Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BRONCHUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources

Neurokinin A with K+ channel blockade potentiates contraction to electrical stimulation in human bronchus.

This study investigated the effects of neurokinin A (NKA) on cholinergic neural responses in human bronchus. NKA (0.1 nM) did not alter the contractile response to submaximal electrical field stimulation. However, K+ channel blockade with 4-aminopyridine (4-AP) (0.1 mM) potentiated the response to electrical field stimulation (to 182 +/- 25% of control, n = 4, P less than 0.05) and subsequent addition of NKA in the presence of 4-AP produced further potentiation (to 123 +/- 6% of the response to 4-AP n = 4, P less than 0.05). Neither 4-AP (0.01 or 0.1 mM) nor NKA in the presence of 4-AP potentiated the actions of exogenous acetylcholine but in these experiments 4-AP itself produced a marked direct contractile response. Thus NKA in the presence of K+ channel blockade potentiates cholinergic neural response in human bronchus and this occurs at a prejunctional site.

4-Aminopyridine↗

Receptors for neurokinins in human bronchus and urinary bladder are of the NK-2 type.

Human tissues such as the isolated bronchus and urinary bladder respond to neurokinins with concentration-dependent contractions, which appear to be due to the activation of receptors. We characterized these receptors in the present study using agonists (the naturally occurring neurokinins and some selective agonists) as well as newly identified antagonists. The order of potency of the agonists in the two preparations was as follows: neurokinin A (NKA) greater than substance P (SP) greater than neurokinin B (NKB) (bronchus) and NKA greater than NKB greater than SP (bladder), which suggests the presence of NK-2 receptors. This was confirmed by data obtained with two antagonists, one of which was shown to be competitive and selective for NK-2 type receptors. It thus appears that receptors of the NK-2 type are present in humans along the tracheo-bronchial tree and in the urinary system.

Bronchi↗

Glycosaminoglycans in the bronchial mucus of patients with chronic bronchitis and mucoid impaction of the bronchus.

Glycosaminoglycans were isolated from mucus of patients with chronic bronchitis and mucoid impaction of the bronchus, whose contents were approximately 56 mumoles and 80 mumoles of hexosamine per g of dry weight of mucus respectively. Electrophoretic and chemical characterization and enzymatic susceptibility demonstrated that the glycosaminoglycans in mucus from both groups of the patients contained hyaluronic acid as the main constituent, with undersulphated chondroitin as a minor component. In addition, in mucus from the patient with mucoid impaction of the bronchus chondroitin sulphate and heparan sulphate or heparan sulphate-like substance were identified.

Adult↗

Pre-junctional inhibitory action of prostaglandin E2 on excitatory neuro-effector transmission in the human bronchus.

The effects of prostaglandin E2 (PGE2) and indomethacin on excitatory neuro-effector transmission in the human bronchus were investigated by tension recording and microelectrode methods. PGE2 (10(-10)-10(-9)M) suppressed the amplitude of twitch contractions and excitatory junction potentials (e.j.ps) evoked by field stimulation at a steady level of basal tension obtained by the combined application of indomethacin (10(-5) M) and FPL55712 (10(-6) M). In doses over 10(-8)M, PGE2 reduced the muscle tone and dose-dependently suppressed the amplitude of twitch contractions. Indomethacin (10(-5) or 5 x 10(-5) M) reduced the muscle tone and enhanced the amplitude of twitch contractions and e.j.ps evoked by field stimulation in the presence of FPL55712. PGE2 (10(-9) M) had no effect on the post-junctional response of smooth muscle cells to exogenously applied acetylcholine (ACh) (4 x 10(-7) M). However, indomethacin (10(-5) M) significantly enhanced the ACh-induced contraction of the human bronchus. These results indicate that PGE2 in low concentrations has a pre-junctional action to inhibit excitatory neuro-effector transmission in addition to a post-junctional action, presumably by suppressing transmitter release from the vagus nerve terminals in the human bronchial tissues.

Bronchi↗

Neuropeptide gamma, the most potent contractile tachykinin in human isolated bronchus, acts via a 'non-classical' NK2 receptor.

Cumulative contractile response curves to neurokinin A (NKA) and neuropeptide gamma (NP gamma) were obtained in human isolated bronchus, in the presence of phosphoramidon 10 microM. NP gamma was approximately 10-fold more potent than NKA (pD2 values 8.6 +/- 0.4 and 7.3 +/- 0.3 respectively, n = 6; P less than 0.01). The NK1-selective agonist [Sar9, Met(O2)11]-SP and the NK3 selective agonist senktide produced negligible contraction. Response curves to NP gamma and NKA were unaffected by the NK2 subtype-selective antagonist MDL 29913 at 2 microM, but NP gamma-induced contraction was markedly inhibited by 20 microM MDL 29,913. Thus NP gamma is the most potent tachykinin in human isolated bronchus and its effects are mediated at a receptor which is not of the 'classical' NK2 subtype found in hamster urinary bladder.

Amino Acid Sequence↗

Development of bronchus associated lymphoid tissue (BALT) in the rat, with special reference to T- and B-cells.

The development of bronchus associated lymphoid tissue was studied in normal rats, in serial sections, using both routine histological techniques and the two-step immuno-peroxidase method on cryostat sections for demonstration of T lymphocytes, IgM-, IgG- and IgA-bearing B lymphocytes and plasma cells, respectively. BALT first appears 4 days postpartum (p.p.) as a condensation of reticulum cells near a lymph vessel, between the main bronchus and the accompanying artery. Only a few lymphocytes are present at first. Vascularisation is considerable 8 days p.p. and includes high endothelial venules. Leucocytes are seen in transit in both blood- and lymph vessel walls. Lymphocytes populate the area under the epithelium from about 2 weeks p.p. A few IgM, IgG- and IgA-bearing B cells are already present at 4 days, and rapidly increase in numbers; T cells usually appear at day 8. Discrete T- and B-cell areas do not appear until 4 weeks and are only observed regularly after 12 weeks, when secondary follicles appear. BALT starts development at a similar time to other peripheral lymphoid organs but apparently achieves immunological activity later. It is concluded that antigens probably play an important part in organising BALT.

Age Factors↗

Computed tomographic demonstration of displaced right upper lobe bronchus in an adult woman with congenital heart disease.

To our knowledge, this is the first description of the computed tomographic appearance of a displaced right upper lobe bronchus. The case reported is that of a 43 year-old woman who had known congenital heart disease and systemic hypertension. The computed tomographic study demonstrated a displaced right upper lobe bronchus; a persistent left superior vena cava; pulmonary hypertension with associated dilatation of the right chambers of the heart consistent with a longstanding left to right shunt; and subsequent development of pulmonary hypertension.

Abnormalities, Multiple↗

Comparative metabolism and macromolecular binding of benzo[a]pyrene in explant cultures of human bladder, skin, bronchus and esophagus from eight individuals.

Benzo[a]pyrene (B[a]P) metabolism and macromolecular binding have been studied in explants from 4 tissues, bladder, skin, bronchus and esophagus from 8 donors sampled within 4 h after death. Explants were incubated with [3H]benzo[a]pyrene for 24 h, then the metabolites extracted and analyzed by high-pressure liquid chromatography. Fibroblasts were grown from explants from 2 patients and also incubated with B[a]P. Metabolite profiles were qualitatively the same for explants and fibroblasts with similar product ratios, although fibroblasts were less active in B[a]P metabolism. DNA binding studies showed a broad variance between patients and tissues with the relative distribution being widest in bladder, followed by skin, bronchus and esophagus, respectively.

Benzopyrenes↗

Pilot studies of superfractionated radiotherapy and combination chemotherapy in limited oat cell carcinoma of the bronchus.

There are sound radiobiologic and suggestive clinical rationale for superfractionating the radiotherapeutic regimens employed for the therapy of rapidly growing malignancies. Oat cell carcinoma of the bronchus is such a tumor. We report our experience combining aggressive systemic combination chemotherapy with superfractionated radiotherapy for the treatment of "limited" oat cell carcinoma of the bronchus. Overall, patient tolerance was satisfactory and a complete remission rate of 74% was achieved. It remains to be proven, in a prospective randomized fashion, whether this approach is superior to current conventional management.

Adult↗

Inadvertent intubation of the left mainstem bronchus.

This is a case report of a previously healthy 61-year-old white male who was emergently intubated in the field by paramedical personnel and transported to the emergency department. Physical examination revealed minimal-to-absent breath sounds over the right hemithorax associated with cyanosis of the head, face, and upper extremities. Emergency needle decompression of the right lung was accomplished without improvement. A postmortem chest radiograph revealed a left mainstem bronchus intubation. Use of the physical examination, the endotracheal tube depth, and an awareness of the possible--but rare-complication of left mainstem bronchus intubation may lead to accurate diagnosis and treatment and avoid unnecessary procedures.

Aortic Rupture↗

Compression of trachea and left main bronchus by arch aneurysm.

We report on the case of a 70-year-old woman who presented dyspnea. Contrast-enhanced computed tomography of the chest revealed the compression of the lower part of the trachea and left main bronchus by an aneurysm of the ascending aorta and aortic arch. Although we performed a replacement of the ascending aorta and aortic arch, we were unable to relieve the stenosis of the trachea and bronchus. By the suspension of the posterior wall of the native aneurysm, we were able to successfully relieve the compression and alleviate the respiratory insufficiency.

Aged↗

Resection of the entire left mainstem bronchus for an inflammatory pseudotumor.

We present the case of a 16-year-old white girl with a history of recurrent postobstructive pneumonia. Chest roentgenogram, chest computed tomography, and bronchoscopy revealed a mass in the left mainstem bronchus with an exophytic component. Multiple bronchoscopic biopsies confirmed the mass to be an inflammatory pseudotumor. After failing months of medical therapy with systemic steroids as well as several laser ablations, the tumor was removed through a left thoracotomy with resection of the entire left mainstem bronchus and reimplantation of the left upper and lower lobe into the trachea without complication or recurrence after 1 year.

Adolescent↗

Right upper lobe venous drainage posterior to the bronchus intermedius: preoperative identification by computed tomography.

BACKGROUND: Anatomical variations of the pulmonary vessels relevant to pulmonary surgery are of concern to thoracic surgeons. Among such variations, the right upper lobe vein posterior to the bronchus intermedius (UVPBI) has received little attention thus far. METHODS: Chest computed tomographic images and medical records of 725 patients were retrospectively reviewed. The frequency, drainage pattern, diameter, and associated anatomical characteristics of the UVPBI were assessed, and our right thoracotomy cases with the UVPBI were examined. RESULTS: The UVPBI was found in 41 (5.7%) of 725 computed tomography cases, and in 9 (3.9%) of 230 right thoracotomy cases. Three UVPBI drainage sites were observed: (1) the superior pulmonary vein group, 55%; (2) the inferior pulmonary vein group, 41%; and (3) the superior segmental vein group, 4%. The diameter of the UVPBI at the level of the bronchus intermedius ranged from 1 to 7 mm (4.1 +/- 1.6 mm). The diameter of the UVPBI in the superior pulmonary vein group was significantly greater than that in the inferior pulmonary vein group (p < 0.01). The prevalence of a central vein was 43.9% for all UVPBI cases and 15.8% for large UVPBI cases (> or = 5 mm in diameter). Of the 9 right thoracotomy patients, 1 suffered UVPBI injury; this patient's UVPBI was not identified either preoperatively or intraoperatively. CONCLUSIONS: The UVPBI is not as rare as was previously believed. It can be a main drainage route of the right upper lobe. Preoperative identification of this venous variation by computed tomography is useful for safe and accurate surgical procedures.

Adult↗

Abnormal modulation of cholinergic neurotransmission by endomorphin 1 and endomorphin 2 in isolated bronchus of type 1 diabetic rats.

To assess whether diabetes alters the regulatory effects of mu-opioid receptor (MOR) agonists on the cholinergic bronchoconstriction, we investigated the inhibitory effects of endomorphins (EMs) on the electrical field stimulation (EFS)-induced cholinergic bronchoconstriction in type 1 diabetic rats. At 4 weeks after the onset of diabetes, both the EFS- and exogenous acetylcholine (ACh)-induced bronchoconstriction in diabetes in vitro were greater than those in non-diabetes rats. Furthermore, endomorphin 1 (EM1) and endomorphin 2 (EM2) inhibited the response to EFS in diabetic rat isolated bronchus in a concentration- and frequency-dependent manner, which is in agreement with that in non-diabetes. However, the inhibitory effects of EMs on the EFS-induced bronchoconstriction in diabetes were significantly weaker than those in non-diabetes. Both EM1 and EM2 (1 microM) had no effect on the contractile response to exogenous ACh, indicating a prejunctional effect. Furthermore, the inhibitory effect on the EFS-induced bronchoconstriction was blocked by naloxone (10 microM). Eight weeks after the induction of diabetes, both the EFS- and exogenous ACh-induced bronchoconstrictions in diabetes were further enhanced compared to those in short-time (4 weeks) diabetic rats. Moreover, the inhibitory effects of EMs on the EFS-induced bronchoconstriction were further attenuated. These results suggest that dysfunction of presynaptic inhibitory modulation through opioid receptor by EMs may take place in the bronchus of diabetic rats.

Acetylcholine↗

Christmas surprise: the unnoticed journey of a needle-from bronchus to intestine.

We report on a 14-year-old Arabian girl who suddenly developed coughing after having aspirated a needle used for fixing her headscarf. The chest X-ray showed the needle located in the right main bronchus. However, subsequent flexible bronchoscopy could not detect any foreign body. A further X-ray of the abdomen showed the needle now behind the diaphragm. Gastro-oesophageal endoscopy was also uneventful. On the third day, the needle was excreted naturally. Astonishingly, this journey of the wandering needle from bronchus to intestine was not realised by the patient at any time. Our case highlights that children and adolescents should be warned repeatedly about the risks of putting needles between their teeth. It also reminds the physician to diagnose aspirated foreign bodies as early as possible to prevent wandering and migrating, which may induce new risks and unnecessary diagnostic and therapeutic procedures.

Adolescent↗

Experimental tracheal reconstruction with a rotated right stem bronchus.

BACKGROUND: To reconstruct a longer tracheal defect, a safe method other than end-to-end anastomosis is necessary. METHODS: Nine mongrel dogs underwent right thoracotomy. The lobes of the right lung other than the apical lobe were resected, keeping the bronchi in place to be manipulated to extend the right stem bronchial conduit. The trachea was resected for a 10-cartilage-ring length. The modified right stem bronchus was then brought into the mediastinum by rotation in the frontal plane. An end-to-end anastomosis was made. The right apical lobe, once separated, was then reanastomosed end-to-side. Ciliary transport was studied. RESULTS: Eight of the 9 dogs tolerated the surgical procedure well, and the reanastomosed right apical lobe remained well expanded for 1 year or more postoperatively. The inverted segment did not show any cranial ciliary transport movement. CONCLUSIONS: A large tracheal defect more than 10 rings in length can be reconstructed using a rotated right stem bronchus with the right apical lobe reanastomosed. The inverted bronchial segment loses its cranial ciliary transport movement.

Anastomosis, Surgical↗

Bronchial carcinoid of an accessory tracheal bronchus.

We present a rare case of bronchial carcinoid tumor arising in an accessory right tracheal bronchus and involving the associated tracheal lobe in a 48-year-old man, who presented with a history of recurrent respiratory infections and recent onset of hemoptysis. Diagnosis was established on preoperative bronchoscopy and biopsy. The tumor was completely removed by right upper lobectomy with the tracheal bronchus resected flush to its origin from the right lower tracheal wall. Final histology revealed a typical carcinoid tumor.

Abnormalities, Multiple↗

Management of the irradiated bronchus after lobectomy for lung cancer.

BACKGROUND: Radiation effects make operative dissection difficult, impair subsequent healing, and increase morbidity. This study evaluates tissue reinforcement of the irradiated bronchus as a modality to reduce morbidity after lobectomy for lung cancer. METHODS: We retrospectively reviewed all patients who had preoperative radiotherapy before lobectomy for lung cancer between May 1977 and June 2000. RESULTS: There were 56 patients (33 men and 23 women) who ranged in age from 42 to 80 years (median, 59 years). Bronchial stump reinforcement included no coverage in 24 patients (42.8%), mediastinal tissue (parietal pleura, pericardial fat, or azygos vein) in 16 (28.6%), and muscle (serratus anterior) in 16 (28.6%). Median preoperative radiation dose was 4,600 cGy (range, 3,000 to 9,810 cGy) and did not differ between the groups. There were three deaths (13%) in the no coverage group, one (6%) in the mediastinal tissue group, and one (6%) in the muscle group (NS). Pulmonary complication rate was 67% in the no coverage group, 44% in the mediastinal group, and 25% in the muscle group (p = 0.03). Median duration of chest tube drainage was 8 days in the no coverage group, 6 days in the mediastinal group, and 5 days in the muscle group (p = 0.006). Median hospital stay was 13 days in the no coverage group, 9 days in the mediastinal group, and 7 days in the muscle group (p = 0.02). Patients in the muscle group had reduced hospital stay, duration of chest tube drainage, and pulmonary complications compared with the other two groups (p < 0.05). Subjectively, presence and magnitude of postoperative pain, range of motion, and strength of the upper extremity of the muscle flap side were not different between the groups (p = NS). Follow-up was complete and ranged from 4 to 147 months (median, 17 months). CONCLUSIONS: Tissue reinforcement of the irradiated bronchus after lobectomy reduces postoperative morbidity and hospitalization. Transposition muscle flap may be preferred.

Adult↗