Biochemical and Ultrastructural Study on Bronchial Carcinoids

The biochemical and ultrastructural findings in 6 patients affected by bronchial carcinoid formed the basis of this study of the relationship between the morphology and the function of this tumor. The following conclusions are drawn: 1) the «secretion granules » observed under the electron microscope vary in number according to the cell age of the tumor; 2) it is confirmed that the diagnosis of bronchial carcinoid is based on the histological data obtained under the light microscope and in some cases may be confirmed either by electron microscope or biochemical studies; 3) the morphofunctional study of the tumor should allow classification of the different stages of bronchial carcinoid.

Neutral and acidic human tracheobronchial mucin. Isolation and characterization of core protein

Human bronchial mucin from a patient suffering from chronic bronchitis was solubilized in aqueous solution containing sodium azide and protease inhibitors and purified by Sepharose 4B and 2B column chromatography. The mucin was further purified by cesium bromide density gradient centrifugation. Sodium dodecyl sulfate-polyacrylamide gel (7.5%) electrophoresis of this material showed high-molecular-weight mucin component(s) at the top of the gel. Chemical analysis of this preparation indicated a typical mucin profile of amino acids and carbohydrates. Ion-exchange chromatography resulted in resolution of the purified mucin into neutral and acidic fractions. Comparison of the chemical composition of these two fractions showed higher mole percentage of threonine, serine, sialic acid, and sulfate in the acidic fraction. Chemical deglycosylation of the purified mucin preparation with trifluoromethane sulfonic acid was carried out at 20 degrees C for 3 1/2 h. Sialic acid, fucose, galactose, and N-acetylglucosamine were completely removed, whereas traces of N-acetylgalactosamine were still detected. High-pressure liquid chromatography of the deglycosylated products from native, neutral, and acidic mucin preparations resulted in a principal peptide, P1, with identical amino acid composition. Cyanogen bromide (CNBr) treatment of the peptide P1 from neutral and acidic mucins and subsequent fractionation of the fragments by high-pressure liquid chromatography resulted in similar peptide profiles. The P1 peptide fraction was further subjected to high-pressure liquid chromatography in a second solvent system, which resulted in two peaks, P1a and P1b. Gel filtration of both peptides in 6 M guanidine hydrochloride indicated a single peak with molecular weight of approximately 97 kDa. The amino acid profile of the two peptides was dominated by high levels of threonine, serine, and proline, which combined accounted for nearly 39% of the total residues, and in most respects, the profile resembled that of native mucin. End-group analysis of the peptide P1a indicated a blocked N-terminus, whereas serine was found to be the N-terminal amino acid in the peptide P1b. Rabbit antibodies prepared against the peptide P1 from native tracheal mucin reacted strongly with neutral and acidic mucin as well as the mucin from human colon. Both neutral and acidic human tracheal mucins were immunologically reactive with mouse monoclonal antibody HMPFG-2, which was prepared against human mammary mucin. However, the response of this antibody to human colonic mucin was rather weak.

Evidence of hydrophobic domains in human respiratory mucins. Effect of sodium chloride on hydrophobic binding properties

Hydrophobic binding properties of purified human respiratory mucins were studied by the fluorescence probe technique using mansylphenylalanine (Mns-Phe) as the fluorescent probe. Mucins were purified from tracheobronchial secretions of cystic fibrosis (CF) and asthmatic patients, as well as from individuals with normal lungs, according to a protocol earlier established in our laboratory. Purified mucins were subjected to reduction-alkylation and Pronase digestion to study the effects of these treatments on the hydrophobic properties of the mucins. In addition, the effects of increased NaCl concentration on the hydrophobic properties of native and reduced-alkylated mucins were also investigated. Native mucins showed evidence of a large number of low-affinity (KD approximately 10(-5) M) binding sites for the hydrophobic ligand Mns-Phe and had between 40 and 50 binding sites/mg of mucin. Reduction of mucin using dithiothreitol in the presence of 6 M guanidine hydrochloride and subsequent alkylation with iodoacetamide apparently caused marked conformational changes in the mucin molecules as revealed by the presence of both high-affinity (KD approximately 10(-6) M) and low-affinity (KD approximately 10(-5) M) binding sites for the probe and an increase in the number of probe binding sites. Pronase digestion of the native and reduced-alkylated mucins almost completely eliminated binding of the fluorescent probe to the mucins, showing that the binding sites are on the nonglycosylated, Pronase-sensitive portion of the mucin molecules. Increasing NaCl concentrations (0.03-1.0 M) did not appreciably alter the native mucin-induced Mns-Phe fluorescence, while that of the reduced-alkylated mucin-induced Mns-Phe fluorescence was progressively increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Concentrations of cefixime in bronchial mucosa and sputum after three oral multiple dose regimens

In a study of 58 patients the concentrations of cefixime, a new oral cephem antibiotic, in bronchial mucosa were 35-40% of the concentrations found in simultaneously collected serum samples. The antibiotic was often undetectable in sputum despite a highly sensitive assay.

Distribution of substance P receptors in rabbit airways, functional and autoradiographic studies

We have studied systematically the distribution of receptors for substance P in the airway smooth muscle of the rabbit using both functional studies and light-microscopic autoradiography. Four areas of the respiratory tract were examined: the midtrachea (T1) and proximal, middle and distal portions of the right main bronchus (B1, B2 and B3, respectively). The magnitude of the contractile response to substance P in preparations from six to eight animals was location-dependent, increasing significantly from proximal to distal areas. Maximal tension expressed as a function of tissue weight +/- S.E.M. was 24.8 +/- 3 for T1, 39 +/- 10 for B1, 108 +/- 31 for B2 and 160 +/- 42 for B3. The potency of substance P in B2 and B3 was significantly greater (EC50 = 4.8 x 10(-7) M; 2.8 x 10(-7) M, respectively) than that in T1 (2.5 x 10(-6) M). After inhibition of endogenous enkephalinase by phosphoramidon there was an increase in sensitivity to substance P in both T1 (EC50 = 2.3 x 10(-7) M, n = 5) and B3 (2.6 x 10(-9) M, n = 5). There was remarkable agreement in the results obtained with autoradiography. No binding sites (0) were visualized to Bolton Hunter substance P in T1. Sparse but specific binding (+) was seen in B1, whereas it was marked ( ) in B2 and very dense ( ++) in B3. Thus, our results have shown that receptors for substance P are more numerous in the distal than proximal airways of the rabbit. This may indicate a physiological role for substance P in the regulation of airway smooth muscle tone in the distal airways.

Origin and colocalization of CGRP- and SP-reactive nerves in cat airway epithelium

A combination of neuroanatomic techniques was used to examine the origin and neuropeptide content of nerve fibers in the airway epithelium of adult cats. By the use of immunocytochemical methods, the peptides substance P (SP) and calcitonin gene-related peptide (CGRP) were colocalized in airway epithelial nerve fibers. Two days after wheat germ agglutinin (WGA) was injected into the nodose ganglion, fibers containing WGA immunoreactivity (IR) were detected in the airway epithelium. SP-like immunoreactivity (LI) and CGRP-LI were demonstrated separately in the WGA-IR fibers, establishing their origin from nerve cell bodies of nodose ganglion. Vagal transection inferior to the nodose ganglion reduced the number of SP- and CGRP-IR fibers by greater than 90% in ipsilateral airways. In contralateral airways, SP-IR fibers were substantially reduced, whereas the effect on CGRP-IR fibers was not statistically significant. Vagotomy superior to the nodose ganglion did not alter the density of peptide-IR fibers. The results prove that SP- and CGRP-IR nerve fibers of cat airway epithelium originate from nerve cell bodies in the nodose ganglion and that SP- and CGRP-like peptides may be stored together in some nerve fibers of the airway epithelium.

Chemical structure of phospholipids in the lungs and airways of sheep

Experiments on phospholipids from the alveolar lining, bronchi and trachea were conducted to support the concept that different lipid complexes are synthesized and released at different sites in the pulmonary system. Tracheal, bronchial and bronchioalveolar lavages were obtained from healthy adult Merino breed ewes following euthanasia and a structural analysis of the phospholipid fraction made by fast atom bombardment mass spectrometry. The major components in tracheal lavage were: 72% phosphatidylcholines (PC), 8% phosphatidylethanolamines (PE) and 11% phosphatidylglycerols (PG) compared to 78% PC, 13% PE and 3% PG in bronchioalveolar lavage. The fatty acid profile of tracheal lavage showed that 73% of the PG and 3% of the PC contained an arachidonic acid side chain. These species were not found in bronchioalveolar lavage. The nearly four-fold increase in PG, and the different molecular species identified in tracheal compared to bronchioalveolar lavage, suggest local synthesis and release of phospholipids by tracheal epithelial cells. The distribution of these phospholipids may have functional properties desirable for normal mucociliary function and are consistent with published measurements from cultured tracheal epithelia cells.

Immunohistochemical study of lung adenocarcinoma using monoclonal antibody for 60-kilodalton antigen in type II pneumocytes and nonciliated bronchiolar epithelial cells. Comparison with two antisurfactant apoprotein antibodies

Monoclonal antibody KP16D3 was produced by immunizing mice with monkey bronchoalveolar lavage. KP16D3 revealed the immunohistochemical reactivity in the cytoplasm of some nonciliated bronchiolar epithelial cells and type II pneumocytes and thereby recognized specifically a protein with an apparent molecular weight of 60 kD with the use of Western blotting and immunoaffinity column chromatography followed by SDS-PAGE. Examination of 76 primary and 4 metastatic lung carcinomas in primary lung carcinoma KP16D3 showed immunohistochemical positivity only to mucin-nonproducing papillary adenocarcinoma (27/28) and bronchioloalveolar carcinoma (2/2), except for one case of large cell carcinoma. All other primary lung carcinomas such as squamous cell carcinoma, acinar adenocarcinoma, and small cell carcinoma had negative results. From these findings, KP16D3 seems to be an effective immunohistochemical marker of mucin-nonproducing papillary adenocarcinoma and bronchioloalveolar carcinoma of the lung and it appears to be useful to investigate both the histogenesis and functional expression of primary lung adenocarcinoma.

The distribution of heavy-chain isoforms of myosin in airways smooth muscle from adult and neonate humans

Changes in the expression of heavy chains of myosin during development determine the functional characteristics of striated muscles. The distribution of heavy-chain isoforms of smooth-muscle myosin was determined in the airways of adult and infant humans to see whether it might underlie the hyperreactivity of human airways. The protein bands corresponding to myosin were separated using SDS/polyacrylamide-gel electrophoresis (4% gels) and identified by immunoblotting using both monoclonal and polyclonal antibodies against smooth-muscle myosin and non-muscle myosin. The relative proportion of each heavy chain stained by Coomassie Blue was measured by densitometric scanning. Three major bands corresponding to myosin heavy-chain isoforms were found; the two slower migrating bands (MHC1 and MHC2) were smooth-muscle myosin, and the third band was non-muscle myosin. The MHC1/MHC2 ratio was 0.69:1 in adult bronchus, and in infant bronchus and trachea. This contrasted with the airway smooth muscle in pigs, which was run concurrently, where the smooth-muscle heavy-chain ratio changed with development [Mohammad & Sparrow (1988) FEBS Lett. 228, 109-112]. The non-muscle myosin heavy chain comprised 63% of the smooth-muscle myosin. In both adult and infant lungs an additional putative myosin heavy chain which migrated slightly more rapidly than non-muscle myosin heavy chain was identified using the monoclonal smooth-muscle myosin antibody BF 48. This was unique to the human species.

Use of an antiserum against deglycosylated human mucins for cellular localization of their peptide precursors: antigenic similarities between bronchial and intestinal mucins

Highly glycosylated regions of mucins, or glycopeptides, were obtained by proteolysis of human bronchial mucins. They were deglycosylated by treatment with a trifluoromethane sulfonic acid/anisole mixture and subsequent solvolysis with anhydrous liquid hydrogen fluoride. The resulting peptides were then used to raise an immune serum in rabbit. This immune serum was used to localize the peptide precursors of human respiratory mucins within bronchial cells, using an immunohistochemical method. Two main patterns of labeling were observed in the goblet cells: the entire cytoplasm of some goblet cells was immunoreactive, whereas in other cells the labeling was concentrated around the nucleus. In the respiratory mucous glands, the labeling was localized around or below the nucleus. The serous cells were not stained. Similar labeling was observed in human colon goblet cells. This immune serum seems to be specific for mucin-secreting cells and has a strong affinity for the perinuclear region of these cells.

Antileukoprotease-containing bronchiolar cells. Relationship with morphologic disease of small airways and parenchyma

Twenty-seven surgically removed lungs and lobes were studied to assess the relation between the abundance of bronchiolar epithelial cells containing antileukoprotease (ALP) (ALP-pos/mm) and the degree of small airways disease (SADscore) and emphysema (destructive index = DI, and number of normal alveolar attachments on membranous bronchioles = normal AA/min). Between subjects, ALPpos/mm correlated with SADscore in membranous bronchioles (rs = 0.75; p less than 0.001) and with normal AA/mm (rs = -0.38; p = 0.05). Evaluation within each subject revealed significant correlations of ALPpos/mm with SADscore in membranous as well as in respiratory bronchioles (p less than 0.001), and also with normal AA/mm (p = 0.005). In membranous and in respiratory bronchioles, ALPpos/mm correlated significantly with the ALP concentration in homogenized tissue, as measured by ELISA (rs = 0.55 and 0.57, respectively; p less than 0.01). It is concluded that disease in small airways and destruction of their alveolar attachments are associated with a rise of the number of ALP-containing epithelial cells. We hypothesize that this cellular increase is part of the general defense against inflammatory and destructive processes in distal human airways, leading to higher levels of proteinase inhibitor in order to minimize tissue damage.

Covalent DNA damage in tissues of cigarette smokers as determined by 32P-postlabeling assay

Covalent DNA addition products (adducts) formed by the reaction of chemical carcinogens or their metabolites with DNA are critically involved in the initiation of chemical carcinogenesis and may serve as molecular markers and dosimeters for environmental carcinogen exposures. Using a highly sensitive 32P-postlabeling assay for DNA adduct analysis, we studied DNA damage elicited by cigarette smoke in tissues of smokers. A multitude of characteristic smoking-induced, presumably aromatic DNA adducts were found to occur in a dose- and time-dependent manner in the lung, bronchus, and larynx of smokers with cancer of these organs and to decline only slowly after cessation of smoking. Low levels of adducts appeared to persist for up to 14 years in the lungs of exsmokers with high previous exposures. These results corroborate data of epidemiological studies showing that the lung cancer risk and mortality of smokers increase with the intensity and duration of smoking and decline only slowly after cessation of smoking. Tissue distribution studies in autopsy samples revealed the presence of smoking-associated DNA lesions also in the kidney, bladder, esophagus, heart, ascending aorta, and liver. The most extensive DNA damage was found in lung and heart, i.e., 1 aromatic adduct in about 10(7) DNA nucleotides. Our results suggest that cigarette smoking-induced DNA adduct formation is causally related to cancer in the target organs.

Distribution of vitamin B12 R-binder in lung tumors. Implications for cell differentiation

Expression of vitamin B12 R-binder, a specific binding protein for vitamin B12, was studied immunohistochemically in normal lung tissues and 107 lung tumors of various types. In normal tissues, vitamin B12 R-binder (R-binder) expression was restricted to the mucous cells of bronchial or bronchiolar epithelium and submucosal glands as well as to nonciliated bronchiolar (Clara) cells. Among lung carcinomas, 38% of squamous cell carcinomas, 42% of adenocarcinomas and 23% of large cell carcinomas showed positive staining for R-binder whereas small cell carcinomas did not. These findings offer the possibility that a majority of the histologic types of lung carcinoma have common histogenetical characteristics with mucous or Clara cells. Of the bronchial gland tumors, R-binder could be detected in a mucoepidermoid carcinoma but not in adenoid cystic carcinomas. Epithelial components in both pulmonary blastomas and hamartomas showed a reactivity for R-binder, suggesting that these tumors contained components composed of cells with bronchiolar cell differentiation. The immunohistochemical examination of lung tumors, using anti-R-binder antibody, may have some implications in the cell differentiation of lung tumors.

Effects of serum, transforming growth factor type beta, or 12-O-tetradecanoyl-phorbol-13-acetate on ionized cytosolic calcium concentration in normal and transformed human bronchial epithelial cells

Fluctuations in ionized cytosolic calcium ([Ca2+]i) are considered important signals for induction of growth or differentiation in mammalian cells. The resting concentrations of [Ca2+]i in normal and adenovirus 12-SV40 hybrid virus-transformed (BEAS-2B) human bronchial epithelial cells were 63 +/- 15 nM (SD) and 44 +/- 15 nM, respectively. Eight % calcium-free fetal bovine serum rapidly caused a significant increase in [Ca2+]i, while causing both cell types to undergo squamous differentiation. When treated with 8% calcium-free fetal bovine serum, a serum-sensitive subclone of BEAS-2B cells exhibited a higher elevation of [Ca2+]i than a serum-resistant (i.e., not stimulated to differentiate by serum) subclone. However, a serum component involved in the induction of squamous differentiation, transforming growth factor type beta, did not increase [Ca2+]i in either normal cells or BEAS-2B cells. 12-O-Tetradecanoyl-phorbol-13-acetate, an exogenous inducer of squamous differentiation and activator of protein kinase C, did not increase [Ca2+]i, but did attenuate serum-induced elevation of [Ca2+]i. These results suggest that while an increase in [Ca2+]i is associated with serum-induced squamous differentiation, a cytosolic ionized calcium signal is not required for the initiation of the squamous differentiation pathway induced by either transforming growth factor type beta or 12-O-tetradecanoylphorbol-13-acetate.

Protein components of human tracheobronchial mucin: partial characterization of a closely associated 65-kilodalton protein

A high-density mucin glycoprotein was isolated from human tracheobronchial secretions substantially free of contaminating protein, low-density glycoprotein, proteolytic enzymes, and lipid. A closely associated 65-kDa protein was discovered while investigating the effect of 2-mercaptoethanol treatment on the purified mucin glycoprotein. It has been established that the 65-kDa protein is neither alpha 1-antichymotrypsin nor human serum albumin, two proteins of similar molecular weight which are found in crude tracheobronchial secretions. This protein lacks cross-reactivity with antibodies directed against serum components and is presumably comparable to the 65-kDa protein similarly isolated from canine tracheal pouch secretions [Ringler et al. (1987) Biochemistry 26, 5322-5328]. Although both the presence of sulfhydryl groups and the ability to be reassociated with the mucin molecule have been established, it is not clear whether its association is due to direct disulfide bonding, hydrophobicity, or entrapment. It was found that 14C-methylated methemoglobin was an inappropriate substrate for measurement of proteolytic activity in mucin preparations due to inherent entrapment and clearance capabilities of mucin molecules.

Presence of the Dr receptor in normal human tissues and its possible role in the pathogenesis of ascending urinary tract infection

The Dr hemagglutinin of uropathogenic Escherichia coli recognizes the Dra blood group antigen, a component of the IFC or Cromer-related blood group complex. The present report used the Dr hemagglutinin to demonstrate location of the Dr receptor in selected human tissues and to evaluate the possible use of this lectin as a tissue marker recognizing sites sensitive for bacterial colonization. It was found that the Dr receptor was expressed in different parts of the digestive, urinary, genital, and respiratory tracts, and skin. Intense staining by Dr hemagglutinin was shown in colonic, bronchial, and endometrial glands, and skin eccrine sweat glands. Structures of the urinary tract showing strong fluorescence were renal tubular basement membrane, Bowmans' capsule, and transitional epithelium. The role of Dra antigen as receptor for adhesion for Dr-positive E. coli in ascending colonization of urinary tract and the possible importance of Dra in human pathology is discussed.

The sensitivity of detection of asbestos bodies in sputa and bronchial washings

While asbestos bodies (ABs) in sputum and/or bronchial washings are highly specific markers for significant asbestos exposure, comparison of the sensitivity between sputum cytology and bronchial washing cytology for the detection of ABs had not been documented. Review of the files of the Cytopathology Laboratory, Methodist Hospital, Houston, Texas, for the period 1973 to 1984 identified 11 patients with slides available for review who (1) had been examined by both sputum cytology and bronchial washing cytology and (2) had at least one specimen positive for ABs. Of the 11 evaluable cases, all had ABs in the bronchial washings but ony 6 had ABs in the sputum. In addition, iron stain (e.g., the Prussian blue stain) was found to be more sensitive than the Papanicolaou stain for the detection of ABs in these cases. These findings indicate that iron-stained bronchial washing specimens should be preferred for the cytologic detection of asbestos exposure.

Composition and surface properties of the bronchial lipids in adult patients with cystic fibrosis

Bronchial secretions from seven patients with cystic fibrosis (CF) were aspirated by fibreoptic bronchoscopy and analysed for lipid composition. The total lipid fraction was also used to measure dynamic surface tension. Pooled samples from 'normal' patients, healthy volunteers, patients with chronic bronchitis, and individual samples from two patients with bronchiectasis were used as controls. Increased bronchial inflammation and infection correlated with a decrease of the phospholipid fraction, and an increase of the cholesterol, diglyceride and triglyceride fractions. When individual phospholipids were analysed, patients with clinically severe CF showed a markedly decreased phosphatidylcholine fraction, whereas the phosphatidylinositol fraction was significantly higher in CF patients than in controls (p less than 0.05). Minimum surface tension was higher in CF patients compared to patients with chronic bronchitis (p less than 0.05). This might be related to earlier reported specific changes in the pattern of fatty acids of the CF bronchial phospholipids.

Effects of noradrenaline on the isolated human bronchus. Comparison with the isolated guinea pig trachea

The pharmacodynamic activity of noradrenaline was evaluated comparatively in vitro on isolated human bronchi and on guinea pig tracheal spirals. Noradrenaline exerted a contractile effect on both preparations under resting tone and in the presence of propranolol 10(-6) M; maximal noradrenaline-induced contraction was 15-20% of maximal acetylcholine (ACh)-induced contraction. Without propranolol, the contractile effect of noradrenaline was negligible when the preparations were under resting tone and absent when they were precontracted with ACh. In contrast, noradrenaline exerted a strongly relaxant effect on both human bronchi (-log ED50 5.24 +/- 0.17; N = 5) and guinea pig tracheae (-log ED50 6.15 +/- 0.29; N = 8). With maximal contraction induced by ACh 3.10(-3) M the -log ED50 of both preparations were shifted to the right by functional antagonism and became 4.72 +/- 0.17 and 5.31 +/- 0.11, respectively. The pKD values of noradrenaline, calculated according to Furchgott and Bursztyn (1967), were 4.79 +/- 0.04 in human bronchi (N = 5) and 4.77 +/- 0.16 in guinea-pig tracheae (N = 8). In the presence of cocaine plus phenoxybenzamine these values were not significantly modified in human bronchi and only slightly modified in guinea pig tracheae. It is concluded that noradrenaline induces a strong beta-adrenergic response and a negligible alpha-adrenergic response from both human bronchi and guinea pig tracheae in vitro.

The mechanism of tachykinin-induced bronchoconstriction in the rat

The mammalian tachykinins substance P (SP) and neurokinin A (NKA) are known to be present in sensory airway nerves of animals and humans. We studied the effect of mammalian and nonmammalian tachykinins on the conducting airways of anesthetized, mechanically ventilated Fisher 344 rats. Dose-dependent increases in lung resistance and decreases in dynamic compliance occurred after the intravenous administration of eledoisin (E), kassinin (K), NKA, and SP. E, K, and NKA were more potent bronchoconstrictors than was SP. Neurokinin B (NKB) caused a similar decrease in dynamic compliance, but had no effect on lung resistance. This order of potency suggests a predominance of NK-2 receptors in the rat airways. Both atropine and the 5-hydroxytryptamine antagonist methysergide largely reduced the bronchoconstriction induced by E and SP. Vagotomy did not change this reaction, whereas pretreatment with the ganglion blocker hexamethonium slightly enhanced the bronchoconstrictor action of E and SP. Sodium cromoglycate and nedocromil sodium, 2 drugs that can inhibit mediator release from inflammatory cells, significantly reduced the bronchoconstrictor action of NKA. Ketotifen, an antihistamine with mast-cell-stabilizing properties, significantly reduced the bronchoconstriction induced by E, whereas the H1-receptor antagonist clemastine had no effect. We conclude that tachykinins cause bronchoconstriction in rats largely by an indirect mechanism, involving both acetylcholine and 5-hydroxytryptamine. We suggest that tachykinins cause bronchoconstriction by stimulation of postganglionic vagal nerve endings and mast cells.

Tracheobronchial epithelium of the sheep: III. Carbohydrate histochemical and cytochemical characterization of secretory epithelial cells

We examined histochemically (light microscopy-LM) and cytochemically (electron microscopy-EM) the secretory epithelial cells in the tracheobronchial mucosa of sheep. Six morphologically distinct, granule-containing cells have been described, on the basis of their morphology and airway distribution: four mucous (M1-M4), serous (SC), and Clara (CC). Stereological and morphometric data indicated that M3, M4, SC, and CC were distinctly different from each other and from M1 and M2 cells. Mucous cells M1 and M2 differed in granule morphology. Samples of tracheas, sixth-generation bronchi, distal bronchi, and terminal bronchioles of 18 adult sheep were examined. At the LM level, methacrylate sections were reacted with an alcian blue (pH 2.5), periodic acid Schiff (PAS) sequence to differentiate neutral from acidic glycoconjugates (GC), and a high-iron diamine (HID), alcian blue sequence to differentiate sulfated from nonsulfated (sialylated) GC. At the EM level the periodic acid-thiocarbohydrazide localized hexose-rich, neutral GC. Dialyzed iron (DI) and high-iron diamine localized carboxylated and sulfated GC, respectively. Granules of all but Clara cells were PAS-positive. All mucous cells contained acidic groups, but only M1 and M4 cells had LM-detectable sulfated GC. At the ultrastructural level, minimal but discernible HID and LID reaction product was observed on granule profiles of M2, M3, and SC, indicating acidic and sulfated GC not detected at the LM level. Histochemically, the sheep tracheobronchial epithelium was more similar to that of humans than some other examined mammalian species.

Autoradiographic localization of leukotriene C4 and D4 binding sites in guinea-pig lung

Binding of [3H]leukotriene C4 and D4 to guinea-pig lung sections was characterised and binding sites were localized by autoradiography. Both leukotrienes bound to guinea-pig lung sections and membranes with high affinity and with similar characteristics to binding in a membrane preparation. Autoradiography revealed that the distribution of LTC4 and D4 binding sites was markedly different. Smooth muscle and epithelium of central and peripheral airways were densely labelled with [3H]LTC4; vascular smooth muscle and alveolar walls were also labelled. With [3H]LTD4, however, there was no detectable labelling of airways or vessels but substantial labelling of alveolar walls. This lends further support that LTC4 and LTD4 binding sites differ and may not be identical with functional receptors.

Autoradiographic visualization of muscarinic receptors in human bronchi

To visualize muscarinic receptors in human bronchi, the stripping film method was used which permits direct autoradiographic localization of tissue labeling. Cryostate sections of human bronchi were fixed in 0.5% glutaraldehyde in Krebs-Ringer buffer, pH 7.0 for 30 min at 0 degrees C, washed in Krebs-Ringer buffer for 20 min at 0 degrees C and incubated with (-)-[3H]Quinuclidinyl benzilate [(-)-[3H]QNB] for 90 min at 37 degrees C. Specific (-)-[3H]QNB binding to tissue sections was saturable (receptor density of 0.14 +/- 0.03 fmol/tissue section) and of high affinity (Kd of 40 +/- 9 pM). For autoradiography, labeled tissue sections were covered with stripping film and exposed for 5 months. Muscarinic receptors in human bronchi were located predominantly in submucosal glands and parasympathetic ganglia. There was less labeling in smooth muscle cells and nerve bundles. Epithelium and blood vessels located within the bronchial wall were devoid of specific labeling.

Serum, sputum and bronchial concentrations of erythromycin in chronic bronchitis after single and multiple treatments with either propionate-N-acetylcysteinate or stearate erythromycin

Serum and bronchial concentrations of erythromycin were determined in 30 chronic bronchitic patients during an exacerbation phase of bacterial infections. The levels were measured after single and multiple oral treatments with erythromycin-propionate-N-acetylcysteinate (EPAC) or erythromycin stearate (ES) in a double-blind design. EPAC showed higher and longer-lasting erythromycin levels in serum, sputum and pure bronchial mucus than ES. It is believed that EPAC is better absorbed because of its greater stability in the gastrointestinal juices. Higher concentrations in bronchial secretions not always depend on the blood levels. It seems to be possible that the N-acetylcysteine moiety in the molecule of EPAC drug can facilitate antibiotic penetration because of its mucolytic activity. The clinical response (disappearance of fever, clearance of bacterial pathogens from sputum, reduction of quantity and viscosity of sputum) also occurred faster in the EPAC than in the ES group.

The heavy-chain stoichiometry of smooth muscle myosin is a characteristic of smooth muscle tissues

The stoichiometry of the two heavy chains of myosin in smooth muscle was determined by electrophoresing extracts of native myosin and of dissociated myosin on sodium dodecyl sulfate (SDS) 4%-polyacrylamide gels. The slower migrating heavy chain was 3.6 times more abundant in toad stomach, 2.3 in rabbit myometrium, 2.0 in rat femoral artery, 1.3 in guinea pig ileum, 0.93 in pig trachea and 0.69 in human bronchus, than the more rapidly migrating chain. Both heavy chains were identified as smooth muscle myosin by immunoblotting using antibodies to smooth muscle and non-muscle myosin. The unequal proportion of heavy chains suggested the possibility of native isoforms of myosin comprised of heavy-chain homodimers. To test this, native myosin extracts wer electrophoresed on non-dissociating (pyrophosphate) gels. When each band was individually analysed on SDS-polyacrylamide gel the slowest was found to be filamin and the other bands were myosin in which the relative proportion of the heavy chains was unchanged from that found in the original tissue extracts. Since this is incompatible with either a heterodimeric or a homodimeric arrangement it suggests that pyrophosphate gel electrophoresis is incapable of separating putative isoforms of native myosin.

Biotin stores in rodent lungs: localization to Clara and type II alveolar cells

Biotin is a cofactor for carboxylases used in fatty acid synthesis, gluconeogenesis, and energy production by the citric acid cycle. Although lung has low levels of this vitamin overall, high concentrations were demonstrated histochemically in Clara cells of mouse, rat, hamster, and guinea pig using avidin conjugated to peroxidase. Lesser concentrations were found in type II cells of mouse, rat, and hamster but not guinea pig. By electron microscopy, biotin stores in mouse Clara cells were localized to mitochondria, while those in type II cells were present in both mitochondria and the cytoplasmic matrix. Biotin stores in type II cells are probably used mainly in fatty acid synthesis but also in gluconeogenesis and energy production. The reason for particularly high concentrations in the mitochondria of Clara cells is unknown.

Relationship between leukotriene C4 and an uteroglobin-like protein in nasal and tracheobronchial mucosa of children. Implication in acute respiratory illnesses

Secretions from the nose and nasopharynx (NPS) are more readily accessible than tracheobronchial secretions (TBS) for clinical investigations, but it is unclear whether changes in mediator release in the nasopharynx reflect similar changes in the tracheobronchial tree. In order to clarify this question, NPS and TBS were taken from 20 children with tracheotomy and tested for the presence of leukotriene C4 (LTC4) and uteroglobin-like protein (UTG-LP). LTC4 and UTG-LP were measured both when the children were healthy and when they had clinical evidence of an acute respiratory tract illness. The mean concentration of LTC4 in NPS and TBS increased during illness although the mean concentration in NPS was significantly higher than in TBS during respiratory illness. In healthy children UTG-LP was detected only in TBS. During acute respiratory illness the concentration of UTG-LP in TBS decreased but remained significantly higher than in NPS. Data presented in this study indicate that changes in the LTC4 concentration in NPS appear to reflect changes in LTC4 concentration in TBS although the levels of LTC4 in NPS were significantly higher than in TBS. An inverse correlation between the concentrations of LTC4 and UTG-LP in NPS and TBS was demonstrated.

Co-localization of vasoactive intestinal peptide- and substance P-containing nerves in cat bronchi

The occurrence of vasoactive intestinal peptide (VIP) and substance P in nerve fibers within the lung is well established, and both VIP- and substance P-containing nerve fibers are known to supply pulmonary vascular and bronchial smooth muscle and submucosal glands. In the present study, we have investigated the co-localization of these two peptides in cat lung. The co-localization procedure follows a standard immunocytochemical protocol except that the primary and labeled secondary antisera each contain a combination of two antisera allowing the simultaneous detection of two antigens in a single tissue section. Using fluorescence microscopy, VIP- and substance P-containing nerve fibers were co-localized in bronchial smooth muscle, in the walls of pulmonary and bronchial arteries, and around submucosal glands. VIP and substance P were also co-localized in nerve cell bodies that comprised the intrinsic airway ganglia. Substance P-containing nerve fibers were observed within the bronchial epithelium, but VIP was not present at this location. The co-localization of VIP and substance P in the same nerve fibers suggests that airway and pulmonary vascular function may be partially regulated by the simultaneous or sequential release of VIP and substance P from the same nerve fibers. The results also suggest that, in addition to extrinsic nerve fibers that contain substance P, the airways of cats are supplied by substance P-containing nerve fibers that originate from intrinsic nerve cell bodies.

Peptides of human bronchial mucus glycoproteins. Size determination by electron microscopy and by biosynthetic experiments

Secreted human bronchial mucins, directly collected from macroscopically healthy bronchial mucosa, were prepared in the presence of six proteinase inhibitors, and analysed by electron microscopy. These mucins were similar in length distribution to molecules prepared from sputum [Slayter, Lamblin, Le Treut, Galabert, Houdret, Degand & Roussel (1984) Eur. J. Biochem. 142, 209-218], although they were a little longer, their lengths ranging up to about 1,650 nm. This length corresponds to an extended mucin peptide of about 450 kDa. In order to compare these peptide lengths with the molecular size of biosynthetic precursors, an antiserum raised against trifluoromethanesulphonic acid-treated highly glycosylated regions of human bronchial mucins was used to isolate mucin precursors synthesized in explants of human bronchial mucosa during pulse-labelling with [3H]threonine or [3H]glucosamine. A main precursor labelled with [3H]threonine and with an apparent molecular mass of about 400 kDa was detected by fluorography following SDS/polyacrylamide-gel electrophoresis. This band was observed as early as 20 min; it was more intense after a 40 min chase and had disappeared after a chase period of 280 min in unlabelled medium, presumably owing to glycosylation. Much fainter bands at about 200 kDa and between 200 and 400 kDa, also labelled with [3H]threonine, were observed mainly after a 40 min chase and had disappeared after a 280 min chase. None of these bands was labelled with [3H]glucosamine, nor did they disappear after multiple treatments with immobilized lectins. After a 280 min chase, [3H]threonine-labelled material appeared in the stacking gel, which also contained [3H]glucosamine label. The results indicate that the 200-400 kDa species are mucin precursors, whose size is comparable with that obtained by electron microscopy for respiratory mucins collected directly from the macroscopically healthy bronchial mucosa.

Immunohistochemical localization of a low molecular weight surfactant-associated protein in human lung

We used an antiserum to a hydrophobic 6 KD surfactant-associated protein to localize this protein in human lung tissue. This antiserum does not crossreact with the 35 KD surfactant-associated protein. By light microscopy using the indirect immunoperoxidase technique, the protein appears to be localized within Type II alveolar epithelial cells. Staining is also detectable in alveolar macrophages and occasionally within the lumina of alveoli and bronchioles. No staining was detected within the alveolar septa or in association with blood vessels. An identical distribution is seen for the 35 KD surfactant-associated protein using an antiserum specific for that protein.

The pathology of the early and late stages of primary pulmonary hypertension

During the course of a case of primary pulmonary hypertension occurring in a 24 year old man lung tissue became available at heart-lung transplantation in 1986 and from a lung biopsy carried out in 1981. In 1986 the sections showed classic plexogenic pulmonary arteriopathy. In 1981 they revealed migration of myofibroblasts into the intima and lumen of pulmonary arteries and arterioles, the identification of the cells being confirmed by electron microscopy. During the five years that the pulmonary vascular pathology progressed to the formation of plexiform lesions there was an increase in the number of bronchiolar endocrine cells that were immunoreactive to bombesin and calcitonin. This study demonstrates that the classic pathogenesis of primary plexogenic pulmonary arteriopathy originates years earlier as a migration of cells of muscular pedigree from the media into the intima of the pulmonary arteries and arterioles.

Characteristics and distribution of specific binding sites for leukotriene C4 in human bronchi

The binding of [3H]leukotriene (LT) C4 to membranes from human bronchi has been characterized. The specific binding, measured at 4 degrees C, was very rapid, equilibrium being attained within 1 to 5 min. The binding was also rapidly reversible and saturable (maximum binding = 187 pmol/mg of protein). LTC4, LTD4, LTE4 and the LT antagonist FPL 55712 competed with [3H]LTC4 for its binding sites, with the following IC50 values: 0.12; 2.3; 30; and 20 microM. Therefore, the binding sites displayed a higher affinity for LTC4 than for the other sulfidopeptide LTs. Computer-assisted analysis of either the saturation or the competition curves for LTC4 indicated the existence of two classes of binding sites with different affinities (Kd1 and Kd2 = 70 nM and 0.58 microM, respectively), in agreement with the curved semilog plot of the dissociation time course. CaCl2 or MgCl2 increased and GTP or 5'-guanylylimidodiphosphate did not decrease the specific binding. In addition, the distribution of the binding sites for [3H]LTC4 along the human respiratory tree was investigated. At a fixed (10 nM) [3H]LTC4 concentration, membranes obtained from bronchi removed at different levels of the airway tree did not bind LTC4 in a significantly different amount. This is compatible with the finding that LTC4 receptors should be present on bronchi of various caliber, as both small and large airways respond to LTs.

Dry mass, DNA and non-histone protein determinations in lung cancer cells

Cell nuclei from two biopsies of bronchial mucosa, seven squamous-cell carcinomas and six small-cell carcinomas of the lung were investigated. DNA and non-histone protein (NHP) content were simultaneously determined in Feulgen-Naphthol Yellow S-stained smears by means of multiple plug cytophotometry. In addition, the nuclear dry mass of cells originating from the same populations was measured by interference microscopy. DNA histograms of carcinomas were characterized by DNA stemlines being situated in the diploid range in four out of six small-cell carcinomas and in the hyperdiploid to hypertetraploid range in six out of seven squamous-cell carcinomas. Polyploid values (up to 8 c) were seldom found in small-cell carcinomas whereas squamous-cell carcinomas showed a broader dispersion approaching the 16 c level. The similarity of the NHP distributions with the DNA histograms was more marked in small-cell carcinomas than in the squamous-cell carcinomas. In comparison with the NHP distributions of normal bronchial epithelial cells, those of carcinomas were shifted to higher values. The increased NHP content was found to be a more prominent sign of malignancy in small-cell carcinomas than the DNA mass. The increase in nuclear dry mass in carcinomas was mainly caused by the accumulation of NHP in tumour cell nuclei.

Cellular and protein changes in bronchial lavage fluid after late asthmatic reaction in patients with red cedar asthma

To investigate the sequence of cellular and protein changes after a late asthmatic reaction (LAR), bronchial lavage was carried out in 44 patients with red cedar asthma at different time intervals after bronchial challenge with plicatic acid. The results were compared to five patients with red cedar asthma who became asymptomatic after removal from exposure to red cedar for more than 2 months and 31 healthy subjects without asthma. The LAR was found to be associated with an increase in eosinophils in the lavage fluid, an increase in sloughing of bronchial epithelial cells, and an increase in degenerated cells consisting mainly of degenerated epithelial cells and alveolar macrophages. There was an increase in vascular permeability as reflected by an increase in albumin in the lavage fluid. Although there was a slight but significant increase in neutrophils 48 hours after bronchial challenge, neutrophil infiltration was not a prominent feature earlier. The potential role of loss of epithelial cells to account for an increase in nonspecific bronchial hyperresponsiveness after an LAR was discussed.

Hyaluronic acid in bronchoalveolar lavage in rats exposed to quartz

Hyaluronic acid, a connective tissue component, in bronchoalveolar lavage fluid (BAL) is correlated with decreased lung volumes in sarcoidosis. To investigate whether hyaluronic acid could be a marker of fibrosis in another interstitial lung disease, silicosis, the level of the substance in BAL fluid from rats exposed to crystalline silica (n = 3), amorphous silica (n = 3), and in one sham injected rat was measured. There was an increase in the total number of alveolar cells recovered in the rats exposed to crystalline silica and also a pronounced increase in the proportions of neutrophils and lymphocytes. In addition, the concentration of hyaluronic acid was high in this group of rats, and electron microscopic investigation of the lungs showed fibrosis. Thus hyaluronate in BAL fluid in rats exposed to crystalline silica seems to be a possible marker of fibrotic changes.

Epidermal growth factor receptors in non-small cell lung cancer

The epidermal growth factor receptor is homologous to the oncogene erb-beta and is the receptor for a class of tumour growth factors (TGF-alpha). The clinical correlations with its expression were studied in 77 non-small cell lung cancers (NSCLC). They were stained for epidermal growth factor receptor (EGFr) by means of an indirect immunoperoxidase technique using a monoclonal antibody against the receptor. Normal lung tissue and normal bronchus were stained for comparison. Cancer tissue showed significantly increased staining compared to normal lung (P less than 0.05). Staining for EGFr in 40 squamous carcinomas was significantly stronger than in 37 specimens of other types of NSCLC (P less than 0.05), and staining in stage three NSCLC was stronger than in stage 1 and 2 (P less than 0.05). These results suggest that the presence of a high intensity of staining for EGF receptor is associated with spread of human non-small cell lung cancer and this receptor may be a suitable target for therapy.

Occurrence and effects of multiple tachykinins; substance P, neurokinin A and neuropeptide K in human lower airways

In the present work we have studied the occurrence of different tachykinins (substance P (SP), neurokinin A (NKA) and neuropeptide K (NPK)) in human distal bronchi and pulmonary arteries by means of radioimmunoassay (RIA) and high performance liquid chromatography (HPLC). We have also compared the biological effects of different tachykinins on isolated human bronchi and pulmonary arteries in vitro. The concentration of immunoreactive SP using antiserum SP2 in the pulmonary arteries was higher (1.34 +/- 0.15 pmol/g) than in the bronchi (0.56 +/- 0.05 pmol/g). The contents of other tachykinins than SP measured using antiserum K12 was on the other hand considerably higher in the bronchi (0.33 +/- 0.14 pmol/g) than in pulmonary arteries (0.13 +/- 0.02 pmol/g). Immunoreactive materials corresponding to SP, NKA and NPK were identified in bronchial extracts by RIA combined with HPLC, which also indicated the presence of an eledoisin (ELE)-like component. In vitro studies showed that NKA was the most potent of the tachykinins as a bronchoconstrictor agent, being several hundred-fold more active than SP, acetylcholine and histamine. NPK had an intermediate potency. The bronchoconstrictor effect of NKA was unaffected by atropine, mepyramine and cimetidine. The tachykinins SP and NKA had on the other hand, a rather equal potency in inducing relaxation of serotonin precontracted pulmonary arteries. In conclusion, multiple tachykinins are present in lower airways of man. These peptides exert different biological activities whereby NKA is a very active bronchoconstrictor agent compared to SP while both NKA and SP have rather similar relaxatory activities of vascular smooth muscle.

Purification and characterization of human bronchial proteinase inhibitor

We describe a purification procedure for the human bronchial proteinase inhibitor which involves trichloroacetic acid precipitation of sputum followed by ion-exchange and gel filtration chromatography. The inhibitor shows a major band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but exhibits microheterogeneity on high-resolution chromatography. It has a molecular mass of 15.5-16 kDa as determined by electrophoresis and gel filtration and is 90% active against leukocyte elastase. The amino acid sequence of the N-terminal portion of the inhibitor was determined and was found to be identical (through 29 amino acids) to that recently reported for the human seminal plasma proteinase inhibitor I (Seemuller et al. (1986) FEBS Lett. 199, 43-48).

A muscarinic receptor with high affinity for pirenzepine mediates vagally induced bronchoconstriction

The nature of the putative muscarinic receptor subtypes involved in vagally mediated bronchoconstriction was examined in the rabbit model utilizing the classical muscarinic antagonist atropine and the selective antagonist pirenzepine. In vivo electrical stimulation of the cervical vagus nerves in anesthetized rabbits resulted in a reproducible increase in pulmonary resistance indicative of bronchoconstriction and a marked negative chronotropic effect on the heart. Both atropine and pirenzepine produced dose-related inhibition of these two vagal effects. Fifty percent inhibition of the vagally induced increase in pulmonary resistance was achieved with an infusion of pirenzepine that was only 8-fold greater than the equi-effective dose of atropine. In contrast, the dose of pirenzepine required to inhibit the vagally induced decrease in heart rate by 50% was 100-fold greater than the atropine dose. Thus, pirenzepine is markedly more potent in inhibiting vagally mediated bronchoconstriction than bradycardia. In vitro inhibition of methacholine-induced contraction of bronchial rings with atropine and pirenzepine yielded pA2 values of 8.86 and 6.88 respectively (95-fold potency ratio), demonstrating that the muscarinic receptors on airway smooth muscle cells that mediate contraction are not of the pirenzepine-sensitive subtype.

Chromogranin in bronchopulmonary neuroendocrine cells. Immunocytochemical detection in human, monkey, and pig respiratory mucosa

Immunoreactive chromogranin A was demonstrated by immunocytochemistry in the cytoplasm of neuroendocrine cells (NEC) and neuroepithelial bodies (NEB) in human, monkey, and pig respiratory mucosa. Three different antisera (one monoclonal and one polyclonal to human chromogranin A, and one polyclonal to bovine chromogranin A) were applied in this study. Chromogranin immunopositivity varied in extent and intensity according to the antiserum applied and the tissue investigated. The monoclonal antibody revealed the strongest immunoreaction. Good correlation between chromogranin immunoreactivity and Grimelius silver staining was observed by comparing adjacent sections, although more cells seemed to reveal chromogranin immunoreactivity than argyrophylia. Chromogranin appears to be a useful histological marker for APUD cells in the respiratory mucosa of several species.

Chemical analysis of the bronchoalveolar washing fluid in the diagnosis of liquid paraffin pneumonia

Lipid analyses of the bronchoalveolar washing fluid of three patients affected with chronic unidentified pneumonia showed the presence of a major hydrophobic compound identified as paraffin oil by thin layer chromatography, infrared spectroscopy and gas liquid chromatography (by comparison with various paraffin preparations as standards). Moreover the phospholipid and neutral lipid composition was determined. In conclusion, the usefulness of bronchoalveolar lavage and its biochemical analysis is discussed as a non-invasive method of diagnosis and therapeutic approach to liquid paraffin pneumonia (in the cases herein described, between 100 and 500 mg of paraffin oil were extracted from 100 ml of bronchoalveolar washing fluid.

Penetration of ceftazidime into the rabbit respiratory tract

A procedure is described for the direct collection of bronchial or tracheal fluid samples on to paper discs. Using the procedure, the pharmacokinetics of ceftazidime in rabbit bronchial and tracheal fluids were compared with those in the respective wall tissue samples and in lung tissue. Concentrations appearing in lung tissue were approximately half those seen in bronchial or tracheal fluid or bronchial and tracheal wall tissue. Concentrations in these latter compartments were, in turn, four- to six-fold lower at all times than simultaneously-measured serum levels. The shape of the concentration/time curves were similar for all compartments sampled. The half life values were 63 to 64 min for respiratory tract concentrations and 59 min for serum levels. Percentage penetration from serum into the various compartments was 20.8% for bronchial fluid, 19.9% for tracheal fluid, 22.4% for bronchial wall, 20.0% for tracheal wall and 11.3% for lung tissue.