Demonstration of Right and Left Atrial Dissociation by Atrial Rapid Pacing or Extrastimulation During Fast-Slow (Uncommon) Form of Atrioventricular Nodal Reentrant Tachycardia

Some recent works suggest that extranodal atrial fibers may form part of the reenlry circuit in the atrioventricular (AV) nodal reentrant tachycardia (AVNRT). This hypothesis is based on the fact that the perinodal dissection successfully abolished AVNRT while preserving intact AV conduction. Apart from the surgical success, the electrophysiological evidence supporting this hypothesis has not been demonstrated, especially in the uncommon (fast-slow) form of AVNRT. We present some electrophysiological evidence suggesting atrial participation in eight patients with the fast-slow form of AVNRT. During the tachycardia, rapid pacing or extrastimulation was done from the orifice of the coronary sinus (CS) and the right atrium (RA), while recording the electrograms of the CS and the low septal RA. In seven patients, right and left atrial dissociation was demonstrated during pacing from the RA, while in the remaining one this was demonstrated from the CS. The interatrial dissociation will be unlikely if the intranodal reentry circuit connects with the atria via a single upper common pathway. This suggests that the upper turnaround of the reentry circuit involves atrial tissue and that the extranodal accessory pathway with long conduction times may form the ascending limb of the circuit (atrionodal reentry). Alternatively, the reentry circuit is entirely intranodal and two or more connecting pathways are present between the atria and the circuit.     

Chrome congestive heart failure: Radiofrequency ablation of accessory pathways: implications of accumulated experience and time dedicated to procedures

Previous reports on radiofrequency ablation of accessory pathwayshave shown that the experience of the operator is of crucialimportance in reducing fluoroscopy time and achieving highersuccess rates. However, a detailed analysis of this importantissue has not been previously attempted We analysed 71 consecutive ablation procedures undertaken atSt George's Hospital by the same electrophysiology group andalways with the same first operator. Of all procedures, 66 (916%)were successful, as judged by abolition of accessory pathwayconduction without recurrence within the next 24 h. Failuresincluded two out of 38 left-sided pathway procedures (5·3%),one out of 11 intermediate septal (9·1%) and four outof 22 right-sided pathway procedures (18·2%). These differencewere not statistically significant. Average procedure and screeningtimes for all procedures were 162·9±86·0min and 56·8±48·2 mm respectively, whereasthe median of the number of discharges was 12, ranging fromone to 51. There was no significant difference between pathwaygroups or between concealed and non-concealed pathways in respectto procedure and screening time or number of discharges. Therewas a significant tendency towards decreased procedure and screeningtimes with accwnulating experience and this was similar forall pathway groups. There was also a tendency towards improvedcwnulative success rates with time dedicated to procedures. We conclude that a certain amount of ablation experience isrequired, even by experienced electrophysiologists, before arelatively high success rate without long radiation exposurecan be achieved, regardless of the location or the mode of conductionof the pathway. Success rates increase with procedure time,suggesting that early abandonment of the procedure may resultin higher failure rates in diffcult cases.     

RESPONSIVENESS AND SENSITIVITY TO CHOLINERGIC AGONISTS AND ANTAGONISTS IN BOVINE ISOLATED BRONCHIAL MUSCLE

1. Airways derived from different levels of the lung exhibit a difference in the reactivity and sensitivity to agonists. We have evaluated the effect of acetylcholine and cholinergic selective (pirenzepine, gallamine and 4-dipherylacetoxymethyl piperidine [4-DAMP]) and non-selective (atropine) antagonists on bovine proximal and distal smooth muscle preparations. 2. The distal preparations are more sensitive to acetylcholine than proximal bronchi. The relaxant effect of three selective antagonists on the distal and proximal tissues was the same when the results for each drug were compared. 3. Atropine and 4-DAMP were more potent than pirenzepine and gallamine in relaxing both proximal and distal bovine smooth muscle preparations. 4. These data suggest that the muscarinic sites on the smooth muscle of bovine airways are of the M3 subtype.     

Neuronal adrenergic and muscular cholinergic contractile hypersensitivity in canine jejunum after extrinsic denervation

Extrinsic denervation may be responsible for motor dysfunction after small bowel transplantation. The aim of this study was to examine the role of extrinsic innervation of canine jejunum on contractile activity. An in vitro dose response of cholinergic and adrenergic agonists was evaluated in canine jejunal strips of circular muscle at 0, 2, and 8 weeks in a control group and after jejunoileal extrinsic denervation (EX DEN). Neurons in circular muscle were quantitated by means of immunohistochemical techniques. Adrenergic and cholinergic responses did not differ at any time in the control group. However, at 2 and 8 weeks, extrinsic denervation caused an increased sensitivity to the procontractile effects of the cholinergic agonist bethanechol at the level of the smooth muscle cells, and increased sensitivity to the inhibitory effects of the adrenergic agent norepinephrine mediated at the level of the enteric nervous system. Immunohistochemical analysis showed a reduction in all neurons and a complete lack of adrenergic fibers in the EX DEN group after 2 and 8 weeks. Extrinsic denervation induces enteric neuronal cholinergic and adrenergic smooth muscle hypersensitivity in canine jejunal circular muscle. Presented in part at the annual meeting of the American Gastroenterological Association, Orlando, Florida, May 18, 1999 (poster presentation), and published as an abstract in Gastroenterology 116:A1075, 1999. Supported by United States Public Health Service grant DK39337 from the National Institutes of Health (M.G.S.); the Swiss National Science Foundation; the Swiss Society of Gastroenterology and Hepatology; the Swiss Foundation for Medical and Biological Science; the Novartis Foundation; Astra Zeneca Pharmaceuticals, Switzerland; and the Department of Visceral and Transplantation Surgery, University of Bern, Switzerland.     

Total and free tissue factor pathway inhibitor in pregnancy hypertension.

OBJECTIVE: To clarify the role played by tissue factor pathway inhibitor (TFPI) in pregnancy hypertension. METHODS: Using enzyme-linked immunosorbent assays, hemostatic measurements were obtained for women with pre-eclampsia (n=51), nonproteinuric hypertension of pregnancy (n=62), postpartum pre-eclampsia 24 h after childbirth (n=31), and no hypertension (healthy pregnant controls, n=100). RESULTS: There was a significant increase in circulating free TFPI levels in women with pre-eclampsia (9.7+/-6.2 ng/mL) or nonproteinuric hypertension of pregnancy (8.3+/-5.3 ng/mL) compared with healthy controls (5.3+/-2.1 ng/mL). In women with pre-eclampsia the levels remained elevated after placental delivery (10.6+/-4.0 ng/mL). Free protein S levels were significantly higher in women with pre-eclampsia (40.0%+/-10.7%), nonproteinuric hypertension of pregnancy (37.1%+/-12.5%), or postpartum pre-eclampsia (39.3%+/-9.1%) than in healthy pregnant controls (32.2%+/-8.5%). CONCLUSION: Increased levels of the physiologically active free forms of TFPI and free protein S, 2 coagulation inhibitors, may protect women with pregnancy-induced hypertension from the risks of hemostatic activation.     

白细胞介素6、信号传导和转录活化因子3和血管内皮生长因子在人脑胶质瘤中的表达及相关性研究

目的研究人脑不同级别胶质瘤中白细胞介素（IL）-6，信号传导和转录活化因子3（STAT3）和血管内皮生长因子（VEGF）的表达，探讨IL-6、STAT3和VEGF与肿瘤病理级别和侵袭性的关系。方法采用免疫组织化学法，检测70例人脑胶质瘤，10例脑膜瘤和5例正常脑组织中IL-6、STAT3和VEGF的表达。结果胶质瘤中IL-6、STAT3和VEGF的表达水平在高级别组（Ⅲ、Ⅳ级）明显高于低级别组（Ⅰ、Ⅱ级），两组间差异有统计学意义（P〈0．01），STAT3的表达与IL-6和VEGF的表达均呈正相关（P〈0．01）。结论IL-6、STAT3和VEGF的表达与胶质瘤的恶性程度有密切关系；且三者协同在胶质瘤发生、发展过程中起重要作用。三者的相关性证实VEGF基因由STAT3蛋白调节，而STAT3又由IL-6刺激活化。     

新法加工附子与附片抗炎镇痛作用比较研究

目的：比较新法加工附子在总生物碱高于附片13倍时，其抗炎、镇痛的效果是否有差异。方法：通过小鼠热板法、扭体法、小鼠耳廓肿胀法和大鼠足趾肿胀法进行镇痛和抗炎作用比较。结果：二者对热板法小鼠的痛阈值均无提高．均能减少酒石酸钾所致小鼠扭体次数．对二甲苯所致小鼠耳廓肿胀和角叉菜胶所致大鼠足趾肿胀具有抑制作用。但二者之间比较差异无显著性。结论：新法加工附子保存了其原有疗效，但和总生物碱无量效相关性，其中是否有新的活性成份，有待进一步研究探讨。     

临床路径在大肠癌手术患者中的应用

目的:研究临床路径在大肠癌手术患者中的应用效果。方法:选择广东省江门地区某三甲医院2006年7月至2007年12月间实施临床路径的大肠癌手术患者192例作为实验组,对照组选择该院2005年1月至2006年6月间未实施临床路径按常规模式实施的大肠癌手术患者174例,比较两组患者在住院日、住院费用、患者满意度等方面有无差异性。结果:实验组患者的平均住院日、住院费用等方面明显低于对照组(P<0.01),患者满意度优于对照组(P<0.01)。结论:按临床路径对大肠癌手术患者实施围手术期诊疗护理计划,可减少患者平均住院日,降低住院费用,提高医疗护理服务质量及患者满意度,为进一步扩大临床路径的临床应用范围提供实验数据。     

Mapping the rat somatosensory pathway from the anterior cruciate ligament nerve endings to the cerebrum

The anterior cruciate ligament (ACL) serves as the primary restraint to anterior tibial translation. In addition to this biomechanical function, the ACL appears to have a function in neuromuscular control. This hypothesis was formulated after the discovery of mechanoreceptors within the ACL. The full somatosensory pathway from the ACL to the cerebrum has yet to be elucidated. In order to map this sensory pathway, we conducted a viral trans-synaptic tracing experiment using the neurotropic pseudorabies virus (PRV). The pseudorabies virus was injected into the ACL of rats and allowed to replicate and spread trans-synaptically for 6-7 days. The brain and spinal cord of each sacrificed rat was then removed and processed immunohistochemically to detect the presence of PRV. PRV-immunoreactive neurons were found to be localized in several different regions from the spinal cord to the cerebrum. Four nuclei in the reticular formation of the brain stem demonstrated strong positive labeling: the mesencephalic reticular nucleus, magnocellular reticular nucleus, paragigantocellular reticular nucleus, and gigantocellular reticular nucleus. This finding suggests that the nerve endings of the rat ACL project into the cerebrum and that the reticular formation may play an important role in the afferent pathway of those nerve endings.     

The anti-inflammatory profile of fluticasone propionate

Fluticasone propionate is a new corticosteroid based on the androstane nucleus. It is more lipophilic than beclomethasone dipropionate (BDP) and budesonide, and binds more avidly to human lung tissue. It has an absolute affinity (K_D) of 0.5 nM for the glucocorticoid receptor and a relative receptor aflinity 1.5- and 3.0-times greater than that of beclomethasone-17-monopropionate (17-BMP) and budesonide, respectively. The rate of association with the receptor is faster and the rate of dissociation slower than with standard corticosteroids. As a result, the half-life of the corticosteroid-receptor complex is >10 h. Fluticasone propionate is also highly selective for the glucocorticoid receptor, with little or no activity at other steroid receptors. Pretreatment with fluticasone propionate signiflcantly inhibits the increase in mast cell numbers in the nasal mucosa of rats chronically exposed to toluene di-isocyanate (TDI), and suppresses TDI-induced mast cell degranulation. It is more potent in vitro than dexamethasone, BDP and budesonide in inhibiting anti-CD3-induced human T-lymphocyte proliferation, in attenuating tumour necrosis factor-α-induced endothelial cell adhesion molecule expression, and in increasing secretory leucocyte protease inhibitor levels in airway epithelial cells. It is also more potent and longer-acting than other corticosteroids in inhibiting oedema formation, interleukin-5 (IL-5)-induced blood eosinophilia, and IL-5- or platelet activating factor-stimulated eosinophil accumulation in the lung. Fluticasone propionate therefore has increased intrinsic glucocorticoid potency and high topical anti-inflammatory activity.