Nitric oxide synthase activity is inducible in rat,but not rabbit alveolar macrophages,with a concomitant reduction in arginase activity

Alveolar macrophages were obtained by broncho-alveolar lavage of isolated rat and rabbit lungs and cultured (2.5 × 10⁶ cells/dish) for 18 h in the absence or presence of bacterial lipopolysaccharides (LPS) alone or in combination with cytokines. Thereafter, accumulation of ³H-citrulline (NO synthase activity) and ³H-ornithine (arginase activity) were determined.During incubation of rat alveolar macrophages with ³H-arginine clear amounts of ³H-citrulline and ³H-ornithine (3.8 and 4.6% of the added ³H-arginine, respectively) were formed and most of these metabolites appeared in the incubation medium (ratios extra-/intracellular of 17 and 70 for ³H-citrulline and ³H-ornithine, respectively). When rat alveolar macrophages had been cultured with LPS the formation of ³H-citrulline was increased about 30-fold and this was accompanied by a reduction in ³H-ornithine formation of about 60%. The effects of LPS were largely attenuated by dexamethasone (10 mol/1). Inhibition of NO synthase by N^G-monomethyl-l,-arginine (l-NMMA, 100 mol/1) in LPS treated alveolar macrophages reduced the formation ³H-citrulline by more than 90% and restored the ³H-ornithine formation. After culturing in the presence of LPS the ratios extra/intracellular of ³H-citrulline and ³H-ornithine were markedly enhanced and this effect was not dexamethasone sensitive. During incubation of rabbit alveolar macrophages a marked formation of ³H-ornithine (about 5.3% of the added ³H-arginine), but no significant formation of ³H-citrulline could be detected. Pretreatment with LPS tended to enhance the formation of ³H-ornithine (by 50%) without effects on ³H-citrulline. Rabbit-interferon and/or tumor necrosis factor- present together with LPS during the culture period did not result in a significant ³H-citrulline formation. Under all conditions tested, culture media of rabbit alveolar macrophages did not contain significant amounts of nitrite (less than 0.5 nmol) whereas in culture media of untreated rat alveolar macrophages 22 nmol nitrite (per 18 h) were detected, and LPS induced a 3-fold nitrite accumulation, an effect prevented by dexamethasone.In conclusion, in rabbit alveolar macrophages NO synthase activity was not detectable and could also not be induced by LPS and different cytokines, whereas in rat alveolar macrophages NO synthase was readily inducible. Alveolar macrophages of both species showed marked arginase activity. After induction of marked NO synthase activity, ornithine formation was largely reduced possibly by concomitant inhibition of arginase and/or withdrawn of arginine from arginase.     

Effects of selective phosphodiesterase inhibitors on platelet-activating factor- and antigen-induced airway hyperreactivity, eosinophil accumulation, and microvascular leakage in guinea pigs

There is currently interest in the potential use of selective inhibitors of cyclic nucleotide phosphodiesterases (PDE) in the treatment of asthma. In this study we examined the effects of three selective PDE inhibitors, milrinone (PDE III), rolipram (PDE IV) and zaprinast (PDE V), on the broncoconstriction produced by antigen and histamine, the airway hyperreactivity and microvascular leakage after aerosol exposure to platelet-activating factor (PAF) and antigen, and the antigen-induced eosinophil infiltration in guinea-pig lung. Inhaled rolipram (0.01–10 mg ml^–1) inhibited dose dependently the bronchospasm produced by aerosol antigen (5 mg ml^–1) an anaesthetised, ventilated guinea-pigs. Rolipram (10 mg ml^–1) produced maximal inhibition of antigen-induced bronchoconstriction but only partial inhibition of the response to aerosol histamine (1 mg ml^–1). Milrinone and zaprinast (each 10 mg ml^–1) showed weak, or no, inhibitory effects against bronchoconstriction produced by aerosol antigen or histamine. Pretreatment with rolipram (10 mg kg^–1, i.p.) prevented airway hyperreactivity to histamine which develops 24 h after exposure of conscious guinea-pigs to aerosol PAF (500 g ml^–1) or antigen (5 mg ml^–1). The pulmonary eosinophil infiltration obtained with 24 h of antigen-exposure was inhibited by rolipram. In contrast, milrinone and zaprinast (each 10 mg kg^–1, i.p.) failed to reduce either the airway hyperreactivity of the eosinophil accumulation in these animals. Rolipram (1–10 mg ml^–1) reduced the extravasation of Evans blue after aerosol PAF (500 g ml^–1) at all airway levels while a lower dose (0.1 mg ml^–1) was only effective at intrapulmonary airways. Rolipram (0.01–1 mg ml^–1) markedly reduced airway extravasation produced by inhaled antigen (5 mg ml^–1). Zaprinast (1–10 mg ml^–1) was also effective against airway microvascular leakage produced by aerosol PAF or antigen while milrinone (10 mg ml^–1) had no antiexudative effect. These data support previous suggestions that pharmacological inhibition of PDE IV results in anti-spasmogenic and anti-inflammatory effects in the airways and may be useful in the treatment of asthma.     

Emergency ventilation using the Combitube in cases of difficult intubation

Summary The esophageal-tracheal Combitube (Sheridan, Argyle, NY) is a new device for emergency intubation, which can be inserted blindly without the use of a laryngoscope. Ventilation is independent of the position of the Combitube in either the esophagus or the trachea, since ventilation is always provided by the tube's double channel. The tracheal channel acts as a conventional endotracheal airway and has an open distal end. The esophageal channel has a blocked distal end, so that together with the inflated distal cuff it acts as an esophageal obturator in cases of esophageal intubation. Perforations at the pharyngeal section direct the airflow to the trachea. At the oropharyngeal section a large elastic balloon is positioned in order to obturate the oral cavity and the nasopharynx. Two patients are described to exemplify the Combitube's clinical use. Both had rapidly enlarging cervical hematomas causing upper airway obstruction and thus requiring immediate intubation. Endotracheal intubation failed because the glottis could not be visualized with a laryngoscope. In both cases the Combitube was applied successfully and adequate ventilation was provided via the Combitube placed esophageally. To better secure each patient's airway, tracheotomy was performed during ventilation without any complications.     

Effects of intravenously administered lidocaine on pulmonary vagal afferents and phrenic nerve activity in cats

The ability of lidocaine to suppress activity of single vagal afferent fiber and that of phrenic nerve was studied in 20 cats anesthetized with pentobarbital. Slowly adapting stretch receptors (SAR, n = 16) and rapidly adapting stretch receptors (RAR, n = 7) were identified by their discharge pattern to pulmonary inflation. Intravenous lidocaine (1mg·kg^–1 or 2mg·kg^–1) produced a suppression of SAR activity but not of RAR activity. Suppression of phrenic nerve activity lasted much longer than that of SAR. These findings indicate that iv lidocaine acts more dominantly on CNS than on peripherals. We conclude that iv lidocaine prevents cough and hemodynamic changes caused by airway manipulation mainly through its action on CNS and not on peripherals (peripheral nerves or their receptor).(Aoki M, Harada Y, Namiki A, et al.: Effects of intravenously administered lidocaine of pulmonary vagal afferents and phrenic nerve activity in cats. J Anesth 6: 395–400, 1992)     

Anesthetic management of a patient with Hallermann-Streiff syndrome

Key words  airway management - difficult intubation - Hallermann-Streiff syndrome     

Vascular compression of the airway: Indications for and results of surgical management

Vascular compression of the airway is a significant cause of respiratory compromise in children. While the indications for surgical repair are sometimes life threatening, they can also be subtle. This retrospective study examines 45 surgical cases of tracheobronchial compromise secondary to vascular compression at a large children's hospital between July 1983 and February 1996. A total of 34 were diagnosed with innominate artery compression, ten with a double aortic arch and one with an anomalous right subclavian artery. The 45 patients, 25 male and 20 female, ranged in age from 12 days to 11 years at surgery (average 13 months). A total of 21 (47%) presented with proven or suspected episodes of cyanosis or apnea. All 45 patients had evidence of vascular compression during microlaryngoscopy and bronchoscopy. The diagnosis was confirmed by magnetic resonance imaging (MRI) in 23/45 (51%), barium swallow in 22/45 (49%) and aortogram in 3/45 (7%). There was one death. One patient had a tracheotomy before surgery and continues to require it after surgery. Complete resolution of symptoms was achieved in 39/45 (87%) with five requiring more than one operation before their symptoms resolved completely. A total of four patients experienced a recurrence of symptoms within a variable length of time after surgery. Surgical indications and treatment alternatives will be discussed.     

Laryngotracheal stenosis in children

The diagnosis of laryngotracheal stenosis should be suspected in children with stridor, feeding difficulties, or atypical croup. Only half of the children with congenital laryngotracheal stenosis require tracheotomy, and many of these children can be decannulated following uncomplicated surgical therapy. In contrast, tracheotomy-dependent patients with acquired laryngotracheal stenosis require more extensive surgical intervention, which should be carried out as early as possible to provide the best opportunity for developing normal oral communication. Received: 8 March 1977 / Accepted: 31 July 1997     

诱导痰在慢性阻塞性肺病气道炎症监测中的应用

目的　观察COPD患者诱导痰细胞学和痰上清液IL -8浓度的变化 ,探讨诱导痰在COPD气道炎症监测中的作用。方法　以 2 6例临床确诊的稳定期COPD患者为研究对象 ,分离诱导痰细胞 ,同时检测痰上清液IL -8浓度和肺功能。并以 15例健康志愿者作为对照组。结果　COPD稳定期组与正常对照组诱导痰细胞总数、巨噬细胞数及中性粒细胞数比较 ,差异有显著性 (P <0 0 1) ;COPD稳定期组中性粒细胞百分率高于正常组 ,(P <0 0 1)。稳定期组诱导痰上清液IL -8浓度与正常组比较差异有显著性(P <0 0 1)。诱导痰上清液IL -8的浓度与FEV1占预计值 %呈负相关关系 (r=-0 5 3 9,P <0 0 1) ;诱导痰PMN数与FEV1占预计值 %呈负相关关系 (r =-0 73 3 ,P <0 0 1) ;AM数与FEV1占预计值 %无相关关系 (r =-0 2 2 3 ,P =0 161)。结论　诱导痰技术无创、简便 ,是监测COPD气道炎症的较理想指标。     

吸入皮质激素等对哮喘急性发作患儿诱导痰液中炎性细胞及炎性介质的影响

目的了解布地奈德联合沙丁胺醇雾化吸入治疗儿童哮喘急性发作前后其气道炎性细胞、白细胞介素 6(IL 6)、IL 8、肿瘤坏死因子 α(TNF α)的变化，探讨其影响机制。 方法对上海市第五人民医院2002 09—2003 12收治的急性哮喘发作患儿采用上述联合治疗1周，共对34例急性发作期、24例缓解期患儿和15名正常儿童的诱导痰液进行炎性细胞计数和分类，测定其中IL 6、IL 8、TNF α水平。 结果急性期哮喘患儿的总细胞数、嗜酸性细胞、中性粒细胞和单核细胞比例及IL 8、IL 6、TNF α水平均高于正常对照组。缓解期哮喘患儿除嗜酸细胞及淋巴细胞比例明显高于正常对照组外，其余上述炎性细胞比例及细胞因子水平均降至正常。 结论布地奈德联合沙丁胺醇雾化吸入可显著降低急性哮喘发作患儿气道分泌物内嗜酸性细胞、中性粒细胞和单核细胞数量及IL 8、IL 6、TNF α水平。     

病毒感染对慢性阻塞性肺疾病患者气道炎症的作用

目的探讨病毒感染与慢性阻塞性肺疾病(COPD)的关系及其对气道炎症的作用. 方法收集COPD急性加重期患者84例及23例健康人血清,应用ELISA方法检测患者呼吸道合胞病毒(RSV)、单纯疱疹病毒Ⅰ型(HSV-1)、副流感病毒(PIV)、巨细胞病毒(CMV)、腺病毒(ADV)的特异性IgM、IgG抗体;根据病毒检测结果及临床表现分成2组:病毒感染组(A组)及细菌感染组(B组);用ELISA法检测A、B两组患者治疗前后诱导痰液中白介素8(IL-8)和肿瘤坏死因子α(TNF-α)的水平. 结果 84例COPD急性加重患者81例检测到病毒抗体,IgM阳性者28例(33.3%),其中RSVIgM比例最高(53.5%),其次为PIV(26.7%);IgM阳性与感冒样症状、无脓痰等有关;经治疗后A、B两组痰液IL-8和TNF-α水平显著降低(P<0.05),A组治疗后IL-8下降更明显(P<0.05),TNF-α水平的变化两组间差异无显著性. 结论病毒感染是COPD急性加重的重要因素,并且可引起气道炎症加重.