Leukotriene pathway inhibitors in asthma and chronic obstructive pulmonary disease

Leukotrienes can be generated from a wide variety of cells including mast cells and eosinophils. The biological properties of these products include bronchial smooth muscle contraction, stimulation of mucous production, enhancement of vascular permeability, and recruitment of eosinophils. These properties can contribute significantly to the pathobiology of asthma. Recently, zafirlukast and montelukast, and zileuton, leukotriene D₄ receptor antagonists and 5-lipoxygenase inhibitors, respectively, have been developed and are available for treating asthma. Studies have found these compounds modify bronchospasm with exercise, the pulmonary reaction to aspirin in sensitive subjects, and the airway response to inhaled antigen. Furthermore, in patients with chronic asthma, leukotriene modifiers improve airflow obstruction, decrease the need for rescue medication, and diminish symptoms. Moreover, these drugs can prevent asthma exacerbations. However, there is little evidence that these medications have potent anti-inflammatory activity. Nonetheless, leukotriene modifiers represent new, and effective, therapeutics in the treatment of asthma; at present, the positioning of these products in relationship to inhaled corticosteroids, for example, in the treatment of asthma has not been fully defined but will emerge with further study and use in the clinic setting.     

Endovascular Surgery in the Treatment of Chronic Primary and Post-thrombotic Iliac Vein Obstruction

OBJECTIVES: To compare the results and complications of endovascular surgery in limbs with post-thrombotic and non-thrombotic disease and to detail some technical aspects of the procedure. DESIGN: A single centre, prospective study. MATERIALS AND METHODS: Between March 1997 and August 1999, 139 consecutive lower extremities with chronic iliac venous obstruction (61 limbs with primary disease [MTS] and 78 with post-thrombotic disease [PTS]) were treated by balloon dilation and stenting. History, clinical examination, procedure and follow-up data were recorded. RESULTS: Mortality was zero. Non-thrombotic complication rate was only 3%. Postoperative (8%, 6/78) and late occlusion (3%, 2/69) occurred only in post-thrombotic limbs. Primary, primary-assisted and secondary cumulative patency rates of the stented area at 2 years were 52%, 88% and 90%, respectively, in the PTS group as compared to 60%, 100% and 100% in the MTS group. Clinical improvement in pain and swelling was significant in both groups. Half of active venous ulcers healed after the procedure. CONCLUSIONS: Chronic iliac vein obstruction appears to be a symptomatic lesion that can be treated safely and effectively by endovascular surgery regardless of aetiology. Generous use of IVUS is suggested in both diagnosis and treatment since phlebography is unreliable. The clinical improvement was significant in both groups; however, more excessive neointimal hyperplasia and a higher early and late occlusion rate were observed in post-thrombotic disease. Stenting after balloon dilation is advised in all venoplasties; stents should be inserted well into the IVC when treating iliocaval junction stenosis. A wide-diameter (16 mm) stent is recommended. The stent should cover the entire lesion as outlined by the IVUS.     

Acute renal failure due to obstruction in Burkitt lymphoma

 Acute renal failure in Burkitt lymphoma is commonly the result of tumor lysis syndrome. We present a 15-year-old boy who developed hypertension, seizures, and acute renal failure due to extrinsic compression of the bladder and ureters by a large retrovesical Burkitt lymphoma. The causes of acute renal failure in Burkitt lymphoma and the incidence of acute urinary obstruction in this disease are reviewed. Received: 18 May 1998 / Revised: 30 June 1998 / Accepted: 1 July 1998     

先天非结石梗阻性肾积水影像诊断与病理基础

目的:回顾分析输尿管先天非结石梗阻性肾积水影像特征,提高对肾积水致病原因及输尿管无病变侧肾继发性改变特征的识别能力。方法:根据静脉肾盂造影、逆行肾盂造影、B型超声波及CT检查结果,经手术和病理证实的输尿管先天非结石梗阻性肾积水86例进行对照研究。结果:中、重度肾积水占86.0%,致病因素中输尿管狭窄占83.7%,其中一侧输尿管多处狭窄和(或)双侧输尿管狭窄占20.9%。肾积水的不同影像特征与输尿管梗阻的部位不同有关,轻度肾积水的肾盂改变类似"壶腹"型肾盂。结论:先天非结石梗阻性肾积水的病因多样,但多伴有输尿管狭窄。输尿管狭窄具有单侧多发及双侧同时发病的特点。一侧肾重度积水时,另一侧肾盂改变注意不要误诊为"壶腹"型肾盂。输尿管狭窄的定位诊断以逆行肾盂造影与静脉肾盂造影相结合为首选。     

从经络调养平衡论治胸痹经验

从胸痹的病因病机、胸痹与经络的关系(经络阻滞不通是胸痹形成的首要因素、经络不通使胸痹的病情加重)论述从经络调养平衡论治胸痹。指出:应用经络的调养法促进人体气血运行,调畅气机,消散瘀痹,恢复人体的阴阳平衡的理念治疗胸痹不失为一种有效的治疗胸痹的方法。     

Refractory overactive bladder after urethrolysis for bladder outlet obstruction: management with sacral neuromodulation

Refractory overactive bladder (OAB) after urethrolysis for iatrogenic bladder outlet obstruction (BOO) is a clinical dilemma without established guidelines for management. We sought to evaluate the efficacy of sacral neuromodulation (SNM) in the management of this complex patient population. Retrospective review identified eight patients who underwent SNM secondary to refractory OAB after urethrolysis or sling take-down. SNM was performed with the Interstim® device (Medtronic, Minneapolis) using a two-stage implant technique. SNM outcomes were determined subjectively during follow-up. Validated questionnaires were completed to assess symptom bother, patient satisfaction, and quality of life. Statistical analyses were conducted using Stata® version 9.0. Six patients had a favorable response to SNM during test stimulation and underwent implantation of the implantable pulse generator (IPG). With follow-up of 15.7?±?11.1 months (6–34), all patients significantly improved, with three patients being dry and three patients having one to two urgency incontinence episodes per week. Patient-reported outcomes indicated that patients perceived themselves as very much improved (3) or much improved (3) after SNM, while those failing test stimulation perceived no change. Quality of life and symptom bother were significantly better in SNM responders vs nonresponders. SNM appears to be an effective and viable treatment option in this complex patient population. Further work is needed to determine clinical factors predictive of outcome and durability of response.     

Covered expandable nitinol stents for malignant gastroduodenal obstructions

Background and Aim:  The aim of the present study was to investigate the clinical effectiveness, safety, and outcome associated with the use of covered expandable Nitinol stents (Taewoong Medical, Seoul, Korea) for the treatment of malignant gastroduodenal obstructions.
Methods:  Between March 2001 and October 2004, covered expandable Nitinol stents were placed in 68 consecutive patients under endoscopic and fluoroscopic guidance for the following reasons: gastric carcinoma ( n  = 49), recurrent carcinoma after partial gastrectomy ( n  = 7), or another malignant neoplasm involving the duodenum ( n  = 12).
Results:  Technical success was achieved in 60 of the 68 patients (88.2%). After stent placement, mean dysphagia score improved from a mean of 3.5 to 1.2 ( P  < 0.001). The mean period of primary stent patency was 107.2 days. During follow up (mean 4.4 months; range, 1–15 months), major complications (migration [6], bleeding [3], perforation [1], ingrowth [1], overgrowth [7], fistula [1]) occurred in 19 patients (27.9%), and stent migration occurred in six (8.8%) (proximal migration into the stomach [ n  = 3], or distal migration [ n  = 3]). Recurrent dysphagia (mainly due to tumor ingrowth/overgrowth) occurred in eight patients (11.8%).
Conclusion:  Covered expandable Nitinol stents appear to offer an effective and feasible palliative therapy in patients with a malignant gastroduodenal obstruction.     

TRANSECTION OF METAL STENTS USING ARGON PLASMA COAGULATION

Background: Placement of self‐expandable metallic stents has become the preferred palliative treatment for patients with unresectable malignant biliary obstruction. Metallic stents provide longer patency compared with plastic stents. Distal malposition or migration of metallic stents sometimes occurs, but it is often difficult to remove them. We evaluated the efficacy and safety of argon plasma coagulation (APC), and the optimum conditions for cutting metallic stents (Wallstent). Methods: We wrapped porcine small intestines around a metallic Wallstent with and without silicon lining membrane (Permulume®), leaving the distal portion unwrapped to resemble the protrusion of the biliary metallic stent from the ampulla of Vater. APC irradiation was applied to the metallic stent at 1 cm from the edge of the wrapped small intestine at 30, 60 and 99 watts (W) for 3 or 6 s. Results: Metallic Wallstent with the silicone‐based membrane Permalume® was cut at 30 W power, whereas more than 60 W power was required to cut the bare metallic wire. The irradiation of APC (flow rate at 2.0 L/min) at 30 W to the covered metallic stent transected the metallic mesh stent not only under dry but also under wet conditions (moisturized stent). Irradiation of APC caused no gross damage to the small intestines irrespective of the power applied and duration of irradiation. Conclusions: Our results suggest that APC is efficacious and safe for endoscopic sectioning of wire mesh stents at low power (30 W) without gross damage to the surrounding pancreaticobiliary tissues.