Experimental measurements and empirical modelling of the regional deposition of inhaled particles in humans

Regional deposition of inhaled particles was studied experimentally in a hollow cast of the human larynx-tracheobronchial tree extending through the first six branching levels, and in twenty-six non-smoker human volunteers in vivo. Results of the hollow cast study indicated a linear dependence of particle deposition efficiency on the Stokes number for aerosols with aerodynamic diameters greater than 2 micrometers. Alveolar and total respiratory tract in vitro deposition in healthy non-smokers was minimal for particles of approximately 0.4 micrometers, and alveolar deposition for mouthpieces inhalations peaked for particles of approximately 3 micrometers. A new anatomic parameter, the bronchial deposition size (BDS), is introduced to permit the classification of various individuals and populations according to their tracheobronchial deposition efficiencies. The average BDS's were 1.20 cm for 26 healthy non-smokers, 1.02 cm for 46 cigarette smokers, 0.90 cm for 19 clinical patients being treated for obstructive lung disease and 0.60 cm for six severely disabled patients.     

Lymphoproliferative responses to antigens mediated by human pulmonary alveolar macrophages

We evaluated the ability of human pulmonary alveolar macrophages (PAMs) to mediate (3H)-thymidine incorporation by blood lymphocytes severely depleted of monocytes when stimulated with soluble microbial and allogeneic lymphocyte antigens. Low (less than 2%) concentrations of PAM's from nonsmokers or blood monocytes did not support optimal responses. Over all, at greater than or equal to 10% concentrations, PAM's from nonsmokers supported higher responses than monocytes. At less than or equal to 10% concentrations, PAM's from heavy cigarette smokers mediated significantly less incorporation than did similar concentrations of PAM's from nonsmokers (p less than 0.05). The findings indicate that PAM's from healthy nonsmokers are functionally competent macrophages in terms of mediating lymphoproliferation in cultures stimulated with antigens. This classical macrophage function is impaired with cigarette smoking.     

Alveolar macrophage release of tumor necrosis factor-alpha in chronic alcoholics without liver disease

Alcohol is an immunosuppressive drug, and chronic abuse has been associated with increased susceptibility to a variety of infections, including bacterial pneumonia and tuberculosis. Alveolar macrophages are the resident phagocytes of the lung and play a central role in lung host defenses against infection ranging from direct antibacterial activity to the release of proinflammatory cytokines such as tumor necrosis factor-alpha (TNFalpha). TNFalpha, in particular, plays a key role in the development of the early inflammatory response. In this study, we investigated the effects of chronic alcohol consumption on alveolar macrophage release of TNFalpha in vitro. We prospectively studied lipopolysaccharide (LPS)-stimulated release of TNFalpha from alveolar macrophages obtained from bronchoalveolar lavage fluid (BALF) in 22 alcoholic (18 smokers, 4 nonsmokers) and 7 nondrinking healthy volunteers (3 smokers, 4 nonsmokers). The total number of cells recovered by bronchoalveolar lavage (BAL) and their differential distribution were not significantly different in alcoholics versus controls (43 +/- 8 x 10(6) and 39 +/- 13 x 10(6), respectively). However, the total number of cells recovered from BALF was significantly higher in smokers (51 +/- 8 x 10(6)) than in nonsmokers (19 +/- 5 x 10(6)). Spontaneous (basal) release of TNFalpha by alveolar macrophages was the same in alcoholics and controls. In contrast, LPS-stimulated release of TNFalpha was significantly suppressed in alcoholics compared with that of controls (1343 +/- 271 vs. 3806 +/- 926 U TNF/ml/10(6) cells, respectively, p < 0.015). When controlled for smoking, LPS-stimulated TNFalpha production was suppressed in alcoholic nonsmokers (563 +/- 413 U TNF/ml/10(6)) compared with control nonsmokers (5113 +/- 1264 U TNF/ml/10(6)). LPS-stimulated TNFalpha production was also less in control smokers (2063 +/- 386 U TNF/ml/10(6) cells) than in control nonsmokers (5113 +/- 1264 U TNF/ml/10(6) cells). There was no difference in TNFalpha production between smoking alcoholics and smoking control subjects. We conclude that chronic alcohol consumption significantly suppresses LPS-stimulated alveolar macrophage production of TNFalpha. This effect is obscured if the subject also smokes. Because TNFalpha production is an important element in host defense, this may explain, in part, the susceptibility of chronic alcohol abusers to a variety of infections.     

Water translational motion at the bilayer interface: an NMR relaxation dispersion measurement

Nuclear magnetic relaxation rates for water protons in aqueous palmitoyloleoylphosphatidylcholine vesicle suspensions containing different nitroxide free radical spin labels are reported as a function of magnetic field strength corresponding to proton Larmor frequencies from 10 kHz to 30 MHz. Under these conditions the water proton relaxation rate is determined by the magnetic coupling between the water protons and the paramagnetic nitroxide fixed on the phospholipid. This coupling is made time-dependent by the relative translational motion of the water proton spins past the nitroxide radical. Using theories developed by Freed and others, we interpret the NMR relaxation data in terms of localized water translational motion and find that the translational diffusion constant for water within approximately 10 A of the phospholipid surface is 6 x 10(-10) m2 s(-1) at 298 K. Similar results are obtained for three different nitroxide labels positioned at different points on the lipid. The diffusion is a thermally activated process with an activation energy only slightly higher than that for bulk water.     

Relationship of Type A behavior pattern in smokers to carbon monoxide exposure and smoking topography.

Compared exposure to cigarette smoke in 42 graduate and undergraduate student smokers assessed for the Type A behavior pattern. After controlling for smoking rate and cigarette carbon monoxide yield, Type As' alveolar carbon monoxide (COa) levels were higher than Type Bs', and Jenkins Activity Survey scores were correlated with COa. To determine the source of this difference, smoking topography was measured in 10 Type As and 10 Type Bs. Results suggest that consummatory behaviors of Type As may help account for the Type A–coronary heart disease relationship for smokers. Due to increased smoke exposure, Type A smokers may also be at greater risk for cancer and lung disease. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A case of Sj?gren''s syndrome associated with advanced hemolytic anemia caused by worsening autoimmune cholangiopathy

AIMS: Recent research suggests that people who become smokers may be more sensitive to the positive effects of nicotine than those who do not take up smoking. DESIGN AND SETTING: The present study was designed to investigate this hypothesis by querying initial experiences with cigarette smoking in smokers, ex-smokers and never-smokers recruited from the local community. PARTICIPANTS: Subjects were 80 women (23 highly-dependent smokers (Fagerstrom Tolerance Questionnaire score > or = 7), 30 less-dependent smokers (FTQ < or = 6), 12 ex-smokers and 15 never-smokers). MEASUREMENTS: Subjects were asked to rate pleasurable sensations and displeasurable sensations on a scale of 1 = none to 4 = intense, and to indicate the presence or absence of pleasurable rush or buzz, relaxation, dizziness, nausea and cough; social context was also queried. Pleasurable rush or buzz, relaxation, dizziness, nausea and cough were related to ratings of pleasurable and unpleasant sensations to establish their affective valence. FINDINGS: Pleasurable sensations, pleasurable rush or buzz and relaxation (pleasant effects) were significantly more likely to occur in the smoker categories than in never-smokers. The ratio of pleasurable to unpleasant sensations, computed as an index of overall hedonic impact of initial exposure, also significantly favored the smoker categories. By contrast, unpleasant sensations, nausea and cough (unpleasant effects) did not differ significantly among groups. Dizziness, which did not definitely emerge as either pleasurable or unpleasant, was significantly more likely to be reported among the smoker groups than among never-smokers. CONCLUSIONS: People who become highly dependent cigarette smokers appear to have more pleasurable sensations at their initial exposure to tobacco; unpleasant reactions to the first cigarette do not seem to protect against subsequent smoking.     

In vitro induction of aryl hydrocarbon hydroxylase in human pulmonary alveolar macrophages by benzanthracene

Aryl hydrocarbon hydroxylase (AHH) was induced in human pulmonary alveolar macrophages (PAMs) cultured in the presence of benzanthracene. Time and dose--response curves were established for in vitro induction of this enzyme system in PAMs. In addition, a positive correlation was noted between the level of AHH activity in freshly lavaged PAMs and the in vitro inducibility of the enyzme in these cells from either nonsmokers or cigarette smokers. Measurements of the inducibility of AHH in cultured human PAMs provide an experimental system suitable for studying the mechanisms responsible for the initiation of pulmonary carcinogenesis.     

A partial agonist model used in the allosteric modulation of the NMDA receptor

In this study, we investigated the mechanism of alveolar macrophage activation by systemic administration of SSG, a soluble highly branched (1-->3)-beta-D-glucan obtained from a fungus Sclerotinia sclerotiorum IFO 9395. Multiple i.v. administration (10 mg/kg; once daily for 10 consecutive days) of SSG enhanced some functions of alveolar macrophages, such as lysosomal enzyme activity and nitric oxide secretion, on day 1 after the last administration, and it also elevated the concentrations of serum protein, interferon gamma and SSG in bronchoalveolar lavage fluid on the same day. On the in vitro assay system, stimulation by SSG alone (500 microg/ml) slightly augmented the lysosomal enzyme activity of alveolar macrophages, but it had no effect on nitric oxide production of cells. Stimulation by serum (1 or 10% mouse serum) or serum components, such as fibronectin (25 microg/ml) and albumin (500 microg/ml), alone strongly augmented only the lysosomal enzyme activity of alveolar macrophages, but it had no effect on nitric oxide secretion from cells, and no synergism or additive-like effect was observed between serum components and SSG. In contrast, stimulation by crude lymphokine (5%) or recombinant murine interferon gamma (100 U/ml) alone did not induce augmentation of lysosomal enzyme activity and nitric oxide production of alveolar macrophages in vitro, but when cells were incubated together with crude lymphokine or recombinant murine interferon gamma and SSG (500 microg/ml), a significant combined effect was observed on both functions of alveolar macrophages. In addition, pretreatment of crude lymphokine or recombinant murine interferon gamma enhanced the expression of beta-D-glucan specific binding sites on the alveolar macrophage surface in vitro though pretreatment by serum components had no effect. Based on these findings, the enhancement of alveolar macrophage functions by systemic administration of SSG appears to be mediated, at least in part, by both the simple effect of serum components including fibronectin and albumin leaked from pulmonary peripheral blood into the alveoli and the synergistic effect between lymphokines released from activated pulmonary T cells and SSG itself entering the alveoli after SSG injection via the priming effect of lymphokines which enhances the expression of beta-D-glucan specific binding sites on the alveolar macrophage surface.     

Smoke extract stimulates lung epithelial cells to release neutrophil and monocyte chemotactic activity

Inflammatory cells accumulate within the lungs of cigarette smokers. Current concepts suggest that these cells can induce protease-antiprotease and/or oxidant-antioxidant imbalance(s), which may damage the normal lung alveolar and interstitial structures. Because type II pneumocytes line the alveolar space, and because the inflammatory cells migrate and reside at the alveolus, we postulated that the type II pneumocytes might release chemotactic activity for neutrophils and monocytes in response to smoke extract. To test this hypothesis, A549 cells were cultured and the supernatant fluids were evaluated for the neutrophil and monocyte chemotactic activity (NCA and MCA) by a blind-well chamber technique. A549 cells released NCA and MCA in response to smoke extract in a dose- and time-dependent manner (P < 0.05). Checkerboard analysis showed that the activity was chemotactic. Partial characterization of NCA and MCA revealed that the activity was partly heat labile, trypsin sensitive, and ethyl acetate extractable. Lipoxygenase inhibitors and cycloheximide inhibited the release of NCA and MCA. Molecular sieve column chromatography showed multiple peaks for both NCA and MCA. NCA was inhibited by anti-human-interleukin (IL)-8 antibody, granulocyte colony-stimulating factor (G-CSF) antibody, or leukotriene (LT)B4 receptor antagonist. Monocyte chemoattractant protein (MCP)-1 antibody or LTB4 receptor antagonist inhibited MCA. Immunoreactive IL-8, G-CSF, MCP-1, and LTB4 significantly increased in the supernatant fluids in response to smoke extract. These data suggest that the type II pneumocytes may release NCA and MCA and modulate the inflammatory cell recruitment into the lung.     

Acute effects of inhaled urban particles and ozone: lung morphology, macrophage activity, and plasma endothelin-1

We studied acute responses of rat lungs to inhalation of urban particulate matter and ozone. Exposure to particles (40 mg/m3 for 4 hours; mass median aerodynamic diameter, 4 to 5 microm; Ottawa urban dust, EHC-93), followed by 20 hours in clean air, did not result in acute lung injury. Nevertheless, inhalation of particles resulted in decreased production of nitric oxide (nitrite) and elevated secretion of macrophage inflammatory protein-2 from lung lavage cells. Inhalation of ozone (0.8 parts per million for 4 hours) resulted in increased neutrophils and protein in lung lavage fluid. Ozone alone also decreased phagocytosis and nitric oxide production and stimulated endothelin-1 secretion by lung lavage cells but did not modify secretion of macrophage inflammatory protein-2. Co-exposure to particles potentiated the ozone-induced septal cellularity in the central acinus but without measurable exacerbation of the ozone-related alveolar neutrophilia and permeability to protein detected by lung lavage. The enhanced septal thickening was associated with elevated production of both macrophage inflammatory protein-2 and endothelin-1 by lung lavage cells. Interestingly, inhalation of urban particulate matter increased the plasma levels of endothelin-1, but this response was not influenced by the synergistic effects of ozone and particles on centriacinar septal tissue changes. This suggests an impact of the distally distributed particulate dose on capillary endothelial production or filtration of the vasoconstrictor. Overall, equivalent patterns of effects were observed after a single exposure or three consecutive daily exposures to the pollutants. The experimental data are consistent with epidemiological evidence for acute pulmonary effects of ozone and respirable particulate matter and suggest a possible mechanism whereby cardiovascular effects may be induced by particle exposure. In a broad sense, acute biological effects of respirable particulate matter from ambient air appear related to paracrine/endocrine disruption mechanisms.     

Comparison of biocompatibility of gel-derived bioactive ceramics in macrophage culture conditions

The behaviour of rat alveolar macrophages cultured in the presence of three new gel-derived ceramic biomaterials (CaO-P2O5-SiO2 system) with slightly different chemical compositions was examined. The abilities of these three materials to stimulate alveolar macrophages were compared. Non-treated and lipopolysaccharide-treated macrophages were used as control. The level of macrophage activation was determined by nitrite and prostaglandin E2 assay and respiratory burst measurement by chemiluminescence. The results of these studies showed different macrophage responses to these three relatively similar stimuli. Two of the studied materials were shown to be potent activators of respiratory burst and prostaglandin E2 secretion without any significant release of nitric oxide. On the contrary, the material characterized as the most surface reactive strongly affected only nitric oxide generation by the cells.     

Complement-dependent clearance of apoptotic cells by human macrophages

Apoptotic cells are rapidly engulfed by phagocytes, but the receptors and ligands responsible for this phenomenon are incompletely characterized. Previously described receptors on blood- derived macrophages have been characterized in the absence of serum and show a relatively low uptake of apoptotic cells. Addition of serum to the phagocytosis assays increased the uptake of apoptotic cells by more than threefold. The serum factors responsible for enhanced uptake were identified as complement components that required activation of both the classical pathway and alternative pathway amplification loop. Exposure of phosphatidylserine on the apoptotic cell surface was partially responsible for complement activation and resulted in coating the apoptotic cell surface with C3bi. In the presence of serum, the macrophage receptors for C3bi, CR3 (CD11b/CD18) and CR4 (CD11c/CD18), were significantly more efficient in the uptake of apoptotic cells compared with previously described receptors implicated in clearance. Complement activation is likely to be required for efficient uptake of apoptotic cells within the systemic circulation, and early component deficiencies could predispose to systemic autoimmunity by enhanced exposure to and/or aberrant deposition of apoptotic cells.     

Superoxide mediates cigarette smoke-induced infiltration of neutrophils into the airways through nuclear factor-kappaB activation and IL-8 mRNA expression in guinea pigs in vivo

We examined the hypothesis that superoxide mediates infiltration of neutrophils to the airways through nuclear factor (NF)-kappaB and interleukin-8 (IL-8) after acute exposure to cigarette smoke (CS) in vivo. Male Hartley strain guinea pigs were exposed to air or 20 puffs of CS and killed 5 h after the exposure. The differential cell count of bronchoalveolar lavage fluid and specific myeloperoxidase enzyme assay demonstrated that acute exposure to CS caused neutrophil accumulation to the airways and parenchyma, respectively. Acute exposure to CS increased DNA-binding activity of NF-kappaB in the lung. Acute exposure to CS also increased IL-8 messenger RNA (mRNA) expression in the lung. Pretreatment of guinea pigs with recombinant human superoxide dismutase (rhSOD) aerosols reduced the CS-induced neutrophil accumulation to the airways. Both activation of NF-kappaB and increased IL-8 mRNA expression were also inhibited by the pretreatment of rhSOD aerosols. Strong immunoreactivities for p65 and p50 were detected in the nuclei of alveolar macrophages after acute exposure to CS. The signal for IL-8 mRNA expression was demonstrated in the alveolar space after acute exposure to CS. Neither significant immunoreactivities for p65 and p50 nor IL-8 mRNA signals were observed in airway epithelium. These observations suggest that acute exposure to CS initiates superoxide-dependent mechanism that, through NF-kappaB activation and IL-8 mRNA expression, produces infiltration of neutrophils to the airways in vivo. It was also suggested that the alveolar macrophage is one potential source of NF-kappaB activation and IL-8 mRNA expression after acute exposure to CS.     

Protein rotational relaxation as studied by solvent 1H and 2H magnetic relaxation

Earlier studies of the magnetic field dependence of the nuclear spin magnetic relaxation rate of solvent protons in solutions of diamagnetic proteins have indicated that this dependence (called relaxation dispersion) is related to the rotational Brownian motion of solute proteins. In essence, the dispersion is such that 1/T1 (the proton spin-lattice relaxation rate) decreases monotonically as the magnetic field is increased from a very low value (approximately 10 Oe); the dispersion has a point of inflection at a value of magnetic field which depends on protein size, shape, concentration, temperature, and solvent composition. The value of the proton Larmor precession frequency nu(c) at the inflection field appears to relate to tau (R), the rotational relaxation time of the protein molecules. We have measured proton relaxation dispersions for solutions of various proteins that span a three-decade range of molecular weights, and for one sample of transfer ribonucleic acid. We have also measured deuteron relaxation dispersions for solutions of three proteins: lysozyme, carbonmonoxyhemoglobin, and Helix pomatia hemocyanin with molecular weight 900 000. A quantitative relationship between both proton and deuteron dispersion data and protein rotational relaxation is confirmed, and the point is made that magnetic dispersion measurements are of very general applicability for measuring the rotational relaxation rate of macromolecules in solution. It has been previously shown that the influence of proton motion on the relaxation behavior of the solvent is not due to exchange of solvent molecules between the bulk solvent and a hydration region of the protein. In the present paper, we suggest that the interaction results from a long range hydrodynamic effect fundamental to the situation of large Brownian particles in an essentially continuum fluid. The general features of the proposed mechanism are indicated, but no theoretical computations are presented.     

Retention of insoluble particles after local intrabronchial deposition in dogs

Recent studies have challenged the generally accepted hypothesis that bronchial particle clearance is complete within 24-48 h postdeposition. We studied bronchial retention of inert particles using a bronchoscope and microspray nozzle to localize deposition in a bronchus while avoiding alveolar deposition. Six-microliter aliquots (444 kBq) of submicrometer (number mean diameter = 0.22 microns, geometric standard deviation = 1.75) technetium-99m-labeled (99mTc) sulfur colloid (SC) particles (n = 6) or the unbound radiolabel 99mTc-pertechnetate (99mTcO4-; n = 3) were sprayed onto a 5-mm-diam bronchus in halothane-anesthetized dogs. Radioactivity at the deposition site and clearance pathway was monitored externally with a gamma camera beginning immediately postspray. Bronchial retention of SC was 8.5 +/- 2.4 and 1.5 +/- 0.7% at 3 and 24 h postspray, respectively. Tracheal mucus velocity was measured at 10.4 +/- 2.2 mm/min. For comparison, clearance of inhaled submicrometer SC particles was also measured in the same dogs. Retention of inhaled aerosolized SC (peripheral lung deposition) was 98.1 +/- 1.1 and 76.3 +/- 1.8% at 3 and 24 h, respectively. 99mTcO4- cleared from the bronchi slightly more rapidly than did SC. Radioactivity was readily detected in the blood after deposition of 99mTcO4- but not of SC. Thus SC cleared by mucociliary transport, whereas 99mTcO4- cleared predominantly by transepithelial absorption. We conclude that clearance of submicrometer particles from a 5-mm conducting airway is very nearly complete by 24 h, with approximately 92% of the clearance occurring within the first 3 h postdeposition.     

Interaction of lung surfactant protein A with alveolar macrophages

We analyzed the binding mechanism of human recombinant lung surfactant protein A (SP-A) to rat alveolar macrophages using anti-SP-A antiserum and protein A coated onto gold particles. Results were compared with our recent data on binding and uptake of SP-A-coated colloidal gold particles. The rationale for the current approach was to avoid any possible steric effects on SP-A binding to the cell surface. Binding of unlabeled SP-A depends on the presence of calcium ions in the medium and involves a mannose-specific mechanism. Binding is partly inhibited by the collagenase-resistant fragment of SP-A, representing mainly the globular part of SP-A. Taken together, these facts indicate binding of SP-A via the carbohydrate binding site on the globular region of SP-A. On the other hand, a partial inhibition of SP-A binding by fragments of C1q (representing the collagenous region of C1q) indicates a second binding site for SP-A by the collagen-like portion to the C1q receptor of macrophages. We conclude that two different mechanisms are probably involved in SP-A binding to alveolar macrophages. Specificity of the binding was shown with fluorescein-labeled SP-A. Binding was inhibited by an excess of unlabeled SP-A. Binding and uptake of SP-A are seen only with alveolar macrophages and not with other macrophage populations isolated from rat, such as liver macrophages (Kupffer cells), resident peritoneal macrophages, and peritoneal macrophages activated by Corynebacterium parvum. Therefore, binding sites for SP-A occur exclusively on alveolar macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)     

Carbon monoxide in alveolar air as an index of exposure to cigarette smoke

1. A rapid method for the analysis of CO in expired air has been developed, which is suitable for use in studies of smoking. 2. The Bohr equation has been used to calculate the mean alveolar CO partial pressure (PA,CO). 3. The values of PA,CO obtained are highly correlated with direct measurements of venous carboxyhaemoglobin (r = 0-96). 4. The method will distinguish between populations of smokers and non-smokers, and can allow the changes of CO in a smoker throughout a 12 h period to be followed. It provides a measure of the dose of cigarette smoke (vapour phase) that results from smoking a single cigarette.     

Infection by Mycobacterium tuberculosis promotes human alveolar macrophage apoptosis

The effect of Mycobacterium tuberculosis infection on the viability of healthy (control) human alveolar macrophages was evaluated by staining with ethidium homodimer and calcein to discriminate live from dead cells. Infection with M. tuberculosis H37Ra or H37Rv increased macrophage mortality at 6 days from the control level of 3.8% +/- 0.7% to 28.7% +/- 6.9% or 12.6% +/- 3.1%, respectively (P < 0.001 for comparisons of all conditions). A role for tumor necrosis factor alpha (TNF-alpha) in the M. tuberculosis-induced cytolysis of alveolar macrophages was demonstrated by increased cytotoxicity following the addition of exogenous TNF-alpha to the cultures and by enhancement of macrophage survival when M. tuberculosis-infected alveolar macrophages were treated with pentoxifylline or anti-TNF-alpha antibody. The cytolytic mechanism was determined to be apoptosis by the demonstration of a characteristic internucleosomal ladder of genomic DNA by agarose gel electrophoresis, by finding nuclear fragmentation and condensation by electron microscopy, and by in situ terminal transferase-mediated nick end labeling of fragmented DNA in alveolar macrophages infected with M. tuberculosis in vitro. The latter technique was employed to reveal extensive apoptosis within caseating granulomas from lung tissue samples from clinical tuberculosis cases. The induction of apoptosis in alveolar macrophages by M. tuberculosis may play a role in the macrophage-pathogen interaction of tuberculosis in vivo.