合并胸腰段后凸的青少年特发性脊柱侧凸的临床研究

目的 探讨合并胸腰段后凸的青少年特发性脊柱侧凸(AIS)的临床特点和手术治疗策略. 方法对2001年1月至2007年1月收治的413例AIS患者进行回顾性分析,合并胸腰段后凸者共10例,其中男2例,女8例;年龄12～18岁,平均14.3岁.侧凸类型包括PUMC Ⅱb2型3例,Ⅱc 3型4例,Ⅱd2型1例,Ⅲb型2例.单纯后路内固定术8例,前路松解+后路内固定术2例.术前、术后及随访时摄X线片,对侧凸类型、Cobb角、顶椎旋转度、顶椎偏距、侧凸柔韧性、胸腰段后凸、冠状面及矢状面躯干偏移进行评测和分析.结果 本组患者中双弯8例,三弯2例;胸腰弯/腰弯Cobb角≥45°者7例,柔韧性指数≤70%者6例,顶椎旋转度≥Ⅱ度者9例.所有病例的融合范围均符合PUMC分型原则.手术前后平均胸弯冠状面Cobb角分别为71.7°和37.4°,平均矫正率为47.8%;手术前后平均胸腰弯/腰弯冠状面Cobb角分别为65.0°和27.8°,平均矫正率为57.2%;手术前后平均胸腰段后凸分别为35.5°和4.2°,平均矫正率为88.2%.全部病例随访12～72个月,平均23.1个月;最终随访时无躯干失平衡发生. 结论 合并胸腰段后凸的AIS一般多为双弯或三弯,胸腰弯/腰弯畸形往往比较严重,并有明显的旋转畸形.对合并胸腰段后凸的AIS,应融合胸腰弯/腰弯以防止术后发生失代偿或后凸加重, PUMC分型可以有效识别病变类型并指导融合范围的选择.     

青少年特发性脊柱侧凸的选择性胸椎融合治疗

目的　探讨青少年特发性脊柱侧凸选择性胸椎融合治疗的适应证。方法　回顾性分析12例行选择性胸椎融合患者术前、术后及随访时的X光像 ,对侧凸类型、侧凸Cobb角、顶椎旋转度、顶椎偏距、侧凸柔韧性、躯干偏移及胸腰段矢状面Cobb角进行测量和分析。患者 12例中男 2例 ,女10例 ,平均年龄 15 1(13～ 18)岁。侧凸均为KingⅡ型 ,其中PUMCⅡb1型 9例 ,Ⅱc3型 3例。所有病例均行选择性胸椎融合 ,平均随访 3 5 (1～ 10 5 )年。结果　手术前后胸弯冠状面Cobb角分别为5 4 0°、19 0° ,平均矫正率 6 2 7% ;腰弯冠状面Cobb角分别为 34 6°、12 5° ,自动矫正率为 6 4 7%。最后随访时 ,胸、腰弯的冠状面Cobb角分别为 18 8°、15 9°;腰弯冠状面Cobb角、顶椎偏距及顶椎旋转度与术后相比无显著变化。术后发生胸腰段后凸 1例 ,最终随访时未见进一步加重。无躯干失平衡现象发生。选择性胸椎融合较后路融合双弯平均减少 3 5个融合节段。结论　对腰弯柔韧性好且度数较小的KingⅡ (PUMCⅡb1和部分Ⅱc3)型特发性脊柱侧凸 ,可安全有效地行选择性胸椎融合     

胸腰段特发性脊柱侧凸的前路矫正术

目的评价胸腰段/腰段特发性脊柱侧凸经前路矫正术的临床效果。方法1998年1月~2004年1月,76例胸腰段/腰段特发性脊柱侧凸患者接受前路选择性矫正融合术。患者共76例,男19例,女57例,平均年龄为16.2岁(13~27岁)。按照Lenke分型,Ⅴ型41例,Ⅵ型35例。其中Lenke Ⅴ型术前胸腰段侧凸Cobb角平均51.3°(38°~65°),胸段侧凸Cobb角平均35.5°(23°~41°);Lenke Ⅵ型术前胸腰段侧凸Cobb角平均53.4°(46°~68°),胸段侧凸Cobb角平均39.2°(27°~51°)。所有患者均接受侧前路矫正选择性胸腰段融合。术后以及随访中对胸腰段侧凸矫正以及胸段代偿矫正情况进行分析对比,同时采用SRS-22评分评价患者手术前后的功能状况。结果患者均安全完成手术,无严重并发症发生。所有患者均随访2年以上(2~5年)。Lenke Ⅴ型组术后胸腰段侧凸Cobb角平均11.2°(3°~15°),胸段侧凸Cobb角平均8.3°(2°~11°),最终随访时分别为13.2°(5°~17°)和10.1°(4°~15°),无躯干冠状面失代偿发生;LenkeⅥ型组术后Cobb角平均16.3°(8°~21°),胸段侧凸Cobb角平均13.7°(11°~19°),最终随访时分别为17.5°(11°~24°)和15.2°(14°~21°);仅1例发生躯干冠状面失代偿,但不需要进一步治疗。两组之间无统计学差异。所有患者均在术后以及最终随访时填写了SRS-22评分表,结果显示两组患者均对治疗结果表示满意。结论胸腰段/腰段特发性脊柱侧凸经前路矫正、选择性融合可以获得良好矫正,术后胸段弯曲能够获得较好的代偿矫正,并在远期随访中维持矫正效果和躯干冠状面的平衡。     

King Ⅱ型特发性脊柱侧凸的手术治疗

目的:探讨KingⅡ型特发性脊柱侧凸的手术治疗效果。方法:将37例KingⅡ型脊柱侧凸分为两组,A组12例为KingⅡA型,行选择性胸椎融合;B组25例为KingⅡB型,行胸腰弯融合。手术均采用中华长城系统经后路矫形固定。结果:随访24～50个月,A组胸弯平均矫正率79.1%,腰弯矫正率71.4%,有2例发生躯干失平衡;B组胸弯平均矫正率70.8%,腰弯矫正率73.5%,1例发生躯干失平衡。结论:KingⅡA型行选择性胸弯融合,KingⅡB型融合胸腰弯,可获得良好的临床效果。     

选择性胸椎融合治疗PUMC Ⅱ型青少年特发性脊柱侧凸

目的 评价选择性胸椎融合治疗PUMC Ⅱ型特发性脊柱侧凸(IS)的效果.方法 回顾性分析术后随访时间超过1年且影像学资料完整的PUMC Ⅱ型IS 25例,男2例,女23例;年龄11～18岁,平均14.3岁.术前、术后及随访时摄X线片,对侧凸类型、侧凸Cobb角、顶椎旋转度、顶椎偏距、侧凸柔韧性、胸腰段后凸、躯干偏移进行测量和分析.侧凸类型包括Ⅱb1型20例,ⅡC3型5例.其中前路矫形4例,后路矫形21例.结果 手术前后胸弯冠状面Cobb角分别为48.0°和14.3°,平均矫正率为70.0%;手术前后腰弯冠状面Cobb角分别为32.2°和11.9°,自动矫正率为62.9%,最终随访时无躯干失平衡发生.全部病例随访12～58月,平均17.4个月.结论 参照PUMC分型的融合范围选择原则,采用选择性胸椎融合治PUMC Ⅱ b1型和部分PUMCⅡC3型IS,可以保留更多脊柱活动度,同时冠状面和矢状面矫形效果满意,无术后失代偿.     

全节段椎弓根螺钉后路选择性融合胸弯或腰弯后代偿弯的自发性矫形比较

目的 比较后路选择性融合胸弯或胸腰弯/腰弯矫正青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)后代偿弯的自发性矫形.方法 回顾性分析随访2年以上的双弯型AIS患者共41例(男6例,女35例),手术时平均年龄为13.8(11～16)岁,随访时间平均29(24～36)个月.北京协和医学院(Peking Union Medical College Hospital,PUMC)分型Ⅱb1型13例,Ⅱc1型5例,Ⅱc3型7例,Ⅱd1型16例.分为选择性胸弯融合(STF)组21例和选择性胸腰弯/腰弯融合组(SLF)20例.术前、术后和随访2年时摄站立位全脊柱正侧位和术前仰卧位左右弯曲像.结果 STF组和SLF组融合节段分别为(9.1±0.9)个和(5.5±0.7)个;术前和术后随访2年以上躯干偏移(TS)在STF组分别为(14.8±7.8)mm和(11.4±5.9)mm(P=0.048);SLF组为(24.7±7.3)mm和(13.2±4.9)am(P＜0.001);STF组代偿性腰弯由37.7°±6.8°自发矫形为15.1°±8.4°(P=0.001);SLF组代偿性胸弯由27.4°±6.7°自发矫形为14.9°±5.0°(P＜0.001).术前和术后2年在STF组中胸后凸由18.0°±6.8°降至13.5°±7.6°(P＜0.01),腰前凸由37.9°±8.4°增至43.8°±6.8°(P＜0.05);SLF组中胸后凸由12.8°±7.8°增至28.4°±10.8°(P＜0.001),腰前凸由33.4°±8.8°增至39.6°±6.9°(P＜0.05).两组术前与术后即刻、术后2年腰弯Lenke分型差异有统计学意义(P＜0.001).结论 后路全节段椎弓根螺钉系统选择性融合胸弯或胸腰弯/腰弯矫正AIS代偿弯在冠状面、矢状面上自发性矫形程度不同,腰弯Lenke分型在两组中变化明显.     

特发性胸椎侧凸上胸弯的认定及其临床意义

naqqaaq特发性胸椎侧凸（King Ⅴ型、Lenke 2型）中的上胸弯问题是一个历史命题。早在1950年Ponseti就认识到上胸弯的存在。并将其分型为颈胸弯。Harrington时代由于对脊柱侧凸矫形能力有了很大提高，King发现特发性胸椎侧凸患者出现上胸弯时仅矫形固定下胸弯会导致术后双肩畸形加重。他认为这是由于下胸弯过度纠正超过上胸弯代偿能力所致的一种失代偿现象。     

特发性脊柱侧凸PUMC分型的可重复性及可信度研究

目的:探讨特发性脊柱侧凸PUMC(协和)分型系统的一致性,并对影响分型一致性的因素进行分析.方法:随机选取南京鼓楼医院2004年～2006年治疗的80例特发性脊柱侧凸患者,其中男性15例,女性65例,平均年龄14.6岁(10～18岁),均有完整的术前站立位正侧位X线片及仰卧位左右Bending片共四张.由4名脊柱外科专科医生分别根据PUMC(协和)分型标准进行分型,2周后此4位医生分别对这些患者的X线片再次进行分型,收集分型结果分别作可信度和可重复性分析,计算Kappa值检验一致性并对影响分型一致性的因素进行统计分析,结果:80例患者均可用PUMC分型,分型可信度平均Kappa值为0.801,可重复性Kappa值为0.878.PUMC分型不一致中包括上胸弯的界定18次;胸弯明显时,代偿性与结构性腰弯的界定15次;腰弯明显时,代偿性与结构性胸弯的界定18次;单弯顶点的判断20次;测量角度的差异18次.结论:PUMC(协和)分型学习曲线相对较短,易于掌握且具有良好的可信度和可重复性.     

King Ⅱ型特发性脊柱侧凸的手术治疗

目的：探讨King Ⅱ型特发性脊柱侧凸患者三维矫形融合节段的选择。方法：1997年7月～2002年6月手术矫形治疗King Ⅱ型特发性脊柱侧凸患者79例，平均年龄14．3岁，其中King Ⅱ A型28例，均行选择性胸椎融合，平均融合椎体8．5个；King ⅡB型51例，均固定融合胸椎与腰椎，平均融合椎体11．8个。结果：术后平均随访35个月(12～57个月)，King ⅡA型胸弯矫正率为56％，King ⅡB型的胸弯矫正率为67％，腰弯矫正率为60％。共有5例躯干失平衡并发症，其余患者均获得较好的躯干平衡和矫形效果。结论：KingII型特发性脊柱侧凸进行选择性胸椎融合是可行的，但应慎重。     

青少年特发性脊柱侧凸King、Lenke和PUMC(协和)分型的可信度和可重复性比较及意义

目的比较青少年特发性脊柱侧凸King、Lenke和PuMC（协和）分型系统的可信度和可重复性，探讨PUMC（协和）分型的临床应用价值。方法随机选取2002年1月至2004年12月手术治疗的100例青少年特发性脊柱侧凸病例，男22例，女78例；年龄1肌18岁，平均14．9岁。主弯Cobb角40°-75°，平均52°每例患者均有完整的术前X线片资料，包括术前站立位全脊柱正侧位及仰卧位左右Bending片和骨盆X线片，X线片均不进行预先测量。由4名有分型经验的脊柱外科医生分别进行脊柱侧凸的King、Lenke和PUMC（协和）分型，2周后再次进行分型，收集结果后对分型的可信度和可重复性进行分析。计算Kappa检验的一致性。结果King、Lenke、PUMC（协和）分型的可信度平均为81．2％（Kappa值=0．773）、60．5％（Kappa值=0。560）、8413％（Kappa值=0．819），可重复性平均为91．5％（Kappa值=0．897）、81．8％（Kappa值=0．796）、92％（Kappa值=0．907）。结论PUMC（协和）分型包括了脊柱侧凸在三平面内的畸形特点，分型全面，易于掌握，而且具有很好的可信度和可重复性，适合脊柱侧凸的三维矫形。     

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.     

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.

     

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.     

足踝损伤的分类与治疗的要点和难点

足踝部损伤主要有踝关节骨折脱位、距骨骨折脱位、跟骨骨折以及跖骨骨折、趾骨骨折、跖趾关节脱位、踝关节周围软组织损伤等。足踝损伤防治的重点是踝关节骨折脱位、距骨骨折脱位、跟骨骨折以及踝关节周围软组织损伤。本文针对足踝损伤的要点和难点分类进行阐述。1踝关节骨折目前踝关节骨折的分类主要有:Ashhurst分类法[1]、Lauge-Hanson分类法[2]、Danis-Weber分类法[3]。Ashhurst分类法按照外力的性质分类,然后按单踝、双踝、三踝骨折分级,优点是简单易记,对认识外力的性质很有帮助,缺点是没有考虑到外伤时的体位、姿势等复合因素;Laug…     

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.     

Selective role of vagal and nonvagal innervation in initiation and coordination of gastric and small bowel patterns of interdigestive and postprandial motility

Our previous studies suggested that extrinsic innervation modulates upper gut motility but is not requisite for cyclic interdigestive and postprandial motility of the stomach. However, the specific role of vagal and nonvagal extrinsic innervation in the initiation, coordination, and pattern of gastric motility in dogs after denervation of the entire upper gastrointestinal tract remains unclear. The aim of this study was to determine the role of vagal and nonvagal extrinsic innervation in control of gastric motility patterns. Mongrel dogs were subjected first to extrinsic denervation (in situ neural isolation) of the stomach, small bowel, proximal colon, liver, and pancreas but specifically maintaining vagal innervation to the stomach alone. After fasting and fed motility patterns were measured with indwelling gastric and small bowel manometry catheters, the dogs underwent transtboracic truncal vagotomy (completion of total extrinsic denervation of stomach), and motility studies were repeated. Vagal integrity to the stomach and pancreas was confirmed by means of a modified Hollander test and serum pancreatic polypeptide concentrations after the injection of exogenous insulin, respectively. We found that a cyclic motility pattern (migrating motor complex) persisted during fasting in both the stomach and the small bowel and that the patterns of tbe stomach and the duodenum remained temporally coordinated before and after vagotomy. However, although a cyclic phase III activity persisted in the stomach after vagotomy, the number of contractions and the motility index during phase III were decreased, and the duration between groupings of contractions was increased. No differences were noted in the duration of postprandial inhibition after feeding meals before and after vagotomy. These observations support our hypothesis that the vagal nerves are not necessary for the initiation or temporal coordination of global fasting or postprandial gastroduodenal motility patterns but are involved in modulating the pattern of contractions during gastric phase III. Supported in part by United States Public Health Service grant DK 39337 from the National Institutes of Health (M.G.S.) and by the Mayo Foundation. Presented at the Forty-First Annual Meeting of The Society for Surgery of the Alimentary Tract, San Diego, Calif., May 21–24, 2000 (Poster presentation), and published as an abstract in Gustroenterology 118:Al0S0, 2000.     

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.