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.     

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.     

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.     

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.

---

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.

     

动静脉穿刺网络课件的开发及其应用

目的:确保护理教学效果，提高教学水平。方法:应用多项信息技术将动静脉穿刺技术制作成教学网络课件，并用于临床教学。结果:该课件在本校园网上运行半年余，2000余人次对其进行访问，受到师生好评。结论:该课件能及时反映动静脉穿刺的最新研究进展及具体操作步骤和使用方法，实现护理教学的直观性和交互性，对护理教学和临床带教指导有一定的借鉴作用。     

Physiology and pharmacology of nausea and vomiting

The physiology of nausea and vomiting is poorly understood. The initiation of vomiting varies and may be due to motion, pregnancy, chemotherapy, gastric irritation or postoperative causes. Once initiated, vomiting occurs in two stages, retching and expulsion. The muscles responsible for this sequence of events are controlled by either a vomiting centre or a central pattern generator, probably in the area postrema and the nearby nucleus tractus solitarius. Drugs which induce vomiting include ipecacuanha, a gastric irritant, and apomorphine, a dopamine-receptor agonist. Opioid drugs also induce vomiting, but opioid antagonists are not useful to treat nausea and vomiting. Anti-emetic drugs consist of a variety of neurotransmitter antagonists and may act in the periphery, the central nervous system or both sites. The most important drugs are antagonists at muscarinic, dopamine D₂, 5-HT₃, histamine H₁ and neurokinin NK₁ receptors. These drugs are discussed with particular attention to post-operative nausea and vomiting (PONV).     

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…     

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.     

血管和心脏因素在烧伤休克发生中的作用机制及休克防治

Shock is one of the most important and common complications in the early stage following severe burn.This article focuses on the main advances in the roles and mechanism of vascular and cardiac factors...     

牙体牙弓颌骨阻力中心及其临床意义

牙体、牙弓及颌骨的阻力中心在正畸矫治力系统中具有重要的意义,也是正畸学领域争论较多的一个问题。Dermaut等研究表明,当力作用于物体阻力中心时,物体将发生平动,否则将发生平动和转动的复合运动。目前,国内外多数学者认为牙体、牙弓及颌骨存在阻力中心,但其位置存在争议。本文就牙体、牙弓及颌骨的阻力中心及其临床意义作一综述。     

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。     

Effect of hemodiafiltration and sepsis on chemotaxis of granulocytes and the release of IL-8 and IL-10

BACKGROUND: Extracorporeal circulation, such as cardiopulmonary bypass and hemodialysis, has been associated with an activation of the immune system. Continuous veno venous hemodiafiltration (CVVHD) is used in critically ill septic patients. During CVVHD, cytokines are excreted in ultrafiltrate. When the membranes, used in CVVHD, are incubated with leukocytes in vitro a slight production of cytokines is observed. Due to the underlying disease it is difficult to investigate the effect of CVVHD in septic patients. We therefore studied the separate effect of CVVHD on the chemotaxis of granulocytes, the proliferation of lymphocytes and the release of IL-8 and IL-10 in healthy pigs compared to an endotoxin and a control group. METHODS: Thirty-one pigs were anesthetized and mechanically ventilated. CVVHD was performed in 10 pigs. Eleven pigs received an infusion of Escherichia coli endotoxin 30 microg/kg, and 10 pigs served as a control group. The chemotaxis of granulocytes was measured in an assay chamber, and the cytokines IL-8 and IL-10 with an enzyme-linked immunosorbent assay. The adhesion molecules CD18 and CD62 on lymphocytes were measured using monoclonal antibodies, and the lymphocyte proliferation was measured without stimulation and in response to mitogens. RESULTS: CVVHD was accompanied by lymphocytopenia and increased spontaneous lymphoproliferative response, but no change in adhesion molecules on lymphocytes or cytokine levels in plasma, and no decrease in the chemotaxis of granulocytes. Following endotoxin we observed a pronounced lymphocytopenia and an increased secretion of IL-8 and IL-10, a decrease in the expression of CD18 on lymphocytes and in the stimulated lymphocyte proliferation and in the chemotaxis of granulocytes. CONCLUSION: CVVHD does not, in contrast to endotoxin-induced sepsis, influence chemotaxis of granulocytes, the production of IL-8 and IL-10 or the proliferation of lymphocytes.     

结直肠印戒细胞癌及黏液腺癌临床与预后差异分析

目的 探讨结直肠黏液腺癌与印戒细胞癌临床病理特点和预后及其关系。方法 分析中山大学附属第一医院胃肠胰外科1994-2007年收治的2089例原发性结直肠癌中的黏液腺癌144例,印戒细胞癌25例的临床资料,比较结直肠黏液腺癌与印戒细胞癌临床病理特点和预后及其之间的关系。 结果 黏液腺癌占结直肠癌的5.45%,印戒细胞癌占1.19%;黏液腺癌与印戒细胞癌相比, 印戒细胞癌发病年龄更年轻, 女性易发病, 黏液腺癌好发于结肠而印戒细胞癌好发于直肠（P<0.01）;但在肿瘤直径、淋巴结转移和远处转移和浆膜浸润﹑脏器侵犯﹑根治性切除率﹑中晚期比例等方面二者差异无统计学意义（P>0.05）;印戒细胞癌与黏液腺癌总体存活率相比差异有统计学意义（P<0.05）,可根治手术组总体存活率相比差异有统计学意义（P<0.05）。 结论 印戒细胞癌与黏液腺癌是生物学行为相近而且具有独特的癌变机制的肿瘤,结直肠黏液癌尤其是印戒细胞癌是结直肠癌独立的预后危险因素,其预后差的原因可能与其发生部位和独特的病理类型有关。