右美托咪定对神经病理性痛大鼠脊髓Toll样受体4和NF-κB表达的影响

目的 评价右美托咪定对神经病理性痛大鼠脊髓Toll样受体4和NF-κB表达的影响.方法 健康成年雄性Wistar大鼠108只,6～8周龄,体重180 ～ 220 g,采用随机数字表法,将其分为3组(n=36):假手术组(S组)、神经病理性痛组(NP组)和右美托咪定组(D组).采用坐骨神经慢性压榨性损伤法制备神经病理性痛模型,D组于术后即刻开始至处死前1d腹腔注射右美托咪定50μg/kg,1次/d.S组和NP组以等容量生理盐水替代.于术前1d,术后3、7、14 d时测定机械痛阈和热痛阈,并于术后测定痛阈后处死,取L4-6脊髓组织,采用RT-PCR法测定TLR4 mRNA和NF-κB mRNA的表达,采用免疫组织化学法测定脊髓背角TLR4和NF-κB的表达水平.结果 与S组比较,NP组和D组机械痛阈和热痛阈降低,TLR4及其mRNA、NF-κB及其mRNA的表达上调(P＜0.05);与NP组比较,D组机械痛阈和热痛阈升高,TLR4及其mRNA、NF-κB及其mRNA的表达下调(P＜0.05).结论 右美托咪定减轻大鼠神经病理性痛的机制与抑制TLR4和NF-κB表达有关.     

右美托咪啶对慢性神经病理性痛大鼠脊髓背角神经元凋亡的影响

目的 评价右美托咪啶对神经病理性痛大鼠脊髓背角神经元凋亡的影响.方法 健康成年雄性SD大鼠72只,体重180～220 g,采用随机数字表法,将其随机分为3组(n=24):假手术组(S组)、慢性神经病理性痛组(CNP组)和右美托咪啶组(D组).S组仅分离坐骨神经但不结扎,CNP组和D组采用结扎坐骨神经的方法制备大鼠神经病理性痛模型,D组于结扎坐骨神经结束开始至处死前,腹腔注射右美托咪啶50μg/kg,1次/d,S组和CNP组注射等容量生理盐水.于术前1d、术后3、7、14 d(T0-3)时测定大鼠机械缩足阈值(MWT)和热缩爪潜伏期(TWL);于T1-3时测定痛阈后每组随机处死8只大鼠,取L4,5脊髓组织,采用免疫组化法检测脊髓背角Bcl-2及caspase-3的表达水平,采用透射电镜观察脊髓背角浅层神经元超微结构.结果 与S组比较,CNP组和D组T1-3时MWT降低,TWL缩短,脊髓背角Bcl-2和caspase-3表达上调(P＜0.05);与CNP组比较,D组T1 -3时MWT升高,TWL延长,脊髓背角Bcl-2表达上调,caspase-3表达下调(P＜0.05).脊髓背角浅层神经元超微结构:S组基本正常,CNP组细胞凋亡数目增加,D组细胞凋亡数目较CNP组减少.结论 腹腔注射右美托咪啶可减轻大鼠慢性神经病理性痛,其机制可能与抑制脊髓背角神经元凋亡有关.     

脊髓背角HDAC6在右美托咪定减轻大鼠神经病理性痛中的作用

目的评价脊髓背角组蛋白去乙酰化酶6(HDAC6)在右美托咪定减轻大鼠神经病理性痛中的作用。方法清洁级健康雄性SD大鼠40只, 7～9周龄, 体重190～240 g, 采用随机数字表法分为5组(n=8):对照组(C组)正常饲养, 不作任何处理;假手术组(SH组)分离坐骨神经但不结扎;神经病理性痛组(NP组)采用坐骨神经慢性压迫损伤(CCI)的方法制备大鼠神经病理性痛模型;右美托咪定组(D组)CCI后每天腹腔注射右美托咪定40 μg/kg;HDAC6抑制剂ACY-1215+右美托咪定组(AD组)CCI前即刻每天腹腔注射ACY-1215 25 mg/kg, CCI后腹腔注射右美托咪定40 μg/kg, 直至CCI后15 d;S组和NP组腹腔注射等体积溶剂。于CCI前1 d(T0)、CCI后3 d(T1)、6 d(T2)、9 d(T3)、12 d(T4)和15 d(T5)时测定机械缩足反应阈(MWT)和热缩足潜伏期(TWL), 随后处死大鼠取L4-6脊髓背角组织, 采用Western blot法检测髓样分化因子88(MyD88)和NF-κB p65的表达。结果与C组和SH组比较, NP组、D组...     

氯胺酮与可乐定对神经病理性痛大鼠脊髓P2X4R mRNA表达的影响

目的 评价氯胺酮与可乐定对神经病理性痛大鼠脊髓P2X4受体mRNA(P2X4R mRNA)表达的影响.方法 雄性SD大鼠80只,体重180～220 g,随机分为假手术组(S组)、神经病理性痛组(NP组)、氯胺酮组(K组)、可乐定组(CL组)和氯胺酮+可乐定组(KC组),每组16只.采用坐骨神经慢性压迫(CCI)法制备大鼠神经病理性痛模型.K组、CL组、KC组于CCI后3～21 d每天分别腹腔注射氯胺酮10 mg/kg、可乐定1 mg/kg和氯胺酮5 mg/kg+可乐定0.5 mg/kg.S组和NP组腹腔注射等容量生理盐水.分别于CCI前1 d、CCI后3、7、14和21 d且腹腔注射前,随机取4只大鼠,测定机械痛阈和热痛阈,并于CCI前1 d、CCI后7、14和21 d痛阈测定结束后断头处死,测定脊髓P2X4R mRNA表达水平.结果 与CCI前1 d比较,CCI后S组热痛阈、机械痛阈和脊髓P2X4R mRNA表达差异无统计学意义(P>0.05),其余4组热痛阈和机械痛阈降低,脊髓P2X4R mRNA表达上调(P<0.05);与NP组比较,K组、CL组、KC组CCI后热痛阈及机械痛阈升高,脊髓P2X4R mRNA表达下调(P<0.05);与K组比较,KC组CCI后热痛阈和机械痛阈升高,脊髓P2X4R mRNA表达下调(P<0.05),CL组上述指标差异无统计学意义(P>0.05).结论 氯胺酮与可乐定减轻大鼠神经病理性痛的机制可能与下调脊髓P2X4R mRNA的表达有关.     

鞘内注射舒芬太尼对神经病理性痛大鼠脊髓背角NMDA受体及CGRP表达的影响

目的 评价鞘内注射舒芬太尼对神经病理性痛大鼠脊髓背角N-甲基-D-天冬氨酸(NMDA)受体及降钙素相关基因肽(CGRP)表达的影响.方法 雄性SD大鼠36只,体重220～280 g,随机分为4组(n=9):正常对照组(C组)、假手术组(S组)、坐骨神经分支选择性损伤组(SNI组)和舒芬太尼+坐骨神经分支选择性损伤组(S+SNI组).SNI组和S+SNI组制备SNI模型,S+SNI组在SNI术后14 d内每天鞘内注射舒芬太尼1 μg(用生理盐水稀释至10 μl),其余各组给予等容量生理盐水.于SNI给药前2 d(基础状态)及给药1、2、7、14 d测定机械痛阈和热缩足潜伏期,分别于给药2、7、14 d测定痛阈后立即处死3只大鼠,采用免疫组化法测定L5节段脊髓背角NMDA受体和CGRP表达水平.结果 与C组和S组比较,SNI组机械痛阚降低,NMDA受体和CGRP表达上调(P<0.01),热缩足潜伏期差异无统计学意义(P>0.05).与SNI组比较,S+SNI组机械痛阈升高,热缩足潜伏期延长,NMDA受体和CGRP表达下调(P<0.01).结论 鞘内注射舒芬太尼可抑制脊髓背角NMDA受体和CGRP表达上调,从而减轻大鼠神经病理性痛.     

右美托咪啶对神经病理性痛大鼠脊髓嘌呤受体P2X4mRNA和p38丝裂原活化蛋白激酶mRNA表达的影响

目的 评价右美托咪啶对神经病理性痛大鼠脊髓嘌呤受体P2X4(P2XR)mRNA和p38丝裂原活化蛋白激酶(p38 MAPK)mRNA表达的影响.方法 雄性SD大鼠72只,体重180～220 g,采用随机数字表法,将大鼠随机分为3组(n=24):假手术组(S组)、神经病理性痛组(NP组)和右美托咪啶组( DEX组).采用坐骨神经慢性压迫性损伤法建立神经病理性痛模型.DEX组于术后即刻开始每天腹腔注射右美托咪啶50 μg/kg,S组和NP组腹腔注射等容量生理盐水.于术前1d、术后1、3、7和14 d时测定机械痛阈(MWT)和热痛阈(TWL).术后测定痛阈后随机取6只大鼠,断头处死,取损伤侧L4～6脊髓组织,采用RT-PCR法测定P2X4R mRNA和p38 MAPK mRNA表达.结果 与S组比较,NP组和DEX组术后MWT及TWL降低,脊髓P2X4R mRNA和p38 MAPK mRNA表达上调(P＜0.05).与NP组比较,DE组术后MWT及TWL升高,脊髓P2X4R mRNA和p38 MAPK mRNA表达下调(P＜0.05).与术后7d时比较,NP组和DEX组于术后1、3、14 d时MWT和TWL升高,P2X4R mRNA和p38MAPK mRNA表达下调(P＜0.05).结论 右美托咪啶减轻大鼠神经病理性痛的机制与抑制P2X4RmRNA和p38 MAPK mRNA的表达有关.     

鞘内注射右美托咪定对坐骨神经结扎损伤模型大鼠的镇痛作用

目的观察鞘内注射右美托咪定对坐骨神经结扎损伤(CCI)模型大鼠的镇痛作用。方法雄性SD大鼠36只,随机均分为假手术组(S组)、手术对照组(C组)和右美托咪定组(D组)。于CCI前、鞘内给药前和鞘内给药后1、2、3、4、5d时采用BME-410A型热痛刺激仪和37400-002型接触刺激仪,分别测定大鼠热刺激缩足反射潜伏期(TWL)和机械刺激缩足反射痛阈值(MWT)。于鞘内给药5d后取脊髓L4～L5节段,采用免疫组织化学法观察脊髓背角FLI-N(c-fos免疫阳性反应神经元)数目。结果与S组比较,给药前、给药后各时点C组和D组TWL和MET均明显降低(P<0.05);与C组比较,给药后各时点D组TWL延长和MWT均明显升高(P<0.05);与S组比较,C组脊髓背角FLI-N明显增多(P<0.05),与C组比较,D组脊髓背角FLI-N明显减少(P<0.05)。结论鞘内注射右美托咪定可减轻CCI引起的痛敏,可能与其抑制脊髓背角c-fos蛋白表达有关。     

氯胺酮对CCI大鼠背根神经节GAP-43 mRNA表达的影响

目的 观察氯胺酮对坐骨神经慢性压迫损伤(CCI)模型大鼠背根神经节(DRG)生长相关蛋白(GAP-43) mRNA表达的影响.方法 36只成年雄性SD大鼠.体重180～220g,随机均分为三组.氯胺酮组(K组)和CCI组(C组)均采用CCI模型,假手术组(S组)仅暴露坐骨神经,不结扎.K组大鼠于CCI后3～14d每天腹腔注射氯胺酮10mg/kg,C组和S组腹腔注射等容量生理盐水.在术前(To)、术后3d(T1)、7d(T2)、14d(T3)时测定机械痛阈和热痛阈值;T1～T3时测定痛阈后,每组随机取4只大鼠取腰段脊髓背根神经节(DRG)检测GAP-43 mRNA的水平.结果 与S组比较,K组和C组术后机械痛阈和热痛阈降低,GAP-43 mRNA表达升高(P<0.05);与NP组比较,T2、T3时K组机械痛阈和热痛阈升高,GAP-43 mRNA表达降低(P<0.05).结论 腹腔注射氯胺酮10mg/kg可减轻CCI大鼠疼痛,其机制可能与抑制DRG中GAP-43 mRNA表达升高有关.     

脊髓谷氨酸转运体、孤啡肽和脑源性神经营养因子在炎性痛大鼠吗啡耐受形成中的作用

目的 探讨脊髓谷氨酸转运体(GT)、孤啡肽(OFQ)和脑源性神经营养因子(BDNF)在炎性痛大鼠吗啡耐受形成中的作用.方法 健康雄性SD大鼠,8～ 10周龄,体重300 ～ 350 g,取鞘内置管成功的雄性SD大鼠20只,采用随机数字表法,将其随机分为4组(n=5):生理盐水组(NS组)、炎性痛组(IP组)、吗啡组(M组)和GT激动剂riluzole组(R组).NS组于左后足踝关节腔注射生理盐水50μl,其余3组注射完全弗氏佐剂50 μl.3d后,NS组和IP组鞘内注射生理盐水10 μl;M组鞘内注射吗啡10 μg;R组鞘内注射riluzole 10 μg,30 min后注射吗啡10 μg.注射药物容量均为10μl,2次/d,连续7d.于鞘内给药前、鞘内给药2、4、6d和鞘内给药结束后1 d(T0-4)时测定机械痛阈.于T4时痛阈测定后取左侧脊髓背角,采用RT-PCR法测定OFQ mRNA和BDNF mRNA的表达.结果 与NS组比较,IP组机械痛阈降低,脊髓背角OFQ mRNA及BDNF mRNA表达上调(P＜0.05或0.01);与IP组比较,M组T1,2时机械痛阈升高,脊髓背角OFQ mRNA及BDNF mRNA表达上调(P＜0.05或0.01),T3,4时机械痛阈差异无统计学意义(P＞0.05);与M组比较,R组机械痛阈升高,脊髓背角OFQ mRNA及BDNF mRNA表达下调(P＜0.05或0.01).结论 炎性痛大鼠长期注射吗啡时脊髓GT功能降低,导致谷氨酸水平升高和OFQ、BDNF表达上调之间的失衡,可能在吗啡耐受形成中起到一定作用.     

右美托咪定预处理对大鼠心肌缺血-再灌注后心室功能和细胞凋亡的影响

目的探讨右美托咪定预处理对大鼠心肌缺血-再灌注损伤后心室功能和心肌细胞凋亡的影响。方法 30只SD大鼠随机分为三组,右美托咪定组(D组),右美托咪定+育亨宾组(D+Y组)和对照组(IR组),D组给予右美托咪定5μg·kg-1·h-1预处理1h,D+Y组静脉注射育亨宾1mg/kg,10min后按5μg·kg-1·h-1输注右美托咪定1h;IR组仅输注等量生理盐水,建立Langendorff缺血-再灌注模型,每10分钟测定左心室舒张末压(LVEDP)、左心室收缩压(LVSP)、左心室内压最大上升速率、下降速率(±dp/dtmax),计算左心室发展压(LVDP)。60min后取下心脏并以TUNEL检测心肌细胞的凋亡,RT-PCR检测Bcl-2mRNA,Bax mRNA的表达。结果与D组比较,再灌注后不同时点IR组和D+Y组大鼠LVDP、±dp/dtmax、Bcl-2mRNA表达明显降低、LVEDP、Bax mRNA表达明显升高(P0.05)。IR组和D+Y组LVDP、LVEDP、±dp/dtmax、Bcl-2mRNA和Bax mRNA表达差异均无统计学意义。IR组细胞阳性率为(36.1±9.2)%、D+Y组为(38.2±6.5)%,明显高于D组为(24.0±8.3)%(P0.05),而IR组和D+Y组细胞阳性率差异无统计学意义。结论右美托咪定预处理可以显著改善大鼠心肌缺血-再灌注损伤后的心室功能,并且可能通过调控凋亡基因Bcl-2mRNA和促凋亡基因BaxmRNA的表达,减少心肌细胞凋亡。     

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.