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At least 289 records · Page 16Linked to original sources
PubMed1984

Prostaglandin H synthase-dependent co-oxygenation of (+/-)-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene in hamster trachea and human bronchus explants.

The role of prostaglandin H synthase (PHS) in the metabolism of 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP-7,8-diol) has been examined in short-term explant cultures of hamster and human tracheobronchial tissues. Labeled BP-7,8-diol was incubated with the explants in the presence and absence of the PHS substrate arachidonic acid (20:4) and the PHS inhibitor indomethacin. The addition of 10 microM to 200 microM 20:4 to incubations of hamster trachea with 5 microM BP-7,8-diol caused significant increases in the formation of 7r,8t-dihydroxy-9t,10t-epoxy-7,8,9,10-tetrahydrobenzo[ a]pyrene (anti-BPDE). These increases were not seen when 1 microM or 20 microM BP-7,8-diol was employed. The stimulation of anti-BPDE formation was observed after incubations of from 1 to 48 h. This stimulation was inhibited to the basal level by 20 microM indomethacin, supporting the role of PHS in the response. No effect of 20:4 was seen on the uptake of BP-7,8-diol by the tracheas or on the formation of water-soluble metabolites. Significant increases in covalent binding of BP-7,8-diol metabolites to DNA of the tracheal epithelium were also elicited by the addition of 20:4, however these increases were not well correlated quantitatively with the increases in anti-BPDE formation. H.p.l.c. profiles of deoxynucleoside adducts from basal and 20:4-stimulated incubations were qualitatively identical. Far greater variability of metabolism was seen in human bronchus explants, but 20:4-dependent increases in anti-BPDE formation could be demonstrated in those tissues as well. Inhibition of this stimulation by indomethacin was either absent or incomplete. This variation in the effect of indomethacin was explained by the examination of the products of 20:4 metabolism by the two tissues. Hamster trachea produced almost exclusively PHS metabolites whereas human bronchus yielded predominantly products of lipoxygenases, enzymes insensitive to indomethacin. In conclusion, this study indicates that co-oxygenation of chemical carcinogens can occur in hamster and human tracheobronchial tissues. The concentration-dependence observed with BP-7,8-diol, however, suggests that this pathway is of minor importance in the activation of BP in these tissues.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1993

Clinicopathological analysis of 19 cases of isolated carcinoma in situ of the bronchus.

Nineteen cases of isolated squamous cell carcinoma in situ (CIS) of the bronchus were described clinicopathologically from among 149 male heavy smokers with roentgenographically occult lung cancer discovered mainly by mass screening performed from 1982 to 1991. All 19 patients had positive sputum cytology tests and negative chest x-ray films and underwent lobectomy (except one who had segmentectomy because of poor lung function). Prior to operation, localization was accomplished by one to eight bronchoscopies using repetitive brush cytology and biopsy. Five cases were bronchoscopically invisible. Polypoid protuberance was noted in three cases, micronodular swelling in three, thickening of spur in five, and mucosal granularity in three. Histology by serial block sectioning showed that there was no nodal involvement in any cases; the maximum length or diameter was 12 mm. Thirteen tumors were < or = 4 mm, four of which were confined to the spur where they occurred. Follow-up data showed a favorable prognosis. Segmentectomy or sleeve resection of bronchus without mediastinal lymph node dissection may be adequate for CIS.

Aged↗
PubMed2003

Gangliocytic paraganglioma of the bronchus: a case report with follow-up and ultrastructural assessment.

We report a case of gangliocytic paraganglioma of bronchus. A 54-year-old woman underwent bronchoscopy following two episodes of right lower lobe pneumonia over the previous 5 months with unresolved chest radiographic changes. A computerized tomographic scan showed a right lower lobe endobronchial lesion, and at bronchoscopy there was a mass partly occluding the lumen of the bronchus. The biopsy and subsequent bronchoscopic resection showed a tumor with morphologic, immunohistochemical, and ultrastructural features of paragangliomatous, gangliocytic, and Schwann cell differentiation consistent with a gangliocytic paraganglioma. The lesion was treated conservatively with bronchoscopic resection and laser therapy. Histopathologic examination of recurrent tumor at 6 months showed features consistent with paraganglioma. Ten months after initial diagnosis, there was no bronchoscopic evidence of residual tumor. The occurrence of gangliocytic paraganglioma in diverse sites gives cause for the reappraisal of the histogenesis of this fascinating lesion. The variable morphology of this lesion may be an expression of the potential for divergent differentiation of a pluripotent stem cell.

Biopsy↗
PubMed1998

A comparison of the reliability of two techniques of left double-lumen tube bronchial cuff inflation in producing water-tight seal of the left mainstem bronchus.

UNLABELLED: A double-lumen endobronchial tube (DLT) bronchial cuff inflation technique that reliably ensures effective water-tight isolation of the two lungs has not been determined. In this study, 20 patients undergoing thoracic surgery requiring a left DLT had the bronchial cuff of the DLT inflated by one of two techniques. In Group 1, the cuff was inflated to produce an air-tight seal of the left bronchus using the underwater seal technique. In Group 2, the cuff was inflated to a pressure of 25 cm H2O. After bronchial cuff inflation in both groups, water-tight bronchial seal was tested by instilling 2 mL of 0.01% methylene blue (MB) above the bronchial cuff of the DLT. Fifteen minutes later, fiberoptic bronchoscopy was performed via the bronchial lumen of the DLT to determine whether MB had seeped past the bronchial cuff. Cuff volume was 0.75+/-0.64 and 0.76+/-0.46 mL, cuff pressure was 30.1+/-27.0 and 25.0+/-0.0 cm H2O (mean+/-SD), and MB was positively identified in two and five patients in Groups 1 and 2, respectively. The difference in cuff volume and pressure and the higher MB seepage in Group 2 compared with Group 1 was not statistically significant. In both groups, MB seepage occurred only when the bronchial cuff volume was <1 mL and when the patients were positioned in the left lateral decubitus position. These findings suggest that the risk of aspiration is greatest when the DLT is positioned in the dependent lung and when the bronchial cuff volume is <1 mL. IMPLICATIONS: Water-tight sealing of the left bronchus by DLT bronchial cuff was tested after cuff inflation using two different techniques. Neither air-tight bronchial seal nor cuff pressure of 25 cm H2O guaranteed protection against aspiration. The risk of aspiration was greatest when the DLT was positioned in the dependent lung and when the bronchial cuff volume was < 1 mL.

Aged↗
PubMed1985

Esophageal scintigraphy. Esophageal bronchus.

In this report, an esophageal bronchus was identified with radionuclide esophageal imaging. The esophageal bronchus, which arises independently from the esophagus, was demonstrated at the time of gastroesophageal reflux, with tracer being seen in the right lung.

Bronchi↗
PubMed1994

Matched ventilation-perfusion becomes mismatched ventilation-perfusion lung imaging after resolution of carcinoma of the bronchus.

Airway occlusion results in regional alveolar hypoxia followed by reflex hypoxic pulmonary arterial constriction. Ventilation-perfusion imaging demonstrates matched defects. In the two patients reported, occlusion of the main bronchus by bronchogenic carcinoma was resolved--in one case by radiation therapy, and in the other by removal of the tumor mass in the bronchus by bronchial slitted biopsy. The initially matched ventilation-perfusion findings became mismatched. While ventilation was presumed to be normal, pulmonary perfusion was not completely reversed.

Aged↗
PubMed1987

One-lung high-frequency ventilation in the management of traumatic tear of bronchus in a child.

An 8-yr-old child suffered traumatic bilateral pneumothoraces and a ruptured right main bronchus. Surgical repair of the bronchus was postponed for 18 h after a definite diagnosis was established due to severe hypoxemia and hypercarbia. Only left endobronchial high-frequency ventilation with muscle relaxation corrected this pulmonary dysfunction sufficiently to enable surgical intervention.

Accidental Falls↗
PubMed1978

Primary repair for closed lobar bronchus injury.

Primary repair in a 19-year-old male who sustained a closed injury to the right bronchus in an auto accident was performed successfully. A 1.5-cm tear was found at operation extending from the right lower lobe bronchus into its distal portion. Nine months later, the patient showed a patent airway with minimal granulation around one suture.

Adult↗
PubMed1991

Emergency repair of main stem bronchus disruption complicated by anastomotic stenosis: two cases of successful repair by resection and reanastomosis.

The case reports of two patients who developed complete bronchial stenosis after emergency repair of a left stem bronchus disruption are reported. Resection of the stenotic bronchus and reanastomosis restored a normal lung function in both patients. Arguments for a conservative approach, perioperative investigations, and technical data are discussed.

Accidents, Traffic↗
PubMed1995

Successful delayed repair of a complete transection of the right mainstem bronchus in a five-year-old girl: case report.

Bronchial transection of a main bronchus is usually recognized and repaired immediately after injury. Delayed repair is uncommon, especially in pediatric patients. We report a case of delayed repair of a transected right mainstem bronchus in a 5-year-old girl, 3 years after the initial injury. The transected lung re-expanded immediately and showed continued growth 3 years later.

Bronchi↗
PubMed1980

Granular cell myoblastoma of the bronchus.

A granular cell myoblastoma of the bronchus occurring in a 20-year-old man was successfully treated by right lower lobectomy. His symptoms of chest pain and cough, the presence of an obstructing mass in a young patient, and the location of the lesion in a large bronchus on the right side are characteristic of this tumor. Electron microscopic examination of the tumor confirmed the diagnosis.

Adult↗
PubMed1995

Rapid reocclusion of left primary bronchus by fibrinomucinous cast in a case of large cell lung cancer.

This report describes a case of large cell carcinoma of the lung in a patient whose left primary bronchus became completely occluded by a fibrinomucinous cast that recurred within 24 hours despite extensive lavage and removal of the cast via flexible bronchoscopy. The primary tumor involved the aortopulmonary window and was affixed to the pulmonary artery and the aorta, arising from the left upper lobe and extending to the left primary bronchus. The occurrence of a large fibrinous endobronchial cast removed by flexible bronchoscopy forceps, such as we report here, is extremely rare.

Airway Obstruction↗
PubMed2005

Bronchus- and nasal-associated lymphoid tissues.

The bronchus-associated lymphoid tissue (BALT) and the nasal-associated lymphoid tissue (NALT) constitute organized lymphoid aggregates that are capable of T- and B-cell responses to inhaled antigens. BALT, located mostly at bifurcations of the bronchus in animals and humans, is present in the fetus and develops rapidly following birth, especially in the presence of antigens. Humoral immune responses elicited by BALT are primarily immunoglobulin A secretion both locally and by BALT-derived B cells that have trafficked to distant mucosal sites. Similarly located T-cell responses have been noted. On the basis of these findings, the BALT can be thought of as functionally analogous to mucosal lymphoid aggregates in the intestine and is deemed a member of the common mucosal immunologic system. NALT has been described principally in the rodent nasal passage as two separate lymphoid aggregates. It develops after birth, likely in response to antigen, and B- and T-cell responses parallel those that occur in BALT. It is not known whether NALT cells traffic to distant mucosal sites, although mucosal responses have been detected after nasal immunization. NALT appears from many studies to be a functionally distinct lymphoid aggregate when compared with BALT and Peyer's patches. It may exist, however, in humans as a diffuse collection of isolated lymphoid follicles.

Animals↗
PubMed2000

Parasympathetic neurotransmission in rabbit isolated bronchus is modulated at prejunctional sites via endothelinB receptor stimulation.

OBJECTIVE: The aim of this study was to investigate the mechanism involved in endothelin-induced potentiation of the response to parasympathetic nerve stimulation. METHODOLOGY: We used autoradiographic and functional studies in rabbit isolated bronchi. RESULTS: Autoradiography revealed dense binding sites for radiolabelled endothelin-3 over bronchial parasympathetic ganglia. The contractile response of the bronchus to electrical field stimulation was significantly potentiated by endothelin-3, endothelin-1, sarafotoxin S6c and BQ-3020 to 326+/-53%, 293+/-63%, 514+/-119% and 655+/-178%, respectively, of control values. The endothelin-3-induced potentiation of neurally evoked responses was not affected by the presence of propranolol, phentolamine or hexamethonium. The potentiation was also unaltered by pretreatment with the endothelinA receptor antagonist BQ-123 (3 micromol/L), but was significantly reduced in the presence of the combined endothelinA/endothelinB receptor antagonist PD 145065, indicating that the potentiation was mediated via endothelinB receptors. Confirmation of endothelinB receptor involvement in the neuropotentiation was obtained by demonstration of a significant amelioration of the potentiation in the presence of the endothelinB receptor selective antagonist BQ-788, and after endothelinB receptor desensitization by the endothelin, receptor selective agonist sarafotoxin S6b. CONCLUSIONS: These results suggest that the endothelin-induced potentiation of parasympathetic neural responses in the rabbit bronchus is mediated via endothelinB receptor activation.

Animals↗
PubMed1994

Effects of SR 48968 on the neuropeptide gamma-induced contraction of the human isolated bronchus.

Neuropeptide gamma (NP gamma) induced a contractile response of the human isolated bronchus which was potentiated by the neutral endopeptidase inhibitor, phosphoramidon, but was not modified by atropine and indomethacin. NP gamma was 3.31-fold more potent than NKA. Contractile response curves to NP gamma were shifted to the right and maximal responses reduced by the non-peptide NK2-receptor antagonist, SR 48968. The pKB of SR 48968 (8.94 +/- 0.18, n = 15), calculated according to Kenakin (1987) was very close to that reported for [Nle10]-NKA (4-10), a specific agonist of neurokinin NK2-receptors (8.86 +/- 0.13, n = 13), suggesting that the contractile effects of NP gamma on the human isolated bronchus were mediated through NK2A-receptors.

Benzamides↗
PubMed1975

Reduction of antigen-induced contraction of sensitized human bronchus in vitro by indomethacin.

1. Contraction of passively sensitized human bronchus induced by antigen challenge in vitro, was reduced by the prostaglandin F2alpha synthetase inhibitor, indomethacin. 2. Prostaglandin F2alpha was released during challenge and this release was inhibited by indomethacin. 3. There was a significant correlation between prostaglandin F2alpha release and antigen challenge-induced contraction, suggesting that this substance may contribute to the bronchoconstrictor response of sensitized human bronchus to antigen.

Acetylcholine↗
PubMed1983

Effect of steroids on beta-adrenoceptor-mediated relaxation of pig bronchus.

1--Progesterone, testosterone (40 microM), cortisol and cortisol hemisuccinate (80 microM) caused 6-8 fold potentiations of (+/-)-isoprenaline (Iso)-induced relaxations of pig bronchus while several other steroids caused smaller potentiations or had no effect. 2--17 beta-Oestradiol (40 microM) increased the potency of Iso, (-)-adrenaline (Adr) and (-)-noradrenaline (NA) by 10.6, 2.3 and 2.6 fold respectively but had no significant effect on the potency of fenoterol (Fen). 3--Inhibition of catechol-O-methyl transferase (COMT) with U-0521 (30 microM) caused a 6 fold increase in the potency of Iso but failed to alter the potency of Adr, NA or Fen. The extraneuronal uptake inhibitor normetanephrine (50 microM) caused significant 2 fold increases in the potency of Iso and Adr but did not potentiate the responses to NA or Fen. 4--In preparations where the potency of Iso had already been increased by U-0521 (30 microM) or by normetanephrine, 17 beta-oestradiol produced no significant further increase in potency. These results indicate that steroid-induced increases in the potency of catecholamines in pig bronchus can be explained in terms of inhibition of COMT or extraneuronal uptake or both.

Airway Resistance↗