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The effect of the enantiomers of formoterol on inherent and induced tone in guinea-pig trachea and human bronchus.

The long-acting beta2-adrenoceptor agonist formoterol is, like all other members of this class of drugs, used as a racemate in the clinic. While the effects of the individual enantiomers have been studied on airway smooth muscle from guinea pig, comparable data on human bronchial smooth muscle are scanty or absent. Therefore, we compared the effects of the enantiomers of formoterol on inherent and induced tone in isolated human bronchi with that on guinea-pig trachea in vitro. The human bronchi either were studied under resting tension conditions or were precontracted with 10 microM carbachol or 0.1 mM histamine. The guinea-pig trachea was precontracted with 0.01, 0.1 or 1 microM carbachol. The racemate and (R,R)-formoterol caused a concentration-dependent relaxation of all preparations with an EC50 of about 1 nM. In the guinea-pig trachea, the concentration-effect curve for formoterol was moved to the right in response to an increased concentration of carbachol. In both human bronchus and guinea-pig trachea, (S,S)-formoterol was more than 1,000 times less potent than (R,R)-formoterol. Thus the relaxing effect of formoterol in human airways as well as in guinea-pig trachea was shown to lie with the (R,R)-enantiomer. Notably, (S,S)-formoterol did not exert any contractile effects within the tested concentration range in either airway preparation. Therefore, we conclude that with regard to relaxant effects the pure (R,R)-enantiomer of formoterol does not offer a benefit over the racemate.

Adrenergic beta-Agonists↗

Right pulmonary aplasia, aberrant left pulmonary artery, and bronchopulmonary sequestration with an esophageal bronchus.

Pulmonary aplasia and bronchopulmonary foregut malformations in which a patent communication between the foregut and the pulmonary system is present are rare congenital abnormalities. Pulmonary aplasia associated with a pulmonary sling is an even rarer abnormality. We report a unique case of right pulmonary aplasia, aberrant left pulmonary artery, and bronchopulmonary sequestration with an esophageal bronchus diagnosed by multidetector helical CT.

Abnormalities, Multiple↗

Blunt traumatic rupture of a mainstem bronchus: spiral CT demonstration of the "fallen lung" sign.

Tracheo-bronchial injuries occur in less than 1 % of blunt chest trauma patients. Indirect signs, such as pneumomediastinum, pneumothorax, and/or subcutaneous emphysema, are revealed on admission plain films and chest CT survey. In most instances, however, tracheobronchoscopy is mandatory in assessing the definite diagnosis of tracheo-bronchial lesion. Occasionally, an abnormal course of a mainstem bronchus or a "fallen lung" sign, featuring a collapsed lung in a dependent position, hanging on the hilum only by its vascular attachments, may allow for CT diagnosis of a blunt traumatic bronchial injury.

Adult↗

Ball valve obstruction of a bronchus causing lobar emphysema in a neonate.

Lobar emphysema in the neonate is usually congenital, resulting from cartilage deficiency causing bronchomalacia and distal air trapping. Acquired forms are usually associated with chronic lung disease or endobronchial obstruction such as mucus plugging. We report a pedunculated endobronchial polyp in a 2-month old ex-premature infant causing intermittent hyperinflation of the right middle lobe. The polyp was seen prolapsing in and out of the bronchus intermedius at bronchoscopy. Possible aetiological links with mechanical ventilation are discussed. We also emphasise the value of bronchoscopy prior to lobectomy in cases of congenital lobar emphysema (CLE).

Bronchial Diseases↗

Migratory patterns of thoracic duct lymphocytes into bronchus-associated lymphoid tissue of immunized rats.

Lymphocytes continuously circulate between the bloodstream and lymphoid organs, and their migration into lymphatic tissues presumably occurs through selective mechanisms. Although bronchus-associated lymphoid tissue (BALT) is known as an inductive tissue of the common mucosal immune system, little is known about how effectively the lymphocytes in the blood vessels migrate into the BALT, thereby enabling the BALT to act as an effector tissue in the immunologic responses of the lungs. To analyze whether or not thoracic duct lymphocytes (TDL) from immunized and nonimmunized rats possess different migratory patterns to the BALT, 5-(6)-carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled TDL were injected into rats with BALT hyperplasia that was produced by intratracheal administration of TNP-KLH, and then the number of labeled cells in the BALT were examined by immunohistochemical methods. We studied the following three groups at 12 h after the injection: group A, intraintestinally immunized donors and intratracheally immunized recipients; group B, nonimmunized donors and intratracheally immunized recipients; group C (control group), nonimmunized donors and nonimmunized recipients. Time course studies 0.5, 4, 12, and 24 h after the injection were done in groups A and C. In a cytokinetic study, larger numbers of CFSE-labeled lymphocytes were found at 12 h and 24 h in group A than in group C. At 12 h after the injection, the absolute number of CFSE-labeled lymphocytes per BALT was significantly higher in group A than in group B (p < 0.05), and was lowest in group C. Histologically, there was a marked proliferation of high endothelial venules (HEV), with findings of adhesion and influx of lymphocytes inside the HEV in group A. These observations indicate that the immunized BALT actively recruits immunized TDL through a specific mechanism of lymphocyte-endothelium recognition in HEV, which partially explains the process of BALT development as an effector tissue for local immunity.

Animals↗

Anterior transpericardial closure of a main bronchus fistula after pneumonectomy.

A young woman sustained a penetrating wound to the right anterior chest during a vehicular accident. Septic complications led to emergency pneumonectomy followed by infection of the pleural space and disruption of the right bronchus closure. Her condition improved after creation of a pleural window for dependent drainage and gauze packing of the pleural space. Subsequently, the open bronchial stump was closed utilizing a transpericardial approach through a median sternotomy incision which permitted eventual closure of the pneumonectomy space without thoracoplasty. When the length of the bronchial stump permits its application, the transpericardial approach to postpneumonectomy bronchial fistula closure offers important advantages over conventional transpleural techniques.

Accidents, Traffic↗

Bronchopleural fistula after stapled closure of bronchus.

The incidence of bronchopleural fistula after stapling among 2,243 pulmonary resections at the Rush-Presbyterian-St. Luke's Medical Center has been reviewed. There were 35 fistulas in 1,773 stapled and in 470 sutured bronchi (segmentectomy, 2; lobectomy, 1; bilobectomy, 9; and pneumonectomy, 23). We have found that the stapler is expedient and simple to use, and that it produces a hermetic and uniform closure. The stapler is contraindicated when the bronchus is thickened, inflamed, or of insufficient length. The overall incidence of bronchopleural fistula was 1.6%. Approximately two thirds of the patients with bronchopleural fistula had preoperative radiation therapy or chemotherapy or both.

Bronchial Fistula↗

Blunt traumatic rupture of pulmonary vein, left atrium, and bronchus.

A 22-year-old man fell 12.2 m (40 ft), injuring the right lower lobe bronchus, right inferior pulmonary vein, and left atrium. These injuries were not associated with fractures, cardiac tamponade, or pneumothorax. The severity of injury became apparent only upon right thoracotomy for persistent hemorrhage. This case presented special diagnostic and surgical challenges and suggests a role for the increased use of bronchoscopy in major blunt chest trauma.

Adult↗

Double-lung transplantation using donor lungs with a right tracheal bronchus.

A 58-year-old man underwent sequential bilateral lung transplantation. On the donor heart-lung block, it was discovered that the right apical segment was supplied by a tracheal bronchus. After the separate implantation of both lungs, a right apical segmentectomy was performed and the postoperative course was uneventful. The management of this problem is discussed.

Bronchi↗

Management of a tracheal bronchus in a pediatric lung transplant recipient.

Successful pediatric lung transplantation requires intraoperative identification and management of unforeseen anomalies in the recipient. Effective technical improvisation combines awareness of bronchial anatomic anomalies with experience in recent modifications in airway anastomotic techniques. We report a case of successful bilateral sequential double-lung transplantation in a child with the right upper lobe bronchus arising from the trachea.

Anastomosis, Surgical↗

The sympatomatic treatment of carcinoma of the bronchus using combination chemotherapy.

A study was made of chemotherapy for inoperable carcinoma of the bronchus. Only patients with symptoms directly due to the tumour or with evidence of rapid tumour growth were selected for treatment. Half the patients selected in this way responded and in these patients survival may have been prolonged. The regimen chosen caused the minimum of interference with the patient's life and, by relief of symptoms, appeared to offer an improvement in the quality of life.

Adult↗

The value of a wide range of tests in the assessment of lung function in carcinoma of the bronchus.

Tests of forced ventilation, lung volume, transfer factor, flow-volume and arterial blood gas measurements were made on 209 patients before thoracotomy for carcinoma of the bronchus. The patients whom the surgeons subsequently considered to be unsuitable for operation had significantly poorer results in tests of forced ventilation than those who were selected for operation. There was little or no significant difference between these groups in respect of the RV, TLC, transfer factor and arterial blood gas measurements. There was no marked difference in the results of any of the measurements between those who developed complications and those who were complication free. It was therefore concluded that clinical assessment together with forced ventilation tests could not be bettered by adding further lung function tests, when these were interpreted as simple 'normal or abnormal'. However, more complex analysis of test findings, such as discriminant analysis, may be of more value.

Aged↗

Alpha 1A-adrenoceptors in rabbit bronchus.

In the presence of propranolol, bronchial preparations from rabbits were markedly contracted by norepinephrine and phenylephrine but only slightly by clonidine. The contractile responses to norepinephrine were inhibited by prazosin and by high concentrations of yohimbine. The concentration-response curve of norepinephrine was shifted in parallel by WB4101 and 5-methylurapidil but not by 60-min treatment with chloroethylclonidine. These results suggest strongly that norepinephrine-induced contraction of rabbit bronchus is mediated through alpha 1A-adrenoceptors. Furthermore, cyclooxygenase inhibitors did not influence the response to norepinephrine, so norepinephrine-induced contraction is considered not to be mediated through the release of prostaglandins.

Adrenergic alpha-Antagonists↗

Effect of epithelium removal and of enkephalin inhibition on the bronchoconstrictor response to three endothelins of the human isolated bronchus.

The three endothelins ET-1, ET-2 and ET-3 induced a potent contractile response in the human isolated bronchus with an intact epithelium, which proceeded on two different stages. The first stage was observed at low concentrations (high potency) (10(-12) to 10(-9) M) but corresponded to a low intrinsic activity (Emax maximal effect induced by ACh 10(-3) M), the second stage appeared at higher concentrations and corresponded to higher intrinsic activity. The rank order of potency for the two stages of contractile activity was ET-1 greater than ET-2 = ET-3. Removal of the epithelium significantly enhanced the two stages of the contractile responses to the three endothelins and abolished the differences in potency efficacy that were observed between ET-1, ET-2 and ET-3 when the epithelium was present. Phosphoramidon (10(-5) M), an enkephalinase inhibitor, was as potent as epithelium removal in enhancing the contractile responses to these agonists at low concentrations (first stage of contraction, 10(-16) to 10(-9) M). However, with high concentrations of endothelins (greater than 10(-9) M, second stage of contraction), phosphoramidon was less potent than epithelium removal in enhancing the contractile responses. In epithelium-denuded strips, preincubation with phosphoramidon did not further increase the maximal contractions induced by/or the potencies of ET-1, ET-2 or ET-3. After epithelium removal, responses to low doses of endothelins were attenuated by nicardipine (10(-6) M) whereas responses to high doses of the endothelins were not affected, as was also observed when the epithelium was present. (ABSTRACT TRUNCATED AT 250 WORDS)

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

Influence of (+/-)-CP-96,345 and SR 48968 on electrical field stimulation of the isolated guinea-pig main bronchus.

The aim of this study was to investigate the effects of (+/-)-CP-96,345 and SR 48968, two new nonpeptide antagonists of neurokinin NK1 and NK2 receptors, respectively, on the response of isolated guinea pig main bronchi to electrical field stimulation (EFS). Bronchi were stimulated transmurally with biphasic pulses (16 Hz, 1 ms, 320 mA for 10 s) in the presence of indomethacin (10(-6) M) and propranolol (10(-6) M). Two successive contractile responses were observed. Both responses were abolished by tetrodotoxin (10(-6) M) whereas only the first rapid phase was abolished by atropine (10(-6) M). The late and prolonged second phase was strongly reduced by the neurokinin A (NK2) receptor antagonist SR 48968 (10(-11) to 10(-8) M) with an EC50 of 0.056 nM and a maximal inhibition of 83.3 +/- 10.8% (10(-8) M, n = 4). This second response was partially inhibited by the substance P (NK1) receptors antagonist (+/-)-CP-96,345 (10(-8) to 10(-6) M). An incubation of 2 h was necessary for SR 48968 to inhibit the EFS-evoked noncholinergic contraction. These results confirm that EFS of guinea-pig bronchi involves stimulation of cholinergic and noncholinergic excitatory nerves and demonstrate that the new developed tachykinin receptors nonpeptide antagonists (+/-)-CP-96,345 and especially SR 48968 are potent inhibitors of the noncholinergic contraction induced by EFS of the isolated guinea-pig main bronchus.

Animals↗