大鼠膀胱出口梗阻致膀胱重构的形态结构研究

目的观察大鼠膀胱出口部分梗阻不同时期的膀胱逼尿肌细胞增生、凋亡及间质中胶原纤维的变化情况。方法 Wistar大鼠40只,采用经会阴途径球部尿道部分结扎的方法建立膀胱出口部分梗阻模型,随机分为假手术组10只,梗阻2周组15只,梗阻4周组15只。采用免疫组化方法分析增殖细胞核抗原(PCNA)表达情况;通过末端转移酶标记(TUNEL)法测逼尿肌细胞凋亡指数;运用VG染色分析胶原纤维占膀胱逼尿肌面积比例变化情况。结果假手术组、梗阻2周组和梗阻4周组PCNA阳性表达率分别为(17.19±1.37)%、(50.74±3.15)%、(33.58±2.80)%,梗阻组之间差异有统计学意义(P0.05),梗阻组与假手术组之间差异有统计学意义(P0.05)。假手术组、梗阻2周组和梗阻4周组逼尿肌细胞凋亡指数分别为(20.22±1.70)%、(33.90±1.86)%、(51.18±3.30)%,梗阻组之间差异有统计学意义(P0.05),梗阻组与假手术组之间差异有统计学意义(P0.05)。假手术组、梗阻2周组和梗阻4周组胶原纤维占膀胱逼尿肌面积比例分别为(7.07±0.67)%、(13.19±1.50)%、(22.98±2.89)%,梗阻组之间差异有统计学意义(P0.01),梗阻组与假手术组之间差异有统计学意义(P0.01)。结论不同时期大鼠膀胱出口梗阻的膀胱逼尿肌形态结构的变化,可能是膀胱逼尿肌细胞增生、凋亡以及间质中胶原纤维占膀胱逼尿肌比例变化的综合作用结果。     

膀胱出口部分梗阻大鼠逼尿肌胆碱能和肾上腺素能受体变化的研究

目的观察大鼠膀胱出口部分梗阻后不同时间逼尿肌胆碱能（M）、肾上腺素能β及α1受体的变化。方法40只大鼠分为对照组、假手术组、梗阻2周组和梗阻5周组,每组10只。放射配基法测定逼尿肌M、β及α1受体密度和平衡解离常数。离体逼尿肌条拉力实验观察梗阻2周和5周后逼尿肌对氯化氨甲酰胆碱和异丙肾上腺素产生的收缩和舒张反应。结果4组M受体密度分别为（121．87±15．32）、（122．34±26．56）、（138．66±24．16）和（131．54±23．09）fmol／mg,β受体密度分别为（83．18±7．51）、（82．20±6．24）、（92．21±6．53）和（86．32±5．02）fmol／mg。梗阻组M受体和β受体密度与对照组及假手术组相比,差异有统计学意义（P〈0．05）,梗阻5周组较2周组降低（P〈 0．05）。4组α1受体密度分别为（30．08±3．51）、（31．07±2．99）、（29．56±3．21）和（28．31±1．16） fmol／mg,梗阻组与对照组及假手术组相比,差异无统计学意义（P〉0．05）。对照组M、β、α1受体平衡解离常数分别为（2．18±0．13）、（5．63±0．44）、（4．68±0．34）mmol／L,假手术组分别为（2．54±0．96）、（5．74±0．41）、（4．79±0．42）mmol／L,梗阻2周组分别为（2．22±0．36）、（5．66±0．32）、（4．56±0．33）mmol／L,梗阻5周组分别为（2．32±0．25）、（5．56±0．19）、（4．55±0．18）mmol／L,组间比较差异无统计学意义（P〉0．05）。氯化氨甲酰胆碱和异丙肾上腺素引起逼尿肌条的收缩和舒张均呈浓度依赖性反应（P〈0．05）。结论大鼠膀胱出口部分梗阻后可能引起逼尿肌M、β及α1受体的改变,导致膀胱功能变化。     

膀胱出口梗阻后大鼠逼尿肌细胞内质网形态及GRP78表达的研究

目的观察膀胱出口部分梗阻后膀胱重构中,逼尿肌平滑肌细胞内质网形态及内质网应激标志性蛋白——葡萄糖调节蛋白78(GRP78)的表达情况,探讨内质网应激在膀胱重构机制中可能的作用。方法雄性Wistar大鼠40只,随机分为假手术组10只,梗阻2周组15只,梗阻4周组15只,采用经会阴途径球部尿道部分结扎的方法建立膀胱出口部分梗阻模型。采用透射电子显微镜观察逼尿肌平滑肌细胞的超微结构,通过免疫组化和Real-time PCR分别检测逼尿肌中GRP78蛋白及mRNA表达变化。结果假手术组、梗阻2周组和梗阻4周组大鼠膀胱逼尿肌细胞GRP78蛋白阳性表达率分别为(3.37±0.38)%、(51.22±0.27)%、(27.02±1.85)%,梗阻2周组大鼠膀胱逼尿肌中GRP78阳性表达明显增多,与假手术组相比有明显差异(P0.01),梗阻4周组大鼠逼尿肌中GRP78阳性表达增多,与假手术组相比有明显差异(P0.01),但比梗阻2周组表达量减少(P0.01)。各组GRP78mRNA表达量分别为(22.21±1.58)、(30.62±2.49)、(24.52±2.24),梗阻2周组大鼠膀胱逼尿肌细胞GRP78mRNA表达较假手术组明显增加(P0.01);与梗阻2周组相比,梗阻4周组大鼠膀胱逼尿肌细胞GRP78mRNA表达量下降,有显著性统计学意义(P0.01),梗阻4周组与假手术组相比无统计学意义。结论在梗阻后膀胱重构过程中,逼尿肌平滑肌细胞内质网形态有明显损伤性变化,GRP78蛋白及mRNA表达水平明显增加,提示内质网应激参与膀胱重构的进展。     

兔膀胱出口部分梗阻所致逼尿肌超微结构的改变

目的　观察兔膀胱出口部分梗阻后逼尿肌细胞超微结构的改变。　方法　建立雄性兔膀胱出口部分梗阻动物模型 ,利用透射电镜观察其逼尿肌细胞内超微结构 ,应用ImagineTool图像分析软件检测粗面内质网面积和线粒体密度。　结果　梗阻组逼尿肌细胞内单位面积平均 1 1 5 .2 8μm2 ,胞质中粗面内质网面积 (5 .377± 2 .31 8) μm2 ,较对照组的 (0 .476± 0 .31 9) μm2 明显扩大 ;线粒体相对密度为 1 .0 2 7± 0 .0 64 ,较对照组的 0 .830± 0 .0 58明显下降 ,P均 <0 .0 1。　结论　膀胱出口部分梗阻后逼尿肌细胞内质网扩张 ,提示其合成蛋白质功能增强 ,从而引起膀胱壁增厚 ;而线粒体水肿明显 ,密度下降 ,提示逼尿肌细胞能量代谢障碍 ,导致其收缩功能下降     

雄性兔膀胱出口部分梗阻所致逼尿肌功能障碍的研究

目的探讨膀胱出口部分梗阻所致逼尿肌功能改变.方法取新西兰雄性白兔14只,梗阻组和对照组各7只.梗阻组行手术人为造成膀胱出口部分梗阻,饲养5周后解剖膀胱,测定膀胱重量、容量;检测逼尿肌功能;对膀胱逼尿肌细胞超微结构进行观察.结果梗阻组膀胱重量为(12.129±1.627)g,对照组膀胱重量为(3.762±1.067)g(P＜0.05);梗阻组膀胱容量为(64.000±6.272)m1,对照组膀胱容量为(94.432±12.850)ml(P＜0.05);单位重量膀胱逼尿肌对各种刺激反应性均明显下降(P＜0.05或P＜0.01);梗阻膀胱逼尿肌细胞中粗面内质网明显扩张,线粒体水肿.结论通过手术可人为建立膀胱出口部分梗阻动物模型;膀胱出口部分梗阻将导致逼尿肌功能障碍;逼尿肌功能变化与其形态学变化相关.     

膀胱出口梗阻引起逼尿肌肌球蛋白重链亚型表达改变的实验研究

目的检测膀胱出口梗阻(BOO)后逼尿肌肌球蛋白重链亚型表达改变。方法雄性新西兰白兔14只,分为梗阻组和对照组,每组7只。梗阻组行手术部分结扎膀胱颈部,制成BOO动物模型。5周后两组均切除膀胱并测定膀胱重量、容量,提取逼尿肌组织蛋白,行聚丙稀酰胺凝胶电泳,蛋白印迹法检测平滑肌肌球蛋白重链亚型(SM1和SM2)表达的改变;提取逼尿肌组织mRNA行RTPCR反应检测平滑肌肌球蛋白重链亚型SM1和SM2mRNA表达的改变。结果梗阻组和对照组膀胱重量分别为(13.8±4.4)g和(3.7±0.5)g,P<0.01;两组膀胱容量分别为(70.4±18.9)ml和(109.0±29.0)ml,P<0.05。梗阻组肌球蛋白重链亚型SM2∶SM1为1.2∶1.0,SM2mRNA∶SM1mRNA为1∶1。对照组分别为3∶1和3∶1。结论逼尿肌肌球蛋白重链亚型SM1、SM2的表达与逼尿肌的功能状态密切相关,随着SM1、SM2比例的改变,肌肉收缩功能亦发生相应变化。     

维生素E对膀胱出口部分梗阻后膀胱功能的保护作用

目的探讨维生素E对兔膀胱出口部分梗阻引起膀胱功能改变的保护作用.方法新西兰雄兔28只随机分为A组6只、B组6只、C组8只、D组8只,A、B、C组正常饮食,D组每日给予维生素E 600 mg,4周后B组建立假手术模型,C、D组建立膀胱出口部分梗阻模型.术后4周各组进行尿动力学检查、膀胱称重、RT-PCR检测膀胱组织肌质网钙泵蛋白(SERCA2)mRNA水平、Western blot检测SERCA2和肌动蛋白表达水平.结果正常A组和假手术B组各项参数比较差异均无统计学意义,合并为对照组(A+B组).膀胱重量C组为(13.07±1.71)g、D组为(11.80±2.01)g,约为对照组(2.81±0.30)g的4倍(P＜0.01).尿动力学检查最大逼尿肌压力D组为(37.38±4.04)cm H2O,大于C组的(24.13±4.54)cm H2O和对照组的(22.70±1.89)cm H2O(P＜0.05);膀胱容量D组为(83.00±13.05)ml、对照组为(67.00±7.22)ml,均大于C组的(45.13±6.63)ml(P＜0.05);膀胱顺应性D组为(8.18±1.95)ml/cm H2O、对照组为(6.67±0.90)ml/cmH2O,均好于C组(3.35±0.68)ml/cm H2O(P＜0.05);SERCA2 mRNA表达D组为1.45±0.16、对照组为1.41±0.05,高于C组的0.97±0.11(P＜0.05);SERCA2蛋白表达D组为1.90±0.19、对照组为2.18±0.23,高于C组的1.35±0.16(P＜0.05);而三组肌动蛋白表达差异无统计学意义.结论预先服用维生素E可以提高梗阻后SERCA2基因转录和表达水平,可能是保护膀胱功能的机制之一.     

网状蛋白、支架蛋白及转化生长因子β1mRNA在膀胱出口梗阻性逼尿肌中的表达及意义

目的探讨膀胱出口梗阻(BOO)性逼尿肌中网状蛋白、支架蛋白及转化生长因子β1 (TGF-β1)mRNA表达的改变及意义。方法BOO组患者16例,为良性前列腺增生(BPH)并经尿动力学压力-流率检查结果证实为高压-低流型;对照组5例,为外伤等情况入院并排除下尿路梗阻病史者。2组患者均行开放手术治疗,同时切取膀胱上壁组织2 cm×1 cm×1 cm,标本行RT-PCR反应,检测膀胱逼尿肌中网状蛋白、支架蛋白及TGF-β1mRNA表达的改变并比较TGF-β1与网状蛋白、支架蛋白之间的线性相关性。结果BOO组网状蛋白、支架蛋白及TGF-β1mRNA的表达量分别为(20．0±25．0)×106、(25．0±31．0)×106、(3．60±7．30)×106拷贝数／μg总RNA,对照组分别为(2．2±0．9)×106、(2．4±2．1)×106、(0．18±0．13)×106拷贝数／μg总RNA,2组比较差异均有统计学意义(P<0．01)。TGF-β1与网状蛋白、支架蛋白之间的直线相关系数r分别为0．952和0．898,P值均<0．001,呈线性正相关。结论膀胱逼尿肌中网状蛋白、支架蛋白及TGF-β1表达改变均与逼尿肌的功能状态密切相关。     

电压依赖性钾通道和逼尿肌不稳定关系的实验研究

目的观察电压依赖性钾（Kv）通道在逼尿肌不稳定（DI）中的表达变化及作用，探讨DI的发生机理及Kv通道作为治疗靶点的可行性。方法25只雌性Wistar大鼠建立膀胱出口部分梗阻模型，6周后行膀胱测压获得DI模型。制备逼尿肌肌条，离体收缩实验观察Kv通道阻断剂对逼尿肌肌条自发性收缩功能的影响；RT-PCR技术检测逼尿肌中Kv通道mRNA的表达。10只正常大鼠为对照组。结果Kv通道阻断剂4-氨基吡啶干预后，对照组逼尿肌肌条的收缩频率、幅度变化率分别为（84．3±23．8）％、（45．9±16．1）％，DI组分别为（34．2±11．4）％、（14．2±5．1）％，DI组均低于对照组（P〈0．05）。对照组逼尿肌中Kv通道亚型Kv2．1、Kv1．5的相对含量分别为0．75±0．11、0．61±0．09，DI组分别为0．65±0．09、0．39±O．07，DI组Kv通道含量减少，其中Kv1．5减少更明显（P〈0．01）。结论Kv通道反馈调节逼尿肌收缩，此机制在DI组明显减弱，可能导致逼尿肌收缩过度活跃。DI组Kv通道作用下调可能与逼尿肌中Kv通道亚型特别是Kv1．5的mRNA表达减少有关。Kv1．5也许可以作为治疗DI的较好靶点。     

尿动力学检查中非压力-流率指标拟诊前列腺梗阻的临床研究

目的　探讨用非压力 流率 (P F)指标拟诊良性前列腺增生 (BPH)患者膀胱出口梗阻(BOO)的可能性。　方法　计量资料用 x±s表示 ,两样本均数及两样本率比较采用t检验 ,对选定的非P F指标在确诊梗阻组、无梗阻组间进行比较 ,分析其特点。　结果　 5 0 4例BPH患者中 ,获得满意P F结果并确诊BOO者 2 5 2例 ,无BOO者 5 2例。无满意P F结果 ,但拟诊梗阻者 2 0 0例。BOO组与无BOO组结果比较 :具有前列腺典型尿道压力分布图 (UPP)曲线者分别占 87.3%和 5 3.8% (P<0 .0 5 ) ;充盈末期逼尿肌无抑制收缩发生率分别为 2 2 .2 %和 7.7% (P <0 .0 5 ) ;膀胱开口压分别为(90 .4± 38.5 )cmH2 O(1cmH2 O =0 .0 98kPa)和 (46 .9± 2 0 .7)cmH2 O(P <0 .0 5 ) ;排尿期最大逼尿肌压力分别为 (12 4 .9± 4 2 .9)cmH2 O和 (6 6 .4± 2 1.7)cmH2 O(P <0 .0 5 ) ,其余非P F指标间无明显差别。 2 0 0例无满意P F结果但拟诊BOO的患者中 ,16 3例的最大逼尿肌压力平均为 (12 0± 4 2 .8)cmH2 O ,10 0例患者膀胱开口压平均为 (98.4 6± 4 2 )cmH2 O ,测得逼尿肌痉挛 97例 ,测得前列腺典型UPP曲线 2 8例 (多数因留置导尿 ,不能获得正常UPP曲线 )。　结论　部分非P F指标可以作为辅助诊断BOO依据 ,包括 :最大逼尿肌压力 >80cmH2 O ,膀     

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.