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At least 163 records · Page 9Linked to original sources
PubMed1995

Effect of inhaled steroids on cholinergic transmission in human isolated bronchi.

Steroids have been found to facilitate cholinergic transmission in skeletal muscle, but possible effects in airways smooth muscles have not been studied. Therefore, choline acetyltransferase (CAT) activity, tissue content of stored acetylcholine and release of newly-synthesized [3H]acetylcholine were were measured in freshly-dissected human bronchi. All lung tissue was obtained from patients with lung cancer at thoracotomy. Group I bronchi were obtained from patients who also suffered from chronic obstructive bronchitis and had been treated for at least 6 weeks before surgery with daily doses of four puffs of flusinolid. Group II bronchi were obtained from patients who did not suffer from chronic obstructive airways disease and had not been treated with steroids. Neither CAT activity (3.1 nmol.h-1.mg protein-1) nor acetylcholine tissue content (260 pmol.100 mg-1), or electrically evoked [3H]acetylcholine release (about 2,000 dpm.100 mg-1) differed in the two groups. This cross sectional study indicates that inhaled steroids do not change cholinergic transmission beyond the level observed in the airways obtained from patients with lung cancer who do not suffer from chronic airways disease and have not been treated with inhaled steroids. This suggests that inhaled steroids can be given chronically without the induction of a facilitatory side-effect on cholinergic transmission within the airways.

Acetylcholine↗
PubMed1994

"Hot spots" of chromium accumulation at bifurcations of chromate workers' bronchi.

To investigate the mechanisms underlying respiratory tract carcinogenesis in chromate workers, we measured the concentration of chromium in samples of tissues from 50 bronchial bifurcations and other bronchial tissue obtained at autopsy, or during surgical procedures, from 9 exchromate workers known to be at risk of developing lung cancer. The mean duration of exposure was 21 years and the average time between cessation of exposure and death/surgery was 15 years. The area of the tissue samples was measured by image analysis and the chromium concentration determined by neutron activation analysis. Chromium concentrations ranged from 0.04 to 39 x 10(-10) g/microns tissue thickness/mm2 and in 80% of the cases the concentrations were greater at bifurcations than in neighboring epithelial tissue. The mean concentration ratios between bifurcations and adjacent areas were 1.5 (n = 1) in the trachea, 3.0 (n = 9) in the main bronchi, 3.6 (n = 22) in lobar bronchi, and 10.9 (n = 3) in subsegmental bronchi. Our results demonstrated long-term retention of chromium in the bronchial walls of chromate workers and also that chromium concentrations were higher at airway bifurcations than elsewhere, thus providing solid evidence for a deposition "hot spot" concept.

Aged↗
PubMed1994

Bronchial sleeve resection distal to the main bronchi with complete pulmonary preservation. Report on three successful cases.

Three successful cases of low grade malignant bronchial tumors resected by means of a bronchial sleeve resection distal to the main bronchi with complete pulmonary preservation are presented. Reconstruction of the bronchial tree was accomplished by suturing together the distal lobar bronchi and then anastomosing the double-barrel suture to the proximal residual bronchus. All patients presented excellent results, although in one patient postoperative course was complicated by persistent mucopurulent secretions. Bronchial sleeve resection distal to the main bronchi can be successfully performed for benign or low-grade malignant bronchial tumors. Technically, the operation is more complex than standard sleeve resection of the main bronchus and requires an experienced team. Postoperatively, an increased morbidity rate, mostly represented by secretions retention, may usually be anticipated, necessitating an aggressive medical and bronchoscopic management.

Adult↗
PubMed1995

Localization of neutral endopeptidase (NEP) mRNA in human bronchi.

Neutral endopeptidase (NEP) may regulate peptide-induced inflammation in the respiratory tract. It is of interest to determine which respiratory resident cells express NEP. Trachea and bronchi from seven nonsmoking, nonasthmatic subjects were examined. NEP messenger ribonucleic acid (mRNA) was characterized by Northern blot hybridization of cultured human tracheobronchial epithelial and smooth muscle cells, and reverse transcriptase-polymerase chain reaction (RT-PCR) in trachea and bronchi. In situ hybridization with biotin- and 35S-labelled antisense complementary ribonucleic acid (cRNA) probes was used to determine the distribution of NEP mRNA in human bronchial mucosa. NEP-immunoreactive material was detected using MEK10 murine monoclonal antibodies and the immunogold method with silver enhancement. NEP mRNA was 4.5 kb in size in the cultured human smooth muscle and epithelial cells by Northern blot analysis. No evidence was found by RT-PCR for truncated, alternatively spliced NEP mRNAs, such as del exon 16 or del exons 5-18 in human bronchus. NEP mRNA was detected by in situ hybridization in epithelial cells, submucosal glands, bronchial smooth muscle and endothelium. NEP-immunoreactive material was identified in the epithelium, submucosal glands, bronchial smooth muscle, and endothelium, demonstrating an excellent correlation between the distribution of NEP mRNA and the cell surface protein. NEP mRNA and immunoreactive material were excluded from epithelial goblet cell and submucosal gland mucous cell vacuoles. We conclude that the various sites of NEP protein and mRNA expression correlate with the locations of peptide receptors and NEP enzyme function, and are consistent with the hypothesis that NEP may regulate peptide-induced inflammation in human bronchi.

Base Sequence↗
PubMed1998

Long- and short-acting beta2 adrenoceptor agonists: interactions in human contracted bronchi.

The aim of this study was to systematically compare the interaction of the long-acting beta2-adrenoceptor agonists formoterol and salmeterol with short-acting beta2-adrenoceptor agonists in contracted human bronchi. Human bronchi were obtained at thoracotomy from patients with lung cancer. Formoterol or salmeterol at concentrations inducing up to 92 and 94% of their maximal relaxant effect, respectively, were added to bronchial rings contracted with carbachol (10(-6) M). After a time period of 30 min, concentration-response curves for the short-acting beta2-adrenoceptor agonists, salbutamol, terbutaline, isoprenaline and fenoterol were recorded. Administration of equieffective concentrations of salmeterol and formoterol, resulted in only salmeterol inducing a shift to the right of isoprenaline, terbutaline, fenoterol and salbutamol concentration-response curves. The rank order of shift was salbutamol > fenoterol > terbutaline > isoprenaline. Formoterol, up to concentrations of 3x10(-9) M induced submaximal relaxation resulting in no shift in short-acting beta2-adrenoceptor agonist concentration-response curves. Salmeterol but not formoterol appears to antagonize the relaxation of human contracted bronchi induced by short-acting beta2-agonists. These results obtained in vitro cannot be translated in clinical terms. This study, however, highlights the need for clinical studies on the interaction of long-acting and short-acting beta2-adrenoceptor agonists in acute severe asthma.

Adrenergic beta-Agonists↗
PubMed1995

Clinical pharmacokinetic studies of photofrin by fluorescence spectroscopy in the oral cavity, the esophagus, and the bronchi.

BACKGROUND: To optimize photodynamic therapy (PDT) and photodetection of cancer, two important variables that must be considered are the uptake of the dye and the dye contrast between normal and neoplastic tissue after injection. METHODS: To study these variables in a clinical context, an apparatus based on a noninvasive optical fiber that detects the dye by light-induced fluorescence (LIF) was constructed. RESULTS: Studies on the pharmacokinetics of the fluorescent fraction of Photofrin in patients with early squamous cell carcinoma in the oral cavity, esophagus or bronchi show a signal contrast ranging from 1.5 to 3.5 a short time after intravenous injection that rapidly decreases and tends to unity (one) about 12 hours later. The magnitude of this contrast appears to correlate with the staging of the cancer, the more invasive tumors showing the highest contrast. The more invasive tumors also show the highest uptake. The oral cavity pharmacokinetics are similar to those found in the esophagus and the bronchi. CONCLUSIONS: The oral cavity appears to be a good model, with easy access for optimizing photodetection and PDT in the esophagus and the bronchi. These pharmacokinetics can be used directly for optimizing photodetection. However, complementary information on the detailed localization of the drug by fluorescence microscopy and a correlation of these data with tumor necrosis efficacy are necessary to optimize PDT timing and therapeutic gain.

Adult↗
PubMed2002

Polyploidization and centrosome hyperamplification in inflammatory bronchi.

OBJECTIVE AND DESIGN: Inflammatory and tumorous bronchi were screened in order to obtain new tumor relevant cytogenetic parameters. MATERIAL OR SUBJECTS: Bronchial cells of 32 patients were cultivated by standard cell culture procedures. METHODS: Tetraploidy and aneuploidy was determined by enumeration of chromosome 7 and 8 versus the number of centrosomes. The resulting data were correlated with histopathological data. RESULTS: Tetra- and aneuploidy of epithelial cells were detectable in 76% of tumor cell cultures, 75% of high grade inflammatory tissues and 40% of non- and low grade-inflammatory tissues. Additionally, we observed centrosome hyper-amplification and multipolar mitoses not only in the tumor but also in the early stages of inflammation. CONCLUSION: Inflammatory bronchi already show tumor-specific features and may consequently represent the preliminary genetic stage of cancer development in bronchi.

Adult↗
PubMedDate not supplied

Oblique magnetic resonance imaging of the bronchi.

The trachea and main bronchi of a supine patient in a magnetic resonance (MR) scanner are not contained in a single standard coronal plane, but instead intersect this coronal plane at some angle, usually 20 degrees - 35 degrees. We have developed a new MR imaging protocol to determine the oblique imaging plane which best contains the trachea and main bronchi. The resulting oblique images simplify anatomical identification, and allow the user to select additional oblique planes which cut any desired portion of main bronchus in true cross section. Accurate lumen shapes and areas may then be extracted from these cross-sectional images. The method does not require the patient to be moved or rotated, and does not require hardware modification. We demonstrate the clinical application of the protocol with both a normal volunteer and a patient with an endobronchial tumor. The use of gradient echo pulse sequences together with this protocol to distinguish between vessels and bronchi is presented. We provide phantom verification to demonstrate the quantitative accuracy of the method to provide lumen areas.

Humans↗
PubMed1989

[Investigation of two cases of a clinically unknown large cell carcinoma of the lung involved with severe stenosis of the bilateral main bronchi].

Reported are two rare cases of a clinically unknown large cell carcinoma of the lung, associated with severe stenosis of the bilateral main bronchi. Case 1: A 61-year-old man was admitted to our hospital because of chief complaints that included a cough, hemosputum, and dyspnea. Based on the bronchoscopic findings that revealed severe stenosis of the bilateral main bronchi and a specimen that was biopsied from tracheal spur, a diagnosis of large cell carcinoma of the lung was made. Although anticancer chemotherapy and irradiation therapy produced a slight improvement in the patient's symptoms, at the 10th hospital week the patient died of suffocation. Case 2: A 77-year woman was admitted to hospital with chief complaints that included a cough and hemosputum. A bronchoscopy revealed severe stenosis of the bilateral main bronchi. After the 4th hospital day the patient complained of increasing dyspnea. At the 9th hospital day the patient died of suffocation. An autopsy results revealed a large cell carcinoma (giant type) of the lung.

Aged↗
PubMed1985

[Diagnostic value of bronchographic study for the detection of bronchial cancer, originating from bronchi of the 3d to 5th order].

Lung cancers originating from the bronchi of the fourth and fifth generation (the "intermediate" type according to the definition by Walter and Pryce) and a subdivision of "central" tumours originating from the bronchi of the third generation (segmental bronchi) form a clinical entity the common characteristics of which consists in the fact of being placed in the boundary-zone of endoscopic-macroscopic visibility. The definitive diagnostic confirmation of these tumours often requires the application of the bronchologic and radiographic equipment as a whole. Between 1/70 and 12/82 86 bronchographies were performed in 82 patients suffering from a histologically verified bronchogenic carcinoma of the location mentioned above. Eighty one bronchographies could be submitted to a retrospective analysis. Unequivocal signs of tumour were found in 52 cases (64%) and suspicious signs in 24 cases (30%). Five bronchograms failed to demonstrate tumour-suspicious alterations. The results indicate that up to now the bronchography has an unquestionable though strictly limited field of indication in the diagnostics of selected "topically related" lung cancers.

Bronchography↗
PubMedDate not supplied

Three-dimensional display of the bronchi using helical CT.

The purpose of this study was to evaluate the clinical usefulness of three-dimensional (3D) images of the bronchi obtained using helical CT. Thirteen patients with lung cancer, one with tracheal diverticulum, and one with bronchial amyloidosis were examined. The CT scanner employed was the Toshiba Xforce. The helical CT scan cycle consisted of 20 continuous rotations, each requiring 1.5 sec, for a total scanning time of 30 sec. Scans were obtained using a 5-mm X-ray beam width, a 5-mm/1.5 sec couchtop sliding speed, and a 2-mm reconstruction interval. 3D images were reconstructed using a CEMAX VIPstation. The optimal lower and upper threshold CT values for 3D images of the bronchi were -650 and -100 HU, respectively, and 3D images clearly depicted endobronchial lesions. Cartilage crescents were also demonstrated, but longitudinal and circular mucosal folds could not be visualized. In conclusion, 3D images of the bronchi acquired using helical CT were useful in evaluating endobronchial lesions.

Adult↗
PubMed1952

Effect of influenza virus on cilia and epithelial cells in the bronchi of mice.

In order to determine the effect of infection with influenza virus on bronchial cilia of the mouse, ciliary beat has been visualized directly by microscopic examination of the bronchi in slices of fresh lung. Cilia have been shown also in sections of fixed tissue by the use of special silver staining methods. The results have shown persistence of the cilia in spite of severe viral infection and indicate that the lowered resistance to secondary pneumococcal infection which occurs in influenzal pneumonia of the mouse is not due to interference with the ciliary mechanism. By a process of exclusion, the findings give further support to the theory that lowered resistance to pneumococcal infection in influenzal pneumonia is due to edema fluid in the viral lesion furnishing a culture medium for inhaled pneumococci. A widely used method for evaluation of ciliary activity on respiratory epithelia has been the microscopic observation of wave-like movements in reflected light. This activity was observed readily in the bronchi of mice but evidence was obtained showing that at this site it was due to something other than ciliary beat. Further histopathologic observations were made in order to define the lesion of the bronchial epithelium that would permit sparing of ciliated cells. In addition to usual techniques, mice were injected with colchicine for estimation of the rate of cellular proliferation and were exposed to a large dose of roentgen rays to eliminate polymorphonuclear leucocytes. Stains for mucous and for mitochondria were done also. The evidence obtained favors the theory that the viral infection does not destroy any of the cells of the bronchial epithelium. Inclusion bodies were found in the cytoplasm, making it seem likely instead that viral particles grow in colony-like aggregations and that liberation of virus into the lumen takes place not only by simple extrusion of inclusions but also by detachment of inclusion-laden globular portions of the cytoplasm.

Animals↗
PubMed1964

STAPHYLOCOCCI IN BRONCHI OF HOSPITAL PATIENTS: AN AUTOPSY STUDY.

Swabs were taken from the main bronchi of hospital patients at routine autopsy, and cultures examined for the presence of coagulase-positive staphylococci. The proportion of patients yielding positive cultures increased steadily with the length of stay in hospital. There was no correlation between positive cultures and age or sex. The results of this study suggest that bronchi of long-stay patients may form a significant source of dissemination of staphylococci producing "hospital" infections.

Adolescent↗
PubMed1998

Endobronchial photodynamic therapy: comparison of mTHPC and polyethylene glycol-derived mTHPC on human tumor xenografts and tumor-free bronchi of minipigs.

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) with mTHPC and polyethylene glycol-derived mTHPC (pegylated mTHPC) was compared on nude mice bearing human squamous cell carcinoma and adenocarcinoma xenografts. The same treatment regimens were applied to the bronchi of tumor-free minipigs to assess injury to normal tissue. STUDY DESIGN/MATERIALS AND METHODS: Laser light (652 nm, 20 J/cm2) was delivered as surface radiation to the xenografts 4 days after intraperitoneal administration of 0.1 mg/kg mTHPC or an equimolar dose of pegylated mTHPC, respectively. The extent of tumor necrosis was assessed by histomorphometry. Endobronchial PDT was performed on the bronchi of minipigs with the same drug and light doses at drug-light intervals ranging from 12-96 hr. RESULTS: Both sensitizers produced larger necrosis of squamous cell carcinoma and adenocarcinoma xenografts than was observed in untreated controls (P < 0.005). Pegylated mTHPC led to larger tumor necrosis than mTHPC in squamous cell carcinoma (P < 0.001), but not in adenocarcinoma xenografts. mTHPC-PDT resulted in ulceration and necrosis of bronchial mucosa in minipigs at drug-light intervals ranging from 12-48 hr, which was not observed after use of pegylated mTHPC. CONCLUSIONS: In this setting, pegylated mTHPC had advantages as a photosensitiser compared to mTHPC.

Adenocarcinoma↗
PubMed1995

Contractile responses and structure of small bronchi isolated from rats after 20 months' exposure to ozone.

Short-term exposure to high concentrations of ozone has been shown to increase airway responsiveness in normal humans and in all laboratory animal species studied to date. While our knowledge concerning the pulmonary effects of single exposures to ozone has increased rapidly over recent years, the effects of repeated exposures are less understood. The goal of the present study was to determine whether airway responsiveness is increased after near-lifetime exposure to ozone. Airway segments representing approximately eighth generation airways were isolated from Fischer 344 rats of both genders that had been exposed for 6 hr per day, 5 days per week for 20 months to 0, 0.12, 0.5, or 1.0 parts per million (ppm) ozone. Circumferential tension development was measured in isolated airways in response to bethanechol, acetylcholine, and electrical field stimulation. Responsiveness of the airways to the contractile stimuli was described by the effective dose or frequency that elicited half-maximum contraction (ED50) and the maximum response. Since ozone exposure is associated with remodeling of peripheral airways, smooth muscle area was determined and tension responses were normalized to the area measurements. Before normalization of tension data to smooth muscle area, neither the ED50 nor maximum response of small bronchi to the contractile stimuli was altered after chronic ozone exposure. Smooth muscle area was greater in airways isolated from animals that had been exposed to 0.5 ppm ozone. After accounting for smooth muscle area, maximum responses of the small bronchi isolated from male rats were significantly reduced after 0.12 and 0.5 ppm ozone. Although not significant statistically, a similar trend was observed in airways isolated from female rats. These results suggest that the increase in airway responsiveness associated with acute ozone exposure does not persist during near-lifetime exposure. Although the mechanism responsible for the adaptation to the effects of O3 on airway responsiveness is unknown, the results indicate that smooth muscle cell function was compromised by the chronic exposure. The mechanism(s) responsible for mediating this effect and the relevance of these results to humans remains to be determined.

Adaptation, Physiological↗
PubMed1995

Mechanisms of 5-hydroxytryptamine-induced contraction of isolated rat intrapulmonary bronchi.

Previous studies in our laboratory and others suggested that activation of 5-HT2 receptors mediates 5-hydroxytryptamine (5-HT)-induced contraction of airway smooth muscle and that this response is dependent in part on endogenous acetylcholine (ACh). The purpose of the present study was to confirm a role for 5-HT2 receptors and endogenous ACh in 5-HT-induced contraction of rat bronchi. In this study, we examined the effects of 5-HT2 receptor antagonists (ketanserin and LY53857), acetylcholinesterase inhibitors (physostigmine and neostigmine), and a muscarinic receptor alkylating agent [propylbenzilylcholine mustard (PBCM)] on contractile responses evoked by 5-HT and the 5-HT2 receptor agonist, alpha-methyl-5-hydroxytryptamine (alpha-Me-5-HT). Concentration-response curves generated in isolated rat intrapulmonary bronchi in response to 5-HT and alpha-Me-5-HT were superimposable. Inhibition of acetylcholinesterase by physostigmine or neostigmine potentiated contractile responses elicited by 5-HT and alpha-Me-5-HT. Alkylation of muscarinic receptors with PBCM decreased maximal responses elicited by 5-HT or alpha-Me-5-HT in a concentration-dependent manner. Maximum contraction attained with exogenous ACh was decreased by PBCM in a concentration-dependent manner and, at the highest concentration evaluated, ACh-induced contractions were abolished. 5-Hydroxytryptamine-induced contraction was inhibited competitively by low concentrations of the 5-HT2-receptor selective antagonist, ketanserin; higher concentrations abolished contractile responses to the amine. The inhibition of 5-HT-induced contractile responses by another 5-HT2-receptor selective antagonist, LY53857, was non-competitive in nature. Together, the results suggest that 5-HT contracts rat airways directly by activating 5-HT2 receptors located on airway smooth muscle and indirectly by activation of 5-HT2 receptors on parasympathetic nerve endings to cause release of ACh. The potential physiological implication of these findings is that 5-HT released in inflammatory conditions such as asthma may play a role in causing bronchoconstriction by releasing ACh or by augmenting release of ACh from activated cholinergic nerves.

Analysis of Variance↗
PubMed1985

Reflex partitioning of inputs from stretch receptors of bronchi and thoracic trachea.

A selective block of slowly adapting stretch receptors in anesthetized rabbits was induced by exposing to SO2 all thoracic airways (T) or the carina and bronchi alone (B). Increment of inspiratory time (TI) relative to control was 61% greater under B than T. The reverse would have happened if input responsible for Breuer-Hering inflation reflex originated from both bronchi and trachea. Hence, bronchial input activates inspiratory off-switch, while tracheal input delays its activation. During single inspiratory efforts with airways closed at end expiration diaphragm activity (Adi) decreased and TI0 increased relative to control equally under B and T. Hence, the input facilitating central inspiratory activity at end expiratory volume does not stem from trachea. At end of inspiratory ramp Adi stopped within 43 msec at control and 57 msec under B and T. Hence, bronchial input speeds up off-switching of inspiration. Postinspiratory Adi was greater under B than T, and nearly nil at control. Hence, bronchial input inhibits postinspiratory Adi, while tracheal input facilitates it. Inspiratory and expiratory flows were more damped under B than T, and under T than at control.

Animals↗
PubMed1984

Spontaneous and provoked resistance to isoproterenol in isolated human bronchi.

Cumulative concentration-response curves to isoproterenol were constructed in 74 preparations of human airways (group A) contracted with acetylcholine (80% of maximal contraction). In 52 bronchi (group A1), the maximal relaxation to isoproterenol represented at least 70% of the acetylcholine contraction (average 98% +/- 3) and the mean concentration (+/- SD) causing 50% of the relaxation (EC50) was 6.0 X 10(-8)M +/- 0.8. Resistance to isoproterenol (significant decrease of the maximal relaxation and right shift of the concentration-response curve) was provoked in 25 preparations by incubating them with isoproterenol (concentration 100 times higher than the individual EC50) for 30 min. The response to isoproterenol remained stable over the same time interval in eight control preparations. Incubation with isoproterenol did not modify the relaxing response to theophylline (n = 8). Indomethacin had no effect on the resistance provoked by isoproterenol incubation (n = 11). Incomplete relaxation to isoproterenol (maximal relaxation averaging 47% +/- 2 of the acetylcholine contraction) was observed in 22 preparations (group A2; mean EC50 = 1 X 10(-6)M +/- 0.2, significantly different [p less than 0.001] from group A1). Such preparations could be completely relaxed by theophylline (n = 7). For the whole group A, a significant negative correlation was found between isoproterenol EC50 and the magnitude of the maximal relaxation to isoproterenol (expressed as percent of acetylcholine contraction). There was no significant correlation between acetylcholine EC50 and isoproterenol maximum relaxation. Spontaneous resistance to isoproterenol was neither related to the technique of isoproterenol administration (cumulative versus noncumulative; n = 11) nor the magnitude of acetylcholine contraction (70% and 95% of maximal contraction; 14 bronchi, group B).

Airway Resistance↗