross-sectional multi-city study enrolled 857 injection drug users (IDUs) from six SEPs in different Brazilian regions, and assessed self-reported acquisition and disposal behaviours. Seven hundred and nine males (82.9%) and 146 females (17.1%) were recruited through outreach and interviewed, most from the streets or their neighbourhoods (54.1%). The average age was 28.5 years; 76.4% reported injecting cocaine in the past 6 months. Sources for acquiring new syringes differed significantly between time of injection drug use debut and the 6 months prior to interview. Fifty-three percent of IDUs reported acquiring their syringes in pharmacies when they initiated injection drug use, whereas most reported acquiring new syringes in the 6 months before interview from several simultaneous sources: 69% through SEPs; 58% through pharmacies; 36% from friends and/or sexual partners; and 17% from other health services. Across SEPs, acquisition and disposal varied widely. Most interviewees discarded their syringes on the streets, in open fields, or in the garbage or sewage. Restrictions on syringe availability and unsafe practices may be functioning as barriers to the public health recommendation of one-time use of sterile syringes for IDUs and discouraging community support to SEPs. Further increase in access to legal, inexpensive and timely sterile syringes, as well as counselling about the merits of one-time use and safer disposal must be reinforced as part of efforts to minimise high-risk behaviours and curb the spread of blood-borne infections.     

高效液相色谱法-蒸发光散射检测器测定蒺藜中蒺藜新苷的含量

目的:建立蒺藜中蒺藜新苷的含量测定方法。方法:应用高效液相色谱法-蒸发光散射检测器,Supelco C18色谱柱(250mm×4.6mm,10μm),乙腈-甲醇-水(30:10:60)为流动相,流速为1.0 mL·min-1,Sedex蒸发光散射检测器参数:漂移管温度41℃,压力2.2×105 Pa。测定了蒺藜中蒺藜新苷的含量。结果:蒺藜新苷在3.988-13.96μg范围内有良好线性关系,r=0.9995(n=6)。蒺藜新苷的平均回收率为97.5％(n=6)。结论:该方法快速简便,灵敏、准确,可用于蒺藜药材中蒺藜新苷的含量测定。     

直肠癌术前CT分期与术后病理比较研究

目的探讨直肠癌术前CT分期与术后病理表现的关系.方法收集了经手术病理证实的直肠癌患者52例,分析其CT表现,并与术后病理结果对照.结果CT对侵犯深度判定的准确率达88.5%,对转移淋巴结判定的准确率达96%,能够很好显示病变范围、侵润程度、周围器官受侵及淋巴结转移情况.CT分期与病理分期基本相符.结论通过直肠癌的CT征象分析,对于术前推断肿瘤的恶性程度及患者的预后有重要价值.     

The Stiles-Crawford function of an albino observer

Stiles-Crawford functions (SCF's) were measured for both eyes of an albino observer with a marked pendular nystagmus using an eye position monitoring system. Both eyes demonstrated directional sensitivity as revealed by their SCF's. The directional sensitivity of both eyes was less than that of either the foveal or parafoveal region of normal observers. In addition, there was a significant difference between the SCF's for the albino observer's two eyes. Our results suggest that the psychophysical SCF is predominately the result of the orientational distribution of groups of receptors on the retina.