丙氨酰-谷氨酰胺二肽保护大鼠肝脏缺血再灌注损伤的实验研究

目的探讨丙氨酰-谷氨酰胺二肽(Ala-Gln)对肝脏缺血再灌注损伤(HIRI)的保护作用.方法采用大鼠HIRI模型(Pringle's法阻断入肝血流30 min),分谷氨酰胺组(G组)及对照组(C组),检测再灌注后血清肝生化酶、肝组织还原型谷胱甘肽(GSH)及超氧化物歧化酶(SOD)水平,对肝组织进行光镜与电镜检查,并计算术后24 h生存率.结果再灌注1h,G组血清ALT(499.25±120.84)U/L、LDH(6 956.00±2 443.93)U/L的水平均显著低于C组(ALT823.56±328.71,P<0.05;LDH11 715.31±2 993.50,P<0.01);再灌注24 h,两组血清ALT、LDH的水平均有显著恢复,但G组(ALT176.69±151.84;LDH415.38±213.68)水平仍显著低于C组(ALT548.25±257.25;LDH1 958.50±687.32;P<0.01).再灌注1 h及24 h,G组GSH的水平分别为(1 216.09±152.78)μg·g-1·p、(899.73±57.75)μg·g-1·p,均明显高于C组(分别为856.68±117.64,P<0.01;800.50±94.79,P<0.05);两组SOD的活性无统计学差异.G组肝脏组织学与细胞学损害均明显轻于C组.G组术后24h生存率为78.57%(11/14),明显高于C组的45.45%(10/22)(P<0.05).结论 Ala-Gln(Gln)对HIRI具有保护作用,而这种保护作用部分是通过维持肝脏组织中GSH的含量来介导的.     

肝脏Toll样受体4的激活与小鼠肝脏部分缺血再灌注损伤的关系

目的探讨TOLL样受体4(toll-like receptor 4,TLR4)的激活与肝缺血再灌注损伤的关系.方法以BALB/c小鼠复制肝脏部分缺血再灌注损伤模型,采用免疫组织化学法观察TLR4在肝脏的分布和表达量,同时监测血浆丙氨酸氨基转移酶(alanine aminotransferase,ALT)及门静脉血清内毒素(endotoxin,EN)和肿瘤坏死因子-α(tumor necrosis factor-alpha,TNF-α)的变化;再以TLR4先天性缺损小鼠C3H/Hej和野生型鼠C3H/Heouj为模型,观察ALT和门静脉血清TNF-α的变化.结果 1. BALB/c小鼠肝脏左中叶缺血1 h后,再灌注1、3 h,缺血肝叶内TLR4表达增加,且再灌注1 h最强,阳性细胞主要是枯否细胞及血管内中性粒细胞;2.门静脉血清EN在各时间点与假手术组相比无显著差异(P>0.05);3.再灌注3 h,TNF-α较假手术组升高[Hej(152±43)pg/ml vs. (18±10)pg/ml,n=6,t=5.26,P<0.01;Heouj(249±52)pg/ml vs. (25±13)pg/ml,n=6,t=7.24,P<0.01];4. Hej组小鼠肝功能损伤轻于Heouj组小鼠[再灌注1 h(662±106)pg/ml vs. (1 216±174)pg/ml,n=6,t=4.21,P<0.01;再灌注3 h(1 145±132)pg/ml vs. (2 958±187)pg/ml,n=6,t=13.72, P<0.01],且再灌注3 h其血清TNF-α水平明显低于Heouj组小鼠[(152±43)pg/ml vs. (249±52)pg/ml,n=6,t=3.94,P<0.01].结论 TLR4受体在肝脏缺血再灌注损伤过程中被激活,通过TNF-α等细胞因子介导参与了肝脏缺血再灌注损伤的过程.     

氯化钆抑制枯否细胞对大鼠肝脏缺血再灌注损伤的影响

目的探讨抑制枯否细胞对大鼠肝脏缺血再灌注损伤的影响。方法制作部分肝脏缺血再灌注大鼠模型80只,实验组注射氯化钆,对照组注射生理盐水,检测两组大鼠缺血前、再灌注后5min、1和6h血压、心率的变化,血清转氨酶(AST)、肿瘤坏死因子α(TNFα)和白细胞介素1(IL1)的水平及肝组织超微结构的改变。结果实验组再灌注6h血清TNFα和IL1为(0.475±0.069)μg/L和(0.221±0.056)μg/L,显著低于对照组的(0.831±0.167)μg/L和(0.335±0.127)μg/L(P<0.05),两组血压、心率和AST变化的差异也有统计学意义(P<0.05),实验组大鼠肝脏超微结构的损伤程度轻于对照组。结论抑制枯否细胞活化可减轻肝脏缺血再灌注损伤,枯否细胞在肝脏缺血再灌注损伤中的作用很重要。     

经肝动脉区域肝脏隔离灌注的研究

目的　研究幼猪经肝动脉区域隔离肝灌注的效果。　方法　14只幼猪随机分为2组:对照组(7只):采用经肝动脉灌注;实验组( 7只):左肝动脉及左肝静脉插管,进行左肝区域隔离肝灌注。灌注液为氨甲喋呤溶液(1mg/kg), 灌注时间为60min。于灌注5、10、20、30、45、60min时分别抽取外周血、肝脏灌注区域血、肝脏未灌注区域血(实验组)测定血药浓度; 灌注后切取左肝及右肝组织进行病理检查。　结果　在所有时间点, 实验组肝脏灌注区域氨甲蝶呤的血药浓度明显高于非灌注区和外周血(P<0. 01), 60min时最高, 达( 40. 211±3. 756 )μg/ml, 而非灌注区和外周血中仅为(1. 584±0. 347)μg/ml和(0. 773±0. 096)μg/ml。实验组灌注区域血药浓度均高于对照组肝脏血药浓度(P<0. 01), 60min时分别达(40. 211±3. 756)μg/ml和(4. 498±1. 643)μg/ml。实验组灌注区浓度-时间曲线下面积为218. 295μg/ml,而在对照组肝脏仅为260. 860μg/ml。病理检查提示两组灌注肝脏均有肝细胞浊肿、气球样细胞,但实验组肝脏灌注区域肝细胞坏死率为85. 7% (6 /7),明显高于对照组28. 6% (2 /7)。实验组肝脏未灌注区域无明显病理损害。　结论　动物实验证实经肝动脉区域隔离肝灌注是一种灌注及隔离效果好、肝功能损害小的区域化疗方法。     

超氧化物歧化酶对大鼠肝脏缺血再灌注损伤保护作用的体外实验

目的：探讨氧自由基清除剂对大鼠肝脏缺血再灌注损伤的保护作用及其机理。方法：将Wistar大鼠分成三组，各组通过门静脉插管，对肝脏进行原位灌洗，心脏搏动组以4℃HTK液灌洗；心脏停跳组在心脏搏动停止60min后，以同样方法灌洗肝脏；SOD实验组灌洗方法同心脏停跳组，但灌洗液中含有超氧化物歧化酶（SOD）7500IU。灌注结束后，快速切取肝脏，于4℃HTK液中保存24h，然后在体外以Krebs-Henseleit缓冲液再灌注45min。测定再灌注过程中的门静脉压力，收集再灌注液，进行血气分析，测定其中丙氨酸转氨酶（ALT）、谷氨酸乳酸脱氢酶（GLDH）及脂质过氧化物（LPO）的含量；切取肝组织，检测其能量底物总和（TAN）及细胞凋亡情况。结果：再灌注期间，SOD实验组的门静脉压力为（6．4±0．9）cmH20，明显低于心脏停跳组的（12．1±0．7）cmH20（P〈0．01）。随着再灌注时间的延长，灌注液中AL]r和GLDH的浓度不断升高，但SOD实验组明显低于心脏停跳组（P〈0．05）。心脏停跳组肝脏氧消耗量明显低于心脏搏动组（P〈0．01），而SOD实验组氧消耗量明显增加（P〈0．01）。SOD实验组的TAN为（7．6±0．4）μmol／g，明显高于心脏停跳组的（5．3±0．7）,μmol／g（P＜0．05）。SOD实验组灌注液中LPO的含量为（0．42±0．10）nmol／g，明显低于心脏停跳组的（0．98±0．18）nmol／g（P＜0．01）。心脏搏动组只有极少量的肝窦内皮细胞和肝细胞凋亡，SOD实验组中凋亡细胞的数量也非常有限，而在心脏停跳组，则有大量的肝窦内皮细胞发生凋亡。结论：在体外，SOD能显著减轻大鼠肝脏的缺血再灌注损伤，这可能与SOD抑制了氧自由基所致的细胞凋亡有关。     

逆行隔离灌注化疗可减轻对大鼠肝脏的毒性及药物的泄漏

目的 采用大鼠肝脏隔离灌注模型探讨逆行隔离灌注(RIHP)较顺行隔离灌注(IHP)能否减少正常肝组织损伤及化疗药物外周泄漏率.方法 将90只体重300～350 g雄性SD大鼠随机分为A、B、C三组,每组30只:A组为空白对照组,经肝动脉及门静脉灌注乳酸林格液,以下腔静脉为灌注液流出道;B组行IHP,经肝动脉灌注含有350 mg/kg的氟尿嘧啶(5-Fu),门静脉灌注乳酸林格液,以下腔静脉为灌注液流出道;C组行RIHP,经肝动脉灌注含有350 mg/kg的氟尿嘧啶(5-Fu),经下腔静脉灌注乳酸林格液,以门静脉为灌注液流出道.术后1、3、5、7 d分别行血清ALT测定及肝组织病理学检查;高效液相色谱分析仪检测B、C组术中外周血药浓度.结果 三组术后3 d存活率分别为90.0%、86.7%和90.0%,三者差异无统计学意义.三组血清ALT均在术后第一天达到峰值,A组为(481.6±207.6)μmol/L;B组为(1641.6±658.0)μmol/L;C组为(913.0±353.5)μmol/L.B、C组均显著高于A组(P＜0.05);B组显著高于C组(P＜0.05).B组与C组术中外周血药浓度峰值分别为(131.2±29.4)μg/ml和(65.3±28.4)μg/ml.两组外周浓度有显著性差异(P＜0.05).A组术后肝脏病理改变较轻,术后7 d基本恢复正常;B组术后肝脏病理学改变相对严重,术后7 d局部仍可见坏死灶;C组术后肝脏病理改变后较A组严重,但较B组轻,术后7 d基本恢复正常.结论 RIHP较之IHP能够显著减轻化疗药物对正常肝组织的毒副作用和药物的外周泄漏,有望成为一种对肝癌更加有效安全的区域化疗方法.     

自体原位移植肾缺血再灌注损伤模型的建立与环孢素A对移植肾的保护作用

目的建立一种新的移植肾缺血再灌注损伤(IRI)动物实验模型并寻找一种新的移植肾保护方法。方法40只兔随机分为A组(生理盐水对照组)、B组(单纯灌注液组)、C组[环孢素A(CsA)+灌注液组,CsA浓度为0.01‰,W/V]、D组(CsA+灌注液组,CsA浓度为0.03‰,W/V)。用套管针穿刺左肾动、静脉,灌注肾脏。原位低温保存2h后,切除右肾并开放左肾血流使左肾复灌。于术后6、24h分别取血标本,24h后取左肾标本,测定血尿素氮(BUN)、血肌酐(Cr),TUNEL法检测分析左肾小管上皮细胞凋亡率,免疫组织化学法测定左肾组织HSP70的表达。结果D组6、24hBUN为(8.60±0.25)mmol/L、(7.99±0.14)mmol/L;Cr为(79.90±1.37)μmol/L、(78.98±1.66)μmol/L,细胞凋亡指数为0.075±0.035,明显低于其他各组;HSP70表达为(0.211±0.025)μm2,明显高于其他各组。结论本模型能客观反映移植肾缺血再灌注损伤状态,0.03‰CsA复合肾灌注液能明显降低移植肾缺血再灌注损伤。     

丹参对大鼠肝脏低温保存损伤的保护作用

目的　研究丹参对大鼠肝脏低温保存损伤的保护作用。方法　采用大鼠肝脏离体非循环灌注模型 ,观察乳酸林格液 (LR液 )中加入不同剂量丹参后保存大鼠肝脏 1 2h的效果。结果　丹参组 ( 60 0mg/g)肝组织ATP含量 ( 6.0 8± 0 .67) μmol/g及分泌胆汁量 ( 1 0 5.6± 1 2 .4) μl/h明显高于对照组 ( 2 .52± 0 .31 ) μmol/g及 ( 57.4± 8.2 ) μl/h(P <0 .0 5) ,丹参组 ( 60 0mg/g)肝组织 2 ,3 二羟苯甲酸 ( 2 ,3 DHBA) ( 0 .1 54± 0 .0 1 3)nmol/g、2 ,5 DHBA( 1 .354± 0 .0 68)nmol/g及流出液天门冬氨酸转氨酶 (AST) ( 38.4± 3.7)U/L明显低于对照组 ( 0 .2 4 5± 0 .0 2 1 )nmol/g、( 2 .1 0 5± 0 .0 97)nmol/g及( 76.4± 9.2 )U/L ,差异有显著性 (P <0 .0 5)。结论　丹参可明显提高供体肝脏的保存效果 ,其作用机理可能主要与改善低温保存肝脏的能量代谢及抗氧自由基的作用有关     

中药复方“清下1号”对急性水肿性胰腺炎局部微循环损伤的作用

目的探讨大鼠急性水肿性胰腺炎(AEP)动物模型的早期微循环改变及中药复方清下1号（MCP-1）对AEP胰腺微循环的作用。方法用异硫氰酸荧光素-荧光标记红细胞(FITC-RBC)胰腺活体微循环技术、微血管树脂/墨汁灌注光镜和扫描电镜、透射电镜技术,用蛙皮缩胆囊肽诱发大鼠急性胰腺炎（AP）动物模型,观察36只Wistar大鼠的早期微循环改变、MCP-1应用后胰腺局部微循环的反应。结果与AEP自然病程组比较,MCP-1治疗组血清淀粉酶由（2997.7±801.4）?IU/L降至（1909.7±295.5）?IU/L（P<0.01）;胰腺间质炎性细胞浸润减少;腺泡细胞胞浆内空泡减少;毛细血管密度由（52.8±6.1）%增至（63.2±5.5）%（P<0.01);微血管管径由（4.5±0.4）?μm增至（5.9±0.6）?μm（P<0.05）;FITC-RBC显示胰腺微循环流速、流量增加,灌流稳定(0.87±0.06)nl/min（P<0.01)。结论MCP-1具有显著改善AP胰腺微循环的作用,抗AP胰腺局部微循环损伤是实现MCP-1疗效的重要机制。     

细胞凋亡在大鼠体外肝缺血再灌注损伤中的作用

目的探讨体外切肝不同术式对肝脏缺血再灌注损伤中肝细胞凋亡的影响。方法利用SD大鼠建立完全离体、半离体切肝动物模型,术后4、24h处死大鼠采取标本,通过病理、电镜观察肝脏形态学改变,免疫组织化学检测肝组织的核增殖抗原(PCNA)表达,原位末端标记法(TUNEL)检测细胞凋亡。结果完全离体组肝脏损害最严重,细胞凋亡阳性指数最高,再灌注后4h和24h分别为24.4±1.9,32.6±2.7,而半离体组为17.0±2.6,26.4±1.1,两组间差异有统计学意义(P<0.05);完全离体组再灌注4h和24h后PCNA的表达分别为66.6±2.5,77.2±1.5,明显高于半离体组的57.4±1.5,68.6±2.5(P<0.05)。结论肝窦内皮细胞凋亡及之后伴随的肝细胞凋亡是肝缺血再灌注后肝脏损伤的方式之一,在肝细胞凋亡的同时也存在肝细胞的增生,半离体体外肝手术对肝脏损伤相对轻、暴露良好,因此临床上应优先选择。     

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.