Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: FUNCTIONS OF ANGIOTENSIN PEPTIDES IN THE ROSTRAL VENTROLATERAL MEDULLA

• 1 It was first shown several years ago that the rostral part of the ventrolateral medulla (VLM) contains a high density of receptor binding sites for angiotensin II (AngII). In the present paper we briefly review recent studies aimed at determining the actions of both exogenous and endogenous angiotensin peptides in the rostral VLM, as well as their specific sites of action.
• 2 The results of these studies have shown that angiotensin peptides can excite pressor and sympathoexcitatory neurons in the rostral VLM, but do not appear to affect non-cardiovascular neurons in this region.
• 3 It is known that pressor neurons in the rostral VLM include both catecholamine and non-catecholamine neurons. There is evidence that, at least in conscious rabbits, both of these types of neurons are activated by AngII. The specific endogenous angiotensin peptide or peptides that affect pressor neurons in the rostral VLM have not yet been definitively identified.
• 4 It is also possible that different angiotensin peptides may have different effects on pressor neurons in the rostral VLM, mediated by different receptors. Further studies will be needed to define these different functions as well as the specific receptors and cellular mechanisms that subserve them.

     

The use of a safety factor in setting health based permissible levels for occupational exposure

Summary When adequate human observations are not or scarcely available, permissible levels for occupational exposure have to be extrapolated from animal experiments. Taking into account experimental conditions, e. g., duration of exposure ( 3 months), animal species, knowledge of no- (adverse-) effect level or minim al-(adverse-) level, presence of data on human observations, the authors worked out a procedure for extrapolation. This procedure should only be applied for systemic non-carcinogenic effects. The proposed procedure is to be regarded as tentative and as suggestion for international discussion.The evaluation starts with a safety factor = 10 for extrapolation from dose/kg b. w. in long-term animal experiments to exposure of adult workers (40 h/wk); this factor corresponds to a safety factor = 3–10 for extrapolation from doses presented as concentrations in air. If long-term experimental exposure is 24 h daily, the safety factor can be lowered to the minimum value of 1. If only short-term exposure studies are available, the safety factor may have to be increased to a maximum of 400.     

New non-cocaine-containing topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration /= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children.     

再发性低血糖对幼鼠脑内GLUT1及GLUT3表达的影响

目的观察再发性低血糖后脑内葡萄糖转运蛋白1(glucose transporter 1,GLUT1)及葡萄糖转运蛋白3(GLUT3)表达的变化,从而探讨无症状低血糖的发生机制。方法将80只15日龄野生型小鼠随机分为正常对照组及低血糖组,每组40只。低血糖组给予正规胰岛素腹腔注射3次,每次剂量为5U/kg,对照组注射等体积生理盐水。两组分别在最后1次注射后12、24、48及72 h处死小鼠取脑组织(每组每时间点10只),应用免疫组化方法观察小鼠脑内GLUT1及GLUT3表达的变化。结果低血糖后脑内微血管上GLUT1表达有增加趋势,皮质增加高于海马,72 h皮质GLUT1表达显著高于对照组;低血糖后48、72 h皮质及海马GLUT3表达均显著高于相应对照组。结论再发性低血糖后脑内GLUT1及GLUT3适应性增高,这种适应既能节省神经元的能量代谢,但也能削减神经元对低血糖的反应。     

糖肾胶囊对代谢综合征大鼠模型的影响

目的:对照研究糖肾胶囊对代谢综合征大鼠模型的影响。方法:高脂饲料诱导代谢综合征模型,随机将大鼠分为正常对照组、代谢综合征组、文迪雅组、糖肾胶囊组;用正常血糖高胰岛素钳夹技术评价胰岛素抵抗,尾部加压法测量血压,称取体质量和右侧附睾旁脂肪组织湿质量,生化法检测血脂4项,放免法测空腹胰岛素。结果:糖肾胶囊组较代谢综合征组胰岛素敏感性指数(M值)明显升高,血清甘油三酯(TG)水平明显降低,体质量、内脏脂肪和血清胰岛素水平有降低趋势。结论:糖肾胶囊能改善代谢综合征大鼠模型的胰岛素抵抗和高胰岛素血症,同时改善了大鼠脂质代谢。     

同种异体大鼠小肠移植中监测CD4+ T细胞和CD8+ T细胞数比值的意义

目的 探讨CD4+T细胞数/CD8+T细胞数作为大鼠同种异体小肠移植急性免疫排斥反应指标的可行性.方法 选取健康雄性成年SD、Wistar大鼠建立同种异体小肠移植模型,于大鼠术前和术后1、3、5、7、9d共6个时间段静脉取血,应用免疫荧光染色技术及流式细胞仪检测CD4+T细胞和CD8+T细胞百分率,并计算其比值.同期取移植小肠标本做组织学检测.结果 术后CD4+T细胞数和CD8+T细胞数比值前期增高后期降低.组织病理学检测发现术后小肠移植物的排斥反应由轻到重,术后第5天始CD4+T细胞数和CD8+T细胞数比值与急性免疫排斥反应程度呈正相关.结论 CD4+T细胞和CD8+T细胞数比值作为大鼠同种异体小肠移植术后急性免疫排斥反应的监测指标的可行性较大.     

兰索拉唑与莫沙必利联合治疗反流性食管炎的临床观察

目的 观察兰索拉唑与莫沙必利联合治疗反流性食管炎的临床效果.方法 89例反流性食管炎患者随机分为两组,治疗组50例用兰索拉唑和莫沙必利,对照组39例用盐酸雷尼替丁胶囊,观察治疗前及治疗后4、8周的临床症状改善情况和内镜变化.结果 用药4周时,治疗组反酸、恶心及胸骨后疼痛治疗有效率分别为78%、84%、82%,与对照组比较差异有统计学意义(P＜0.05).用药8周结束时,治疗组反酸、恶心及胸骨后疼痛全部改善,总有效率分别是98%、98%和93%,明显优于对照组的64%、81%和73%(均P＜0.05);内镜4周、8周复查治疗组与对照组食管黏膜病损愈合率分别为84%和62%,96%和77%,差异有统计学意义(P＜0.05).结论 兰索拉唑、莫沙必利联合用药是治疗反流性食管炎安全、有效的方法.     

复方土牛膝糖浆剂抗病毒作用的实验研究

目的:观察复方土牛膝糖浆剂在体外和动物模型上的抗病毒作用。方法:用细胞培养法,通过观察细胞病变评价复方土牛膝糖浆剂对常见的致上呼吸道感染的柯萨奇B族病毒4型(CoxB4)、副流感病毒(HVJ)、呼吸道合胞病毒(RSV)、单纯疱疹病毒(HSV-Ⅰ)所致的细胞病变(CPE)的抑制作用;通过用流感病毒滴鼻感染小鼠来研究复方土牛膝糖浆剂对病毒感染小鼠所引起的死亡保护作用。结果:复方土牛膝糖浆在体外对CoxB4、RSV病毒的致细胞病变作用有明显抑制作用,其IC50分别为2.0、2.8μL糖浆/mL,TI分别为5.6和4,对HSV-1、副流感-1型病毒的致细胞病变有一定的抑制作用。其IC50分别为4.0、5.0μL糖浆/mL,TI分别为2.8和2.24。在小鼠感染病毒15天内,复方土牛膝糖浆5mL/(kg.d)剂量组动物的死亡率为55%;死亡保护率分别为38.39%,与感染对照组相比有显著差异(P<0.05),复方土牛膝糖浆10mL/(kg.d)、5mL/(kg.d)两个剂量组小鼠的存活天数较感染组明显延长,与对照组比较有显著性差异。生命延长率分别为17.67%和22.22%。结论:复方土牛膝糖浆剂无论在体内或是体外均有较明显的抗病毒作用。     

四川若尔盖产麻花艽药材HPLC指纹图谱研究

目的建立四川若尔盖地区产麻花艽Gentiana straminea Maxim.药材HPLC指纹图谱。方法以龙胆苦苷为内参照物,分析10批麻花艽药材的HPLC色谱行为,同时以当地产近缘种黄管秦艽Gentiana officinalisH.Smith及国家药典品种粗茎秦艽Gentiana crassicaulis Duthie ex Burk.为外类群进行比对。色谱条件：UltimateXB-C18（250 mm×4.6 mm,5μm）;流动相：乙腈-0.02%乙酸水梯度洗脱;体积流量：1 mL/min;检测波长：240 nm;柱温：30℃;进样量：10μL。结果标定16个共有峰,确定其中2个峰的归属,建立了可与上述2个外类群相区别的麻花艽指纹图谱。结论该图谱基本反映了四川若尔盖地区产麻花艽化学背景特征,可为道地药材评价及相关中藏药品种鉴定提供基础资料。     

龙葵药材薄层鉴别研究

目的研究中药龙葵的薄层鉴别方法。方法依据现行《中国药典》2010年版一部附录ⅥB试验方法考察了不同提取方法、薄层板、展开剂、显色剂下龙葵的薄层鉴别方法。结果用硅胶G薄层板．二氯甲烷一甲醇一氨水（8：1．5：0．4）为展开剂,以10％硫酸乙醇试液显色,再置紫外灯（365nm）下检视斑点,分离效果最佳。结论本实验研究可作为龙葵药材质量标准的修订内容。