An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

Comparative physiology of rodent pulmonary macrophages: in vitro functional responses

1988 ◽  
Vol 64 (5) ◽  
pp. 1953-1959 ◽  
Author(s):  
D. B. Warheit ◽  
M. A. Hartsky ◽  
M. S. Stefaniak
Keyword(s):  
Guinea Pig ◽  
Phagocytic Activity ◽  
Lung Cells ◽  
Comparative Physiology ◽  
Functional Responses ◽  
Inhaled Particles ◽  
Pulmonary Macrophages ◽  
The One ◽  
Formyl Peptides

Since toxicological testing of inhaled materials frequently requires utilization of several species, we have investigated pulmonary macrophage (PM) functional responses and compared the rat model with other rodents. Two strains of rats, three strains of mice, and one strain each of hamster and guinea pig were used in this study. The numbers of recovered cells by bronchoalveolar lavage generally correlated with animal body weight. The one exception was the Syrian Golden hamster from which increased numbers of macrophages were recovered. Cellular differential data obtained from lavaged cytocentrifuge preparations demonstrated that PM's account for greater than 97% of recoverable free lung cells for all species except the guinea pig, which contains a resident population of eosinophils. Cell morphology studies indicated that hamster PM exhibited the highest proportion of ruffled PM and demonstrated the highest phagocytic activity, whereas mouse PM phagocytic activity was significantly reduced compared with the other three species. In addition, chemotaxis studies showed that rat PM migrated best to zymosan-activated, complement-dependent chemoattractants, whereas hamster PM demonstrated an enhanced chemotactic response to N-formyl peptides. The results of these studies suggest that the rat may be the most efficient species for clearing inhaled particles, whereas hamsters and guinea pigs may best respond to bacteria.

scholarly journals Ecosystem Screening Approach for Pathogen-Associated Microorganisms Affecting Host Disease

2011 ◽  
Vol 77 (17) ◽  
pp. 6069-6075 ◽  
Author(s):  
Eric Galiana ◽  
Antoine Marais ◽  
Catherine Mura ◽  
Benoît Industri ◽  
Gilles Arbiol ◽  
...  
Keyword(s):  
Microbial Community ◽  
Screening Method ◽  
Surface Shape ◽  
Host Disease ◽  
Content Type ◽  
Mutualistic Interaction ◽  
Definition Of ◽  
Associated Species

ABSTRACTThe microbial community in which a pathogen evolves is fundamental to disease outcome. Species interacting with a pathogen on the host surface shape the distribution, density, and genetic diversity of the inoculum, but the role of these species is rarely determined. The screening method developed here can be used to characterize pathogen-associated species affecting disease. This strategy involves three steps: (i) constitution of the microbial community, using the pathogen as a trap; (ii) community selection, using extracts from the pathogen as the sole nutrient source; and (iii) molecular identification and the screening of isolates focusing on their effects on the growth of the pathogenin vitroand host disease. This approach was applied to a soilborne plant pathogen,Phytophthora parasitica, structured in a biofilm, for screening the microbial community from the rhizosphere ofNicotiana tabacum(the host). Two of the characterized eukaryotes interfered with the oomycete cycle and may affect the host disease. AVorticellaspecies acted through a mutualistic interaction withP. parasitica, disseminating pathogenic material by leaving the biofilm. APhomaspecies established an amensal interaction withP. parasitica, strongly suppressing disease by inhibitingP. parasiticagermination. This screening method is appropriate for all nonobligate pathogens. It allows the definition of microbial species as promoters or suppressors of a disease for a given biotope. It should also help to identify important microbial relationships for ecology and evolution of pathogens.

scholarly journals Role of Adenylate Cyclase-Hemolysin in Alveolar Macrophage Apoptosis during Bordetella pertussis Infection In Vivo

1998 ◽  
Vol 66 (4) ◽  
pp. 1718-1725 ◽  
Author(s):  
Pascale Gueirard ◽  
Anne Druilhe ◽  
Marina Pretolani ◽  
Nicole Guiso
Keyword(s):  
Adenylate Cyclase ◽  
Bronchoalveolar Lavage ◽  
Bordetella Pertussis ◽  
Alveolar Macrophages ◽  
Apoptotic Cells ◽  
Neutrophil Accumulation ◽  
Pertussis Infection ◽  
Intranasal Infection

ABSTRACT Bordetella pertussis induces in vitro apoptosis of murine alveolar macrophages by a mechanism that is dependent on expression of bacterial adenylate cyclase-hemolysin. Using a murine respiratory model, we found in this study that intranasal infection with a parental B. pertussis strain, but not with an isogenic variant deficient in the expression of all toxins and adhesins, induced a marked neutrophil accumulation in the bronchoalveolar lavage fluid and an early decrease in macrophage numbers. These phenomena paralleled a time-dependent rise in the proportion of apoptotic nuclei, as detected by flow cytometry, and of macrophages which had engulfed apoptotic bodies. Apoptotic death of bronchopulmonary cells was observed exclusively following intranasal infection with bacteria reisolated from lungs of infected animals and not with B. pertussis collected after in vitro subculture. Using the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling technique coupled to fluorescence microscopy and morphological analysis, we established that the apoptotic cells in bronchoalveolar lavage fluids were neutrophils and macrophages. Histological analysis of the lung tissues from B. pertussis-infected mice showed increased numbers of apoptotic cells in the alveolar compartments. Cellular accumulation in bronchoalveolar lavage fluids and apoptosis of alveolar macrophages were significantly attenuated in mice infected with a mutant deficient in the expression of adenylate cyclase-hemolysin, indicating a role of this enzyme in these processes.

STUDY OF ACTIVATING EFFECT OF SURFACTANT DRUGS ON PULMONARY MACROPHAGES IN VITRO IN PATIENTS WITH BRONCHIECTASIS

2020 ◽  
pp. 5-8
Author(s):  
Dmitrii Valerevich Minukhin
Keyword(s):  
Cell Surface ◽  
Bronchoalveolar Lavage ◽  
Injury Rate ◽  
Exogenous Surfactant ◽  
Control Group ◽  
Electron Microscopic ◽  
Local Immunity ◽  
Surfactant System ◽  
Pulmonary Macrophages

The state of surfactant system of lungs in chronic inflammation is known to disrupt their structural organization, causes shifts in the system itself, the severity of which depends on alveolar parenchyma injury rate. The cell destruction of aerohematical barrier is accompanied by changes in pulmonary surfactant system, its deficiency, development of dis− and atelectases, which increases the severity of lung injury and promotes the progression of bronchiectasis. Exogenously introduced surfactant restores local immunity and serves as a substrate for synthesis of its own surfactant. To determine the stimulatory effect of natural surfactant on receptors of the lung macrophages and its influence on activation of phagocytosis a comparative study of direct effect of infasurf on cell surface and formation of phagocytic vacuoles in macrophage elements of individuals with bronchodectic disease at an acute stage was performed . In bronchoalveolar lavage of patients the percentage and viability of pulmonary macrophages were determined. Other lavage material was investigated both as a baseline control and with infasurf. The electron microscopic examination of bronchoalveolar lavage macrophage elements in patients show that after incubation of cells with infasurf, there is a pronounced cell surface activation, formation of phagocytic vacuoles containing membranes of exogenous surfactant. Its small and large clusters were often observed lying freely between pulmonary macrophages, whereas in the control group (without infasurf) small fragments of tubular myelin or osmiophilous lamellar bodies were noted. Thus, the specific pharmacological action of surfactant drugs directly contributes to differentiation and maturation of pulmonary macrophages, their phagocytic function activation. Key words: bronchiectasis, surfactant, pulmonary macrophages.

Use of Pulmonary Macrophages in Metal Toxicity: A Brief Overview

1989 ◽  
Vol 8 (7) ◽  
pp. 1247-1250
Author(s):  
Gerald L. Fisher
Keyword(s):  
Metal Toxicity ◽  
Pulmonary Toxicity ◽  
Critical Function ◽  
Cellular Toxicity ◽  
Effective Utilization ◽  
Advantages And Disadvantages ◽  
Pulmonary Damage ◽  
Pulmonary Macrophages

The pulmonary macrophage provides a critical function in the maintenance of the sterility and integrity of the lung. Inhaled particle deposited in the deep lung may interact directly with macrophages to manifest either primary cellular toxicity or secondary pulmonary damage resulting from impaired macrophage function. The advantages and disadvantages of in vitro macrophage culture systems as predictors of in vivo pulmonary toxicity are briefly described. Recommendations are presented for areas of additional research as well as effective utilization of this assay system.

scholarly journals Role of Copper Efflux in Pneumococcal Pathogenesis and Resistance to Macrophage-Mediated Immune Clearance

2015 ◽  
Vol 83 (4) ◽  
pp. 1684-1694 ◽  
Author(s):  
Michael D. L. Johnson ◽  
Thomas E. Kehl-Fie ◽  
Roger Klein ◽  
Jacqueline Kelly ◽  
Corinna Burnham ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Copper Stress ◽  
Mammalian Host ◽  
Bacterial Clearance ◽  
Content Type ◽  
Immune Clearance ◽  
Pulmonary Macrophages ◽  
Insight Into

In bacteria, the intracellular levels of metals are mediated by tightly controlled acquisition and efflux systems. This is particularly true of copper, a trace element that is universally toxic in excess. During infection, the toxic properties of copper are exploited by the mammalian host to facilitate bacterial clearance. To better understand the role of copper during infection, we characterized the contribution of thecopoperon to copper homeostasis and virulence inStreptococcus pneumoniae. Deletion of either the exporter, encoded bycopA, or the chaperone, encoded bycupA, led to hypersensitivity to copper stress. We further demonstrated that loss of the copper exporter encoded bycopAled to decreased virulence in pulmonary, intraperitoneal, and intravenous models of infection. Deletion ofcopAresulted in enhanced macrophage-mediated bacterial clearancein vitro. The attenuation phenotype of thecopAmutant in the lung was found to be dependent on pulmonary macrophages, underscoring the importance of copper efflux in evading immune defenses. Overall, these data provide insight into the role of thecopoperon in pneumococcal pathogenesis.

scholarly journals The Scavenger Receptor MARCO Is Required for Lung Defense against Pneumococcal Pneumonia and Inhaled Particles

2004 ◽  
Vol 200 (2) ◽  
pp. 267-272 ◽  
Author(s):  
Mohamed Arredouani ◽  
Zhiping Yang ◽  
YaoYu Ning ◽  
Guozhong Qin ◽  
Raija Soininen ◽  
...  
Keyword(s):  
Pneumococcal Pneumonia ◽  
Inflammatory Responses ◽  
Scavenger Receptor ◽  
Pneumococcal Infection ◽  
Innate Defense ◽  
Inhaled Particles ◽  
Lung Defense

Alveolar macrophages (AMs) express the class A scavenger receptor macrophage receptor with collagenous structure (MARCO), but its role in vivo in lung defense against bacteria and environmental particles has not been studied. We used MARCO-deficient mice to directly test the in vivo role of AM MARCO in innate defense against pneumococcal infection and environmental particles. In a murine model of pneumococcal pneumonia, MARCO−/− mice displayed an impaired ability to clear bacteria from the lungs, increased pulmonary inflammation and cytokine release, and diminished survival. In vitro binding of Streptococcus pneumoniae and in vivo uptake of unopsonized particles by MARCO−/− AMs were dramatically impaired. MARCO−/− mice treated with the “inert” environmental particle TiO2 showed enhanced inflammation and chemokine expression, indicating that MARCO-mediated clearance of inert particles by AMs prevents inflammatory responses otherwise initiated by other lung cells. Our findings point to an important role of MARCO in mounting an efficient and appropriately regulated innate immune response against inhaled particles and airborne pathogens.

scholarly journals CSF1R inhibition prevents radiation pulmonary fibrosis by depletion of interstitial macrophages

2018 ◽  
Vol 51 (3) ◽  
pp. 1702120 ◽  
Author(s):  
Lydia Meziani ◽  
Michele Mondini ◽  
Benoît Petit ◽  
Alexandre Boissonnas ◽  
Vincent Thomas de Montpreville ◽  
...  
Keyword(s):  
Preclinical Model ◽  
T Helper ◽  
Pulmonary Macrophages ◽  
Radiation Induced ◽  
Tissue Lysate ◽  
Lung Biopsies ◽  
Th1 Cytokines ◽  
Stimulating Factor

Radiation-induced lung fibrosis (RIF) is a delayed side-effect of chest radiotherapy, frequently associated with macrophage infiltration.We aimed to characterise the role of pulmonary macrophages in RIF using human lung biopsies from patients receiving radiotherapy for thorax malignancies and a RIF model developed in C57BL/6 mice after 16-Gy thorax irradiation.High numbers of macrophages (both interstitial and alveolar) were detected in clinical and preclinical RIF. In the preclinical model, upregulation of T-helper (Th)2 cytokines was measured, whereas Th1 cytokines were downregulated in RIF tissue lysate. Bronchoalveolar lavage demonstrated upregulation of both types of cytokines. At steady state, tissue-infiltrating macrophages (IMs) expressed 10-fold more arginase (Arg)-1 than alveolar macrophages (AMs), and a 40-fold upregulation of Arg-1 was found in IMs isolated from RIF. IMs, but not AMs, were able to induce myofibroblast activation in vitro. In addition, whereas depletion of AMs using Clodrosome didn't affect RIF score, depletion of IMs using a clinically available colony-stimulating factor receptor-1 (CSF1R) neutralising antibody was antifibrotic.These findings suggest differential contributions of alveolar versus interstitial macrophages in RIF, highlighting the fibrogenic role of IMs. The CSF1/CSF1R pathway was identified as a new therapeutic target to inhibit RIF.

Role of platelet serotonin in the canine pulmonary response to endotoxin

1981 ◽  
Vol 50 (1) ◽  
pp. 178-184 ◽  
Author(s):  
T. L. Murphy ◽  
R. C. Allison ◽  
I. M. Weisman ◽  
D. R. McCaffree ◽  
B. A. Gray
Keyword(s):  
Platelet Count ◽  
Pulmonary Artery ◽  
Dynamic Compliance ◽  
Positive Control ◽  
Pulmonary Response ◽  
Bovine Collagen ◽  
Platelet Serotonin ◽  
Rapid Injection

There is evidence suggesting a role for platelet serotonin (5-HT) in the immediate pulmonary response to endotoxin in the dog (J. Appl. Physiol. 23: 47, 1967). To further define this role, autologous canine platelets were labeled with 5-[14C]HT in vitro and then reinfused. Subsequently Escherichia coli endotoxin (0.55:B-5, Difco), 2.5 mg/kg, was injected. Within 5 min dynamic compliance (CL) fell by more than 50%, and nonelastic resistance (RL) increased by more than 200%. Despite a 95% decrease in platelet count, less than 10% of the platelet 5-HT was released as determined by changes in the radioactivity of platelet-poor plasma (PPP) prepared from both aortic and pulmonary artery blood. As a positive control, injected of bovine collagen produced a similar decrease in platelet count that was associated with a significant increase in the radioactivity of aortic and pulmonary artery PPP. FInally, rapid injection of a dose of 5-HT equivalent to 25% of the 5-HT in circulating platelets did not cause a change in CL or RL equivalent to that produced by endotoxin. From these data we conclude that endotoxin injection does not cause immediate massive platelet activation and that platelet 5-HT does not play a major role in the immediate pulmonary response to endotoxin.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

Sign in / Sign up

Export Citation Format

Share Document