细胞外信号调节激酶和P38蛋白激酶在自体移植静脉中的表达

目的研究丝裂原活化蛋白激酶亚单位细胞外信号调节激酶(ERK)和p38蛋白激酶(p38 MAPK)在移植静脉血管重塑过程中的表达.方法选Wistar大鼠80只,建立自体移植静脉模型,术后随机分为6 h、24 h、3 d、7 d、2周、4周、6周及8周组,于相应时点取材,半定量逆转录PCR法检测移植血管中ERK和p38 MAPK的mRNA表达;Western蛋白印迹定量检测ERK和p38 MAPK的蛋白产物及磷酸化蛋白产物表达;脱氧核苷酸末端转移酶末端标记法(TUNEL)检测血管平滑肌细胞(VSMC)凋亡的变化;免疫组化检测增殖细胞核抗原(PCNA)的表达.结果移植静脉术后6 h,ERK1和p38 MAPK的mRNA表达均明显增强,与正常静脉组比较差异均有显著性意义(P＜0.01);ERK1mRNA表达在移植后7 d达高峰,表达值为(33.2±14.2)%,p38 MAPK的mRNA表达于术后2周达到高峰,表达值为(58.8±26.2)%,与其余各时点比较差异有显著性意义(P＜0.01).Western蛋白印迹提示ERK1/2在术后1～2周达高峰,6周时逐渐恢复至正常水平;而p38 MAPK则在移植后2～4周达高峰,之后开始减少,8周时仍维持一定表达量(1/4～1/2).ERK1与PCNA表达呈正相关(r=0.759 6,P＜0.01),p38 MAPK与凋亡呈正相关(r=0.892 2,P＜0.01).结论MAPK的激活是移植静脉内膜增生以及血管重塑的关键环节,可能成为防治移植静脉狭窄、闭塞的新的治疗靶点.     

p38 MAPK在自体移植静脉中的表达及其意义

目的　研究丝裂原活化蛋白激酶p3 8MAPK信号传导通路在自体移植静脉中的表达。方法　Wistar大鼠 80只 ,建立自体移植静脉模型。术后随机分为 6,2 4h ,3 ,7d和 2 ,4,6,8周等 8组 ,于相应时点取材 ,半定量逆转录PCR检测移植血管中p3 8MAPK的mRNA表达 ,Western蛋白印迹定量检测 p3 8的蛋白产物及磷酸化蛋白产物表达 ,原位杂交和免疫组化方法定位p3 8mRNA及蛋白表达。结果　移植静脉术后 6hp3 8的mRNA表达即较正常静脉明显增强 (P <0 .0 1) ,并于术后 2周达高峰 ,表达值为 (59± 2 6) % ,与 4,6,8周比较差异极显著 (P <0 .0 1)。Western蛋白印迹提示 p3 8在移植 2～ 4周达高峰 ,之后开始减少 ,8周时仍维持一定表达量 (1/4～ 1/2 )。原位杂交及免疫组化提示阳性表达多定位于移植血管中层或增生内膜中的血管平滑肌细胞 (VSMCs)。结论　p3 8MAPK通路的激活参与了移植静脉的内膜增生以及血管重塑 ,可望成为防治移植静脉狭窄闭塞的治疗靶点     

细胞外信号调节激酶在自体移植静脉中的表达

目的 探讨细胞外信号调节激酶(ERKs)在自体移植静脉中表达的变化规律。方法Wistar大鼠 80只,建立自体静脉移植模型,术后随机分为 6、24 h,3、7 d,2、4、6、8周等 8组,半定量逆转录-聚合酶链反应(RT-PCR)检测移植血管中 ERK1 mRNA表达,Western蛋白印迹定量ERK1/2的蛋白产物以及磷酸化蛋白产物的表达,原位杂交定位 ERK1 mRNA、免疫组织化学方法检测 ERK和增殖细胞核抗原(PCNA)的蛋白产物表达。结果 静脉移植后 6 h,ERK1 mRNA表达明显增强,与正常静脉比较差异有显著性(P<0.01),在移植7 d表达达高峰(33.2±14.2)％,与其余时点比较差异有显著性(P<0.01),4周后恢复至正常水平。Western蛋白印迹提示 ERK1/2在术后1～2周达高峰。阳性表达多定位于血管平滑肌细胞(VSMCs),ERK1与PCNA表达呈正相关(r=0.759 6,P<0.01)。结论 ERKs信号转导通路的激活可能是内膜增生的关键环节,可能成为防治移植血管狭窄、闭塞新的靶点。     

雷帕霉素靶蛋白及其底物在自体移植静脉中的表达及意义

目的研究雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR）及其底物——核糖体蛋白s6激酶（p70s6k）、真核细胞启动子4E结合蛋白1（4E—BP1）在自体移植静脉中表达的动态变化规律,探讨其与内膜增生的关系及意义。方法Wistar大鼠64只,建立自体静脉移植模型,随机分为8组,分别在移植后6h,1、3d,1、2…468周切取移植静脉。逆转录-聚合酶链反应（RT—PCR）联合原位杂交方法检测移植血管中mTOR及其底物pT0s6k和4E—BPI的mRNA表达,Western蛋白印迹或免疫组化方法检测mTOR、pT0s6k和4E—BP1的蛋白产物表达,同时检测增殖细胞核抗原（PCNA）的表达。结果静脉移植1—3d即出现mTOR和pT0s6k的mRNA表达增强,3d-2周达到高峰,与其他组比较差异有统计学意义（P〈0．01）,6—8周逐渐恢复正常;而4E—BP1的mRNA表达在移植后1d开始降低,1周表达最低,之后表达开始增强,4～6周为表达高峰,与其他组比较差异有统计学意义（P〈0．01）。Western蛋白印迹提示mTOR和pT0s6k蛋白产物在移植后1周表达明显增加,2～4周达到高峰,8周恢复至正常水平;而4E—BP1蛋白产物在移植后1周表达最少,4—6周增加达到高峰,8周仍维持一定的表达量。原位杂交及免疫组化结果提示阳性细胞多定位于移植静脉新生内膜和中膜血管平滑肌细胞,mTOR及其底物与PCNA分布基本一致。结论mTOR信号通路在血管移植后即被激活并与内膜增生关系密切,可能成为防治移植血管狭窄、闭塞的有效靶点。     

Egr-1DNA酶抑制自体移植静脉内膜增生的实验研究

目的 探讨早期生长反应基因-1 (Egr-1) DNA酶(Egr-1 DNA enzyme,EDRz)对血管平滑肌细胞(VSMC)增殖和内膜增生的抑制作用,从而证实基因治疗静脉移植后狭窄、闭塞的可行性.方法 构建EDRz,建立自体静脉移植模型,将大鼠右颈总静脉端-端吻合于肾下腹主动脉,EDRz转染移植静脉,分别于移植后1、2、6、24 h及3、7、14、28、42 d切取移植静脉标本,每个时相按随机数字表法随机抽取10只大鼠.荧光显微镜下观察EDRz转染移植静脉情况;应用原位杂交和RT-PCR方法检测Egr-1 mRNA的表达;应用Western蛋白印迹和免疫组织化学方法检测Egr-1蛋白表达情况;HE染色光镜下观察组织学形态.结果 ①EDRz转染移植静脉情况:移植后1h时,EDRz主要位于移植静脉的外膜、中膜和部分内皮细胞;2、6及24 h时,EDRz则主要位于移植静脉的中膜;7d时,EDRz主要位于移植静脉的内膜; 14、28及42 d时未检测到EDRz的表达.②Egr-1 mRNA表达结果.RT-PCR检测结果:转染EDRz后1h时,Egr-1 mRNA表达出现高峰,2、6及24 h表达下降,3d时表达微弱,移植后7、14、28及42 d未见Egr-1 mRNA的表达,转染EDRz后1h时Egr-1 mRNA表达明显高于其余各时相(P＜0.01).原位杂交检测Egr-1 mRNA表达的变化趋势与RT-PCR结果基本一致.③Egr-1蛋白表达结果.Western蛋白印迹结果:正常静脉中未检测到Egr-1蛋白阳性表达.转染EDRz后2h时,出现Egr-1蛋白阳性表达,6h、24 h及3d时其表达逐渐降低,移植后1h时和移植后7、14、28及42 d时未见Egr-1蛋白阳性表达.移植后2h时的Egr-1蛋白表达的吸光度值高于其他时相(P＜0.01).免疫组织化学方法检测的Egr1蛋白阳性表达的变化趋势与Western蛋白印迹结果基本一致.④EDRz转染移植静脉与未转染同期相比VSMC的增殖程度和内膜厚度明显减轻.结论 EDRz通过减少Egr1在自体移植静脉中的表达,可有效地抑制自体移植静脉中VSMC增殖和内膜增生,可用来防治自体静脉移植后所导致的血管狭窄、闭塞.     

反义寡核苷酸抑制早期生长反应基因1表达对移植静脉内膜增生的影响

目的 研究反义寡脱氧核苷酸(antisense oligodeoxynucleotides,ASODN)抑制早期生长反应基因1(early growth response gene-1,Egr-1)表达对移植静脉血管平滑肌细胞增殖和内膜增生的影响.方法构建Egr-1 ASODN,建立自体静脉移植模型,Egr-1 ASODN转染移植静脉,术后随机分为1、2、6、24 h,3、7、14、28、42 d组,以未应用Egr-1 ASODN的大鼠为对照组.荧光显微镜检测Egr-1 ASODN转染移植静脉情况;应用原位杂交和RT-PCR方法检测Egr-1 mRNA的表达;联合应用免疫组织化学方法和Western blot检测Egr-1蛋白表达情况.结果 实验组移植1 h,Egr-1 ASODN主要位于移植静脉的外膜、中膜和部分内皮细胞(荧光灰度值为67±11),移植2 h至24 h,Egr-1 ASODN则主要位于移植静脉的中膜,移植7 d,Egr-1 ASODN主要位于移植静脉的内膜.移植后期未检测到Egr-1 ASODN的表达.Egr-1 mRNA的表达只呈现一个高峰(基因表达值1.8±0.5).移植早期Egr-1蛋白表达主要位于中膜的VSMC、部分单核细胞和内皮细胞,而移植后期在中膜和新生内膜的VSMC都未检测到Egr-1蛋白的表达.与对照组相比VSMC的增殖程度和内膜厚度均明显减轻(P＜0.01).结论 Egr-1 ASODN可显著抑制移植静脉的内膜增生,其作用可能是通过抑制Egr-1基因及其蛋白产物表达,从而抑制VSMC增殖、促进其凋亡而实现的.     

脂质体与腺病毒转染EDRz抑制自体移植静脉内膜增生的比较研究

目的探讨以脂质体和腺病毒为载体,早期生长反应基因-1 DNA酶(Egr-1 DNA enzyme,EDRz)局部外用对自体移植静脉血管平滑肌(VSMC)增殖和内膜增生的抑制作用。方法大鼠建立自体静脉移植模型后随机分为脂质体组、腺病毒组和对照组,两实验组分别用脂质体-EDRz和腺病毒-EDRz涂抹移植静脉行在体转染。于术后1,2,6,24 h及3,7,14,28 d取材,荧光显微镜检测移植静脉的转染情况;采用原位杂交方法检测Egr-1 mRNA的表达;用免疫组织化学方法检测Egr-1蛋白表达,同时进行组织形态学观察。结果术后1 h,EDRz主要位于移植静脉的外膜、中膜和部分内皮细胞。脂质体组荧光灰度值为70.3±13.5,腺病毒组荧光灰度值为60.5±11.2。术后2～24 h,EDRz主要位于移植静脉的中膜;移植7 d,EDRz主要位于移植静脉的内膜。移植早期Egr-1蛋白表达主要位于中膜的血管平滑肌细胞(VSMC)和部分单核细胞、内皮细胞;移植后期未检测到Egr-1 DNA酶的表达。移植后期在中膜和新生内膜的VSMC均未检测到Egr-1蛋白的表达。移植2 h阳性表达率,脂质体组为(15.3±4.2)%,腺病...     

mTOR信号转导通路在自体移植静脉中的表达及意义

目的研究哺乳类动物雷帕霉素靶蛋白(mTOR)在自体移植静脉中表达的动态变化规律。方法Wistar大鼠64只,建立自体静脉移植模型,随机分为8组,分别在移植后6 h,1、3 d,1、2、4、6、8周切取移植静脉。逆转录PCR结合原位杂交研究移植血管中mTOR的tuRNA表达,Western blot联合免疫组化检测mTOR蛋白产物表达的变化,同时检测增殖细胞核抗原(PCNA)。结果逆转录PCR扩增在静脉移植1-3 d即出现mTOR mRNA表达增强,1-2周达到高峰,表达值分别为(48±18)％和(33±11)％,与其他组比较差异有统计学意义(P<0．01),6-8周逐渐恢复正常。免疫组化及Western蛋白印迹均提示mTOR蛋白在移植3 d表达明显增多,2-4周达到高峰,分别为(29±8)％和(31±6)％,与其他组比较差异有统计学意义(P<0．01),8周恢复至正常水平。mTOR蛋白产物表达与PCNA表达呈正相关(r=0．756,P<0．01)。结论mTOR在血管移植后的过程中被激活,与内膜增生关系密切,可能是防治移植血管狭窄、闭塞的干预靶点。     

细胞间粘附分子-1在自体移植静脉中表达的动态变化

目的　研究细胞间粘附分子 (ICAM ) 1在自体移植静脉中表达的动态变化规律 ,探讨其与内膜增生的关系及意义。方法　Wistar大鼠 5 6只 ,建立自体静脉移植模型 ,随机分为 7组 ,分别在移植后 1、3d ,1、2、4、6、8周切取移植静脉。半定量逆转录 聚合酶链反应 (RT PCR)结合原位杂交定位研究移植血管中ICAM 1mRNA的表达 ,Westernblot联合免疫组织化学方法检测I CAM 1蛋白产物表达的变化。结果　ICAM 1mRNART PCR扩增见静脉移植 1～ 3d即出现表达增强 ,1～ 2周达到高峰 ,表达值分别为 ( 3 6.6± 12 .9) %和 ( 5 8.7± 11.1) % ,与其他组比较差异有显著性 (P <0 .0 1) ,6～ 8周逐渐恢复正常 ,与原位杂交变化趋势基本一致。免疫组织化学结果见I CAM 1在移植 1～ 7d表达明显增多 ,2～ 4周达到高峰 ,分别为 ( 2 3 .5± 7.1) %和 ( 2 0 .6± 9.2 ) % ,与其他组比较差异有显著性 (P <0 .0 1) ,8周恢复至正常水平 ,与Western蛋白印迹结果一致。结论ICAM 1与移植静脉内膜增生关系密切 ,可能成为防治内膜增生以及血管移植后狭窄闭塞一个新的治疗靶点。     

局部血管紧张素Ⅱ水平与核因子-κB、p38丝裂素活化蛋白激酶信号传导通路活化在人门静脉高压症脾静脉血管病变中的作用

目的 探讨血管紧张素Ⅱ(AngII)与核因子(NF)-κB、p38丝裂素活化蛋白激酶(p38MAPK)信号传导通路活化在人门静脉高压症(PHT)脾静脉血管病变中的作用及其机制.方法 PHT组为乙肝后肝硬化门静脉高压症患者26例;对照组选取因外伤性脾破裂行脾切除术患者10例.放免法(RIA)检测脾静脉中AngII水平;免疫组织化学法测定脾静脉中NF-κB、Phospho-p38蛋白的表达.蛋白免疫印迹法检测脾静脉及体外培养的脾静脉血管平滑肌细胞的NF-κB 、Phospho-p38蛋白的表达.结果 PHT组脾静脉组织AngII为(248.91±48.31)ng/L,显著高于对照组AngII为(143.35±36.45)ng/L(P<0.01).免疫组织化学和蛋白免疫印迹均显示PHT组脾静脉NF-κB 、Phospho-p38蛋白的表达较对照组明显增强.体外培养脾静脉血管平滑肌细胞(VSMC),AngII在1×10-8～1×10-6mol/L浓度范围内,AngII以浓度依赖性方式增加人脾静脉VSMC中NF-κB 、Phospho-p38蛋白的表达.结论 门静脉高压症时脾静脉组织AngII水平升高,NF-κB、Phospho-p38蛋白表达增加.AngII能激活脾静脉血管平滑肌细胞NF-κB、p38信号传导通路.门静脉高压症时AngII可能通过激活P38和NF-κB信号对传导通路门静脉高压症的形成和维持可能起重要作用.     

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.     

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.

     

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.     

Principles and Practice of Hemofiltration and Hemodiafiltration

There is growing interest in the convective dialysis therapies, hemofiltration (HF) and hemodiafiltration (HDF). Both require dialysis membranes which are highly permeable to solutes as well as fluid, and in both cases large volumes of ultrafiltration are the condition for convective transport. In HDF the convection is combined with diffusion, and as a consequence, maximum clearance over the entire molecular weight spectrum is achieved. Optimal forms of HDF provide urea clearance 10–15% higher than the corresponding diffusive mode. The larger the solute, the greater is the impact of convection, and β₂-microglobulin (β₂m) levels may be up to 70% reduced. Traditional postdilution HF provides high clearance of medium sized and large molecules. Satisfactory clearance of small solutes requires blood flows in excess of 500 ml/min. With access to practically unlimited volumes of substitution solution through on-line ultrafiltration, predilution HF can now be used. This increases the clearance of small solutes to an acceptable range. For HDF as well as HF, large patient populations consistently treated for longer periods of time are needed to make valid outcome comparisons with other therapies.     

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.     

骨折不愈合与延迟愈合的成因与治疗

目的探讨骨折不愈合与延迟愈合的成因、报肯治疗的方法与设果。方法对1990年7月～2004年12月间收治的107例骨折不愈台、54例骨折延迟愈合2例先天性胫骨骨不连进行回顾性研究，分析原因，随访治疗结果。18例延迟愈合行保守治疗，本组其他145例行手术治疗，结果除2例先天性胫骨骨不连外，其余161例的成因中均有医源性因素。10例失去随访，153例平均随访17（6-28）个月，骨折均获骨性连接，愈合时间平均10（6-14）个月，肢体功能恢复良好，结论医源性技术缺陷是骨折不愈合与延迟愈合的主要原因，针对各种不同因素进行合理治疗可获得满意效果。     

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.