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At least 775 records · Page 43Linked to original sources
PubMed1995

Effect of nitric oxide on in vitro responsiveness of bovine bronchus and pulmonary vessels.

Experiments were conducted in bovine isolated bronchi and pulmonary vessels to test whether nitric oxide (NO) could reduce carbachol and hypoxia or KCl (120 mM) induced contraction. Segments of bronchus or pulmonary vessels were slipped around a water-filled balloon connected to a pressure transducer, and mounted in 3 ml thermostated chamber filled with Krebs-Henseleit solution equilibrated with different gas mixtures. NO-CO2-N2 mixtures containing 10, 50 or 100 ppm NO were prepared. The effect of methylene blue on intrinsic tone and the bias effect of residual red blood cells were assessed. The results demonstrate that NO has no obvious effect on the intrinsic tone, the force generated by carbachol stimulation, or the spontaneous relaxation after removal of carbachol, in bronchi, with the exception of 100 ppm which increased the relaxing rate in small bronchi. By contrast, 50 and 100 ppm NO caused 53 and 61% decrease in the hypoxia-induced pulmonary arterial contraction, respectively. One hundred ppm NO caused 40, 38, 50 and 66% decrease in the KCl-induced contraction in pulmonary artery (PA), small pulmonary artery (SPA), small pulmonary vein (SPV) and pulmonary vein (PV), respectively. Sodium nitroprusside (10(-5) M) and isoproterenol (10(-5) M) reduced the carbachol-induced increase in bronchial pressure by 80% and nearly 100%, respectively. The residual concentration of haemoglobin in the chamber cannot explain the lack of effect of NO on the bronchi.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Inhibitory effect of tetrandrine on C fiber activation-induced contractions in trachea and bronchus of guinea pig.

AIM: To study the inhibitory effects of tetrandrine (Tet) on an activation of the sensory nervous C fibers in isolated trachea and bronchus of guinea pig. METHOD: The electric field stimulation induced a phase II contraction of the preparations, which was due to an activation of the C fifers. The effects of Tet on phase II contraction were analyzed. RESULTS: Tet 0.3-30 mumol.L(-1) inhibited phase II contractions in a concentration-dependent manner. That phase II contractions inhibited by Tet 1 mumol.L(-1) were 40 +/- 38% and 75 +/- 22% of control in tracheae and bronchi respectively. After pretreatment with chlorphenamine or atropine phase II contraction were still reduced by Tet 1 mumol.L(-1), inhibitory rates being 70 +/- 16% and 64 +/- 16% of control, respectively. The contractile responses of the preparations to exogenous substance P, however, were unaffected by treatment with Tet 1 mumol.L(-1). CONCLUSION: Tet 1 mumol.L(-1) inhibits phase II contraction, related to the inhibition of local release of neuropeptides from C fibers of guinea pig airway.

Alkaloids↗
PubMed1994

Pharmacological profiles of contractile endothelin receptors in guinea pig hilar bronchus.

Characterization of the receptors mediating contractions to endothelin-1 (ET-1), endothelin-3 (ET-3), sarafotoxin S6c (STXc), or IRL 1620 in isolated epithelium-denuded hilar bronchus of guinea pig using as antagonists BQ-123 (ETA receptor-selective) and Ro 46-2005 (ETA/B nonselective) was investigated. ET-1, ET-3, STXc, and IRL 1620 produced only contraction, and their concentration-response curves were obtained at the same concentration range (10(-10)-10(-7) M). The potency order was the following: STXc = ET-3 = ET-1 > IRL 1620. BQ-123 (10(-5)M) had no marked effect on the contraction induced by ET-3 or STXc, whereas it attenuated the response induced by high concentration of ET-1 (3 x 10(-8)-10(-7)M). The contraction induced by IRL 1620 was antagonized by BQ-123 (3 x 10(-6)-10(-5)M). Ro 46-2005 (10(-5)M) failed to inhibit the responses to ET-1 and ET-3. Ro 46-2005 (10(-5)M) slightly, but significantly, shifted the concentration-response curve for STXc to the right (pKB = 4.94 +/- 0.10, n = 7), and the maximum response was potentiated to about 127%. The curve for IRL 1620 was shifted in parallel by Ro 46-2005 (3 x 10(-6)-10(-5)M) to the right (mean pKB = 6.35 +/- 0.09, n = 8). These results suggest that ETB receptors primarily mediate contraction to ET-1, ET-3, STXc, and IRL 1620, and the relative inhibitory activities of ET antagonists vary with the agonist used. However, ET-1 and ET-3 might also activate non-ETB receptor or unknown mechanisms.

Animals↗
PubMed1994

Distribution of proliferating-cell nuclear antigen and epidermal growth factor receptor in intraepithelial squamous cell lesions of human bronchus.

Distribution of proliferating-cell nuclear antigen and epidermal growth-factor receptor was studied by immunohistochemistry in intraepithelial squamous cell lesions of human bronchus. Ten biopsy specimens were examined for each of the following categories of lesions (50 specimens altogether): normal bronchial epithelium, benign squamous metaplasia, dysplastic squamous metaplasia, and squamous cell carcinoma in situ, in addition to invasive squamous cell carcinoma. The percentage positivity of immunoreactive cells and their localization in the epithelium were examined in formalin-fixed, paraffin-embedded tissues of bronchial biopsy specimens retrieved from the surgical pathology file. Proliferating-cell nuclear antigen positivity ranged from 3.2% (normal bronchial epithelium), to 7.6% (benign squamous metaplasia), 51.8% (dysplastic squamous metaplasia), and 85.0% (squamous cell carcinoma in situ). The difference between the groups was statistically significant (p < 0.01). The percentage positivity for invasive squamous cell carcinoma was 56.9%. Epidermal growth-factor receptor positivity ranged from 7.3% (normal bronchial epithelium), to 38.7% (benign squamous epithelium), 67.5% (dysplastic squamous metaplasia), and 91.3% (squamous cell carcinoma in situ). The difference between the groups was statistically significant (p < 0.01). Invasive squamous cell carcinoma positivity was 49.7%. Both proliferating-cell nuclear antigen-positive and epidermal growth-factor receptor-positive cells showed zonal distribution in the bronchial epithelium. They were located in the basal cell layer in normal bronchial epithelium and expanded upward as the morphologic changes advanced. In squamous cell carcinoma in situ, both proliferating-cell nuclear antigen-positive and epidermal growth-factor receptor-positive cells covered the entire thickness of the bronchial epithelial layer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

The search for prejunctional inhibitory muscarinic receptors in human bronchus.

The purpose of our study was to search for and classify prejunctional inhibitory muscarinic receptors in human bronchus with a wide range of muscarinic antagonists. Human bronchial airway smooth muscle strips, collected at thoracotomy from 54 subjects, 31 patients with chronic airway obstruction and 23 control subjects, were suspended in organ baths and stimulated by electrical field stimulation. The stimulation parameters were: frequency: 32 Hz; Grass reading voltage: 70 V (voltage between the electrodes: 15 V); pulse duration: 0.5 msec and train duration: 10 sec, every minute. Twitch responses of smooth muscle strips of 27 subjects (14 with and 13 without chronic airway obstruction) were sufficiently stable to search for the effects of M1-, M2- and M3-selective antagonists. All antagonists were added to the bath in a cumulative manner and decreased twitch contraction. No convincing evidence was found for the presence of prejunctional inhibitory muscarinic receptors of the M2-subtype, reasons for this obvious absence are discussed. Anaesthetical drugs for example, may mask the prejunctional inhibitory muscarinic receptors. The question remains whether the used electrical field stimulation experiments are suitable to point out prejunctional inhibitory muscarinic receptors. It is concluded that additional experiments with other experimental methods and in patients with different anaesthetical treatment are needed.

Airway Obstruction↗
PubMed1994

[Incidence of nodal involvement of #12u nodes (lymph nodes around the upper lobe bronchus) in cases with right middle lobe, right lower lobe, and left lower lobe carcinoma].

#12u nodes are peribronchial lymph nodes around the upper lobe bronchus which should not be routinely dissected in cases with middle lobe carcinoma or lower lobe carcinoma. In this paper, #12u were examined histologically in 152 lung cancer cases. As a results, 14 of 152 (9.2%) had nodal diseases in #12 nodes. #12u nodes were involved in 3 of 30 N1 diseases (10%), and in 11 of 35 N2 diseases (31.4%). There was a case which had no nodal involvement except for #12u node. And in three cases, we found only one nodal metastasis except for #12u nodes. If we did not dissect #12u nodes, these cases will be relapse in near future. Thus, for curative operation, #12u nodes should be dissected as a standard operation.

Carcinoma, Non-Small-Cell Lung↗
PubMed1993

Malignant mixed tumor of bronchus: a biphasic neoplasm of epithelial and myoepithelial cells.

This paper describes an unusual malignant mixed tumor of the bronchus arising in a 71-yr-old male and provides evidence of an epithelial-myoepithelial origin based on the findings on light microscopy and immunohistochemistry. The neoplasm contained elements of recognizable benign tumor resembling salivary gland-type pleomorphic adenoma, adenosquamous carcinoma, and a spindle-cell sarcomatous component. Immunohistochemical stains showed the characteristic relationship between epithelial and myoepithelial cells in the benign component of the neoplasm. In addition, the spindle cells stained for myoepithelial markers (S-100 protein and actin) but were also positive for keratin (AE1/AE3). The relationship of this neoplasm to classical carcinosarcoma and the recently described adenosquamous carcinoma with amyloid-like stroma is discussed.

Adenocarcinoma↗
PubMed1993

[Cardiorespiratory changes induced in man by the acute occlusion of the main bronchus].

Following the exclusion of the ventilation of a lung, perfusion is arrested as a consequence of the Von Euler and Liljestrand vasoconstrictive reflex. However it is as yet unknown how long this phenomenon takes to manifest itself in human beings. In order to verify whether hypoxic pulmonary vasoconstriction follows immediately on the arrest of ventilation or whether there is one some delay, in 21 candidates for pneumonectomy a bronchial block was provoked during fibrobronchoscopy and the hemogasanalytic modifications induced by the acute occlusion of the main bronchus have been studied. The analysis of the resulting data allows for the hypothesis that the exclusion of lung ventilation for 14 minutes is not sufficient to cause the complete manifestation of the hypoxic vasoconstrictive reflex.

Aged↗
PubMedDate not supplied

Structure and development of bronchus-associated lymphoid tissue in conventionally reared broiler chickens.

The development of bronchus-associated lymphoid tissue (BALT) in conventionally reared broiler chickens of 1 day and 1, 2, 3, 4, 6, and 8 weeks of age was studied using light and electron microscopy (scanning and transmission). BALT in these chickens resembled other mucosa-associated lymphoid tissues (MALT) in that it was composed of an altered epithelium overlying a population of lymphocytes and contained potential antigen-presenting cells, such as macrophages and dendritic cells; high endothelial venules were also present. In contrast to other MALT, epithelial cells in chicken BALT were not of the M-cell type; i.e., they lacked large numbers of apical tubules and vesicles for specialized uptake of luminal antigens. There were age-related differences in size, number, and cellular composition of BALT nodules. Lymphoid nodules were progressively larger and more numerous with increasing age. Germinal centers were present in birds 2 weeks of age and older. BALT epithelium was primarily squamous and non-ciliated in 1-day and 1-week-old chicks, becoming progressively more columnar and ciliated in older chickens. Lymphocyte infiltration of the epithelium was extensive at 1 to 4 weeks of age; in older chickens, distinct epithelial and lymphocytic compartments were separated by connective tissue.

Animals↗
PubMed1995

Characterization of the endothelin-converting enzyme in guinea pig upper bronchus.

We studied the pharmacologic effects of big endothelin-1 (big ET-1), big endothelin-2 (big ET-2), and big endothelin-3 (big ET-3), and characterized the enzyme involved in the conversion of the three peptides in guinea pig upper bronchus (GPUB). ET-1, ET-2 and ET-3 (0.1-300 nM) elicited similar concentration-dependent contractions of GPUB. Big ET-1 and big ET-2, but not big ET-3, also elicited potent concentration-dependent contractions of GPUB. The conversion of big ET-1 to ET-1 in the GPUB is sensitive to phosphoramidon but not to thiorphan or captopril. Phosphoramidon inhibited the conversion of big ET-2 to ET-2, thiorphan had minimal effect, and captopril was without effect. These results suggest that the putative endothelin-converting enzyme (ECE) is involved in the conversion of big ET-1 to ET-1 in GPUB and the conversion of big ET-2 to ET-2 by a nonselective enzymatic process.

Animals↗
PubMed1996

Third complementarity determining region sequence analysis of low-grade bronchus-associated lymphoid tissue lymphoma: genotypic analysis reveals heterogeneity in maturation.

It has recently been suggested that autoimmunity may play a role in the pathogenesis of low-grade mucosa-associated lymphoid tissue lymphomas, but precise genotypic analysis of antigen binding sites of low-grade bronchus-associated lymphoid tissue (BALT) lymphomas has not been reported. We analyzed the third complementarity determining region (CDR3) in eight cases of low-grade BALT lymphoma by 2-step PCR and sequencing analysis. All cases showed a distinct monoclonal band (about 100 base pairs) on electrophoresis. In seven cases, a single major CDR3 sequence was identified with five to nine clones among 10 vector clones being identical; and in the remaining case, two major sequences were obtained, with four clones among nine vector clones being identical. Findings suggestive of the autoimmunity of low-grade BALT lymphoma were obtained: (1) VHDJH rearrangements in seven of the eight lymphoma cell clones were potentially functional; (2) genotypically, two lymphoma cell clones showed 60 to 74% homology with G6 positive lymphocyte clones; and (3) five lymphoma cell clones showed 61 to 71 % homology with lymphocyte clones derived from fetal liver or cord blood. In one case, the N-D-N length of the neoplastic clone was very short and lacked N nucleotides at the D-JH junction. Therefore, our study demonstrates genotypic heterogeneity in maturation in low-grade BALT lymphoma.

Adult↗
PubMed1996

[A successful surgical case of descending necrotizing mediastinitis with fistula formation to the right main bronchus].

Descending necrotizing mediastinitis (DNM) is extremely rare and one of the most lethal forms of mediastinitis, even in the era of antibiotics. We have recently treated a 65-year-old man who was diagnosed as having a fistula to the right main bronchus caused by DNM secondary to a peritonsillar abscess. Surgical treatment consisted in closing the right bronchial fistula and covering it with the latissimus dorsi muscle flap and mediastinal drainage through thoracotomy. Postoperative course was uneventful. This is the second known reported case of a successful operation for DNM with bronchial fistula.

Aged↗
PubMed1996

Evaluation of a simple technique for rapid access to left main bronchus.

A suction catheter with dual curvature at its tip was evaluated for its successful rapid access to left main bronchus. The catheter with dual curvature was passed through endotracheal tube in neutral position of head in 58 adult patients of both sexes in need of mechanical ventilation. Bedside x-ray (AP view) chest was taken to confirm its location. It is observed that this suction catheter had very high success rate of 95% in first attempt and 100% after repositioning endothracheal tube. It did not require any position alteration of head or body and easily allowed aspiration from left lung.

Adult↗
PubMedDate not supplied

[Undiagnosed bronchus carcinomas as the cause of sudden and unexpected fatalities].

Cases of sudden death accompanied by impressive external bleeding may arouse suspicion of violence. On the other hand fatal hemorrhages from the respiratory tract can be caused by injuries as well as by diseases. In the age of successfully treated tuberculosis the majority of pulmonary hemorrhages is based on bronchogenic carcinomas. Examples of fatal bleeding from malignant tumours of the bronchus show the variety of morphological substrates giving rise to these hemorrhages: e.g. aneurysma-like dissection of pulmonary arteries infiltrated by bronchogenic carcinoma, leukocytoclastic destruction of vessel walls surrounded by tumour necrosis, and arrosion of small arteries in the tumour region which leads to massive hemorrhage owing to anticoagulant therapy.

Adult↗
PubMed1998

Nociceptin-induced inhibition of tachykinergic neurotransmission in guinea pig bronchus.

Nociceptin is a novel neuropeptide of the opioid peptide family recently identified as the endogenous ligand of the opioid receptor-like "orphan" receptor. Unlike other opioids, nociceptin has hyperalgesic effects in vivo. In the present study, nociceptin was found to inhibit electrical field stimulation-induced tachykinergic contractions of the guinea pig isolated bronchus preparation. The threshold effect was about 1 nM, and at 0.1 microM, nociceptin inhibited contractions evoked by 5-Hz stimulation by more than 50%. This inhibitory effect was found to be mediated by a prejunctional mechanism involving none of the classical (mu, delta and kappa) opioid receptors. Although the hypothesis that the effect of nociceptin was secondary to opioid receptor-like stimulation cannot be pharmacologically addressed, opioid receptor-like-receptor-mRNA was found to be expressed in the upper vagal sensory ganglion, where the cell bodies of the tachykinin-containing sensory neurons are located. Nociceptin immunoreactive nerve fibers in the airway wall, distinct from the tachykinin-containing fibers, were identified as an endogenous source of nociceptin. These data indicate that nociceptin may influence airway physiology by modulating tachykinergic neurotransmission.

Animals↗
PubMed1998

[Rupture of the trachea and main bronchus after intubation].

The authors present two cases of post-intubation perforation of the trachea and main left bronchus resp. One was diagnosed incidentally during thoracotomy, on the second to third day after attempted intubation during which perforation occurred. The patient's life was threatened by the development of ARDS syndrome. The authors emphasize therefore the necessity of acute tracheobronchoscopy when perforation of the major airways during difficult intubation is suspected. Uncertain suture of the pars membranacea should be covered by the oesophagus.

Bronchi↗
PubMed1998

[A case of left main bronchus obstruction due to recurrent esophageal cancer successfully treated by Nd-YAG laser followed by radiotherapy, low-dose CDDP and continuous infusion of 5-FU].

A 63-year-old female patient with obstruction of left main bronchus due to recurrent esophageal cancer was treated by emergency Nd-YAG laser therapy under bronchoscopy. Severe dyspnea subsided dramatically and she was the given radiotherapy with a total dose of 50 Gy (2 Gy/f and 25 f/5 wks). Concurrent chemotherapy was performed at the 3rd week of radiation therapy. In this chemotherapy of CDDP plus 5-FU, CDDP (10 mg/day) was given for 5 days by intravenous and 5-FU (500 mg/day) for 5 days by continuous infusion the same week. By this treatment, a partial response (PR) was obtained, and the patient returned to normal life. But after 4 months, she had a recurrent lesion at the same place, and underwent only palliative laser therapy. Nd-YAG laser therapy for obstructive lesion of trachea due to recurrent cancer is the most useful one, but some subsequent treatment is required.

Antineoplastic Combined Chemotherapy Protocols↗