异丙酚早期给药对内毒素休克大鼠急性肺损伤的保护作用

目的观察不同时点给予异丙酚对脂多糖(LPS)致内毒素休克大鼠急性肺损伤(ALI)的保护作用及机制.方法静脉注射LPS 8 mg·kg-1复制内毒素致ALI模型,雄性Wistar大鼠76只随机分为5组对照组(A组,n=8)、LPS组(B组,n=17)、异丙酚给药组(C～E组,n=17),C组、D组和E组分别于LPS注入前1 h、LPS注入即刻、LPS注入后1 h、静脉注射异丙酚5 mg·kg-1,继以10mg·kg-1·h-1持续泵注.从注入LPS至实验结束,历时5 h.持续监测平均动脉压(MAP),测定支气管肺泡灌洗液(BALF)中蛋白(BALFpro)、一氧化氮(NO)、肿瘤坏死因子(TNF-α)、肺组织湿/干重比、肺通透指数(PPI)、肺组织中硝基酪氨酸(NT)表达、NT的Westem Blot、肺组织中诱生型一氧化氮合酶mRNA表达及大鼠死亡率.结果与基础值比较,B组、C组、D组、E组在注入LPS后3、5 h MAP降低(P＜0.05),与B组比较,C组、D组注入LPS后5 h MAP降低(P＜0.05).与A组比较,B组、D组、E组PPI、W/D、BALFpro及BALF中TNF-α、NO均升高(P＜0.01),C组W/D、BALFpro及BALF中TNF-α、NO升高(P＜0.01);与B组比较,C组、D组PPI、W/D、BALFpro及BALF中TNF-α、NO均降低(P＜0.05或0.01),E组W/D、BALFpro及BALF中NO降低(P＜0.05).与B组比较,A组NT微弱表达,B组表达明显增强,C组、D组、E组表达减弱,以C组最明显.与B组比较,C组、D组、E组吸光度比值降低(P＜0.01).A组、B组、C组、D组、E组大鼠死亡率分别为0%、64.7%、11.8%、23.5%和41.2%.结论异丙酚早期给药对内毒素致ALI有保护作用.     

异丙酚、氯胺酮对哮喘大鼠气道痉挛及气道渗出的作用

目的 观察异丙酚、氯胺酮对抗原诱发哮喘大鼠气道痉挛及气道渗出的影响。方法哮喘大鼠30只随机分为5组:I组,静注生理盐水;Ⅱ组,静注异丙酚50 mg·kg·-1·h-1;Ⅲ组,静注异丙酚100 mg·kg-1·h-1;Ⅳ组,静注氯胺酮50 mg·kg-1·h-1;V组,静注氯胺酮100 mg·kg-1·h-1。30 min后静注伊文氏蓝;5 min后静注卵蛋白激发哮喘发作,并维持30 min。观察气道压、肺系数、肺湿干重比、肺含水量、肺组织伊文氏蓝含量变化。结果异丙酚和氯胺酮能显著缓解卵蛋白激发引起的气道痉挛反应(P<0.05),相同剂量异丙酚和氯胺酮对气道压的影响无显著性差异。异丙酚和氯胺酮均可明显降低大鼠肺系数、肺湿干重比和肺含水量(P<0.05)。静注异丙酚或氯胺酮后,肺组织伊文氏蓝渗出明显减少,与I组比较差异有显著性(P<0.05)。结论 异丙酚和氯胺酮均能缓解抗原诱发哮喘大鼠的气道痉挛,且能明显抑制哮喘大鼠的气道渗出。     

不同剂量异丙酚对大鼠小肠缺血再灌注后肺损伤超微结构的影响

目的 探讨不同临床剂量异丙酚对大鼠小肠缺血再灌注后肺损伤肺组织钙离子含量变化和肺组织超微结构改变的影响及其保护作用。方法 雄性SD大鼠40只,随机分为假手术对照组(Ⅰ组)。小肠缺血再灌注组(Ⅱ组)及分别给予异丙酚4mg·kg-1·h-1、8mg·kg-1·h-1、10mg·kg-1·h-1(Ⅳ、Ⅳ、Ⅴ)5组;制作小肠缺血再灌注模型。实验结束即刻取部分肺组织固定于2.5％戊二醛行透射电镜检查肺组织超微结构,部分肺组织用原子吸收分光光度法测钙离子含量。结果IIR后Ⅱ组、Ⅲ组肺组织钙离子含量明显升高,与Ⅰ组、Ⅳ组、Ⅴ组相比均有非常显著差异(P<0.01),Ⅳ组、Ⅴ组与Ⅰ组相比无统计学差异,同时Ⅱ组、Ⅲ组肺组织钙离子含量相比显著差异(P<0.05)。Ⅱ组肺组织超微结构明显受损,异丙酚用药组肺组织超微结构均明显改善,尤其Ⅳ组、Ⅴ组两组除线粒体结构轻微改变外基本接近正常。结论 钙离子在大鼠小肠缺血再灌注后肺损伤中有重要作用,临床剂量异丙酚可明显降低肺组织钙离子含量,并对肺组织超微结构产生保护作用。     

异丙酚对大鼠油酸性急性肺损伤的保护作用

目的观察异丙酚对大鼠油酸性急性肺损伤(ALI)的保护作用及其机制。方法 40只成年雄性 SD 大鼠,体重：250～290g,随机分成5组：正常对照组(Ⅰ组)、ALI 组(Ⅱ组)、4mg·kg~(-1)·h~(-1) 异丙酚治疗组(Ⅲ组)、8mg·kg~(-1)·h~(-1)异丙酚治疗组(Ⅳ组)、16mg·kg~(-1)·h~(-1)异丙酚治疗组(Ⅴ组)；Ⅱ～Ⅴ组静脉注射油酸250μl·kg~(-1)制备大鼠 ALI 模型,然后Ⅲ～Ⅴ组持续静脉输注异丙酚4h 时处死大鼠。测定肺组织 MDA 含量及 MPO、SOD 活性；透射电镜观察肺组织超微结构变化；免疫组化及流式细胞术测定肺组织白介素(IL)-18、IL-10水平；电泳迁移率变动分析技术测定肺组织 NF-(?)B 的表达。结果电镜显示Ⅱ组肺泡Ⅱ型上皮细胞线粒体、粗面内质网及嗜锇性板层小体损伤；Ⅲ～Ⅴ组肺泡Ⅱ型上皮细胞细胞器损伤均有不同程度改善,尤以Ⅳ组效果明显。与Ⅰ组比较,Ⅱ组肺组织 MDA、IL-10、 IL-18、NF-(?)B 水平升高,MPO、SOD 活性降低(P＜0.05)；静脉输注异丙酚使 ALI 大鼠肺组织 MPO、SOD 活性升高,MDA、IL-18、NF-(?)B 水平降低,IL-10水平升高(P＜0.05)。结论 4～16mg·kg~(-1)·h~(-1)异丙酚均可抑制油酸性 ALI 时的氧化应激反应,阻断 NF-(?)B 的活化,减轻肺部炎性反应,对油酸性 ALI 起到一定的保护作用,8mg·kg~(-1)·h~(-1)剂量效果较好。     

异丙酚对大鼠肠缺血再灌注后肺损伤的影响

目的探讨异丙酚对大鼠肠缺血再灌注后肺损伤的影响。方法32只成年SD大鼠,随机分为4组（n=8）,缺血再灌注组（I/R组）缺血1 h,再灌注2 h;异丙酚1组（P1组）在缺血前10 min、异丙酚2组（P2组）在再灌注前10min静脉注射异丙酚10mg,kg,然后以10mg·kg^-1·h^-1持续输注,余处理同I/R组;假手术组（C组）不行缺血再灌注及异丙酚输注。所有大鼠在再灌注120 min时处死。光镜下观察肺组织形态学及细胞凋亡;测定肺组织超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量及含水量。结果I/R组光镜下可见大量肺泡塌陷、实变,肺实质水肿及中性粒细胞浸润聚集。与C组比较,I/R组及P2组肺组织细胞凋亡计数增加,I/R组肺组织SOD活性降低,MDA含量升高,含水量升高（P＜0．05或0．01）;与I/R组比较,P1组SOD活性升高,MDA含量降低（P＜0．01）。结论细胞凋亡参与了大鼠肠缺血再灌注后肺损伤的发生,肠缺血前给予异丙酚可明显减轻肠缺血再灌注后肺损伤。     

异丙酚对肺缺血再灌注损伤大鼠肺上皮细胞凋亡的影响

目的拟通过观察肺上皮细胞凋亡的变化,探讨异丙酚减轻大鼠肺缺血再灌注损伤的作用机制。方法雄性SD大鼠136只,随机分为3组:假手术组(S组,n=24)、缺血再灌注组(I/R组,n=56)、异丙酚组(P组,n=56)。I/R组、P组制备大鼠肺原位热缺血模型,缺血1h。P组于缺血前30min静脉输注异丙酚20mg·kg~(-1)·h~(-1)至再灌注4h。S组除不作缺血处理外,其余处理与I/R组相同。分别于再灌注0.5、1、2、4h随机处死大鼠(S组每个时点处死6只,I/R组、P组每个时点分别处死14只大鼠),每组每个时点的一半大鼠用于测定支气管肺泡灌洗液(BALF)中中性粒细胞百分比、蛋白浓度,另外一半大鼠用于测定肺组织丙二醛(MDA)含量、湿,干重比(W/D)及肺上皮细胞凋亡指数(TUNEL法),并在光镜下观察肺组织的病理学改变;I/R组、P组肺上皮细胞凋亡指数与W/D进行直线相关分析。结果与S组相比,I/R组和P组再灌注各时点BALF中中性粒细胞百分比、蛋白浓度及肺组织MDA含量、W/D、肺上皮细胞凋亡指数均增加(P<0.05或0.01);与I/R组比较,P组上述指标均降低(P<0.05或0.01),肺组织病理学损伤减轻;I/R组、P组肺上皮细胞凋亡指数与W/D之间的相关系数分别为0.784、0.830(P<0.01)。结论异丙酚抑制肺上皮细胞凋亡可能是减轻大鼠肺缺血再灌注损伤的机制之一。     

持续静脉输注ATP对腹部手术患者靶控输注异丙酚效应室浓度的影响

目的探讨腹部手术患者麻醉中持续静脉输注ATP对靶控输注异丙酚效应室浓度的影响。方法择期下腹部手术患者60例,ASAⅠ级或Ⅱ级,年龄44～64岁,体重49～87kg,随机分为3组（n=20）：异丙酚组（P组）单纯靶控输注异丙酚维持麻醉;ATP1组和ARP2,组在靶控输注异丙酚的同时,分别以微量泵持续静脉输注ATP 0．4 mg·kg^-1·h^-1和0．6mg·kg^-1·h^-1。术中根据BIS、MAP、HR调整异丙酚血浆靶浓度。当BIS＞55或BIS＜40时则以0．2μg/ml幅度增加或降低异丙酚靶浓度。术中静脉输注芬太尼,并根据需要使用血管活性药物。于麻醉诱导前即刻（T0）、气管插管前即刻（T1）、气管插管后即刻（T2）、切皮前即刻（T3）、切皮后10 min（T4）和60 min（L5）、术毕（T5）、呼之睁眼（L7）以及气管拔管后即刻（L8）记录HR、MAP、SpO2、BIS。记录麻醉全程异丙酚效应室浓度及停止靶控输注后TCI泵所显示的效应室浓度。结果3组一般资料、麻醉时间、芬太尼用量及苏醒时间比较差异无统计学意义（P＞0．05）。3组MAP、HR及SpO2维持在正常范围。术中异丙酚效应室浓度：与P组比较, ATP1组在T4至T8时降低,ATP2组在T1至T8时降低（p＜0．05或0．01）;与ATP1组比较,ATP2组T5至T7时降低（P＜0．05）。结论腹部手术患者麻醉中,BIS维持40～55时,ATP 0．4～0．6 mg·kg^-1·h^-1持续静脉输注可降低靶控输注异丙酚效应室浓度,且随ATP用药量的增加,异丙酚用药量相应减少,且不影响苏醒时间。     

异丙酚减轻大鼠机械通气所致肺损伤

目的探讨异丙酚对大鼠高压力机械通气所致急性肺损伤的影响。方法24只Wistar大鼠随机分为3组（n=8）,采用压力控制机械通气模式通气。A组为对照组,通气模式为PIP=25 cmH2O,PEEP=2 cm H2O;B、C两组为异丙酚组,通气模式同A组,B组输注模式为静注2 mg／kg,继以4 mg·ks^-1·h^-1速度持续输注;C组输注模式为静注5 mg／kg,继以10 mg·kg^-1·h^-1速度持续输注,记录基础时点、1h、2 h、3 h、4 h的MAP、HR和动脉血气。4 h后处死全部大鼠。测量肺组织湿干比、BALF中蛋白含量,观察肺组织病理形态学变化。结果A组MAP、PaO2和pH在4 h时显著降低,与基础值相比有统计学差异（P〈 0．05）,而B、C两组与基础值相比无明显变化。在4h时A组的PaCO2显著升高（P〈0．05）,而B、C两组与基础值相比无明显变化。肺组织湿／干比和BALF中蛋白含量A组亦明显高于B、C两组（P〈0．05）。B、C组间无显著差别。肺组织形态学改变B、C组好于A组,肺组织中性粒细胞浸润程度也较轻。结论异丙酚对机械通气所致急性肺损伤具有保护作用,其机制可能与减少中性粒细胞在肺内浸润有关。     

戊乙奎醚对肢体缺血再灌注诱发大鼠肺损伤的影响

目的 探讨戊乙奎醚对肢体缺血再灌注诱发大鼠肺损伤的影响.方法 雄性Wistar大鼠36只,体重250～300 g,随机分为4组(n=9):对照组(Ⅰ组)、肢体缺血再灌注诱发肺损伤组(Ⅱ组)、小剂量盐酸戊乙奎醚组(Ⅲ组)和大剂量盐酸戊乙奎醚组(Ⅳ组).Ⅱ组、Ⅲ组和Ⅳ组麻醉后双后肢缺血3 h,Ⅲ组和Ⅳ组分别于股动脉开放前10 min肌肉注射盐酸戊乙奎醚2、9 mg/kg,再灌注4 h快速取肺,计算肺组织湿/干重比(W/D),透射电镜下观察肺组织超微结构,酶联免疫吸附法测定肺组织肿瘤坏死因子-α(TNF-α)和白细胞介素(IL)-10含量.结果 与Ⅰ组比较,Ⅱ组肺组织W/D及TNF-α、IL-10含量升高(P<0.01);与Ⅱ组比较,Ⅲ组肺组织W/D及TNDF-α含量降低、IL-10含量升高(P<0.01);与Ⅲ组比较,Ⅳ组肺组织W/D及TNF-α含量降低、IL-10含量升高(P<0.01).结论 戊乙奎醚可减轻肢体缺血再灌注诱发大鼠肺损伤,且呈剂量依赖性,其机制与降低肺组织炎性反应有关.     

不同程度呼吸机相关性肺损伤大鼠血清CC10蛋白水平的比较

目的 比较不同程度呼吸机相关性肺损伤(VILI)大鼠血清CCIO蛋白的水平.方法 清洁级Wistar大鼠40只,雌雄不拘,体重200～250 g,随机分为5组(n=8),对照组(Ⅰ组)仅切开气管,不行机械通气;轻度肺损伤组(Ⅱ组)潮气量(VT)7 ml/kg,机械通气2 h;中度肺损伤组(Ⅲ组)VT 7 ml/kg,机械通气4 h;重度肺损伤组(Ⅳ组)VT 40 ml/kg,机械通气2 h;极重度肺损伤组(Ⅴ组)VT 40 ml/kg,机械通气4 h.Ⅰ组在气管切开后即刻,其余各组在机械通气结束时采集腹主动脉血3 ml,并收集支气管肺泡灌洗液(BALF),测定血清和BALF中CC10蛋白水平;观察肺Clara细胞;计算肺湿/干重比(W/D).结果 Ⅳ组和Ⅴ组终末细支气管、呼吸细支气管管腔有大量脱落Clara细胞,血管壁有大量漏出的CC10蛋白,其余组上述表现不明显;Ⅱ组～Ⅴ组血清CC10蛋白水平逐渐升高,肺组织损伤程度逐渐加重(P＜0.05);与Ⅰ组、Ⅱ组和Ⅲ组比较,Ⅳ组和Ⅴ组BALF中CC10蛋白水平降低(P＜0.05);血清CC10蛋白水平与肺组织损伤程度和肺W/D呈正相关,相关系数分别为0.915和0.846(P＜0.01);BALF中CC10蛋白水平与肺组织损伤程度和肺W/D呈负相关,相关系数分别为-0.799和-0.816(P＜0.01).结论 血清CC10蛋白水平与大鼠呼吸机相关性肺损伤程度有关.     

Histochemical and contractile properties of striated muscles of urethra and levator ani of dogs and sheep

AIMS: To understand their possible importance in long- and short-term control of continence, some properties of the striated muscles of the urethra and pelvic floor (levator ani) of dogs and sheep were investigated, especially fiber types and contractile characteristics. MATERIALS AND METHODS: Striated muscles of urethra and levator ani of 29 male and 6 female dogs and 11 male and 6 female sheep were removed and cut into strips. Some strips were frozen and stained for ATPase at pH 9.4 and 4.3 for fiber typing; others were set up in an organ bath to study contractile responses to nerve stimulation. RESULTS: All muscles contained both type I (slow) and type II fibers, ranging from 97% type II in female greyhound urethra to 60% in female sheep levator ani. For each muscle, there were fewer type II muscles in sheep than in dog. The diameters of the urethral fibers were about 60% of the levator ani in dogs and 34% in sheep. Contraction of the urethral muscle was faster than for levator ani and declined to about 80% of the peak, 500 msec after the beginning of stimulation at 20 Hz. The levator ani contraction rose to a steady level as long as stimulation continued. CONCLUSIONS: Both the levator ani and urethral striated muscles contain slow and fast fiber types. The levator ani muscles are capable of sustained contraction with rapid onset which will produce long-term closure of the urethra. The circular urethral muscle contraction was faster but less well maintained.     

Recognition and management of phaeochromocytoma and paraganglioma

Phaeochromocytomas and paragangliomas (PPGL) are catecholamine-secreting neuroendocrine tumours arising from the chromaffin cells in the adrenal medulla. These tumours may be identified incidentally, as part of a work-up for multiple endocrine neoplasia or following haemodynamic surges during unrelated procedures. Advances in perioperative management and improved management of intraoperative haemodynamic instability have significantly reduced surgical mortality from around 40% to less than 3%. Surgery is the definitive treatment in most cases and laparoscopic resection where possible is associated with improved outcomes. Anaesthetic management of PPGL cases represents a unique haemodynamic challenge both before and after tumour resection. In this article we describe the physiology of these tumours, their diagnosis, preoperative optimization methods, intraoperative anaesthetic management and management of postoperative complications.     

Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist and nabilone, a synthetic cannabinoid.     

Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist, and nabilone, a synthetic cannabinoid.     

Instrumented ligamentotaxis and stabilization of compression and burst fractures of dorsolumbar and mid-lumbar spines

Background:

Controversy continues regarding the best treatment for compression and burst fractures. The axial distraction reduction utilizing the technique employing the long straight rod or curved short rod without derotation to reduce fracture are practised together with short segment posterolateral fusion (PLF). Effects of the early postoperative mobilization without posterolateral fusion on reduction maintenance and fracture consolidation were not evaluated so far. The present prospective study is designed to assess the effectiveness of i) reduction and restoration of sagittal alignment, ii) no posterolateral fusion on the reduced, fractured vertebral body and injured disc, iii) fracture consolidation and iv) the fate of the unfused cephalad and caudal injured motion segments of the fractured vertebra.

Materials and Methods:

The study includes 15 Denis burst and two Denis type D compression fractures between T₁₂ and L₃. The lordotic distraction technique was used for ligamentotaxis utilizing the contoured short rods and pedicle screw fixator. Three vertebrae including the fractured one were fixed. The patients after surgery were braced for ten weeks with activity restriction for 2-4 weeks. The patients were evaluated for change in vertebral body height, sagittal curve, reduction of retropulsion, improvement in neural deficit. The unfused motion segments, residual postoperative pain and bone and metal failure were also evaluated.

Results:

The preoperative and postreduction percentile vertebral heights at, zero (immediate postoperative), at three, six and 12 months followup were 62.4, 94.8, 94.6, 94.5 and 94.5%, respectively. The percentages of the intracanal fragment retropulsion at preoperative, and postoperative at zero, 3, 6 and 12 months followup were 59.0, 36.2,, 36.0, 32.3, and 13.6% respectively.The preoperative and postreduction percentile loss of the canal dimension and at zero, three, six and 12 months were 52.1, 45.0, 44.0, 41.0 and 29% respectively suggesting that the under-reduced fragment was being resorbed gradually by a remodeling process. The mean initial kyphosis of 33° became mean 2° immediately after reduction and mean 3° at the final followup. The fractured vertebral bodies consolidated in an average period of ten weeks (range 8-14 weeks). The restored disc heights were relatively well maintained throughout the observation period. All paraparetic patients recovered neurologically. There were no postoperative complications.

Conclusion:

Instrument-aided ligamentotaxis for compression and burst fractures utilizing the short contoured rod derotation technique and the instrumented stabilization of the fractured spine are found to be effective procedures which contribute to the fractured vertebral body consolidation without recollapse and maintain the motion segment function.     

Incorporation and release of85Sr and14C-proline-hydroxyproline in mineral and collagen of bone and incisor teeth of growing rats

The extent to which exchange and reutilization processes of mineral tracers affect skeletal mineral accretion and resorption measurements was evaluated by comparing the rates of appearance and disappearance of⁸⁵Sr and¹⁴C-proline-hydroxyproline in bones and teeth in growing rats for 12 days following simultaneous parenteral injection of these tracers. Expressions for the relative rates of collagen synthesis and breakdown, which unlike mineral metabolism are considered not to be complicated by exchange phenomena, were based on¹⁴C-proline conversion to¹⁴C-hydroxyproline; the specific activity of the latter was determined. Both the mineral and the collagen specific activities reflected the rates and patterns of growth of the samples assayed; rapid growth and a short interval of time between formation and resorption of tissue in themetaphyseal bone which contains the cartilagineous growth plate, slow growth and an interval of time between formation and resorption of tissue indiaphyseal bone and incisor teeth which is longer than the 12 days of the experiment. However, in metaphyseal bone the specific activity collagen/mineral ratio dropped by one half during the 4–12 day interval in contrast to diaphyseal bone and incisor teeth in which no change in this ratio was observed during this period of time. The data indicate that collagen in the metaphyseal growth zone is removed by resorption before it has become fully mineralized, and that exchange is a relatively unimportant factor in the long term kinetics of bone mineral.

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Zusammenfassung Das Ausmaß, bis zu welchem Austausch- und Wiederverwendungsprozesse der mineralen Tracer die Messungen des mineralen Skelett-Auf- und Abbaues beeinflussen können, wurde ausgewertet; zu diesem Zweck wurde die Geschwindigkeit des Auftretens und Verschwindens von⁸⁵Sr und von¹⁴C-Prolin-Hydroxyprolin in Knochen und Zähnen von wachsenden Ratten während der 12 auf die simultane parenterale Injektion dieser Tracer folgenden Tage verglichen.Der Ausdruck für die relative Geschwindigkeit des Kollagen-Auf- und Abbaues, bei welchem im Gegensatz zum Mineralmetabolismus kein Mitwirken des Austauschphänomens vermutet wird, basiert auf der Umwandlung von¹⁴C-Prolin zu¹⁴C-Hydroxyprolin; die spezifische Aktivität des letzteren wurde bestimmt.Aus der spezifischen Aktivität des Minerals sowie jener des Kollagens konnten die Geschwindigkeit und die Art des Wachstums der untersuchten Proben ersehen werden, d.h.schnelles Wachstum und ein kurzes Zeitintervall zwischen Bildung und Resorption des Gewebes imKnochen der Metaphyse, die auch die knorpelige Wachstumsplatte enthält, und andererseitslangsames Wachstum und längeres Zeitintervall (länger als die 12 Tage des Experimentes) zwischen Bildung und Resorption des Gewebes imKnochen der Diaphyse und in den Schneidezähnen. Immerhin fiel die spezifische Aktivität des Kollagen/Mineral-Anteils im Knochen der Metaphyse während dem 4–12tägigen Zeitintervall auf die Hälfte, im Gegensatz zum Knochen der Diaphyse und der Schneidezähne, bei welchen während dieser Zeitspanne kein Unterschied in diesem Verhältnis beobachtet wurde.Diese Ergebnisse zeigen, daß Kollagen in der Wachstumszone der Metaphyse durch Resorption verschwindet, bevor es ganz mineralisiert ist, und daß der Austausch ein relativ unwichtiger Faktor in der Kinetik auf lange Sicht des Knochenminerals ist.

     

动静脉穿刺网络课件的开发及其应用

目的:确保护理教学效果,提高教学水平。方法:应用多项信息技术将动静脉穿刺技术制作成教学网络课件,并用于临床教学。结果:该课件在本校园网上运行半年余,2000余人次对其进行访问,受到师生好评。结论:该课件能及时反映动静脉穿刺的最新研究进展及具体操作步骤和使用方法,实现护理教学的直观性和交互性,对护理教学和临床带教指导有一定的借鉴作用。     

Physiology and pharmacology of nausea and vomiting

The physiology of nausea and vomiting is poorly understood. The initiation of vomiting varies and may be due to motion, pregnancy, chemotherapy, gastric irritation or postoperative causes. Once initiated, vomiting occurs in two stages, retching and expulsion. The muscles responsible for this sequence of events are controlled by either a vomiting centre or a central pattern generator, probably in the area postrema and the nearby nucleus tractus solitarius. Drugs which induce vomiting include ipecacuanha, a gastric irritant, and apomorphine, a dopamine-receptor agonist. Opioid drugs also induce vomiting, but opioid antagonists are not useful to treat nausea and vomiting. Anti-emetic drugs consist of a variety of neurotransmitter antagonists and may act in the periphery, the central nervous system or both sites. The most important drugs are antagonists at muscarinic, dopamine D₂, 5-HT₃, histamine H₁ and neurokinin NK₁ receptors. These drugs are discussed with particular attention to post-operative nausea and vomiting (PONV).