绝经后骨质疏松妇女血清相关激素水平的改变

目的　通过分析绝经后骨质疏松妇女某些骨代谢相关激素的血清水平的改变 ,探讨其与绝经后骨质疏松的关系。方法　 6 2名绝经 2年以上妇女 ,测量腰椎骨密度 ,分为骨质疏松组 (30名 )和对照组 (32名 )。隔夜空腹取血测定血清LH、FSH、E1、E2 、DHEA、DHEA S、SHBG、GH、CT、PTH、2 5 (OH)D3 。结果　绝经后妇女骨质疏松组和对照组在年龄上无差异 (5 9 5 6± 6 6 5vs 5 9 35± 7 6 3,P>0 0 5 )。骨质疏松组体重指数BMI (2 4 2 7± 2 4 6 )低于对照组 (2 6 83± 4 16 ,P <0 0 5 )。绝经后妇女血清E1(r= 0 6 0 0 ,P <0 0 0 1)、DHEA(r= 0 70 8,P <0 0 0 1)、DHEAS(r = 0 5 82 ,P <0 0 0 1)与年龄负相关。骨密度与LH负相关 (r= 0 4 39,P <0 0 5 )。骨质疏松组与对照组相比 ,LH、SHBG显著增高 (P<0 0 5 ) ,DHEA、DHEAS显著降低 (P <0 0 5 )。FSH、CT、PTH、2 5 (OH)D3 、GH、E1、E2 差异无显著性。结论　绝经后妇女骨代谢相关激素血清水平的改变参与了绝经后骨质疏松的发病     

成年女性年龄相关的促卵泡刺激素和促黄体生成素水平与骨密度关系

目的调查女性年龄相关的血清促卵泡刺激素(FSH)和促黄体生成素(LH)水平及其与骨密度的关系。方法测定699例受试者血清FSH和LH浓度及正位腰椎(AP)、侧位腰椎(LP)、总髋部(T-hip)、远端前臂(DF)骨密度,评价血清FSH和LH与年龄、骨密度的关系。结果FSH和LH从40岁起随增龄而增加,至≥60岁随增龄而下降。绝经前血清FSH和LH的几何平均值(SD)分别为3.94±2.08IU/L和7.51±2.58IU/L,绝经后分别为28.8±1.88IU/L和25.6±1.95IU/L。血清FSH与LH呈高度正相关(r=0.734,P=0.000)。FSH和LH与各部位骨密度呈显著负相关,FSH与骨密度的相关程度(r=-0.597～-0.492)好于LH与骨密度(r=-0.332～-0.452)的相关程度。其中FSH(r=-0.597)和LH(r=-0.452)与腰椎骨密度的负相关性最好。结论成年女性血清FSH和LH随年龄和绝经状态而变化,FSH和LH与骨密度明显相关。血清FSH和LH增加的妇女骨密度下降。     

绝经后妇女血清催乳素水平与骨代谢指标及骨密度相关性研究

目的评价绝经后妇女血清催乳素水平与骨代谢指标及骨密度相关性。方法 161名健康的绝经后妇女参加了该横断面研究。获得空腹静脉血样用于骨代谢指标和激素水平的评估。人体测量参数包括体重指数(BMI)和腰臀比(WHR)。使用DXA检测股骨颈(FN)和腰椎(LS)部位的BMD。结果本研究共纳入161名绝经后妇女,平均年龄(59.7±6.1)岁,平均绝经时间为(8.0±1.3)岁,血清催乳素为(54.98±6.15)μg/L; Spearman相关分析卵巢体积与年龄、YSM、FSH、PTH、LH、OC和CTX呈正相关; BMI、LS BMD、FN BMD、雌二醇、睾酮和25羟基维生素D呈负相关,与其他混杂因素无关。多元回归分析表明年龄、BMI、YSM、LS BMD、FN BMD、FSH、LH、雌二醇、OC和CTX是绝经后妇女催乳素升高的独立预测因子。结论绝经后妇女催乳素升高和雌激素水平降低、骨密度下降和骨转换加速密切相关。     

铁过载对绝经后骨质疏松患者骨密度和骨代谢的影响

目的 观察铁过载对绝经后骨质疏松患者骨密度和骨代谢的影响。方法 将234名绝经后妇女按照骨密度（bone mineral density, BMD）分为正常组、骨量减少组和骨质疏松组。分析铁过载对年龄、绝经年数、血钙(Ca)、磷(P)、体质量指数（bone mass index,BMI）、肝肾功能、葡萄糖代谢、脂质代谢、炎症反应、BMD、抗酒石酸酸性磷酸酶5b(TRACP-5b)、ALP、Ⅰ型胶原交联C端肽(β-CTX)和Ⅰ型胶原交联N端肽(PINP)的影响。结果 与正常组相比,骨量减少组和骨质疏松组血清铁蛋白(Fer)显著升高(P<0.05)。Fer水平与BMD呈负相关(P<0.05)。TRACP-5b水平在骨质疏松组明显高于正常组(P<0.05)。与正常组相比,骨质疏松症组的ALP水平显著升高(P<0.05)。与骨量减少组相比,骨质疏松组血清β-CTX水平明显升高(P<0.05);且骨质疏松组的PINP水平显著高于正常组(P<0.05)。更重要的是,血清Fer和PINP之间存在正相关(P<0.05);血清Fer和β-CTX之间呈正相关(P<0.05)。结论 铁过载对绝经后骨质疏松患者骨密度和骨代谢均有显著影响。     

不同年龄段孕前保健妇女抗苗勒氏管激素与性激素水平分析

目的探讨不同年龄段孕前保健妇女血清抗苗勒氏管激素(AMH)和性激素水平的差异。方法收集2016年3月至2017年2月在西安长安医院妇产科进行孕前保健检查的785例育龄妇女的资料,按年龄分为3组:26~30岁组、31~35岁组和36~40岁组。采用酶联免疫吸附法检测AMH水平,化学发光法测定血清LH、FSH、E_2、T、P和PRL水平,分析检测结果。结果随年龄增加,AMH水平逐渐降低,AMH1.1ng/ml的发生率逐渐提高,3组两两比较差异均有统计学意义(P0.05);FSH和LH水平随年龄增加也逐渐升高,36~40岁组的FSH升高更为显著,其基础FSH/LH≥2的比例显著大于其它两组(P0.05);3组间E_2、P、T和PRL水平的差异均无统计学意义(P0.05)。结论不同年龄段育龄女性血清AMH水平和基础FSH/LH比值存在显著差异,对35岁以上人群进行AMH和性激素筛查对于卵巢的储备功能有较好的预测价值。     

绝经后骨质疏松症女性血清IL-31和腰椎、股骨颈骨密度相关性研究

目的探索绝经后骨质疏松症(postmenopausal osteoporosis,PMOP)患者血清白介素31(IL-31)水平与骨密度(bone mineral density,BMD)相关性。方法采用双能X线吸收法对80例OP患者(50~75岁)和90例健康对照者(50~75岁)进行腰椎和股骨颈BMD检测。血清IL-31、BAP、BGP和TRACP-5b水平通过酶联免疫吸附法检测。使用自动电化学发光系统测量血清I型胶原交联N-末端肽(NTX-1)和25-羟基维生素D[25(OH)D]水平。结果OP妇女的IL-31水平明显高于健康对照组[(45.12±6.65)μg/L vs(27.58±5.09)μg/L,P=0.002]。绝经后骨质疏松患者血清IL-31水平与年龄、BMI、BAP、BGP、TRACP-5b、NTX和25(OH)D呈正相关。腰椎和股骨颈骨密度与年龄、IL-31、BAP、TRACP-5b和NTX之间有显著的负相关。在偏相关分析中调整年龄和BMI后,IL-31和腰椎和股骨颈骨密度之间存在显著负相关。结论绝经后骨质疏松症患者血清IL-31水平升高,与BMD呈负相关。     

甲状旁腺激素(1-34)联合伊班膦酸钠治疗严重骨质疏松症的临床研究

目的甲状旁腺激素(parathyroid hormone,PTH)(1-34)联合伊班膦酸钠治疗严重骨质疏松症效果临床观察。方法98例严重绝经后骨质疏松症合并骨骼疼痛患者随机分为治疗组和对照组,治疗组使用PTH联合伊班膦酸钠治疗,对照组单纯予以伊班膦酸钠治疗,为期12个月。分别检测两组受试者腰椎及髋部骨密度、血清骨代谢指标治疗前后的改变。结果药物治疗6个月后两组患者腰椎L1~4及股骨粗隆、左侧股骨颈、Ward三角区的骨密度明显增加,且12个月后骨密度进一步增加,显著高于对照组(P0.05);药物治疗12个月后两组血清及碱性磷酸酶(ALP)、血清Ⅰ型胶原C末端肽(s-CTX)、血清抗酒石酸酸性磷酸酶-5b(TRACP-5b)、血清骨源性碱性磷酸酶(BAP)及血清骨钙素(OC)水平均显著改变,且治疗组对ALP及s-CTX、BAP、OC及TRACP-5b影响更明显(P0.05),而两组血钙(Ca)及血磷(P)治疗前后无明显差异(P0.05)。结论PTH联合伊班膦酸钠使用能有效提高严重骨质疏松症患者髋部及腰椎骨密度,改善骨代谢。     

哈萨克族女性绝经后骨代谢水平及生活方式的研究

目的 探讨绝经后哈萨克族族女性骨代谢水平及生活方式的特点.方法 选择符合研究对象的208名绝经后哈萨克族女性,测BMD、Ca、P、BAP、BGP、TRACP-5b、25-(OH)D3,按BMD值分为正常组,骨量减少组和骨质疏松组并进行比较.结果 经单因素方差分析,各组中各自BGP、BAP、TRACP-5b、25-(OH)D3中有统计学意义(P＜0.01),骨代谢水平与哈萨克族生活方式有关.结论 骨代谢水平在哈萨克族绝经妇女中差异反应出绝经后妇女与生活方式、膳食结构有关,维生素D代谢上可能存在基因多态性影响.     

性激素及甲状旁腺激素与老年男性骨转换生化指标的相关性分析

目的:探讨老年男性血清性激素及甲状旁腺激素与骨转换生化指标的相关性。方法:收集2011年5~6月在我院常规年度体检年龄≥60岁的老年男性465例,年龄60~93岁。测定血清卵泡刺激素(FSH)、黄体生成素(LH)、雌二醇(E2)、睾酮(T)、性激素结合球蛋白(SHBG);血清甲状旁腺激素(PTH)、25-羟化维生素D3(25(OH)D3);骨转换生化指标(I型胶原羧基末端肽:CTX;骨钙素:OC;Ⅰ型前胶原氨基末端前肽:PINP);并计算游离睾酮(FT)、生物可利用睾酮(BT)、睾酮分泌指数(TSI)和游离睾酮指数(FTI);分析各指标与老年男性骨转换生化指标的相关性。结果:老年男性血清FSH、LH、SHBG水平随年龄增加而升高,而FT、BT、TSI、FTI、PTH及CTX、OC和PINP随增龄呈下降趋势,80岁以后下降较为显著(P0.05)。PTH与CTX、OC和PINP均呈正相关(r=0.227,0.269,0.162;P0.01),校正年龄因素后,相关性仍然存在;SHBG与OC负相关(r=-0.100,P0.05)。各骨转换指标随PTH四分位水平升高而增加,第一分位与第四分位之间均存在显著差异(P0.01)。多元逐步回归结果显示,年龄与CTX、OC和PINP负相关(β=-0.126,-0.141,-0.122;P0.05),PTH与CTX、OC和PINP正相关(β=0.196,0.279,0.189;P0.001),SHBG与OC负相关(β=-0.100,P0.05)。结论:增龄是老年男性骨转换减低的根本原因,血清PTH和SHBG水平与骨转换生化指标相关。     

围绝经期女性腰椎椎间盘退变程度的MRI观察

目的探讨围绝经期女性腰椎椎间盘MRI特点及相关退变规律。方法随机选择2014年1月—12月来本院就诊的成年男女患者各420例,记录患者年龄、身高、体质量指数(BMI)、吸烟史、高血压史、糖尿病史、月经史、职业等,每位患者均行腰椎MRI检查。女性患者按照月经史分为5个组:绝经前组(n=76),绝经0年且6年组(n=98),绝经≥6年且11年组(n=82),绝经≥11年且≤15年组(n=80),绝经15年组(n=84)。用Pfirrmann分级系统对腰椎椎间盘退变程度进行分级,用SPSS 19.0软件进行相关数据分析。结果男女患者年龄、BMI、糖尿病史、高血压史、职业等差异无统计学意义(P0.05);男性吸烟率明显高于女性,差异有统计学意义(P0.05)。男性患者Pfirrmann分级≥Ⅲ级的椎间盘比例高于女性(男78.2%,女60.8%),差异有统计学意义(P0.05);PfirrmannⅣ、Ⅴ级时差异更显著。在女性亚组中,绝经前组各椎间盘水平Pfirrmann平均分均显著低于各绝经组,差异有统计学意义(P0.05)。绝经≤15年时,绝经年限越高,L_1/L_2、L_2/L_3、L_4/L_5及L_5/S_1椎间盘Pfirrmann平均分越高,差异有统计学意义(P0.05);绝经≥11年且≤15年组与绝经15年组间各节段椎间盘Pfirrmann平均分差异均无统计学意义(P0.05)。结论男性患者腰椎椎间盘退变较女性严重。绝经后女性腰椎椎间盘退变较绝经前严重,且在绝经≤15年时,绝经年限越长,退变越严重;绝经15年后,腰椎椎间盘退变进程减缓。因此,雌激素水平下降可能是腰椎椎间盘退变的危险因素。     

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.

     

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.     

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.     

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.