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Sample records for lung epithelia model

  1. Glucocorticoids Regulate Tight Junction Permeability of Lung Epithelia by Modulating Claudin 8.

    PubMed

    Kielgast, Felix; Schmidt, Hanna; Braubach, Peter; Winkelmann, Veronika E; Thompson, Kristin E; Frick, Manfred; Dietl, Paul; Wittekindt, Oliver H

    2016-05-01

    The lung epithelium constitutes a selective barrier that separates the airways from the aqueous interstitial compartment. Regulated barrier function controls water and ion transport across the epithelium and is essential for maintaining lung function. Tight junctions (TJs) seal the epithelial barrier and determine the paracellular transport. The properties of TJs depend especially on their claudin composition. Steroids are potent drugs used to treat a variety of airway diseases. Therefore, we addressed whether steroid hormones directly act on TJ properties in lung epithelia. Primary human tracheal epithelial cells and NCI-H441 cells, both cultivated under air-liquid interface conditions, were used as epithelial cell models. Our results demonstrate that glucocorticoids, but not mineralocorticoids, decreased paracellular permeability and shifted the ion permselectivity of TJs toward Cl(-). Glucocorticoids up-regulated claudin 8 (cldn8) expression via glucocorticoid receptors. Silencing experiments revealed that cldn8 is necessary to recruit occludin at the TJs. Immunohistochemistry on human lung tissue showed that cldn8 is specifically expressed in resorptive epithelia of the conducting and respiratory airways but not in the alveolar epithelium. We conclude that glucocorticoids enhance lung epithelia barrier function and increase paracellular Cl(-) selectivity via modulation of cldn8-dependent recruitment of occludin at the TJs. This mode of glucocorticoid action on lung epithelia might be beneficial to patients who suffer from impaired lung barrier function in various diseased conditions. PMID:26473470

  2. Next Generation Respiratory Viral Vaccine System: Advanced and Emerging Bioengineered Human Lung Epithelia Model (HLEM) Organoid Technology

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas J.; Schneider, Sandra L.; MacIntosh, Victor; Gibbons, Thomas F.

    2010-01-01

    Acute respiratory infections, including pneumonia and influenza, are the S t" leading cause of United States and worldwide deaths. Newly emerging pathogens signaled the need for an advanced generation of vaccine technology.. Human bronchial-tracheal epithelial tissue was bioengineered to detect, identify, host and study the pathogenesis of acute respiratory viral disease. The 3-dimensional (3D) human lung epithelio-mesechymal tissue-like assemblies (HLEM TLAs) share characteristics with human respiratory epithelium: tight junctions, desmosomes, microvilli, functional markers villin, keratins and production of tissue mucin. Respiratory Syntial Virus (RSV) studies demonstrate viral growth kinetics and membrane bound glycoproteins up to day 20 post infection in the human lung-orgainoid infected cell system. Peak replication of RSV occurred on day 10 at 7 log10 particles forming units per ml/day. HLEM is an advanced virus vaccine model and biosentinel system for emergent viral infectious diseases to support DoD global surveillance and military readiness.

  3. Telomerase expression in noncancerous bronchial epithelia is a possible marker of early development of lung cancer.

    PubMed

    Miyazu, Yuka Matsuoka; Miyazawa, Teruomi; Hiyama, Keiko; Kurimoto, Noriaki; Iwamoto, Yasuo; Matsuura, Hiroo; Kanoh, Koji; Kohno, Nobuoki; Nishiyama, Masahiko; Hiyama, Eiso

    2005-11-01

    Centrally located lung cancers in smokers frequently associated with subsequent primary tumors. We evaluated the telomerase expression chronologically in noncancerous epithelia as a risk factor of susceptibility to lung cancer development. Telomerase protein expression was examined in situ by immunohistochemistry in 26 noncancerous bronchial epithelia adjacent to centrally located early-stage lung cancers in sequential 23 patients treated by photodynamic therapy or surgery among 206 patients who underwent autofluorescence bronchoscopy from 1997 to 2003. Among the 15 lesions in 12 patients treated by photodynamic therapy alone, 11 lesions achieved complete remission after photodynamic therapy, and none of their noncancerous bronchial epithelia was telomerase positive. On the contrary, in the remaining four lesions, either recurrence or secondary lung cancer developed adjacent to the successfully treated primary cancer within 26 months, and the telomerase protein expression in noncancerous epithelia was detected before the secondary cancer development (P < 0.001). The overall relationship of human telomerase reverse transcriptase positivity in noncancerous epithelia and subsequent lung cancer development, including patients treated by radiation or surgery, showed higher significance (P < 0.0001). Histologically "normal" bronchial epithelia in smokers may unphysiologically express telomerase as a field, and such epithelia are likely susceptible to develop lung cancer. We propose that ectopic expression of telomerase in bronchial epithelia may precede transformation in human lung cancer development and that detection of telomerase protein in noncancerous bronchial epithelia will become a useful marker detecting high-risk patients for lung cancer development. PMID:16266979

  4. Value of Organoids from Comparative Epithelia Models.

    PubMed

    Schwarz, Julia S; de Jonge, Hugo R; Forrest, John N

    2015-12-01

    Organoids have tremendous therapeutic potential. They were recently defined as a collection of organ-specific cell types, which self-organize through cell-sorting, develop from stem cells, and perform an organ specific function. The ability to study organoid development and growth in culture and manipulate their genetic makeup makes them particularly suitable for studying development, disease, and drug efficacy. Organoids show great promise in personalized medicine. From a single patient biopsy, investigators can make hundreds of organoids with the genetic landscape of the patient of origin. This genetic similarity makes organoids an ideal system in which to test drug efficacy. While many investigators assume human organoids are the ultimate model system, we believe that the generation of epithelial organoids of comparative model organisms has great potential. Many key transport discoveries were made using marine organisms. In this paper, we describe how deriving organoids from the spiny dogfish shark, zebrafish, and killifish can contribute to the fields of comparative biology and disease modeling with future prospects for personalized medicine. PMID:26604860

  5. Value of Organoids from Comparative Epithelia Models

    PubMed Central

    Schwarz, Julia S.; de Jonge, Hugo R.; Forrest, John N.

    2015-01-01

    Organoids have tremendous therapeutic potential. They were recently defined as a collection of organ-specific cell types, which self-organize through cell-sorting, develop from stem cells, and perform an organ specific function. The ability to study organoid development and growth in culture and manipulate their genetic makeup makes them particularly suitable for studying development, disease, and drug efficacy. Organoids show great promise in personalized medicine. From a single patient biopsy, investigators can make hundreds of organoids with the genetic landscape of the patient of origin. This genetic similarity makes organoids an ideal system in which to test drug efficacy. While many investigators assume human organoids are the ultimate model system, we believe that the generation of epithelial organoids of comparative model organisms has great potential. Many key transport discoveries were made using marine organisms. In this paper, we describe how deriving organoids from the spiny dogfish shark, zebrafish, and killifish can contribute to the fields of comparative biology and disease modeling with future prospects for personalized medicine. PMID:26604860

  6. Computational model for the regulation of extracellular ATP and adenosine in airway epithelia.

    PubMed

    Garcia, Guilherme J M; Picher, Maryse; Zuo, Peiying; Okada, Seiko F; Lazarowski, Eduardo R; Button, Brian; Boucher, Richard C; Elston, Tim C

    2011-01-01

    Extracellular nucleotides are key components of the signaling network regulating airway clearance. They are released by the epithelium into the airway surface liquid (ASL) to stimulate cilia beating activity, mucus secretion and airway hydration. Understanding the factors affecting their availability for purinoceptor activation is an important step toward the development of new therapies for obstructive lung diseases. This chapter presents a mathematical model developed to gain predictive insights into the regulation of ASL nucleotide concentrations on human airway epithelia. The parameters were estimated from experimental data collected on polarized primary cultures of human nasal and bronchial epithelial cells. This model reproduces major experimental observations: (1) the independence of steady-state nucleotide concentrations on ASL height, (2) the impact of selective ectonucleotidase inhibitors on their steady-state ASL concentrations, (3) the changes in ASL composition caused by mechanical stress mimicking normal breathing, (4) and the differences in steady-state concentrations existing between nasal and bronchial epithelia. In addition, this model launched the study of nucleotide release into uncharted territories, which led to the discovery that airway epithelia release, not only ATP, but also ADP and AMP. This study shows that computational modeling, coupled to experimental validation, provides a powerful approach for the identification of key therapeutic targets for the improvement of airway clearance in obstructive respiratory diseases. PMID:21560044

  7. Abnormal expression of CCND1 and RB1 in resection margin epithelia of lung cancer patients.

    PubMed Central

    Betticher, D. C.; Heighway, J.; Thatcher, N.; Hasleton, P. S.

    1997-01-01

    Tumours develop through the accumulation of genetic alterations associated with a progressive increase of the malignant phenotype. In lung cancer, chronic exposure of bronchial epithelium to carcinogens in cigarette smoke may lead to multiple dysplastic and hyperplastic lesions scattered throughout the tracheobronchial tree. Little is known about the genetic alterations in such lesions. This study was carried out to examine cyclin D1 (CCND1) and retinoblastoma (RB1) gene expression in the bronchial epithelium of patients with lung cancer. Lung tumours and their corresponding tumour-free resection margins from 33 patients who underwent resection of non-small-cell lung cancer (NSCLC) were examined by immunostaining with monoclonal antibodies against cyclin D1 (DCS-6; Novocastra) and pRb (NCL Rb-1; Novocastra). Examination of the resection margins revealed four carcinomas in situ, 19 hyperplasias and ten sections showing apparently normal bronchial epithelium. A control group of patients, without lung tumours and who had never smoked, revealed no or weak cyclin D1 and positive pRb staining within bronchial epithelia. Increased cyclin D1 and diminished pRb expression were found in 76% (n = 25) and 27% (n = 9) of the resection margins respectively, and in 12% (n = 4) both cyclin D1 and pRb expression were altered. In the corresponding tumours, 48% (n = 16) were normal, while altered expression was found for cyclin D1 in 33% (n = 11), pRb in 27% (n = 9) and both in 9% (n = 3) of cases. It appears that altered expression of cyclin D1 and pRb is an early event in NSCLC development in almost half of cases analysed. Further investigations are needed to determine the significance of immunostaining of bronchial specimens in individuals at risk of lung cancer, with the possibility that the observations are of importance in the early diagnosis of NSCLC. Images Figure 1 PMID:9192978

  8. Adenoviral gene transfer corrects the ion transport defect in the sinus epithelia of a porcine CF model.

    PubMed

    Potash, Andrea E; Wallen, Tanner J; Karp, Philip H; Ernst, Sarah; Moninger, Thomas O; Gansemer, Nicholas D; Stoltz, David A; Zabner, Joseph; Chang, Eugene H

    2013-05-01

    Cystic fibrosis (CF) pigs spontaneously develop sinus and lung disease resembling human CF. The CF pig presents a unique opportunity to use gene transfer to test hypotheses to further understand the pathogenesis of CF sinus disease. In this study, we investigated the ion transport defect in the CF sinus and found that CF porcine sinus epithelia lack cyclic AMP (cAMP)-stimulated anion transport. We asked whether we could restore CF transmembrane conductance regulator gene (CFTR) current in the porcine CF sinus epithelia by gene transfer. We quantified CFTR transduction using an adenovirus expressing CFTR and green fluorescent protein (GFP). We found that as little as 7% of transduced cells restored 6% of CFTR current with 17-28% of transduced cells increasing CFTR current to 50% of non-CF levels. We also found that we could overcorrect cAMP-mediated current in non-CF epithelia. Our findings indicate that CF porcine sinus epithelia lack anion transport, and a relatively small number of cells expressing CFTR are required to rescue the ion transport phenotype. These studies support the use of the CF pig as a preclinical model for future gene therapy trials in CF sinusitis. PMID:23511247

  9. Human cystic fibrosis airway epithelia have reduced Cl- conductance but not increased Na+ conductance.

    PubMed

    Itani, Omar A; Chen, Jeng-Haur; Karp, Philip H; Ernst, Sarah; Keshavjee, Shaf; Parekh, Kalpaj; Klesney-Tait, Julia; Zabner, Joseph; Welsh, Michael J

    2011-06-21

    Loss of cystic fibrosis transmembrane conductance regulator (CFTR) anion channel function causes cystic fibrosis (CF) lung disease. CFTR is expressed in airway epithelia, but how CF alters electrolyte transport across airway epithelia has remained uncertain. Recent studies of a porcine model showed that in vivo, excised, and cultured CFTR(-/-) and CFTR(ΔF508/ΔF508) airway epithelia lacked anion conductance, and they did not hyperabsorb Na(+). Therefore, we asked whether Cl(-) and Na(+) conductances were altered in human CF airway epithelia. We studied differentiated primary cultures of tracheal/bronchial epithelia and found that transepithelial conductance (Gt) under basal conditions and the cAMP-stimulated increase in Gt were markedly attenuated in CF epithelia compared with non-CF epithelia. These data reflect loss of the CFTR anion conductance. In CF and non-CF epithelia, the Na(+) channel inhibitor amiloride produced similar reductions in Gt and Na(+) absorption, indicating that Na(+) conductance in CF epithelia did not exceed that in non-CF epithelia. Consistent with previous reports, adding amiloride caused greater reductions in transepithelial voltage and short-circuit current in CF epithelia than in non-CF epithelia; these changes are attributed to loss of a Cl(-) conductance. These results indicate that Na(+) conductance was not increased in these cultured CF tracheal/bronchial epithelia and point to loss of anion transport as key to airway epithelial dysfunction in CF. PMID:21646513

  10. Human cystic fibrosis airway epithelia have reduced Cl− conductance but not increased Na+ conductance

    PubMed Central

    Itani, Omar A.; Chen, Jeng-Haur; Karp, Philip H.; Ernst, Sarah; Keshavjee, Shaf; Parekh, Kalpaj; Klesney-Tait, Julia; Zabner, Joseph; Welsh, Michael J.

    2011-01-01

    Loss of cystic fibrosis transmembrane conductance regulator (CFTR) anion channel function causes cystic fibrosis (CF) lung disease. CFTR is expressed in airway epithelia, but how CF alters electrolyte transport across airway epithelia has remained uncertain. Recent studies of a porcine model showed that in vivo, excised, and cultured CFTR−/− and CFTRΔF508/ΔF508 airway epithelia lacked anion conductance, and they did not hyperabsorb Na+. Therefore, we asked whether Cl− and Na+ conductances were altered in human CF airway epithelia. We studied differentiated primary cultures of tracheal/bronchial epithelia and found that transepithelial conductance (Gt) under basal conditions and the cAMP-stimulated increase in Gt were markedly attenuated in CF epithelia compared with non-CF epithelia. These data reflect loss of the CFTR anion conductance. In CF and non-CF epithelia, the Na+ channel inhibitor amiloride produced similar reductions in Gt and Na+ absorption, indicating that Na+ conductance in CF epithelia did not exceed that in non-CF epithelia. Consistent with previous reports, adding amiloride caused greater reductions in transepithelial voltage and short-circuit current in CF epithelia than in non-CF epithelia; these changes are attributed to loss of a Cl− conductance. These results indicate that Na+ conductance was not increased in these cultured CF tracheal/bronchial epithelia and point to loss of anion transport as key to airway epithelial dysfunction in CF. PMID:21646513

  11. Dual Oxidase 2 in Lung Epithelia Is Essential for Hyperoxia-Induced Acute Lung Injury in Mice

    PubMed Central

    Kim, Min-Ji; Ryu, Jae-Chan; Kwon, Younghee; Lee, Suhee; Bae, Yun Soo; Yoon, Joo-Heon

    2014-01-01

    Abstract Aims: Acute lung injury (ALI) induced by excessive hyperoxia has been employed as a model of oxidative stress imitating acute respiratory distress syndrome. Under hyperoxic conditions, overloading quantities of reactive oxygen species (ROS) are generated in both lung epithelial and endothelial cells, leading to ALI. Some NADPH oxidase (NOX) family enzymes are responsible for hyperoxia-induced ROS generation in lung epithelial and endothelial cells. However, the molecular mechanisms of ROS production in type II alveolar epithelial cells (AECs) and ALI induced by hyperoxia are poorly understood. Results: In this study, we show that dual oxidase 2 (DUOX2) is a key NOX enzyme that affects hyperoxia-induced ROS production, particularly in type II AECs, leading to lung injury. In DUOX2 mutant mice (DUOX2thyd/thyd) or mice in which DUOX2 expression is knocked down in the lungs, hyperoxia-induced ALI was significantly lower than in wild-type (WT) mice. DUOX2 was mainly expressed in type II AECs, but not endothelial cells, and hyperoxia-induced ROS production was markedly reduced in primary type II AECs isolated from DUOX2thyd/thyd mice. Furthermore, DUOX2-generated ROS are responsible for caspase-mediated cell death, inducing ERK and JNK phophorylation in type II AECs. Innovation: To date, no role for DUOX2 has been defined in hyperoxia-mediated ALI despite it being a NOX homologue and major ROS source in lung epithelium. Conclusion: Here, we present the novel finding that DUOX2-generated ROS induce AEC death, leading to hyperoxia-induced lung injury. Antioxid. Redox Signal. 21, 1803–1818. PMID:24766345

  12. In vitro preparation of newt inner ear sensory epithelia as a model for repair and regeneration.

    PubMed

    Taylor, Ruth R

    2015-01-01

    The sensory "hair" cells of the inner ear transform sound energy into electrical signals, but are readily lost through aging, excessive noise, and ototoxic agents. The newt provides an excellent model in which to explore regeneration and whilst loss of hair cells from inner ear epithelia does not require whole organ regeneration, new hair cells are generated from differentiated supporting cells that transdifferentiate without an intervening mitotic event. Here we describe the methods for maintaining the sensory epithelia in long term culture; for the use of the aminoglycoside, gentamicin, to kill the hair cells; and for the examination of the tissue by electron microscopy or fluorescence microscopy. Demembranation of the epithelium reveals the underlying ultrastructure of the tissue for examination by scanning electron microscopy (SEM) and is a technique that can be utilized with immunogold labelling. PMID:25740492

  13. Models of coupled salt and water transport across leaky epithelia.

    PubMed

    Weinstein, A M; Stephenson, J L

    1981-05-15

    A general formulation is presented for the verification of isotonic transport and for the assignment of a degree of osmotic coupling in any epithelial model. In particular, it is shown that the concentration of the transported fluid in the presence of exactly equal bathing media is, in general, not a sufficient calculation by which to decide the issue of isotonicity of transport. Within this framework, two epithelial models are considered: (1) A nonelectrolyte compartment model of the lateral intercellular space is presented along with its linearization about the condition of zero flux. This latter approximate model is shown to be useful in the estimation of deviation from isotonicity, intraepithelial solute polarization effects, and the capacity to transport water against a gradient. In the case of uphill water transport, some limitations of a model of fixed geometry are indicated and the advantage of modeling a compliant interspace is suggested. (2) A comprehensive model of cell and channel is described which includes the major electrolytes and the possible presence of intraepithelial gradients. The general approach to verification of isotonicity is illustrated for this numerical model. In addition, the insights about parameter dependence gained from the linear compartment model are shown to be applicable to understanding this large simulation. PMID:6264088

  14. Modelling apical constriction in epithelia using elastic shell theory.

    PubMed

    Jones, Gareth Wyn; Chapman, S Jonathan

    2010-06-01

    Apical constriction is one of the fundamental mechanisms by which embryonic tissue is deformed, giving rise to the shape and form of the fully-developed organism. The mechanism involves a contraction of fibres embedded in the apical side of epithelial tissues, leading to an invagination or folding of the cell sheet. In this article the phenomenon is modelled mechanically by describing the epithelial sheet as an elastic shell, which contains a surface representing the continuous mesh formed from the embedded fibres. Allowing this mesh to contract, an enhanced shell theory is developed in which the stiffness and bending tensors of the shell are modified to include the fibres' stiffness, and in which the active effects of the contraction appear as body forces in the shell equilibrium equations. Numerical examples are presented at the end, including the bending of a plate and a cylindrical shell (modelling neurulation) and the invagination of a spherical shell (modelling simple gastrulation). PMID:19859751

  15. The Non-Proliferative Nature of Ascidian Folliculogenesis as a Model of Highly Ordered Cellular Topology Distinct from Proliferative Epithelia

    PubMed Central

    Azzag, Karim; Chelin, Yoann; Rousset, François; Le Goff, Emilie; Martinand-Mari, Camille; Martinez, Anne-Marie; Maurin, Bernard; Daujat-Chavanieu, Martine; Godefroy, Nelly; Averseng, Julien; Mangeat, Paul; Baghdiguian, Stephen

    2015-01-01

    Previous studies have addressed why and how mono‐stratified epithelia adopt a polygonal topology. One major additional, and yet unanswered question is how the frequency of different cell shapes is achieved and whether the same distribution applies between non-proliferative and proliferative epithelia. We compared different proliferative and non-proliferative epithelia from a range of organisms as well as Drosophila melanogaster mutants, deficient for apoptosis or hyperproliferative. We show that the distribution of cell shapes in non‐proliferative epithelia (follicular cells of five species of tunicates) is distinctly, and more stringently organized than proliferative ones (cultured epithelial cells and Drosophila melanogaster imaginal discs). The discrepancy is not supported by geometrical constraints (spherical versus flat monolayers), number of cells, or apoptosis events. We have developed a theoretical model of epithelial morphogenesis, based on the physics of divided media, that takes into account biological parameters such as cell‐cell contact adhesions and tensions, cell and tissue growth, and which reproduces the effects of proliferation by increasing the topological heterogeneity observed experimentally. We therefore present a model for the morphogenesis of epithelia where, in a proliferative context, an extended distribution of cell shapes (range of 4 to 10 neighbors per cell) contrasts with the narrower range of 5-7 neighbors per cell that characterizes non proliferative epithelia. PMID:26000769

  16. Cadmium-mediated toxicity of lung epithelia is enhanced through NF-κB-mediated transcriptional activation of the human zinc transporter ZIP8

    PubMed Central

    Napolitano, Jessica R.; Liu, Ming-Jie; Bao, Shengying; Crawford, Melissa; Nana-Sinkam, Patrick; Cormet-Boyaka, Estelle

    2012-01-01

    Cadmium (Cd), a toxic heavy metal and carcinogen that is abundantly present in cigarette smoke, is a cause of smoking-induced lung disease. SLC39A8 (ZIP8), a zinc transporter, is a major portal for Cd uptake into cells. We have recently identified that ZIP8 expression is under the transcriptional control of the NF-κB pathway. On the basis of this, we hypothesized that cigarette-smoke induced inflammation would increase ZIP8 expression in lung epithelia, thereby enhancing Cd uptake and cell toxicity. Herein we report that ZIP8 is a central mediator of Cd-mediated toxicity. TNF-α treatment of primary human lung epithelia and A549 cells induced ZIP8 expression, resulting in significantly higher cell death attributable to both apoptosis and necrosis following Cd exposure. Inhibition of the NF-κB pathway and ZIP8 expression significantly reduced cell toxicity. Zinc (Zn), a known cytoprotectant, prevented Cd-mediated cell toxicity via ZIP8 uptake. Consistent with cell culture findings, a significant increase in ZIP8 mRNA and protein expression was observed in the lung of chronic smokers compared with nonsmokers. From these studies, we conclude that ZIP8 expression is induced in lung epithelia in an NF-κB-dependent manner, thereby resulting in increased cell death in the presence of Cd. From this we contend that ZIP8 plays a critical role at the interface between micronutrient (Zn) metabolism and toxic metal exposure (Cd) in the lung microenvironment following cigarette smoke exposure. Furthermore, dietary Zn intake, or a lack thereof, may be a contributing factor in smoking-induced lung disease. PMID:22345571

  17. Protection of Cftr knockout mice from acute lung infection by a helper-dependent adenoviral vector expressing Cftr in airway epithelia

    PubMed Central

    Koehler, David R.; Sajjan, Umadevi; Chow, Yu-Hua; Martin, Bernard; Kent, Geraldine; Tanswell, A. Keith; McKerlie, Colin; Forstner, Janet F.; Hu, Jim

    2003-01-01

    We developed a helper-dependent adenoviral vector for cystic fibrosis lung gene therapy. The vector expresses cystic fibrosis transmembrane conductance regulator (Cftr) using control elements from cytokeratin 18. The vector expressed properly localized CFTR in cultured cells and in the airway epithelia of mice. Cftr RNA and protein were present in whole lung and bronchioles, respectively, for 28 days after a vector dose. Acute inflammation was minimal to moderate. To test the therapeutic potential of the vector, we challenged mice with a clinical strain of Burkholderia cepacia complex (Bcc). Cftr knockout mice (but not Cftr+/+ littermates) challenged with Bcc developed severe lung histopathology and had high lung bacteria counts. Cftr knockout mice receiving gene therapy 7 days before Bcc challenge had less severe histopathology, and the number of lung bacteria was reduced to the level seen in Cftr+/+ littermates. These data suggest that gene therapy could benefit cystic fibrosis patients by reducing susceptibility to opportunistic pathogens. PMID:14673110

  18. Protection of Cftr knockout mice from acute lung infection by a helper-dependent adenoviral vector expressing Cftr in airway epithelia.

    PubMed

    Koehler, David R; Sajjan, Umadevi; Chow, Yu-Hua; Martin, Bernard; Kent, Geraldine; Tanswell, A Keith; McKerlie, Colin; Forstner, Janet F; Hu, Jim

    2003-12-23

    We developed a helper-dependent adenoviral vector for cystic fibrosis lung gene therapy. The vector expresses cystic fibrosis transmembrane conductance regulator (Cftr) using control elements from cytokeratin 18. The vector expressed properly localized CFTR in cultured cells and in the airway epithelia of mice. Cftr RNA and protein were present in whole lung and bronchioles, respectively, for 28 days after a vector dose. Acute inflammation was minimal to moderate. To test the therapeutic potential of the vector, we challenged mice with a clinical strain of Burkholderia cepacia complex (Bcc). Cftr knockout mice (but not Cftr+/+ littermates) challenged with Bcc developed severe lung histopathology and had high lung bacteria counts. Cftr knockout mice receiving gene therapy 7 days before Bcc challenge had less severe histopathology, and the number of lung bacteria was reduced to the level seen in Cftr+/+ littermates. These data suggest that gene therapy could benefit cystic fibrosis patients by reducing susceptibility to opportunistic pathogens. PMID:14673110

  19. APICAL LOCATION OF FERROPORTIN 1 IN AIRWAY EPITHELIA AND ITS ROLE IN IRON DETOXIFICATION IN THE LUNG

    EPA Science Inventory

    Ferroportin 1 (FPN1; aka MTP1, IREG1, and SLC40A1), which was originally identified as a basolateral iron transporter crucial for nutritional iron absorption in the intestine, is expressed in airway epithelia and upregulated when these cells are exposed to iron. Using immunofluor...

  20. Primary cultured cells as sensitive in vitro model for assessment of toxicants--comparison to hepatocytes and gill epithelia.

    PubMed

    Zhou, Bingsheng; Liu, Chunsheng; Wang, Jingxian; Lam, Paul K S; Wu, Rudolf S S

    2006-11-16

    In an effort to develop cultured cell models for toxicity screening and environmental biomonitoring, we compared primary cultured gill epithelia and hepatocytes from freshwater tilapia (Oreochromis niloticus) to assess their sensitivity to AhR agonist toxicants. Epithelia were cultured on permeable supports (terephthalate membranes, "filters") and bathed on the apical with waterborne toxicants (pseudo in vivo asymmetrical culture conditions). Hepatocytes were cultured in multi-well plates and exposed to toxicants in culture medium. Cytochrome P4501A (measured as 7-Ethoxyresorufin-O-deethylase, EROD) was selected as a biomarker. For cultured gill epithelia, the integrity of the epithelia remained unchanged on exposure to model toxicants, such as 1,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene B[a]P, polychlorinated biphenyl (PCB) mixture (Aroclor 1254), and polybrominated diphenyl ether (PBDE) mixture (DE71). A good concentration-dependent response of EROD activity was clearly observed in both cultured gill epithelia and hepatocytes. The time-course response of EROD was measured as early as 3h, and was maximal after 6h of exposure to TCDD, B[a]P and Aroclor 1254. The estimated 6h EC50 for TCDD, B[a]P, and Aroclor 1254 was 1.2 x 10(-9), 5.7 x 10(-8) and 6.6 x 10(-6)M. For the cultured hepatocytes, time-course study showed that a significant induction of EROD took place at 18 h, and the maximal induction of EROD was observed at 24h after exposure. The estimated 24h EC50 for TCDD, B[a]P, and Aroclor 1254 was 1.4 x 10(-9), 8.1 x 10(-8) and 7.3 x 10(-6)M. There was no induction or inhibition of EROD in DE71 exposure to both gill epithelia and hepatocytes. The results show that cultured gill epithelia more rapidly induce EROD and are slightly more sensitive than cultured hepatocytes, and could be used as a rapid and sensitive tool for screening chemicals and monitoring environmental AhR agonist toxicants. PMID:16959333

  1. DETECTION OF HUMAN LUNG EPITHELIA CELL GROWTH FACTORS PRODUCED BY A LUNG CARCINOMA CELL LINE: USE IN CULTURE OF PRIMARY SOLID LUNG TUMORS

    EPA Science Inventory

    Serum-free medium conditioned for 72 h by a human undifferentiated adenocarcinoma of lung, Cal u 6, stimulated the colony formation of normal human bronchial epithelial cells, newly cultured cells from human solid lung tumors, and established human lung tumor cell lines, includin...

  2. Xenogeneic lung transplantation models

    PubMed Central

    Burdorf, Lars; Azimzadeh, Agnes M.; Pierson, Richard N.

    2014-01-01

    Summary Study of lung xenografts has proven useful to understand the remaining barriers to successful transplantation of other organ xenografts. In this chapter, the history and current status of lung xenotransplantation will be briefly reviewed and two different experimental models, the ex vivo porcine-to-human lung perfusion and the in vivo xenogeneic lung transplantation, will be presented. We will focus on the technical details of these lung xenograft models in sufficient detail, list the needed materials and mention analysis techniques to allow others to adopt them with minimal learning curve. PMID:22565996

  3. Dengue viruses can infect human primary lung epithelia as well as lung carcinoma cells, and can also induce the secretion of IL-6 and RANTES.

    PubMed

    Lee, Ying-Ray; Su, Ching-Yao; Chow, Nan-Haw; Lai, Wu-Wei; Lei, Huan-Yao; Chang, Chia-Lun; Chang, Tsuey-Yu; Chen, Shun-Hua; Lin, Yee-Shin; Yeh, Trai-Ming; Liu, Hsiao-Sheng

    2007-06-01

    Dengue viruses (DENV) are herein demonstrated for the first time as being able to infect and replicate in human primary lung epithelium and various lung cancer cell lines. The detection of dengue virus particles and viral negative strand RNA synthesis in the cell, in conjunction with the release of viral progenies in culture supernatants, support the notion that lung cells are susceptible to dengue virus infection. The replication efficiency of DENV in lung cancer cells from high to low is: DEN-2 (dengue virus type-2), DEN-3, DEN-4 and DEN-1. Moreover, the susceptibility of the six lung cancer cell lines to DEN-2 infection is: SW1573>A549>H1435; H23; H520; Bes2B. DEN-2 infection significantly increased the expression levels of IL-6 and RANTES in four of the six lung cancer cell lines, which is consistent with the high expression levels of these molecules in DHF/DSS patients. IL-6 expression induced by DEN-2 infection was NF-kappaB dependent. In summary, our results indicate that lung epithelial cell is a possible target of dengue viruses and IL-6 and RANTES may play pivotal roles in lung related immuno-pathogenesis. PMID:17416433

  4. Adenovirus-mediated gene transfer to ciliated airway epithelia requires prolonged incubation time.

    PubMed Central

    Zabner, J; Zeiher, B G; Friedman, E; Welsh, M J

    1996-01-01

    The efficiency of adenovirus-mediated gene transfer to airway epithelia will be an important factor in determining whether recombinant adenoviruses can be developed as vectors for transferring cystic fibrosis transmembrane conductance regulator (CFTR) cDNA to patients with cystic fibrosis. Current understanding of the biology of CF lung disease suggests that vectors should express transgene in mature, ciliated airway epithelia. We evaluated the efficiency of adenovirus-mediated gene transfer to primary cultures of normal and CF human airway epithelia. Our studies showed that the airway cells developed from an undifferentiated epithelium with markers characteristic of basal cells and a surface covered by short microvilli 3 days after seeding to a mature epithelium whose apical surface was covered with cilia by 10 to 14 days. The ability of adenovirus vectors to express a reporter gene and to correct defective cyclic AMP-stimulated Cl- transport in CF epithelia was correlated inversely with the state of differentiation. However, the inefficiency of adenovirus-mediated gene transfer could be partially corrected when the contact time between vector and epithelium was prolonged. After prolonged contact, we observed complete correction of the CF Cl- transport defect in differentiated CF airway epithelia in culture and of the Cl- transport defect in the nasal epithelia of mice homozygous for the deltaF508 mutation. The fact that gene transfer to airway epithelia required prolonged incubation with vector contrasts with the rapid infection observed in cell models such as 293 and HeLa cells, which are commonly used to study adenovirus infection. Gene transfer observed after prolonged incubation may result from mechanisms different from those that mediate infection of 293 cells. These observations suggest that interventions that either increase the contact time or alter the epithelium or the vector may be required to facilitate gene transfer to ciliated respiratory epithelia

  5. CFTR is required for maximal transepithelial liquid transport in pig alveolar epithelia.

    PubMed

    Li, Xiaopeng; Comellas, Alejandro P; Karp, Philip H; Ernst, Sarah E; Moninger, Thomas O; Gansemer, Nicholas D; Taft, Peter J; Pezzulo, Alejandro A; Rector, Michael V; Rossen, Nathan; Stoltz, David A; McCray, Paul B; Welsh, Michael J; Zabner, Joseph

    2012-07-01

    A balance between alveolar liquid absorption and secretion is critical for maintaining optimal alveolar subphase liquid height and facilitating gas exchange in the alveolar space. However, the role of cystic fibrosis transmembrane regulator protein (CFTR) in this homeostatic process has remained elusive. Using a newly developed porcine model of cystic fibrosis, in which CFTR is absent, we investigated ion transport properties and alveolar liquid transport in isolated type II alveolar epithelial cells (T2AECs) cultured at the air-liquid interface. CFTR was distributed exclusively to the apical surface of cultured T2AECs. Alveolar epithelia from CFTR(-/-) pigs failed to increase liquid absorption in response to agents that increase cAMP, whereas cAMP-stimulated liquid absorption in CFTR(+/-) epithelia was similar to that in CFTR(+/+) epithelia. Expression of recombinant CFTR restored stimulated liquid absorption in CFTR(-/-) T2AECs but had no effect on CFTR(+/+) epithelia. In ex vivo studies of nonperfused lungs, stimulated liquid absorption was defective in CFTR(-/-) alveolar epithelia but similar between CFTR(+/+) and CFTR(+/-) epithelia. When epithelia were studied at the air-liquid interface, elevating cAMP levels increased subphase liquid height in CFTR(+/+) but not in CFTR(-/-) T2AECs. Our findings demonstrate that CFTR is required for maximal liquid absorption under cAMP stimulation, but it is not the rate-limiting factor. Furthermore, our data define a role for CFTR in liquid secretion by T2AECs. These insights may help to develop new treatment strategies for pulmonary edema and respiratory distress syndrome, diseases in which lung liquid transport is disrupted. PMID:22637155

  6. CFTR is required for maximal transepithelial liquid transport in pig alveolar epithelia

    PubMed Central

    Li, Xiaopeng; Comellas, Alejandro P.; Karp, Philip H.; Ernst, Sarah E.; Moninger, Thomas O.; Gansemer, Nicholas D.; Taft, Peter J.; Pezzulo, Alejandro A.; Rector, Michael V.; Rossen, Nathan; Stoltz, David A.; McCray, Paul B.; Welsh, Michael J.

    2012-01-01

    A balance between alveolar liquid absorption and secretion is critical for maintaining optimal alveolar subphase liquid height and facilitating gas exchange in the alveolar space. However, the role of cystic fibrosis transmembrane regulator protein (CFTR) in this homeostatic process has remained elusive. Using a newly developed porcine model of cystic fibrosis, in which CFTR is absent, we investigated ion transport properties and alveolar liquid transport in isolated type II alveolar epithelial cells (T2AECs) cultured at the air-liquid interface. CFTR was distributed exclusively to the apical surface of cultured T2AECs. Alveolar epithelia from CFTR−/− pigs failed to increase liquid absorption in response to agents that increase cAMP, whereas cAMP-stimulated liquid absorption in CFTR+/− epithelia was similar to that in CFTR+/+ epithelia. Expression of recombinant CFTR restored stimulated liquid absorption in CFTR−/− T2AECs but had no effect on CFTR+/+ epithelia. In ex vivo studies of nonperfused lungs, stimulated liquid absorption was defective in CFTR−/− alveolar epithelia but similar between CFTR+/+ and CFTR+/− epithelia. When epithelia were studied at the air-liquid interface, elevating cAMP levels increased subphase liquid height in CFTR+/+ but not in CFTR−/− T2AECs. Our findings demonstrate that CFTR is required for maximal liquid absorption under cAMP stimulation, but it is not the rate-limiting factor. Furthermore, our data define a role for CFTR in liquid secretion by T2AECs. These insights may help to develop new treatment strategies for pulmonary edema and respiratory distress syndrome, diseases in which lung liquid transport is disrupted. PMID:22637155

  7. Mathematical model of nucleotide regulation on airway epithelia. Implications for airway homeostasis.

    PubMed

    Zuo, Peiying; Picher, Maryse; Okada, Seiko F; Lazarowski, Eduardo R; Button, Brian; Boucher, Richard C; Elston, Timothy C

    2008-09-26

    In the airways, adenine nucleotides support a complex signaling network mediating host defenses. Released by the epithelium into the airway surface liquid (ASL) layer, they regulate mucus clearance through P2 (ATP) receptors, and following surface metabolism through P1 (adenosine; Ado) receptors. The complexity of ASL nucleotide regulation provides an ideal subject for biochemical network modeling. A mathematical model was developed to integrate nucleotide release, the ectoenzymes supporting the dephosphorylation of ATP into Ado, Ado deamination into inosine (Ino), and nucleoside uptake. The model also includes ecto-adenylate kinase activity and feed-forward inhibition of Ado production by ATP and ADP. The parameters were optimized by fitting the model to experimental data for the steady-state and transient concentration profiles generated by adding ATP to polarized primary cultures of human bronchial epithelial (HBE) cells. The model captures major aspects of ATP and Ado regulation, including their >4-fold increase in concentration induced by mechanical stress mimicking normal breathing. The model also confirmed the independence of steady-state nucleotide concentrations on the ASL volume, an important regulator of airway clearance. An interactive approach between simulations and assays revealed that feed-forward inhibition is mediated by selective inhibition of ecto-5'-nucleotidase. Importantly, the model identifies ecto-adenylate kinase as a key regulator of ASL ATP and proposes novel strategies for the treatment of airway diseases characterized by impaired nucleotide-mediated clearance. These new insights into the biochemical processes supporting ASL nucleotide regulation illustrate the potential of this mathematical model for fundamental and clinical research. PMID:18662982

  8. Improved development of somatic cell cloned bovine embryos by a mammary gland epithelia cells in vitro model.

    PubMed

    He, Xiao-Ying; Ma, Li-Bing; He, Xiao-Ning; Si, Wan-Tong; Zheng, Yue-Mao

    2016-06-30

    Previous studies have established a bovine mammary gland epithelia cells in vitro model by the adenovirus-mediated telomerase (hTERT-bMGEs). The present study was conducted to confirm whether hTERT-bMGEs were effective target cells to improve the efficiency of transgenic expression and somatic cell nuclear transfer (SCNT). To accomplish this, a mammary-specific vector encoding human lysozyme and green fluorescent protein was used to verify the transgenic efficiency of hTERT-bMGEs, and untreated bovine mammary gland epithelial cells (bMGEs) were used as a control group. The results showed that the hTERT-bMGEs group had much higher transgenic efficiency and protein expression than the bMGEs group. Furthermore, the nontransgenic and transgenic hTERT-bMGEs were used as donor cells to evaluate the efficiency of SCNT. There were no significant differences in rates of cleavage or blastocysts or hatched blastocysts of cloned embryos from nontransgenic hTERT-bMGEs at passage 18 and 28 groups (82.8% vs. 81.9%, 28.6% vs. 24.8%, 58.6% vs. 55.3%, respectively) and the transgenic group (80.8%, 26.5% and 53.4%); however, they were significantly higher than the bMGEs group (71.2%, 12.8% and 14.8%), (p < 0.05). We confirmed that hTERT-bMGEs could serve as effective target cells for improving development of somatic cell cloned cattle embryos. PMID:26243608

  9. Improved development of somatic cell cloned bovine embryos by a mammary gland epithelia cells in vitro model

    PubMed Central

    Ma, Li-bing; He, Xiao-ning; Si, Wan-tong; Zheng, Yue-Mao

    2016-01-01

    Previous studies have established a bovine mammary gland epithelia cells in vitro model by the adenovirus-mediated telomerase (hTERT-bMGEs). The present study was conducted to confirm whether hTERT-bMGEs were effective target cells to improve the efficiency of transgenic expression and somatic cell nuclear transfer (SCNT). To accomplish this, a mammary-specific vector encoding human lysozyme and green fluorescent protein was used to verify the transgenic efficiency of hTERT-bMGEs, and untreated bovine mammary gland epithelial cells (bMGEs) were used as a control group. The results showed that the hTERT-bMGEs group had much higher transgenic efficiency and protein expression than the bMGEs group. Furthermore, the nontransgenic and transgenic hTERT-bMGEs were used as donor cells to evaluate the efficiency of SCNT. There were no significant differences in rates of cleavage or blastocysts or hatched blastocysts of cloned embryos from nontransgenic hTERT-bMGEs at passage 18 and 28 groups (82.8% vs. 81.9%, 28.6% vs. 24.8%, 58.6% vs. 55.3%, respectively) and the transgenic group (80.8%, 26.5% and 53.4%); however, they were significantly higher than the bMGEs group (71.2%, 12.8% and 14.8%), (p < 0.05). We confirmed that hTERT-bMGEs could serve as effective target cells for improving development of somatic cell cloned cattle embryos. PMID:26243608

  10. Exposure to Engineered Nanomaterial Results in Disruption of Brush Borders in Epithelia Models in vitro

    NASA Astrophysics Data System (ADS)

    Faust, James J.

    Engineered nanoparticles (NP; 10-9 m) have found use in a variety of consumer goods and medical devices because of the unique changes in material properties that occur when synthesized on the nanoscale. Although many definitions for nanoparticle exist, from the perspective of size, nanoparticle is defined as particles with diameters less than 100 nm in any external dimension. Examples of their use include titanium dioxide added as a pigment in products intended to be ingested by humans, silicon dioxide NPs are used in foods as an anticaking agent, and gold or iron oxide NPs can be used as vectors for drug delivery or contrast agents for specialized medical imaging. Although the intended use of these NPs is often to improve human health, it has come to the attention of investigators that NPs can have unintended or even detrimental effects on the organism. This work describes one such unintended effect of NP exposure from the perspective of exposure via the oral route. First, this Dissertation will explain an event referred to as brush border disruption that occurred after nanoparticles interacted with an in vitro model of the human intestinal epithelium. Second, this Dissertation will identify and characterize several consumer goods that were shown to contain titanium dioxide that are intended to be ingested. Third, this Dissertation shows that sedimentation due to gravity does not artifactually result in disruption of brush borders as a consequence of exposure to food grade titanium dioxide in vitro. Finally, this Dissertation will demonstrate that iron oxide nanoparticles elicited similar effects after exposure to an in vitro brush border expressing model of the human placenta. Together, these data suggest that brush border disruption is not an artifact of the material/cell culture model, but instead represents a bona fide biological response as a result of exposure to nanomaterial.

  11. Basolateral Mg2+ Extrusion via CNNM4 Mediates Transcellular Mg2+ Transport across Epithelia: A Mouse Model

    PubMed Central

    Miura, Jiro; Sato, Sunao; Toyosawa, Satoru; Furutani, Kazuharu; Kurachi, Yoshihisa; Omori, Yoshihiro; Furukawa, Takahisa; Tsuda, Tetsuya; Kuwabata, Susumu; Mizukami, Shin; Kikuchi, Kazuya; Miki, Hiroaki

    2013-01-01

    Transcellular Mg2+ transport across epithelia, involving both apical entry and basolateral extrusion, is essential for magnesium homeostasis, but molecules involved in basolateral extrusion have not yet been identified. Here, we show that CNNM4 is the basolaterally located Mg2+ extrusion molecule. CNNM4 is strongly expressed in intestinal epithelia and localizes to their basolateral membrane. CNNM4-knockout mice showed hypomagnesemia due to the intestinal malabsorption of magnesium, suggesting its role in Mg2+ extrusion to the inner parts of body. Imaging analyses revealed that CNNM4 can extrude Mg2+ by exchanging intracellular Mg2+ with extracellular Na+. Furthermore, CNNM4 mutations cause Jalili syndrome, characterized by recessive amelogenesis imperfecta with cone-rod dystrophy. CNNM4-knockout mice showed defective amelogenesis, and CNNM4 again localizes to the basolateral membrane of ameloblasts, the enamel-forming epithelial cells. Missense point mutations associated with the disease abolish the Mg2+ extrusion activity. These results demonstrate the crucial importance of Mg2+ extrusion by CNNM4 in organismal and topical regulation of magnesium. PMID:24339795

  12. Human airway epithelia express catalytically active NEU3 sialidase

    PubMed Central

    Hyun, Sang Won; Feng, Chiguang; Zhang, Lei; Liu, Anguo; Guang, Wei; Nguyen, Chinh; Sun, Wenji; Luzina, Irina G.; Webb, Tonya J.; Atamas, Sergei P.; Passaniti, Antonino; Twaddell, William S.; Puché, Adam C.; Wang, Lai-Xi; Cross, Alan S.; Goldblum, Simeon E.

    2014-01-01

    Sialic acids on glycoconjugates play a pivotal role in many biological processes. In the airways, sialylated glycoproteins and glycolipids are strategically positioned on the plasma membranes of epithelia to regulate receptor-ligand, cell-cell, and host-pathogen interactions at the molecular level. We now demonstrate, for the first time, sialidase activity for ganglioside substrates in human airway epithelia. Of the four known mammalian sialidases, NEU3 has a substrate preference for gangliosides and is expressed at mRNA and protein levels at comparable abundance in epithelia derived from human trachea, bronchi, small airways, and alveoli. In small airway and alveolar epithelia, NEU3 protein was immunolocalized to the plasma membrane, cytosolic, and nuclear subcellular fractions. Small interfering RNA-induced silencing of NEU3 expression diminished sialidase activity for a ganglioside substrate by >70%. NEU3 immunostaining of intact human lung tissue could be localized to the superficial epithelia, including the ciliated brush border, as well as to nuclei. However, NEU3 was reduced in subepithelial tissues. These results indicate that human airway epithelia express catalytically active NEU3 sialidase. PMID:24658138

  13. Lung Cancer Risk Prediction Models

    Cancer.gov

    Developing statistical models that estimate the probability of developing lung cancer over a defined period of time will help clinicians identify individuals at higher risk of specific cancers, allowing for earlier or more frequent screening and counseling of behavioral changes to decrease risk.

  14. Isotonic water transport in secretory epithelia.

    PubMed

    Swanson, C H

    1977-01-01

    The model proposed by Diamond and Bossert [1] for isotonic water transport has received wide acceptance in recent years. It assumes that the local driving force for water transport is a standing osmotic gradient produced in the lateral intercellular spaces of the epithelial cell layer by active solute transport. While this model is based on work done in absorptive epithelia where the closed to open direction of the lateral space and the direction of net transport are the same, it has been proposed that the lateral spaces could also serve as the site of the local osmotic gradients for water transport in secretory epithelia, where the closed to open direction of the lateral space and net transport are opposed, by actively transporting solute out of the space rather than into it. Operation in the backward direction, however, requires a lower than ambient hydrostatic pressure within the lateral space which would seem more likely to cause the space to collapse with loss of function. On the other hand, most secretory epithelia are characterized by transport into a restricted ductal system which is similar to the lateral intercellular space in the absorptive epithelia in that its closed to open direction is the same as that of net transport. In vitro micropuncture studies on the exocrine pancreas of the rabbit indicate the presence of a small but statistically significant increase in juice osmolality, 6 mOsm/kg H(2)O, at the site of electrolyte and water secretion in the smallest extralobular ducts with secretin stimulation which suggests that the ductal system in the secretory epithelia rather than the lateral intercellular space is the site of the local osmotic gradients responsible for isotonic water transport. PMID:331693

  15. Mouse models for lung cancer.

    PubMed

    Kwon, Min-chul; Berns, Anton

    2013-04-01

    Lung cancer is a devastating disease and a major therapeutic burden with poor survival rates. It is responsible for 30% of all cancer deaths. Lung cancer is strongly associated with smoking, although some subtypes are also seen in non-smokers. Tumors in the latter group are mostly adenocarcinomas with many carrying mutations in the epidermal growth factor receptor (EGFR). Survival statistics of lung cancer are grim because of its late detection and frequent local and distal metastases. Although DNA sequence information from tumors has revealed a number of frequently occurring mutations, affecting well-known tumor suppressor genes and proto-oncogenes, many of the driver mutations remain ill defined. This is likely due to the involvement of numerous rather infrequently occurring driver mutations that are difficult to distinguish from the very large number of passenger mutations detected in smoking-related lung cancers. Therefore, experimental model systems are indispensable to validate putative driver lesions and to gain insight into their mechanisms of action. Whereas a large fraction of these analyzes can be performed in cell cultures in vitro, in many cases the consequences of the mutations have to be assessed in the context of an intact organism, as this is the context in which the Mendelian selection process of the tumorigenic process took place and the advantages of particular mutations become apparent. Current mouse models for cancer are very suitable for this as they permit mimicking many of the salient features of human tumors. The capacity to swiftly re-engineer complex sets of lesions found in human tumors in mice enables us to assess the contribution of defined combinations of lesions to distinct tumor characteristics such as metastatic behavior and response to therapy. In this review we will describe mouse models of lung cancer and how they are used to better understand the disease and how they are exploited to develop better intervention strategies

  16. Clostridium difficile-mediated effects on human intestinal epithelia: Modelling host-pathogen interactions in a vertical diffusion chamber.

    PubMed

    Jafari, Nazila V; Kuehne, Sarah A; Minton, Nigel P; Allan, Elaine; Bajaj-Elliott, Mona

    2016-02-01

    Clostridium difficile infection is one of the leading causes of healthcare associated diarrhoea in the developed world. Although the contribution of C. difficile toxins to disease pathogenesis is now well understood, many facets of host-pathogen interactions between the human intestinal epithelia and the C. difficile bacterium that may contribute to asymptomatic carriage and/or clinical disease remain less clear. Herein, we tested the hypothesis that C. difficile strains mediate intestinal epithelial cell (IEC) antimicrobial immunity via toxin dependent and independent means and that the 'anaerobic' environment has a significant impact on bacterial-IEC interactions. Crosstalk between three C. difficile PCR ribotypes (RT) [RT027 (strain R20291), RT012 (strain 630) and RT017 (strains M68 and CF5)] and IEC cell-lines were investigated. All RTs showed significant engagement with human Toll-like receptors (TLR)-5, TLR2-CD14 and TLR2/6 as measured by IL-8 release from TLR-transfected HEK cells. Co-culture studies indicated minimal impact of R20291 and 630 TcdA and TcdB on bacterial adherence to Caco-2 cells. An apical anaerobic environment had a major effect on C. difficile-T84 crosstalk as significantly greater cytokine immunity and trans-epithelial electrical resistance (TEER) dysfunction was recorded when co-cultures were performed in an Ussing chamber system compared to standard 5% CO2 conditions. Overall, this study suggests that anaerobic C. difficile engagement with human IECs is a complex interplay that involves bacterial and toxin-mediated cellular events. PMID:26708704

  17. Lung models: strengths and limitations.

    PubMed

    Martonen, T B; Musante, C J; Segal, R A; Schroeter, J D; Hwang, D; Dolovich, M A; Burton, R; Spencer, R M; Fleming, J S

    2000-06-01

    The most widely used particle dosimetry models are those proposed by the National Council on Radiation Protection, International Commission for Radiological Protection, and the Netherlands National Institute of Public Health and the Environment (the RIVM model). Those models have inherent problems that may be regarded as serious drawbacks: for example, they are not physiologically realistic. They ignore the presence and commensurate effects of naturally occurring structural elements of lungs (eg, cartilaginous rings, carinal ridges), which have been demonstrated to affect the motion of inhaled air. Most importantly, the surface structures have been shown to influence the trajectories of inhaled particles transported by air streams. Thus, the model presented herein by Martonen et al may be perhaps the most appropriate for human lung dosimetry. In its present form, the model's major "strengths" are that it could be used for diverse purposes in medical research and practice, including: to target the delivery of drugs for diseases of the respiratory tract (eg, cystic fibrosis, asthma, bronchogenic carcinoma); to selectively deposit drugs for systemic distribution (eg, insulin); to design clinical studies; to interpret scintigraphy data from human subject exposures; to determine laboratory conditions for animal testing (ie, extrapolation modeling); and to aid in aerosolized drug delivery to children (pediatric medicine). Based on our research, we have found very good agreement between the predictions of our model and the experimental data of Heyder et al, and therefore advocate its use in the clinical arena. In closing, we would note that for the simulations reported herein the data entered into our computer program were the actual conditions of the Heyder et al experiments. However, the deposition model is more versatile and can simulate many aerosol therapy scenarios. For example, the core model has many computer subroutines that can be enlisted to simulate the

  18. Luminal acetylcholine does not affect the activity of the CFTR in tracheal epithelia of pigs.

    PubMed

    Dittrich, Nikolaus P; Kummer, Wolfgang; Clauss, Wolfgang G; Fronius, Martin

    2015-11-01

    Fluid homeostasis mediated by the airway epithelium is required for proper lung function, and the CFTR (cystic fibrosis transmembrane conductance regulator) Cl(-) channel is crucial for these processes. Luminal acetylcholine (ACh) acts as an auto-/paracrine mediator to activate Cl(-) channels in airway epithelia and evidence exists showing that nicotinic ACh receptors activate CFTR in murine airway epithelia. The present study investigated whether or not luminal ACh regulates CFTR activity in airway epithelia of pigs, an emerging model for investigations of human airway disease and cystic fibrosis (CF) in particular. Transepithelial ion currents of freshly dissected pig tracheal preparations were measured with Ussing chambers. Application of luminal ACh (100 μM) induced an increase of the short-circuit current (I(SC)). The ACh effect was mimicked by muscarine and pilocarpine (100 μM each) and was sensitive to muscarinic receptor antagonists (atropine, 4-DAMP, pirenzepine). No changes of the I(SC) were observed by nicotine (100 μM) and ACh responses were not affected by nicotine or mecamylamine (25 μM). Luminal application of IBMX (I, 100 μM) and forskolin (F, 10 μM), increase the I(SC) and the I/F-induced current were decreased by the CFTR inhibitor GlyH-101 (GlyH, 50 μM) indicating increased CFTR activity by I/F. In contrast, GlyH did not affect the ACh-induced current, indicating that the ACh response does not involve the activation of the CFTR. Results from this study suggest that luminal ACh does not regulate the activity of the CFTR in tracheal epithelia of pigs which opposes observation from studies using mice airway epithelium. PMID:26286842

  19. Cultured lung epithelium: A cellular model for lung preservation.

    PubMed

    Lee, C Y; Matsumoto-Pon, J; Widdicombe, J H

    1997-11-01

    Cellular models have helped with the development of conditions needed for hypothermic preservation of kidney, liver, and heart. Recently, highly differentiated cultured lung epithelial cell lines grown with basolateral side feeding technique have become available that can mimic airspace, epithelium, and interstitium of lung parenchyma. Cultured lung epithelium coupled with Ussing's short-circuit current technique was used as a cellular model system for lung preservation. A parametric study was conducted to correlate the effects of luminal fluid composition (University of Wisconsin (UW) solution and phosphate-buffered saline) and storage gas (air vs nitrogen) at 4 degrees C for 24 h on postischemic electrogenic properties (transepithelial ion transport and resistance). The results showed that cells were better preserved with the UW solution on both sides as measured by their transepithelial resistance, an indicator of tight junction integrity (Rte approximately 65% of control values approximately 135 Omega cm2). In addition, they responded better to mediators that stimulate chloride secretion than cells preserved with other conditions. Cells preserved with no additional fluid on the apical side had substantially lowered Rte (<20%) than those preserved with an additional thin layer of fluid ( approximately 35-65%). This cellular model system is a realistic representation of lung epithelium and can provide an accurate assessment of preservation quality through the measurements of tight junction integrity and active ion transport. PMID:9367609

  20. Animal models of acute lung injury

    PubMed Central

    Matute-Bello, Gustavo; Frevert, Charles W.; Martin, Thomas R.

    2008-01-01

    Acute lung injury in humans is characterized histopathologically by neutrophilic alveolitis, injury of the alveolar epithelium and endothelium, hyaline membrane formation, and microvascular thrombi. Different animal models of experimental lung injury have been used to investigate mechanisms of lung injury. Most are based on reproducing in animals known risk factors for ARDS, such as sepsis, lipid embolism secondary to bone fracture, acid aspiration, ischemia-reperfusion of pulmonary or distal vascular beds, and other clinical risks. However, none of these models fully reproduces the features of human lung injury. The goal of this review is to summarize the strengths and weaknesses of existing models of lung injury. We review the specific features of human ARDS that should be modeled in experimental lung injury and then discuss specific characteristics of animal species that may affect the pulmonary host response to noxious stimuli. We emphasize those models of lung injury that are based on reproducing risk factors for human ARDS in animals and discuss the advantages and disadvantages of each model and the extent to which each model reproduces human ARDS. The present review will help guide investigators in the design and interpretation of animal studies of acute lung injury. PMID:18621912

  1. Mechanics and Patterning in Metazoan Epithelia

    NASA Astrophysics Data System (ADS)

    Chiou, Kevin K.

    In this dissertation we consider the effect of mechanical interactions on cell biology and how this translates into tissue-level properties in metazoan epithelia. We delineate three model-based approaches with different phenomenological aims and compare applicable results to experimental data. We first consider cellular vertex model simulations, which are used to represent the mechanics of two-dimensional epithelial cell arrays. We outline the assumptions, parameters, and outputs. Then we review a number of systems in which these simulations have been used. The second approach is the Mechanical Inverse, which is a vertex model-based approach to inferring mechanical stresses from cell boundary labeled images of epithelial tissue. We develop this inference method from the assumption of mechanical equilibrium and dominant stresses in the tissue. We then apply this computational method to experimental images and validate the performance. In the final part we consider avian cochlea development in epithelia where lateral inhibition plays a role in cell differentiation—a process which involves cell division, differentiation, and rearrangement in a two-dimensional epithelial layer. We develop a mean-field mathematical description of this process. The results provide a description of the observed hair cell patterns in the cochlea.

  2. Computational fluid dynamics modeling of airflow inside lungs using heterogenous anisotropic lung tissue elastic properties.

    PubMed

    Ilegbusi, Olusegun; Li, Ziang; Min, Yugang; Meeks, Sanford; Kupelian, Patrick; Santhanam, Anand P

    2012-01-01

    The aim of this paper is to model the airflow inside lungs during breathing and its fluid-structure interaction with the lung tissues and the lung tumor using subject-specific elastic properties. The fluid-structure interaction technique simultaneously simulates flow within the airway and anisotropic deformation of the lung lobes. The three-dimensional (3D) lung geometry is reconstructed from the end-expiration 3D CT scan datasets of humans with lung cancer. The lung is modeled as a poro-elastic medium with anisotropic elastic property (non-linear Young's modulus) obtained from inverse lung elastography of 4D CT scans for the same patients. The predicted results include the 3D anisotropic lung deformation along with the airflow pattern inside the lungs. The effect is also presented of anisotropic elasticity on both the spatio-temporal volumetric lung displacement and the regional lung hysteresis. PMID:22356987

  3. Animal model for anaerobic lung abscess.

    PubMed Central

    Kannangara, D W; Thadepalli, H; Bach, V T; Webb, D

    1981-01-01

    There are no satisfactory animal models for the study of anaerobic lung abscess. Aspiration of food, gastric mucin, or hydrochloric acid, or any combination of these, along with oropharyngeal bacteria, is commonly believed to cause aspiration pneumonia and lung abscess. In the animal model described, none of the adjuvants was effective in producing anaerobic lung abscesses. Anaerobic bacteria derived from dental scrapings of a healthy adult (Peptococcus morbillorum, Fusobacterium nucleatum, Eubacterium lentum, and Bacteroides fragilis), when inoculated transtracheally without any adjuvants into New Zealand male white rabbits, consistently produced lung abscesses. Neither B fragilis by itself nor a mixture of P. morbillorum, F. nucleatum, and E. lentum without the addition of B. fragilis produced lung abscesses. The bacterial isolates used in this study were stored in prereduced chopped-meat-glucose medium and subcultured several times and were found effective in reproducing anaerobic lung abscesses repeatedly. This animal model is suitable for the study of pathogenesis, diagnosis, and treatment of B. fragilis-associated anaerobic lung abscess. Images PMID:7216463

  4. Particle Image Velocimetry in Lung Bifurcation Models

    NASA Astrophysics Data System (ADS)

    Theunissen, Raf; Riethmuller, Michel L.

    To better understand the human pulmonary system and governing aerosol deposition mechanisms within the lung, an accurate description of the airflow in the conductive and respiratory pulmonary airways is considered to be essential. In-vivo measurements are deemed impossible due to the small scales in the lung structure. Though numerical simulations can improve the insight, validation of the results is mostly lacking, especially in the extraction of particle trajectories. Numerical and experimental studies have been performed at the von Karman Institute for Fluid Dynamics on single and multiple bifurcation models representing simplifications of the lung system. Both steady and oscillating flows have been studied for the upper lung airways, while steady flow conditions were imposed in the modeling of the alveolar zones. Further experiments consisted in the extraction of particle trajectories in the models of the respiratory airways. This chapter presents an overview of the conducted measurement campaigns complemented with the main observations and results.

  5. A free-breathing lung motion model

    NASA Astrophysics Data System (ADS)

    Zhao, Tianyu

    Lung cancer has been the leading cause of cancer deaths for decades in the United States. Although radiotherapy is one of the most effective treatments, side effects from error in delivery of radiation due to organ motion during breathing remain a significant issue. To compensate the breathing motion during the treatment, a free breathing lung motion model, x= x0+αv+betaf, was developed and discussed, where x is the position of a piece of tissue located at reference position x0. α is a parameter which characterizes the motion due to local air filling (motion as a function of tidal volume) and beta is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation which cause lung motion hysteresis (motion as a function of airflow). The parameters α and beta together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The theoretical foundation of the model was built by investigating the stress distribution inside of a lung and the biomechanical properties of the lung tissues. Accuracy of the model was investigated by using 49 free-breathing patient data sets. Applications of the model in localizing lung cancer, monitoring radiation damage and suppressing artifacts in free-breathing PET images were also discussed. This work supported in part by NIHR01CA096679 and NIHR01CA116712.

  6. Production of β-defensins by human airway epithelia

    PubMed Central

    Singh, Pradeep K.; Jia, Hong Peng; Wiles, Kerry; Hesselberth, Jay; Liu, Lide; Conway, Barbara-Ann D.; Greenberg, Everett P.; Valore, Erika V.; Welsh, Michael J.; Ganz, Tomas; Tack, Brian F.; McCray, Paul B.

    1998-01-01

    Human β-defensins (HBDs) are antimicrobial peptides that may play a role in mucosal defense. Diminished activity of these peptides has been implicated in the pathogenesis of cystic fibrosis (CF) lung disease. We show that HBD-1 and HBD-2 mRNAs are expressed in excised surface and submucosal gland epithelia from non-CF and CF patients. The pro-inflammatory cytokine interleukin-1β stimulated the expression of HBD-2 but not HBD-1 mRNA and peptide in primary cultures of airway epithelia. HBD-1 was found in bronchoalveolar lavage (BAL) fluid from normal volunteers, CF patients, and patients with inflammatory lung diseases, whereas HBD-2 was detected in BAL fluid from patients with CF or inflammatory lung diseases, but not in normal volunteers. Both HBD-1 and HBD-2 were found in BAL fluid in concentrations of several ng/ml, and both recombinant peptides showed salt-sensitive bactericidal activity. These data suggest that in the lung HBD-2 expression is induced by inflammation, whereas HBD-1 may serve as a defense in the absence of inflammation. PMID:9843998

  7. CISNET lung models: Comparison of model assumptions and model structures

    PubMed Central

    McMahon, Pamela M.; Hazelton, William; Kimmel, Marek; Clarke, Lauren

    2012-01-01

    Sophisticated modeling techniques can be powerful tools to help us understand the effects of cancer control interventions on population trends in cancer incidence and mortality. Readers of journal articles are however rarely supplied with modeling details. Six modeling groups collaborated as part of the National Cancer Institute’s Cancer Intervention and Surveillance Modeling Network (CISNET) to investigate the contribution of US tobacco control efforts towards reducing lung cancer deaths over the period 1975 to 2000. The models included in this monograph were developed independently and use distinct, complementary approaches towards modeling the natural history of lung cancer. The models used the same data for inputs and agreed on the design of the analysis and the outcome measures. This article highlights aspects of the models that are most relevant to similarities of or differences between the results. Structured comparisons can increase the transparency of these complex models. PMID:22882887

  8. Comparison of lung preservation solutions in human lungs using an ex vivo lung perfusion experimental model

    PubMed Central

    Medeiros, Israel L.; Pêgo-Fernandes, Paulo M.; Mariani, Alessandro W.; Fernandes, Flávio G.; Unterpertinger, Fernando V.; Canzian, Mauro; Jatene, Fabio B.

    2012-01-01

    OBJECTIVE: Experimental studies on lung preservation have always been performed using animal models. We present ex vivo lung perfusion as a new model for the study of lung preservation. Using human lungs instead of animal models may bring the results of experimental studies closer to what could be expected in clinical practice. METHOD: Brain-dead donors whose lungs had been declined by transplantation teams were used. The cases were randomized into two groups. In Group 1, Perfadex® was used for pulmonary preservation, and in Group 2, LPDnac, a solution manufactured in Brazil, was used. An ex vivo lung perfusion system was used, and the lungs were ventilated and perfused after 10 hours of cold ischemia. The extent of ischemic-reperfusion injury was measured using functional and histological parameters. RESULTS: After reperfusion, the mean oxygenation capacity was 405.3 mmHg in Group 1 and 406.0 mmHg in Group 2 (p = 0.98). The mean pulmonary vascular resistance values were 697.6 and 378.3 dyn·s·cm-5, respectively (p = 0.035). The mean pulmonary compliance was 46.8 cm H2O in Group 1 and 49.3 ml/cm H2O in Group 2 (p = 0.816). The mean wet/dry weight ratios were 2.06 and 2.02, respectively (p = 0.87). The mean Lung Injury Scores for the biopsy performed after reperfusion were 4.37 and 4.37 in Groups 1 and 2, respectively (p = 1.0), and the apoptotic cell counts were 118.75/mm2 and 137.50/mm2, respectively (p = 0.71). CONCLUSION: The locally produced preservation solution proved to be as good as Perfadex®. The clinical use of LPDnac may reduce costs in our centers. Therefore, it is important to develop new models to study lung preservation. PMID:23018310

  9. Targeted Type 2 Alveolar Cell Depletion. A Dynamic Functional Model for Lung Injury Repair.

    PubMed

    Garcia, Orquidea; Hiatt, Michael J; Lundin, Amber; Lee, Jooeun; Reddy, Raghava; Navarro, Sonia; Kikuchi, Alex; Driscoll, Barbara

    2016-03-01

    Type 2 alveolar epithelial cells (AEC2) are regarded as the progenitor population of the alveolus responsible for injury repair and homeostatic maintenance. Depletion of this population is hypothesized to underlie various lung pathologies. Current models of lung injury rely on either uncontrolled, nonspecific destruction of alveolar epithelia or on targeted, nontitratable levels of fixed AEC2 ablation. We hypothesized that discrete levels of AEC2 ablation would trigger stereotypical and informative patterns of repair. To this end, we created a transgenic mouse model in which the surfactant protein-C promoter drives expression of a mutant SR39TK herpes simplex virus-1 thymidine kinase specifically in AEC2. Because of the sensitivity of SR39TK, low doses of ganciclovir can be administered to these animals to induce dose-dependent AEC2 depletion ranging from mild (50%) to lethal (82%) levels. We demonstrate that specific levels of AEC2 depletion cause altered expression patterns of apoptosis and repair proteins in surviving AEC2 as well as distinct changes in distal lung morphology, pulmonary function, collagen deposition, and expression of remodeling proteins in whole lung that persist for up to 60 days. We believe SPCTK mice demonstrate the utility of cell-specific expression of the SR39TK transgene for exerting fine control of target cell depletion. Our data demonstrate, for the first time, that specific levels of type 2 alveolar epithelial cell depletion produce characteristic injury repair outcomes. Most importantly, use of these mice will contribute to a better understanding of the role of AEC2 in the initiation of, and response to, lung injury. PMID:26203800

  10. A clinically relevant canine lung cancer model

    SciTech Connect

    Benfield, J.R.; Shors, E.C.; Hammond, W.G.; Paladugu, R.R.; Cohen, A.H.; Jensen, T.; Fu, P.C.; Pak, H.Y.; Teplitz, R.L.

    1981-12-01

    Research on early human lung cancer is difficult; we have sought a canine correlate. Regimens included endobronchial submucosal injections and topical focal applications of benzo(a)pyrene, nitrosomethylurea, dimethylbenzanthracene, and methylcholanthrene, singly or in combinations. Sustained-release discs were placed into lung parenchyma or sutured into major bronchi. Tracheal segments were isolated as cervical pedicle grafts. Gross and histological evolution was reproducible. Columnar and basal hyperplasia and squamous metaplasia were early changes. Atypia occurred within 6 weeks and was found in all dogs within 16 to 18 weeks. Invasive cancers occurred within 8 to 65 months. No tracheal graft developed cancer. Of 15 dogs with parenchymal sustained-release implants, 1 to date has developed cancer in 8 months. Four endobronchial regimens have produced 16 cancers in 56 lungs at risk for 18 to 65 months. No cancers developed in 23 lungs at risk from eight other regimens. Of 10 dogs at risk for unilateral endobronchial cancer, 5 have had cancer. Of 23 dogs with both lungs at risk, 9 developed cancer. We have shown focal carcinogenesis with well-defined pathogenesis and an extended preneoplastic period at predictable sites in a lung cancer model.

  11. Loss of anion transport without increased sodium absorption characterizes newborn porcine cystic fibrosis airway epithelia.

    PubMed

    Chen, Jeng-Haur; Stoltz, David A; Karp, Philip H; Ernst, Sarah E; Pezzulo, Alejandro A; Moninger, Thomas O; Rector, Michael V; Reznikov, Leah R; Launspach, Janice L; Chaloner, Kathryn; Zabner, Joseph; Welsh, Michael J

    2010-12-10

    Defective transepithelial electrolyte transport is thought to initiate cystic fibrosis (CF) lung disease. Yet, how loss of CFTR affects electrolyte transport remains uncertain. CFTR⁻(/)⁻ pigs spontaneously develop lung disease resembling human CF. At birth, their airways exhibit a bacterial host defense defect, but are not inflamed. Therefore, we studied ion transport in newborn nasal and tracheal/bronchial epithelia in tissues, cultures, and in vivo. CFTR⁻(/)⁻ epithelia showed markedly reduced Cl⁻ and HCO₃⁻ transport. However, in contrast to a widely held view, lack of CFTR did not increase transepithelial Na(+) or liquid absorption or reduce periciliary liquid depth. Like human CF, CFTR⁻(/)⁻ pigs showed increased amiloride-sensitive voltage and current, but lack of apical Cl⁻ conductance caused the change, not increased Na(+) transport. These results indicate that CFTR provides the predominant transcellular pathway for Cl⁻ and HCO₃⁻ in porcine airway epithelia, and reduced anion permeability may initiate CF airway disease. PMID:21145458

  12. Hypo-Elastic Model for Lung Parenchyma

    SciTech Connect

    Freed, Alan D.; Einstein, Daniel R.

    2012-03-01

    A simple elastic isotropic constitutive model for the spongy tissue in lung is derived from the theory of hypoelasticity. The model is shown to exhibit a pressure dependent behavior that has been interpreted by some as indicating extensional anisotropy. In contrast, we show that this behavior arises natural from an analysis of isotropic hypoelastic invariants, and is a likely result of non-linearity, not anisotropy. The response of the model is determined analytically for several boundary value problems used for material characterization. These responses give insight into both the material behavior as well as admissible bounds on parameters. The model is characterized against published experimental data for dog lung. Future work includes non-elastic model behavior.

  13. Human models of acute lung injury

    PubMed Central

    Proudfoot, Alastair G.; McAuley, Danny F.; Griffiths, Mark J. D.; Hind, Matthew

    2011-01-01

    Acute lung injury (ALI) is a syndrome that is characterised by acute inflammation and tissue injury that affects normal gas exchange in the lungs. Hallmarks of ALI include dysfunction of the alveolar-capillary membrane resulting in increased vascular permeability, an influx of inflammatory cells into the lung and a local pro-coagulant state. Patients with ALI present with severe hypoxaemia and radiological evidence of bilateral pulmonary oedema. The syndrome has a mortality rate of approximately 35% and usually requires invasive mechanical ventilation. ALI can follow direct pulmonary insults, such as pneumonia, or occur indirectly as a result of blood-borne insults, commonly severe bacterial sepsis. Although animal models of ALI have been developed, none of them fully recapitulate the human disease. The differences between the human syndrome and the phenotype observed in animal models might, in part, explain why interventions that are successful in models have failed to translate into novel therapies. Improved animal models and the development of human in vivo and ex vivo models are therefore required. In this article, we consider the clinical features of ALI, discuss the limitations of current animal models and highlight how emerging human models of ALI might help to answer outstanding questions about this syndrome. PMID:21357760

  14. Basolateral chloride current in human airway epithelia.

    PubMed

    Itani, Omar A; Lamb, Fred S; Melvin, James E; Welsh, Michael J

    2007-10-01

    Electrolyte transport by airway epithelia regulates the quantity and composition of liquid covering the airways. Previous data indicate that airway epithelia can absorb NaCl. At the apical membrane, cystic fibrosis transmembrane conductance regulator (CFTR) provides a pathway for Cl(-) absorption. However, the pathways for basolateral Cl(-) exit are not well understood. Earlier studies, predominantly in cell lines, have reported that the basolateral membrane contains a Cl(-) conductance. However, the properties have varied substantially in different epithelia. To better understand the basolateral Cl(-) conductance in airway epithelia, we studied primary cultures of well-differentiated human airway epithelia. The basolateral membrane contained a Cl(-) current that was inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The current-voltage relationship was nearly linear, and the halide selectivity was Cl(-) > Br(-) > I(-). Several signaling pathways increased the current, including elevation of cellular levels of cAMP, activation of protein kinase C (PKC), and reduction of pH. In contrast, increasing cell Ca(2+) and inducing cell swelling had no effect. The basolateral Cl(-) current was present in both cystic fibrosis (CF) and non-CF airway epithelia. Likewise, airway epithelia from wild-type mice and mice with disrupted genes for ClC-2 or ClC-3 all showed similar Cl(-) currents. These data suggest that the basolateral membrane of airway epithelia possesses a Cl(-) conductance that is not due to CFTR, ClC-2, or ClC-3. Its regulation by cAMP and PKC signaling pathways suggests that coordinated regulation of Cl(-) conductance in both apical and basolateral membranes may be important in controlling transepithelial Cl(-) movement. PMID:17660331

  15. Bioelectric characterization of epithelia from neonatal CFTR knockout ferrets.

    PubMed

    Fisher, John T; Tyler, Scott R; Zhang, Yulong; Lee, Ben J; Liu, Xiaoming; Sun, Xingshen; Sui, Hongshu; Liang, Bo; Luo, Meihui; Xie, Weiliang; Yi, Yaling; Zhou, Weihong; Song, Yi; Keiser, Nicholas; Wang, Kai; de Jonge, Hugo R; Engelhardt, John F

    2013-11-01

    Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4'-diisothiocyano-2,2'-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin-stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)-inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin-inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport. PMID:23782101

  16. Bioelectric Characterization of Epithelia from Neonatal CFTR Knockout Ferrets

    PubMed Central

    Fisher, John T.; Tyler, Scott R.; Zhang, Yulong; Lee, Ben J.; Liu, Xiaoming; Sun, Xingshen; Sui, Hongshu; Liang, Bo; Luo, Meihui; Xie, Weiliang; Yi, Yaling; Zhou, Weihong; Song, Yi; Keiser, Nicholas; Wang, Kai; de Jonge, Hugo R.

    2013-01-01

    Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4′-diisothiocyano-2,2′-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin–stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)–inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin–inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport. PMID:23782101

  17. Collectins and Cationic Antimicrobial Peptides of the Respiratory Epithelia

    PubMed Central

    Grubor, B.; Meyerholz, D. K.; Ackermann, M. R.

    2009-01-01

    The respiratory epithelium is a primary site for the deposition of microorganisms that are acquired during inspiration. The innate immune system of the respiratory tract eliminates many of these potentially harmful agents preventing their colonization. Collectins and cationic antimicrobial peptides are antimicrobial components of the pulmonary innate immune system produced by respiratory epithelia, which have integral roles in host defense and inflammation in the lung. Synthesis and secretion of these molecules are regulated by the developmental stage, hormones, as well as many growth and immunoregulatory factors. The purpose of this review is to discuss antimicrobial innate immune elements within the respiratory tract of healthy and pneumonic lung with emphasis on hydrophilic surfactant proteins and β-defensins. PMID:16966437

  18. Foxg1-Cre Mediated Lrp2 Inactivation in the Developing Mouse Neural Retina, Ciliary and Retinal Pigment Epithelia Models Congenital High Myopia

    PubMed Central

    Obry, Antoine; Santin, Mathieu D.; Ben-Yacoub, Sirine; Pâques, Michel; Amsellem-Levera, Sabine; Bribian, Ana; Simonutti, Manuel; Augustin, Sébastien; Debeir, Thomas; Sahel, José Alain; Christ, Annabel; de Castro, Fernando; Lehéricy, Stéphane; Cosette, Pascal; Kozyraki, Renata

    2015-01-01

    Myopia is a common ocular disorder generally due to increased axial length of the eye-globe. Its extreme form high myopia (HM) is a multifactorial disease leading to retinal and scleral damage, visual impairment or loss and is an important health issue. Mutations in the endocytic receptor LRP2 gene result in Donnai-Barrow (DBS) and Stickler syndromes, both characterized by HM. To clearly establish the link between Lrp2 and congenital HM we inactivated Lrp2 in the mouse forebrain including the neural retina and the retinal and ciliary pigment epithelia. High resolution in vivo MRI imaging and ophthalmological analyses showed that the adult Lrp2-deficient eyes were 40% longer than the control ones mainly due to an excessive elongation of the vitreal chamber. They had an apparently normal intraocular pressure and developed chorioretinal atrophy and posterior scleral staphyloma features reminiscent of human myopic retinopathy. Immunomorphological and ultrastructural analyses showed that increased eye lengthening was first observed by post-natal day 5 (P5) and that it was accompanied by a rapid decrease of the bipolar, photoreceptor and retinal ganglion cells, and eventually the optic nerve axons. It was followed by scleral thinning and collagen fiber disorganization, essentially in the posterior pole. We conclude that the function of LRP2 in the ocular tissues is necessary for normal eye growth and that the Lrp2-deficient eyes provide a unique tool to further study human HM. PMID:26107939

  19. A model of ventilation of the healthy human lung.

    PubMed

    Steimle, K L; Mogensen, M L; Karbing, D S; Bernardino de la Serna, J; Andreassen, S

    2011-02-01

    This paper presents a model of the lung mechanics which simulates the pulmonary alveolar ventilation. The model includes aspects of: the alveolar geometry; pressure due to the chest wall; pressure due to surface tension determined by surfactant activity; pressure due to lung tissue elasticity; and pressure due to the hydrostatic effects of the lung tissue and blood. The cross-sectional area of the lungs in the supine position derived from computed tomography is used to construct a horizontally layered model, which simulates heterogeneous ventilation distribution from the non-dependent to the dependent layers of the lungs. The model is in agreement with experimentally measured hysteresis of the pressure-volume curve of the lungs, static lung compliance, changes in lung depth during breathing and density distributions at total lung capacity (TLC) and residual volume (RV). In the dependent layers of the lungs, alveolar collapse may occur at RV, depending on the assumptions concerning lung tissue elasticity at very low alveolar volumes. The model simulations showed that ventilation increased with depth in the lungs, although not as pronounced as observed experimentally. The model simulates alveolar ventilation including all of the mentioned components of the respiratory system and to be validated against all the above mentioned experimental data. PMID:20655612

  20. KGF alters gene expression in human airway epithelia: potential regulation of the inflammatory response.

    PubMed

    Prince, L S; Karp, P H; Moninger, T O; Welsh, M J

    2001-07-17

    Keratinocyte growth factor (KGF) regulates several functions in adult and developing lung epithelia; it causes proliferation, stimulates secretion of fluid and electrolytes, enhances repair, and may minimize injury. To gain insight into the molecular processes influenced by KGF, we applied KGF to primary cultures of well-differentiated human airway epithelia and used microarray hybridization to assess the abundance of gene transcripts. Of 7,069 genes tested, KGF changed expression levels of 910. Earlier studies showed that KGF causes epithelial proliferation, and as expected, treatment altered expression of numerous genes involved in cell proliferation. We found that KGF stimulated transepithelial Cl(-) transport, but the number of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) transcripts fell. Although transcripts for ClC-1 and ClC-7 Cl(-) channels increased, KGF failed to augment transepithelial Cl(-) transport in CF epithelia, suggesting that KGF-stimulated Cl(-) transport in differentiated airway epithelia depends on the CFTR Cl(-) channel. Interestingly, KGF decreased transcripts for many interferon (IFN)-induced genes. IFN causes trafficking of Stat dimers to the nucleus, where they activate transcription of IFN-induced genes. We found that KGF prevented the IFN-stimulated trafficking of Stat1 from the cytosol to the nucleus, suggesting a molecular mechanism for KGF-mediated suppression of the IFN-signaling pathway. These results suggest that in addition to stimulating proliferation and repair of damaged airway epithelia, KGF stimulates Cl(-) transport and may dampen the response of epithelial cells to inflammatory mediators. PMID:11459923

  1. Functional Roles of Bestrophins in Ocular Epithelia

    PubMed Central

    Marmorstein, Alan D.; Cross, Harold E.; Peachey, Neal S.

    2009-01-01

    There are four members of the bestrophin family of proteins in the human genome, of which two are known to be expressed in the eye. The gene BEST1 (formerly VMD2) which encodes the protein bestrophin-1 (Best1) was first identified in 1998. Mutations in this gene have now been associated with four clinically distinguishable human eye diseases, collectively referred to as “bestrophinopathies”. Over the last decade, laboratories have sought to understand how Best1 mutations could result in eye diseases that range in presentation from macular degeneration to nanophthalmos. The majority of our knowledge comes from studies that have sought to understand how Best1 mutations or dysfunction could induce the classical symptoms of the most common of these diseases: Best vitelliform macular dystrophy (BVMD). BVMD is a dominant trait that is characterized electrophysiologically by a diminished electrooculogram light peak with a normal clinical electroretinogram. This together with the localization of Best1 to the retinal pigment epithelium (RPE) basolateral plasma membrane and data from heterologous expression studies, have led to the proposal that Best1 generates the light peak, and that bestrophins are a family of Ca2+ activated Cl- channels (CaCCs). However, data from Best1 knock-out and knock-in mice, coupled with the recent discovery of a recessive bestrophinopathy suggest that Best1 does not generate the light peak. Recently Best2 was found to be expressed in non-pigmented epithelia in the ciliary body. However, aqueous dynamics in Best2 knock-out mice do not support a role for Best2 as a Cl- channel. Thus, the purported CaCC function of the bestrophins and how loss of this function relates to clinical disease needs to be reassessed. In this article, we examine data obtained from tissue-type and animal models and discuss the current state of bestrophin research, what roles Best1 and Best2 may play in ocular epithelia and ocular electrophysiology, and how perturbation

  2. Genetically engineered mouse models for lung cancer.

    PubMed

    Kwak, I; Tsai, S Y; DeMayo, F J

    2004-01-01

    The lung is a complex organ consisting of numerous cell types that function to ensure sufficient gas exchange to oxygenate the blood. In order to accomplish this function, the lung must be exposed to the external environment and at the same time maintain a homeostatic balance between its function in gas exchange and the maintenance of inflammatory balance. During the past two decades, as molecular methodologies have evolved with the sequencing of entire genomes, the use of in vivo models to elucidate the molecular mechanisms involved in pulmonary physiology and disease have increased. The mouse has emerged as a potent model to investigate pulmonary physiology due to the explosion in molecular methods that now allow for the developmental and tissue-specific regulation of gene transcription. Initial efforts to manipulate gene expression in the mouse genome resulted in the generation of transgenic mice characterized by the constitutive expression of a specific gene and knockout mice characterized by the ablation of a specific gene. The utility of these original mouse models was limited, in many cases, by phenotypes resulting in embryonic or neonatal lethality that prevented analysis of the impact of the genetic manipulation on pulmonary biology. Second-generation transgenic mouse models employ multiple strategies that can either activate or silence gene expression thereby providing extensive temporal and spatial control of the experimental parameters of gene expression. These highly regulated mouse models are intended to serve as a foundation for further investigation of the molecular basis of human disease such as tumorigenesis. This review describes the principles, progress, and application of systems that are currently employed in the conditional regulation of gene expression in the investigation of lung cancer. PMID:14977417

  3. LUNG MODEL CASTING TECHNIQUES FOR INTERSPECIES MORPHOMETRIC COMPARISONS

    EPA Science Inventory

    Techniques have been developed for casting both solid and hollow lung models from lung specimens. These techniques have been used to make casts of rat, rabbit, baboon, and human lungs and may be used for other species. An air line at a positive pressure of 25 cm of water is conne...

  4. Dynamic epithelia of the developing vertebrate face

    PubMed Central

    Choe, Chong Pyo; Crump, J. Gage

    2015-01-01

    A segmental series of endoderm-derived pouch and ectoderm-derived cleft epithelia act as signaling centers in the developing face. Their precise morphogenesis is therefore essential for proper patterning of the vertebrate head. Intercellular adhesion and polarity are highly dynamic within developing facial epithelial cells, with signaling from the adjacent mesenchyme controlling both epithelial character and directional migration. Endodermal and ectodermal epithelia fuse to form the primary mouth and gill slits, which involves basement membrane dissolution, cell intercalations, and apoptosis, as well as undergo further morphogenesis to generate the middle ear cavity and glands of the neck. Recent studies of facial epithelia are revealing both core programs of epithelial morphogenesis and insights into the coordinated assembly of the vertebrate head. PMID:25748249

  5. Hepatocyte growth factor/scatter factor effects on epithelia. Regulation of intercellular junctions in transformed and nontransformed cell lines, basolateral polarization of c-met receptor in transformed and natural intestinal epithelia, and induction of rapid wound repair in a transformed model epithelium.

    PubMed

    Nusrat, A; Parkos, C A; Bacarra, A E; Godowski, P J; Delp-Archer, C; Rosen, E M; Madara, J L

    1994-05-01

    Intestinal epithelial cells rest on a fibroblast sheath. Thus, factors produced by these fibroblasts may influence epithelial function in a paracrine fashion. We examined modulation of intestinal epithelial function by one such fibroblast product, scatter factor/hepatocyte growth factor (HGF/SF). This effect was studied in vitro by using model T84 intestinal epithelial cells. When applied to confluent T84 monolayers, HGF/SF attenuates transepithelial resistance to passive ion flow in a dose-dependent manner (maximum fall at 300 ng/ml, 28% control monolayer resistance, P < 0.001, ED50 of 1.2 nM), t1/2 of 20 h. This functional effect of HGF/SF and distribution of its receptor, c-met, are polarized to the basolateral membranes of T84 intestinal epithelial cells. HGF/SF effects on resistance are not attributable to altered transcellular resistance (opening of Cl- and/or basolateral K+ channels), cytotoxicity, or enhanced cell proliferation; they therefore represent specific regulation of paracellular tight junction resistance. Analysis with biochemically purified rodent HGF/SF and Madin-Darby canine kidney cells reveals that effects on paracellular tight junctions also occur in other nontransformed epithelia. Binding of HGF/SF to its receptor in T84 intestinal epithelial cells is accompanied by tyrosine phosphorylation of the receptor. Because loosening of intercellular junctions between cells could facilitate separation, spreading, and migration of epithelial cells during physiologic processes such as wound resealing, we determined the effects of HGF/SF on intestinal epithelial wound resealing using our previously published in vitro model (Nusrat, A., C. Delp, and J. L. Madara. 1992. J. Clin. Invest. 89:1501-1511). HGF/SF markedly enhanced wound closure (> 450% increase in rate, P < 0.001) by influencing the migratory and spreading response in not only cells adjoining the wound but also cells many positions removed from the wound. We thus speculate that HGF/SF may

  6. A mathematical model of lung parenchyma.

    PubMed

    Karakaplan, A D; Bieniek, M P; Skalak, R

    1980-05-01

    The geometry of the proposed model of the parenchyma of a mammalian lung reproduces a cluster of alveoli arranged around a lowest-level air duct. The alveolar walls are assumed to be nonlinear elastic membranes, whose properties are described in terms of a strain energy function which reflects the hardening character of the stress-strain curve. The effect of the surfactant is included in terms of a variable (area-dependent) surface tension. Analyses of various mechanical processes in the parenchyma are performed with the aid of the finite element method, with the geometric and physical nonlinearities of the problem taken into account. PMID:6893348

  7. Irreversible Electroporation in a Swine Lung Model

    SciTech Connect

    Dupuy, Damian E.; Aswad, Bassam; Ng, Thomas

    2011-04-15

    Purpose: This study was designed to evaluate the safety and tissue effects of IRE in a swine lung model. Methods: This study was approved by the institutional animal care committee. Nine anesthetized domestic swine underwent 15 percutaneous irreversible electroporation (IRE) lesion creations (6 with bipolar and 3 with 3-4 monopolar electrodes) under fluoroscopic guidance and with pancuronium neuromuscular blockade and EKG gating. IRE electrodes were placed into the central and middle third of the right mid and lower lobes in all animals. Postprocedure PA and lateral chest radiographs were obtained to evaluate for pneumothorax. Three animals were sacrificed at 2 weeks and six at 4 weeks. Animals underwent high-resolution CT scanning and PA and lateral radiographs 1 h before sacrifice. The treated lungs were removed en bloc, perfused with formalin, and sectioned. Gross pathologic and microscopic changes after standard hematoxylin and eosin staining were analyzed within the areas of IRE lesion creation. Results: No significant adverse events were identified. CT showed focal areas of spiculated high density ranging in greatest diameter from 1.1-2.2 cm. On gross inspection of the sectioned lung, focal areas of tan discoloration and increased density were palpated in the areas of IRE. Histological analysis revealed focal areas of diffuse alveolar damage with fibrosis and inflammatory infiltration that respected the boundaries of the interlobular septae. No pathological difference could be discerned between the 2- and 4-week time points. The bronchioles and blood vessels within the areas of IRE were intact and did not show signs of tissue injury. Conclusion: IRE creates focal areas of diffuse alveolar damage without creating damage to the bronchioles or blood vessels. Short-term safety in a swine model appears to be satisfactory.

  8. Modeling Airflow Using Subject-Specific 4DCT-Based Deformable Volumetric Lung Models.

    PubMed

    Ilegbusi, Olusegun J; Li, Zhiliang; Seyfi, Behnaz; Min, Yugang; Meeks, Sanford; Kupelian, Patrick; Santhanam, Anand P

    2012-01-01

    Lung radiotherapy is greatly benefitted when the tumor motion caused by breathing can be modeled. The aim of this paper is to present the importance of using anisotropic and subject-specific tissue elasticity for simulating the airflow inside the lungs. A computational-fluid-dynamics (CFD) based approach is presented to simulate airflow inside a subject-specific deformable lung for modeling lung tumor motion and the motion of the surrounding tissues during radiotherapy. A flow-structure interaction technique is employed that simultaneously models airflow and lung deformation. The lung is modeled as a poroelastic medium with subject-specific anisotropic poroelastic properties on a geometry, which was reconstructed from four-dimensional computed tomography (4DCT) scan datasets of humans with lung cancer. The results include the 3D anisotropic lung deformation for known airflow pattern inside the lungs. The effects of anisotropy are also presented on both the spatiotemporal volumetric lung displacement and the regional lung hysteresis. PMID:23365554

  9. Modeling Airflow Using Subject-Specific 4DCT-Based Deformable Volumetric Lung Models

    PubMed Central

    Ilegbusi, Olusegun J.; Li, Zhiliang; Seyfi, Behnaz; Min, Yugang; Meeks, Sanford; Kupelian, Patrick; Santhanam, Anand P.

    2012-01-01

    Lung radiotherapy is greatly benefitted when the tumor motion caused by breathing can be modeled. The aim of this paper is to present the importance of using anisotropic and subject-specific tissue elasticity for simulating the airflow inside the lungs. A computational-fluid-dynamics (CFD) based approach is presented to simulate airflow inside a subject-specific deformable lung for modeling lung tumor motion and the motion of the surrounding tissues during radiotherapy. A flow-structure interaction technique is employed that simultaneously models airflow and lung deformation. The lung is modeled as a poroelastic medium with subject-specific anisotropic poroelastic properties on a geometry, which was reconstructed from four-dimensional computed tomography (4DCT) scan datasets of humans with lung cancer. The results include the 3D anisotropic lung deformation for known airflow pattern inside the lungs. The effects of anisotropy are also presented on both the spatiotemporal volumetric lung displacement and the regional lung hysteresis. PMID:23365554

  10. Lacritin Rescues Stressed Epithelia via Rapid Forkhead Box O3 (FOXO3)-associated Autophagy That Restores Metabolism*

    PubMed Central

    Wang, Ningning; Zimmerman, Keith; Raab, Ronald W.; McKown, Robert L.; Hutnik, Cindy M. L.; Talla, Venu; Tyler, Milton F.; Lee, Jae K.; Laurie, Gordon W.

    2013-01-01

    Homeostasis is essential for cell survival. However, homeostatic regulation of surface epithelia is poorly understood. The eye surface, lacking the cornified barrier of skin, provides an excellent model. Tears cover the surface of the eye and are deficient in dry eye, the most common eye disease affecting at least 5% of the world's population. Only a tiny fraction of the tear proteome appears to be affected, including lacritin, an epithelium-selective mitogen that promotes basal tearing when topically applied to rabbit eyes. Here we show that homeostasis of cultured corneal epithelia is entirely lacritin-dependent and elucidate the mechanism as a rapid autophagic flux to promptly restore cellular metabolism and mitochondrial fusion in keeping with the short residence time of lacritin on the eye. Accelerated flux appears to be derived from lacritin-stimulated acetylation of FOXO3 as a novel ligand for ATG101 and coupling of stress-acetylated FOXO1 with ATG7 (which remains uncoupled without lacritin) and be sufficient to selectively divert huntingtin mutant Htt103Q aggregates largely without affecting non-aggregated Htt25Q. This is in keeping with stress as a prerequisite for lacritin-stimulated autophagy. Lacritin targets the cell surface proteoglycan syndecan-1 via its C-terminal amino acids Leu108-Leu109-Phe112 and is also available in saliva, plasma, and lung lavage. Thus, lacritin may promote epithelial homeostasis widely. PMID:23640897

  11. Motile Cilia of Human Airway Epithelia Are Chemosensory

    PubMed Central

    Shah, Alok S; Ben-Shahar, Yehuda; Moninger, Thomas O; Kline, Joel N; Welsh, Michael J

    2010-01-01

    Cilia are microscopic projections that extend from eukaryotic cells. There are two general types of cilia; primary cilia serve as sensory organelles, whereas motile cilia exert mechanical force. The motile cilia emerging from human airway epithelial cells propel harmful inhaled material out of the lung. We found that these cells express sensory bitter taste receptors, which localized on motile cilia. Bitter compounds increased the intracellular Ca2+ concentration and stimulated ciliary beat frequency. Thus, airway epithelia contain a cell-autonomous system in which motile cilia both sense noxious substances entering airways and initiate a defensive mechanical mechanism to eliminate the offending compound. Hence, like primary cilia, classical motile cilia also contain sensors to detect the external environment. PMID:19628819

  12. Developing Epithelia: What the Eye Cannot Grasp.

    PubMed

    Tosi, Sébastien; Milán, Marco

    2016-01-11

    In this issue of Developmental Cell, Heller et al. (2016) introduce EpiTools, a new open-source image analysis toolkit that provides user-friendly graphical interfaces to perform automatic cell-based measurements from fluorescence microscopy time-lapse images of growing epithelia. PMID:26766439

  13. Lung tumor motion prediction during lung brachytherapy using finite element model

    NASA Astrophysics Data System (ADS)

    Shirzadi, Zahra; Sadeghi Naini, Ali; Samani, Abbas

    2012-02-01

    A biomechanical model is proposed to predict deflated lung tumor motion caused by diaphragm respiratory motion. This model can be very useful for targeting the tumor in tumor ablative procedures such as lung brachytherapy. To minimize motion within the target lung, these procedures are performed while the lung is deflated. However, significant amount of tissue deformation still occurs during respiration due to the diaphragm contact forces. In the absence of effective realtime image guidance, biomechanical models can be used to estimate tumor motion as a function of diaphragm's position. To develop this model, Finite Element Method (FEM) was employed. To demonstrate the concept, we conducted an animal study of an ex-vivo porcine deflated lung with a tumor phantom. The lung was deformed by compressing a diaphragm mimicking cylinder against it. Before compression, 3D-CT image of this lung was acquired, which was segmented and turned into FE mesh. The lung tissue was modeled as hyperelastic material with a contact loading to calculate the lung deformation and tumor motion during respiration. To validate the results from FE model, the motion of a small area on the surface close to the tumor was tracked while the lung was being loaded by the cylinder. Good agreement was demonstrated between the experiment results and simulation results. Furthermore, the impact of tissue hyperelastic parameters uncertainties in the FE model was investigated. For this purpose, we performed in-silico simulations with different hyperelastic parameters. This study demonstrated that the FEM was accurate and robust for tumor motion prediction.

  14. Incorporation of Adeno-Associated Virus in a Calcium Phosphate Coprecipitate Improves Gene Transfer to Airway Epithelia In Vitro and In Vivo

    PubMed Central

    Walters, Robert W.; Duan, Dongsheng; Engelhardt, John F.; Welsh, Michael J.

    2000-01-01

    Adeno-associated virus (AAV) is inefficient at infecting differentiated airway epithelia because of a lack of receptors at the apical surface. We hypothesized that incorporation of AAV in a calcium phosphate coprecipitate would circumvent this barrier. Interestingly, coprecipitation of AAV type 2 improved gene transfer to differentiated human airway epithelia in vitro and to the mouse lung in vivo. These results suggest that delivery of AAV as a CaPi coprecipitate may significantly enhance its utility for gene transfer to the airway epithelia in vivo. PMID:10590145

  15. Persistent Gene Expression in Mouse Nasal Epithelia following Feline Immunodeficiency Virus-Based Vector Gene Transfer

    PubMed Central

    Sinn, Patrick L.; Burnight, Erin R.; Hickey, Melissa A.; Blissard, Gary W.; McCray, Paul B.

    2005-01-01

    Gene transfer development for treatment or prevention of cystic fibrosis lung disease has been limited by the inability of vectors to efficiently and persistently transduce airway epithelia. Influenza A is an enveloped virus with natural lung tropism; however, pseudotyping feline immunodeficiency virus (FIV)-based lentiviral vector with the hemagglutinin envelope protein proved unsuccessful. Conversely, pseudotyping FIV with the envelope protein from influenza D (Thogoto virus GP75) resulted in titers of 106 transducing units (TU)/ml and conferred apical entry into well-differentiated human airway epithelial cells. Baculovirus GP64 envelope glycoproteins share sequence identity with influenza D GP75 envelope glycoproteins. Pseudotyping FIV with GP64 from three species of baculovirus resulted in titers of 107 to 109 TU/ml. Of note, GP64 from Autographa californica multicapsid nucleopolyhedrovirus resulted in high-titer FIV preparations (∼109 TU/ml) and conferred apical entry into polarized primary cultures of human airway epithelia. Using a luciferase reporter gene and bioluminescence imaging, we observed persistent gene expression from in vivo gene transfer in the mouse nose with A. californica GP64-pseudotyped FIV (AcGP64-FIV). Longitudinal bioluminescence analysis documented persistent expression in nasal epithelia for ∼1 year without significant decline. According to histological analysis using a LacZ reporter gene, olfactory and respiratory epithelial cells were transduced. In addition, methylcellulose-formulated AcGP64-FIV transduced mouse nasal epithelia with much greater efficiency than similarly formulated vesicular stomatitis virus glycoprotein-pseudotyped FIV. These data suggest that AcGP64-FIV efficiently transduces and persistently expresses a transgene in nasal epithelia in the absence of agents that disrupt the cellular tight junction integrity. PMID:16188984

  16. Large-scale gene discovery in human airway epithelia reveals novel transcripts.

    PubMed

    Scheetz, Todd E; Zabner, Joseph; Welsh, Michael J; Coco, Justin; Eyestone, Mari de Fatima; Bonaldo, Maria; Kucaba, Tamara; Casavant, Thomas L; Soares, M Bento; McCray, Paul B

    2004-03-12

    The airway epithelium represents an important barrier between the host and the environment. It is a first site of contact with pathogens, particulates, and other stimuli, and has evolved the means to dynamically respond to these challenges. In an effort to define the transcript profile of airway epithelia, we created and sequenced cDNA libraries from cystic fibrosis (CF) and non-CF epithelia and from human lung tissue. Sequencing of these libraries produced approximately 53,000 3'-expressed sequence tags (3'-ESTs). From these, a nonredundant UniGene set of more than 19,000 sequences was generated. Despite the relatively small contribution of airway epithelia to the total mass of the lung, focused gene discovery in this tissue yielded novel results. The ESTs included several thousand transcripts (6,416) not previously identified from cDNA sequences as expressed in the lung. Among the abundant transcripts were several genes involved in host defense. Most importantly, the set also included 879 3'-ESTs that appear to be novel sequences not previously represented in the National Center for Biotechnology Information UniGene collection. This UniGene set should be useful for studies of pulmonary diseases involving the airway epithelium including cystic fibrosis, respiratory infections and asthma. It also provides a reagent for large-scale expression profiling. PMID:14701920

  17. A Novel Bioluminescence Orthotopic Mouse Model for Advanced Lung Cancer

    PubMed Central

    Li, Bo; Torossian, Artour; Li, Wenyan; Schleicher, Stephen; Niu, Kathy; Giacalone, Nicholas J.; Kim, Sung June; Chen, Heidi; Gonzalez, Adriana; Moretti, Luigi; Lu, Bo

    2011-01-01

    Lung cancer is the leading cause of cancer-related death in the United States despite recent advances in our understanding of this challenging disease. An animal model for high-throughput screening of therapeutic agents for advanced lung cancer could help promote the development of more successful treatment interventions. To develop our orthotopic lung cancer model, luciferase-expressing A549 cancer cells were injected into the mediastinum of athymic nude mice. To determine whether the model would allow easy monitoring of response to therapeutic interventions, tumors were treated with 30 mg/kg Paclitaxel or were irradiated with 5 fractions of 2 Gy, and tumor burden was monitored using bioluminescence imaging. Evidence of radiation-induced lung injury was assessed using immunohistochemical staining for phospho-Smad2/3 and cleaved caspase-3. We found that tumor implantation recapitulated advanced human lung cancer as evidenced by tumor establishment and proliferation within the mediastinum. The tumor responded to Paclitaxel or radiation as shown by decreased tumor bioluminescence and improved overall survival. Immunohistochemistry revealed increased phospho-Smad2/3 and cleaved caspase-3 in irradiated lungs, consistent with radiation-induced lung injury. This orthotopic lung cancer model may help provide a method to assess therapeutic interventions in a preclinical setting that recapitulates locally advanced lung cancer. PMID:21663394

  18. Analytic Intermodel Consistent Modeling of Volumetric Human Lung Dynamics.

    PubMed

    Ilegbusi, Olusegun; Seyfi, Behnaz; Neylon, John; Santhanam, Anand P

    2015-10-01

    Human lung undergoes breathing-induced deformation in the form of inhalation and exhalation. Modeling the dynamics is numerically complicated by the lack of information on lung elastic behavior and fluid-structure interactions between air and the tissue. A mathematical method is developed to integrate deformation results from a deformable image registration (DIR) and physics-based modeling approaches in order to represent consistent volumetric lung dynamics. The computational fluid dynamics (CFD) simulation assumes the lung is a poro-elastic medium with spatially distributed elastic property. Simulation is performed on a 3D lung geometry reconstructed from four-dimensional computed tomography (4DCT) dataset of a human subject. The heterogeneous Young's modulus (YM) is estimated from a linear elastic deformation model with the same lung geometry and 4D lung DIR. The deformation obtained from the CFD is then coupled with the displacement obtained from the 4D lung DIR by means of the Tikhonov regularization (TR) algorithm. The numerical results include 4DCT registration, CFD, and optimal displacement data which collectively provide consistent estimate of the volumetric lung dynamics. The fusion method is validated by comparing the optimal displacement with the results obtained from the 4DCT registration. PMID:26292034

  19. Computer modeling of lung cancer diagnosis-to-treatment process

    PubMed Central

    Ju, Feng; Lee, Hyo Kyung; Osarogiagbon, Raymond U.; Yu, Xinhua; Faris, Nick

    2015-01-01

    We introduce an example of a rigorous, quantitative method for quality improvement in lung cancer care-delivery. Computer process modeling methods are introduced for lung cancer diagnosis, staging and treatment selection process. Two types of process modeling techniques, discrete event simulation (DES) and analytical models, are briefly reviewed. Recent developments in DES are outlined and the necessary data and procedures to develop a DES model for lung cancer diagnosis, leading up to surgical treatment process are summarized. The analytical models include both Markov chain model and closed formulas. The Markov chain models with its application in healthcare are introduced and the approach to derive a lung cancer diagnosis process model is presented. Similarly, the procedure to derive closed formulas evaluating the diagnosis process performance is outlined. Finally, the pros and cons of these methods are discussed. PMID:26380181

  20. Lung cancer in never smokers Epidemiology and risk prediction models

    PubMed Central

    McCarthy, William J.; Meza, Rafael; Jeon, Jihyoun; Moolgavkar, Suresh

    2012-01-01

    In this chapter we review the epidemiology of lung cancer incidence and mortality among never smokers/ nonsmokers and describe the never smoker lung cancer risk models used by CISNET modelers. Our review focuses on those influences likely to have measurable population impact on never smoker risk, such as secondhand smoke, even though the individual-level impact may be small. Occupational exposures may also contribute importantly to the population attributable risk of lung cancer. We examine the following risk factors in this chapter: age, environmental tobacco smoke, cooking fumes, ionizing radiation including radon gas, inherited genetic susceptibility, selected occupational exposures, preexisting lung disease, and oncogenic viruses. We also compare the prevalence of never smokers between the three CISNET smoking scenarios and present the corresponding lung cancer mortality estimates among never smokers as predicted by a typical CISNET model. PMID:22882894

  1. Non-animal models of epithelial barriers (skin, intestine and lung) in research, industrial applications and regulatory toxicology.

    PubMed

    Gordon, Sarah; Daneshian, Mardas; Bouwstra, Joke; Caloni, Francesca; Constant, Samuel; Davies, Donna E; Dandekar, Gudrun; Guzman, Carlos A; Fabian, Eric; Haltner, Eleonore; Hartung, Thomas; Hasiwa, Nina; Hayden, Patrick; Kandarova, Helena; Khare, Sangeeta; Krug, Harald F; Kneuer, Carsten; Leist, Marcel; Lian, Guoping; Marx, Uwe; Metzger, Marco; Ott, Katharina; Prieto, Pilar; Roberts, Michael S; Roggen, Erwin L; Tralau, Tewes; van den Braak, Claudia; Walles, Heike; Lehr, Claus-Michael

    2015-01-01

    Models of the outer epithelia of the human body - namely the skin, the intestine and the lung - have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, validation and standardization, acceptance, and the need for simplicity versus complexity were focal themes of the discussions. The outcomes of workshop presentations and discussions, in relation to both current status and future directions in the utilization and development of epithelial barrier models, are presented by the attending experts in the current report. PMID:26536291

  2. Heart and lung support interaction--modeling and simulation.

    PubMed

    Darowski, M

    2000-01-01

    Mechanical support of the lungs used to preserve life or during any kind of surgery may have an adverse effect on the cardiovascular system. Usually, positive pressure in alveoli diminishes lung perfusion, venous return and cardiac output. Positive pressure during the respiratory cycle is transfered into the thoracic space. The aim of this study was to assess how synchronization of the respirator with spontaneous breathing influences the distribution of pressure and ventilation in nonhomogeneous lungs and how it should influence hemodynamics. For this purpose a multicompartmental model of respiratory system mechanics was used in the electrical analog of a respirator-lung circuit, which enabled us to simultaneously simulate ventilatory support and spontaneous breathing. Mechanical properties of the respiratory system were modeled by lumped parameters: resistances and capacitances of constant values, independent of lung volume or inspiratory flow changes. A multicompartmental model of the respiratory system enabled us to simulate lung pathology characterized by non-homogeneity of the mechanical properties of the different parts of the lungs. The results of simulations presented in the paper enable us to conclude that lung volume increase, independent of the respirator-patient breathing synchronization, may be modeled as the increase in pulmonary vascular resistance and alveolar pressure increase, dependent on respirator-patient breathing synchronization, may be averaged by esophageous balloon measurements which show intrathoracic pressure changes. PMID:11014677

  3. Use of cultured epithelia to study transport and its regulation.

    PubMed

    Handler, J S

    1983-09-01

    Epithelial cells from a variety of species and organs form polarized epithelia in culture. When epithelia are grown on a porous surface, such as a millipore filter, transport can be studied using adaptations of standard techniques. In the few years in which cultured epithelia have been studied by transport physiologists, most work has been focused on identification and description of the differentiated transport exhibited by cultured epithelia. Epithelia formed by a continuous line of cells derived from pig kidney (LLC-PK1) exhibit sodium-coupled glucose transport similar to that of the proximal tubule and have vasopressin-sensitive adenylate cyclase that has been studied in great detail. Also of interest are epithelia formed by continuous lines of cells derived from amphibian kidney (A6) and from amphibian urinary bladder (TBM). Each line forms epithelia that have high electrical resistance and amiloride-sensitive sodium transport. Transport is stimulated by aldosterone and by cAMP or hormones that raise cell cAMP levels. In LLC-PK1 and in A6 epithelia, transport and the response to hormones can be manipulated by manipulating the culture conditions. Cultured epithelia have also been used to explore the cell biology of epithelia. Most interesting in this regard are studies of the development and maintenance of epithelial cell polarity. This approach should be especially valuable. PMID:6317789

  4. Implications of the ICRP Task Group's proposed lung model for internal dose assessments in the mineral sands industry

    SciTech Connect

    James, A.C. ); Birchall, A. )

    1990-09-01

    The ICRP Task Group on Respiratory Tract Models for Radiological Projection is proposing a model to describe the deposition, clearance, retention and dosimetry of inhaled radionuclides for dose-intake calculations and interpretation of bioassay data. The deposition model takes into account new data on the regional deposition of aerosol particles in human lung and the inhalability of large particles. The clearance model treats clearance as competition between mechanical transport, which moves particles to the gastro-intestinal tract and lymph nodes, and the translocation of material to blood. This provides a realistic estimate of the amount of a given material (such as mineral sand) that is absorbed systemically, and its variation with aerosol size. The proposed dosimetry model takes into account the relative sensitivities of the various tissue components of the respiratory tract. A new treatment of dose received by epithelia in the tracheo-bronchiolar and extrathoracic regions is proposed. This paper outlines the novel features of the task group model, and then examines the impact that adoption of the model may have on the assessment of doses from occupational exposures to mineral sands and thoron progeny. 39 refs., 15 figs., 6 tabs.

  5. NNK-Induced Lung Tumors: A Review of Animal Model

    PubMed Central

    Zheng, Hua-Chuan; Takano, Yasuo

    2011-01-01

    The incidence of lung adenocarcinoma has been remarkably increasing in recent years due to the introduction of filter cigarettes and secondary-hand smoking because the people are more exposed to higher amounts of nitrogen oxides, especially 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK), which is widely applied in animal model of lung tumors. In NNK-induced lung tumors, genetic mutation, chromosome instability, gene methylation, and activation of oncogenes have been found so as to disrupt the expression profiles of some proteins or enzymes in various cellular signal pathways. Transgenic animal with specific alteration of lung cancer-related molecules have also been introduced to clarify the molecular mechanisms of NNK in the pathogenesis and development of lung tumors. Based on these animal models, many antioxidant ingredients and antitumor chemotherapeutic agents have been proved to suppress the NNK-induced lung carcinogenesis. In the future, it is necessary to delineate the most potent biomarkers of NNK-induced lung tumorigenesis, and to develop efficient methods to fight against NNK-associated lung cancer using animal models. PMID:21559252

  6. Loss of anion transport without increased sodium absorption characterizes newborn porcine cystic fibrosis airway epithelia

    PubMed Central

    Chen, Jeng-Haur; Stoltz, David A.; Karp, Philip H.; Ernst, Sarah E.; Pezzulo, Alejandro A.; Moninger, Thomas O.; Rector, Michael V.; Reznikov, Leah R.; Launspach, Janice L.; Chaloner, Kathryn; Zabner, Joseph; Welsh, Michael J.

    2011-01-01

    SUMMARY Defective transepithelial electrolyte transport is thought to initiate cystic fibrosis (CF) lung disease. Yet, how loss of CFTR affects electrolyte transport remains uncertain. CFTR−/− pigs spontaneously develop lung disease resembling human CF. At birth, their airways exhibit a bacterial host defense defect, but are not inflamed. Therefore, we studied ion transport in newborn nasal and tracheal/bronchial epithelia in tissue, cultures, and in vivo. CFTR−/− epithelia showed markedly reduced Cl− and HCO3− transport. However, in contrast to a widely held view, lack of CFTR did not increase transepithelial Na+ or liquid absorption or reduce periciliary liquid depth. Like human CF, CFTR−/− pigs showed increased amiloride-sensitive voltage and current, but lack of apical Cl− conductance caused the change, not increased Na+ transport. These results indicate that CFTR provides the predominant transcellular pathway for Cl− and HCO3− in porcine airway epithelia, and reduced anion permeability may initiate CF airway disease. PMID:21145458

  7. A Lung Segmental Model of Chronic Pseudomonas Infection in Sheep

    PubMed Central

    Collie, David; Govan, John; Wright, Steven; Thornton, Elisabeth; Tennant, Peter; Smith, Sionagh; Doherty, Catherine; McLachlan, Gerry

    2013-01-01

    Background Chronic lung infection with Pseudomonas aeruginosa is a major contributor to morbidity, mortality and premature death in cystic fibrosis. A new paradigm for managing such infections is needed, as are relevant and translatable animal models to identify and test concepts. We sought to improve on limitations associated with existing models of infection in small animals through developing a lung segmental model of chronic Pseudomonas infection in sheep. Methodology/Principal Findings Using local lung instillation of P. aeruginosa suspended in agar beads we were able to demonstrate that such infection led to the development of a suppurative, necrotising and pyogranulomatous pneumonia centred on the instilled beads. No overt evidence of organ or systemic compromise was apparent in any animal during the course of infection. Infection persisted in the lungs of individual animals for as long as 66 days after initial instillation. Quantitative microbiology applied to bronchoalveolar lavage fluid derived from infected segments proved an insensitive index of the presence of significant infection in lung tissue (>104 cfu/g). Conclusions/Significance The agar bead model of chronic P. aeruginosa lung infection in sheep is a relevant platform to investigate both the pathobiology of such infections as well as novel approaches to their diagnosis and therapy. Particular ethical benefits relate to the model in terms of refining existing approaches by compromising a smaller proportion of the lung with infection and facilitating longitudinal assessment by bronchoscopy, and also potentially reducing animal numbers through facilitating within-animal comparisons of differential therapeutic approaches. PMID:23874438

  8. CFTR–SLC26 transporter interactions in epithelia

    PubMed Central

    2012-01-01

    Transport mechanisms that mediate the movements of anions must be coordinated tightly in order to respond appropriately to physiological stimuli. This process is of paramount importance in the function of diverse epithelial tissues of the body, such as, for example, the exocrine pancreatic duct and the airway epithelia. Disruption of any of the finely tuned components underlying the transport of anions such as Cl−, HCO3−, SCN−, and I− may contribute to a plethora of disease conditions. In many anion-secreting epithelia, the interactions between the cystic fibrosis transmembrane conductance regulator (CFTR) and solute carrier family 26 (SLC26) transporters determine the final exit of anions across the apical membrane and into the luminal compartment. The molecular identification of CFTR and many SLC26 members has enabled the acquisition of progressively more detailed structural information about these transport molecules. Studies employing a vast array of increasingly sophisticated approaches have culminated in a current working model which places these key players within an interactive complex, thereby setting the stage for future work. PMID:22685498

  9. Mechanical Forces Mediate Localized Topological Change in Epithelia

    PubMed Central

    Li, Yingzi; Naveed, Hammad; Kachalo, Sema; Xu, Lisa X.; Liang, Jie

    2013-01-01

    Regulation of cell growth and proliferation has a fundamental role in tissue development, organogenesis, and disease progression. Conserved distribution of the number of sides of cells with a mean value of six was found in a variety of proliferating epithelia. Previous studies have shown that clones of proliferating cells bounded by quiescent cells have fewer sides than normal epithelia. However, the mechanisms for mediating such localized topological change remain poorly understood. In this study, we use a two-dimensional vertex model with consideration of mechanical forces to investigate how differential proliferation and forces can influence cell shape and tissue morphogenesis, and how they may lead to distorted topological change. We find that differential proliferation alone is insufficient to affect the topology of boundary proliferating cells. Rather, increased surface tension on the boundary, in addition to differential proliferation, can significantly decrease the average number of cell sides. Our results are consistent with experimental observations. We conclude that mechanical forces in addition to localized differential proliferation are required to produce the distorted topological change which significantly impacts the overall cell shape and tissue morphogenesis. PMID:22254279

  10. Hematopoietic lineage skewing and intestinal epithelia degeneration in aged mice with telomerase RNA component deletion.

    PubMed

    Chen, Jichun; Bryant, Mark A; Dent, James J; Sun, Yu; Desierto, Marie J; Young, Neal S

    2015-12-01

    A deletion of a telomerase RNA component (Terc(-/-)) in C57BL/6 (B6) mice resulted in hematopoietic lineage skewing with increased neutrophils and CD11b(+) myeloid cells and decreased red blood cells and CD45R(+) B lymphocytes when animals reach ages older than 12 months. There was no decline in bone marrow (BM) c-Kit(+)Sca-1(+)Lin(-) (KSL) cells in old Terc(-/-) mice, and the lineage skewing phenomenon was not transferred when BM cells from old Terc(-/-) donors were transplanted into young B6 recipients. Necropsy and histological examinations found minimal to no change in the lung, spleen and liver but detected severe epithelia degeneration, ulceration and infection in small and large intestines, leading to enteritis, typhlitis and colitis in old Terc(-/-) mice. In a mouse model of dextran-sulfate-sodium-induced typhlitis and colitis, development of intestinal pathology was associated with increases in neutrophils and CD11b(+) myeloid cells and a decrease in CD45R(+) B cells, similar to those observed in old Terc(-/-) mice. Treatment of 11-13 month old Terc(-/-) mice with antibiotic trimethoprim-sulfa water reduced neutrophils and myeloid cells and increased B lymphocytes in the blood, indicating that mitigation of intestinal infection and inflammation could alleviate hematological abnormalities in old Terc(-/-) animals. PMID:26523501

  11. Toxicity of aged gasoline exhaust particles to normal and diseased airway epithelia.

    PubMed

    Künzi, Lisa; Krapf, Manuel; Daher, Nancy; Dommen, Josef; Jeannet, Natalie; Schneider, Sarah; Platt, Stephen; Slowik, Jay G; Baumlin, Nathalie; Salathe, Matthias; Prévôt, André S H; Kalberer, Markus; Strähl, Christof; Dümbgen, Lutz; Sioutas, Constantinos; Baltensperger, Urs; Geiser, Marianne

    2015-01-01

    Particulate matter (PM) pollution is a leading cause of premature death, particularly in those with pre-existing lung disease. A causative link between particle properties and adverse health effects remains unestablished mainly due to complex and variable physico-chemical PM parameters. Controlled laboratory experiments are required. Generating atmospherically realistic aerosols and performing cell-exposure studies at relevant particle-doses are challenging. Here we examine gasoline-exhaust particle toxicity from a Euro-5 passenger car in a uniquely realistic exposure scenario, combining a smog chamber simulating atmospheric ageing, an aerosol enrichment system varying particle number concentration independent of particle chemistry, and an aerosol deposition chamber physiologically delivering particles on air-liquid interface (ALI) cultures reproducing normal and susceptible health status. Gasoline-exhaust is an important PM source with largely unknown health effects. We investigated acute responses of fully-differentiated normal, distressed (antibiotics-treated) normal, and cystic fibrosis human bronchial epithelia (HBE), and a proliferating, single-cell type bronchial epithelial cell-line (BEAS-2B). We show that a single, short-term exposure to realistic doses of atmospherically-aged gasoline-exhaust particles impairs epithelial key-defence mechanisms, rendering it more vulnerable to subsequent hazards. We establish dose-response curves at realistic particle-concentration levels. Significant differences between cell models suggest the use of fully-differentiated HBE is most appropriate in future toxicity studies. PMID:26119831

  12. Toxicity of aged gasoline exhaust particles to normal and diseased airway epithelia

    PubMed Central

    Künzi, Lisa; Krapf, Manuel; Daher, Nancy; Dommen, Josef; Jeannet, Natalie; Schneider, Sarah; Platt, Stephen; Slowik, Jay G.; Baumlin, Nathalie; Salathe, Matthias; Prévôt, André S. H.; Kalberer, Markus; Strähl, Christof; Dümbgen, Lutz; Sioutas, Constantinos; Baltensperger, Urs; Geiser, Marianne

    2015-01-01

    Particulate matter (PM) pollution is a leading cause of premature death, particularly in those with pre-existing lung disease. A causative link between particle properties and adverse health effects remains unestablished mainly due to complex and variable physico-chemical PM parameters. Controlled laboratory experiments are required. Generating atmospherically realistic aerosols and performing cell-exposure studies at relevant particle-doses are challenging. Here we examine gasoline-exhaust particle toxicity from a Euro-5 passenger car in a uniquely realistic exposure scenario, combining a smog chamber simulating atmospheric ageing, an aerosol enrichment system varying particle number concentration independent of particle chemistry, and an aerosol deposition chamber physiologically delivering particles on air-liquid interface (ALI) cultures reproducing normal and susceptible health status. Gasoline-exhaust is an important PM source with largely unknown health effects. We investigated acute responses of fully-differentiated normal, distressed (antibiotics-treated) normal, and cystic fibrosis human bronchial epithelia (HBE), and a proliferating, single-cell type bronchial epithelial cell-line (BEAS-2B). We show that a single, short-term exposure to realistic doses of atmospherically-aged gasoline-exhaust particles impairs epithelial key-defence mechanisms, rendering it more vulnerable to subsequent hazards. We establish dose-response curves at realistic particle-concentration levels. Significant differences between cell models suggest the use of fully-differentiated HBE is most appropriate in future toxicity studies. PMID:26119831

  13. Toxicity of aged gasoline exhaust particles to normal and diseased airway epithelia

    NASA Astrophysics Data System (ADS)

    Künzi, Lisa; Krapf, Manuel; Daher, Nancy; Dommen, Josef; Jeannet, Natalie; Schneider, Sarah; Platt, Stephen; Slowik, Jay G.; Baumlin, Nathalie; Salathe, Matthias; Prévôt, André S. H.; Kalberer, Markus; Strähl, Christof; Dümbgen, Lutz; Sioutas, Constantinos; Baltensperger, Urs; Geiser, Marianne

    2015-06-01

    Particulate matter (PM) pollution is a leading cause of premature death, particularly in those with pre-existing lung disease. A causative link between particle properties and adverse health effects remains unestablished mainly due to complex and variable physico-chemical PM parameters. Controlled laboratory experiments are required. Generating atmospherically realistic aerosols and performing cell-exposure studies at relevant particle-doses are challenging. Here we examine gasoline-exhaust particle toxicity from a Euro-5 passenger car in a uniquely realistic exposure scenario, combining a smog chamber simulating atmospheric ageing, an aerosol enrichment system varying particle number concentration independent of particle chemistry, and an aerosol deposition chamber physiologically delivering particles on air-liquid interface (ALI) cultures reproducing normal and susceptible health status. Gasoline-exhaust is an important PM source with largely unknown health effects. We investigated acute responses of fully-differentiated normal, distressed (antibiotics-treated) normal, and cystic fibrosis human bronchial epithelia (HBE), and a proliferating, single-cell type bronchial epithelial cell-line (BEAS-2B). We show that a single, short-term exposure to realistic doses of atmospherically-aged gasoline-exhaust particles impairs epithelial key-defence mechanisms, rendering it more vulnerable to subsequent hazards. We establish dose-response curves at realistic particle-concentration levels. Significant differences between cell models suggest the use of fully-differentiated HBE is most appropriate in future toxicity studies.

  14. The porcine lung as a potential model for cystic fibrosis

    PubMed Central

    Rogers, Christopher S.; Abraham, William M.; Brogden, Kim A.; Engelhardt, John F.; Fisher, John T.; McCray, Paul B.; McLennan, Geoffrey; Meyerholz, David K.; Namati, Eman; Ostedgaard, Lynda S.; Prather, Randall S.; Sabater, Juan R.; Stoltz, David Anthony; Zabner, Joseph; Welsh, Michael J.

    2008-01-01

    Airway disease currently causes most of the morbidity and mortality in patients with cystic fibrosis (CF). However, understanding the pathogenesis of CF lung disease and developing novel therapeutic strategies have been hampered by the limitations of current models. Although the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) has been targeted in mice, CF mice fail to develop lung or pancreatic disease like that in humans. In many respects, the anatomy, biochemistry, physiology, size, and genetics of pigs resemble those of humans. Thus pigs with a targeted CFTR gene might provide a good model for CF. Here, we review aspects of porcine airways and lung that are relevant to CF. PMID:18487356

  15. The porcine lung as a potential model for cystic fibrosis.

    PubMed

    Rogers, Christopher S; Abraham, William M; Brogden, Kim A; Engelhardt, John F; Fisher, John T; McCray, Paul B; McLennan, Geoffrey; Meyerholz, David K; Namati, Eman; Ostedgaard, Lynda S; Prather, Randall S; Sabater, Juan R; Stoltz, David Anthony; Zabner, Joseph; Welsh, Michael J

    2008-08-01

    Airway disease currently causes most of the morbidity and mortality in patients with cystic fibrosis (CF). However, understanding the pathogenesis of CF lung disease and developing novel therapeutic strategies have been hampered by the limitations of current models. Although the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) has been targeted in mice, CF mice fail to develop lung or pancreatic disease like that in humans. In many respects, the anatomy, biochemistry, physiology, size, and genetics of pigs resemble those of humans. Thus pigs with a targeted CFTR gene might provide a good model for CF. Here, we review aspects of porcine airways and lung that are relevant to CF. PMID:18487356

  16. Computational Models of Ventilator Induced Lung Injury and Surfactant Dysfunction

    PubMed Central

    Bates, Jason H.T.; Smith, Bradford J.; Allen, Gilman B.

    2014-01-01

    Managing acute respiratory distress syndrome (ARDS) invariably involves the administration of mechanical ventilation, the challenge being to avoid the iatrogenic sequellum known as ventilator-induced lung injury (VILI). Devising individualized ventilation strategies in ARDS requires that patient-specific lung physiology be taken into account, and this is greatly aided by the use of computational models of lung mechanical function that can be matched to physiological measurements made in a given patient. In this review, we discuss recent models that have the potential to serve as the basis for devising minimally injurious modes of mechanical ventilation in ARDS patients. PMID:26904138

  17. Animal models of beryllium-induced lung disease

    SciTech Connect

    Finch, G.L.; Hoover, M.D.; Hahn, F.F.

    1996-10-01

    The Inhalation Toxicology Research Institute (ITRI) is conducting research to improve the understanding of chronic beryllium disease (CBD) and beryllium-induced lung cancer. Initial animal studies examined beagle dogs that inhaled BeO calcined at either 500 or 1000{degrees}C. At similar lung burdens, the 500{degrees}C BeO induced more severe and extensive granulomatous pneumonia, lymphocytic infiltration into the lung, and positive Be-specific lymphocyte proliferative responses in vitro than the 1000{degrees}C BeO. However, the progressive nature of human CBD was not duplicated. More recently, Strains A/J and C3H/HeJ mice were exposed to Be metal by inhalation. This produced a marked granulomatous pneumonia, diffuse infiltrates, and multifocal aggregates of interstitial lymphocytes with a pronounced T helper component and pulmonary in situ lymphocyte proliferation. With respect to lung cancer, at a mean lung burden as low as 17 pg Be/g lung, inhaled Be metal induced benign and/or malignant lung tumors in over 50% of male and female F344 rats surviving {ge}1 year on study. Substantial tumor multiplicity was found, but K-ras and p53 gene mutations were virtually absent. In mice, however, a lung burden of approximately 60 {mu}g ({approximately}300 {mu}g Be/g lung) caused only a slight increase in crude lung tumor incidence and multiplicity over controls in strain A/J mice and no elevated incidence in strain C3H mice. Taken together, this research program constitutes a coordinated effort to understand beryllium-induced lung disease in experimental animal models. 47 refs., 1 fig., 3 tabs.

  18. On a PCA-based lung motion model

    NASA Astrophysics Data System (ADS)

    Li, Ruijiang; Lewis, John H.; Jia, Xun; Zhao, Tianyu; Liu, Weifeng; Wuenschel, Sara; Lamb, James; Yang, Deshan; Low, Daniel A.; Jiang, Steve B.

    2011-09-01

    Respiration-induced organ motion is one of the major uncertainties in lung cancer radiotherapy and is crucial to be able to accurately model the lung motion. Most work so far has focused on the study of the motion of a single point (usually the tumor center of mass), and much less work has been done to model the motion of the entire lung. Inspired by the work of Zhang et al (2007 Med. Phys. 34 4772-81), we believe that the spatiotemporal relationship of the entire lung motion can be accurately modeled based on principle component analysis (PCA) and then a sparse subset of the entire lung, such as an implanted marker, can be used to drive the motion of the entire lung (including the tumor). The goal of this work is twofold. First, we aim to understand the underlying reason why PCA is effective for modeling lung motion and find the optimal number of PCA coefficients for accurate lung motion modeling. We attempt to address the above important problems both in a theoretical framework and in the context of real clinical data. Second, we propose a new method to derive the entire lung motion using a single internal marker based on the PCA model. The main results of this work are as follows. We derived an important property which reveals the implicit regularization imposed by the PCA model. We then studied the model using two mathematical respiratory phantoms and 11 clinical 4DCT scans for eight lung cancer patients. For the mathematical phantoms with cosine and an even power (2n) of cosine motion, we proved that 2 and 2n PCA coefficients and eigenvectors will completely represent the lung motion, respectively. Moreover, for the cosine phantom, we derived the equivalence conditions for the PCA motion model and the physiological 5D lung motion model (Low et al 2005 Int. J. Radiat. Oncol. Biol. Phys. 63 921-9). For the clinical 4DCT data, we demonstrated the modeling power and generalization performance of the PCA model. The average 3D modeling error using PCA was within 1

  19. A biomechanical model of pendelluft induced lung injury.

    PubMed

    Alzahrany, Mohammed; Banerjee, Arindam

    2015-07-16

    Lung ventilation using high frequency oscillatory techniques have been documented to attain adequate gas exchange through various gas transport mechanisms. Among them, the pendelluft flow is considered one of the most crucial mechanisms. In this work, we computationally investigate the induction of abnormal mechanical stresses and a regionally trapped volume of gas due to pendelluft flow. Large eddy simulation was used to model the turbulence in an upper tracheobronchial lung geometry that was derived from CT scans. The pendelluft flow was captured by modeling physiological boundary conditions at the truncated level of the lung model that is sensitive to the coupled resistance and compliance of individual patients. The flow-volume and volume-pressure loops are characterized by irregular shapes and suggest abnormal regional lung ventilation. Incomplete loops were observed indicating gas trapping in these regions signifying a potential for local injury due to incomplete ventilation from a residual volume build-up at the end of the expiration phase. In addition, the gas exchange between units was observed to create a velocity gradient causing a region of high wall shear stress surrounding the carina ridges. The recurrence of the pendelluft flow could cause a rupture to the lung epithelium layer. The trapped gas and wall shear stress were observed to amplify with increasing compliance asymmetry and ventilator operating frequency. In general, despite the significant contribution of the pendelluft flow to the gas exchange augmentation there exists significant risks of localized lung injury, phenomena we describe as pendelluft induced lung injury or PILI. PMID:25997727

  20. Mooney-Rivlin biomechanical modeling of lung with Inhomogeneous material.

    PubMed

    Nasehi Tehrani, J; Wang, J

    2015-01-01

    In this study, the Mooney-Rivlin material with hyperelastic strain energy was proposed for biomechanical modeling of the lung. We modeled the lung as an inhomogeneous Mooney-Rivlin material with uncoupled deviatoric and volumetric behavior. The proposed method was evaluated on the lungs of eight lung cancer patients. For each patient, the lung was segmented from the 4D-CT images and tetrahedral volume mesh of the lung in phase 50% was created by using the adaptive mesh generation toolkit. The demons deformable registration algorithm was used to extract the displacement vector fields (DVFs). The Jacobian of the deformation gradient was calculated from DVFs, and the lung strain energy function was optimized to improve the tumor center of mass (TCM) motion simulation accuracy between respiratory phase 50% and 0%. The average TCM motion simulation error for the proposed strategy is 1.95 mm for eight patients. We observed 13% improvement in the TCM position prediction compared with the homogeneous Mooney-Rivlin modeling. PMID:26738123

  1. Computational model of OCT in lung tissue

    NASA Astrophysics Data System (ADS)

    Reed, David C.; DiMarzio, Charles A.

    2010-02-01

    Lung research may have significant impact on human health. As two examples, recovery from collapse of the alveoli and the severe post surgery declines in forced vital capacity in patients under the effects of anesthesia are both poorly understood. Optical imaging is important to lung research for its inherently high resolution. Microscopy and color imaging are fundamentals of medicine, but interior lung tissue is usually viewed either endoscopically or ex vivo, stained slices. Techniques such as confocal microscopy and optical coherence tomography (OCT) have become increasingly popular in medical imaging because of their sectioning and depth penetration. Since OCT has the ability to achieve higher depth penetration than confocal it is more widely used in lung imaging, despite the difficulty of interpreting the images due to the poor numerical aperture (NA). To understand light propagation through the highly reflective and refractive surfaces of the lung, we developed a Finite-Difference Time Domain (FDTD) simulation. FDTD solves a discrete approximation to Maxwell's equations. Initial simulations have shown that structure up to 30 - 40μm below the surface is clearly visible. Deeper structures are hard to interpret, because of light scattering, compounded by speckle associated with coherent detection. Further simulations and experimental imaging may lead to improved collection and processing of images at deeper levels.

  2. Lung lobe modeling and segmentation with individualized surface meshes

    NASA Astrophysics Data System (ADS)

    Blaffert, Thomas; Barschdorf, Hans; von Berg, Jens; Dries, Sebastian; Franz, Astrid; Klinder, Tobias; Lorenz, Cristian; Renisch, Steffen; Wiemker, Rafael

    2008-03-01

    An automated segmentation of lung lobes in thoracic CT images is of interest for various diagnostic purposes like the quantification of emphysema or the localization of tumors within the lung. Although the separating lung fissures are visible in modern multi-slice CT-scanners, their contrast in the CT-image often does not separate the lobes completely. This makes it impossible to build a reliable segmentation algorithm without additional information. Our approach uses general anatomical knowledge represented in a geometrical mesh model to construct a robust lobe segmentation, which even gives reasonable estimates of lobe volumes if fissures are not visible at all. The paper describes the generation of the lung model mesh including lobes by an average volume model, its adaptation to individual patient data using a special fissure feature image, and a performance evaluation over a test data set showing an average segmentation accuracy of 1 to 3 mm.

  3. Preclinical Murine Models for Lung Cancer: Clinical Trial Applications

    PubMed Central

    Kellar, Amelia; Egan, Cay; Morris, Don

    2015-01-01

    Murine models for the study of lung cancer have historically been the backbone of preliminary preclinical data to support early human clinical trials. However, the availability of multiple experimental systems leads to debate concerning which model, if any, is best suited for a particular therapeutic strategy. It is imperative that these models accurately predict clinical benefit of therapy. This review provides an overview of the current murine models used to study lung cancer and the advantages and limitations of each model, as well as a retrospective evaluation of the uses of each model with respect to accuracy in predicting clinical benefit of therapy. A better understanding of murine models and their uses, as well as their limitations may aid future research concerning the development and implementation of new targeted therapies and chemotherapeutic agents for lung cancer. PMID:26064932

  4. Towards a porous media model of the human lung

    NASA Astrophysics Data System (ADS)

    DeGroot, Christopher T.; Straatman, Anthony G.

    2012-05-01

    In this article, progress towards building a complete porous media model of the human lung is discussed. While the recent trend in computational fluid dynamics studies of airflow in the human lung has been to continually increase the size and detail of the airway tree under consideration, it is proposed in this work that simulating flow in the human lung as a coupled fluid-porous system is an effective method to simulate the flow in the whole lung. Under the proposed modeling paradigm, a truncated airway tree constitutes a fluid region which is coupled to a porous region that represents the remainder of the lung volume, containing small airways and alveoli. The first part of this work describes pore-level simulations conducted in an alveolated duct geometry, which are present in large quantities in the human lung, to determine its permeability. Next, volume-averaged simulations incorporating the results of the pore-level simulations and using a realistic lung geometry based on computed tomography images are discussed along with future directions for this work.

  5. Pseudomonas aeruginosa biofilm-associated homoserine lactone C12 rapidly activates apoptosis in airway epithelia

    PubMed Central

    Schwarzer, Christian; Fu, Zhu; Patanwala, Maria; Hum, Lauren; Lopez-Guzman, Mirielle; Illek, Beate; Kong, Weidong; Lynch, Susan V.; Machen, Terry E.

    2014-01-01

    Pseudomonas aeruginosa (PA) forms biofilms in lungs of cystic fibrosis CF) patients, a process regulated by quorum sensing molecules including N-(3-oxododecanoyl)-L-homoserine lactone, C12. C12 (10–100 μM) rapidly triggered events commonly associated with the intrinsic apoptotic pathway in JME (CFΔF508CFTR, nasal surface) epithelial cells: depolarization of mitochondrial (mito) membrane potential (Δψmito) and release of cytochrome C (cytoC) from mitos into cytosol and activation of caspases 3/7, 8 and 9. C12 also had novel effects on the endoplasmic reticulum (release of both Ca2+ and ER-targeted GFP and oxidized contents into the cytosol). Effects began within 5 minutes and were complete in 1–2 hrs. C12 caused similar activation of caspases and release of cytoC from mitos in Calu-3 (wtCFTR, bronchial gland) cells, showing that C12-triggered responses occurred similarly in different airway epithelial types. C12 had nearly identical effects on three key aspects of the apoptosis response (caspase 3/7, depolarization of Δψmito and reduction of redox potential in the ER) in JME and CFTR-corrected JME cells (adenoviral expression), showing that CFTR was likely not an important regulator of C12-triggered apoptosis in airway epithelia. Exposure of airway cultures to biofilms from PAO1wt caused depolarization of Δψmito and increases in Cacyto like 10–50 μM C12. In contrast, biofilms from PAO1ΔlasI (C12 deficient) had no effect, suggesting that C12 from P. aeruginosa biofilms may contribute to accumulation of apoptotic cells that cannot be cleared from CF lungs. A model to explain the effects of C12 is proposed. PMID:22233488

  6. Radioactivity and lung cancer-mathematical models of radionuclide deposition in the human lungs

    PubMed Central

    Sturm, Robert

    2011-01-01

    The human respiratory tract is regarded as pathway for radionuclides and other hazardous airborne materials to enter the body. Radioactive particles inhaled and deposited in the lungs cause an irradiation of bronchial/alveolar tissues. At the worst, this results in a malignant cellular transformation and, as a consequence of that, the development of lung cancer. In general, naturally occurring radionuclides (e.g., 222Rn, 40K) are attached to so-called carrier aerosols. The aerodynamic diameters of such radioactively labeled particles generally vary between several nanometers (ultrafine particles) and few micrometers, whereby highest particle fractions adopt sizes around 100 nm. Theoretical simulations of radioactive particle deposition in the human lungs were based on a stochastic lung geometry and a particle transport/deposition model using the random-walk algorithm. Further a polydisperse carrier aerosol (diameter: 1 nm–10 µm, ρ ≈ 1 g cm−3) with irregularly shaped particles and the effect of breathing characteristics and certain respiratory parameters on the transport of radioactive particles to bronchial/alveolar tissues were considered. As clearly shown by the results of deposition modeling, distribution patterns of radiation doses mainly depend on the size of the carrier aerosol. Ultrafine (< 10 nm) and large (> 2 µm) aerosol particles are preferentially deposited in the extrathoracic and upper bronchial region, whereas aerosol particles with intermediate size (10 nm–2 µm) may penetrate to deeper lung regions, causing an enhanced damage of the alveolar tissue by the attached radionuclides. PMID:22263097

  7. Models to teach lung sonopathology and ultrasound-guided thoracentesis.

    PubMed

    Wojtczak, Jacek A

    2014-12-01

    Lung sonography allows rapid diagnosis of lung emergencies such as pulmonary edema, hemothorax or pneumothorax. The ability to timely diagnose an intraoperative pneumothorax is an important skill for the anesthesiologist. However, lung ultrasound exams require an interpretation of not only real images but also complex acoustic artifacts such as A-lines and B-lines. Therefore, appropriate training to gain proficiency is important. Simulated environment using ultrasound phantom models allows controlled, supervised learning. We have developed hybrid models that combine dry or wet polyurethane foams, porcine rib cages and human hand simulating a rib cage. These models simulate fairly accurately pulmonary sonopathology and allow supervised teaching of lung sonography with the immediate feedback. In-vitro models can also facilitate learning of procedural skills, improving transducer and needle positioning and movement, rapid recognition of thoracic anatomy and hand - eye coordination skills. We described a new model to teach an ultrasound guided thoracentesis. This model consists of the experimenter's hand placed on top of the water-filled container with a wet foam. Metacarpal bones of the human hand simulate a rib cage and a wet foam simulates a diseased lung immersed in the pleural fluid. Positive fluid flow offers users feedback when a simulated pleural effusion is accurately assessed. PMID:26672739

  8. Influence of exercise on airway epithelia in cystic fibrosis: a review.

    PubMed

    Cholewa, Jason Michael; Paolone, Vincent J

    2012-07-01

    Regular exercise is recommended as part of cystic fibrosis (CF) physiotherapy. Exercise delays the development of pulmonary disease in CF patients; however, the cellular mechanisms responsible for these improvements are unclear. This review expands on the hypothesis that exercise improves CF pathophysiological ion dysregulation via purinergic and adrenergic pathways by describing the effects of 5' adenosine monophosphate-activated protein kinase (AMPK), atrial natriuretic peptide (ANP), and arginine-vasopressin (AVP) on CF airway epithelia. Activation of AMPK decreases Na(+) absorption, increases airway surface liquid, and reduces oxidative stress and inflammation. Plasma ANP inhibits the basolateral Na(+)/K(+)-ATPase and may therefore reduce epithelial water absorption. Airway epithelia respond to plasma AVP and secrete AVP in response to elevated bradykinin. AVP stimulates the basolateral Na(+)/K(+)/2Cl(-) exchanger, thereby increasing Cl(-) secretion, reducing Na(+) absorption, and promoting basolateral to luminal water flux. In addition, AVP may increase cilia beat frequency in airway epithelia via a Ca(2+)-dependent mechanism. This review will describe the effects of exercise on AMPK activation, ANP release, and AVP secretion; we hypothesize that the mechanical and metabolic perturbations that occur with exercise may be beneficial in preventing CF lung pathogenesis by improving airway hydration, mucociliary clearance, and reducing markers of inflammation. PMID:22297805

  9. Modeling of the Nitric Oxide Transport in the Human Lungs

    PubMed Central

    Karamaoun, Cyril; Van Muylem, Alain; Haut, Benoît

    2016-01-01

    In the human lungs, nitric oxide (NO) acts as a bronchodilatator, by relaxing the bronchial smooth muscles and is closely linked to the inflammatory status of the lungs, owing to its antimicrobial activity. Furthermore, the molar fraction of NO in the exhaled air has been shown to be higher for asthmatic patients than for healthy patients. Multiple models have been developed in order to characterize the NO dynamics in the lungs, owing to their complex structure. Indeed, direct measurements in the lungs are difficult and, therefore, these models are valuable tools to interpret experimental data. In this work, a new model of the NO transport in the human lungs is proposed. It belongs to the family of the morphological models and is based on the morphometric model of Weibel (1963). When compared to models published previously, its main new features are the layered representation of the wall of the airways and the possibility to simulate the influence of bronchoconstriction (BC) and of the presence of mucus on the NO transport in lungs. The model is based on a geometrical description of the lungs, at rest and during a respiratory cycle, coupled with transport equations, written in the layers composing an airway wall and in the lumen of the airways. First, it is checked that the model is able to reproduce experimental information available in the literature. Second, the model is used to discuss some features of the NO transport in healthy and unhealthy lungs. The simulation results are analyzed, especially when BC has occurred in the lungs. For instance, it is shown that BC can have a significant influence on the NO transport in the tissues composing an airway wall. It is also shown that the relation between BC and the molar fraction of NO in the exhaled air is complex. Indeed, BC might lead to an increase or to a decrease of this molar fraction, depending on the extent of the BC and on the possible presence of mucus. This should be confirmed experimentally and might

  10. The beetle amnion and serosa functionally interact as apposed epithelia.

    PubMed

    Hilbrant, Maarten; Horn, Thorsten; Koelzer, Stefan; Panfilio, Kristen A

    2016-01-01

    Unlike passive rupture of the human chorioamnion at birth, the insect extraembryonic (EE) tissues - the amnion and serosa - actively rupture and withdraw in late embryogenesis. Withdrawal is essential for development and has been a morphogenetic puzzle. Here, we use new fluorescent transgenic lines in the beetle Tribolium castaneum to show that the EE tissues dynamically form a basal-basal epithelial bilayer, contradicting the previous hypothesis of EE intercalation. We find that the EE tissues repeatedly detach and reattach throughout development and have distinct roles. Quantitative live imaging analyses show that the amnion initiates EE rupture in a specialized anterior-ventral cap. RNAi phenotypes demonstrate that the serosa contracts autonomously. Thus, apposition in a bilayer enables the amnion as 'initiator' to coordinate with the serosa as 'driver' to achieve withdrawal. This EE strategy may reflect evolutionary changes within the holometabolous insects and serves as a model to study interactions between developing epithelia. PMID:26824390

  11. Quantification of growth asymmetries in developing epithelia

    NASA Astrophysics Data System (ADS)

    Bittig, T.; Wartlick, O.; González-Gaitán, M.; Jülicher, F.

    2009-09-01

    Many developmental processes of multicellular organisms involve the patterning and growth of two-dimensional tissues, so called epithelia. We have quantified the growth of the wing imaginal disk, which is the precursor of the adult wing, of the fruit fly Drosophila melanogaster. We find that growth follows a simple rule with exponentially decreasing area growth rate. Anisotropies of growth can be precisely determined by comparing experimental results to a continuum theory. Growth anisotropies are to good approximation constant in space and time. They are weak in wild-type wing disks but threefold increased in GFP-Dpp disks in which the morphogen Dpp is overexpressed. Our findings indicate that morphogens such as Dpp control tissue shape via oriented cell divisions that generate anisotropic growth. in here

  12. ANATOMICAL MODELING OF MICRODOSIMETRY OF INHALED PARTICLES IN THE LUNG

    EPA Science Inventory

    Determining the dose delivered to specific sites in the lungs is a critical first step in modeling the potential toxic effects of airborne pollutants. n important recent development in estimating site specific dosimetry has been combining sophisticated analytical models to determ...

  13. Alterations of lung microbiota in a mouse model of LPS-induced lung injury

    PubMed Central

    Meng, Fanyong; Meliton, Angelo; Afonyushkin, Taras; Ulanov, Alexander; Semenyuk, Ekaterina; Latif, Omar; Tesic, Vera; Birukova, Anna A.; Birukov, Konstantin G.

    2015-01-01

    Acute lung injury (ALI) and the more severe acute respiratory distress syndrome are common responses to a variety of infectious and noninfectious insults. We used a mouse model of ALI induced by intratracheal administration of sterile bacterial wall lipopolysaccharide (LPS) to investigate the changes in innate lung microbiota and study microbial community reaction to lung inflammation and barrier dysfunction induced by endotoxin insult. One group of C57BL/6J mice received LPS via intratracheal injection (n = 6), and another received sterile water (n = 7). Bronchoalveolar lavage (BAL) was performed at 72 h after treatment. Bacterial DNA was extracted and used for qPCR and 16S rRNA gene-tag (V3–V4) sequencing (Illumina). The bacterial load in BAL from ALI mice was increased fivefold (P = 0.03). The community complexity remained unchanged (Simpson index, P = 0.7); the Shannon diversity index indicated the increase of community evenness in response to ALI (P = 0.07). Principal coordinate analysis and analysis of similarity (ANOSIM) test (P = 0.005) revealed a significant difference between microbiota of control and ALI groups. Bacteria from families Xanthomonadaceae and Brucellaceae increased their abundance in the ALI group as determined by Metastats test (P < 0.02). In concordance with the 16s-tag data, Stenotrohomonas maltophilia (Xanthomonadaceae) and Ochrobactrum anthropi (Brucellaceae) were isolated from lungs of mice from both groups. Metabolic profiling of BAL detected the presence of bacterial substrates suitable for both isolates. Additionally, microbiota from LPS-treated mice intensified IL-6-induced lung inflammation in naive mice. We conclude that the morbid transformation of ALI microbiota was attributed to the set of inborn opportunistic pathogens thriving in the environment of inflamed lung, rather than the external infectious agents. PMID:25957290

  14. Mouse Model for ROS1-Rearranged Lung Cancer

    PubMed Central

    Takahashi, Hiroyuki; Nakamura, Hiromi; Hama, Natsuko; Kohno, Takashi; Tsuta, Koji; Yoshida, Akihiko; Asamura, Hisao; Mutoh, Michihiro; Hosoda, Fumie; Tsuda, Hitoshi; Shibata, Tatsuhiro

    2013-01-01

    Genetic rearrangement of the ROS1 receptor tyrosine kinase was recently identified as a distinct molecular signature for human non-small cell lung cancer (NSCLC). However, direct evidence of lung carcinogenesis induced by ROS1 fusion genes remains to be verified. The present study shows that EZR-ROS1 plays an essential role in the oncogenesis of NSCLC harboring the fusion gene. EZR-ROS1 was identified in four female patients of lung adenocarcinoma. Three of them were never smokers. Interstitial deletion of 6q22–q25 resulted in gene fusion. Expression of the fusion kinase in NIH3T3 cells induced anchorage-independent growth in vitro, and subcutaneous tumors in nude mice. This transforming ability was attributable to its kinase activity. The ALK/MET/ROS1 kinase inhibitor, crizotinib, suppressed fusion-induced anchorage-independent growth of NIH3T3 cells. Most importantly, established transgenic mouse lines specifically expressing EZR-ROS1 in lung alveolar epithelial cells developed multiple adenocarcinoma nodules in both lungs at an early age. These data suggest that the EZR-ROS1 is a pivotal oncogene in human NSCLC, and that this animal model could be valuable for exploring therapeutic agents against ROS1-rearranged lung cancer. PMID:23418494

  15. A protocol for a lung neovascularization model in rodents

    PubMed Central

    Jones, Rosemary C; Capen, Diane E; Petersen, Bodil; Jain, Rakesh K; Duda, Dan G

    2009-01-01

    By providing insight into the cellular events of vascular injury and repair, experimental model systems seek to promote timely therapeutic strategies for human disease. The goal of many current studies of neovascularization is to identify cells critical to the process and their role in vascular channel assembly. We propose here a protocol to analyze, in an in vivo rodent model, vessel and capillary remodeling (reorganization and growth) in the injured lung. Sequential analyses of stages in the assembly of vascular structures, and of relevant cell types, provide further opportunities to study the molecular and cellular determinants of lung neovascularization. PMID:18323809

  16. The 34th Annual Fall Meeting of the American Physiological Society and the International Conference on Hydrogen Ion Transport in Epithelia.

    ERIC Educational Resources Information Center

    Physiologist, 1983

    1983-01-01

    Provided are abstracts of papers presented at the annual American Physiological Society meeting and International Conference on Hydrogen Ion Transport in Epithelia. Papers are grouped by such topic areas as lung fluid balance, renal cardiovascular integration, smooth muscle physiology, neuroendocrines (pituitary), exercise physiology, mechanics of…

  17. Epithelia migration: A spatiotemporal interplay between contraction and adhesion

    PubMed Central

    Rubinstein, Boris; Pinto, Inês Mendes

    2015-01-01

    Epithelial tissues represent 60% of the cells that form the human body and where more than 90% of all cancers derived. Epithelia transformation and migration involve altered cell contractile mechanics powered by an actomyosin-based cytoskeleton and influenced by cell-cell and cell-extracellular matrix interactions. A balance between contractile and adhesive forces regulates a large number of cellular and tissue properties crucial for epithelia migration and tumorigenesis. In this review, the forces driving normal epithelia transformation into highly motile and invasive cells and tissues will be discussed. PMID:26176587

  18. Interdependent regional lung emptying during forced expiration: a transistor model.

    PubMed

    Solway, J; Fredberg, J J; Ingram, R H; Pedersen, O F; Drazen, J M

    1987-05-01

    We recognized similarities between isovolume pressure-flow curves of the lung and emitter-collector voltage-current characteristics of bipolar transistors, and used this analogy to model expiratory flow limitation in a two-generation branching network with parallel nonhomogeneity. In this model, each of two bronchi empty parenchymal compliances through a common trachea, and each branch includes resistances upstream and downstream of a flow-limiting site. Properties of each airway are specified independently, allowing simulation of differences between the tracheal and bronchial generations and between the parallel bronchial paths. Simulations of four types of parallel asymmetry were performed: unilateral peripheral bronchoconstriction; unilateral central bronchoconstriction; asymmetric redistribution of parenchymal compliance; and unilateral alteration of the bronchial area-transmural pressure characteristic. Our results indicate that multiple axial choke points can exist simultaneously in a symmetric lung when large airway opening-pleural pressure gradients exist; despite severe nonhomogeneity of regional lung emptying, flow interdependence among parallel branches tends to maintain a near normal configuration of the overall maximal expiratory flow-volume (MEFV) curve throughout a large fraction of the vital capacity; and sudden changes of slope of the MEFV curve ("knees" or "bumps") may reflect choking in one branch in a nonuniform lung, but need not be obvious even when severe heterogeneity of lung emptying exists. PMID:3597273

  19. Incorporation of adenovirus in calcium phosphate precipitates enhances gene transfer to airway epithelia in vitro and in vivo.

    PubMed Central

    Fasbender, A; Lee, J H; Walters, R W; Moninger, T O; Zabner, J; Welsh, M J

    1998-01-01

    Adenovirus (Ad)-mediated gene transfer to airway epithelia is inefficient because the apical membrane lacks the receptor activity to bind adenovirus fiber protein. Calcium phosphate (CaPi) precipitates have been used to deliver plasmid DNA to cultured cell lines. However, such precipitates are not effective in many primary cultures or in vivo. Here we show that incorporating recombinant adenovirus into a CaPi coprecipitate markedly enhances transgene expression in cells that are resistant to adenovirus infection. Enhancement requires that the virus be contained in the precipitate and viral proteins are required to increase expression. Ad: CaPi coprecipitates increase gene transfer by increasing fiber-independent binding of virus to cells. With differentiated cystic fibrosis (CF) airway epithelia in vitro, a 20-min application of Ad:CaPi coprecipitates that encode CF transmembrane conductance regulator produced as much CF transmembrane conductance regulator Cl- current as a 24-h application of adenovirus alone. We found that Ad:CaPi coprecipitates also increased transgene expression in mouse lung in vivo; importantly, expression was particularly prominent in airway epithelia. These results suggest a new mechanism for gene transfer that may be applicable to a number of different gene transfer applications and could be of value in gene transfer to CF airway epithelia in vivo. PMID:9649572

  20. Advances in Cell and Gene-based Therapies for Cystic Fibrosis Lung Disease

    PubMed Central

    Oakland, Mayumi; Sinn, Patrick L; McCray Jr, Paul B

    2012-01-01

    Cystic fibrosis (CF) is a disease characterized by airway infection, inflammation, remodeling, and obstruction that gradually destroy the lungs. Direct delivery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene to airway epithelia may offer advantages, as the tissue is accessible for topical delivery of vectors. Yet, physical and host immune barriers in the lung present challenges for successful gene transfer to the respiratory tract. Advances in gene transfer approaches, tissue engineering, and novel animal models are generating excitement within the CF research field. This review discusses current challenges and advancements in viral and nonviral vectors, cell-based therapies, and CF animal models. PMID:22371844

  1. Advances in cell and gene-based therapies for cystic fibrosis lung disease.

    PubMed

    Oakland, Mayumi; Sinn, Patrick L; McCray, Paul B

    2012-06-01

    Cystic fibrosis (CF) is a disease characterized by airway infection, inflammation, remodeling, and obstruction that gradually destroy the lungs. Direct delivery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene to airway epithelia may offer advantages, as the tissue is accessible for topical delivery of vectors. Yet, physical and host immune barriers in the lung present challenges for successful gene transfer to the respiratory tract. Advances in gene transfer approaches, tissue engineering, and novel animal models are generating excitement within the CF research field. This review discusses current challenges and advancements in viral and nonviral vectors, cell-based therapies, and CF animal models. PMID:22371844

  2. Modeling of weak blast wave propagation in the lung.

    PubMed

    D'yachenko, A I; Manyuhina, O V

    2006-01-01

    Blast injuries of the lung are the most life-threatening after an explosion. The choice of physical parameters responsible for trauma is important to understand its mechanism. We developed a one-dimensional linear model of an elastic wave propagation in foam-like pulmonary parenchyma to identify the possible cause of edema due to the impact load. The model demonstrates different injury localizations for free and rigid boundary conditions. The following parameters were considered: strain, velocity, pressure in the medium and stresses in structural elements, energy dissipation, parameter of viscous criterion. Maximum underpressure is the most suitable wave parameter to be the criterion for edema formation in a rabbit lung. We supposed that observed scattering of experimental data on edema severity is induced by the physiological variety of rabbit lungs. The criterion and the model explain this scattering. The model outlines the demands for experimental data to make an unambiguous choice of physical parameters responsible for lung trauma due to impact load. PMID:16214154

  3. Mathematical model of the human lungs during phonation

    NASA Astrophysics Data System (ADS)

    Meshcheryakov, R. V.

    2012-08-01

    Modeling of the human lungs during phonation is considered. The main relationships during physiological phonation process and air passage through vocal folds are established. Results of investigation are presented for statements of various types corresponding to different intonation patterns of the statement.

  4. RECONSTRUCTION OF HUMAN LUNG MORPHOLOGY MODELS FROM MAGNETIC RESONANCE IMAGES

    EPA Science Inventory


    Reconstruction of Human Lung Morphology Models from Magnetic Resonance Images
    T. B. Martonen (Experimental Toxicology Division, U.S. EPA, Research Triangle Park, NC 27709) and K. K. Isaacs (School of Public Health, University of North Carolina, Chapel Hill, NC 27514)

  5. Modeling Air Flow in the Lungs during In-exsufflation

    NASA Astrophysics Data System (ADS)

    Bukiet, Bruce; Chaudhry, Hans; Kirshblum, Steven; Bach, John

    2003-11-01

    Patients with weak respiratory systems experience build-up of fluid in the lungs. This can lead to infection and hospitalization. Although endotracheal suctioning can help relieve this problem, it is invasive and uncomfortable. Patients prefer the non-invasive mechanical in-exsufflation technique. In this talk, we describe these techniques for easing the problem of mucus build-up and present ideas for mathematical and computational modeling of the flow in the branches of the lungs during mechanical in-exsufflation. The implications of the results of the computations on the safety of the technique and on patient treatment are also discussed.

  6. An ex vivo human lung model for ultrasound-guided high-intensity focused ultrasound therapy using lung flooding.

    PubMed

    Wolfram, Frank; Reichenbach, Jürgen R; Lesser, Thomas G

    2014-03-01

    The usability of an ex vivo human lung model for ablation of lung cancer tissue with high-intensity focused ultrasound (HIFU) is described. Lung lobes were flooded with saline, with no gas remaining after complete atelectasis. The tumor was delineated sono-morphologically. Speed of sound, tissue density and ultrasound attenuation were measured for flooded lung and different pulmonary cancer tissues. The acoustic impedance of lung cancer tissue (1.6-1.9 mega-Rayleighs) was higher than that of water, as was its attenuation coefficient (0.31-0.44 dB/cm/MHz) compared with that of the flooded lung (0.12 dB/cm/MHz). After application of HIFU, the temperature in centrally located lung cancer surrounded by the flooded lung increased as high as 80°C, which is sufficient for treatment. On the basis of these preliminary results, ultrasound-guided HIFU ablation of lung cancer, by lung flooding with saline, appears feasible and should be explored in future clinical studies. PMID:24412177

  7. A poroelastic model coupled to a fluid network with applications in lung modelling.

    PubMed

    Berger, Lorenz; Bordas, Rafel; Burrowes, Kelly; Grau, Vicente; Tavener, Simon; Kay, David

    2016-01-01

    We develop a lung ventilation model based on a continuum poroelastic representation of lung parenchyma that is strongly coupled to a pipe network representation of the airway tree. The continuous system of equations is discretized using a low-order stabilised finite element method. The framework is applied to a realistic lung anatomical model derived from computed tomography data and an artificially generated airway tree to model the conducting airway region. Numerical simulations produce physiologically realistic solutions and demonstrate the effect of airway constriction and reduced tissue elasticity on ventilation, tissue stress and alveolar pressure distribution. The key advantage of the model is the ability to provide insight into the mutual dependence between ventilation and deformation. This is essential when studying lung diseases, such as chronic obstructive pulmonary disease and pulmonary fibrosis. Thus the model can be used to form a better understanding of integrated lung mechanics in both the healthy and diseased states. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26100614

  8. Pancreatitis-induced acute lung injury. An ARDS model.

    PubMed Central

    Guice, K S; Oldham, K T; Johnson, K J; Kunkel, R G; Morganroth, M L; Ward, P A

    1988-01-01

    Cerulein-induced acute pancreatitis in rats is associated with acute lung injury characterized by increased pulmonary microvascular permeability, increased wet lung weights, and histologic features of alveolar capillary endothelial cell and pulmonary parenchymal injury. The alveolar capillary permeability index is increased 1.8-fold after a 3-hour injury (0.30 to 0.54, p less than 0.05). Gravimetric analysis shows a similar 1.5-fold increase in wet lung weights at 3 hours (0.35% vs. 0.51% of total body weight, p less than 0.05). Histologic features assessed by quantitative morphometric analysis include significant intra-alveolar hemorrhage (0.57 +/- 0.08 vs. 0.12 +/- 0.02 RBC/alveolus at 6 hours, p less than 0.001); endothelial cell disruption (28.11% vs. 4.3%, p less than 0.001); and marked, early neutrophil infiltration (7.45 +/- 0.53 vs. 0.83 +/- 0.18 PMN/hpf at 3 hours, p less than 0.001). The cerulein peptide itself, a cholecystokinin (CCK) analog, is naturally occurring and is not toxic and in several in vitro settings including exposure to pulmonary artery endothelial cells, Type II epithelial cells, and an ex vivo perfused lung preparation. The occurrence of this ARDS-like acute lung injury with acute pancreatitis provides an excellent experimental model to investigate mechanisms and mediators involved in the pathogenesis of ARDS. Images Fig. 1. PMID:3389946

  9. Pancreatitis-induced acute lung injury. An ARDS model.

    PubMed

    Guice, K S; Oldham, K T; Johnson, K J; Kunkel, R G; Morganroth, M L; Ward, P A

    1988-07-01

    Cerulein-induced acute pancreatitis in rats is associated with acute lung injury characterized by increased pulmonary microvascular permeability, increased wet lung weights, and histologic features of alveolar capillary endothelial cell and pulmonary parenchymal injury. The alveolar capillary permeability index is increased 1.8-fold after a 3-hour injury (0.30 to 0.54, p less than 0.05). Gravimetric analysis shows a similar 1.5-fold increase in wet lung weights at 3 hours (0.35% vs. 0.51% of total body weight, p less than 0.05). Histologic features assessed by quantitative morphometric analysis include significant intra-alveolar hemorrhage (0.57 +/- 0.08 vs. 0.12 +/- 0.02 RBC/alveolus at 6 hours, p less than 0.001); endothelial cell disruption (28.11% vs. 4.3%, p less than 0.001); and marked, early neutrophil infiltration (7.45 +/- 0.53 vs. 0.83 +/- 0.18 PMN/hpf at 3 hours, p less than 0.001). The cerulein peptide itself, a cholecystokinin (CCK) analog, is naturally occurring and is not toxic and in several in vitro settings including exposure to pulmonary artery endothelial cells, Type II epithelial cells, and an ex vivo perfused lung preparation. The occurrence of this ARDS-like acute lung injury with acute pancreatitis provides an excellent experimental model to investigate mechanisms and mediators involved in the pathogenesis of ARDS. PMID:3389946

  10. Parallel Computation of Airflow in the Human Lung Model

    NASA Astrophysics Data System (ADS)

    Lee, Taehun; Tawhai, Merryn; Hoffman, Eric. A.

    2005-11-01

    Parallel computations of airflow in the human lung based on domain decomposition are performed. The realistic lung model is segmented and reconstructed from CT images as part of an effort to build a normative atlas (NIH HL-04368) documenting airway geometry over 4 decades of age in healthy and disease-state adult humans. Because of the large number of the airway generation and the sheer complexity of the geometry, massively parallel computation of pulmonary airflow is carried out. We present the parallel algorithm implemented in the custom-developed characteristic-Galerkin finite element method, evaluate the speed-up and scalability of the scheme, and estimate the computing resources needed to simulate the airflow in the conducting airways of the human lungs. It is found that the special tree-like geometry enables the inter-processor communications to occur among only three or four processors for optimal parallelization irrespective of the number of processors involved in the computation.

  11. Toll-Like Receptor 4 Engagement Mediates Prolyl Endopeptidase Release from Airway Epithelia via Exosomes.

    PubMed

    Szul, Tomasz; Bratcher, Preston E; Fraser, Kyle B; Kong, Michele; Tirouvanziam, Rabindra; Ingersoll, Sarah; Sztul, Elizabeth; Rangarajan, Sunil; Blalock, J Edwin; Xu, Xin; Gaggar, Amit

    2016-03-01

    Proteases are important regulators of pulmonary remodeling and airway inflammation. Recently, we have characterized the enzyme prolyl endopeptidase (PE), a serine peptidase, as a critical protease in the generation of the neutrophil chemoattractant tripeptide Pro-Gly-Pro (PGP) from collagen. However, PE has been characterized as a cytosolic enzyme, and the mechanism mediating PE release extracellularly remains unknown. We examined the role of exosomes derived from airway epithelia as a mechanism for PE release and the potential extracellular signals that regulate the release of these exosomes. We demonstrate a specific regulatory pathway of exosome release from airway epithelia and identify PE as novel exosome cargo. LPS stimulation of airway epithelial cells induces release of PE-containing exosomes, which is significantly attenuated by small interfering RNA depletion of Toll-like receptor 4 (TLR4). These differences were recapitulated upon intratracheal LPS administration in mice competent versus deficient for TLR4 signaling. Finally, sputum samples from subjects with cystic fibrosis colonized with Pseudomonas aeruginosa demonstrate elevated exosome content and increased PE levels. This TLR4-based mechanism highlights the first report of nonstochastic release of exosomes in the lung and couples TLR4 activation with matrikine generation. The increased quantity of these proteolytic exosomes in the airways of subjects with chronic lung disease highlights a new mechanism of injury and inflammation in the pathogenesis of pulmonary disorders. PMID:26222144

  12. Effective Rat Lung Tumor Model for Stereotactic Body Radiation Therapy.

    PubMed

    Zhang, Zhang; Wodzak, Michelle; Belzile, Olivier; Zhou, Heling; Sishc, Brock; Yan, Hao; Stojadinovic, Strahinja; Mason, Ralph P; Brekken, Rolf A; Chopra, Rajiv; Story, Michael D; Timmerman, Robert; Saha, Debabrata

    2016-06-01

    Stereotactic body radiation therapy (SBRT) has found an important role in the treatment of patients with non-small cell lung cancer, demonstrating improvements in dose distribution and even tumor cure rates, particularly for early-stage disease. Despite its emerging clinical efficacy, SBRT has primarily evolved due to advances in medical imaging and more accurate dose delivery, leaving a void in knowledge of the fundamental biological mechanisms underlying its activity. Thus, there is a critical need for the development of orthotropic animal models to further probe the biology associated with high-dose-per-fraction treatment typical of SBRT. We report here on an improved surgically based methodology for generating solitary intrapulmonary nodule tumors, which can be treated with simulated SBRT using the X-RAD 225Cx small animal irradiator and Small Animal RadioTherapy (SmART) Plan treatment system. Over 90% of rats developed solitary tumors in the right lung. Furthermore, the tumor response to radiation was monitored noninvasively via bioluminescence imaging (BLI), and complete ablation of tumor growth was achieved with 36 Gy (3 fractions of 12 Gy each). We report a reproducible, orthotopic, clinically relevant lung tumor model, which better mimics patient treatment regimens. This system can be utilized to further explore the underlying biological mechanisms relevant to SBRT and high-dose-per-fraction radiation exposure and to provide a useful model to explore the efficacy of radiation modifiers in the treatment of non-small cell lung cancer. PMID:27223828

  13. A method for avoiding overlap of left and right lungs in shape model guided segmentation of lungs in CT volumes

    PubMed Central

    Gill, Gurman; Bauer, Christian; Beichel, Reinhard R.

    2014-01-01

    Purpose: The automated correct segmentation of left and right lungs is a nontrivial problem, because the tissue layer between both lungs can be quite thin. In the case of lung segmentation with left and right lung models, overlapping segmentations can occur. In this paper, the authors address this issue and propose a solution for a model-based lung segmentation method. Methods: The thin tissue layer between left and right lungs is detected by means of a classification approach and utilized to selectively modify the cost function of the lung segmentation method. The approach was evaluated on a diverse set of 212 CT scans of normal and diseased lungs. Performance was assessed by utilizing an independent reference standard and by means of comparison to the standard segmentation method without overlap avoidance. Results: For cases where the standard approach produced overlapping segmentations, the proposed method significantly (p = 1.65 × 10−9) reduced the overlap by 97.13% on average (median: 99.96%). In addition, segmentation accuracy assessed with the Dice coefficient showed a statistically significant improvement (p = 7.5 × 10−5) and was 0.9845 ± 0.0111. For cases where the standard approach did not produce an overlap, performance of the proposed method was not found to be significantly different. Conclusions: The proposed method improves the quality of the lung segmentations, which is important for subsequent quantitative analysis steps. PMID:25281960

  14. Automated 3-D Segmentation of Lungs With Lung Cancer in CT Data Using a Novel Robust Active Shape Model Approach

    PubMed Central

    Sun, Shanhui; Bauer, Christian; Beichel, Reinhard

    2013-01-01

    Segmentation of lungs with (large) lung cancer regions is a nontrivial problem. We present a new fully automated approach for segmentation of lungs with such high-density pathologies. Our method consists of two main processing steps. First, a novel robust active shape model (RASM) matching method is utilized to roughly segment the outline of the lungs. The initial position of the RASM is found by means of a rib cage detection method. Second, an optimal surface finding approach is utilized to further adapt the initial segmentation result to the lung. Left and right lungs are segmented individually. An evaluation on 30 data sets with 40 abnormal (lung cancer) and 20 normal left/right lungs resulted in an average Dice coefficient of 0.975 ± 0.006 and a mean absolute surface distance error of 0.84 ± 0.23 mm, respectively. Experiments on the same 30 data sets showed that our methods delivered statistically significant better segmentation results, compared to two commercially available lung segmentation approaches. In addition, our RASM approach is generally applicable and suitable for large shape models. PMID:21997248

  15. HIF1A Reduces Acute Lung Injury by Optimizing Carbohydrate Metabolism in the Alveolar Epithelium

    PubMed Central

    Bonney, Megan; Packard, Thomas; Han, Jun; Borchers, Christoph H.; Mariani, Thomas J.; Kominsky, Douglas J.; Mittelbronn, Michel; Eltzschig, Holger K.

    2013-01-01

    Background While acute lung injury (ALI) contributes significantly to critical illness, it resolves spontaneously in many instances. The majority of patients experiencing ALI require mechanical ventilation. Therefore, we hypothesized that mechanical ventilation and concomitant stretch-exposure of pulmonary epithelia could activate endogenous pathways important in lung protection. Methods and Findings To examine transcriptional responses during ALI, we exposed pulmonary epithelia to cyclic mechanical stretch conditions—an in vitro model resembling mechanical ventilation. A genome-wide screen revealed a transcriptional response similar to hypoxia signaling. Surprisingly, we found that stabilization of hypoxia-inducible factor 1A (HIF1A) during stretch conditions in vitro or during ventilator-induced ALI in vivo occurs under normoxic conditions. Extension of these findings identified a functional role for stretch-induced inhibition of succinate dehydrogenase (SDH) in mediating normoxic HIF1A stabilization, concomitant increases in glycolytic capacity, and improved tricarboxylic acid (TCA) cycle function. Pharmacologic studies with HIF activator or inhibitor treatment implicated HIF1A-stabilization in attenuating pulmonary edema and lung inflammation during ALI in vivo. Systematic deletion of HIF1A in the lungs, endothelia, myeloid cells, or pulmonary epithelia linked these findings to alveolar-epithelial HIF1A. In vivo analysis of 13C-glucose metabolites utilizing liquid-chromatography tandem mass-spectrometry demonstrated that increases in glycolytic capacity, improvement of mitochondrial respiration, and concomitant attenuation of lung inflammation during ALI were specific for alveolar-epithelial expressed HIF1A. Conclusions These studies reveal a surprising role for HIF1A in lung protection during ALI, where normoxic HIF1A stabilization and HIF-dependent control of alveolar-epithelial glucose metabolism function as an endogenous feedback loop to dampen lung

  16. Computational modeling of the obstructive lung diseases asthma and COPD.

    PubMed

    Burrowes, Kelly Suzanne; Doel, Tom; Brightling, Chris

    2014-11-28

    Asthma and chronic obstructive pulmonary disease (COPD) are characterized by airway obstruction and airflow imitation and pose a huge burden to society. These obstructive lung diseases impact the lung physiology across multiple biological scales. Environmental stimuli are introduced via inhalation at the organ scale, and consequently impact upon the tissue, cellular and sub-cellular scale by triggering signaling pathways. These changes are propagated upwards to the organ level again and vice versa. In order to understand the pathophysiology behind these diseases we need to integrate and understand changes occurring across these scales and this is the driving force for multiscale computational modeling. There is an urgent need for improved diagnosis and assessment of obstructive lung diseases. Standard clinical measures are based on global function tests which ignore the highly heterogeneous regional changes that are characteristic of obstructive lung disease pathophysiology. Advances in scanning technology such as hyperpolarized gas MRI has led to new regional measurements of ventilation, perfusion and gas diffusion in the lungs, while new image processing techniques allow these measures to be combined with information from structural imaging such as Computed Tomography (CT). However, it is not yet known how to derive clinical measures for obstructive diseases from this wealth of new data. Computational modeling offers a powerful approach for investigating this relationship between imaging measurements and disease severity, and understanding the effects of different disease subtypes, which is key to developing improved diagnostic methods. Gaining an understanding of a system as complex as the respiratory system is difficult if not impossible via experimental methods alone. Computational models offer a complementary method to unravel the structure-function relationships occurring within a multiscale, multiphysics system such as this. Here we review the currentstate

  17. Computational modeling of the obstructive lung diseases asthma and COPD

    PubMed Central

    2014-01-01

    Asthma and chronic obstructive pulmonary disease (COPD) are characterized by airway obstruction and airflow limitation and pose a huge burden to society. These obstructive lung diseases impact the lung physiology across multiple biological scales. Environmental stimuli are introduced via inhalation at the organ scale, and consequently impact upon the tissue, cellular and sub-cellular scale by triggering signaling pathways. These changes are propagated upwards to the organ level again and vice versa. In order to understand the pathophysiology behind these diseases we need to integrate and understand changes occurring across these scales and this is the driving force for multiscale computational modeling. There is an urgent need for improved diagnosis and assessment of obstructive lung diseases. Standard clinical measures are based on global function tests which ignore the highly heterogeneous regional changes that are characteristic of obstructive lung disease pathophysiology. Advances in scanning technology such as hyperpolarized gas MRI has led to new regional measurements of ventilation, perfusion and gas diffusion in the lungs, while new image processing techniques allow these measures to be combined with information from structural imaging such as Computed Tomography (CT). However, it is not yet known how to derive clinical measures for obstructive diseases from this wealth of new data. Computational modeling offers a powerful approach for investigating this relationship between imaging measurements and disease severity, and understanding the effects of different disease subtypes, which is key to developing improved diagnostic methods. Gaining an understanding of a system as complex as the respiratory system is difficult if not impossible via experimental methods alone. Computational models offer a complementary method to unravel the structure-function relationships occurring within a multiscale, multiphysics system such as this. Here we review the current

  18. Space radiation-associated lung injury in a murine model.

    PubMed

    Christofidou-Solomidou, Melpo; Pietrofesa, Ralph A; Arguiri, Evguenia; Schweitzer, Kelly S; Berdyshev, Evgeny V; McCarthy, Maureen; Corbitt, Astrid; Alwood, Joshua S; Yu, Yongjia; Globus, Ruth K; Solomides, Charalambos C; Ullrich, Robert L; Petrache, Irina

    2015-03-01

    Despite considerable progress in identifying health risks to crewmembers related to exposure to galactic/cosmic rays and solar particle events (SPE) during space travel, its long-term effects on the pulmonary system are unknown. We used a murine risk projection model to investigate the impact of exposure to space-relevant radiation (SR) on the lung. C3H mice were exposed to (137)Cs gamma rays, protons (acute, low-dose exposure mimicking the 1972 SPE), 600 MeV/u (56)Fe ions, or 350 MeV/u (28)Si ions at the NASA Space Radiation Laboratory at Brookhaven National Laboratory. Animals were irradiated at the age of 2.5 mo and evaluated 23.5 mo postirradiation, at 26 mo of age. Compared with age-matched nonirradiated mice, SR exposures led to significant air space enlargement and dose-dependent decreased systemic oxygenation levels. These were associated with late mild lung inflammation and prominent cellular injury, with significant oxidative stress and apoptosis (caspase-3 activation) in the lung parenchyma. SR, especially high-energy (56)Fe or (28)Si ions markedly decreased sphingosine-1-phosphate levels and Akt- and p38 MAPK phosphorylation, depleted anti-senescence sirtuin-1 and increased biochemical markers of autophagy. Exposure to SR caused dose-dependent, pronounced late lung pathological sequelae consistent with alveolar simplification and cellular signaling of increased injury and decreased repair. The associated systemic hypoxemia suggested that this previously uncharacterized space radiation-associated lung injury was functionally significant, indicating that further studies are needed to define the risk and to develop appropriate lung-protective countermeasures for manned deep space missions. PMID:25526737

  19. Space radiation-associated lung injury in a murine model

    PubMed Central

    Pietrofesa, Ralph A.; Arguiri, Evguenia; Schweitzer, Kelly S.; Berdyshev, Evgeny V.; McCarthy, Maureen; Corbitt, Astrid; Alwood, Joshua S.; Yu, Yongjia; Globus, Ruth K.; Solomides, Charalambos C.; Ullrich, Robert L.; Petrache, Irina

    2014-01-01

    Despite considerable progress in identifying health risks to crewmembers related to exposure to galactic/cosmic rays and solar particle events (SPE) during space travel, its long-term effects on the pulmonary system are unknown. We used a murine risk projection model to investigate the impact of exposure to space-relevant radiation (SR) on the lung. C3H mice were exposed to 137Cs gamma rays, protons (acute, low-dose exposure mimicking the 1972 SPE), 600 MeV/u 56Fe ions, or 350 MeV/u 28Si ions at the NASA Space Radiation Laboratory at Brookhaven National Laboratory. Animals were irradiated at the age of 2.5 mo and evaluated 23.5 mo postirradiation, at 26 mo of age. Compared with age-matched nonirradiated mice, SR exposures led to significant air space enlargement and dose-dependent decreased systemic oxygenation levels. These were associated with late mild lung inflammation and prominent cellular injury, with significant oxidative stress and apoptosis (caspase-3 activation) in the lung parenchyma. SR, especially high-energy 56Fe or 28Si ions markedly decreased sphingosine-1-phosphate levels and Akt- and p38 MAPK phosphorylation, depleted anti-senescence sirtuin-1 and increased biochemical markers of autophagy. Exposure to SR caused dose-dependent, pronounced late lung pathological sequelae consistent with alveolar simplification and cellular signaling of increased injury and decreased repair. The associated systemic hypoxemia suggested that this previously uncharacterized space radiation-associated lung injury was functionally significant, indicating that further studies are needed to define the risk and to develop appropriate lung-protective countermeasures for manned deep space missions. PMID:25526737

  20. Lung flooding enables efficient lung sonography and tumour imaging in human ex vivo and porcine in vivo lung cancer model

    PubMed Central

    2013-01-01

    Background Sonography has become the imaging technique of choice for guiding intraoperative interventions in abdominal surgery. Due to artefacts from residual air content, however, videothoracoscopic and open intraoperative ultrasound-guided thermoablation of lung malignancies are impossible. Lung flooding is a new method that allows complete ultrasound imaging of lungs and their tumours. Methods Fourteen resected tumourous human lung lobes were examined transpleurally with B-mode ultrasound before (in atelectasis) and after lung flooding with isotonic saline solution. In two swine, the left lung was filled with 15 ml/kg isotonic saline solution through the left side of a double-lumen tube. Lung tumours were simulated by transthoracic ultrasound-guided injection of 5 ml of purified bovine serum albumin in glutaraldehyde, centrally into the left lower lung lobe. The rate of tumour detection, the severity of disability caused by residual gas, and sonomorphology of the lungs and tumours were assessed. Results The ex vivo tumour detection rate was 100% in flooded human lung lobes and 43% (6/14) in atelectatic lungs. In all cases of atelectasis, sonographic tumour imaging was impaired by residual gas. Tumours and atelectatic tissue were isoechoic. In 28% of flooded lungs, a little residual gas was observed that did not impair sonographic tumour imaging. In contrast to tumours, flooded lung tissue was hyperechoic, homogeneous, and of fine-grained structure. Because of the bronchial wall three-laminar structure, sonographic differentiation of vessels and bronchi was possible. In all cases, malignant tumours in the flooded lung appeared well-demarcated from the lung parenchyma. Adenocarcinoma, squamous, and large cell carcinomas were hypoechoic. Bronchioloalveolar cell carcinoma was slightly hyperechoic. Transpleural sonography identifies endobronchial tumour growth and bronchial wall destruction. With transthoracic sonography, the flooded animal lung can be completely

  1. Organoids as a model system for studying human lung development and disease.

    PubMed

    Nadkarni, Rohan R; Abed, Soumeya; Draper, Jonathan S

    2016-05-01

    The lung is a complex organ comprising multiple cell types that perform a variety of vital processes, including immune defense and gas exchange. Diseases of the lung, such as chronic obstructive pulmonary disease, asthma and lung cancer, together represent one of the largest causes of patient suffering and mortality. Logistical barriers that hamper access to embryonic, normal adult or diseased lung tissue currently hinder the study of lung disease. In vitro lung modeling represents an attractive and accessible avenue for investigating lung development, function and disease pathology, but accurately modeling the lung in vitro requires a system that recapitulates the structural features of the native lung. Organoids are stem cell-derived three-dimensional structures that are supported by an extracellular matrix and contain multiple cell types whose spatial arrangement and interactions mimic those of the native organ. Recently, organoids representative of the respiratory system have been generated from adult lung stem cells and human pluripotent stem cells. Ongoing studies are showing that organoids may be used to model human lung development, and can serve as a platform for interrogating the function of lung-related genes and signalling pathways. In a therapeutic context, organoids may be used for modeling lung diseases, and as a platform for screening for drugs that alleviate respiratory disease. Here, we summarize the organoid-forming capacity of respiratory cells, current lung organoid technologies and their potential use in future therapeutic applications. PMID:26721435

  2. Morphological impact of zinc oxide particles on the antibacterial activity and human epithelia toxicity.

    PubMed

    Čepin, Marjeta; Hribar, Gorazd; Caserman, Simon; Orel, Zorica Crnjak

    2015-01-01

    ZnO nanoparticles are utilized in an ever growing number of products and can, therefore, be readily encountered in our everyday life. Human beings' outermost tissues consist of different epithelia and are, therefore, the most exposed to materials from the environment. In this paper, Caco-2 and Calu-3 cell lines were used, having been previously broadly applied for in vitro modelling of intestinal and respiratory epithelia, respectively. The toxicity of synthesized micro-, submicro- and nanoparticulate ZnO on these epithelia was measured and compared to the efficacy of the same ZnO particles as antibacterial agents. An approximately four-fold excess in antibacterial activity of ZnO nanoparticles over ZnO granulate was observed. The results of this paper reveal a sharp distinction between toxic nanoparticulate ZnO and safe ZnO particles of larger sizes in intestinal and airway in vitro epithelial models. In contrast, ZnO of larger particle sizes had only modestly lower antibacterial activity, which can be compensated for with higher dosing. These results show that nanoparticulate ZnO requires critical in vivo assessment before application. PMID:25953559

  3. Bayesian analysis of a disability model for lung cancer survival.

    PubMed

    Armero, C; Cabras, S; Castellanos, M E; Perra, S; Quirós, A; Oruezábal, M J; Sánchez-Rubio, J

    2016-02-01

    Bayesian reasoning, survival analysis and multi-state models are used to assess survival times for Stage IV non-small-cell lung cancer patients and the evolution of the disease over time. Bayesian estimation is done using minimum informative priors for the Weibull regression survival model, leading to an automatic inferential procedure. Markov chain Monte Carlo methods have been used for approximating posterior distributions and the Bayesian information criterion has been considered for covariate selection. In particular, the posterior distribution of the transition probabilities, resulting from the multi-state model, constitutes a very interesting tool which could be useful to help oncologists and patients make efficient and effective decisions. PMID:22767866

  4. The beetle amnion and serosa functionally interact as apposed epithelia

    PubMed Central

    Hilbrant, Maarten; Horn, Thorsten; Koelzer, Stefan; Panfilio, Kristen A

    2016-01-01

    Unlike passive rupture of the human chorioamnion at birth, the insect extraembryonic (EE) tissues – the amnion and serosa – actively rupture and withdraw in late embryogenesis. Withdrawal is essential for development and has been a morphogenetic puzzle. Here, we use new fluorescent transgenic lines in the beetle Tribolium castaneum to show that the EE tissues dynamically form a basal-basal epithelial bilayer, contradicting the previous hypothesis of EE intercalation. We find that the EE tissues repeatedly detach and reattach throughout development and have distinct roles. Quantitative live imaging analyses show that the amnion initiates EE rupture in a specialized anterior-ventral cap. RNAi phenotypes demonstrate that the serosa contracts autonomously. Thus, apposition in a bilayer enables the amnion as 'initiator' to coordinate with the serosa as 'driver' to achieve withdrawal. This EE strategy may reflect evolutionary changes within the holometabolous insects and serves as a model to study interactions between developing epithelia. DOI: http://dx.doi.org/10.7554/eLife.13834.001 PMID:26824390

  5. Identification of differentially expressed genes from multipotent epithelia at the onset of an asexual development

    PubMed Central

    Ricci, Lorenzo; Chaurasia, Ankita; Lapébie, Pascal; Dru, Philippe; Helm, Rebecca R.; Copley, Richard R.; Tiozzo, Stefano

    2016-01-01

    Organisms that have evolved alternative modes of reproduction, complementary to the sexual mode, are found across metazoans. The chordate Botryllus schlosseri is an emerging model for asexual development studies. Botryllus can rebuild its entire body from a portion of adult epithelia in a continuous and stereotyped process called blastogenesis. Anatomy and ontogenies of blastogenesis are well described, however molecular signatures triggering this developmental process are entirely unknown. We isolated tissues at the site of blastogenesis onset and from the same epithelia where this process is never triggered. We linearly amplified an ultra-low amount of mRNA (<10ng) and generated three transcriptome datasets. To provide a conservative landscape of transcripts differentially expressed between blastogenic vs. non-blastogenic epithelia we compared three different mapping and analysis strategies with a de novo assembled transcriptome and partially assembled genome as references, additionally a self-mapping strategy on the dataset. A subset of differentially expressed genes were analyzed and validated by in situ hybridization. The comparison of different analyses allowed us to isolate stringent sets of target genes, including transcripts with potential involvement in the onset of a non-embryonic developmental pathway. The results provide a good entry point to approach regenerative event in a basal chordate. PMID:27264734

  6. Identification of differentially expressed genes from multipotent epithelia at the onset of an asexual development.

    PubMed

    Ricci, Lorenzo; Chaurasia, Ankita; Lapébie, Pascal; Dru, Philippe; Helm, Rebecca R; Copley, Richard R; Tiozzo, Stefano

    2016-01-01

    Organisms that have evolved alternative modes of reproduction, complementary to the sexual mode, are found across metazoans. The chordate Botryllus schlosseri is an emerging model for asexual development studies. Botryllus can rebuild its entire body from a portion of adult epithelia in a continuous and stereotyped process called blastogenesis. Anatomy and ontogenies of blastogenesis are well described, however molecular signatures triggering this developmental process are entirely unknown. We isolated tissues at the site of blastogenesis onset and from the same epithelia where this process is never triggered. We linearly amplified an ultra-low amount of mRNA (<10ng) and generated three transcriptome datasets. To provide a conservative landscape of transcripts differentially expressed between blastogenic vs. non-blastogenic epithelia we compared three different mapping and analysis strategies with a de novo assembled transcriptome and partially assembled genome as references, additionally a self-mapping strategy on the dataset. A subset of differentially expressed genes were analyzed and validated by in situ hybridization. The comparison of different analyses allowed us to isolate stringent sets of target genes, including transcripts with potential involvement in the onset of a non-embryonic developmental pathway. The results provide a good entry point to approach regenerative event in a basal chordate. PMID:27264734

  7. Basolateral localization of fiber receptors limits adenovirus infection from the apical surface of airway epithelia.

    PubMed

    Walters, R W; Grunst, T; Bergelson, J M; Finberg, R W; Welsh, M J; Zabner, J

    1999-04-01

    Recent identification of two receptors for the adenovirus fiber protein, coxsackie B and adenovirus type 2 and 5 receptor (CAR), and the major histocompatibility complex (MHC) Class I alpha-2 domain allows the molecular basis of adenoviral infection to be investigated. Earlier work has shown that human airway epithelia are resistant to infection by adenovirus. Therefore, we examined the expression and localization of CAR and MHC Class I in an in vitro model of well differentiated, ciliated human airway epithelia. We found that airway epithelia express CAR and MHC Class I. However, neither receptor was present in the apical membrane; instead, both were polarized to the basolateral membrane. These findings explain the relative resistance to adenovirus infection from the apical surface. In contrast, when the virus was applied to the basolateral surface, gene transfer was much more efficient because of an interaction of adenovirus fiber with its receptors. In addition, when the integrity of the tight junctions was transiently disrupted, apically applied adenovirus gained access to the basolateral surface and enhanced gene transfer. These data suggest that the receptors required for efficient infection are not available on the apical surface, and interventions that allow access to the basolateral space where fiber receptors are located increase gene transfer efficiency. PMID:10187807

  8. Precancerous esophageal epithelia are associated with significantly increased scattering coefficients

    PubMed Central

    Su, Jing-Wei; Lin, Yang-Hsien; Chiang, Chun-Ping; Lee, Jang-Ming; Hsieh, Chao-Mao; Hsieh, Min-Shu; Yang, Pei-Wen; Wang, Chen-Ping; Tseng, Ping-Huei; Lee, Yi-Chia; Sung, Kung-Bin

    2015-01-01

    The progression of epithelial precancers into cancer is accompanied by changes of tissue and cellular structures in the epithelium. Correlations between the structural changes and scattering coefficients of esophageal epithelia were investigated using quantitative phase images and the scattering-phase theorem. An ex vivo study of 14 patients demonstrated that the average scattering coefficient of precancerous epithelia was 37.8% higher than that of normal epithelia from the same patient. The scattering coefficients were highly correlated with morphological features including the cell density and the nuclear-to-cytoplasmic ratio. A high interpatient variability in scattering coefficients was observed and suggests identifying precancerous lesions based on the relative change in scattering coefficients. PMID:26504630

  9. Precancerous esophageal epithelia are associated with significantly increased scattering coefficients.

    PubMed

    Su, Jing-Wei; Lin, Yang-Hsien; Chiang, Chun-Ping; Lee, Jang-Ming; Hsieh, Chao-Mao; Hsieh, Min-Shu; Yang, Pei-Wen; Wang, Chen-Ping; Tseng, Ping-Huei; Lee, Yi-Chia; Sung, Kung-Bin

    2015-10-01

    The progression of epithelial precancers into cancer is accompanied by changes of tissue and cellular structures in the epithelium. Correlations between the structural changes and scattering coefficients of esophageal epithelia were investigated using quantitative phase images and the scattering-phase theorem. An ex vivo study of 14 patients demonstrated that the average scattering coefficient of precancerous epithelia was 37.8% higher than that of normal epithelia from the same patient. The scattering coefficients were highly correlated with morphological features including the cell density and the nuclear-to-cytoplasmic ratio. A high interpatient variability in scattering coefficients was observed and suggests identifying precancerous lesions based on the relative change in scattering coefficients. PMID:26504630

  10. Glucose transport by epithelia prepared from harvested enterocytes.

    PubMed

    Kimura, Yasuhiro; van der Merwe, Marie; Bering, Stine B; Penmatsa, Himabindu; Conoley, Veronica G; Sangild, Per T; Naren, Anjaparavanda P; Buddington, Randal K

    2015-01-01

    Transformed and cultured cell lines have significant shortcomings for investigating the characteristics and responses of native villus enterocytes in situ. Interpretations of results from intact tissues are complicated by the presence of underlying tissues and the crypt compartment. We describe a simple, novel, and reproducible method for preparing functional epithelia using differentiated enterocytes harvested from the small intestine upper villus of adult mice and preterm pigs with and without necrotizing enterocolitis. Concentrative, rheogenic glucose uptake was used as an indicator of epithelial function and was demonstrated by cellular accumulation of tracer (14)C D-glucose and Ussing chamber based short-circuit currents. Assessment of the epithelia by light and immunofluorescent microscopy revealed the harvested enterocytes remain differentiated and establish cell-cell connections to form polarized epithelia with distinct apical and basolateral domains. As with intact tissues, the epithelia exhibit glucose induced short-circuit currents that are increased by exposure to adenosine and adenosine 5'-monophosphate (AMP) and decreased by phloridzin to inhibit the apical glucose transporter SGLT-1. Similarly, accumulation of (14)C D-glucose by the epithelia was inhibited by phloridzin, but not phloretin, and was stimulated by pre-exposure to AMP and adenosine, apparently by a microtubule-based mechanism that is disrupted by nocodazole, with the magnitudes of responses to adenosine, forskolin, and health status exceeding those we have measured using intact tissues. Our findings indicate that epithelia prepared from harvested enterocytes provide an alternative approach for comparative studies of the characteristics of nutrient transport by the upper villus epithelium and the responses to different conditions and stimuli. PMID:24166597

  11. Description of MISCAN-Lung, the Erasmus MC Lung Cancer Micro-Simulation Model for Evaluating Cancer Control Interventions

    PubMed Central

    Schultz, F.W.; Boer, R.; de Koning, H.J.

    2012-01-01

    The MISCAN-lung model was designed to simulate population trends in lung cancer (LC) for comprehensive surveillance of the disease, to relate past exposure to risk factors to (observed) LC incidence and mortality, and to estimate the impact of cancer-control interventions. MISCAN-lung employs the technique of stochastic micro-simulation of life histories affected by risk factors. It includes the two-stage clonal expansion model for carcinogenesis and a detailed LC progression model; the latter is specifically intended for the evaluation of screenings. This paper elucidates further the principles of MISCAN-lung and describes its application to a comparative study within the CISNET Lung Working Group on the impact of tobacco control on U.S. LC mortality. MISCAN-lung yields an estimate of the number of LC deaths avoided during 1975–2000. The potential number of avoidable LC deaths, had everybody quit smoking in 1965, is 2.2 million. 750,000 deaths (30%) were avoided in the U.S. due to actual tobacco control interventions. The model fits in the actual tobacco-control scenario, providing credibility to the estimates of other scenarios, although considering survey-reported smoking trends alone has limitations. PMID:22882895

  12. A canine model of beryllium-induced granulomatous lung disease

    SciTech Connect

    Haley, P.J.; Finch, G.L.; Mewhinney, J.A.; Harmsen, A.G.; Hahn, F.F.; Hoover, M.D.; Muggenburg, B.A.; Bice, D.E. )

    1989-08-01

    Groups of beagle dogs were exposed by inhalation to attain either low or high initial lung burdens (ILB) of BeO calcined at 500 degrees or 1000 degrees C. Dogs were killed at 8, 32, 64, 180, and 365 days after exposure for evaluation of beryllium tissue burdens and histopathologic examination. Histologic lesions were characterized by perivascular and peribronchiolar infiltrates of lymphocytes and macrophages 8 days after exposure. These lesions progressed to distinct microgranulomas accompanied by patchy granulomatous pneumonia. Lesions were more severe in dogs exposed to 500 degrees C BeO. Additional dogs were sampled by bronchoalveolar lavage at 3, 6, 7, 11, 15, 18, and 22 months after exposure for characterization of lung cytology and lung immune responses. Lymphocyte percentages and numbers were increased in lavage samples 3 months after exposure in dogs with both the high and low ILB of 500 degrees C. Values for both parameters decreased rapidly thereafter. Dogs with either low or high ILB of 1000 degrees C-treated BeO displayed negligible to low and variable changes in both lymphocyte percentages and numbers. In vitro lymphocyte stimulation by beryllium was increased 180 and 210 days after exposure in dogs with the high ILB 500 degrees C BeO only. A marked degree of individual variation in both histologic lesions and lymphocyte responses among dogs was noted. Less soluble 1000 degrees C-treated BeO was retained in the lung longer than the more soluble 500 degrees C-treated material that was cleared almost entirely by 1 year after exposure. Because these changes are similar to those reported in humans with chronic beryllium disease, these data suggest that the beagle represents a good model to study histologic and immunologic aspects of this disease syndrome.

  13. Image-based modeling of lung structure and function

    PubMed Central

    Tawhai, Merryn H.; Lin, Ching-Long

    2010-01-01

    Current state-of-the-art in image-based modeling allows derivation of patient-specific models of the lung, lobes, airways, and pulmonary vascular trees. The application of traditional engineering analyses of fluid and structural mechanics to image-based subject-specific models has the potential to provide new insight into structure-function relationships in the individual via functional interpretation that complements imaging and experimental studies. Three major issues that are encountered in studies of air flow through the bronchial airways are the representation of airway geometry, the imposition of physiological boundary conditions, and the treatment of turbulence. Here we review some efforts to resolve each of these issues, with particular focus on image-based models that have been developed to simulate air flow from the mouth to the terminal bronchiole, and subjected to physiologically meaningful boundary conditions via image registration and soft tissue mechanics models. PMID:21105146

  14. Lung Cancer Signatures in Plasma Based on Proteome Profiling of Mouse Tumor Models

    PubMed Central

    Taguchi, Ayumu; Politi, Katerina; Pitteri, Sharon J.; Lockwood, William W.; Faça, Vitor M.; Kelly-Spratt, Karen; Wong, Chee-Hong; Zhang, Qing; Chin, Alice; Park, Kwon-Sik; Goodman, Gary; Gazdar, Adi F.; Sage, Julien; Dinulescu, Daniela M.; Kucherlapati, Raju; DePinho, Ronald A.; Kemp, Christopher J.; Varmus, Harold E.; Hanash, Samir M.

    2012-01-01

    SUMMARY We investigated the potential of in-depth quantitative proteomics to reveal plasma protein signatures that reflect lung tumor biology. We compared plasma protein profiles of four mouse models of lung cancer with profiles of models of pancreatic, ovarian, colon, prostate, and breast cancer and two models of inflammation. A protein signature for Titf1/Nkx2-1, a known lineage-survival oncogene in lung cancer, was found in plasmas of mouse models of lung adenocarcinoma. An EGFR signature was found in plasma of an EGFR mutant model, and a distinct plasma signature related to neuroendocrine development was uncovered in the small-cell lung cancer model. We demonstrate relevance to human lung cancer of the protein signatures identified on the basis of mouse models. PMID:21907921

  15. Lung cancer signatures in plasma based on proteome profiling of mouse tumor models.

    PubMed

    Taguchi, Ayumu; Politi, Katerina; Pitteri, Sharon J; Lockwood, William W; Faça, Vitor M; Kelly-Spratt, Karen; Wong, Chee-Hong; Zhang, Qing; Chin, Alice; Park, Kwon-Sik; Goodman, Gary; Gazdar, Adi F; Sage, Julien; Dinulescu, Daniela M; Kucherlapati, Raju; Depinho, Ronald A; Kemp, Christopher J; Varmus, Harold E; Hanash, Samir M

    2011-09-13

    We investigated the potential of in-depth quantitative proteomics to reveal plasma protein signatures that reflect lung tumor biology. We compared plasma protein profiles of four mouse models of lung cancer with profiles of models of pancreatic, ovarian, colon, prostate, and breast cancer and two models of inflammation. A protein signature for Titf1/Nkx2-1, a known lineage-survival oncogene in lung cancer, was found in plasmas of mouse models of lung adenocarcinoma. An EGFR signature was found in plasma of an EGFR mutant model, and a distinct plasma signature related to neuroendocrine development was uncovered in the small-cell lung cancer model. We demonstrate relevance to human lung cancer of the protein signatures identified on the basis of mouse models. PMID:21907921

  16. Mechanisms of Regulating Cell Topology in Proliferating Epithelia: Impact of Division Plane, Mechanical Forces, and Cell Memory

    PubMed Central

    Li, Yingzi; Naveed, Hammad; Kachalo, Sema; Xu, Lisa X.; Liang, Jie

    2012-01-01

    Regulation of cell growth and cell division has a fundamental role in tissue formation, organ development, and cancer progression. Remarkable similarities in the topological distributions were found in a variety of proliferating epithelia in both animals and plants. At the same time, there are species with significantly varied frequency of hexagonal cells. Moreover, local topology has been shown to be disturbed on the boundary between proliferating and quiescent cells, where cells have fewer sides than natural proliferating epithelia. The mechanisms of regulating these topological changes remain poorly understood. In this study, we use a mechanical model to examine the effects of orientation of division plane, differential proliferation, and mechanical forces on animal epithelial cells. We find that regardless of orientation of division plane, our model can reproduce the commonly observed topological distributions of cells in natural proliferating animal epithelia with the consideration of cell rearrangements. In addition, with different schemes of division plane, we are able to generate different frequency of hexagonal cells, which is consistent with experimental observations. In proliferating cells interfacing quiescent cells, our results show that differential proliferation alone is insufficient to reproduce the local changes in cell topology. Rather, increased tension on the boundary, in conjunction with differential proliferation, can reproduce the observed topological changes. We conclude that both division plane orientation and mechanical forces play important roles in cell topology in animal proliferating epithelia. Moreover, cell memory is also essential for generating specific topological distributions. PMID:22912800

  17. Comparison of DNA-lipid complexes and DNA alone for gene transfer to cystic fibrosis airway epithelia in vivo.

    PubMed Central

    Zabner, J; Cheng, S H; Meeker, D; Launspach, J; Balfour, R; Perricone, M A; Morris, J E; Marshall, J; Fasbender, A; Smith, A E; Welsh, M J

    1997-01-01

    Cationic lipids show promise as vectors for transfer of CFTR cDNA to airway epithelia of patients with cystic fibrosis (CF). However, previous studies have not compared the effect of DNA-lipid to DNA alone. Recently, we developed a formulation of plasmid encoding CFTR (pCF1-CFTR) and cationic lipid (GL-67:DOPE) that generated greater gene transfer in mouse lung than previously described DNA-lipid vectors. Therefore, we tested the hypothesis that DNA-lipid complexes were more effective than DNA alone at transferring CFTR cDNA to airway epithelia in vivo. We administered complexes of DNA-lipid to one nostril and DNA alone to the other nostril in a randomized, double-blind study. Electrophysiologic measurements showed that DNA-lipid complexes partially corrected the Cl- transport defect. Importantly, the pCF1-CFTR plasmid alone was at least as effective as complexes of DNA with lipid. Measurements of vector-specific CFTR transcripts also showed gene transfer with both DNA-lipid and DNA alone. These results indicate that nonviral vectors can transfer CFTR cDNA to airway epithelia and at least partially restore the Cl- transport defect characteristic of CF. However, improvements in the overall efficacy of gene transfer are required to develop a treatment for CF. PMID:9294121

  18. A biomathematical model of particle clearance and retention in the lungs of coal miners.

    PubMed

    Kuempel, E D; O'Flaherty, E J; Stayner, L T; Smith, R J; Green, F H; Vallyathan, V

    2001-08-01

    To understand better the factors influencing the relationships among airborne particle exposure, lung burden, and fibrotic lung disease, we developed a biologically based kinetic model to predict the long-term retention of particles in the lungs of coal miners. This model includes alveolar, interstitial, and hilar lymph node compartments. The 131 miners in this study had worked in the Beckley, West Virginia, area and died during the 1960s. The data used to develop this model include exposure to respirable coal mine dust by intensity and duration within each job, lung and lymph node dust burdens at autopsy, pathological classification of fibrotic lung disease, and smoking history. Initial parameter estimates for this model were based on both human and animal data of particle deposition and clearance and on the biological and physical factors influencing these processes. Parameter estimation and model fit to the data were determined using least squares. Results show that the end-of-life lung dust burdens in these coal miners were substantially higher than expected from first-order clearance kinetics, yet lower than expected from the overloading of alveolar clearance predicted from rodent studies. The best-fitting and most parsimonious model includes processes for first-order alveolar-macrophage-mediated clearance and transfer of particles to the lung interstitium. These results are consistent with the particle retention patterns observed previously in the lungs of primates. The findings indicate that rodent models extrapolated to humans, without adjustment for the kinetic differences in particle clearance and retention, would be inadequate for predicting lung dust burdens in humans. Also, this human lung kinetic model predicts greater retained lung dust burdens from occupational exposure than predicted from current human models based on lower exposure data. This model is useful for risk assessment of particle-induced lung diseases, by estimating equivalent internal

  19. Emergence and Dynamics of Polar Order in Developing Epithelia

    NASA Astrophysics Data System (ADS)

    Farhadifar, Reza

    2011-03-01

    Planar Cell Polarity (PCP) is a conserved process in many vertebrate and invertebrate tissues, and is fundamental for the coordination of cell behavior and patterning. A well-studied example is the orientational pattern of hairs in the wing of the adult fruit fly Drosophila, which is an important model organism in biology. The Drosophila wing is an epithelium, i.e., a two-dimensional sheet of cells, which grows from a few cells to thousands of cells during the course of development. In the wing epithelium, planar polarity is established by an anisotropic distribution of PCP proteins within cells. The distribution of these proteins in a given cell affects the polarity of neighboring cells, such that at the end of wing development a large-scale PCP orientational order emerges. Here we present a theoretical study of planar polarity in developing epithelia based on a vertex model, which takes into account cell mechanics, cell adhesion, and cell division, combined with experimental results obtained from time-lapse imaging of the wing development. We show that in experiment, polarity order does not develop de novo at the end of wing development, but rather cells are initially polarized at an angle with respect to their final polarity axis. During wing development, the polarity axes of cells reorient towards their final direction. We identify a basic mechanism to generate such a large-scale initial polarization, based on the growth of a small number of cells with an initially random PCP distribution. Finally, we study the effect of shear and oriented cell division on dynamics of PCP order, showing that these two processes can robustly reorient the polarity axes of cells.

  20. Evidence of inherent spontaneous polarization in the metazoan integument epithelia.

    PubMed Central

    Athenstaedt, H; Claussen, H

    1983-01-01

    The live integument epithelia of the metazoa have an inherent spontaneous polarization (an inherent permanent electric dipole moment) of corresponding direction perpendicular to the integument surface. The existence of the inherent polarization was proved by their temperature dependence, i.e., by the pyroelectric (PE) effect. Quantitative PE measurements were carried out on a number of integument epithelia of vertebrates (a) in vivo, (b) on fresh epidermis preparations, and (c) on dead, air-dried epidermis specimens of the same species. The demonstrated spontaneous polarization is not dependent on the living state and not caused by a potential difference between the outer and inner integument surface. Dead, dry epidermis samples (potential difference less than 0.01 mV) as well as dead, dry integument appendages (bristles, hairs), and dead cuticles (of arthropoda, annelida, nematoda) showed an inherent dipole moment of the same orientation as the live epidermis. The findings reveal a relationship between the direction (vector) of inherent spontaneous polarization and that of growth (morphogenesis) in the animal epidermis, their appendages, and cuticles. We conclude (a) that the inherent spontaneous polarization is present in live individual epithelial cells of the metazoan integument, and (b) that this physical property is related to the structural and functional cell polarity of integument epithelia and possibly of other epithelia. Images FIGURE 10 PMID:6838974

  1. Modeling Granulomas in Response to Infection in the Lung.

    PubMed

    Hao, Wenrui; Schlesinger, Larry S; Friedman, Avner

    2016-01-01

    Alveolar macrophages play a large role in the innate immune response of the lung. However, when these highly immune-regulatory cells are unable to eradicate pathogens, the adaptive immune system, which includes activated macrophages and lymphocytes, particularly T cells, is called upon to control the pathogens. This collection of immune cells surrounds, isolates and quarantines the pathogen, forming a small tissue structure called a granuloma for intracellular pathogens like Mycobacterium tuberculosis (Mtb). In the present work we develop a mathematical model of the dynamics of a granuloma by a system of partial differential equations. The 'strength' of the adaptive immune response to infection in the lung is represented by a parameter α, the flux rate by which T cells and M1 macrophages that immigrated from the lymph nodes enter into the granuloma through its boundary. The parameter α is negatively correlated with the 'switching time', namely, the time it takes for the number of M1 type macrophages to surpass the number of infected, M2 type alveolar macrophages. Simulations of the model show that as α increases the radius of the granuloma and bacterial load in the granuloma both decrease. The model is used to determine the efficacy of potential host-directed therapies in terms of the parameter α, suggesting that, with fixed dosing level, an infected individual with a stronger immune response will receive greater benefits in terms of reducing the bacterial load. PMID:26986986

  2. Modeling Granulomas in Response to Infection in the Lung

    PubMed Central

    Hao, Wenrui; Schlesinger, Larry S.; Friedman, Avner

    2016-01-01

    Alveolar macrophages play a large role in the innate immune response of the lung. However, when these highly immune-regulatory cells are unable to eradicate pathogens, the adaptive immune system, which includes activated macrophages and lymphocytes, particularly T cells, is called upon to control the pathogens. This collection of immune cells surrounds, isolates and quarantines the pathogen, forming a small tissue structure called a granuloma for intracellular pathogens like Mycobacterium tuberculosis (Mtb). In the present work we develop a mathematical model of the dynamics of a granuloma by a system of partial differential equations. The ‘strength’ of the adaptive immune response to infection in the lung is represented by a parameter α, the flux rate by which T cells and M1 macrophages that immigrated from the lymph nodes enter into the granuloma through its boundary. The parameter α is negatively correlated with the ‘switching time’, namely, the time it takes for the number of M1 type macrophages to surpass the number of infected, M2 type alveolar macrophages. Simulations of the model show that as α increases the radius of the granuloma and bacterial load in the granuloma both decrease. The model is used to determine the efficacy of potential host-directed therapies in terms of the parameter α, suggesting that, with fixed dosing level, an infected individual with a stronger immune response will receive greater benefits in terms of reducing the bacterial load. PMID:26986986

  3. Mighty mouse breakthroughs: a Sox2-driven model for squamous cell lung cancer

    PubMed Central

    Mukhopadhyay, Anandaroop; Oliver, Trudy G

    2015-01-01

    Squamous lung cancer is a subtype of non-small cell lung cancer with a poor overall prognosis. We have recently generated a mouse model of squamous lung carcinoma by overexpressing Sex-determining region Y-box 2 (Sox2) and deleting liver kinase B1 (Lkb1) using a lentiviral approach. This model recapitulates the human disease in terms of histopathology, biomarker expression, and signaling pathway activation, making it an excellent model for preclinical studies. PMID:27308419

  4. Experimental evolution of sprays in a lung model

    NASA Astrophysics Data System (ADS)

    Burguete, Javier; Aliseda, Alberto

    2015-11-01

    We present the first results of an experiment conceived to observe the evolution of sprays inside the lungs. We have built a model that covers the first 6 generations (from the trachea to segmental bronchi of 5th generation). This setup is placed on a wind tunnel, and the flow inside the model is induced by a vacuum pump that emulates the breathing process using a valve. We inject a previously determined distribution of particles (water droplets), whose average diameter can be modified. Then, we measure the droplet distribution in different branches and compare how the droplet distribution is modified at each generation. The parameters that control the behavior are the average diameter of the original distribution, the airflow rate inside the model and the frequency of the breathing cycle.

  5. A Model of Anterograde Oxygenated Lung Blood Flow in Acardia.

    PubMed

    Marinakis, Sotirios; Burki, Marco; Abdel-Sayed, Saad; von Segesser, Ludwig Karl

    2016-01-01

    In extreme situations such as hyperacute rejection of heart transplant or major heart trauma, heart explantation and extracorporeal membrane oxygenation (ECMO) hemodynamic support might be the only means for survival. In our previous model of acardia, pulmonary artery (PA) was clamped and did not receive any anterograde blood flow. A model of anterograde PA perfusion might be necessary to avoid ischemic pulmonary damage in prolonged ECMO in acardia. The aim of this study was to describe the surgical technique and to determine the feasibility of an anterograde lung perfusion in acardia through the anastomosis of the right internal mammary artery (RIMA) to the PA. A venoarterial cardiopulmonary bypass was established in three pigs (72 ± 2.6 kg) by the transjugular insertion to the caval axis of a double-staged cannula with carotid artery return. Heart was excised and ECMO was established as previously reported. Right internal mammary artery was harvested and after measurement of its output (93.3 ± 5.8 ml/min, representing 2.17% ± 0.15% of total pump flow), it was anastomosed to PA. Right internal mammary artery anastomosis to PA is a feasible, safe, and easy to perform maneuver assuring an anterograde lung perfusion in acardia. PMID:27442854

  6. Multiresolution active contour model applied on lung and colon images

    NASA Astrophysics Data System (ADS)

    Dehmeshki, Jamshid; Siddique, Musib; Wong, Wing; Chis Ster, Irina

    2004-05-01

    This paper deploys a wavelet based scale-space approach to extract the boundary of the object of interest in medical CT images. The classical approach of the active contour models consists of starting with an initial contour, to deform it under the action of some forces attracting the contour towards the edges by means of a set of forces. The mathematical model involves in the minimisation of an objective function called energy functional, which depends on the geometry of the contour as well as of the image characteristics. Various strategies could be used for the formulation of the energy functional and its optimisation. In this study, a wavelet based scale-space approach has been adopted. The coarsest scale is able to enlarge the capture region surrounding an object and avoids the trapping of contour into weak edges. The finer scales are used to refine the contour as close as possible to the boundary of the object. An adaptive scale coefficient for the balloon energy has been introduced. Four levels of resolution have been applied in order to get reproducibility of the contour despite poor different initialisations. The scheme has been applied to segment the regions of interest in CT lung and colon images. The result has been shown to be accurate and reproducible for the cases containing fat, holes and other small high intensity objects inside lung nodules as well as colon polyps.

  7. Improving the channeler ant model for lung CT analysis

    NASA Astrophysics Data System (ADS)

    Cerello, Piergiorgio; Lopez Torres, Ernesto; Fiorina, Elisa; Oppedisano, Chiara; Peroni, Cristiana; Arteche Diaz, Raul; Bellotti, Roberto; Bosco, Paolo; Camarlinghi, Niccolo; Massafra, Andrea

    2011-03-01

    The Channeler Ant Model (CAM) is an algorithm based on virtual ant colonies, conceived for the segmentation of complex structures with different shapes and intensity in a 3D environment. It exploits the natural capabilities of virtual ant colonies to modify the environment and communicate with each other by pheromone deposition. When applied to lung CTs, the CAM can be turned into a Computer Aided Detection (CAD) method for the identification of pulmonary nodules and the support to radiologists in the identification of early-stage pathological objects. The CAM has been validated with the segmentation of 3D artificial objects and it has already been successfully applied to the lung nodules detection in Computed Tomography images within the ANODE09 challenge. The model improvements for the segmentation of nodules attached to the pleura and to the vessel tree are discussed, as well as a method to enhance the detection of low-intensity nodules. The results on five datasets annotated with different criteria show that the analytical modules (i.e. up to the filtering stage) provide a sensitivity in the 80 - 90% range with a number of FP/scan of the order of 20. The classification module, although not yet optimised, keeps the sensitivity in the 70 - 85% range at about 10 FP/scan, in spite of the fact that the annotation criteria for the training and the validation samples are different.

  8. Electroporation-mediated Delivery of Genes in Rodent Models of Lung Contusion

    PubMed Central

    Machado-Aranda, David; Raghavendran, Krishnan

    2015-01-01

    Several of the biological processes involved in the pathogenesis of acute lung injury and acute respiratory distress syndrome after lung contusion are regulated at a genetic and epigenetic level. Thus, strategies to manipulate gene expression in this context are highly desirable not only to elucidate the mechanisms involved but also to look for potential therapies. In the present chapter, we describe mouse and rat models of inducing blunt thoracic injury followed by electroporation-mediated gene delivery to the lung. Electroporation is a highly efficient and easily reproducible technique that allows circumvention of several of lung gene delivery challenges and safety issues present with other forms of lung gene therapy. PMID:24510825

  9. Hypervolemia induces and potentiates lung damage after recruitment maneuver in a model of sepsis-induced acute lung injury

    PubMed Central

    2010-01-01

    Introduction Recruitment maneuvers (RMs) seem to be more effective in extrapulmonary acute lung injury (ALI), caused mainly by sepsis, than in pulmonary ALI. Nevertheless, the maintenance of adequate volemic status is particularly challenging in sepsis. Since the interaction between volemic status and RMs is not well established, we investigated the effects of RMs on lung and distal organs in the presence of hypovolemia, normovolemia, and hypervolemia in a model of extrapulmonary lung injury induced by sepsis. Methods ALI was induced by cecal ligation and puncture surgery in 66 Wistar rats. After 48 h, animals were anesthetized, mechanically ventilated and randomly assigned to 3 volemic status (n = 22/group): 1) hypovolemia induced by blood drainage at mean arterial pressure (MAP)≈70 mmHg; 2) normovolemia (MAP≈100 mmHg), and 3) hypervolemia with colloid administration to achieve a MAP≈130 mmHg. In each group, animals were further randomized to be recruited (CPAP = 40 cm H2O for 40 s) or not (NR) (n = 11/group), followed by 1 h of protective mechanical ventilation. Echocardiography, arterial blood gases, static lung elastance (Est,L), histology (light and electron microscopy), lung wet-to-dry (W/D) ratio, interleukin (IL)-6, IL-1β, caspase-3, type III procollagen (PCIII), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) mRNA expressions in lung tissue, as well as lung and distal organ epithelial cell apoptosis were analyzed. Results We observed that: 1) hypervolemia increased lung W/D ratio with impairment of oxygenation and Est,L, and was associated with alveolar and endothelial cell damage and increased IL-6, VCAM-1, and ICAM-1 mRNA expressions; and 2) RM reduced alveolar collapse independent of volemic status. In hypervolemic animals, RM improved oxygenation above the levels observed with the use of positive-end expiratory pressure (PEEP), but increased lung injury and led to higher inflammatory and fibrogenetic

  10. CRM1-dependent p53 nuclear accumulation in lung lesions of a bitransgenic mouse lung tumor model.

    PubMed

    Chen, Lixia; Moore, Joseph E; Samathanam, Christina; Shao, Changxia; Cobos, Everardo; Miller, Mark Steven; Gao, Weimin

    2011-07-01

    The p53 tumor suppressor gene plays an essential role in tumorigenesis, and the chromosomal region maintenance 1 (CRM1) has been suggested to export p53 protein from the nucleus to the cytoplasm. The objectives of the present study were to evaluate p53 expression and subcellular localization as well as CRM1 expression using immunohistochemistry in our established bitransgenic mouse lung tumor model. In this model, expression of the mutant human Ki-rasG12C allele was regulated in a doxycycline (DOX)-inducible, lung-specific manner. Following treatment with curcumin, we found that although overall p53 expression levels were not significantly changed among the three groups, lung lesions in mice treated with DOX alone had the highest proportion of N>C (nucleus predominant) p53 staining (46±7%), followed by lung lesions in mice co-treated with DOX and curcumin (31±12%) and controls (17±4%). CRM1 expression was dramatically inhibited in lung lesions in mice treated with DOX (0±0) as compared to controls (90±17, P=0.001), and could be partially reversed after curcumin treatment (47±21, P=0.028, DOX vs. DOX+curcumin). Collectively, the results from this study demonstrated that p53 accumulated in the nucleus in lung lesions in mice expressing the mutant Ki-rasG12C transgene as a result of down-regulation of CRM1. Furthermore, these alterations could be partially reversed by curcumin treatment. p53 subcellular localization resulting from CRM1 alterations may play an important role in lung tumorigenesis. PMID:21519798

  11. Loss of Inositol 1,4,5-Trisphosphate Receptors From Bile Duct Epithelia Is a Common Event in Cholestasis

    PubMed Central

    SHIBAO, KAZUNORI; HIRATA, KEIJI; ROBERT, MARIE E.; NATHANSON, MICHAEL H.

    2010-01-01

    Background & Aims: Cholestasis is one of the principal manifestations of liver disease and often results from disorders involving bile duct epithelia rather than hepatocytes. A range of disorders affects biliary epithelia, and no unifying pathophysiologic event in these cells has been identified as the cause of cholestasis. Here we examined the role of the inositol 1,4,5-trisphosphate receptor (InsP3R)/Ca2+ release channel in Ca2+ signaling and ductular secretion in animal models of cholestasis and in patients with cholestatic disorders. Methods: The expression and distribution of the InsP3R and related proteins were examined in rat cholangiocytes before and after bile duct ligation or treatment with endotoxin. Ca2+ signaling was examined in isolated bile ducts from these animals, whereas ductular bicarbonate secretion was examined in isolated perfused livers. Confocal immunofluorescence was used to examine cholangiocyte InsP3R expression in human liver biopsy specimens. Results: Expression of the InsP3R was selectively lost from biliary epithelia after bile duct ligation or endotoxin treatment. As a result, Ca2+ signaling and Ca2+-mediated bicarbonate secretion were lost as well, although other components of the Ca2+ signaling pathway and adenosine 3′,5′-cyclic monophosphate (cAMP)-mediated bicarbonate secretion both were preserved. Examination of human liver biopsy specimens showed that InsP3Rs also were lost from bile duct epithelia in a range of human cholestatic disorders, although InsP3R expression was intact in noncholestatic liver disease. Conclusions: InsP3-mediated Ca2+ signaling in bile duct epithelia appears to be important for normal bile secretion in the liver, and loss of InsP3Rs may be a final common pathway for cholestasis. PMID:14517800

  12. Mean lung pressure during adult high-frequency oscillatory ventilation: an experimental study using a lung model.

    PubMed

    Hirayama, Takahiro; Nagano, Osamu; Shiba, Naoki; Yumoto, Tetsuya; Sato, Keiji; Terado, Michihisa; Ugawa, Toyomu; Ichiba, Shingo; Ujike, Yoshihito

    2014-12-01

    In adult high-frequency oscillatory ventilation (HFOV), stroke volume (SV) and mean lung pressure (PLung) are important for lung protection. We measured the airway pressure at the Y-piece and the lung pressure during HFOV using a lung model and HFOV ventilators for adults (R100 and 3100B). The lung model was made of a 20-liter, airtight rigid plastic container (adiabatic compliance: 19.3 ml/cmH2O) with or without a resistor (20 cmH2O/l/sec). The ventilator settings were as follows: mean airway pressure (MAP), 30 cmH2O; frequency, 5-15 Hz (every 1 Hz); airway pressure amplitude (AMP), maximum;and % of inspiratory time (IT), 50% for R100, 33% or 50% for 3100B. The measurements were also performed with an AMP of 2/3 or 1/3 maximum at 5, 10 and 15 Hz. The PLung and the measured MAP were not consistently identical to the setting MAP in either ventilator, and decreasing IT decreased the PLung in 3100B. In conclusion, we must pay attention to the possible discrepancy between the PLung and the setting MAP during adult HFOV. PMID:25519026

  13. A comprehensive computational model of sound transmission through the porcine lung

    PubMed Central

    Dai, Zoujun; Peng, Ying; Henry, Brian M.; Mansy, Hansen A.; Sandler, Richard H.; Royston, Thomas J.

    2014-01-01

    A comprehensive computational simulation model of sound transmission through the porcine lung is introduced and experimentally evaluated. This “subject-specific” model utilizes parenchymal and major airway geometry derived from x-ray CT images. The lung parenchyma is modeled as a poroviscoelastic material using Biot theory. A finite element (FE) mesh of the lung that includes airway detail is created and used in comsol FE software to simulate the vibroacoustic response of the lung to sound input at the trachea. The FE simulation model is validated by comparing simulation results to experimental measurements using scanning laser Doppler vibrometry on the surface of an excised, preserved lung. The FE model can also be used to calculate and visualize vibroacoustic pressure and motion inside the lung and its airways caused by the acoustic input. The effect of diffuse lung fibrosis and of a local tumor on the lung acoustic response is simulated and visualized using the FE model. In the future, this type of visualization can be compared and matched with experimentally obtained elastographic images to better quantify regional lung material properties to noninvasively diagnose and stage disease and response to treatment. PMID:25190415

  14. A comprehensive computational model of sound transmission through the porcine lung.

    PubMed

    Dai, Zoujun; Peng, Ying; Henry, Brian M; Mansy, Hansen A; Sandler, Richard H; Royston, Thomas J

    2014-09-01

    A comprehensive computational simulation model of sound transmission through the porcine lung is introduced and experimentally evaluated. This "subject-specific" model utilizes parenchymal and major airway geometry derived from x-ray CT images. The lung parenchyma is modeled as a poroviscoelastic material using Biot theory. A finite element (FE) mesh of the lung that includes airway detail is created and used in comsol FE software to simulate the vibroacoustic response of the lung to sound input at the trachea. The FE simulation model is validated by comparing simulation results to experimental measurements using scanning laser Doppler vibrometry on the surface of an excised, preserved lung. The FE model can also be used to calculate and visualize vibroacoustic pressure and motion inside the lung and its airways caused by the acoustic input. The effect of diffuse lung fibrosis and of a local tumor on the lung acoustic response is simulated and visualized using the FE model. In the future, this type of visualization can be compared and matched with experimentally obtained elastographic images to better quantify regional lung material properties to noninvasively diagnose and stage disease and response to treatment. PMID:25190415

  15. Development and application of a random lung model for dose calculations in radiotherapy

    NASA Astrophysics Data System (ADS)

    Liang, Liang

    Radiotherapy requires accurate dose calculations in the human body, especially in disease sites with large variations of electron density in neighboring tissues, such as the lung. Currently, the lung is modeled by a voxelized geometry interpolated from computed tomography (CT) scans to various resolutions. The simplest such voxelized lung, the atomic mix model, is a homogenized whole lung with a volume-averaged bulk density. However, according traditional transport theory, even the relatively fine CT voxelization of the lung is not valid, due to the extremely small mean free path (MFP) of the electrons. The purpose of this thesis is to study the impact of the lung's heterogeneities on dose calculations in lung treatment planning. We first extend the traditional atomic mix theory for charged particles by approximating the Boltzmann equation for electrons to its Fokker-Planck (FP) limit, and then applying a formal asymptotic analysis to the BFP equation. This analysis raises the length scale for homogenizing a heterogeneous medium from the electron mean free path (MFP) to the much larger electron transport MFP. Then, using the lung's anatomical data and our new atomic mix theory, we build a realistic 2 1/2-D random lung model. The dose distributions for representative realizations of the random lung model are compared to those from the atomic mix approximation of the random lung model, showing that significant perturbations may occur with small field sizes and large lung structures. We also apply our random lung model to a more realistic lung phantom and investigate the effect of CT resolutions on lung treatment planning. We show that, compared to the reference 1 x 1 mm2 CT resolution, a 2 x 2 mm2 CT resolution is sufficient to voxelize the lung, while significant deviations in dose can be observed with a larger 4 x 4 mm 2 CT resolution. We use the Monte Carlo method extensively in this thesis, to avoid systematic errors caused by inaccurate heterogeneity corrections

  16. Rat models of asthma and chronic obstructive lung disease.

    PubMed

    Martin, James G; Tamaoka, Meiyo

    2006-01-01

    The rat has been extensively used to model asthma and somewhat less extensively to model chronic obstructive pulmonary disease (COPD). The features of asthma that have been successfully modeled include allergen-induced airway constriction, eosinophilic inflammation and allergen-induced airway hyperresponsiveness. T-cell involvement has been directly demonstrated using adoptive transfer techniques. Both CD4+ and CD8+ T cells are activated in response to allergen challenge in the sensitized rat and express Thelper2 cytokines (IL-4, IL-5 and IL-13). Repeated allergen exposure causes airway remodeling. Dry gas hyperpnea challenge also evokes increases in lung resistance, allowing exercise-induced asthma to be modeled. COPD is modeled using elastase-induced parenchymal injury to mimic emphysema. Cigarette smoke-induced airspace enlargement occurs but requires months of cigarette exposure. Inflammation and fibrosis of peripheral airways is an important aspect of COPD that is less well modeled. Novel approaches to the treatment of COPD have been reported including treatments aimed at parenchymal regeneration. PMID:16337418

  17. RECONSTRUCTION OF A HUMAN LUNG MORPHOLOGY MODEL FROM MAGNETIC RESONANCE IMAGES

    EPA Science Inventory

    RATIONALE A description of lung morphological structure is necessary for modeling the deposition and fate of inhaled therapeutic aerosols. A morphological model of the lung boundary was generated from magnetic resonance (MR) images with the goal of creating a framework for anato...

  18. COMPUTER RECONSTRUCTION OF A HUMAN LUNG MORPHOLOGY MODEL FROM MAGNETIC RESONANCE (MR) IMAGES

    EPA Science Inventory


    A mathematical description of the morphological structure of the lung is necessary for modeling and analysis of the deposition of inhaled aerosols. A morphological model of the lung boundary was generated from magnetic resonance (MR) images, with the goal of creating a frame...

  19. Directional Multi-scale Modeling of High-Resolution Computed Tomography (HRCT) Lung Images for Diffuse Lung Disease Classification

    NASA Astrophysics Data System (ADS)

    Vo, Kiet T.; Sowmya, Arcot

    A directional multi-scale modeling scheme based on wavelet and contourlet transforms is employed to describe HRCT lung image textures for classifying four diffuse lung disease patterns: normal, emphysema, ground glass opacity (GGO) and honey-combing. Generalized Gaussian density parameters are used to represent the detail sub-band features obtained by wavelet and contourlet transforms. In addition, support vector machines (SVMs) with excellent performance in a variety of pattern classification problems are used as classifier. The method is tested on a collection of 89 slices from 38 patients, each slice of size 512x512, 16 bits/pixel in DICOM format. The dataset contains 70,000 ROIs of those slices marked by experienced radiologists. We employ this technique at different wavelet and contourlet transform scales for diffuse lung disease classification. The technique presented here has best overall sensitivity 93.40% and specificity 98.40%.

  20. Processes involved in the repair of injured airway epithelia.

    PubMed

    Tesfaigzi, Yohannes

    2003-01-01

    Recent studies have uncovered many aspects of the repair processes that follow airway epithelial injury. Although the repair process has common elements among various epithelia, such as the ones lining the airways, skin, and gut, there are differences based on their diverse functions. Whenever possible, similarities are pointed out that could help researchers further investigate their application to airway epithelia, although it would be beyond the scope of this review to cover the processes that may occur during the repair of all types of epithelia. In general, five major steps are involved in the recovery of airway epithelia from injury: 1) epithelial cells migrate to cover denuded areas within minutes, and certain proteins, such as the trefoil factor family proteins, are crucial to this process; 2) epithelial cells start to proliferate in order to replace injured cells and to differentiate to establish squamous or mucous cell metaplasia; 3) because more epithelial cells are present after proliferation, some of the cells must be discarded to restore the epithelium to the original condition; 4) once the cell numbers have been reduced to those found in unexposed individuals, the normal proportions of cell types are restored; 5) finally, studies from exposures of rats to ozone show that epithelial cells can adapt and develop a memory of the chronic exposure to which they were exposed. This adaptation allows the epithelium to respond quickly, thus minimizing further injury. Although the molecular mechanisms involved in these major steps of the recovery process are largely unknown, disruption of these steps clearly causes the permanent changes observed in diseases such as asthma, chronic bronchitis, and cancer; therefore, extensive research of these mechanisms may provide ideas for novel therapies. PMID:14626427

  1. Biology Based Lung Cancer Model for Chronic Low Radon Exposures

    SciTech Connect

    Truta-Popa, Lucia-Adina; Hofmann, Werner; Fakir, Hatim; Cosma, Constantin

    2008-08-07

    Low dose effects of alpha particles at the tissue level are characterized by the interaction of single alpha particles, affecting only a small fraction of the cells within that tissue. Alpha particle intersections of bronchial target cells during a given exposure period were simulated by an initiation-promotion model, formulated in terms of cellular hits within the cycle time of the cell (dose-rate) and then integrated over the whole exposure period (dose). For a given average number of cellular hits during the lifetime of bronchial cells, the actual number of single and multiple hits was selected from a Poisson distribution. While oncogenic transformation is interpreted as the primary initiation step, stimulated mitosis by killing adjacent cells is assumed to be the primary radiological promotion event. Analytical initiation and promotion functions were derived from experimental in vitro data on oncogenic transformation and cellular survival.To investigate the shape of the lung cancer risk function at chronic, low level exposures in more detail, additional biological factors describing the tissue response and operating specifically at low doses were incorporated into the initiation-promotion model. These mechanisms modifying the initial response at the cellular level were: adaptive response, genomic instability, induction of apoptosis by surrounding cells, and detrimental as well as protective bystander mechanisms. To quantify the effects of these mechanisms as functions of dose, analytical functions were derived from the experimental evidence presently available. Predictions of lung cancer risk, including these mechanisms, exhibit a distinct sublinear dose-response relationship at low exposures, particularly for very low exposure rates.

  2. Biology Based Lung Cancer Model for Chronic Low Radon Exposures

    NASA Astrophysics Data System (ADS)

    TruÅ£ǎ-Popa, Lucia-Adina; Hofmann, Werner; Fakir, Hatim; Cosma, Constantin

    2008-08-01

    Low dose effects of alpha particles at the tissue level are characterized by the interaction of single alpha particles, affecting only a small fraction of the cells within that tissue. Alpha particle intersections of bronchial target cells during a given exposure period were simulated by an initiation-promotion model, formulated in terms of cellular hits within the cycle time of the cell (dose-rate) and then integrated over the whole exposure period (dose). For a given average number of cellular hits during the lifetime of bronchial cells, the actual number of single and multiple hits was selected from a Poisson distribution. While oncogenic transformation is interpreted as the primary initiation step, stimulated mitosis by killing adjacent cells is assumed to be the primary radiological promotion event. Analytical initiation and promotion functions were derived from experimental in vitro data on oncogenic transformation and cellular survival. To investigate the shape of the lung cancer risk function at chronic, low level exposures in more detail, additional biological factors describing the tissue response and operating specifically at low doses were incorporated into the initiation-promotion model. These mechanisms modifying the initial response at the cellular level were: adaptive response, genomic instability, induction of apoptosis by surrounding cells, and detrimental as well as protective bystander mechanisms. To quantify the effects of these mechanisms as functions of dose, analytical functions were derived from the experimental evidence presently available. Predictions of lung cancer risk, including these mechanisms, exhibit a distinct sublinear dose-response relationship at low exposures, particularly for very low exposure rates.

  3. Identification and behavior of label-retaining cells in epithelia

    SciTech Connect

    Bickenbach, J.R.

    1982-01-01

    A subpopulation of stem cells has been demonstrated in several renewing tissues. Such cells have a slow cell cycle and provide differentiating cells during normal turnover and during regeneration of the tissue following damage. The presence of slowly-cycling cells in epithelia from regions of skin and oral mucosa was examined by labeling 10-day-old mice and 5-day-old hamsters with tritiated thymidine (/sup 3/H-TdR) and observing the rate at which label was diluted from the basal cells. Label was rapidly diluted by cell division in most cells but a small percentage of basal cells (label-retaining cells, LRCS) was found to retain label for up to ninety days. Electron microscopic autoradiography and ..beta..-glucuronidase histochemistry with autoradiography were used to distinguish slowly-cycling keratinocytes from Langerhans cells. Such findings of slowly-cycling keratinocytes in epithelia with the ability to proliferate in culture and with a direct relationship to patterns of tissue architecture suggest that LRCs in epithelia correspond to stem cells described in other continuously renewing tissues.

  4. Chloride and potassium channels in cystic fibrosis airway epithelia

    NASA Astrophysics Data System (ADS)

    Welsh, Michael J.; Liedtke, Carole M.

    1986-07-01

    Cystic fibrosis, the most common lethal genetic disease in Caucasians, is characterized by a decreased permeability in sweat gland duct and airway epithelia. In sweat duct epithelium, a decreased Cl- permeability accounts for the abnormally increased salt content of sweat1. In airway epithelia a decreased Cl- permeability, and possibly increased sodium absorption, may account for the abnormal respiratory tract fluid2,3. The Cl- impermeability has been localized to the apical membrane of cystic fibrosis airway epithelial cells4. The finding that hormonally regulated Cl- channels make the apical membrane Cl- permeable in normal airway epithelial cells5 suggested abnormal Cl- channel function in cystic fibrosis. Here we report that excised, cell-free patches of membrane from cystic fibrosis epithelial cells contain Cl- channels that have the same conductive properties as Cl- channels from normal cells. However, Cl- channels from cystic fibrosis cells did not open when they were attached to the cell. These findings suggest defective regulation of Cl- channels in cystic fibrosis epithelia; to begin to address this issue, we performed two studies. First, we found that isoprenaline, which stimulates Cl- secretion, increases cellular levels of cyclic AMP in a similar manner in cystic fibrosis and non-cystic fibrosis epithelial cells. Second, we show that adrenergic agonists open calcium-activated potassium channels, indirectly suggesting that calcium-dependent stimulus-response coupling is intact in cystic fibrosis. These data suggest defective regulation of Cl- channels at a site distal to cAMP accumulation.

  5. Sensitivity of tumor motion simulation accuracy to lung biomechanical modeling approaches and parameters

    NASA Astrophysics Data System (ADS)

    Nasehi Tehrani, Joubin; Yang, Yin; Werner, Rene; Lu, Wei; Low, Daniel; Guo, Xiaohu; Wang, Jing

    2015-11-01

    Finite element analysis (FEA)-based biomechanical modeling can be used to predict lung respiratory motion. In this technique, elastic models and biomechanical parameters are two important factors that determine modeling accuracy. We systematically evaluated the effects of lung and lung tumor biomechanical modeling approaches and related parameters to improve the accuracy of motion simulation of lung tumor center of mass (TCM) displacements. Experiments were conducted with four-dimensional computed tomography (4D-CT). A Quasi-Newton FEA was performed to simulate lung and related tumor displacements between end-expiration (phase 50%) and other respiration phases (0%, 10%, 20%, 30%, and 40%). Both linear isotropic and non-linear hyperelastic materials, including the neo-Hookean compressible and uncoupled Mooney-Rivlin models, were used to create a finite element model (FEM) of lung and tumors. Lung surface displacement vector fields (SDVFs) were obtained by registering the 50% phase CT to other respiration phases, using the non-rigid demons registration algorithm. The obtained SDVFs were used as lung surface displacement boundary conditions in FEM. The sensitivity of TCM displacement to lung and tumor biomechanical parameters was assessed in eight patients for all three models. Patient-specific optimal parameters were estimated by minimizing the TCM motion simulation errors between phase 50% and phase 0%. The uncoupled Mooney-Rivlin material model showed the highest TCM motion simulation accuracy. The average TCM motion simulation absolute errors for the Mooney-Rivlin material model along left-right, anterior-posterior, and superior-inferior directions were 0.80 mm, 0.86 mm, and 1.51 mm, respectively. The proposed strategy provides a reliable method to estimate patient-specific biomechanical parameters in FEM for lung tumor motion simulation.

  6. Sensitivity of tumor motion simulation accuracy to lung biomechanical modeling approaches and parameters.

    PubMed

    Tehrani, Joubin Nasehi; Yang, Yin; Werner, Rene; Lu, Wei; Low, Daniel; Guo, Xiaohu; Wang, Jing

    2015-11-21

    Finite element analysis (FEA)-based biomechanical modeling can be used to predict lung respiratory motion. In this technique, elastic models and biomechanical parameters are two important factors that determine modeling accuracy. We systematically evaluated the effects of lung and lung tumor biomechanical modeling approaches and related parameters to improve the accuracy of motion simulation of lung tumor center of mass (TCM) displacements. Experiments were conducted with four-dimensional computed tomography (4D-CT). A Quasi-Newton FEA was performed to simulate lung and related tumor displacements between end-expiration (phase 50%) and other respiration phases (0%, 10%, 20%, 30%, and 40%). Both linear isotropic and non-linear hyperelastic materials, including the neo-Hookean compressible and uncoupled Mooney-Rivlin models, were used to create a finite element model (FEM) of lung and tumors. Lung surface displacement vector fields (SDVFs) were obtained by registering the 50% phase CT to other respiration phases, using the non-rigid demons registration algorithm. The obtained SDVFs were used as lung surface displacement boundary conditions in FEM. The sensitivity of TCM displacement to lung and tumor biomechanical parameters was assessed in eight patients for all three models. Patient-specific optimal parameters were estimated by minimizing the TCM motion simulation errors between phase 50% and phase 0%. The uncoupled Mooney-Rivlin material model showed the highest TCM motion simulation accuracy. The average TCM motion simulation absolute errors for the Mooney-Rivlin material model along left-right, anterior-posterior, and superior-inferior directions were 0.80 mm, 0.86 mm, and 1.51 mm, respectively. The proposed strategy provides a reliable method to estimate patient-specific biomechanical parameters in FEM for lung tumor motion simulation. PMID:26531324

  7. Assessing model uncertainty using hexavalent chromium and lung cancer mortality as an example [Abstract 2015

    EPA Science Inventory

    Introduction: The National Research Council recommended quantitative evaluation of uncertainty in effect estimates for risk assessment. This analysis considers uncertainty across model forms and model parameterizations with hexavalent chromium [Cr(VI)] and lung cancer mortality a...

  8. An anatomically realistic lung model for Monte Carlo-based dose calculations

    SciTech Connect

    Liang Liang; Larsen, Edward W.; Chetty, Indrin J.

    2007-03-15

    Treatment planning for disease sites with large variations of electron density in neighboring tissues requires an accurate description of the geometry. This self-evident statement is especially true for the lung, a highly complex organ having structures with a wide range of sizes that range from about 10{sup -4} to 1 cm. In treatment planning, the lung is commonly modeled by a voxelized geometry obtained using computed tomography (CT) data at various resolutions. The simplest such model, which is often used for QA and validation work, is the atomic mix or mean density model, in which the entire lung is homogenized and given a mean (volume-averaged) density. The purpose of this paper is (i) to describe a new heterogeneous random lung model, which is based on morphological data of the human lung, and (ii) use this model to assess the differences in dose calculations between an actual lung (as represented by our model) and a mean density (homogenized) lung. Eventually, we plan to use the random lung model to assess the accuracy of CT-based treatment plans of the lung. For this paper, we have used Monte Carlo methods to make accurate comparisons between dose calculations for the random lung model and the mean density model. For four realizations of the random lung model, we used a single photon beam, with two different energies (6 and 18 MV) and four field sizes (1x1, 5x5, 10x10, and 20x20 cm{sup 2}). We found a maximum difference of 34% of D{sub max} with the 1x1, 18 MV beam along the central axis (CAX). A ''shadow'' region distal to the lung, with dose reduction up to 7% of D{sub max}, exists for the same realization. The dose perturbations decrease for larger field sizes, but the magnitude of the differences in the shadow region is nearly independent of the field size. We also observe that, compared to the mean density model, the random structures inside the heterogeneous lung can alter the shape of the isodose lines, leading to a broadening or shrinking of the

  9. Differential effects of cyclic and constant stress on ATP release and mucociliary transport by human airway epithelia.

    PubMed

    Button, Brian; Picher, Maryse; Boucher, Richard C

    2007-04-15

    In the lungs, the first line of defence against bacterial infection is the thin layer of airway surface liquid (ASL) lining the airway surface. The superficial airway epithelium exhibits complex regulatory pathways that blend ion transport to adjust ASL volume to maintain proper mucociliary clearance (MCC). We hypothesized that stresses generated by airflow and transmural pressures during breathing govern ASL volume by regulating the rate of epithelial ATP release. Luminal ATP, via interactions with apical membrane P2-purinoceptors, regulates the balance of active ion secretion versus absorption to maintain ASL volume at optimal levels for MCC. In this study we tested the hypothesis that cyclic compressive stress (CCS), mimicking normal tidal breathing, regulates ASL volume in airway epithelia. Polarized tracheobronchial epithelial cultures from normal and cystic fibrosis (CF) subjects responded to a range of CCS by increasing the rate of ATP release. In normal airway epithelia, the CCS-induced increase in ASL ATP concentration was sufficient to induce purinoceptor-mediated increases in ASL height and MCC, via inhibition of epithelial Na(+)-channel-mediated Na(+) absorption and stimulation of Cl(-) secretion through CFTR and the Ca(2+)-activated chloride channels. In contrast, static, non-oscillatory stress did not stimulate ATP release, ion transport or MCC, emphasizing the importance of rhythmic mechanical stress for airway defence. In CF airway cultures, which exhibit basal ASL depletion, CCS was partially effective, producing less ASL volume secretion than in normal cultures, but a level sufficient to restore MCC. The present data suggest that CCS may (1) regulate ASL volume in the normal lung and (2) improve clearance in the lungs of CF patients, potentially explaining the beneficial role of exercise in lung defence. PMID:17317749

  10. Prolactin and teleost ionocytes: new insights into cellular and molecular targets of prolactin in vertebrate epithelia

    USGS Publications Warehouse

    Breves, Jason P.; McCormick, Stephen D.; Karlstrom, Rolf O.

    2014-01-01

    The peptide hormone prolactin is a functionally versatile hormone produced by the vertebrate pituitary. Comparative studies over the last six decades have revealed that a conserved function for prolactin across vertebrates is the regulation of ion and water transport in a variety of tissues including those responsible for whole-organism ion homeostasis. In teleost fishes, prolactin was identified as the “freshwater-adapting hormone”, promoting ion-conserving and water-secreting processes by acting on the gill, kidney, gut and urinary bladder. In mammals, prolactin is known to regulate renal, intestinal, mammary and amniotic epithelia, with dysfunction linked to hypogonadism, infertility, and metabolic disorders. Until recently, our understanding of the cellular mechanisms of prolactin action in fishes has been hampered by a paucity of molecular tools to define and study ionocytes, specialized cells that control active ion transport across branchial and epidermal epithelia. Here we review work in teleost models indicating that prolactin regulates ion balance through action on ion transporters, tight-junction proteins, and water channels in ionocytes, and discuss recent advances in our understanding of ionocyte function in the genetically and embryonically accessible zebrafish (Danio rerio). Given the high degree of evolutionary conservation in endocrine and osmoregulatory systems, these studies in teleost models are contributing novel mechanistic insight into how prolactin participates in the development, function, and dysfunction of osmoregulatory systems across the vertebrate lineage.

  11. Prolactin and teleost ionocytes: new insights into cellular and molecular targets of prolactin in vertebrate epithelia

    PubMed Central

    Breves, Jason P.; McCormick, Stephen D.; Karlstrom, Rolf O.

    2014-01-01

    The peptide hormone prolactin is a functionally versatile hormone produced by the vertebrate pituitary. Comparative studies over the last six decades have revealed that a conserved function for prolactin across vertebrates is the regulation of ion and water transport in a variety of tissues including those responsible for whole-organism ion homeostasis. In teleost fishes, prolactin was identified as the “freshwater-adapting hormone”, promoting ion-conserving and water-secreting processes by acting on the gill, kidney, gut and urinary bladder. In mammals, prolactin is known to regulate renal, intestinal, mammary and amniotic epithelia, with dysfunction linked to hypogonadism, infertility, and metabolic disorders. Until recently, our understanding of the cellular mechanisms of prolactin action in fishes has been hampered by a paucity of molecular tools to define and study ionocytes, specialized cells that control active ion transport across branchial and epidermal epithelia. Here we review work in teleost models indicating that prolactin regulates ion balance through action on ion transporters, tight-junction proteins, and water channels in ionocytes, and discuss recent advances in our understanding of ionocyte function in the genetically and embryonically accessible zebrafish (Danio rerio). Given the high degree of evolutionary conservation in endocrine and osmoregulatory systems, these studies in teleost models are contributing novel mechanistic insight into how prolactin participates in the development, function, and dysfunction of osmoregulatory systems across the vertebrate lineage. PMID:24434597

  12. Prolactin and teleost ionocytes: new insights into cellular and molecular targets of prolactin in vertebrate epithelia.

    PubMed

    Breves, Jason P; McCormick, Stephen D; Karlstrom, Rolf O

    2014-07-01

    The peptide hormone prolactin is a functionally versatile hormone produced by the vertebrate pituitary. Comparative studies over the last six decades have revealed that a conserved function for prolactin across vertebrates is the regulation of ion and water transport in a variety of tissues including those responsible for whole-organism ion homeostasis. In teleost fishes, prolactin was identified as the "freshwater-adapting hormone", promoting ion-conserving and water-secreting processes by acting on the gill, kidney, gut and urinary bladder. In mammals, prolactin is known to regulate renal, intestinal, mammary and amniotic epithelia, with dysfunction linked to hypogonadism, infertility, and metabolic disorders. Until recently, our understanding of the cellular mechanisms of prolactin action in fishes has been hampered by a paucity of molecular tools to define and study ionocytes, specialized cells that control active ion transport across branchial and epidermal epithelia. Here we review work in teleost models indicating that prolactin regulates ion balance through action on ion transporters, tight-junction proteins, and water channels in ionocytes, and discuss recent advances in our understanding of ionocyte function in the genetically and embryonically accessible zebrafish (Danio rerio). Given the high degree of evolutionary conservation in endocrine and osmoregulatory systems, these studies in teleost models are contributing novel mechanistic insight into how prolactin participates in the development, function, and dysfunction of osmoregulatory systems across the vertebrate lineage. PMID:24434597

  13. A multiscale MDCT image-based breathing lung model with time-varying regional ventilation.

    PubMed

    Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A; Tawhai, Merryn H; Lin, Ching-Long

    2013-07-01

    A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C 1 continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung. PMID:23794749

  14. A multiscale MDCT image-based breathing lung model with time-varying regional ventilation

    SciTech Connect

    Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A.; Tawhai, Merryn H.; Lin, Ching-Long

    2013-07-01

    A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C{sub 1} continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung.

  15. A multiscale MDCT image-based breathing lung model with time-varying regional ventilation

    PubMed Central

    Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A.; Tawhai, Merryn H.; Lin, Ching-Long

    2012-01-01

    A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C1 continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung. PMID:23794749

  16. Dry Lung as a Physical Model in Studies of Aerosol Deposition.

    PubMed

    Morozov, Victor N; Kanev, Igor L

    2015-10-01

    A new physical model was developed to evaluate the deposition of micro- and nanoaerosol particles (NAPs) into the lungs as a function of size and charges. The model was manufactured of a dry, inflated swine lung produced by Nasco company (Fort Atkinson, WI). The dry lung was cut into two lobes and a conductive tube was glued into the bronchial tube. The upper 1-2-mm-thick layer of the lung lobe was removed with a razor blade to expose the alveoli. The lobe was further enclosed into a plastic bag and placed within a metalized plastic box. The probability of aerosol deposition was calculated by comparing the size distribution of NAPs passed through the lung with that of control, where aerosol passed through a box bypassing the lung. Using this new lung model, it was demonstrated that charged NAPs are deposited inside the lung substantially more efficiently than neutral ones. It was also demonstrated that deposition of neutral NAPs well fits prediction of the Multiple-Path Particle Dosimetry (MPPD) model developed by the Applied Research Associates, Inc. (ARA). PMID:26267596

  17. Ovine pulmonary adenocarcinoma: a large animal model for human lung cancer.

    PubMed

    Youssef, Gehad; Wallace, William A H; Dagleish, Mark P; Cousens, Chris; Griffiths, David J

    2015-01-01

    Lung cancer is the leading cause of cancer deaths worldwide. Recent progress in understanding the molecular pathogenesis of this disease has resulted in novel therapeutic strategies targeting specific groups of patients. Further studies are required to provide additional advances in diagnosis and treatment. Animal models are valuable tools for studying oncogenesis in lung cancer, particularly during the early stages of disease where tissues are rarely available from human cases. Mice have traditionally been used for studying lung cancer in vivo, and a variety of spontaneous and transgenic models are available. However, it is recognized that other species may also be informative for studies of cancer. Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring lung cancer of sheep caused by retrovirus infection and has several features in common with adenocarcinoma of humans, including a similar histological appearance and activation of common cell signaling pathways. Additionally, the size and organization of human lungs are much closer to those of sheep lungs than to those of mice, which facilitates experimental approaches in sheep that are not available in mice. Thus OPA presents opportunities for studying lung tumor development that can complement conventional murine models. Here we describe the potential applications of OPA as a model for human lung adenocarcinoma with an emphasis on the various in vivo and in vitro experimental systems available. PMID:25991702

  18. COMPUTER SIMULATIONS OF LUNG AIRWAY STRUCTURES USING DATA-DRIVEN SURFACE MODELING TECHNIQUES

    EPA Science Inventory

    ABSTRACT

    Knowledge of human lung morphology is a subject critical to many areas of medicine. The visualization of lung structures naturally lends itself to computer graphics modeling due to the large number of airways involved and the complexities of the branching systems...

  19. The Lung Physiome: merging imaging-based measures with predictive computational models of structure and function

    PubMed Central

    Tawhai, Merryn H; Hoffman, Eric A; Lin, Ching-Long

    2009-01-01

    Global measurements of the lung provided by standard pulmonary function tests do not give insight into the regional basis of lung function and lung disease. Advances in imaging methodologies, computer technologies, and subject-specific simulations are creating new opportunities for studying structure-function relationships in the lung through multi-disciplinary research. The digital Human Lung Atlas is an imaging-based resource compiled from male and female subjects spanning several decades of age. The Atlas comprises both structural and functional measures, and includes computational models derived to match individual subjects for personalized prediction of function. The computational models in the Atlas form part of the Lung Physiome project, which is an international effort to develop integrative models of lung function at all levels of biological organization. The computational models provide mechanistic interpretation of imaging measures; the Atlas provides structural data upon which to base model geometry, and functional data against which to test hypotheses. The example of simulating air flow on a subject-specific basis is considered. Methods for deriving multi-scale models of the airway geometry for individual subjects in the Atlas are outlined, and methods for modeling turbulent flows in the airway are reviewed. PMID:20835982

  20. The Implantable Pediatric Artificial Lung: Interim Report on the Development of an End-Stage Lung Failure Model

    PubMed Central

    Alghanem, Fares; Davis, Ryan P.; Bryner, Benjamin S.; Hoffman, Hayley R.; Trahanas, John; Cornell, Marie; Rojas-Peña, Alvaro; Bartlett, Robert H.; Hirschl, Ronald B.

    2015-01-01

    An implantable pediatric artificial lung (PAL) may serve as a bridge to lung transplantation for children with end-stage lung failure (ESLF); however, an animal model of pediatric lung failure is needed to evaluate a PAL’s efficacy before it can enter clinical trials. The objective of this study was to assess ligation of the right pulmonary artery (rPA) as a model for pediatric ESLF. Seven 20-30kg lambs underwent rPA ligation and were recovered and monitored for up to 4 days. Intraoperatively, rPA ligation significantly increased physiologic deadspace fraction (Vd/Vt: baseline=48.6±5.7%, rPA ligation=60.1±5.2%, p=0.012), mean pulmonary arterial pressure (mPPA: baseline=17.4±2.2mmHg, rPA ligation=28.5±5.2mmHg, p<0.001), and arterial partial pressure of carbon dioxide (PaCO2: baseline=40.4±9.3mmHg, rPA ligation=57.3±12.7mmHg, p=0.026). Of the 7 lambs, 3 were unable to be weaned from mechanical ventilation post-operatively, 3 were successfully weaned but suffered cardiorespiratory failure within 4 days, and 1 survived all 4 days. All 4 animals that were successfully weaned from mechanical ventilation had persistent pulmonary hypertension (mPPA=28.6±2.2mmHg) and remained tachypneic (respiratory rate=63±21min−1). Three of the 4 recovered lambs required supplemental oxygen. We conclude that rPA ligation creates the physiologic derangements commonly seen in pediatric end-stage lung failure and may be suitable for testing and implanting a PAL. PMID:25905495

  1. The effects of smoking on the developing lung: insights from a biologic model for lung development, homeostasis, and repair.

    PubMed

    Rehan, Virender K; Asotra, Kamlesh; Torday, John S

    2009-01-01

    There is extensive epidemiologic and experimental evidence from both animal and human studies that demonstrates detrimental long-term pulmonary outcomes in the offspring of mothers who smoke during pregnancy. However, the molecular mechanisms underlying these associations are not understood. Therefore, it is not surprising that that there is no effective intervention to prevent the damaging effects of perinatal smoke exposure. Using a biologic model of lung development, homeostasis, and repair, we have determined that in utero nicotine exposure disrupts specific molecular paracrine communications between epithelium and interstitium that are driven by parathyroid hormone-related protein and peroxisome proliferator-activated receptor (PPAR)gamma, resulting in transdifferentiation of lung lipofibroblasts to myofibroblasts, i.e., the conversion of the lipofibroblast phenotype to a cell type that is not conducive to alveolar homeostasis, and is the cellular hallmark of chronic lung disease, including asthma. Furthermore, we have shown that by molecularly targeting PPAR gamma expression, nicotine-induced lung injury can not only be significantly averted, it can also be reverted. The concept outlined by us differs from the traditional paradigm of teratogenic and toxicological effects of tobacco smoke that has been proposed in the past. We have argued that since nicotine alters the normal homeostatic epithelial-mesenchymal paracrine signaling in the developing alveolus, rather than causing totally disruptive structural changes, it offers a unique opportunity to prevent, halt, and/or reverse this process through targeted molecular manipulations. PMID:19641967

  2. Cultured corneal epithelia for ocular surface disease.

    PubMed Central

    Schwab, I R

    1999-01-01

    PURPOSE: To evaluate the potential efficacy for autologous and allogeneic expanded corneal epithelial cell transplants derived from harvested limbal corneal epithelial stem cells cultured in vitro for the management of ocular surface disease. METHODS: Human Subjects. Of the 19 human subjects included, 18 (20 procedures) underwent in vitro cultured corneal epithelial cell transplants using various carriers for the epithelial cells to determine the most efficacious approach. Sixteen patients (18 procedures on 17 eyes) received autologous transplants, and 2 patients (1 procedure each) received allogeneic sibling grafts. The presumed corneal epithelial stem cells from 1 patient did not grow in vitro. The carriers for the expanded corneal epithelial cells included corneal stroma, type 1 collagen (Vitrogen), soft contact lenses, collagen shields, and amniotic membrane for the autologous grafts and only amniotic membrane for the allogeneic sibling grafts. Histologic confirmation was reviewed on selected donor grafts. Amniotic membrane as carrier. Further studies were made to determine whether amniotic membrane might be the best carrier for the expanding corneal epithelial cells. Seventeen different combinations of tryspinization, sonication, scraping, and washing were studied to find the simplest, most effective method for removing the amniotic epithelium while still preserving the histologic appearance of the basement membrane of the amnion. Presumed corneal epithelial stem cells were harvested and expanded in vitro and applied to the amniotic membrane to create a composite graft. Thus, the composite graft consisted of the amniotic membrane from which the original epithelium had been removed without significant histologic damage to the basement membrane, and the expanded corneal epithelial stem cells, which had been applied to and had successfully adhered to the denuded amniotic membrane. Animal model. Twelve rabbits had the ocular surface of 1 eye damaged in a standard

  3. Response and resistance to NF-κB inhibitors in mouse models of lung adenocarcinoma

    PubMed Central

    Xue, Wen; Meylan, Etienne; Oliver, Trudy G.; Feldser, David M.; Winslow, Monte M.; Bronson, Roderick; Jacks, Tyler

    2011-01-01

    Lung adenocarcinoma is a frequently diagnosed cancer type and a leading cause of cancer death worldwide. We recently demonstrated in an autochthonous mouse model of this disease that genetic inhibition of the NF-κB pathway affects both the initiation and maintenance of lung cancer, identifying this pathway as a promising therapeutic target. In this study, we tested the efficacy of small molecule NF-κB inhibitors in mouse models of lung cancer. In murine lung adenocarcinoma cell lines with high NF-κB activity, the proteasome inhibitor Bortezomib efficiently reduced nuclear p65, repressed NF-κB target genes and rapidly induced apoptosis. Bortezomib also induced lung tumor regression in vivo and prolonged the survival of tumor bearing KrasLSL-G12D/wt;p53flox/flox mice. In contrast, KrasG12D/wt lung tumors, which have low levels of nuclear NF-κB, do not respond to Bortezomib, suggesting that nuclear NF-κB may be a biomarker to predict treatment response to drugs of this class. Following repeated treatment, initially sensitive lung tumors became resistant to Bortezomib. A second NF-κB inhibitor, Bay-117082, showed similar therapeutic efficacy and acquired-resistance in mice. Our results using preclinical mouse models support the NF-κB pathway as a potential therapeutic target for a defined subset of lung adenocarcinoma. PMID:21874163

  4. Topological Progression in Proliferating Epithelia Is Driven by a Unique Variation in Polygon Distribution

    PubMed Central

    Sánchez-Gutiérrez, Daniel; Sáez, Aurora; Pascual, Alberto; Escudero, Luis M.

    2013-01-01

    Morphogenesis is consequence of lots of small coordinated variations that occur during development. In proliferating stages, tissue growth is coupled to changes in shape and organization. A number of studies have analyzed the topological properties of proliferating epithelia using the Drosophila wing disc as a model. These works are based in the existence of a fixed distribution of these epithelial cells according to their number of sides. Cell division, cell rearrangements or a combination of both mechanisms have been proposed to be responsible for this polygonal assembling. Here, we have used different system biology methods to compare images from two close proliferative stages that present high morphological similarity. This approach enables us to search for traces of epithelial organization. First, we show that geometrical and network characteristics of individual cells are mainly dependent on their number of sides. Second, we find a significant divergence between the distribution of polygons in epithelia from mid-third instar larva versus early prepupa. We show that this alteration propagates into changes in epithelial organization. Remarkably, only the variation in polygon distribution driven by morphogenesis leads to progression in epithelial organization. In addition, we identify the relevant features that characterize these rearrangements. Our results reveal signs of epithelial homogenization during the growing phase, before the planar cell polarity pathway leads to the hexagonal packing of the epithelium during pupal stages. PMID:24223910

  5. Aurora Kinases Phosphorylate Lgl to Induce Mitotic Spindle Orientation in Drosophila Epithelia

    PubMed Central

    Bell, Graham P.; Fletcher, Georgina C.; Brain, Ruth; Thompson, Barry J.

    2015-01-01

    Summary The Lethal giant larvae (Lgl) protein was discovered in Drosophila as a tumor suppressor in both neural stem cells (neuroblasts) and epithelia. In neuroblasts, Lgl relocalizes to the cytoplasm at mitosis, an event attributed to phosphorylation by mitotically activated aPKC kinase and thought to promote asymmetric cell division. Here we show that Lgl also relocalizes to the cytoplasm at mitosis in epithelial cells, which divide symmetrically. The Aurora A and B kinases directly phosphorylate Lgl to promote its mitotic relocalization, whereas aPKC kinase activity is required only for polarization of Lgl. A form of Lgl that is a substrate for aPKC, but not Aurora kinases, can restore cell polarity in lgl mutants but reveals defects in mitotic spindle orientation in epithelia. We propose that removal of Lgl from the plasma membrane at mitosis allows Pins/LGN to bind Dlg and thus orient the spindle in the plane of the epithelium. Our findings suggest a revised model for Lgl regulation and function in both symmetric and asymmetric cell divisions. PMID:25484300

  6. p21 suppresses inflammation and tumorigenesis on pRB-deficient stratified epithelia

    PubMed Central

    Garín, Marina; Ruiz, Sergio; Santos, Mirentxu; Lorz, Corina; García-Escudero, Ramón; Martínez-Fernández, Mónica; Bravo, Ana; Fernández-Capetillo, Oscar; Segrelles, Carmen; Paramio, Jesús M

    2016-01-01

    The retinoblastoma gene product (pRb) controls proliferation and differentiation processes in stratified epithelia. Importantly, an in contrast to other tissues, Rb deficiency does not lead to spontaneous skin tumor formation. As the cyclin dependent kinase inhibitor p21 regulates proliferation and differentiation in the absence of pRb, we analyzed the consequences of deleting p21 in pRb-ablated stratified epithelia (hereafter pRbΔEpi;p21-/-). These mice display an enhancement of the phenotypic abnormalities observed in pRbΔEpi animals, indicating that p21 partially compensates pRb absence. Remarkably, pRbΔEpi;p21-/- mice show an acute skin inflammatory phenotype and develop spontaneous epithelial tumors, particularly affecting tongue and oral tissues. Biochemical analyses and transcriptome studies reveal changes affecting multiple pathways, including DNA damage and p53-dependent signaling responses. Comparative metagenomic analyses, together with the histopathological profiles, indicate that these mice constitute a faithful model for human head and neck squamous cell carcinomas. Collectively, our findings demonstrate that p21, in conjunction with pRb, plays a central role in regulating multiple epithelial processes and orchestrating specific tumor suppressor functions. PMID:24121270

  7. Dynamics of Surfactant Liquid Plugs at Bifurcating Lung Airway Models

    NASA Astrophysics Data System (ADS)

    Tavana, Hossein

    2013-11-01

    A surfactant liquid plug forms in the trachea during surfactant replacement therapy (SRT) of premature babies. Under air pressure, the plug propagates downstream and continuously divides into smaller daughter plugs at continuously branching lung airways. Propagating plugs deposit a thin film on airway walls to reduce surface tension and facilitate breathing. The effectiveness of SRT greatly depends on the final distribution of instilled surfactant within airways. To understand this process, we investigate dynamics of splitting of surfactant plugs in engineered bifurcating airway models. A liquid plug is instilled in the parent tube to propagate and split at the bifurcation. A split ratio, R, is defined as the ratio of daughter plug lengths in the top and bottom daughter airway tubes and studied as a function of the 3D orientation of airways and different flow conditions. For a given Capillary number (Ca), orienting airways farther away from a horizontal position reduced R due to the flow of a larger volume into the gravitationally favored daughter airway. At each orientation, R increased with 0.0005 < Ca < 0.05. This effect diminished by decrease in airways diameter. This approach will help elucidate surfactant distribution in airways and develop effective SRT strategies.

  8. COMPUTER MODEL OF HUMAN LUNG MORPHOLOGY TO COMPLEMENT SPECT ANALYSES

    EPA Science Inventory

    Aerosol therapy protocols could be improved if inhaled pharmacologic drugs were selectively deposited within the human lung. he targeted delivery to specific sites, such as receptors and sensitive airway cells, would enhance the efficacies of airborne pharmaceuticals. he high res...

  9. Longitudinal micro-CT provides biomarkers of lung disease that can be used to assess the effect of therapy in preclinical mouse models, and reveal compensatory changes in lung volume

    PubMed Central

    Vande Velde, Greetje; Poelmans, Jennifer; De Langhe, Ellen; Hillen, Amy; Vanoirbeek, Jeroen; Himmelreich, Uwe; Lories, Rik J.

    2016-01-01

    ABSTRACT In vivo lung micro-computed tomography (micro-CT) is being increasingly embraced in pulmonary research because it provides longitudinal information on dynamic disease processes in a field in which ex vivo assessment of experimental disease models is still the gold standard. To optimize the quantitative monitoring of progression and therapy of lung diseases, we evaluated longitudinal changes in four different micro-CT-derived biomarkers [aerated lung volume, lung tissue (including lesions) volume, total lung volume and mean lung density], describing normal development, lung infections, inflammation, fibrosis and therapy. Free-breathing mice underwent micro-CT before and repeatedly after induction of lung disease (bleomycin-induced fibrosis, invasive pulmonary aspergillosis, pulmonary cryptococcosis) and therapy (imatinib). The four lung biomarkers were quantified. After the last time point, we performed pulmonary function tests and isolated the lungs for histology. None of the biomarkers remained stable during longitudinal follow-up of adult healthy mouse lungs, implying that biomarkers should be compared with age-matched controls upon intervention. Early inflammation and progressive fibrosis led to a substantial increase in total lung volume, which affects the interpretation of aerated lung volume, tissue volume and mean lung density measures. Upon treatment of fibrotic lung disease, the improvement in aerated lung volume and function was not accompanied by a normalization of the increased total lung volume. Significantly enlarged lungs were also present in models of rapidly and slowly progressing lung infections. The data suggest that total lung volume changes could partly reflect a compensatory mechanism that occurs during disease progression in mice. Our findings underscore the importance of quantifying total lung volume in addition to aerated lung or lesion volumes to accurately document growth and potential compensatory mechanisms in mouse models of

  10. Human Organotypic Lung Tumor Models: Suitable For Preclinical 18F-FDG PET-Imaging

    PubMed Central

    Fecher, David; Hofmann, Elisabeth; Buck, Andreas; Bundschuh, Ralph; Nietzer, Sarah; Dandekar, Gudrun; Walles, Thorsten; Walles, Heike; Lückerath, Katharina; Steinke, Maria

    2016-01-01

    Development of predictable in vitro tumor models is a challenging task due to the enormous complexity of tumors in vivo. The closer the resemblance of these models to human tumor characteristics, the more suitable they are for drug-development and –testing. In the present study, we generated a complex 3D lung tumor test system based on acellular rat lungs. A decellularization protocol was established preserving the architecture, important ECM components and the basement membrane of the lung. Human lung tumor cells cultured on the scaffold formed cluster and exhibited an up-regulation of the carcinoma-associated marker mucin1 as well as a reduced proliferation rate compared to respective 2D culture. Additionally, employing functional imaging with 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) these tumor cell cluster could be detected and tracked over time. This approach allowed monitoring of a targeted tyrosine kinase inhibitor treatment in the in vitro lung tumor model non-destructively. Surprisingly, FDG-PET assessment of single tumor cell cluster on the same scaffold exhibited differences in their response to therapy, indicating heterogeneity in the lung tumor model. In conclusion, our complex lung tumor test system features important characteristics of tumors and its microenvironment and allows monitoring of tumor growth and -metabolism in combination with functional imaging. In longitudinal studies, new therapeutic approaches and their long-term effects can be evaluated to adapt treatment regimes in future. PMID:27501455

  11. Human Organotypic Lung Tumor Models: Suitable For Preclinical 18F-FDG PET-Imaging.

    PubMed

    Fecher, David; Hofmann, Elisabeth; Buck, Andreas; Bundschuh, Ralph; Nietzer, Sarah; Dandekar, Gudrun; Walles, Thorsten; Walles, Heike; Lückerath, Katharina; Steinke, Maria

    2016-01-01

    Development of predictable in vitro tumor models is a challenging task due to the enormous complexity of tumors in vivo. The closer the resemblance of these models to human tumor characteristics, the more suitable they are for drug-development and -testing. In the present study, we generated a complex 3D lung tumor test system based on acellular rat lungs. A decellularization protocol was established preserving the architecture, important ECM components and the basement membrane of the lung. Human lung tumor cells cultured on the scaffold formed cluster and exhibited an up-regulation of the carcinoma-associated marker mucin1 as well as a reduced proliferation rate compared to respective 2D culture. Additionally, employing functional imaging with 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) these tumor cell cluster could be detected and tracked over time. This approach allowed monitoring of a targeted tyrosine kinase inhibitor treatment in the in vitro lung tumor model non-destructively. Surprisingly, FDG-PET assessment of single tumor cell cluster on the same scaffold exhibited differences in their response to therapy, indicating heterogeneity in the lung tumor model. In conclusion, our complex lung tumor test system features important characteristics of tumors and its microenvironment and allows monitoring of tumor growth and -metabolism in combination with functional imaging. In longitudinal studies, new therapeutic approaches and their long-term effects can be evaluated to adapt treatment regimes in future. PMID:27501455

  12. The Audible Human Project: Modeling Sound Transmission in the Lungs and Torso

    NASA Astrophysics Data System (ADS)

    Dai, Zoujun

    Auscultation has been used qualitatively by physicians for hundreds of years to aid in the monitoring and diagnosis of pulmonary diseases. Alterations in the structure and function of the pulmonary system that occur in disease or injury often give rise to measurable changes in lung sound production and transmission. Numerous acoustic measurements have revealed the differences of breath sounds and transmitted sounds in the lung under normal and pathological conditions. Compared to the extensive cataloging of lung sound measurements, the mechanism of sound transmission in the pulmonary system and how it changes with alterations of lung structural and material properties has received less attention. A better understanding of sound transmission and how it is altered by injury and disease might improve interpretation of lung sound measurements, including new lung imaging modalities that are based on an array measurement of the acoustic field on the torso surface via contact sensors or are based on a 3-dimensional measurement of the acoustic field throughout the lungs and torso using magnetic resonance elastography. A long-term goal of the Audible Human Project (AHP ) is to develop a computational acoustic model that would accurately simulate generation, transmission and noninvasive measurement of sound and vibration within the pulmonary system and torso caused by both internal (e.g. respiratory function) and external (e.g. palpation) sources. The goals of this dissertation research, fitting within the scope of the AHP, are to develop specific improved theoretical understandings, computational algorithms and experimental methods aimed at transmission and measurement. The research objectives undertaken in this dissertation are as follows. (1) Improve theoretical modeling and experimental identification of viscoelasticity in soft biological tissues. (2) Develop a poroviscoelastic model for lung tissue vibroacoustics. (3) Improve lung airway acoustics modeling and its

  13. Modeling the dynamics of recruitment and derecruitment in mice with acute lung injury.

    PubMed

    Massa, Christopher B; Allen, Gilman B; Bates, Jason H T

    2008-12-01

    Lung recruitment and derecruitment contribute significantly to variations in the elastance of the respiratory system during mechanical ventilation. However, the decreases in elastance that occur with deep inflation are transient, especially in acute lung injury. Bates and Irvin (8) proposed a model of the lung that recreates time-varying changes in elastance as a result of progressive recruitment and derecruitment of lung units. The model is characterized by distributions of critical opening and closing pressures throughout the lung and by distributions of speeds with which the processes of opening and closing take place once the critical pressures have been achieved. In the present study, we adapted this model to represent a mechanically ventilated mouse. We fit the model to data collected in a previous study from control mice and mice in various stages of acid-induced acute lung injury (3). Excellent fits to the data were obtained when the normally distributed critical opening pressures were about 5 cmH(2)O above the closing pressures and when the hyperbolically distributed opening velocities were about an order of magnitude greater than the closing velocities. We also found that, compared with controls, the injured mice had markedly increased opening and closing pressures but no change in the velocities, suggesting that the key biophysical change wrought by acid injury is dysfunction of surface tension at the air-liquid interface. Our computational model of lung recruitment and derecruitment dynamics is thus capable of accurately mimicking data from mice with acute lung injury and may provide insight into the altered biophysics of the injured lung. PMID:18948446

  14. Ex vivo Raman spectroscopic study of breast metastatic lesions in lungs in animal models.

    PubMed

    Bhattacharjee, Tanmoy; Tawde, Sneha; Hudlikar, Rasika; Mahimkar, Manoj; Maru, Girish; Ingle, Arvind; Murali Krishna, C

    2015-08-01

    The lung is one of the most common sites of metastases, with approximately 50% of patients with extrathoracic cancer exhibiting pulmonary metastases. Correct identification of the metastatic status of a lung lesion is vital to therapeutic planning and better prognosis. However, currently available diagnostic techniques, such as conventional radiography and low dose computed tomography (LDCT), may fail to identify metastatic lesions. Alternative techniques such as Raman spectroscopy (RS) are hence being extensively explored for correct diagnosis of metastasis. The current ex vivo study aims to evaluate the ability of a fiber optic-based Raman system to distinguish breast cancer metastasis in lung from primary breast and lung tumor in animal models. In this study, spectra were acquired from normal breast, primary breast tumor, normal lung, primary lung tumor, and breast cancer metastasis in lung tissues and analyzed using principal component analysis and principal component-linear discriminant analysis. Breast cancer metastasis in lung could be classified with 71% classification efficiency. Approximately 6% breast metastasis spectra were misclassified with breast tumor, probably due to the presence of breast cancer cells in metastasized lungs. Test prediction results show 64% correct prediction of breast metastasis, while 13% breast metastasis spectra were wrongly predicted as breast tumor, suggesting the possible influence of breast cancer cells. Thus, findings of this study, the first of such explorations, demonstrate the potential of RS in classifying breast metastasis in lungs from primary lung and primary breast tumor. Prospective evaluation on a larger cohort with better multivariate analysis, combined with LDCT and recently developed real-time in vivo probes, RS can play a significant role in nonsurgical screening of lesions, which can lead to individualized therapeutic regimes and improved prognoses. PMID:26295177

  15. Hypercapnia modulates cAMP signalling and cystic fibrosis transmembrane conductance regulator-dependent anion and fluid secretion in airway epithelia.

    PubMed

    Turner, Mark J; Saint-Criq, Vinciane; Patel, Waseema; Ibrahim, Salam H; Verdon, Bernard; Ward, Christopher; Garnett, James P; Tarran, Robert; Cann, Martin J; Gray, Michael A

    2016-03-15

    Hypercapnia is clinically defined as an arterial blood partial pressure of CO2 of above 40 mmHg and is a feature of chronic lung disease. In previous studies we have demonstrated that hypercapnia modulates agonist-stimulated cAMP levels through effects on transmembrane adenylyl cyclase activity. In the airways, cAMP is known to regulate cystic fibrosis transmembrane conductance regulator (CFTR)-mediated anion and fluid secretion, which contributes to airway surface liquid homeostasis. The aim of the current work was to investigate if hypercapnia could modulate cAMP-regulated ion and fluid transport in human airway epithelial cells. We found that acute exposure to hypercapnia significantly reduced forskolin-stimulated elevations in intracellular cAMP as well as both adenosine- and forskolin-stimulated increases in CFTR-dependent transepithelial short-circuit current, in polarised cultures of Calu-3 human airway cells. This CO2 -induced reduction in anion secretion was not due to a decrease in HCO3 (-) transport given that neither a change in CFTR-dependent HCO3 (-) efflux nor Na(+) /HCO3 (-) cotransporter-dependent HCO3 (-) influx were CO2 -sensitive. Hypercapnia also reduced the volume of forskolin-stimulated fluid secretion over 24 h, yet had no effect on the HCO3 (-) content of the secreted fluid. Our data reveal that hypercapnia reduces CFTR-dependent, electrogenic Cl(-) and fluid secretion, but not CFTR-dependent HCO3 (-) secretion, which highlights a differential sensitivity of Cl(-) and HCO3 (-) transporters to raised CO2 in Calu-3 cells. Hypercapnia also reduced forskolin-stimulated CFTR-dependent anion secretion in primary human airway epithelia. Based on current models of airways biology, a reduction in fluid secretion, associated with hypercapnia, would be predicted to have important consequences for airways hydration and the innate defence mechanisms of the lungs. PMID:26574187

  16. Dynamics of Bacterial Community Composition in the Malaria Mosquito's Epithelia

    PubMed Central

    Tchioffo, Majoline T.; Boissière, Anne; Abate, Luc; Nsango, Sandrine E.; Bayibéki, Albert N.; Awono-Ambéné, Parfait H.; Christen, Richard; Gimonneau, Geoffrey; Morlais, Isabelle

    2016-01-01

    The Anopheles midgut hosts diverse bacterial communities and represents a complex ecosystem. Several evidences indicate that mosquito midgut microbiota interferes with malaria parasite transmission. However, the bacterial composition of salivary glands and ovaries, two other biologically important tissues, has not been described so far. In this study, we investigated the dynamics of the bacterial communities in the mosquito tissues from emerging mosquitoes until 8 days after a blood meal containing Plasmodium falciparum gametocytes and described the temporal colonization of the mosquito epithelia. Bacterial communities were identified in the midgut, ovaries, and salivary glands of individual mosquitoes using pyrosequencing of the 16S rRNA gene. We found that the mosquito epithelia share a core microbiota, but some bacteria taxa were more associated with one or another tissue at a particular time point. The bacterial composition in the tissues of emerging mosquitoes varied according to the breeding site, indicating that some bacteria are acquired from the environment. Our results revealed temporal variations in the bacterial community structure, possibly as a result of the mosquito physiological changes. The abundance of Serratia significantly correlated with P. falciparum infection both in the midgut and salivary glands of malaria challenged mosquitoes, which suggests that interactions occur between microbes and parasites. These bacteria may represent promising targets for vector control strategies. Overall, this study points out the importance of characterizing bacterial communities in malaria mosquito vectors. PMID:26779155

  17. 17β-Estradiol inhibits Ca2+-dependent homeostasis of airway surface liquid volume in human cystic fibrosis airway epithelia

    PubMed Central

    Coakley, Ray D.; Sun, Hengrui; Clunes, Lucy A.; Rasmussen, Julia E.; Stackhouse, James R.; Okada, Seiko F.; Fricks, Ingrid; Young, Steven L.; Tarran, Robert

    2008-01-01

    Normal airways homeostatically regulate the volume of airway surface liquid (ASL) through both cAMP- and Ca2+-dependent regulation of ion and water transport. In cystic fibrosis (CF), a genetic defect causes a lack of cAMP-regulated CFTR activity, leading to diminished Cl– and water secretion from airway epithelial cells and subsequent mucus plugging, which serves as the focus for infections. Females with CF exhibit reduced survival compared with males with CF, although the mechanisms underlying this sex-related disadvantage are unknown. Despite the lack of CFTR, CF airways retain a limited capability to regulate ASL volume, as breathing-induced ATP release activates salvage purinergic pathways that raise intracellular Ca2+ concentration to stimulate an alternate pathway to Cl– secretion. We hypothesized that estrogen might affect this pathway by reducing the ability of airway epithelia to respond appropriately to nucleotides. We found that uridine triphosphate–mediated (UTP-mediated) Cl– secretion was reduced during the periovulatory estrogen maxima in both women with CF and normal, healthy women. Estrogen also inhibited Ca2+ signaling and ASL volume homeostasis in non-CF and CF airway epithelia by attenuating Ca2+ influx. This inhibition of Ca2+ signaling was prevented and even potentiated by estrogen antagonists such as tamoxifen, suggesting that antiestrogens may be beneficial in the treatment of CF lung disease because they increase Cl– secretion in the airways. PMID:19033671

  18. Cold stress aggravates inflammatory responses in an LPS-induced mouse model of acute lung injury.

    PubMed

    Joo, Su-Yeon; Park, Mi-Ju; Kim, Kyun-Ha; Choi, Hee-Jung; Chung, Tae-Wook; Kim, Yong Jin; Kim, Joung Hee; Kim, Keuk-Jun; Joo, Myungsoo; Ha, Ki-Tae

    2016-08-01

    Although the relationship between environmental cold temperature and susceptibility to respiratory infection is generally accepted, the effect of ambient cold temperature on host reactivity in lung inflammation has not been fully studied. To examine the function of ambient cold temperature on lung inflammation, mice were exposed to 4 °C for 8 h each day for 14 days. In the lungs of mice exposed to cold stress, inflammatory cells in bronchoalveolar lavage (BAL) fluid and lung tissues were slightly increased by about twofold. However, the structures of pulmonary epithelial cells were kept within normal limits. Next, we examined the effect of cold stress on the inflammatory responses in a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. The infiltration of neutrophils and inflammation of lung tissue determined by histology were significantly increased by exposure to ambient cold temperature. In addition, the production of pro-inflammatory cytokines including interleukin (IL)-12, IL-17, and monokine induced by gamma interferon (MIG) was elevated by exposure to cold stress. Therefore, we suggest that cold stress is a factor that exacerbates lung inflammation including ALI. To our knowledge, this is the first report on the relationship between cold stress and severity of lung inflammation. PMID:26617279

  19. Conditions for NIR fluorescence-guided tumor resectioning in preclinical lung cancer model (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kim, Minji; Quan, Yuhua; Choi, Byeong Hyun; Choi, Yeonho; Kim, Hyun Koo; Kim, Beop-Min

    2016-03-01

    Pulmonary nodule could be identified by intraoperative fluorescence imaging system from systemic injection of indocyanine green (ICG) which achieves enhanced permeability and retention (EPR) effects. This study was performed to evaluate optimal injection time of ICG for detecting cancer during surgery in rabbit lung cancer model. VX2 carcinoma cell was injected in rabbit lung under fluoroscopic computed tomography-guidance. Solitary lung cancer was confirmed on positron emitting tomography with CT (PET/CT) 2 weeks after inoculation. ICG was administered intravenously and fluorescent intensity of lung tumor was measured using the custom-built intraoperative color and fluorescence merged imaging system (ICFIS) for 15 hours. Solitary lung cancer was resected through thoracoscopic version of ICFIS. ICG was observed in all animals. Because Lung has fast blood pulmonary circulation, Fluorescent signal showed maximum intensity earlier than previous studies in other organs. Fluorescent intensity showed maximum intensity within 6-9 hours in rabbit lung cancer. Overall, Fluorescent intensity decreased with increasing time, however, all tumors were detectable using fluorescent images until 12 hours. In conclusion, while there had been studies in other organs showed that optimal injection time was at least 24 hours before operation, this study showed shorter optimal injection time at lung cancer. Since fluorescent signal showed the maximum intensity within 6-9 hours, cancer resection could be performed during this time. This data informed us that optimal injection time of ICG should be evaluated in each different solid organ tumor for fluorescent image guided surgery.

  20. Cold stress aggravates inflammatory responses in an LPS-induced mouse model of acute lung injury

    NASA Astrophysics Data System (ADS)

    Joo, Su-Yeon; Park, Mi-Ju; Kim, Kyun-Ha; Choi, Hee-Jung; Chung, Tae-Wook; Kim, Yong Jin; Kim, Joung Hee; Kim, Keuk-Jun; Joo, Myungsoo; Ha, Ki-Tae

    2016-08-01

    Although the relationship between environmental cold temperature and susceptibility to respiratory infection is generally accepted, the effect of ambient cold temperature on host reactivity in lung inflammation has not been fully studied. To examine the function of ambient cold temperature on lung inflammation, mice were exposed to 4 °C for 8 h each day for 14 days. In the lungs of mice exposed to cold stress, inflammatory cells in bronchoalveolar lavage (BAL) fluid and lung tissues were slightly increased by about twofold. However, the structures of pulmonary epithelial cells were kept within normal limits. Next, we examined the effect of cold stress on the inflammatory responses in a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. The infiltration of neutrophils and inflammation of lung tissue determined by histology were significantly increased by exposure to ambient cold temperature. In addition, the production of pro-inflammatory cytokines including interleukin (IL)-12, IL-17, and monokine induced by gamma interferon (MIG) was elevated by exposure to cold stress. Therefore, we suggest that cold stress is a factor that exacerbates lung inflammation including ALI. To our knowledge, this is the first report on the relationship between cold stress and severity of lung inflammation.

  1. Cold stress aggravates inflammatory responses in an LPS-induced mouse model of acute lung injury

    NASA Astrophysics Data System (ADS)

    Joo, Su-Yeon; Park, Mi-Ju; Kim, Kyun-Ha; Choi, Hee-Jung; Chung, Tae-Wook; Kim, Yong Jin; Kim, Joung Hee; Kim, Keuk-Jun; Joo, Myungsoo; Ha, Ki-Tae

    2015-11-01

    Although the relationship between environmental cold temperature and susceptibility to respiratory infection is generally accepted, the effect of ambient cold temperature on host reactivity in lung inflammation has not been fully studied. To examine the function of ambient cold temperature on lung inflammation, mice were exposed to 4 °C for 8 h each day for 14 days. In the lungs of mice exposed to cold stress, inflammatory cells in bronchoalveolar lavage (BAL) fluid and lung tissues were slightly increased by about twofold. However, the structures of pulmonary epithelial cells were kept within normal limits. Next, we examined the effect of cold stress on the inflammatory responses in a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. The infiltration of neutrophils and inflammation of lung tissue determined by histology were significantly increased by exposure to ambient cold temperature. In addition, the production of pro-inflammatory cytokines including interleukin (IL)-12, IL-17, and monokine induced by gamma interferon (MIG) was elevated by exposure to cold stress. Therefore, we suggest that cold stress is a factor that exacerbates lung inflammation including ALI. To our knowledge, this is the first report on the relationship between cold stress and severity of lung inflammation.

  2. Lung Segmentation in 4D CT Volumes Based on Robust Active Shape Model Matching

    PubMed Central

    Gill, Gurman; Beichel, Reinhard R.

    2015-01-01

    Dynamic and longitudinal lung CT imaging produce 4D lung image data sets, enabling applications like radiation treatment planning or assessment of response to treatment of lung diseases. In this paper, we present a 4D lung segmentation method that mutually utilizes all individual CT volumes to derive segmentations for each CT data set. Our approach is based on a 3D robust active shape model and extends it to fully utilize 4D lung image data sets. This yields an initial segmentation for the 4D volume, which is then refined by using a 4D optimal surface finding algorithm. The approach was evaluated on a diverse set of 152 CT scans of normal and diseased lungs, consisting of total lung capacity and functional residual capacity scan pairs. In addition, a comparison to a 3D segmentation method and a registration based 4D lung segmentation approach was performed. The proposed 4D method obtained an average Dice coefficient of 0.9773 ± 0.0254, which was statistically significantly better (p value ≪0.001) than the 3D method (0.9659 ± 0.0517). Compared to the registration based 4D method, our method obtained better or similar performance, but was 58.6% faster. Also, the method can be easily expanded to process 4D CT data sets consisting of several volumes. PMID:26557844

  3. Current Status of Gene Therapy for Inherited Lung Diseases

    PubMed Central

    Driskell, Ryan R.; Engelhardt, John F.

    2007-01-01

    Gene therapy as a treatment modality for pulmonary disorders has attracted significant interest over the past decade. Since the initiation of the first clinical trials for cystic fibrosis lung disease using recombinant adenovirus in the early 1990s, the field has encountered numerous obstacles including vector inflammation, inefficient delivery, and vector production. Despite these obstacles, enthusiasm for lung gene therapy remains high. In part, this enthusiasm is fueled through the diligence of numerous researchers whose studies continue to reveal great potential of new gene transfer vectors that demonstrate increased tropism for airway epithelia. Several newly identified serotypes of adeno-associated virus have demonstrated substantial promise in animal models and will likely surface soon in clinical trials. Furthermore, an increased understanding of vector biology has also led to the development of new technologies to enhance the efficiency and selectivity of gene delivery to the lung. Although the promise of gene therapy to the lung has yet to be realized, the recent concentrated efforts in the field that focus on the basic virology of vector development will undoubtedly reap great rewards over the next decade in treating lung diseases. PMID:12524461

  4. Determination of the pharmacokinetics of glycopyrronium in the lung using a population pharmacokinetic modelling approach

    PubMed Central

    Bartels, Christian; Looby, Michael; Sechaud, Romain; Kaiser, Guenther

    2013-01-01

    Aims Glycopyrronium bromide (NVA237) is a once-daily long-acting muscarinic antagonist recently approved for the treatment of chronic obstructive pulmonary disease. In this study, we used population pharmacokinetic (PK) modelling to provide insights into the impact of the lung PK of glycopyrronium on its systemic PK profile and, in turn, to understand the impact of lung bioavailability and residence time on the choice of dosage regimen. Methods We developed and validated a population PK model to characterize the lung absorption of glycopyrronium using plasma PK data derived from studies in which this drug was administered by different routes to healthy volunteers. The model was also used to carry out simulations of once-daily and twice-daily regimens and to characterize amounts of glycopyrronium in systemic compartments and lungs. Results The model-derived PK parameters were comparable to those obtained with noncompartmental analysis, confirming the usefulness of our model. The model suggested that the lung absorption of glycopyrronium was dominated by slow-phase absorption with a half-life of about 3.5 days, which accounted for 79% of drug absorbed through the lungs into the bloodstream, from where glycopyrronium was quickly eliminated. Simulations of once-daily and twice-daily administration generated similar PK profiles in the lung compartments. Conclusions The slow absorption from the lungs, together with the rapid elimination from the systemic circulation, could explain how once-daily glycopyrronium provides sustained bronchodilatation with a low incidence of adverse effects in patients with chronic obstructive pulmonary disease. Its extended intrapulmonary residence time also provides pharmacokinetic evidence that glycopyrronium has the profile of a once-daily drug. PMID:23506208

  5. Towards an Ecology of the Lung: New Conceptual Models of Pulmonary Microbiology and Pneumonia Pathogenesis

    PubMed Central

    Dickson, Robert P.; Erb-Downward, John R.; Huffnagle, Gary B.

    2014-01-01

    Summary Pneumonia is a major cause of morbidity and mortality for which no new methods of treatment have entered clinical practice since the discovery of antibiotics. Innovations in the techniques of culture-independent microbial identification have shown that the lungs, previously deemed sterile in the absence of infection, contain diverse and dynamic communities of microbes. In this Personal View, we argue that these observations have shown the inadequacy of traditional conceptual models of lung microbiology and the pathogenesis of pneumonia, hampering progress in research and practice. We propose three new conceptual models to replace the traditional models of lung microbiology: an adapted island model of lung biogeography, the effect of environmental gradients on lung microbiota, and pneumonia as an emergent phenomenon propelled by unexplored positive feedback loops. We argue that the ecosystem of lung microbiota has all of the features of a complex adaptive system: diverse entities interacting with each other within a common space, showing interdependent actions and possessing the capacity to adapt to changes in conditions. Complex adaptive systems are fundamentally different in behaviour from the simple, linear systems typified by the traditional model of pneumonia pathogenesis, and need distinct analytical approaches. PMID:24621685

  6. Airway geometry models of children's lungs for use in dosimetry modeling.

    PubMed

    Ménache, M G; Hofmann, W; Ashgarian, B; Miller, F J

    2008-01-01

    Single-path whole-lung and lobar models of the lungs of 11 children between 3 mo and 21 yr of age were developed based on a combination of cast data and published information on distal airway dimensions. The cast data used to generate these models were taken from one of the largest databases of actual measurements in children. The methods used to develop the children's models were based on techniques that have been used to develop adult single-path airway geometry models. Model dimensions for the conducting airways, as well as the estimated dead space, for all children fell within the range of the limited published information. Thus, the method for estimating airway dimensions in adults may be successfully applied to develop estimates of airway dimensions in children. The predicted total lung capacity (TLC) for the older children (aged 8 to 21 yr) fell within or near the range arising from published scaling equations. The assumptions used to generate the gas exchange region for children 8 yr and older produced results that were reasonably consistent with available physiological data. However, these assumptions do not result in a physiologically consistent gas exchange region for children 3 yr of age and younger; also, to maintain physiologically reasonable relationships between dead space and alveolar volume, the models for children 3 yr of age and younger resulted in predicted TLCs well below those predicted using published scaling equations. These discrepancies may be reflective of dysanaptic growth, in which the alveolar region is growing more rapidly than the airways. The results for children 3 yr of age and under suggest the need for a greater understanding of lung development during this critical period. This is particularly important considering the increasing evidence that exposure to pollutants and other toxicants and allergens during the first 2 yr of life may have long-term consequences on respiratory disease outcomes. Our results suggest that the

  7. Stigma among patients with lung cancer: A patient-reported measurement model

    PubMed Central

    Hamann, Heidi A.; Ostroff, Jamie S.; Marks, Emily G.; Gerber, David E.; Schiller, Joan H.; Craddock Lee, Simon J.

    2014-01-01

    Objective Although stigma may have negative psychosocial and behavioral outcomes for patients with lung cancer, its measurement has been limited. A conceptual model of lung cancer stigma and a patient-reported outcome (PRO) measure is needed to mitigate these sequelae. This study identified key stigma-related themes to provide a blueprint for item development through thematic analysis of semi-structured interviews and focus groups with lung cancer patients. Methods Participants were recruited from two outpatient oncology clinics and included: a) 42 lung cancer patients who participated in individual interviews and, b) 5 focus groups (inclusive of 23 new lung cancer patients). Never smokers, long-term quitters, recent quitters, and current smokers participated. Individual interviews facilitated theme development and a conceptual model of lung cancer stigma, whereas subsequent focus groups provided feedback on the conceptual model. Qualitative data analyses included iterative coding and validation with existing theory. Results Two main thematic elements emerged from interviews with lung cancer patients: perceived (felt) stigma and internalized (self) stigma. Discussions of perceived stigma were pervasive, while internalized stigma was more commonly endorsed among current and recently quit smokers. Participants also discussed maladaptive (e.g., decreased disclosure) and adaptive (e.g., increased advocacy) stigma-related consequences. Conclusions Results indicate widespread acknowledgment of perceived stigma among lung cancer patients, but varying degrees of internalized stigma and associated consequences. Next steps for PRO measure development are item consolidation, item development, expert input, and cognitive interviews before field testing and psychometric analysis. Future work should address stigma-related consequences and interventions for reducing lung cancer stigma. PMID:24123664

  8. Theoretical modeling of the interaction between alveoli during inflation and deflation in normal and diseased lungs.

    PubMed

    Schirrmann, Kerstin; Mertens, Michael; Kertzscher, Ulrich; Kuebler, Wolfgang M; Affeld, Klaus

    2010-04-19

    Alveolar recruitment is a central strategy in the ventilation of patients with acute lung injury and other lung diseases associated with alveolar collapse and atelectasis. However, biomechanical insights into the opening and collapse of individual alveoli are still limited. A better understanding of alveolar recruitment and the interaction between alveoli in intact and injured lungs is of crucial relevance for the evaluation of the potential efficacy of ventilation strategies. We simulated human alveolar biomechanics in normal and injured lungs. We used a basic simulation model for the biomechanical behavior of virtual single alveoli to compute parameterized pressure-volume curves. Based on these curves, we analyzed the interaction and stability in a system composed of two alveoli. We introduced different values for surface tension and tissue properties to simulate different forms of lung injury. The data obtained predict that alveoli with identical properties can coexist with both different volumes and with equal volumes depending on the pressure. Alveoli in injured lungs with increased surface tension will collapse at normal breathing pressures. However, recruitment maneuvers and positive endexpiratory pressure can stabilize those alveoli, but coexisting unaffected alveoli might be overdistended. In injured alveoli with reduced compliance collapse is less likely, alveoli are expected to remain open, but with a smaller volume. Expanding them to normal size would overdistend coexisting unaffected alveoli. The present simulation model yields novel insights into the interaction between alveoli and may thus increase our understanding of the prospects of recruitment maneuvers in different forms of lung injury. PMID:20031137

  9. An integrated physiology model to study regional lung damage effects and the physiologic response

    PubMed Central

    2014-01-01

    Background This work expands upon a previously developed exercise dynamic physiology model (DPM) with the addition of an anatomic pulmonary system in order to quantify the impact of lung damage on oxygen transport and physical performance decrement. Methods A pulmonary model is derived with an anatomic structure based on morphometric measurements, accounting for heterogeneous ventilation and perfusion observed experimentally. The model is incorporated into an existing exercise physiology model; the combined system is validated using human exercise data. Pulmonary damage from blast, blunt trauma, and chemical injury is quantified in the model based on lung fluid infiltration (edema) which reduces oxygen delivery to the blood. The pulmonary damage component is derived and calibrated based on published animal experiments; scaling laws are used to predict the human response to lung injury in terms of physical performance decrement. Results The augmented dynamic physiology model (DPM) accurately predicted the human response to hypoxia, altitude, and exercise observed experimentally. The pulmonary damage parameters (shunt and diffusing capacity reduction) were fit to experimental animal data obtained in blast, blunt trauma, and chemical damage studies which link lung damage to lung weight change; the model is able to predict the reduced oxygen delivery in damage conditions. The model accurately estimates physical performance reduction with pulmonary damage. Conclusions We have developed a physiologically-based mathematical model to predict performance decrement endpoints in the presence of thoracic damage; simulations can be extended to estimate human performance and escape in extreme situations. PMID:25044032

  10. Generation of ESC-derived Mouse Airway Epithelial Cells Using Decellularized Lung Scaffolds.

    PubMed

    Shojaie, Sharareh; Lee, Joyce; Wang, Jinxia; Ackerley, Cameron; Post, Martin

    2016-01-01

    Lung lineage differentiation requires integration of complex environmental cues that include growth factor signaling, cell-cell interactions and cell-matrix interactions. Due to this complexity, recapitulation of lung development in vitro to promote differentiation of stem cells to lung epithelial cells has been challenging. In this protocol, decellularized lung scaffolds are used to mimic the 3-dimensional environment of the lung and generate stem cell-derived airway epithelial cells. Mouse embryonic stem cell are first differentiated to the endoderm lineage using an embryoid body (EB) culture method with activin A. Endoderm cells are then seeded onto decellularized scaffolds and cultured at air-liquid interface for up to 21 days. This technique promotes differentiation of seeded cells to functional airway epithelial cells (ciliated cells, club cells, and basal cells) without additional growth factor supplementation. This culture setup is defined, serum-free, inexpensive, and reproducible. Although there is limited contamination from non-lung endoderm lineages in culture, this protocol only generates airway epithelial populations and does not give rise to alveolar epithelial cells. Airway epithelia generated with this protocol can be used to study cell-matrix interactions during lung organogenesis and for disease modeling or drug-discovery platforms of airway-related pathologies such as cystic fibrosis. PMID:27214388

  11. Impaired Cell Volume Regulation in Intestinal Crypt Epithelia of Cystic Fibrosis Mice

    NASA Astrophysics Data System (ADS)

    Valverde, M. A.; O'Brien, J. A.; Sepulveda, F. V.; Ratcliff, R. A.; Evans, M. J.; Colledge, W. H.

    1995-09-01

    Cystic fibrosis is a disease characterized by abnormalities in the epithelia of the lungs, intestine, salivary and sweat glands, liver, and reproductive systems, often as a result of inadequate hydration of their secretions. The primary defect in cystic fibrosis is the altered activity of a cAMP-activated Cl^- channel, the cystic fibrosis transmembrane conductance regulator (CFTR) channel. However, it is not clear how a defect in the CFTR Cl^- channel function leads to the observed pathological changes. Although much is known about the structural properties and regulation of the CFTR, little is known of its relationship to cellular functions other than the cAMP-dependent Cl^- secretion. Here we report that cell volume regulation after hypotonic challenge is also defective in intestinal crypt epithelial cells isolated from CFTR -/- mutant mice. Moreover, the impairment of the regulatory volume decrease in CFTR -/- crypts appears to be related to the inability of a K^+ conductance to provide a pathway for the exit of this cation during the volume adjustments. This provides evidence that the lack of CFTR protein may have additional consequences for the cellular function other than the abnormal cAMP-mediated Cl^- secretion.

  12. Meta-analysis of the turnover of intestinal epithelia in preclinical animal species and humans.

    PubMed

    Darwich, Adam S; Aslam, Umair; Ashcroft, Darren M; Rostami-Hodjegan, Amin

    2014-12-01

    Due to the rapid turnover of the small intestinal epithelia, the rate at which enterocyte renewal occurs plays an important role in determining the level of drug-metabolizing enzymes in the gut wall. Current physiologically based pharmacokinetic (PBPK) models consider enzyme and enterocyte recovery as a lumped first-order rate. An assessment of enterocyte turnover would enable enzyme and enterocyte renewal to be modeled more mechanistically. A literature review together with statistical analysis was employed to establish enterocyte turnover in human and preclinical species. A total of 85 studies was identified reporting enterocyte turnover in 1602 subjects in six species. In mice, the geometric weighted combined mean (WX) enterocyte turnover was 2.81 ± 1.14 days (n = 169). In rats, the weighted arithmetic mean enterocyte turnover was determined to be 2.37 days (n = 501). Humans exhibited a geometric WX enterocyte turnover of 3.48 ± 1.55 days for the gastrointestinal epithelia (n = 265), displaying comparable turnover to that of cytochrome P450 enzymes in vitro (0.96-4.33 days). Statistical analysis indicated humans to display longer enterocyte turnover as compared with preclinical species. Extracted data were too sparse to support regional differences in small intestinal enterocyte turnover in humans despite being indicated in mice. The utilization of enterocyte turnover data, together with in vitro enzyme turnover in PBPK modeling, may improve the predictions of metabolic drug-drug interactions dependent on enzyme turnover (e.g., mechanism-based inhibition and enzyme induction) as well as absorption of nanoparticle delivery systems and intestinal metabolism in special populations exhibiting altered enterocyte turnover. PMID:25233858

  13. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens.

    PubMed

    López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M; Gibert, Isidre

    2015-01-01

    Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host-pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host-pathogen interactions. PMID:25699030

  14. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens

    PubMed Central

    López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M.; Gibert, Isidre

    2015-01-01

    Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host–pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host–pathogen interactions. PMID:25699030

  15. Evaluation and application of 3D lung warping and registration model using HRCT images

    NASA Astrophysics Data System (ADS)

    Fan, Li; Chen, Chang W.; Reinhardt, Joseph M.; Hoffman, Eric A.

    2001-05-01

    Image-based study of structure-function relationships is a challenging problem in that the structure or region of interest may vary in position and shape on images captured over time. Such variation may be caused by the change in body posture or the motion of breathing and heart beating. Therefore, the structure or region of interest should be registered before any further regional study can be carried out. In this paper, we propose a novel approach to study the structure-function relationship of ventilation using a previously developed 3D lung warping and registration model. First, we evaluate the effectiveness of the lung warping and registration model using a set of criteria, including apparent lung motion patterns and ground truths. Then, we study the ventilation by integrating the warping model with air content calibration. The warping model is applied to three CT lung data sets, obtained under volume control of FRC, 40% and 75% vital capacity (VC). Dense displacement fields are obtained to represent deformation between different lung volume steps. For any specific region of interest, we first register it between images over time using the dense displacement, and then estimate the corresponding regional inspired air content. Assessments include change of regional volume during inspiration, change of regional air content, and the distribution of regional ventilation. This is the first time that 3D warping of lung images is applied to assess clinically significant pulmonary functions.

  16. Mineral-fluid interaction in the lungs: insights from reaction-path modeling.

    PubMed

    Wood, Scott A; Taunton, Anne E; Normand, Charles; Gunter, Mickey E

    2006-11-01

    Thermodynamic modeling, in conjunction with available kinetic information, has been employed to investigate the fate of chrysotile and tremolite in the human lung. In particular, we focus on mineral-fluid reactions using techniques borrowed from geochemistry, including calculation of saturation indices, activity-ratio phase diagrams, and reaction-path modeling. Saturation index calculations show that fresh lung fluid is undersaturated with respect to both tremolite and chrysotile and these minerals should dissolve, in accordance with conclusions from previous work described in the literature. Modeling of reaction paths in both closed and open systems confirms previous suggestions that chrysotile dissolves faster than tremolite in lung fluid, which offers an explanation for the apparent increase in tremolite/chrysotile ratios in lungs of miners and millers over time. However, examination of activity-ratio phase diagrams and reaction-path model calculations raises the possibility not only that minerals dissolve congruently in lung fluid, but that secondary minerals such as talc or various Ca-Mg carbonates might potentially form in lung fluid as asbestiform minerals dissolve. PMID:16920671

  17. Toward in vivo lung's tissue incompressibility characterization for tumor motion modeling in radiation therapy

    SciTech Connect

    Shirzadi, Zahra; Sadeghi-Naini, Ali; Samani, Abbas

    2013-05-15

    Purpose: A novel technique is proposed to characterize lung tissue incompressibility variation during respiration. Estimating lung tissue incompressibility parameter variations resulting from air content variation throughout respiration is critical for computer assisted tumor motion tracking. Continuous tumor motion is a major challenge in lung cancer radiotherapy, especially with external beam radiotherapy. If not accounted for, this motion may lead to areas of radiation overdosage for normal tissue. Given the unavailability of imaging modality that can be used effectively for real-time lung tumor tracking, computer assisted approach based on tissue deformation estimation can be a good alternative. This approach involves lung biomechanical model where its fidelity depends on input tissue properties. This investigation shows that considering variable tissue incompressibility parameter is very important for predicting tumor motion accurately, hence improving the lung radiotherapy outcome. Methods: First, an in silico lung phantom study was conducted to demonstrate the importance of employing variable Poisson's ratio for tumor motion predication. After it was established that modeling this variability is critical for accurate tumor motion prediction, an optimization based technique was developed to estimate lung tissue Poisson's ratio as a function of respiration cycle time. In this technique, the Poisson's ratio and lung pressure value were varied systematically until optimal values were obtained, leading to maximum similarity between acquired and simulated 4D CT lung images. This technique was applied in an ex vivo porcine lung study where simulated images were constructed using the end exhale CT image and deformation fields obtained from the lung's FE modeling of each respiration time increment. To model the tissue, linear elastic and Marlow hyperelastic material models in conjunction with variable Poisson's ratio were used. Results: The phantom study showed that

  18. Early recognition of lung cancer by integrin targeted imaging in K-ras mouse model.

    PubMed

    Ermolayev, Vladimir; Mohajerani, Pouyan; Ale, Angelique; Sarantopoulos, Athanasios; Aichler, Michaela; Kayser, Gian; Walch, Axel; Ntziachristos, Vasilis

    2015-09-01

    Non-small cell lung cancer is characterized by slow progression and high heterogeneity of tumors. Integrins play an important role in lung cancer development and metastasis and were suggested as a tumor marker; however their role in anticancer therapy remains controversial. In this work, we demonstrate the potential of integrin-targeted imaging to recognize early lesions in transgenic mouse model of lung cancer based on spontaneous introduction of mutated human gene bearing K-ras mutation. We conducted ex vivo and fluorescence molecular tomography-X-ray computed tomography (FMT-XCT) in vivo imaging and analysis for specific targeting of early lung lesions and tumors in rodent preclinical model for lung cancer. The lesions and tumors were characterized by histology, immunofluorescence and immunohistochemistry using a panel of cancer markers. Ex vivo, the integrin-targeted fluorescent signal significantly differed between wild type lung tissue and K-ras pulmonary lesions (PL) at all ages studied. The panel of immunofluorescence experiments demonstrated that PL, which only partially show cancer cell features were detected by αvβ3-integrin targeted imaging. Human patient material analysis confirmed the specificity of target localization in different lung cancer types. Most importantly, small tumors in the lungs of 4-week-old animals could be noninvasively detected in vivo on the fluorescence channel of FMT-XCT. Our findings demonstrated αvβ3-integrin targeted fluorescent imaging to specifically detect premalignant pleural lesions in K-ras mice. Integrin targeted imaging may find application areas in preclinical research and clinical practice, such as early lung cancer diagnostics, intraoperative assistance or therapy monitoring. PMID:25450481

  19. Chronic inflammation imposes aberrant cell fate in regenerating epithelia through mechanotransduction.

    PubMed

    Nowell, Craig S; Odermatt, Pascal D; Azzolin, Luca; Hohnel, Sylke; Wagner, Erwin F; Fantner, Georg E; Lutolf, Matthias P; Barrandon, Yann; Piccolo, Stefano; Radtke, Freddy

    2016-02-01

    Chronic inflammation is associated with a variety of pathological conditions in epithelial tissues, including cancer, metaplasia and aberrant wound healing. In relation to this, a significant body of evidence suggests that aberration of epithelial stem and progenitor cell function is a contributing factor in inflammation-related disease, although the underlying cellular and molecular mechanisms remain to be fully elucidated. In this study, we have delineated the effect of chronic inflammation on epithelial stem/progenitor cells using the corneal epithelium as a model tissue. Using a combination of mouse genetics, pharmacological approaches and in vitro assays, we demonstrate that chronic inflammation elicits aberrant mechanotransduction in the regenerating corneal epithelium. As a consequence, a YAP-TAZ/β-catenin cascade is triggered, resulting in the induction of epidermal differentiation on the ocular surface. Collectively, the results of this study demonstrate that chronic inflammation and mechanotransduction are linked and act to elicit pathological responses in regenerating epithelia. PMID:26689676

  20. A Highly Efficient Gene Expression Programming (GEP) Model for Auxiliary Diagnosis of Small Cell Lung Cancer

    PubMed Central

    Si, Hongzong; Liu, Shihai; Li, Xianchao; Gao, Caihong; Cui, Lianhua; Li, Chuan; Yang, Xue; Yao, Xiaojun

    2015-01-01

    Background Lung cancer is an important and common cancer that constitutes a major public health problem, but early detection of small cell lung cancer can significantly improve the survival rate of cancer patients. A number of serum biomarkers have been used in the diagnosis of lung cancers; however, they exhibit low sensitivity and specificity. Methods We used biochemical methods to measure blood levels of lactate dehydrogenase (LDH), C-reactive protein (CRP), Na+, Cl-, carcino-embryonic antigen (CEA), and neuron specific enolase (NSE) in 145 small cell lung cancer (SCLC) patients and 155 non-small cell lung cancer and 155 normal controls. A gene expression programming (GEP) model and Receiver Operating Characteristic (ROC) curves incorporating these biomarkers was developed for the auxiliary diagnosis of SCLC. Results After appropriate modification of the parameters, the GEP model was initially set up based on a training set of 115 SCLC patients and 125 normal controls for GEP model generation. Then the GEP was applied to the remaining 60 subjects (the test set) for model validation. GEP successfully discriminated 281 out of 300 cases, showing a correct classification rate for lung cancer patients of 93.75% (225/240) and 93.33% (56/60) for the training and test sets, respectively. Another GEP model incorporating four biomarkers, including CEA, NSE, LDH, and CRP, exhibited slightly lower detection sensitivity than the GEP model, including six biomarkers. We repeat the models on artificial neural network (ANN), and our results showed that the accuracy of GEP models were higher than that in ANN. GEP model incorporating six serum biomarkers performed by NSCLC patients and normal controls showed low accuracy than SCLC patients and was enough to prove that the GEP model is suitable for the SCLC patients. Conclusion We have developed a GEP model with high sensitivity and specificity for the auxiliary diagnosis of SCLC. This GEP model has the potential for the wide use

  1. Regulated anion secretion in cultured epithelia from Sertoli cells of immature rats

    PubMed Central

    Ko, W H; Chan, H C; Chew, S B; Wong, P Y D

    1998-01-01

    Cultured epithelia of Sertoli cells from prepubertal rats were grown on Matrigel-coated millipore filters for short-circuit current (Isc) measurements. Under basal conditions, these epithelia exhibited a ‘zero’ transepithelial potential difference, a ‘zero’ short-circuit current and a transepithelial resistance of 60 Ω cm2. Forskolin (100 μm) and 8-(4-chlorophenylthio)-cAMP (cpt-cAMP) (100 μm) added to the apical side stimulated the Isc (forskolin, peak ΔIsc = 1.32 ± 0.16 μA cm−1; cpt-cAMP, peak ΔIsc = 0.88 ± 0.16 μA cm−2). ATP (100 μm) added apically elicited a Isc response (peak ΔIsc = 6.45 ± 0.28 μA cm−2) which was similar in magnitude to that of 1 μm thapsigargin (peak ΔIsc = 6.09 ± 0.44 μA cm−2). The potency of the responses to other nucleotides: UTP ≥ ATP > ADP >> AMP = adenosine indicates the involvement of a mixture of P2Y receptors. Removal of extracellular Cl− and HCO3− reduced the Isc response to ATP by 70% and 40%, respectively. Removal of K+ had no effect, whereas removal of Na+ attenuated the Isc response. The response to ATP was insensitive to agents known to block anion secretion (except apical diphenylamine-2-carboxylate (DPC) and DIDS). The resistance to perturbation by pharmacological agents may be a unique property of the seminiferous epithelium. Whole-cell current recordings in cultured rat Sertoli cells demonstrated a DIDS-sensitive outwardly rectifying Cl− conductance with activating and inactivating characteristics at depolarizing and hyperpolarizing voltages, respectively. The stimulation of electrogenic ion transport by ATP may be part of a complex mechanism regulating fluid secretion by the testis. Cultured Sertoli cell epithelia are shown to provide a useful model to investigate transepithelial transport in the seminiferous epithelium. PMID:9763636

  2. A novel chimeric adenoassociated virus 2/human bocavirus 1 parvovirus vector efficiently transduces human airway epithelia.

    PubMed

    Yan, Ziying; Keiser, Nicholas W; Song, Yi; Deng, Xuefeng; Cheng, Fang; Qiu, Jianming; Engelhardt, John F

    2013-12-01

    Human bocavirus virus-1 (HBoV1), a newly discovered autonomous parvovirus with a 5,500 nt genome, efficiently infects human-polarized airway epithelia (HAE) from the apical membrane. We hypothesized that the larger genome and high airway tropism of HBoV1 would be ideal for creating a viral vector for lung gene therapy. To this end, we successfully generated recombinant HBoV1 (rHBoV1) from an open reading frames-disrupted rHBoV1 genome that efficiently transduces HAE from the apical surface. We next evaluated whether HBoV1 capsids could package oversized rAAV2 genomes. These studies created a rAAV2/HBoV1 chimeric virus (5.5 kb genome) capable of apically transducing HAE at 5.6- and 70-fold greater efficiency than rAAV1 or rAAV2 (4.7-kb genomes), respectively. Molecular studies demonstrated that viral uptake from the apical surface was significantly greater for rAAV2/HBoV1 than for rAAV2 or rAAV1, and that polarization of airway epithelial cells was required for HBoV1 capsid-mediated gene transfer. Furthermore, rAAV2/HBoV1-CFTR virus containing the full-length cystic fibrosis transmembrane conductance regulator (CFTR) gene coding sequence and the strong CBA promoter efficiently corrected CFTR-dependent chloride transport in cystic fibrosis (CF) HAE. In summary, using the combined advantages of AAV and HBoV1, we have developed a novel and promising viral vector for CF lung gene therapy and also potentially HBoV1 vaccine development. PMID:23896725

  3. Mechanisms controlling arrangements and movements of nuclei in pseudostratified epithelia.

    PubMed

    Lee, Hyun O; Norden, Caren

    2013-03-01

    During development, cells undergo complex rearrangements that contribute to the final tissue architecture. A characteristic arrangement found in rapidly expanding, highly proliferative tissues is pseudostratified epithelium, which features notably elongated cells with varied nuclear positions along the cell axis. Although anomalies in its structure are implicated in diseases like microcephaly, how pseudostratification is formed and maintained remains elusive. In this review, we focus on a typical feature of pseudostratified epithelia called interkinetic nuclear migration (INM), which describes dynamic movements of nuclei within the elongated cell bodies. We provide an overview of cytoskeletal components underlying INM in different systems, discuss current understanding of its kinetics and timing, and evaluate how conflicting results could be explained through developmental and evolutionary considerations. PMID:23266143

  4. Calcium signaling and the secretory activity of bile duct epithelia.

    PubMed

    Amaya, Maria Jimena; Nathanson, Michael H

    2014-06-01

    Cytosolic calcium (Cai(2+)) is a second messenger that is important for the regulation of secretion in many types of tissues. Bile duct epithelial cells, or cholangiocytes, are polarized epithelia that line the biliary tree in liver and are responsible for secretion of bicarbonate and other solutes into bile. Cai(2+) signaling plays an important role in the regulation of secretion by cholangiocytes, and this review discusses the machinery involved in the formation of Ca(2+) signals in cholangiocytes, along with the evidence that these signals regulate ductular secretion. Finally, this review discusses the evidence that impairments in cholangiocyte Ca(2+) signaling play a primary role in the pathogenesis of cholestatic disorders, in which hepatic bile secretion is impaired. PMID:24612866

  5. Adenovirus-delivered wwox inhibited lung cancer growth in vivo in a mouse model.

    PubMed

    Zhou, Y; Shou, F; Zhang, H; You, Q

    2016-01-01

    Lung cancer is the most prevalent and deadly malignancy worldwide. This study investigated the possibility of inhibiting lung cancer in vivo with adenovirus-delivered WW domain-containing oxidoreductase (wwox). The lung cancer model was established by inoculating A549 lung cancer cells into the pleural space of nude mice. The control or wwox adenovirus was injected into the pleural space 7 days after cell inoculation and 14 days after first injection. The tumor number and burdens were measured 2 weeks after second virus injection. The carcinoembryonic antigen (CEA) and alpha-feto protein (AFP) levels in pleural effusion were analyzed by enzyme-linked immunosorbent assay. Apoptosis, proliferation and angiogenesis of tumor cells were assessed by terminal deoxinucleotidyl transferase-mediated dUTP-fluorescein nick end labeling assay, proliferating cell nuclear antigen (PCNA) and CD31 staining, respectively. Ectopic wwox significantly reduced both the number and size of lung tumors accompanied by substantially lower CEA and AFP levels in pleural effusion. The expression levels of Bcl2, Bcl-xL, vascular endothelial growth factor, PCNA-positive and CD31-positive cells in the tumors were significantly decreased, whereas levels of p21 and p73 and apoptotic cells markedly increased in mice receiving the wwox virus. These data demonstrated that wwox delivered by adenovirus was able to inhibit the growth of lung cancer in vivo, indicating the potential of using wwox as a gene therapy agent for lung cancer. PMID:26516139

  6. Mouse lung infection model to assess Rhodococcus equi virulence and vaccine protection.

    PubMed

    González-Iglesias, Patricia; Scortti, Mariela; MacArthur, Iain; Hapeshi, Alexia; Rodriguez, Héctor; Prescott, John F; Vazquez-Boland, José A

    2014-08-01

    The pathogenic actinomycete Rhodococcus equi causes severe purulent lung infections in foals and immunocompromised people. Although relatively unsusceptible to R. equi, mice are widely used for in vivo studies with this pathogen. The most commonly employed mouse model is based on systemic (intravenous) infection and determination of R. equi burdens in spleen and liver. Here, we investigated the murine lung for experimental infection studies with R. equi. Using a 10(7)CFU intranasal challenge in BALB/c mice, virulent R. equi consistently survived in quantifiable numbers up to 10 days in the lungs whereas virulence-deficient R. equi bacteria were rapidly cleared. An internally controlled virulence assay was developed in which the test R. equi strains are co-inoculated and monitored in the same mouse. Isogenic R. equi bacteria lacking either the plasmid vapA gene or the entire virulence plasmid were compared using this competitive assay. Both strains showed no significant differences in in vivo fitness in the lung, indicating that the single loss of the virulence factor VapA was sufficient to account for the full attenuation seen in the absence of the virulence plasmid. To test the adequacy of the lung infection model for monitoring R. equi vaccine efficacy, BALB/c mice were immunized with live R. equi and challenged intranasally. Vaccination conferred protection against acute pulmonary challenge with virulent R. equi. Our data indicate that the murine lung infection model provides a useful tool for both R. equi virulence and vaccine studies. PMID:24852140

  7. Model-based risk assessment for motion effects in 3D radiotherapy of lung tumors

    NASA Astrophysics Data System (ADS)

    Werner, René; Ehrhardt, Jan; Schmidt-Richberg, Alexander; Handels, Heinz

    2012-02-01

    Although 4D CT imaging becomes available in an increasing number of radiotherapy facilities, 3D imaging and planning is still standard in current clinical practice. In particular for lung tumors, respiratory motion is a known source of uncertainty and should be accounted for during radiotherapy planning - which is difficult by using only a 3D planning CT. In this contribution, we propose applying a statistical lung motion model to predict patients' motion patterns and to estimate dosimetric motion effects in lung tumor radiotherapy if only 3D images are available. Being generated based on 4D CT images of patients with unimpaired lung motion, the model tends to overestimate lung tumor motion. It therefore promises conservative risk assessment regarding tumor dose coverage. This is exemplarily evaluated using treatment plans of lung tumor patients with different tumor motion patterns and for two treatment modalities (conventional 3D conformal radiotherapy and step-&- shoot intensity modulated radiotherapy). For the test cases, 4D CT images are available. Thus, also a standard registration-based 4D dose calculation is performed, which serves as reference to judge plausibility of the modelbased 4D dose calculation. It will be shown that, if combined with an additional simple patient-specific breathing surrogate measurement (here: spirometry), the model-based dose calculation provides reasonable risk assessment of respiratory motion effects.

  8. Progressive genomic instability in the FVB/KrasLA2 mouse model of lung cancer

    PubMed Central

    To, Minh D.; Quigley, David A.; Mao, Jian-Hua; Rosario, Reyno Del; Hsu, Jeff; Hodgson, Graeme; Jacks, Tyler; Balmain, Allan

    2011-01-01

    Alterations in DNA copy number contribute to the development and progression of cancers and are common in epithelial tumors. We have used array Comparative Genomic Hybridization (aCGH) to visualize DNA copy number alterations across the genomes of lung tumors in the KrasLA2 model of lung cancer. Copy number gain involving the Kras locus, as focal amplification or whole chromosome gain, is the most common alteration in these tumors, and with a prevalence that increased significantly with increasing tumor size. Furthermore, Kras amplification was the only major genomic event among the smallest lung tumors, suggesting that this alteration occurs early during the development of mutant Kras driven lung cancers. Recurring gains and deletions of other chromosomes occur progressively more frequently among larger tumors. These results are in contrast to a previous aCGH analysis of lung tumors from KrasLA2 mice on a mixed genetic background, in which relatively few DNA copy number alterations were observed regardless of tumor size. Our model features the KrasLA2 allele on the inbred FVB/N mouse strain, and in this genetic background there is a highly statistically significant increase in level of genomic instability with increasing tumor size. These data suggest that recurring DNA copy alterations are important for tumor progression in the KrasLA2 model of lung cancer, and that the requirement for these alterations may be dependent on the genetic background of the mouse strain. PMID:21807965

  9. Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments.

    PubMed

    Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B; Wang, Ya

    2016-06-01

    Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk. PMID:27345200

  10. Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B.; Wang, Ya

    2016-06-01

    Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk.

  11. Animal models of ex vivo lung perfusion as a platform for transplantation research

    PubMed Central

    Nelson, Kevin; Bobba, Christopher; Ghadiali, Samir; Jr, Don Hayes; Black, Sylvester M; Whitson, Bryan A

    2014-01-01

    Ex vivo lung perfusion (EVLP) is a powerful experimental model for isolated lung research. EVLP allows for the lungs to be manipulated and characterized in an external environment so that the effect of specific ventilation/perfusion variables can be studied independent of other confounding physiologic contributions. At the same time, EVLP allows for normal organ level function and real-time monitoring of pulmonary physiology and mechanics. As a result, this technique provides unique advantages over in vivo and in vitro models. Small and large animal models of EVLP have been developed and each of these models has their strengths and weaknesses. In this manuscript, we provide insight into the relative strengths of each model and describe how the development of advanced EVLP protocols is leading to a novel experimental platform that can be used to answer critical questions in pulmonary physiology and transplant medicine. PMID:24977117

  12. Animal models of ex vivo lung perfusion as a platform for transplantation research.

    PubMed

    Nelson, Kevin; Bobba, Christopher; Ghadiali, Samir; Hayes, Don; Black, Sylvester M; Whitson, Bryan A

    2014-05-20

    Ex vivo lung perfusion (EVLP) is a powerful experimental model for isolated lung research. EVLP allows for the lungs to be manipulated and characterized in an external environment so that the effect of specific ventilation/perfusion variables can be studied independent of other confounding physiologic contributions. At the same time, EVLP allows for normal organ level function and real-time monitoring of pulmonary physiology and mechanics. As a result, this technique provides unique advantages over in vivo and in vitro models. Small and large animal models of EVLP have been developed and each of these models has their strengths and weaknesses. In this manuscript, we provide insight into the relative strengths of each model and describe how the development of advanced EVLP protocols is leading to a novel experimental platform that can be used to answer critical questions in pulmonary physiology and transplant medicine. PMID:24977117

  13. Glucocorticoid Clearance and Metabolite Profiling in an In Vitro Human Airway Epithelium Lung Model.

    PubMed

    Rivera-Burgos, Dinelia; Sarkar, Ujjal; Lever, Amanda R; Avram, Michael J; Coppeta, Jonathan R; Wishnok, John S; Borenstein, Jeffrey T; Tannenbaum, Steven R

    2016-02-01

    The emergence of microphysiologic epithelial lung models using human cells in a physiologically relevant microenvironment has the potential to be a powerful tool for preclinical drug development and to improve predictive power regarding in vivo drug clearance. In this study, an in vitro model of the airway comprising human primary lung epithelial cells cultured in a microfluidic platform was used to establish a physiologic state and to observe metabolic changes as a function of glucocorticoid exposure. Evaluation of mucus production rate and barrier function, along with lung-specific markers, demonstrated that the lungs maintained a differentiated phenotype. Initial concentrations of 100 nM hydrocortisone (HC) and 30 nM cortisone (C) were used to evaluate drug clearance and metabolite production. Measurements made using ultra-high-performance liquid chromatography and high-mass-accuracy mass spectrometry indicated that HC metabolism resulted in the production of C and dihydrocortisone (diHC). When the airway model was exposed to C, diHC was identified; however, no conversion to HC was observed. Multicompartmental modeling was used to characterize the lung bioreactor data, and pharmacokinetic parameters, including elimination clearance and elimination half-life, were estimated. Polymerse chain reaction data confirmed overexpression of 11-β hydroxysteroid dehydrogenase 2 (11βHSD2) over 11βHSD1, which is biologically relevant to human lung. Faster metabolism was observed relative to a static model on elevated rates of C and diHC formation. Overall, our results demonstrate that this lung airway model has been successfully developed and could interact with other human tissues in vitro to better predict in vivo drug behavior. PMID:26586376

  14. The MGH-HMS Lung Cancer Policy Model: Tobacco Control versus Screening

    PubMed Central

    McMahon, Pamela M.; Kong, Chung Yin; Johnson, Bruce E.; Weinstein, Milton C.; Weeks, Jane C.; Tramontano, Angela C.; Cipriano, Lauren E.; Bouzan, Colleen; Gazelle, G. Scott

    2012-01-01

    Background The natural history model underlying the MGH Lung Cancer Policy Model (LCPM) does not include the two-stage clonal expansion model employed in other CISNET lung models. We used the LCPM to predict numbers of U.S. lung cancer deaths for ages 30–84 between 1975 and 2000 under 4 scenarios as part of the comparative modeling analysis described in this monograph. Methods The LCPM is a comprehensive microsimulation model of lung cancer development, progression, detection, treatment, and survival. Individual-level patient histories are aggregated to estimate cohort or population-level outcomes. Lung cancer states are defined according to underlying disease variables, test results, and clinical events. By simulating detailed clinical procedures, the LCPM can predict benefits and harms attributable to a variety of patient management practices, including annual screening programs. Results Under the scenario of observed smoking patterns, predicted numbers of deaths from the calibrated LCPM were within 2% of observed over all years (1975–2000). The LCPM estimated that historical tobacco control policies achieved 28.6% (25.2% in men, 30.5% in women) of the potential reduction in U.S. lung cancer deaths had smoking had been eliminated entirely. The hypothetical adoption in 1975 of annual helical CT screening of all persons aged 55–74 with at least 30 pack-years of cigarette exposure to historical tobacco control would have yielded a proportion realized of 39.0% (42.0% in men, 33.3% in women). Conclusions The adoption of annual screening would have prevented less than half as many lung cancer deaths as the elimination of cigarette smoking. PMID:22882882

  15. HOSVD-Based 3D Active Appearance Model: Segmentation of Lung Fields in CT Images.

    PubMed

    Wang, Qingzhu; Kang, Wanjun; Hu, Haihui; Wang, Bin

    2016-07-01

    An Active Appearance Model (AAM) is a computer vision model which can be used to effectively segment lung fields in CT images. However, the fitting result is often inadequate when the lungs are affected by high-density pathologies. To overcome this problem, we propose a Higher-order Singular Value Decomposition (HOSVD)-based Three-dimensional (3D) AAM. An evaluation was performed on 310 diseased lungs form the Lung Image Database Consortium Image Collection. Other contemporary AAMs operate directly on patterns represented by vectors, i.e., before applying the AAM to a 3D lung volume,it has to be vectorized first into a vector pattern by some technique like concatenation. However, some implicit structural or local contextual information may be lost in this transformation. According to the nature of the 3D lung volume, HOSVD is introduced to represent and process the lung in tensor space. Our method can not only directly operate on the original 3D tensor patterns, but also efficiently reduce the computer memory usage. The evaluation resulted in an average Dice coefficient of 97.0 % ± 0.59 %, a mean absolute surface distance error of 1.0403 ± 0.5716 mm, a mean border positioning errors of 0.9187 ± 0.5381 pixel, and a Hausdorff Distance of 20.4064 ± 4.3855, respectively. Experimental results showed that our methods delivered significant and better segmentation results, compared with the three other model-based lung segmentation approaches, namely 3D Snake, 3D ASM and 3D AAM. PMID:27277277

  16. Early Impairment of Lung Mechanics in a Murine Model of Marfan Syndrome

    PubMed Central

    Uriarte, Juan J.; Meirelles, Thayna; Gorbenko del Blanco, Darya; Nonaka, Paula N.; Campillo, Noelia; Sarri, Elisabet; Navajas, Daniel; Egea, Gustavo; Farré, Ramon

    2016-01-01

    Early morbidity and mortality in patients with Marfan syndrome (MFS) -a connective tissue disease caused by mutations in fibrillin-1 gene- are mainly caused by aorta aneurysm and rupture. However, the increase in the life expectancy of MFS patients recently achieved by reparatory surgery promotes clinical manifestations in other organs. Although some studies have reported respiratory alterations in MFS, our knowledge of how this connective tissue disease modifies lung mechanics is scarce. Hence, we assessed whether the stiffness of the whole lung and of its extracellular matrix (ECM) is affected in a well-characterized MFS mouse model (FBN1C1039G/+). The stiffness of the whole lung and of its ECM were measured by conventional mechanical ventilation and atomic force microscopy, respectively. We studied 5-week and 9-month old mice, whose ages are representative of early and late stages of the disease. At both ages, the lungs of MFS mice were significantly more compliant than in wild type (WT) mice. By contrast, no significant differences were found in local lung ECM stiffness. Moreover, histopathological lung evaluation showed a clear emphysematous-like pattern in MFS mice since alveolar space enlargement was significantly increased compared with WT mice. These data suggest that the mechanism explaining the increased lung compliance in MFS is not a direct consequence of reduced ECM stiffness, but an emphysema-like alteration in the 3D structural organization of the lung. Since lung alterations in MFS are almost fully manifested at an early age, it is suggested that respiratory monitoring could provide early biomarkers for diagnosis and/or follow-up of patients with the Marfan syndrome. PMID:27003297

  17. Early Impairment of Lung Mechanics in a Murine Model of Marfan Syndrome.

    PubMed

    Uriarte, Juan J; Meirelles, Thayna; Gorbenko Del Blanco, Darya; Nonaka, Paula N; Campillo, Noelia; Sarri, Elisabet; Navajas, Daniel; Egea, Gustavo; Farré, Ramon

    2016-01-01

    Early morbidity and mortality in patients with Marfan syndrome (MFS) -a connective tissue disease caused by mutations in fibrillin-1 gene- are mainly caused by aorta aneurysm and rupture. However, the increase in the life expectancy of MFS patients recently achieved by reparatory surgery promotes clinical manifestations in other organs. Although some studies have reported respiratory alterations in MFS, our knowledge of how this connective tissue disease modifies lung mechanics is scarce. Hence, we assessed whether the stiffness of the whole lung and of its extracellular matrix (ECM) is affected in a well-characterized MFS mouse model (FBN1C1039G/+). The stiffness of the whole lung and of its ECM were measured by conventional mechanical ventilation and atomic force microscopy, respectively. We studied 5-week and 9-month old mice, whose ages are representative of early and late stages of the disease. At both ages, the lungs of MFS mice were significantly more compliant than in wild type (WT) mice. By contrast, no significant differences were found in local lung ECM stiffness. Moreover, histopathological lung evaluation showed a clear emphysematous-like pattern in MFS mice since alveolar space enlargement was significantly increased compared with WT mice. These data suggest that the mechanism explaining the increased lung compliance in MFS is not a direct consequence of reduced ECM stiffness, but an emphysema-like alteration in the 3D structural organization of the lung. Since lung alterations in MFS are almost fully manifested at an early age, it is suggested that respiratory monitoring could provide early biomarkers for diagnosis and/or follow-up of patients with the Marfan syndrome. PMID:27003297

  18. Geometric dose prediction model for hemithoracic intensity-modulated radiation therapy in mesothelioma patients with two intact lungs.

    PubMed

    Kuo, LiCheng; Yorke, Ellen D; Dumane, Vishruta A; Foster, Amanda; Zhang, Zhigang; Mechalakos, James G; Wu, Abraham J; Rosenzweig, Kenneth E; Rimner, Andreas

    2016-01-01

    The presence of two intact lungs makes it challenging to reach a tumoricidal dose with hemithoracic pleural intensity-modulated radiation therapy (IMRT) in patients with malignant pleural mesothelioma (MPM) who underwent pleurectomy/decor-tications or have unresectable disease. We developed an anatomy-based model to predict attainable prescription dose before starting optimization. Fifty-six clinically delivered IMRT plans were analyzed regarding correlation of prescription dose and individual and total lung volumes, planning target volume (PTV), ipsilateral normal lung volume and ratios: contralateral/ipsilateral lung (CIVR); contralateral lung/PTV (CPVR); ipsilateral lung /PTV (IPVR); ipsilateral normal lung /total lung (INTLVR); ipsilateral normal lung/PTV (INLPVR). Spearman's rank correlation and Fisher's exact test were used. Correlation between mean ipsilateral lung dose (MILD) and these volume ratios and between prescription dose and single lung mean doses were studied. The prediction models were validated in 23 subsequent MPM patients. CIVR showed the strongest correlation with dose (R = 0.603, p < 0.001) and accurately predicted prescription dose in the validation cases. INLPVR and MILD as well as MILD and prescription dose were significantly correlated (R = -0.784, p < 0.001 and R = 0.554, p < 0.001, respectively) in the training and validation cases. Parameters obtainable directly from planning scan anatomy predict achievable prescription doses for hemithoracic IMRT treatment of MPM patients with two intact lungs. PMID:27167294

  19. Characterization of wild-type and deltaF508 cystic fibrosis transmembrane regulator in human respiratory epithelia.

    PubMed

    Kreda, Silvia M; Mall, Marcus; Mengos, April; Rochelle, Lori; Yankaskas, James; Riordan, John R; Boucher, Richard C

    2005-05-01

    Previous studies in native tissues have produced conflicting data on the localization and metabolic fate of WT and deltaF508 cystic fibrosis transmembrane regulator (CFTR) in the lung. Combining immunocytochemical and biochemical studies utilizing new high-affinity CFTR mAbs with ion transport assays, we examined both 1) the cell type and region specific expression of CFTR in normal airways and 2) the metabolic fate of deltaF508 CFTR and associated ERM proteins in the cystic fibrosis lung. Studies of lungs from a large number of normal subjects revealed that WT CFTR protein localized to the apical membrane of ciliated cells within the superficial epithelium and gland ducts. In contrast, other cell types in the superficial, gland acinar, and alveolar epithelia expressed little WT CFTR protein. No deltaF508 CFTR mature protein or function could be detected in airway specimens freshly excised from a large number of deltaF508 homozygous subjects, despite an intact ERM complex. In sum, our data demonstrate that WT CFTR is predominantly expressed in ciliated cells, and deltaF508 CFTR pathogenesis in native tissues, like heterologous cells, reflects loss of normal protein processing. PMID:15716351

  20. Characterization of Wild-Type and ΔF508 Cystic Fibrosis Transmembrane Regulator in Human Respiratory Epithelia

    PubMed Central

    Kreda, Silvia M.; Mall, Marcus; Mengos, April; Rochelle, Lori; Yankaskas, James; Riordan, John R.; Boucher, Richard C.

    2005-01-01

    Previous studies in native tissues have produced conflicting data on the localization and metabolic fate of WT and ΔF508 cystic fibrosis transmembrane regulator (CFTR) in the lung. Combining immunocytochemical and biochemical studies utilizing new high-affinity CFTR mAbs with ion transport assays, we examined both 1) the cell type and region specific expression of CFTR in normal airways and 2) the metabolic fate of ΔF508 CFTR and associated ERM proteins in the cystic fibrosis lung. Studies of lungs from a large number of normal subjects revealed that WT CFTR protein localized to the apical membrane of ciliated cells within the superficial epithelium and gland ducts. In contrast, other cell types in the superficial, gland acinar, and alveolar epithelia expressed little WT CFTR protein. No ΔF508 CFTR mature protein or function could be detected in airway specimens freshly excised from a large number of ΔF508 homozygous subjects, despite an intact ERM complex. In sum, our data demonstrate that WT CFTR is predominantly expressed in ciliated cells, and ΔF508 CFTR pathogenesis in native tissues, like heterologous cells, reflects loss of normal protein processing. PMID:15716351

  1. Comparing histone deacetylase inhibitor responses in genetically engineered mouse lung cancer models and a window of opportunity trial in patients with lung cancer.

    PubMed

    Ma, Tian; Galimberti, Fabrizio; Erkmen, Cherie P; Memoli, Vincent; Chinyengetere, Fadzai; Sempere, Lorenzo; Beumer, Jan H; Anyang, Bean N; Nugent, William; Johnstone, David; Tsongalis, Gregory J; Kurie, Jonathan M; Li, Hua; Direnzo, James; Guo, Yongli; Freemantle, Sarah J; Dragnev, Konstantin H; Dmitrovsky, Ethan

    2013-08-01

    Histone deacetylase inhibitor (HDACi; vorinostat) responses were studied in murine and human lung cancer cell lines and genetically engineered mouse lung cancer models. Findings were compared with a window of opportunity trial in aerodigestive tract cancers. In human (HOP62, H522, and H23) and murine transgenic (ED-1, ED-2, LKR-13, and 393P, driven, respectively, by cyclin E, degradation-resistant cyclin E, KRAS, or KRAS/p53) lung cancer cell lines, vorinostat reduced growth, cyclin D1, and cyclin E levels, but induced p27, histone acetylation, and apoptosis. Other biomarkers also changed. Findings from transgenic murine lung cancer models were integrated with those from a window of opportunity trial that measured vorinostat pharmacodynamic responses in pre- versus posttreatment tumor biopsies. Vorinostat repressed cyclin D1 and cyclin E expression in murine transgenic lung cancers and significantly reduced lung cancers in syngeneic mice. Vorinostat also reduced cyclin D1 and cyclin E expression, but increased p27 levels in post- versus pretreatment human lung cancer biopsies. Notably, necrotic and inflammatory responses appeared in posttreatment biopsies. These depended on intratumoral HDACi levels. Therefore, HDACi treatments of murine genetically engineered lung cancer models exert similar responses (growth inhibition and changes in gene expression) as observed in lung cancer cell lines. Moreover, enhanced pharmacodynamic responses occurred in the window of opportunity trial, providing additional markers of response that can be evaluated in subsequent HDACi trials. Thus, combining murine and human HDACi trials is a strategy to translate preclinical HDACi treatment outcomes into the clinic. This study uncovered clinically tractable mechanisms to engage in future HDACi trials. PMID:23686769

  2. A novel dual ex vivo lung perfusion technique improves immediate outcomes in an experimental model of lung transplantation.

    PubMed

    Tanaka, Y; Noda, K; Isse, K; Tobita, K; Maniwa, Y; Bhama, J K; D'Cunha, J; Bermudez, C A; Luketich, J D; Shigemura, N

    2015-05-01

    The lungs are dually perfused by the pulmonary artery and the bronchial arteries. This study aimed to test the feasibility of dual-perfusion techniques with the bronchial artery circulation and pulmonary artery circulation synchronously perfused using ex vivo lung perfusion (EVLP) and evaluate the effects of dual-perfusion on posttransplant lung graft function. Using rat heart-lung blocks, we developed a dual-perfusion EVLP circuit (dual-EVLP), and compared cellular metabolism, expression of inflammatory mediators, and posttransplant graft function in lung allografts maintained with dual-EVLP, standard-EVLP, or cold static preservation. The microvasculature in lung grafts after transplant was objectively evaluated using microcomputed tomography angiography. Lung grafts subjected to dual-EVLP exhibited significantly better lung graft function with reduced proinflammatory profiles and more mitochondrial biogenesis, leading to better posttransplant function and compliance, as compared with standard-EVLP or static cold preservation. Interestingly, lung grafts maintained on dual-EVLP exhibited remarkably increased microvasculature and perfusion as compared with lungs maintained on standard-EVLP. Our results suggest that lung grafts can be perfused and preserved using dual-perfusion EVLP techniques that contribute to better graft function by reducing proinflammatory profiles and activating mitochondrial respiration. Dual-EVLP also yields better posttransplant graft function through increased microvasculature and better perfusion of the lung grafts after transplantation. PMID:25777770

  3. A Method for Lung Boundary Correction Using Split Bregman Method and Geometric Active Contour Model.

    PubMed

    Feng, Changli; Zhang, Jianxun; Liang, Rui

    2015-01-01

    In order to get the extracted lung region from CT images more accurately, a model that contains lung region extraction and edge boundary correction is proposed. Firstly, a new edge detection function is presented with the help of the classic structure tensor theory. Secondly, the initial lung mask is automatically extracted by an improved active contour model which combines the global intensity information, local intensity information, the new edge information, and an adaptive weight. It is worth noting that the objective function of the improved model is converted to a convex model, which makes the proposed model get the global minimum. Then, the central airway was excluded according to the spatial context messages and the position relationship between every segmented region and the rib. Thirdly, a mesh and the fractal theory are used to detect the boundary that surrounds the juxtapleural nodule. Finally, the geometric active contour model is employed to correct the detected boundary and reinclude juxtapleural nodules. We also evaluated the performance of the proposed segmentation and correction model by comparing with their popular counterparts. Efficient computing capability and robustness property prove that our model can correct the lung boundary reliably and reproducibly. PMID:26089976

  4. Characterization of free breathing patterns with 5D lung motion model

    SciTech Connect

    Zhao Tianyu; Lu Wei; Yang Deshan; Mutic, Sasa; Noel, Camille E.; Parikh, Parag J.; Bradley, Jeffrey D.; Low, Daniel A.

    2009-11-15

    Purpose: To determine the quiet respiration breathing motion model parameters for lung cancer and nonlung cancer patients. Methods: 49 free breathing patient 4DCT image datasets (25 scans, cine mode) were collected with simultaneous quantitative spirometry. A cross-correlation registration technique was employed to track the lung tissue motion between scans. The registration results were applied to a lung motion model: X-vector=X-vector{sub 0}+{alpha}-vector{beta}-vector f, where X-vector is the position of a piece of tissue located at reference position X-vector{sub 0} during a reference breathing phase (zero tidal volume v, zero airflow f). {alpha}-vector is a parameter that characterizes the motion due to air filling (motion as a function of tidal volume v) and {beta}-vector is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation that causes lung motion hysteresis (motion as a function of airflow f). The parameters {alpha}-vector and {beta}-vector together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The {alpha}-vector and {beta}-vector distributions were examined for each patient to determine overall general patterns and interpatient pattern variations. Results: For 44 patients, the greatest values of |{alpha}-vector| were observed in the inferior and posterior lungs. For the rest of the patients, |{alpha}-vector| reached its maximum in the anterior lung in three patients and the lateral lung in two patients. The hysteresis motion {beta}-vector had greater variability, but for the majority of patients, |{beta}-vector| was largest in the lateral lungs. Conclusions: This is the first report of the three-dimensional breathing motion model parameters for a large cohort of patients. The model has the potential for noninvasively predicting lung motion. The majority of patients exhibited similar |{alpha}-vector| maps

  5. Nerve growth factor enhances Clara cell proliferation after lung injury.

    PubMed

    Sonar, S S; Schwinge, D; Kilic, A; Yildirim, A O; Conrad, M L; Seidler, K; Müller, B; Renz, H; Nockher, W A

    2010-07-01

    The lung epithelia facilitate wound closure by secretion of various cytokines and growth factors. Nerve growth factor (NGF) has been well described in airway inflammation; however, its likely role in lung repair has not been examined thus far. To investigate the repair function of NGF, experiments were performed in vitro using cultured alveolar epithelial cells and in vivo using a naphthalene-induced model of Clara epithelial cell injury. Both in vitro and in vivo experiments revealed airway epithelial cell proliferation following injury to be dependent on NGF and the expression of its receptor, tropomyosin-receptor-kinase A. Additionally, NGF also augmented in vitro migration of alveolar type II cells. In vivo, transgenic mice over-expressing NGF in Clara cells (NGFtg) did not reveal any proliferation or alteration in Clara cell phenotype. However, following Clara cell specific injury, proliferation was increased in NGFtg and impaired upon inhibition of NGF. Furthermore, NGF also promoted the expression of collagen I and fibronectin in vitro and in vivo during repair, where significantly higher levels were measured in re-epithelialising NGFtg mice. Our study demonstrates that NGF promotes the proliferation of lung epithelium in vitro and the renewal of Clara cells following lung injury in vivo. PMID:20075049

  6. Effects of Chinese medicinal herbs on a rat model of chronic Pseudomonas aeruginosa lung infection.

    PubMed

    Song, Z; Johansen, H K; Moser, C; Høiby, N

    1996-05-01

    The aim of the study was to evaluate the effects of two kinds of Chinese medicinal herbs, Isatis tinctoria L (ITL) and Daphne giraldii Nitsche (DGN), on a rat model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis (CF). Compared to the control group, both drugs were able to reduce the incidence of lung abscess (p < 0.05) and to decrease the severity of the macroscopic pathology in lungs (p < 0.05). In the great majority of the rats, the herbs altered the inflammatory response in the lungs from an acute type inflammation, dominated by polymorphonuclear leukocytes (PMN), to a chronic type inflammation, dominated by mononuclear leukocytes (MN). DGN also improved the clearance of P. aeruginosa from the lungs (p < 0.03) compared with the control group. There were no significant differences between the control group and the two herbal groups with regard to serum IgG and IgA anti-P. aeruginosa sonicate antibodies. However, the IgM concentration in the ITL group was significantly lower than in the control group (p < 0.03). These results suggest that the two medicinal herbs might be helpful to CF patients with chronic P. aeruginosa lung infection, DGN being the most favorable. PMID:8703440

  7. Immunomodulatory Effects of Mixed Hematopoietic Chimerism: Immune Tolerance in Canine Model of Lung Transplantation

    PubMed Central

    Nash;, Richard A.; Yunosov;, Murad; Abrams;, Kraig; Hwang;, Billanna; Castilla-Llorente;, Cristina; Chen;, Peter; Farivar;, Alexander S.; Georges;, George E.; Hackman;, Robert C.; Lamm;, Wayne J.E.; Lesnikova;, Marina; Ochs;, Hans D.; Randolph-Habecker;, Julie; Ziegler;, Stephen F.; Storb;, Rainer; Storer;, Barry; Madtes;, David K.; Glenny;, Robb; Mulligan, Michael S.

    2010-01-01

    Long-term survival after lung transplantation is limited by acute and chronic graft rejection. Induction of immune tolerance by first establishing mixed hematopoietic chimerism (MC) is a promising strategy to improve outcomes. In a preclinical canine model, stable MC was established in recipients after reduced-intensity conditioning and hematopoietic cell transplantation from a DLA-identical donor. Delayed lung transplantation was performed from the stem cell donor without pharmacological immunosuppression. Lung graft survival without loss of function was prolonged in chimeric (n=5) vs. nonchimeric (n=7) recipients (p≤0.05, Fisher’s test). There were histological changes consistent with low grade rejection in 3/5 of the lung grafts in chimeric recipients at ≥1 year. Chimeric recipients after lung transplantation had a normal immune response to a T-dependent antigen. Compared to normal dogs, there were significant increases of CD4+INFγ+, CD4+IL-4+ and CD8+ INFγ+ T-cell subsets in the blood (p <0.0001 for each of the 3 T-cell subsets). Markers for regulatory T-cell subsets including foxP3, IL10 and TGFβ were also increased in CD3+ T cells from the blood and peripheral tissues of chimeric recipients after lung transplantation. Establishing MC is immunomodulatory and observed changes were consistent with activation of both the effector and regulatory immune response. PMID:19422333

  8. Effects of anesthetic regimes on inflammatory responses in a rat model of acute lung injury

    PubMed Central

    Fortis, Spyridon; Spieth, Peter M.; Lu, Wei-Yang; Parotto, Matteo; Haitsma, Jack J; Slutsky, Arthur S.; Zhong, Nanshan; Mazer, C. David; Zhang, Haibo

    2016-01-01

    Background Gamma amino butyric acid (GABA) is the major inhibitory neurotransmitter through activation of GABA receptors. Volatile anesthetics activate type A (GABAA) receptors resulting in inhibition of synaptic transmission. Lung epithelial cells have been recently found to express GABAA receptors that exert anti-inflammatory properties. We hypothesized that the volatile anesthetic sevoflurane (SEVO) attenuates lung inflammation through activation of lung epithelial GABAA receptors. Methods Sprague-Dawley rats were anesthetized with SEVO or ketamine/xylazine (KX). Acute lung inflammation was induced by intratracheal instillation of endotoxin, followed by mechanical ventilation for 4 h at a tidal volume of 15 mL/kg without positive end-expiratory pressure (two-hit lung injury model). To examine the specific effects of GABA, healthy human bronchial epithelial cells (BEAS-2B) were challenged with endotoxin in the presence and absence of GABA with and without addition of the GABAA receptor antagonist picrotoxin. Results Anesthesia with SEVO improved oxygenation and reduced pulmonary cytokine responses compared to KX. This phenomenon was associated with increased expression of the π subunit of GABAA receptors and glutamic acid decarboxylase (GAD). The endotoxin-induced cytokine release from BEAS-2B cells was attenuated by the treatment with GABA, which was reversed by the administration of picrotoxin. Conclusion Anesthesia with SEVO suppresses pulmonary inflammation thus protects the lung from the two-hit injury. The anti-inflammatory effect of SEVO is likely due to activation of pulmonary GABAA signaling pathways. PMID:22711173

  9. Misexpression of ELF5 Disrupts Lung Branching and Inhibits Epithelial Differentiation

    PubMed Central

    Metzger, David E.; Stahlman, Mildred T.; Shannon, John M.

    2008-01-01

    ELF5, an Ets family transcription factor found exclusively in epithelial cells, is expressed in the distal lung epithelium during embryogenesis, then becomes restricted to proximal airways at the end of gestation and postnatally. To test the hypothesis that ELF5 represses distal epithelial differentiation, we generated a transgenic mouse model in which a doxycycline inducible HA-tagged mouse Elf5 transgene was placed under the control of the lung epithelium-specific human SFTPC promoter. We found that expressing high levels of ELF5 during early lung development disrupted branching morphogenesis and produced a dilated epithelium. The effects of ELF5 on morphogenesis were stage dependent, since inducing the transgene on E16.5 had no effect on branching. ELF5 reduced expression of the distal lung epithelial differentiation markers Erm, Napsa and Sftpc, and type II cell ultrastructural differentiation was immature. ELF5 overexpression did not induce the proximal airway epithelial markers Ccsp and Foxj1, but did induce expression of p63, a marker of basal cells in the trachea and esophagus. High ELF5 levels also induced the expression of genes found in other endodermal epithelia but not normally associated with the lung. These results suggest that precise levels of ELF5 regulate the specification and differentiation of epithelial cells in the lung. PMID:18544451

  10. Lung tumor promotion by chromium-containing welding particulate matter in a mouse model

    PubMed Central

    2013-01-01

    Background Epidemiology suggests that occupational exposure to welding particulate matter (PM) may increase lung cancer risk. However, animal studies are lacking to conclusively link welding with an increased risk. PM derived from stainless steel (SS) welding contains carcinogenic metals such as hexavalent chromium and nickel. We hypothesized that welding PM may act as a tumor promoter and increase lung tumor multiplicity in vivo. Therefore, the capacity of chromium-containing gas metal arc (GMA)-SS welding PM to promote lung tumors was evaluated using a two-stage (initiation-promotion) model in lung tumor susceptible A/J mice. Methods Male mice (n = 28-30/group) were treated either with the initiator 3-methylcholanthrene (MCA;10 μg/g; IP) or vehicle (corn oil) followed by 5 weekly pharyngeal aspirations of GMA-SS (340 or 680 μg/exposure) or PBS. Lung tumors were enumerated at 30 weeks post-initiation. Results MCA initiation followed by GMA-SS welding PM exposure promoted tumor multiplicity in both the low (12.1 ± 1.5 tumors/mouse) and high (14.0 ± 1.8 tumors/mouse) exposure groups significantly above MCA/sham (4.77 ± 0.7 tumors/mouse; p = 0.0001). Multiplicity was also highly significant (p < 0.004) across all individual lung regions of GMA-SS-exposed mice. No exposure effects were found in the corn oil groups at 30 weeks. Histopathology confirmed the gross findings and revealed increased inflammation and a greater number of malignant lesions in the MCA/welding PM-exposed groups. Conclusions GMA-SS welding PM acts as a lung tumor promoter in vivo. Thus, this study provides animal evidence to support the epidemiological data that show welders have an increased lung cancer risk. PMID:24107379

  11. Method of Isolated Ex Vivo Lung Perfusion in a Rat Model: Lessons Learned from Developing a Rat EVLP Program

    PubMed Central

    Nelson, Kevin; Bobba, Christopher; Eren, Emre; Spata, Tyler; Tadres, Malak; Hayes,, Don; Black, Sylvester M.

    2015-01-01

    The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and “pearls of wisdom”/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible. PMID:25741794

  12. Method of isolated ex vivo lung perfusion in a rat model: lessons learned from developing a rat EVLP program.

    PubMed

    Nelson, Kevin; Bobba, Christopher; Eren, Emre; Spata, Tyler; Tadres, Malak; Hayes, Don; Black, Sylvester M; Ghadiali, Samir; Whitson, Bryan A

    2015-01-01

    The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and "pearls of wisdom"/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible. PMID:25741794

  13. Lung dosimetry and risk assessment of nanoparticles: Evaluating and extending current models in rats and humans

    SciTech Connect

    Kuempel, E.D.; Tran, C.L.; Castranova, V.; Bailer, A.J.

    2006-09-15

    Risk assessment of occupational exposure to nanomaterials is needed. Human data are limited, but quantitative data are available from rodent studies. To use these data in risk assessment, a scientifically reasonable approach for extrapolating the rodent data to humans is required. One approach is allometric adjustment for species differences in the relationship between airborne exposure and internal dose. Another approach is lung dosimetry modeling, which provides a biologically-based, mechanistic method to extrapolate doses from animals to humans. However, current mass-based lung dosimetry models may not fully account for differences in the clearance and translocation of nanoparticles. In this article, key steps in quantitative risk assessment are illustrated, using dose-response data in rats chronically exposed to either fine or ultrafine titanium dioxide (TiO{sub 2}), carbon black (CB), or diesel exhaust particulate (DEP). The rat-based estimates of the working lifetime airborne concentrations associated with 0.1% excess risk of lung cancer are approximately 0.07 to 0.3 mg/m{sup 3} for ultrafine TiO{sub 2}, CB, or DEP, and 0.7 to 1.3 mg/m{sup 3} for fine TiO{sub 2}. Comparison of observed versus model-predicted lung burdens in rats shows that the dosimetry models predict reasonably well the retained mass lung burdens of fine or ultrafine poorly soluble particles in rats exposed by chronic inhalation. Additional model validation is needed for nanoparticles of varying characteristics, as well as extension of these models to include particle translocation to organs beyond the lungs. Such analyses would provide improved prediction of nanoparticle dose for risk assessment.

  14. A mathematical model of particle retention in the air-spaces of human lungs.

    PubMed Central

    Gerrity, T R; Garrard, C S; Yeates, D B

    1983-01-01

    Knowledge of the total and regional lung retention of particles inhaled continuously by man over long periods can be useful in understanding the potential role of inhaled particles in the pathogenesis of lung diseases. Owing to practical and ethical considerations, however, little or no experimental information exists. A mathematical model of particle retention simulating environmental and occupational exposures has therefore been developed that takes into account particle deposition, tracheobronchial clearance, and two phases of alveolar clearance in the Weibel A anatomical lung model. The derived equations of retention kinetics predict retention of particles as a function of exposure time. For a continuous exposure (simulating environmental conditions) to 4 microns particles, the model predicts that retained particles approach an equilibrium between deposited and cleared particles with the 95% level being reached in 293 days. For an intermittent exposure (simulating occupational conditions) equilibrium is approached in five years. The whole lung burden of particles is predicted to be 9% of the total mass that entered the lung after a one-year environmental exposure and 1.5% after a 25-year occupational exposure. The equilibrium surface concentration and integrated dose of particles per airway generation predict enhanced risk to the pathogenic effects of inhaled particles in the large airways and respiratory bronchioles. PMID:6830707

  15. The need for a new animal model for chronic rejection after lung transplantation.

    PubMed

    De Vleeschauwer, S; Vanaudenaerde, B; Vos, R; Meers, C; Wauters, S; Dupont, L; Van Raemdonck, D; Verleden, G

    2011-11-01

    The single most important cause of late mortality after lung transplantation is obliterative bronchiolitis (OB), clinically characterized by a decrease in lung function and morphologically by characteristic changes. Recently, new insights into its pathogenesis have been acquired: risk factors have been identified and the use of azithromycin showed a dichotomy with at least 2 different phenotypes of bronchiolitis obliterans syndrome (BOS). It is clear that a good animal model is indispensable to further dissect and unravel the pathogenesis of BOS. Many animal models have been developed to study BOS but, so far, none of these models truly mimics the human situation. Looking at the definition of BOS, a good animal model implies histological OB lesions, possibility to measure lung function, and airway inflammation. This review sought to discuss, including pros and cons, all potential animal models that have been developed to study OB/BOS. It has become clear that a new animal model is needed; recent developments using an orthotopic mouse lung transplantation model may offer the answer because it mimics the human situation. The genetic variants among this species may open new perspectives for research into the pathogenesis of OB/BOS. PMID:22099823

  16. A GPU-based framework for modeling real-time 3D lung tumor conformal dosimetry with subject-specific lung tumor motion

    NASA Astrophysics Data System (ADS)

    Min, Yugang; Santhanam, Anand; Neelakkantan, Harini; Ruddy, Bari H.; Meeks, Sanford L.; Kupelian, Patrick A.

    2010-09-01

    In this paper, we present a graphics processing unit (GPU)-based simulation framework to calculate the delivered dose to a 3D moving lung tumor and its surrounding normal tissues, which are undergoing subject-specific lung deformations. The GPU-based simulation framework models the motion of the 3D volumetric lung tumor and its surrounding tissues, simulates the dose delivery using the dose extracted from a treatment plan using Pinnacle Treatment Planning System, Phillips, for one of the 3DCTs of the 4DCT and predicts the amount and location of radiation doses deposited inside the lung. The 4DCT lung datasets were registered with each other using a modified optical flow algorithm. The motion of the tumor and the motion of the surrounding tissues were simulated by measuring the changes in lung volume during the radiotherapy treatment using spirometry. The real-time dose delivered to the tumor for each beam is generated by summing the dose delivered to the target volume at each increase in lung volume during the beam delivery time period. The simulation results showed the real-time capability of the framework at 20 discrete tumor motion steps per breath, which is higher than the number of 4DCT steps (approximately 12) reconstructed during multiple breathing cycles.

  17. A computer simulation model of the cost-effectiveness of routine Staphylococcus aureus screening and decolonization among lung and heart-lung transplant recipients.

    PubMed

    Clancy, C J; Bartsch, S M; Nguyen, M H; Stuckey, D R; Shields, R K; Lee, B Y

    2014-06-01

    Our objective was to model the cost-effectiveness and economic value of routine peri-operative Staphylococcus aureus screening and decolonization of lung and heart-lung transplant recipients from hospital and third-party payer perspectives. We used clinical data from 596 lung and heart-lung transplant recipients to develop a model in TreeAge Pro 2009 (Williamsport, MA, USA). Sensitivity analyses varied S. aureus colonization rate (5-15 %), probability of infection if colonized (10-30 %), and decolonization efficacy (25-90 %). Data were collected from the Cardiothoracic Transplant Program at the University of Pittsburgh Medical Center. Consecutive lung and heart-lung transplant recipients from January 2006 to December 2010 were enrolled retrospectively. Baseline rates of S. aureus colonization, infection and decolonization efficacy were 9.6 %, 36.7 %, and 31.9 %, respectively. Screening and decolonization was economically dominant for all scenarios tested, providing more cost savings and health benefits than no screening. Savings per case averted (2012 $US) ranged from $73,567 to $133,157 (hospital perspective) and $10,748 to $16,723 (third party payer perspective), varying with the probability of colonization, infection, and decolonization efficacy. Using our clinical data, screening and decolonization led to cost savings per case averted of $240,602 (hospital perspective) and averted 6.7 S. aureus infections (4.3 MRSA and 2.4 MSSA); 89 patients needed to be screened to prevent one S. aureus infection. Our data support routine S. aureus screening and decolonization of lung and heart-lung transplant patients. The economic value of screening and decolonization was greater than in previous models of other surgical populations. PMID:24500598

  18. Targeting the urokinase plasminogen activator receptor enhances gene transfer to human airway epithelia

    PubMed Central

    Drapkin, Paola T.; O’Riordan, Catherine R.; Yi, Su Min; Chiorini, John A.; Cardella, Jonathan; Zabner, Joseph; Welsh, Michael J.

    2000-01-01

    Developing gene therapy for cystic fibrosis has been hindered by limited binding and endocytosis of vectors by human airway epithelia. Here we show that the apical membrane of airway epithelia express the urokinase plasminogen activator receptor (uPAR). Urokinase plasminogen activator (uPA), or a 7-residue peptide derived from this protein (u7-peptide), bound the receptor and stimulated apical endocytosis. Both ligands enhanced gene transfer by nonspecifically bound adenovirus and adeno-associated virus vectors and by a modified adenovirus vector that had been coupled to the u7-peptide. These data provide the first evidence that targeting an apical receptor can circumvent the two most important barriers to gene transfer in airway epithelia. Thus, the uPA/uPAR system may offer significant advantages for delivering genes and other pharmaceuticals to airway epithelia. PMID:10712430

  19. Targeting the urokinase plasminogen activator receptor enhances gene transfer to human airway epithelia.

    PubMed

    Drapkin, P T; O'Riordan, C R; Yi, S M; Chiorini, J A; Cardella, J; Zabner, J; Welsh, M J

    2000-03-01

    Developing gene therapy for cystic fibrosis has been hindered by limited binding and endocytosis of vectors by human airway epithelia. Here we show that the apical membrane of airway epithelia express the urokinase plasminogen activator receptor (uPAR). Urokinase plasminogen activator (uPA), or a 7-residue peptide derived from this protein (u7-peptide), bound the receptor and stimulated apical endocytosis. Both ligands enhanced gene transfer by nonspecifically bound adenovirus and adeno-associated virus vectors and by a modified adenovirus vector that had been coupled to the u7-peptide. These data provide the first evidence that targeting an apical receptor can circumvent the two most important barriers to gene transfer in airway epithelia. Thus, the uPA/uPAR system may offer significant advantages for delivering genes and other pharmaceuticals to airway epithelia. PMID:10712430

  20. A Novel Telomerase Activator Suppresses Lung Damage in a Murine Model of Idiopathic Pulmonary Fibrosis

    PubMed Central

    Le Saux, Claude Jourdan; Davy, Philip; Brampton, Christopher; Ahuja, Seema S.; Fauce, Steven; Shivshankar, Pooja; Nguyen, Hieu; Ramaseshan, Mahesh; Tressler, Robert; Pirot, Zhu; Harley, Calvin B.; Allsopp, Richard

    2013-01-01

    The emergence of diseases associated with telomere dysfunction, including AIDS, aplastic anemia and pulmonary fibrosis, has bolstered interest in telomerase activators. We report identification of a new small molecule activator, GRN510, with activity ex vivo and in vivo. Using a novel mouse model, we tested the potential of GRN510 to limit fibrosis induced by bleomycin in mTERT heterozygous mice. Treatment with GRN510 at 10 mg/kg/day activated telomerase 2–4 fold both in hematopoietic progenitors ex vivo and in bone marrow and lung tissue in vivo, respectively. Telomerase activation was countered by co-treatment with Imetelstat (GRN163L), a potent telomerase inhibitor. In this model of bleomycin-induced fibrosis, treatment with GRN510 suppressed the development of fibrosis and accumulation of senescent cells in the lung via a mechanism dependent upon telomerase activation. Treatment of small airway epithelial cells (SAEC) or lung fibroblasts ex vivo with GRN510 revealed telomerase activating and replicative lifespan promoting effects only in the SAEC, suggesting that the mechanism accounting for the protective effects of GRN510 against induced lung fibrosis involves specific types of lung cells. Together, these results support the use of small molecule activators of telomerase in therapies to treat idiopathic pulmonary fibrosis. PMID:23516479

  1. A novel telomerase activator suppresses lung damage in a murine model of idiopathic pulmonary fibrosis.

    PubMed

    Le Saux, Claude Jourdan; Davy, Philip; Brampton, Christopher; Ahuja, Seema S; Fauce, Steven; Shivshankar, Pooja; Nguyen, Hieu; Ramaseshan, Mahesh; Tressler, Robert; Pirot, Zhu; Harley, Calvin B; Allsopp, Richard

    2013-01-01

    The emergence of diseases associated with telomere dysfunction, including AIDS, aplastic anemia and pulmonary fibrosis, has bolstered interest in telomerase activators. We report identification of a new small molecule activator, GRN510, with activity ex vivo and in vivo. Using a novel mouse model, we tested the potential of GRN510 to limit fibrosis induced by bleomycin in mTERT heterozygous mice. Treatment with GRN510 at 10 mg/kg/day activated telomerase 2-4 fold both in hematopoietic progenitors ex vivo and in bone marrow and lung tissue in vivo, respectively. Telomerase activation was countered by co-treatment with Imetelstat (GRN163L), a potent telomerase inhibitor. In this model of bleomycin-induced fibrosis, treatment with GRN510 suppressed the development of fibrosis and accumulation of senescent cells in the lung via a mechanism dependent upon telomerase activation. Treatment of small airway epithelial cells (SAEC) or lung fibroblasts ex vivo with GRN510 revealed telomerase activating and replicative lifespan promoting effects only in the SAEC, suggesting that the mechanism accounting for the protective effects of GRN510 against induced lung fibrosis involves specific types of lung cells. Together, these results support the use of small molecule activators of telomerase in therapies to treat idiopathic pulmonary fibrosis. PMID:23516479

  2. Effect of air pollution on lung cancer: A poisson regression model based on vital statistics

    SciTech Connect

    Tango, Toshiro

    1994-11-01

    This article describes a Poisson regression model for time trends of mortality to detect the long-term effects of common levels of air pollution on lung cancer, in which the adjustment for cigarette smoking is not always necessary. The main hypothesis to be tested in the model is that if the long-term and common-level air pollution had an effect on lung cancer, the death rate from lung cancer could be expected to increase gradually at a higher rate in the region with relatively high levels of air pollution than in the region with low levels, and that this trend would not be expected for other control diseases in which cigarette smoking is a risk factor. Using this approach, we analyzed the trend of mortality in females aged 40 to 79, from lung cancer and two control diseases, ischemic heart disease and cerebrovascular disease, based on vital statistics in 23 wards of the Tokyo metropolitan area for 1972 to 1988. Ward-specific mean levels per day of SO{sub 2} and NO{sub 2} from 1974 through 1976 estimated by Makino (1978) were used as the ward-specific exposure measure of air pollution. No data on tobacco consumption in each ward is available. Our analysis supported the existence of long-term effects of air pollution on lung cancer. 14 refs., 5 figs., 2 tabs.

  3. Effects of Hydrostatic Pressure on Carcinogenic Properties of Epithelia

    PubMed Central

    Tokuda, Shinsaku; Kim, Young Hak; Matsumoto, Hisako; Muro, Shigeo; Hirai, Toyohiro; Mishima, Michiaki; Furuse, Mikio

    2015-01-01

    The relationship between chronic inflammation and cancer is well known. The inflammation increases the permeability of blood vessels and consequently elevates pressure in the interstitial tissues. However, there have been only a few reports on the effects of hydrostatic pressure on cultured cells, and the relationship between elevated hydrostatic pressure and cell properties related to malignant tumors is less well understood. Therefore, we investigated the effects of hydrostatic pressure on the cultured epithelial cells seeded on permeable filters. Surprisingly, hydrostatic pressure from basal to apical side induced epithelial stratification in Madin-Darby canine kidney (MDCK) I and Caco-2 cells, and cavities with microvilli and tight junctions around their surfaces were formed within the multi-layered epithelia. The hydrostatic pressure gradient also promoted cell proliferation, suppressed cell apoptosis, and increased transepithelial ion permeability. The inhibition of protein kinase A (PKA) promoted epithelial stratification by the hydrostatic pressure whereas the activation of PKA led to suppressed epithelial stratification. These results indicate the role of the hydrostatic pressure gradient in the regulation of various epithelial cell functions. The findings in this study may provide clues for the development of a novel strategy for the treatment of the carcinoma. PMID:26716691

  4. Crossroads of integrins and cadherins in epithelia and stroma remodeling.

    PubMed

    Epifano, Carolina; Perez-Moreno, Mirna

    2012-01-01

    Adhesion events mediated by cadherin and integrin adhesion receptors have fundamental roles in the maintenance of the physiological balance of epithelial tissues, and it is well established that perturbations in their normal functional activity and/or changes in their expression are associated with tumorigenesis. Over the last decades, increasing evidence of a dynamic collaborative interaction between these complexes through their shared interactions with cytoskeletal proteins and common signaling pathways has emerged not only as an important regulator of several aspects of epithelial cell behavior, but also as a coordinated adhesion module that senses and transmits signals from and to the epithelia surrounding microenvironment. The tight regulation of their crosstalk is particularly important during epithelial remodeling events that normally take place during morphogenesis and tissue repair, and when defective it leads to cell transformation and aggravated responses of the tumor microenvironment that contribute to tumorigenesis. In this review we highlight some of the interactions that regulate their crosstalk and how this could be implicated in regulating signals across epithelial tissues to sustain homeostasis. PMID:22568988

  5. Fatty Acids Inhibit Apical Membrane Chloride Channels in Airway Epithelia

    NASA Astrophysics Data System (ADS)

    Anderson, Matthew P.; Welsh, Michael J.

    1990-09-01

    Apical membrane Cl^- channels control the rate of transepithelial Cl^- secretion in airway epithelia. cAMP-dependent protein kinase and protein kinase C regulate Cl^- channels by phosphorylation; in cystic fibrosis cells, phosphorylation-dependent activation of Cl^- channels is defective. Another important signaling system involves arachidonic acid, which is released from cell membranes during receptor-mediated stimulation. Here we report that arachidonic acid reversibly inhibited apical membrane Cl^- channels in cell-free patches of membrane. Arachidonic acid itself inhibited the channel and not a cyclooxygenase or lipoxygenase metabolite because (i) inhibitors of these enzymes did not block the response, (ii) fatty acids that are not substrates for the enzymes had the same effect as arachidonic acid, and (iii) metabolites of arachidonic acid did not inhibit the channel. Inhibition occurred only when fatty acids were added to the cytosolic surface of the membrane patch. Unsaturated fatty acids were more potent than saturated fatty acids. Arachidonic acid inhibited Cl^- channels from both normal and cystic fibrosis cells. These results suggest that fatty acids directly inhibit apical membrane Cl^- channels in airway epithelial cells.

  6. Computational fluid dynamics simulations of particle deposition in large-scale, multigenerational lung models.

    PubMed

    Walters, D Keith; Luke, William H

    2011-01-01

    Computational fluid dynamics (CFD) has emerged as a useful tool for the prediction of airflow and particle transport within the human lung airway. Several published studies have demonstrated the use of Eulerian finite-volume CFD simulations coupled with Lagrangian particle tracking methods to determine local and regional particle deposition rates in small subsections of the bronchopulmonary tree. However, the simulation of particle transport and deposition in large-scale models encompassing more than a few generations is less common, due in part to the sheer size and complexity of the human lung airway. Highly resolved, fully coupled flowfield solution and particle tracking in the entire lung, for example, is currently an intractable problem and will remain so for the foreseeable future. This paper adopts a previously reported methodology for simulating large-scale regions of the lung airway (Walters, D. K., and Luke, W. H., 2010, "A Method for Three-Dimensional Navier-Stokes Simulations of Large-Scale Regions of the Human Lung Airway," ASME J. Fluids Eng., 132(5), p. 051101), which was shown to produce results similar to fully resolved geometries using approximate, reduced geometry models. The methodology is extended here to particle transport and deposition simulations. Lagrangian particle tracking simulations are performed in combination with Eulerian simulations of the airflow in an idealized representation of the human lung airway tree. Results using the reduced models are compared with those using the fully resolved models for an eight-generation region of the conducting zone. The agreement between fully resolved and reduced geometry simulations indicates that the new method can provide an accurate alternative for large-scale CFD simulations while potentially reducing the computational cost of these simulations by several orders of magnitude. PMID:21186893

  7. Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia

    PubMed Central

    Bragulla, Hermann H; Homberger, Dominique G

    2009-01-01

    Historically, the term ‘keratin’ stood for all of the proteins extracted from skin modifications, such as horns, claws and hooves. Subsequently, it was realized that this keratin is actually a mixture of keratins, keratin filament-associated proteins and other proteins, such as enzymes. Keratins were then defined as certain filament-forming proteins with specific physicochemical properties and extracted from the cornified layer of the epidermis, whereas those filament-forming proteins that were extracted from the living layers of the epidermis were grouped as ‘prekeratins’ or ‘cytokeratins’. Currently, the term ‘keratin’ covers all intermediate filament-forming proteins with specific physicochemical properties and produced in any vertebrate epithelia. Similarly, the nomenclature of epithelia as cornified, keratinized or non-keratinized is based historically on the notion that only the epidermis of skin modifications such as horns, claws and hooves is cornified, that the non-modified epidermis is a keratinized stratified epithelium, and that all other stratified and non-stratified epithelia are non-keratinized epithelia. At this point in time, the concepts of keratins and of keratinized or cornified epithelia need clarification and revision concerning the structure and function of keratin and keratin filaments in various epithelia of different species, as well as of keratin genes and their modifications, in view of recent research, such as the sequencing of keratin proteins and their genes, cell culture, transfection of epithelial cells, immunohistochemistry and immunoblotting. Recently, new functions of keratins and keratin filaments in cell signaling and intracellular vesicle transport have been discovered. It is currently understood that all stratified epithelia are keratinized and that some of these keratinized stratified epithelia cornify by forming a Stratum corneum. The processes of keratinization and cornification in skin modifications are

  8. Animal Models, Learning Lessons to Prevent and Treat Neonatal Chronic Lung Disease

    PubMed Central

    Jobe, Alan H.

    2015-01-01

    Bronchopulmonary dysplasia (BPD) is a unique injury syndrome caused by prolonged injury and repair imposed on an immature and developing lung. The decreased septation and decreased microvascular development phenotype of BPD can be reproduced in newborn rodents with increased chronic oxygen exposure and in premature primates and sheep with oxygen and/or mechanical ventilation. The inflammation caused by oxidants, inflammatory agonists, and/or stretch injury from mechanical ventilation seems to promote the anatomic abnormalities. Multiple interventions targeted to specific inflammatory cells or pathways or targeted to decreasing ventilation-mediated injury can substantially prevent the anatomic changes associated with BPD in term rodents and in preterm sheep or primate models. Most of the anti-inflammatory therapies with benefit in animal models have not been tested clinically. None of the interventions that have been tested clinically are as effective as anticipated from the animal models. These inconsistencies in responses likely are explained by the antenatal differences in lung exposures of the developing animals relative to very preterm humans. The animals generally have normal lungs while the lungs of preterm infants are exposed variably to intrauterine inflammation, growth abnormalities, antenatal corticosteroids, and poorly understood effects from the causes of preterm delivery. The animal models have been essential for the definition of the mediators that can cause a BPD phenotype. These models will be necessary to develop and test future-targeted interventions to prevent and treat BPD. PMID:26301222

  9. Tracking boundary movement and exterior shape modelling in lung EIT imaging.

    PubMed

    Biguri, A; Grychtol, B; Adler, A; Soleimani, M

    2015-06-01

    Electrical impedance tomography (EIT) has shown significant promise for lung imaging. One key challenge for EIT in this application is the movement of electrodes during breathing, which introduces artefacts in reconstructed images. Various approaches have been proposed to compensate for electrode movement, but no comparison of these approaches is available. This paper analyses boundary model mismatch and electrode movement in lung EIT. The aim is to evaluate the extent to which various algorithms tolerate movement, and to determine if a patient specific model is required for EIT lung imaging. Movement data are simulated from a CT-based model, and image analysis is performed using quantitative figures of merit. The electrode movement is modelled based on expected values of chest movement and an extended Jacobian method is proposed to make use of exterior boundary tracking. Results show that a dynamical boundary tracking is the most robust method against any movement, but is computationally more expensive. Simultaneous electrode movement and conductivity reconstruction algorithms show increased robustness compared to only conductivity reconstruction. The results of this comparative study can help develop a better understanding of the impact of shape model mismatch and electrode movement in lung EIT. PMID:26007150

  10. Computational Multiscale Toxicodynamic Modeling of Silver and Carbon Nanoparticle Effects on Mouse Lung Function

    PubMed Central

    Mukherjee, Dwaipayan; Botelho, Danielle; Gow, Andrew J.; Zhang, Junfeng; Georgopoulos, Panos G.

    2013-01-01

    A computational, multiscale toxicodynamic model has been developed to quantify and predict pulmonary effects due to uptake of engineered nanomaterials (ENMs) in mice. The model consists of a collection of coupled toxicodynamic modules, that were independently developed and tested using information obtained from the literature. The modules were developed to describe the dynamics of tissue with explicit focus on the cells and the surfactant chemicals that regulate the process of breathing, as well as the response of the pulmonary system to xenobiotics. Alveolar type I and type II cells, and alveolar macrophages were included in the model, along with surfactant phospholipids and surfactant proteins, to account for processes occurring at multiple biological scales, coupling cellular and surfactant dynamics affected by nanoparticle exposure, and linking the effects to tissue-level lung function changes. Nanoparticle properties such as size, surface chemistry, and zeta potential were explicitly considered in modeling the interactions of these particles with biological media. The model predictions were compared with in vivo lung function response measurements in mice and analysis of mice lung lavage fluid following exposures to silver and carbon nanoparticles. The predictions were found to follow the trends of observed changes in mouse surfactant composition over 7 days post dosing, and are in good agreement with the observed changes in mouse lung function over the same period of time. PMID:24312506

  11. Lung-On-A-Chip Technologies for Disease Modeling and Drug Development

    PubMed Central

    Konar, Dipasri; Devarasetty, Mahesh; Yildiz, Didem V.; Atala, Anthony; Murphy, Sean V.

    2016-01-01

    Animal and two-dimensional cell culture models have had a profound impact on not only lung research but also medical research at large, despite inherent flaws and differences when compared with in vivo and clinical observations. Three-dimensional (3D) tissue models are a natural progression and extension of existing techniques that seek to plug the gaps and mitigate the drawbacks of two-dimensional and animal technologies. In this review, we describe the transition of historic models to contemporary 3D cell and organoid models, the varieties of current 3D cell and tissue culture modalities, the common methods for imaging these models, and finally, the applications of these models and imaging techniques to lung research. PMID:27127414

  12. Cigarette smoke and calcium conspire to impair CFTR function in airway epithelia.

    PubMed

    Braun, Andrew P

    2014-01-01

    To maintain health and function in response to inhaled environmental irritants and toxins, the lungs and airways depend upon an innate defense system that involves the secretion of mucus (i.e., mucin, salts, and water) by airway epithelium onto the apical surface to trap foreign particles. Airway mucus is then transported in an oral direction via ciliary beating and coughing, which helps to keep the airways clear. CFTR (cystic fibrosis transmembrane conductance regulator) is a cAMP-regulated Cl(-) channel in the apical membrane of epithelium that contributes to salt and water secretion onto the luminal surface of airways, thereby ensuring that secreted mucus is sufficiently hydrated for movement along the epithelial surface. Dehydration of airway mucus, as occurs in cystic fibrosis, results in a more viscous, less mobile secretion that compromises the lung’s innate defense system by facilitating a build-up of foreign particles and bacterial growth. Related to this situation is chronic obstructive pulmonary disease (COPD), which is a leading cause of death globally. A major cause of COPD is cigarette smoking, which has been reported to decrease the cellular levels of CFTR in airway epithelia. In their recent article, Rasmussen and coworkers now report that exposure to cigarette smoke elevates cytosolic free Ca(2+) in airway epithelium, leading to decreased surface localization and cellular expression of CFTR and reduced levels of secreted airway surface liquid. Blocking this increase in cytosolic Ca(2+) largely prevented CFTR loss in airway epithelium and surprisingly, cellular lysosomes appear to be a major source for smoke-induced Ca(2+) elevation. PMID:24755862

  13. Development of ferret as a human lung cancer model by injecting4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of new animal lung cancer models that are relevant to human lung carcinogenesis is important for lung cancer research. Previously we have shown the induction of lung tumor in ferrets (Mustela putorius furo) exposed to both tobacco smoke and a tobacco carcinogen (4-(N-methyl-N-nitrosamino...

  14. Neutrophils and their Fcγ receptors are essential in a mouse model of transfusion-related acute lung injury

    PubMed Central

    Looney, Mark R.; Su, Xiao; Van Ziffle, Jessica A.; Lowell, Clifford A.; Matthay, Michael A.

    2006-01-01

    Transfusion-related acute lung injury (TRALI) is the most common cause of transfusion-related mortality. To explore the pathogenesis of TRALI, we developed an in vivo mouse model based on the passive transfusion of an MHC class I (MHC I) mAb (H2Kd) to mice with the cognate antigen. Transfusion of the MHC I mAb to BALB/c mice produced acute lung injury with increased excess lung water, increased lung vascular and lung epithelial permeability to protein, and decreased alveolar fluid clearance. There was 50% mortality at a 2-hour time point after Ab administration. Pulmonary histology and immunohistochemistry revealed prominent neutrophil sequestration in the lung microvasculature that occurred concomitantly with acute peripheral blood neutropenia, all within 2 hours of administration of the mAb. Depletion of neutrophils by injection of anti-granulocyte mAb Gr-1 protected mice from lung injury following MHC I mAb challenge. FcRγ–/– mice were resistant to MHC I mAb–induced lung injury, while adoptive transfer of wild-type neutrophils into the FcRγ–/– animals restored lung injury following MHC I mAb challenge. In conclusion, in a clinically relevant in vivo mouse model of TRALI using an MHC I mAb, the mechanism of lung injury was dependent on neutrophils and their Fcγ receptors. PMID:16710475

  15. Optimizing principal component models for representing interfraction variation in lung cancer radiotherapy

    SciTech Connect

    Badawi, Ahmed M.; Weiss, Elisabeth; Sleeman, William C. IV; Yan Chenyu; Hugo, Geoffrey D.

    2010-09-15

    Purpose: To optimize modeling of interfractional anatomical variation during active breath-hold radiotherapy in lung cancer using principal component analysis (PCA). Methods: In 12 patients analyzed, weekly CT sessions consisting of three repeat intrafraction scans were acquired with active breathing control at the end of normal inspiration. The gross tumor volume (GTV) and lungs were delineated and reviewed on the first week image by physicians and propagated to all other images using deformable image registration. PCA was used to model the target and lung variability during treatment. Four PCA models were generated for each specific patient: (1) Individual models for the GTV and each lung from one image per week (week to week, W2W); (2) a W2W composite model of all structures; (3) individual models using all images (weekly plus repeat intrafraction images, allscans); and (4) composite model with all images. Models were reconstructed retrospectively (using all available images acquired) and prospectively (using only data acquired up to a time point during treatment). Dominant modes representing at least 95% of the total variability were used to reconstruct the observed anatomy. Residual reconstruction error between the model-reconstructed and observed anatomy was calculated to compare the accuracy of the models. Results: An average of 3.4 and 4.9 modes was required for the allscans models, for the GTV and composite models, respectively. The W2W model required one less mode in 40% of the patients. For the retrospective composite W2W model, the average reconstruction error was 0.7{+-}0.2 mm, which increased to 1.1{+-}0.5 mm when the allscans model was used. Individual and composite models did not have significantly different errors (p=0.15, paired t-test). The average reconstruction error for the prospective models of the GTV stabilized after four measurements at 1.2{+-}0.5 mm and for the composite model after five measurements at 0.8{+-}0.4 mm. Conclusions

  16. Redistribution of pulmonary blood flow impacts thermodilution-based extravascular lung water measurements in a model of acute lung injury

    PubMed Central

    Easley, R. Blaine; Mulreany, Daniel G.; Lancaster, Christopher T.; Custer, Jason W.; Fernandez-Bustamante, Ana; Colantuoni, Elizabeth; Simon, Brett A.

    2009-01-01

    Background Studies using transthoracic thermodilution have demonstrated increased extravascular lung water (EVLW) measurements attributed to progression of edema and flooding during sepsis and acute lung injury. We hypothesize that redistribution of pulmonary blood flow can cause increased apparent EVLW secondary to increased perfusion of thermally silent tissue, not increased lung edema. Methods Anesthetized, mechanically ventilated canines were instrumented with PiCCO® (Pulsion Medical, Munich, Germany) catheters and underwent lung injury by repetitive saline lavage. Hemodynamic and respiratory physiologic data were recorded. After stabilized lung injury, endotoxin was administered to inactivate hypoxic pulmonary vasoconstriction. Computerized tomographic imaging was performed to quantify in vivo lung volume, total tissue (fluid) and air content, and regional distribution of blood flow. Results Lavage injury caused an increase in airway pressures and decreased arterial oxygen content with minimal hemodynamic effects. EVLW and shunt fraction increased after injury and then markedly following endotoxin administration. Computerized tomographic measurements quantified an endotoxin-induced increase in pulmonary blood flow to poorly aerated regions with no change in total lung tissue volume. Conclusions The abrupt increase in EVLW and shunt fraction after endotoxin administration is consistent with inactivation of hypoxic pulmonary vasoconstriction and increased perfusion to already flooded lung regions that were previously thermally silent. Computerized tomographic studies further demonstrate in vivo alterations in regional blood flow (but not lung water) and account for these alterations in shunt fraction and EVLW. PMID:19809280

  17. Establishment of a Rat Adjuvant Arthritis-Interstitial Lung Disease Model

    PubMed Central

    Song, Liu-nan; Kong, Xiao-dan; Wang, Hong-jiang; Zhan, Li-bin

    2016-01-01

    Introduction. Development of an animal model of rheumatoid arthritis-interstitial lung disease (RA-ILD) and improved knowledge of the pathogenesis of RA-ILD may facilitate earlier diagnosis and the development of more effective targeted therapies. Methods. Adult male Wistar rats were studied in an adjuvant arthritis (AA) model induced by the injection of Freund's complete adjuvant (FCA). Rats were sacrificed on days 7, 14, 21, and 28 after FCA injection. Lung tissue was obtained for histopathological examination and evaluation of Caveolin-1 (Cav-1) and transforming growth factor-β (TGF-β1) protein expression levels. Results. Pulmonary inflammation was evident in lung tissue from day 21 after FCA injection. Inflammation and mild fibrosis were observed in lung tissue on day 28 after FCA injection. Cav-1 protein expression was significantly decreased from day 7 through day 28 and TGF-β1 protein expression was significantly increased on day 28 after FCA injection compared to control (P < 0.05). Conclusion. We established an AA rat model that exhibited the extra-articular complication of RA-ILD. We identified Cav-1 and TGF-β1 as protein biomarkers of RA-ILD in this model and propose their signaling pathway as a possible target for therapeutic intervention. PMID:26881215

  18. Quantifying lung morphology with respiratory-gated micro-CT in a murine model of emphysema

    NASA Astrophysics Data System (ADS)

    Ford, N. L.; Martin, E. L.; Lewis, J. F.; Veldhuizen, R. A. W.; Holdsworth, D. W.; Drangova, M.

    2009-04-01

    Non-invasive micro-CT imaging techniques have been developed to investigate lung structure in free-breathing rodents. In this study, we investigate the utility of retrospectively respiratory-gated micro-CT imaging in an emphysema model to determine if anatomical changes could be observed in the image-derived quantitative analysis at two respiratory phases. The emphysema model chosen was a well-characterized, genetically altered model (TIMP-3 knockout mice) that exhibits a homogeneous phenotype. Micro-CT scans of the free-breathing, anaesthetized mice were obtained in 50 s and retrospectively respiratory sorted and reconstructed, providing 3D images representing peak inspiration and end expiration with 0.15 mm isotropic voxel spacing. Anatomical measurements included the volume and CT density of the lungs and the volume of the major airways, along with the diameters of the trachea, left bronchus and right bronchus. From these measurements, functional parameters such as functional residual capacity and tidal volume were calculated. Significant differences between the wild-type and TIMP-3 knockout groups were observed for measurements of CT density over the entire lung, indicating increased air content in the lungs of TIMP-3 knockout mice. These results demonstrate retrospective respiratory-gated micro-CT, providing images at multiple respiratory phases that can be analyzed quantitatively to investigate anatomical changes in murine models of emphysema.

  19. Nanoparticle mass transfer from lung airways to systemic regions--Part II: Multi-compartmental modeling.

    PubMed

    Kolanjiyil, Arun V; Kleinstreuer, Clement

    2013-12-01

    This is the second article of a two-part paper, combining high-resolution computer simulation results of inhaled nanoparticle deposition in a human airway model (Kolanjiyil and Kleinstreuer, 2013, "Nanoparticle Mass Transfer From Lung Airways to Systemic Regions--Part I: Whole-Lung Aerosol Dynamics," ASME J. Biomech. Eng., 135(12), p. 121003) with a new multicompartmental model for insoluble nanoparticle barrier mass transfer into systemic regions. Specifically, it allows for the prediction of temporal nanoparticle accumulation in the blood and lymphatic systems and in organs. The multicompartmental model parameters were determined from experimental retention and clearance data in rat lungs and then the validated model was applied to humans based on pharmacokinetic cross-species extrapolation. This hybrid simulator is a computationally efficient tool to predict the nanoparticle kinetics in the human body. The study provides critical insight into nanomaterial deposition and distribution from the lungs to systemic regions. The quantitative results are useful in diverse fields such as toxicology for exposure-risk analysis of ubiquitous nanomaterial and pharmacology for nanodrug development and targeting. PMID:24008585

  20. The Audible Human Project: Modeling Sound Transmission in the Lungs and Torso

    NASA Astrophysics Data System (ADS)

    Dai, Zoujun

    Auscultation has been used qualitatively by physicians for hundreds of years to aid in the monitoring and diagnosis of pulmonary diseases. Alterations in the structure and function of the pulmonary system that occur in disease or injury often give rise to measurable changes in lung sound production and transmission. Numerous acoustic measurements have revealed the differences of breath sounds and transmitted sounds in the lung under normal and pathological conditions. Compared to the extensive cataloging of lung sound measurements, the mechanism of sound transmission in the pulmonary system and how it changes with alterations of lung structural and material properties has received less attention. A better understanding of sound transmission and how it is altered by injury and disease might improve interpretation of lung sound measurements, including new lung imaging modalities that are based on an array measurement of the acoustic field on the torso surface via contact sensors or are based on a 3-dimensional measurement of the acoustic field throughout the lungs and torso using magnetic resonance elastography. A long-term goal of the Audible Human Project (AHP ) is to develop a computational acoustic model that would accurately simulate generation, transmission and noninvasive measurement of sound and vibration within the pulmonary system and torso caused by both internal (e.g. respiratory function) and external (e.g. palpation) sources. The goals of this dissertation research, fitting within the scope of the AHP, are to develop specific improved theoretical understandings, computational algorithms and experimental methods aimed at transmission and measurement. The research objectives undertaken in this dissertation are as follows. (1) Improve theoretical modeling and experimental identification of viscoelasticity in soft biological tissues. (2) Develop a poroviscoelastic model for lung tissue vibroacoustics. (3) Improve lung airway acoustics modeling and its

  1. Novel electrospun gelatin/oxycellulose nanofibers as a suitable platform for lung disease modeling.

    PubMed

    Švachová, Veronika; Vojtová, Lucy; Pavliňák, David; Vojtek, Libor; Sedláková, Veronika; Hyršl, Pavel; Alberti, Milan; Jaroš, Josef; Hampl, Aleš; Jančář, Josef

    2016-10-01

    Novel hydrolytically stable gelatin nanofibers modified with sodium or calcium salt of oxycellulose were prepared by electrospinning method. The unique inhibitory effect of these nanofibers against Escherichia coli bacteria was examined by luminometric method. Biocompatibility of these gelatin/oxycellulose nanofibers with eukaryotic cells was tested using human lung adenocarcinoma cell line NCI-H441. Cells firmly adhered to nanofiber surface, as determined by scanning electron microscopy, and no signs of cell dying were detected by fluorescent live/dead assay. We propose that the newly developed gelatin/oxycellulose nanofibers could be used as promising scaffold for lung disease modeling and anti-cancer drug testing. PMID:27287147

  2. The Rabbit as a Model for Studying Lung Disease and Stem Cell Therapy

    PubMed Central

    Kamaruzaman, Nurfatin Asyikhin; Kamaldin, Nurulain ‘Atikah; Latahir, Ahmad Zaeri; Yahaya, Badrul Hisham

    2013-01-01

    No single animal model can reproduce all of the human features of both acute and chronic lung diseases. However, the rabbit is a reliable model and clinically relevant facsimile of human disease. The similarities between rabbits and humans in terms of airway anatomy and responses to inflammatory mediators highlight the value of this species in the investigation of lung disease pathophysiology and in the development of therapeutic agents. The inflammatory responses shown by the rabbit model, especially in the case of asthma, are comparable with those that occur in humans. The allergic rabbit model has been used extensively in drug screening tests, and this model and humans appear to be sensitive to similar drugs. In addition, recent studies have shown that the rabbit serves as a good platform for cell delivery for the purpose of stem-cell-based therapy. PMID:23653896

  3. Comparison of two lung clearance models based on the dissolution rates of oxidized depleted uranium

    SciTech Connect

    Crist, K.C.

    1984-10-01

    An in-vitro dissolution study was conducted on two respirable oxidized depleted uranium samples. The dissolution rates generated from this study were then utilized in the International Commission on Radiological Protection Task Group lung clearance model and a lung clearance model proposed by Cuddihy. Predictions from both models based on the dissolution rates of the amount of oxidized depleted uranium that would be cleared to blood from the pulmonary region following an inhalation exposure were compared. It was found that the predictions made by both models differed considerably. The difference between the predictions was attributed to the differences in the way each model perceives the clearance from the pulmonary region. 33 references, 11 figures, 9 tables.

  4. Unsupervised segmentation of lung fields in chest radiographs using multiresolution fractal feature vector and deformable models.

    PubMed

    Lee, Wen-Li; Chang, Koyin; Hsieh, Kai-Sheng

    2016-09-01

    Segmenting lung fields in a chest radiograph is essential for automatically analyzing an image. We present an unsupervised method based on multiresolution fractal feature vector. The feature vector characterizes the lung field region effectively. A fuzzy c-means clustering algorithm is then applied to obtain a satisfactory initial contour. The final contour is obtained by deformable models. The results show the feasibility and high performance of the proposed method. Furthermore, based on the segmentation of lung fields, the cardiothoracic ratio (CTR) can be measured. The CTR is a simple index for evaluating cardiac hypertrophy. After identifying a suspicious symptom based on the estimated CTR, a physician can suggest that the patient undergoes additional extensive tests before a treatment plan is finalized. PMID:26530048

  5. Stimulation of lung maturity: investigation of ambroxol in various animal models.

    PubMed

    von Seefeld, H; Weiss, J M; Eberhardt, H

    1985-01-01

    The surfactant or phospholipid lining of the alveolar surface is essential for lung function and airway stability. In premature neonates, the idiopathic respiratory distress syndrome (IRDS) is usually due to a prenatal deficiency in pulmonary surfactant. Experimental and clinical investigations with corticosteroids and other drugs were conducted to study various aspects of lung maturation. The present study of Ambroxol, a new compound with surfactant stimulating properties, was carried out on adult and foetal animals. In adult experimental animals an increase in the activity of Type II pneumocytes was shown by measuring various biochemical parameters. In models of premature animals comparable to clinical IRDS conditions, the antenatal treatment of foetal lambs and rabbits with Ambroxol enhanced lung maturation. PMID:3839344

  6. [A nonlinear multi-compartment lung model for optimization of breathing airflow pattern].

    PubMed

    Cai, Yongming; Gu, Lingyan; Chen, Fuhua

    2015-02-01

    It is difficult to select the appropriate ventilation mode in clinical mechanical ventilation. This paper presents a nonlinear multi-compartment lung model to solve the difficulty. The purpose is to optimize respiratory airflow patterns and get the minimum of the work of inspiratory phrase and lung volume acceleration, minimum of the elastic potential energy and rapidity of airflow rate changes of expiratory phrase. Sigmoidal function is used to smooth the respiratory function of nonlinear equations. The equations are established to solve nonlinear boundary conditions BVP, and finally the problem was solved with gradient descent method. Experimental results showed that lung volume and the rate of airflow after optimization had good sensitivity and convergence speed. The results provide a theoretical basis for the development of multivariable controller monitoring critically ill mechanically ventilated patients. PMID:25997262

  7. SN50, a Cell-Permeable Inhibitor of Nuclear Factor-κB, Attenuates Ventilator-Induced Lung Injury in an Isolated and Perfused Rat Lung Model.

    PubMed

    Chian, Chih-Feng; Chiang, Chi-Huei; Chuang, Chiao-Hui; Liu, Shiou-Ling; Tsai, Chen-Liang

    2016-08-01

    High tidal volume (VT) ventilation causes the release of various mediators and results in ventilator-induced lung injury (VILI). SN50, a cell-permeable nuclear factor-κB (NF-κB) inhibitory peptide, attenuates inflammation and acute respiratory distress syndrome. However, the mechanisms associated with the effects of SN50 in VILI have not been fully elucidated. We investigated the cellular and molecular mechanisms for the effects of SN50 treatment in VILI. An isolated and perfused rat lung model was exposed to low (5 mL/kg) or high (15 mL/kg) VT ventilation for 6 h. SN50 was administered in the perfusate at the onset of the high-stretch mechanical ventilation. The hemodynamics, lung histological changes, inflammatory responses, and activation of apoptotic pathways were evaluated. VILI was demonstrated by increased pulmonary vascular permeability and lung weight gain, as well as by increased levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, myeloperoxidase (MPO), hydrogen peroxide, and macrophage inflammatory protein-2 in the bronchoalveolar lavage fluid. The lung tissue expression of TNF-α, IL-1β, mitogen-activated protein kinases (MAPKs), caspase-3, and phosphorylation of serine/threonine-specific protein kinase (p-AKT) was greater in the high VT group than in the low VT group. Upregulation and activation of NF-κB was associated with increased lung injury in VILI. SN50 attenuated the inflammatory responses, including the expression of IL-1β, TNF-α, MPO, MAPKs, and NF-κB. In addition, the downregulation of apoptosis was evaluated using caspase-3 and p-AKT expression. Furthermore, SN50 mitigated the increases in the lung weights, pulmonary vascular permeability, and lung injury. In conclusion, VILI is associated with inflammatory responses and activation of NF-κB. SN50 inhibits the activation of NF-κB and attenuates VILI. PMID:26780513

  8. Incorporating epistasis interaction of genetic susceptibility single nucleotide polymorphisms in a lung cancer risk prediction model.

    PubMed

    Marcus, Michael W; Raji, Olaide Y; Duffy, Stephen W; Young, Robert P; Hopkins, Raewyn J; Field, John K

    2016-07-01

    Incorporation of genetic variants such as single nucleotide polymorphisms (SNPs) into risk prediction models may account for a substantial fraction of attributable disease risk. Genetic data, from 2385 subjects recruited into the Liverpool Lung Project (LLP) between 2000 and 2008, consisting of 20 SNPs independently validated in a candidate-gene discovery study was used. Multifactor dimensionality reduction (MDR) and random forest (RF) were used to explore evidence of epistasis among 20 replicated SNPs. Multivariable logistic regression was used to identify similar risk predictors for lung cancer in the LLP risk model for the epidemiological model and extended model with SNPs. Both models were internally validated using the bootstrap method and model performance was assessed using area under the curve (AUC) and net reclassification improvement (NRI). Using MDR and RF, the overall best classifier of lung cancer status were SNPs rs1799732 (DRD2), rs5744256 (IL-18), rs2306022 (ITGA11) with training accuracy of 0.6592 and a testing accuracy of 0.6572 and a cross-validation consistency of 10/10 with permutation testing P<0.0001. The apparent AUC of the epidemiological model was 0.75 (95% CI 0.73-0.77). When epistatic data were incorporated in the extended model, the AUC increased to 0.81 (95% CI 0.79-0.83) which corresponds to 8% increase in AUC (DeLong's test P=2.2e-16); 17.5% by NRI. After correction for optimism, the AUC was 0.73 for the epidemiological model and 0.79 for the extended model. Our results showed modest improvement in lung cancer risk prediction when the SNP epistasis factor was added. PMID:27121382

  9. Incorporating epistasis interaction of genetic susceptibility single nucleotide polymorphisms in a lung cancer risk prediction model

    PubMed Central

    MARCUS, MICHAEL W.; RAJI, OLAIDE Y.; DUFFY, STEPHEN W.; YOUNG, ROBERT P.; HOPKINS, RAEWYN J.; FIELD, JOHN K.

    2016-01-01

    Incorporation of genetic variants such as single nucleotide polymorphisms (SNPs) into risk prediction models may account for a substantial fraction of attributable disease risk. Genetic data, from 2385 subjects recruited into the Liverpool Lung Project (LLP) between 2000 and 2008, consisting of 20 SNPs independently validated in a candidate-gene discovery study was used. Multifactor dimensionality reduction (MDR) and random forest (RF) were used to explore evidence of epistasis among 20 replicated SNPs. Multivariable logistic regression was used to identify similar risk predictors for lung cancer in the LLP risk model for the epidemiological model and extended model with SNPs. Both models were internally validated using the bootstrap method and model performance was assessed using area under the curve (AUC) and net reclassification improvement (NRI). Using MDR and RF, the overall best classifier of lung cancer status were SNPs rs1799732 (DRD2), rs5744256 (IL-18), rs2306022 (ITGA11) with training accuracy of 0.6592 and a testing accuracy of 0.6572 and a cross-validation consistency of 10/10 with permutation testing P<0.0001. The apparent AUC of the epidemiological model was 0.75 (95% CI 0.73–0.77). When epistatic data were incorporated in the extended model, the AUC increased to 0.81 (95% CI 0.79–0.83) which corresponds to 8% increase in AUC (DeLong's test P=2.2e-16); 17.5% by NRI. After correction for optimism, the AUC was 0.73 for the epidemiological model and 0.79 for the extended model. Our results showed modest improvement in lung cancer risk prediction when the SNP epistasis factor was added. PMID:27121382

  10. Fractal Geometry Enables Classification of Different Lung Morphologies in a Model of Experimental Asthma

    NASA Astrophysics Data System (ADS)

    Obert, Martin; Hagner, Stefanie; Krombach, Gabriele A.; Inan, Selcuk; Renz, Harald

    2015-06-01

    Animal models represent the basis of our current understanding of the pathophysiology of asthma and are of central importance in the preclinical development of drug therapies. The characterization of irregular lung shapes is a major issue in radiological imaging of mice in these models. The aim of this study was to find out whether differences in lung morphology can be described by fractal geometry. Healthy and asthmatic mouse groups, before and after an acute asthma attack induced by methacholine, were studied. In vivo flat-panel-based high-resolution Computed Tomography (CT) was used for mice's thorax imaging. The digital image data of the mice's lungs were segmented from the surrounding tissue. After that, the lungs were divided by image gray-level thresholds into two additional subsets. One subset contained basically the air transporting bronchial system. The other subset corresponds mainly to the blood vessel system. We estimated the fractal dimension of all sets of the different mouse groups using the mass radius relation (mrr). We found that the air transporting subset of the bronchial lung tissue enables a complete and significant differentiation between all four mouse groups (mean D of control mice before methacholine treatment: 2.64 ± 0.06; after treatment: 2.76 ± 0.03; asthma mice before methacholine treatment: 2.37 ± 0.16; after treatment: 2.71 ± 0.03; p < 0.05). We conclude that the concept of fractal geometry allows a well-defined, quantitative numerical and objective differentiation of lung shapes — applicable most likely also in human asthma diagnostics.

  11. Lung Tumorigenesis in a Conditional Cul4A Transgenic Mouse Model

    PubMed Central

    Yang, Yi-Lin; Hung, Ming-Szu; Wang, Yang; Ni, Jian; Mao, Jian-Hua; Hsieh, David; Au, Alfred; Kumar, Atul; Quigley, David; Fang, Li Tai; Yeh, Che-Chung; Xu, Zhidong; Jablons, David M.; You, Liang

    2014-01-01

    Cullin4A (Cul4A) is a scaffold protein that assembles cullin-RING ubiquitin ligase (E3) complexes and regulates many cellular events, including cell survival, development, growth, and cell cycle control. Our previous study suggested that Cul4A is oncogenic in vitro, but its oncogenic role in vivo has not been studied. Here, we used a Cul4A transgenic mouse model to study the potential oncogenic role of Cul4A in lung tumor development. After Cul4A overexpression was induced in the lungs for 32 weeks, atypical epithelial cells were observed. After 40 weeks, lung tumors were visible and were characterized as Grade I or II adenocarcinomas. Immunohistochemistry (IHC) revealed decreased levels of Cul4A associated proteins p21CIP1 and tumor suppressor p19ARF in the lung tumors, suggesting Cul4A regulated their expression in these tumors. Increased levels of p27KIP1 and p16INK4a were also detected in these tumors. Moreover, protein level of DNA replication licensing factor CDT1 was decreased. Genomic instability in the lung tumors was further analyzed by the results from pericentrin protein expression and array Comparative Genomic Hybridization analysis. Furthermore, knocking down Cul4A expression in lung cancer H2170 cells increased their sensitivity to the chemotherapy drug cisplatin in vitro, suggesting that Cul4A overexpression is associated with cisplatin resistance in the cancer cells. Our findings indicate that Cul4A is oncogenic in vivo, and this Cul4A mouse model is a tool in understanding the mechanisms of Cul4A in human cancers and for testing experimental therapies targeting Cul4A. PMID:24648314

  12. A Human-Mouse Chimeric Model of Obliterative Bronchiolitis after Lung Transplantation

    PubMed Central

    Xue, Jianmin; Zhu, Xuehai; George, M. Patricia; Myerburg, Michael M.; Stoner, Michael W.; Pilewski, Joseph W.; Duncan, Steven R.

    2011-01-01

    Obliterative bronchiolitis is a frequent, morbid, and usually refractory complication of lung transplantation. Mechanistic study of obliterative bronchiolitis would be aided by development of a relevant model that uses human immune effector cells and airway targets. Our objective was to develop a murine chimera model that mimics obliterative bronchiolitis of lung allograft recipients in human airways in vivo. Human peripheral blood mononuclear cells were adoptively transferred to immunodeficient mice lacking activity of T, B, and NK cells, with and without concurrent transplantations of human small airways dissected from allogeneic cadaveric lungs. Chimerism with human T cells occurred in the majority of recipient animals. The chimeric T cells became highly activated, rapidly infiltrated into the small human airway grafts, and caused obliterative bronchiolitis. In contrast, airways implanted into control mice that did not also receive human peripheral blood mononuclear cell transfers remained intact. In vitro proliferation assays indicated that the chimeric T cells had enhanced specific proliferative responses to donor airway alloantigens. This model confirms the critical role of T cells in development of obliterative bronchiolitis among human lung allograft recipients and provides a novel and easily implemented mechanism for detailed, reductionist in vivo studies of human T-cell responses to allogeneic human small airways. PMID:21801868

  13. Lung cancer mortality trends in Chile and six-year projections using Bayesian dynamic linear models.

    PubMed

    Torres-Avilés, Francisco; Moraga, Tomás; Núñez, Loreto; Icaza, Gloria

    2015-09-01

    The objectives were to analyze lung cancer mortality trends in Chile from 1990 to 2009, and to project the rates six years forward. Lung cancer mortality data were obtained from the Chilean Ministry of Health. To obtain mortality rates, population projections were used, based on the 2002 National Census. Rates were adjusted using the world standard population as reference. Bayesian dynamic linear models were fitted to estimate trends from 1990 to 2009 and to obtain projections for 2010-2015. During the period under study, there was a 19.9% reduction in the lung cancer mortality rate in men. In women, there was increase of 28.4%. The second-order model showed a better fit for men, and the first-order model a better fit for women. Between 2010 and 2015 the downward trend continued in men, while a trend to stabilization was projected for lung cancer mortality in women in Chile. This analytical approach could be useful implement surveillance systems for chronic non-communicable disease and to evaluate preventive strategies. PMID:26578021

  14. Multiscale Airflow Model and Aerosol Deposition in Healthy and Emphysematous Rat Lungs

    NASA Astrophysics Data System (ADS)

    Oakes, Jessica; Marsden, Alison; Grandmont, Celine; Darquenne, Chantal; Vignon-Clementel, Irene

    2012-11-01

    The fate of aerosol particles in healthy and emphysematic lungs is needed to determine the toxic or therapeutic effects of inhalable particles. In this study we used a multiscale numerical model that couples a 0D resistance and capacitance model to 3D airways generated from MR images. Airflow simulations were performed using an in-house 3D finite element solver (SimVascular, simtk.org). Seven simulations were performed; 1 healthy, 1 uniform emphysema and 5 different cases of heterogeneous emphysema. In the heterogeneous emphysema cases the disease was confined to a single lobe. As a post processing step, 1 micron diameter particles were tracked in the flow field using Lagrangian particle tracking. The simulation results showed that the inhaled flow distribution was equal for the healthy and uniform emphysema cases. However, in the heterogeneous emphysema cases the delivery of inhaled air was larger in the diseased lobe. Additionally, there was an increase in delivery of aerosol particles to the diseased lobe. This suggests that as the therapeutic particles would reach the diseased areas of the lung, while toxic particles would increasingly harm the lung. The 3D-0D model described here is the first of its kind to be used to study healthy and emphysematic lungs. NSF Graduate Fellowship (Oakes), Burroughs Wellcome Fund (Marsden, Oakes) 1R21HL087805-02 from NHLBI at NIH, INRIA Team Grant.

  15. Development and validation of risk models to select ever-smokers for CT lung-cancer screening

    PubMed Central

    Katki, Hormuzd A.; Kovalchik, Stephanie A.; Berg, Christine D.; Cheung, Li C.; Chaturvedi, Anil K.

    2016-01-01

    Importance The US Preventive Services Task Force (USPSTF) recommends computed-tomography (CT) lung-cancer screening for ever-smokers ages 55-80 years who smoked at least 30 pack-years with no more than 15 years since quitting. However, selecting ever-smokers for screening using individualized lung-cancer risk calculations may be more effective and efficient than current USPSTF recommendations. Objective Comparison of modeled outcomes from risk-based CT lung-screening strategies versus USPSTF recommendations. Design/Setting/Participants Empirical risk models for lung-cancer incidence and death in the absence of CT screening using data on ever-smokers from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO; 1993-2009) control group. Covariates included age, education, sex, race, smoking intensity/duration/quit-years, Body Mass Index, family history of lung-cancer, and self-reported emphysema. Model validation in the chest radiography groups of the PLCO and the National Lung Screening Trial (NLST; 2002-2009), with additional validation of the death model in the National Health Interview Survey (NHIS; 1997-2001), a representative sample of the US. Models applied to US ever-smokers ages 50-80 (NHIS 2010-2012) to estimate outcomes of risk-based selection for CT lung-screening, assuming screening for all ever-smokers yields the percent changes in lung-cancer detection and death observed in the NLST. Exposure Annual CT lung-screening for 3 years. Main Outcomes and Measures Model validity: calibration (number of model-predicted cases divided by number of observed cases (Estimated/Observed)) and discrimination (Area-Under-Curve (AUC)). Modeled screening outcomes: estimated number of screen-avertable lung-cancer deaths, estimated screening effectiveness (number needed to screen (NNS) to prevent 1 lung-cancer death). Results Lung-cancer incidence and death risk models were well-calibrated in PLCO and NLST. The lung-cancer death model calibrated and

  16. High Inorganic Phosphate Intake Promotes Tumorigenesis at Early Stages in a Mouse Model of Lung Cancer.

    PubMed

    Lee, Somin; Kim, Ji-Eun; Hong, Seong-Ho; Lee, Ah-Young; Park, Eun-Jung; Seo, Hwi Won; Chae, Chanhee; Doble, Philip; Bishop, David; Cho, Myung-Haing

    2015-01-01

    Inorganic phosphate (Pi) is required by all living organisms for the development of organs such as bone, muscle, brain, and lungs, regulating the expression of several critical genes as well as signal transduction. However, little is known about the effects of prolonged dietary Pi consumption on lung cancer progression. This study investigated the effects of a high-phosphate diet (HPD) in a mouse model of adenocarcinoma. K-rasLA1 mice were fed a normal diet (0.3% Pi) or an HPD (1% Pi) for 1, 2, or 4 months. Mice were then sacrificed and subjected to inductively coupled plasma mass/optical emission spectrometry and laser ablation inductively coupled plasma mass-spectrometry analyses, western blot analysis, histopathological, immunohistochemical, and immunocytochemical analyses to evaluate tumor formation and progression (including cell proliferation, angiogenesis, and apoptosis), changes in ion levels and metabolism, autophagy, epithelial-to-mesenchymal transition, and protein translation in the lungs. An HPD accelerated tumorigenesis, as evidenced by increased adenoma and adenocarcinoma rates as well as tumor size. However, after 4 months of the HPD, cell proliferation was arrested, and marked increases in liver and lung ion levels and in energy production via the tricarboxylic acid cycle in the liver were observed, which were accompanied by increased autophagy and decreased angiogenesis and apoptosis. These results indicate that an HPD initially promotes but later inhibits lung cancer progression because of metabolic adaptation leading to tumor cell quiescence. Moreover, the results suggest that carefully regulated Pi consumption are effective in lung cancer prevention. PMID:26285136

  17. Surfactant dysfunction and lung inflammation in the female mouse model of lymphangioleiomyomatosis.

    PubMed

    Atochina-Vasserman, Elena N; Guo, Chang-Jiang; Abramova, Elena; Golden, Thea N; Sims, Michael; James, Melane L; Beers, Michael F; Gow, Andrew J; Krymskaya, Vera P

    2015-07-01

    Pulmonary lymphangioleiomyomatosis (LAM) is a rare lung disease caused by mutations of the tumor suppressor genes, tuberous sclerosis complex (TSC) 1 or TSC2. LAM affects women almost exclusively, and it is characterized by neoplastic growth of atypical smooth muscle-like TSC2-null LAM cells in the pulmonary interstitium, cystic destruction of lung parenchyma, and progressive decline in lung function. In this study, we hypothesized that TSC2-null lesions promote a proinflammatory environment, which contributes to lung parenchyma destruction. Using a TSC2-null female murine LAM model, we demonstrate that TSC2-null lesions promote alveolar macrophage accumulation, recruitment of immature multinucleated cells, an increased induction of proinflammatory genes, nitric oxide (NO) synthase 2, IL-6, chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemotactic protein 1 (MCP1), chemokine (C-X-C motif) ligand 1 (CXCL1)/keratinocyte chemoattractant (KC), and up-regulation of IL-6, KC, MCP-1, and transforming growth factor-β1 levels in bronchoalveolar lavage fluid. Bronchoalveolar lavage fluid also contained an increased level of surfactant protein (SP)-D, but not SP-A, significant reduction of SP-B levels, and a resultant increase in alveolar surface tension. Consistent with the growth of TSC2-null lesions, NO levels were also increased and, in turn, modified SP-D through S-nitrosylation, forming S-nitrosylated SP-D, a known consequence of lung inflammation. Progressive growth of TSC2-null lesions was accompanied by elevated levels of matrix metalloproteinase-3 and -9. This report demonstrates a link between growth of TSC2-null lesions and inflammation-induced surfactant dysfunction that might contribute to lung destruction in LAM. PMID:25474372

  18. Surfactant Dysfunction and Lung Inflammation in the Female Mouse Model of Lymphangioleiomyomatosis

    PubMed Central

    Guo, Chang-Jiang; Abramova, Elena; Golden, Thea N.; Sims, Michael; James, Melane L.; Beers, Michael F.; Gow, Andrew J.; Krymskaya, Vera P.

    2015-01-01

    Pulmonary lymphangioleiomyomatosis (LAM) is a rare lung disease caused by mutations of the tumor suppressor genes, tuberous sclerosis complex (TSC) 1 or TSC2. LAM affects women almost exclusively, and it is characterized by neoplastic growth of atypical smooth muscle–like TSC2-null LAM cells in the pulmonary interstitium, cystic destruction of lung parenchyma, and progressive decline in lung function. In this study, we hypothesized that TSC2-null lesions promote a proinflammatory environment, which contributes to lung parenchyma destruction. Using a TSC2-null female murine LAM model, we demonstrate that TSC2-null lesions promote alveolar macrophage accumulation, recruitment of immature multinucleated cells, an increased induction of proinflammatory genes, nitric oxide (NO) synthase 2, IL-6, chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemotactic protein 1 (MCP1), chemokine (C-X-C motif) ligand 1 (CXCL1)/keratinocyte chemoattractant (KC), and up-regulation of IL-6, KC, MCP-1, and transforming growth factor-β1 levels in bronchoalveolar lavage fluid. Bronchoalveolar lavage fluid also contained an increased level of surfactant protein (SP)-D, but not SP-A, significant reduction of SP-B levels, and a resultant increase in alveolar surface tension. Consistent with the growth of TSC2-null lesions, NO levels were also increased and, in turn, modified SP-D through S-nitrosylation, forming S-nitrosylated SP-D, a known consequence of lung inflammation. Progressive growth of TSC2-null lesions was accompanied by elevated levels of matrix metalloproteinase-3 and -9. This report demonstrates a link between growth of TSC2-null lesions and inflammation-induced surfactant dysfunction that might contribute to lung destruction in LAM. PMID:25474372

  19. Classification of lung cancer tumors based on structural and physicochemical properties of proteins by bioinformatics models.

    PubMed

    Hosseinzadeh, Faezeh; Ebrahimi, Mansour; Goliaei, Bahram; Shamabadi, Narges

    2012-01-01

    Rapid distinction between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) tumors is very important in diagnosis of this disease. Furthermore sequence-derived structural and physicochemical descriptors are very useful for machine learning prediction of protein structural and functional classes, classifying proteins and the prediction performance. Herein, in this study is the classification of lung tumors based on 1497 attributes derived from structural and physicochemical properties of protein sequences (based on genes defined by microarray analysis) investigated through a combination of attribute weighting, supervised and unsupervised clustering algorithms. Eighty percent of the weighting methods selected features such as autocorrelation, dipeptide composition and distribution of hydrophobicity as the most important protein attributes in classification of SCLC, NSCLC and COMMON classes of lung tumors. The same results were observed by most tree induction algorithms while descriptors of hydrophobicity distribution were high in protein sequences COMMON in both groups and distribution of charge in these proteins was very low; showing COMMON proteins were very hydrophobic. Furthermore, compositions of polar dipeptide in SCLC proteins were higher than NSCLC proteins. Some clustering models (alone or in combination with attribute weighting algorithms) were able to nearly classify SCLC and NSCLC proteins. Random Forest tree induction algorithm, calculated on leaves one-out and 10-fold cross validation) shows more than 86% accuracy in clustering and predicting three different lung cancer tumors. Here for the first time the application of data mining tools to effectively classify three classes of lung cancer tumors regarding the importance of dipeptide composition, autocorrelation and distribution descriptor has been reported. PMID:22829872

  20. High Inorganic Phosphate Intake Promotes Tumorigenesis at Early Stages in a Mouse Model of Lung Cancer

    PubMed Central

    Lee, Somin; Kim, Ji-Eun; Hong, Seong-Ho; Lee, Ah-Young; Park, Eun-Jung; Seo, Hwi Won; Chae, Chanhee; Doble, Philip; Bishop, David; Cho, Myung-Haing

    2015-01-01

    Inorganic phosphate (Pi) is required by all living organisms for the development of organs such as bone, muscle, brain, and lungs, regulating the expression of several critical genes as well as signal transduction. However, little is known about the effects of prolonged dietary Pi consumption on lung cancer progression. This study investigated the effects of a high-phosphate diet (HPD) in a mouse model of adenocarcinoma. K-rasLA1 mice were fed a normal diet (0.3% Pi) or an HPD (1% Pi) for 1, 2, or 4 months. Mice were then sacrificed and subjected to inductively coupled plasma mass/optical emission spectrometry and laser ablation inductively coupled plasma mass-spectrometry analyses, western blot analysis, histopathological, immunohistochemical, and immunocytochemical analyses to evaluate tumor formation and progression (including cell proliferation, angiogenesis, and apoptosis), changes in ion levels and metabolism, autophagy, epithelial-to-mesenchymal transition, and protein translation in the lungs. An HPD accelerated tumorigenesis, as evidenced by increased adenoma and adenocarcinoma rates as well as tumor size. However, after 4 months of the HPD, cell proliferation was arrested, and marked increases in liver and lung ion levels and in energy production via the tricarboxylic acid cycle in the liver were observed, which were accompanied by increased autophagy and decreased angiogenesis and apoptosis. These results indicate that an HPD initially promotes but later inhibits lung cancer progression because of metabolic adaptation leading to tumor cell quiescence. Moreover, the results suggest that carefully regulated Pi consumption are effective in lung cancer prevention. PMID:26285136

  1. Resident alveolar macrophages suppress while recruited monocytes promote allergic lung inflammation in murine models of asthma

    PubMed Central

    Zasłona, Zbigniew; Przybranowski, Sally; Wilke, Carol; van Rooijen, Nico; Teitz-Tennenbaum, Seagal; Osterholzer, John J.; Wilkinson, John E.; Moore, Bethany B.; Peters-Golden, Marc

    2014-01-01

    The role and origin of alveolar macrophages (AMs) in asthma are incompletely defined. We sought to clarify these issues in the context of acute allergic lung inflammation utilizing house dust mite and ovalbumin murine models. Use of liposomal clodronate to deplete resident AMs (rAMs) resulted in increased levels of inflammatory cytokines and eosinophil numbers in lavage fluid and augmented histopathologic evidence of lung inflammation, suggesting a suppressive role of rAMs. Lung digests of asthmatic mice revealed an increased percentage of Ly6Chigh/CD11bpos inflammatory monocytes. Clodronate depletion of circulating monocytes, by contrast, resulted in an attenuation of allergic inflammation. A CD45.1/CD45.2 chimera model demonstrated that recruitment at least partially contributes to the AM pool in irradiated non-asthmatic mice, but its contribution was no greater in asthma. Ki-67 staining of AMs supported a role for local proliferation, which was increased in asthma. Our data demonstrate that rAMs dampen, while circulating monocytes promote, early events in allergic lung inflammation. Moreover, maintenance of the AM pool in the early stages of asthmatic inflammation depends on local proliferation but not recruitment. PMID:25225663

  2. Measurement and mathematical modelling of elastic and resistive lung mechanical properties studied at sinusoidal expiratory flow.

    PubMed

    Bitzén, Ulrika; Niklason, Lisbet; Göransson, Ingegerd; Jonson, Björn

    2010-11-01

    Elastic pressure/volume (P(el) /V) and elastic pressure/resistance (P(el) /R) diagrams reflect parenchymal and bronchial properties, respectively. The objective was to develop a method for determination and mathematical characterization of P(el) /V and P(el) /R relationships, simultaneously studied at sinusoidal flow-modulated vital capacity expirations in a body plethysmograph. Analysis was carried out by iterative parameter estimation based on a composite mathematical model describing a three-segment P(el) /V curve and a hyperbolic P(el) /R curve. The hypothesis was tested that the sigmoid P(el) /V curve is non-symmetric. Thirty healthy subjects were studied. The hypothesis of a non-symmetric P(el) /V curve was verified. Its upper volume asymptote was nearly equal to total lung capacity (TLC), indicating lung stiffness increasing at high lung volume as the main factor limiting TLC at health. The asymptotic minimal resistance of the hyperbolic P(el) /R relationship reflected lung size. A detailed description of both P(el) /V and P(el) /R relationships was simultaneously derived from sinusoidal flow-modulated vital capacity expirations. The nature of the P(el) /V curve merits the use of a non-symmetric P(el) /V model. PMID:20726995

  3. The Effect of Different Doses of Cigarette Smoke in a Mouse Lung Tumor Model

    PubMed Central

    Santiago, Ludmilla Nadir; de Camargo Fenley, Juliana; Braga, Lúcia Campanario; Cordeiro, José Antônio; Cury, Patrícia M.

    2009-01-01

    Few studies have used Balb/c mice as an animal model for lung carcinogenesis. In this study, we investigated the effect of different doses of cigarette smoking in the urethane-induced Balb/c mouse lung cancer model. After injection of 3mg/kg urethane intraperitoneally, the mice were then exposed to tobacco smoke once or twice a day, five times a week, in a closed chamber. The animals were randomly divided into four groups. The control group (G0) received urethane only. The experimental groups (G1, G2 and G3) received urethane and exposure to the smoke of 3 cigarettes for 10 minutes once a day, 3 cigarettes for 10 minutes twice a day, and 6 cigarettes for 10 minutes twice a day, respectively. The mice were sacrificed after 16 weeks of exposure, and the number of nodules and hyperplasia in the lungs was counted. The results showed no statistically significant difference in the mean number of nodules and hyperplasia among the different groups, suggesting that the Balb/c mice are not suitable to study the pathogenesis of tobacco smoking-induced tumor progression in the lungs. PMID:19079653

  4. Model-based assessment of lung structures: inferencing and control system

    NASA Astrophysics Data System (ADS)

    Brown, Matthew S.; Gill, Robert W.; Talhami, H. E.; Wilson, Laurie S.; Doust, Bruce D.

    1995-05-01

    A general methodology has been developed for computer interpretation of medical images, based on an explicit anatomical model. A test system for analyzing posterior- anterior (PA) chest x-rays has been implemented. The inferencing and control system identifies the major lung structures in the image, and then flags any suspected abnormalities. Image and model data are transformed into a feature space where they are represented in terms of edge descriptions. The inference engine compares the image and model in feature space to label the edges anatomically, and check for normality. The control system schedules events within the inference engine and coordinates interaction with the model and image processing routines. The control architecture is blackboard-based, with a separate data frame for each structure to be identified. The anatomical model uses fuzzy sets to provide ranges of feature values which are considered normal or indicative of a particular abnormality. This allows the inference engine to give a confidence score and linguistic description to each decision. Mediastinum, cardiac border, domes of the diaphragm, ribs and lung outline have been modeled. Their automatic identification allows diagnostic checks such as the cardiothoracic ratio, comparison of right and left lungs to identify lobular collapse and inspection of interfaces in terms of shape and clarity. The inference engine provides simple comments on its findings, making it suitable for pre- and double-checking of images.

  5. IMPACT OF VENTILATION FREQUENCY AND PARENCHYMAL STIFFNESS ON FLOW AND PRESSURE DISTRIBUTION IN A CANINE LUNG MODEL

    PubMed Central

    Amini, Reza; Kaczka, David W.

    2013-01-01

    To determine the impact of ventilation frequency, lung volume, and parenchymal stiffness on ventilation distribution, we developed an anatomically-based computational model of the canine lung. Each lobe of the model consists of an asymmetric branching airway network subtended by terminal, viscoelastic acinar units. The model allows for empiric dependencies of airway segment dimensions and parenchymal stiffness on transpulmonary pressure. We simulated the effects of lung volume and parenchymal recoil on global lung impedance and ventilation distribution from 0.1 to 100 Hz, with mean transpulmonary pressures from 5 to 25 cmH2O. With increasing lung volume, the distribution of acinar flows narrowed and became more synchronous for frequencies below resonance. At higher frequencies, large variations in acinar flow were observed. Maximum acinar flow occurred at first antiresonance frequency, where lung impedance achieved a local maximum. The distribution of acinar pressures became very heterogeneous and amplified relative to tracheal pressure at the resonant frequency. These data demonstrate the important interaction between frequency and lung tissue stiffness on the distribution of acinar flows and pressures. These simulations provide useful information for the optimization of frequency, lung volume, and mean airway pressure during conventional ventilation or high frequency oscillation (HFOV). Moreover our model indicates that an optimal HFOV bandwidth exists between the resonant and antiresonant frequencies, for which interregional gas mixing is maximized. PMID:23872936

  6. Modelling staphylococcal pneumonia in a human 3D lung tissue model system delineates toxin-mediated pathology

    PubMed Central

    Mairpady Shambat, Srikanth; Chen, Puran; Nguyen Hoang, Anh Thu; Bergsten, Helena; Vandenesch, Francois; Siemens, Nikolai; Lina, Gerard; Monk, Ian R.; Foster, Timothy J.; Arakere, Gayathri; Svensson, Mattias; Norrby-Teglund, Anna

    2015-01-01

    ABSTRACT Staphylococcus aureus necrotizing pneumonia is recognized as a toxin-mediated disease, yet the tissue-destructive events remain elusive, partly as a result of lack of mechanistic studies in human lung tissue. In this study, a three-dimensional (3D) tissue model composed of human lung epithelial cells and fibroblasts was used to delineate the role of specific staphylococcal exotoxins in tissue pathology associated with severe pneumonia. To this end, the models were exposed to the mixture of exotoxins produced by S. aureus strains isolated from patients with varying severity of lung infection, namely necrotizing pneumonia or lung empyema, or to purified toxins. The necrotizing pneumonia strains secreted high levels of α-toxin and Panton-Valentine leukocidin (PVL), and triggered high cytotoxicity, inflammation, necrosis and loss of E-cadherin from the lung epithelium. In contrast, the lung empyema strain produced moderate levels of PVL, but negligible amounts of α-toxin, and triggered limited tissue damage. α-toxin had a direct damaging effect on the epithelium, as verified using toxin-deficient mutants and pure α-toxin. Moreover, PVL contributed to pathology through the lysis of neutrophils. A combination of α-toxin and PVL resulted in the most severe epithelial injury. In addition, toxin-induced release of pro-inflammatory mediators from lung tissue models resulted in enhanced neutrophil migration. Using a collection of 31 strains from patients with staphylococcal pneumonia revealed that strains producing high levels of α-toxin and PVL were cytotoxic and associated with fatal outcome. Also, the strains that produced the highest toxin levels induced significantly greater epithelial disruption. Of importance, toxin-mediated lung epithelium destruction could be inhibited by polyspecific intravenous immunoglobulin containing antibodies against α-toxin and PVL. This study introduces a novel model system for study of staphylococcal pneumonia in a human

  7. Evidence for basolateral but not apical membrane localization of outwardly rectifying depolarization-induced Cl(-) channel in airway epithelia.

    PubMed

    Hwang, T H; Lee, H J; Lee, N K; Choi, Y C

    2000-08-01

    The rat primary cultured-airway monolayer had been an excellent model for deciphering the ion channel after nystatin permeabilization of its basolateral or apical membrane (Hwang et al., 1996). After apical membrane permeabilization of rat primary cultured-airway monolayer, 4,4'-diisothiocyanatostilbene-2, 2'-disulfonic acid (DIDS)-sensitive outwardly rectifying depolarization-induced Cl(-) (BORDIC) currents were observed across the basolateral membrane in symmetrical NMG-Cl solution in this study. No significant Cl(-) current induced by the application of voltage clamping was observed across the apical membrane in symmetrical NMG-Cl solution after basolateral membrane permeabilization. The halide permeability sequence for BORDIC current was Br(-) = I(-) > Cl(-). BORDIC current was not affected by basolaterally applied bumetanide (0.5 mm). Basolateral DIDS (0.2 mm) but not apical DIDS inhibited CFTR mediated short-circuit current (I(sc)) in an intact monolayer of rat airway epithelia, a T84 human colonal epithelial cell line, and a Calu-3 human airway epithelial cell line. This is the first report showing that depolarization induced Cl(-) current is present on the basolateral membrane of airway epithelia. PMID:10931973

  8. Tree shrew as a new animal model for the study of lung cancer

    PubMed Central

    YE, LIANHUA; HE, MENG; HUANG, YUNCHAO; ZHAO, GUANGQIANG; LEI, YUJIE; ZHOU, YONGCHUN; CHEN, XIAOBO

    2016-01-01

    Animal models play a key role in identifying treatments for various types of cancer, including lung cancer. The aim of the present study was to develop a new animal model for lung cancer induction using tree shrews from the Yunnan region in China. Tree shrews are suitable for a full simulation of human disease because their structure, function and metabolism are adequately close to human. This animal may offer a new experimental animal model to be used in the study of lung cancer. In the present study, 80 healthy tree shrews were distributed in experimental and control groups. Animals in the experimental group received different concentrations of iodized oil suspension of 3-methylcholanthrene (3-MC) and diethylnitrosamine (DEN) while animals in the control groups received saline or lipiodol solvent via endotracheal instillation. In the 3rd, 5th, 7th, 9th and 11th weeks the body weights of the animals were measured and chest X-ray examinations were conducted. Pathological studies on the lung tissues were also performed and the pathological changes occurring in bronchial epithelium in all the groups were examined. Animals in the experimental group gradually lost their body weight. For tree shrews in the blank control and solvent control groups the survival rates were 100 and 80%, respectively while the survival rate for the experimental group was 0%. Results from the chest X-ray conducted on animals in the blank control and solvent control groups revealed no obvious abnormalities while in the experimental group high-density shadow spots within the perfusion sites were observed. Pathological studies performed on these high-density areas confirmed changes in the bronchial epithelium. In the experimental groups we also detected bronchial epithelial atypical hyperplasia, and apparent changes in carcinoma in situ. In conclusion, lung cancer was successfully induced in tree shrews by a one-time endotracheal introduction of iodized oil suspension of 3-MC and DEN. PMID

  9. Transepithelial migration of neutrophils into the lung requires TREM-1

    PubMed Central

    Klesney-Tait, Julia; Keck, Kathy; Li, Xiaopeng; Gilfillan, Susan; Otero, Karel; Baruah, Sankar; Meyerholz, David K.; Varga, Steven M.; Knudson, Cory J.; Moninger, Thomas O.; Moreland, Jessica; Zabner, Joseph; Colonna, Marco

    2012-01-01

    Acute respiratory infections are responsible for more than 4 million deaths each year. Neutrophils play an essential role in the innate immune response to lung infection. These cells have an armamentarium of pattern recognition molecules and antimicrobial agents that identify and eliminate pathogens. In the setting of infection, neutrophil triggering receptor expressed on myeloid cells 1 (TREM-1) amplifies inflammatory signaling. Here we demonstrate for the first time that TREM-1 also plays an important role in transepithelial migration of neutrophils into the airspace. We developed a TREM-1/3–deficient mouse model of pneumonia and found that absence of TREM-1/3 markedly increased mortality following Pseudomonas aeruginosa challenge. Unexpectedly, TREM-1/3 deficiency resulted in increased local and systemic cytokine production. TREM-1/3–deficient neutrophils demonstrated intact bacterial killing, phagocytosis, and chemotaxis; however, histologic examination of TREM-1/3–deficient lungs revealed decreased neutrophil infiltration of the airways. TREM-1/3–deficient neutrophils effectively migrated across primary endothelial cell monolayers but failed to migrate across primary airway epithelia grown at the air-liquid interface. These data define a new function for TREM-1 in neutrophil migration across airway epithelial cells and suggest that it amplifies inflammation through targeted neutrophil migration into the lung. PMID:23241959

  10. Role of TNFR1 in lung injury and altered lung function induced by the model sulfur mustard vesicant, 2-chloroethyl ethyl sulfide

    SciTech Connect

    Sunil, Vasanthi R.; Patel-Vayas, Kinal; Shen, Jianliang; Gow, Andrew J.; Laskin, Jeffrey D.; Laskin, Debra L.

    2011-02-01

    Lung toxicity induced by sulfur mustard is associated with inflammation and oxidative stress. To elucidate mechanisms mediating pulmonary damage, we used 2-chloroethyl ethyl sulfide (CEES), a model sulfur mustard vesicant. Male mice (B6129) were treated intratracheally with CEES (3 or 6 mg/kg) or control. Animals were sacrificed 3, 7 or 14 days later and bronchoalveolar lavage (BAL) fluid and lung tissue collected. Treatment of mice with CEES resulted in an increase in BAL protein, an indication of alveolar epithelial damage, within 3 days. Expression of Ym1, an oxidative stress marker also increased in the lung, along with inducible nitric oxide synthase, and at 14 days, cyclooxygenase-2 and monocyte chemotactic protein-1, inflammatory proteins implicated in tissue injury. These responses were attenuated in mice lacking the p55 receptor for TNF{alpha} (TNFR1-/-), demonstrating that signaling via TNFR1 is key to CEES-induced injury, oxidative stress, and inflammation. CEES-induced upregulation of CuZn-superoxide dismutase (SOD) and MnSOD was delayed or absent in TNFR1-/- mice, relative to WT mice, suggesting that TNF{alpha} mediates early antioxidant responses to lung toxicants. Treatment of WT mice with CEES also resulted in functional alterations in the lung including decreases in compliance and increases in elastance. Additionally, methacholine-induced alterations in total lung resistance and central airway resistance were dampened by CEES. Loss of TNFR1 resulted in blunted functional responses to CEES. These effects were most notable in the airways. These data suggest that targeting TNF{alpha} signaling may be useful in mitigating lung injury, inflammation and functional alterations induced by vesicants.

  11. A Minimal Path Searching Approach for Active Shape Model (ASM)-based Segmentation of the Lung.

    PubMed

    Guo, Shengwen; Fei, Baowei

    2009-03-27

    We are developing a minimal path searching method for active shape model (ASM)-based segmentation for detection of lung boundaries on digital radiographs. With the conventional ASM method, the position and shape parameters of the model points are iteratively refined and the target points are updated by the least Mahalanobis distance criterion. We propose an improved searching strategy that extends the searching points in a fan-shape region instead of along the normal direction. A minimal path (MP) deformable model is applied to drive the searching procedure. A statistical shape prior model is incorporated into the segmentation. In order to keep the smoothness of the shape, a smooth constraint is employed to the deformable model. To quantitatively assess the ASM-MP segmentation, we compare the automatic segmentation with manual segmentation for 72 lung digitized radiographs. The distance error between the ASM-MP and manual segmentation is 1.75 ± 0.33 pixels, while the error is 1.99 ± 0.45 pixels for the ASM. Our results demonstrate that our ASM-MP method can accurately segment the lung on digital radiographs. PMID:24386531

  12. A minimal path searching approach for active shape model (ASM)-based segmentation of the lung

    NASA Astrophysics Data System (ADS)

    Guo, Shengwen; Fei, Baowei

    2009-02-01

    We are developing a minimal path searching method for active shape model (ASM)-based segmentation for detection of lung boundaries on digital radiographs. With the conventional ASM method, the position and shape parameters of the model points are iteratively refined and the target points are updated by the least Mahalanobis distance criterion. We propose an improved searching strategy that extends the searching points in a fan-shape region instead of along the normal direction. A minimal path (MP) deformable model is applied to drive the searching procedure. A statistical shape prior model is incorporated into the segmentation. In order to keep the smoothness of the shape, a smooth constraint is employed to the deformable model. To quantitatively assess the ASM-MP segmentation, we compare the automatic segmentation with manual segmentation for 72 lung digitized radiographs. The distance error between the ASM-MP and manual segmentation is 1.75 +/- 0.33 pixels, while the error is 1.99 +/- 0.45 pixels for the ASM. Our results demonstrate that our ASM-MP method can accurately segment the lung on digital radiographs.

  13. Viscoelastic Model for Lung Parenchyma for Multi-Scale Modeling of Respiratory System Phase I: Hypo-Elastic Model for CFD Implementation

    SciTech Connect

    Freed, Alan D.; Einstein, Daniel R.

    2011-04-14

    An isotropic constitutive model for the parenchyma of lung has been derived from the theory of hypo-elasticity. The intent is to use it to represent the mechanical response of this soft tissue in sophisticated, computational, fluid-dynamic models of the lung. This demands that the continuum model be accurate, yet simple and effcient. An objective algorithm for its numeric integration is provided. The response of the model is determined for several boundary-value problems whose experiments are used for material characterization. The effective elastic, bulk, and shear moduli, and Poisson’s ratio, as tangent functions, are also derived. The model is characterized against published experimental data for lung. A bridge between this continuum model and a dodecahedral model of alveolar geometry is investigated, with preliminary findings being reported.

  14. RC-3095, a Selective Gastrin-Releasing Peptide Receptor Antagonist, Does Not Protect the Lungs in an Experimental Model of Lung Ischemia-Reperfusion Injury

    PubMed Central

    Oliveira-Freitas, Vera L.; Thomaz, Leonardo Dalla Giacomassa Rocha; Simoneti, Lucas Elias Lise; Malfitano, Christiane; De Angelis, Kátia; Ulbrich, Jane Maria; Schwartsmann, Gilberto; Andrade, Cristiano Feijó

    2015-01-01

    RC-3095, a selective GRPR antagonist, has been shown to have anti-inflammatory properties in different models of inflammation. However, its protective effect on lungs submitted to lung ischemia-reperfusion injury has not been addressed before. Then, we administrated RC-3095 intravenously before and after lung reperfusion using an animal model of lung ischemia-reperfusion injury (LIRI) by clamping the pulmonary hilum. Twenty Wistar rats were subjected to an experimental model in four groups: SHAM, ischemia-reperfusion (IR), RC-Pre, and RC-Post. The final mean arterial pressure significantly decreased in IR and RC-Pre compared to their values before reperfusion (P < 0.001). The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation when compared to baseline (P = 0.005). Caspase-9 activity was significantly higher in the RC-Post as compared to the other groups (P < 0.013). No significant differences were observed in eNOS activity among the groups. The groups RC-Pre and RC-Post did not show any significant decrease in IL-1β (P = 0.159) and TNF-α (P = 0.260), as compared to IR. The histological score showed no significant differences among the groups. In conclusion, RC-3095 does not demonstrate a protective effect in our LIRI model. Additionally, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis. PMID:25893195

  15. Development and Evolution of Inner Ear Sensory Epithelia and Their Innervation

    PubMed Central

    Fritzsch, B.; Beisel, K. W.; Jones, K.; Fariñas, I.; Maklad, A.; Lee, J.; Reichardt, L. F.

    2013-01-01

    The development and evolution of the inner ear sensory patches and their innervation is reviewed. Recent molecular developmental data suggest that development of these sensory patches is a developmental recapitulation of the evolutionary history. These data suggest that the ear generates multiple, functionally diverse sensory epithelia by dividing a single sensory primordium. Those epithelia will establish distinct identities through the overlapping expression of genes of which only a few are currently known. One of these distinctions is the unique pattern of hair cell polarity. A hypothesis is presented on how the hair cell polarity may relate to the progressive segregation of the six sensory epithelia. Besides being markers for sensory epithelia development, neurotrophins are also expressed in delaminating cells that migrate toward the developing vestibular and cochlear ganglia. These delaminating cells originate from multiple sites at or near the developing sensory epithelia and some also express neuronal markers such as NeuroD. The differential origin of precursors raises the possibility that some sensory neurons acquire positional information before they delaminate the ear. Such an identity of these delaminating sensory neurons may be used both to navigate their dendrites to the area they delaminated from, as well as to help them navigate to their central target. The navigational properties of sensory neurons as well as the acquisition of discrete sensory patch phenotypes implies a much more sophisticated subdivision of the developing otocyst than the few available gene expression studies suggest. PMID:12382272

  16. A decremental PEEP trial for determining open-lung PEEP in a rabbit model of acute lung injury.

    PubMed

    Hua, Yi-Ming; Lien, Shao-Hung; Liu, Tao-Yuan; Lee, Chuen-Ming; Yuh, Yeong-Seng

    2008-04-01

    A positive end-expiratory pressure (PEEP) above the lower inflection point (LIP) of the pressure-volume curve has been thought necessary to maintain recruited lung volume in acute lung injury (ALI). We used a strategy to identify the level of open-lung PEEP (OLP) by detecting the maximum tidal compliance during a decremental PEEP trial (DPT). We performed a randomized controlled study to compare the effect of the OLP to PEEP above LIP and zero PEEP on pulmonary mechanics, gas exchange, hemodynamic change, and lung injury in 26 rabbits with ALI. After recruitment maneuver, the lavage-injured rabbits received DPTs to identify the OLP. Animals were randomized to receive volume controlled ventilation with either: (a) PEEP = 0 cm H2O (ZEEP); (b) PEEP = 2 cm H2O above OLP (OLP + 2); or (c) PEEP = 2 cm H2O above LIP (LIP + 2). Peak inspiratory pressure and mean airway pressure were recorded and arterial blood gases were analyzed every 30 min. Mean blood pressure and heart rate were monitored continuously. Lung injury severity was assessed by lung wet/dry weight ratio. Animals in OLP + 2 group had less lung injury as well as relatively better compliance, more stable pH, and less hypercapnia compared to the LIP + 2 and ZEEP groups. We concluded that setting PEEP according to the OLP identified by DPTs is an effective method to attenuate lung injury. This strategy could be used as an indicator for optimal PEEP. The approach is simple and noninvasive and may be of clinical interest. PMID:18293413

  17. Characterization of a nose-only inhaled phosgene acute lung injury mouse model

    PubMed Central

    Plahovinsak, Jennifer L.; Perry, Mark R.; Knostman, Katherine A.; Segal, Robert; Babin, Michael C.

    2016-01-01

    Context Phosgene’s primary mode of action is as a pulmonary irritant characterized by its early latent phase where life-threatening, non-cardiogenic pulmonary edema is typically observed 6–24 h post-exposure. Objective To develop an inhaled phosgene acute lung injury (ALI) model in C57BL/6 mice that can be used to screen potential medical countermeasures. Methods A Cannon style nose-only inhalation exposure tower was used to expose mice to phosgene (8 ppm) or air (sham). An inhalation lethality study was conducted to determine the 8 ppm median lethal exposure (LCt50) at 24 and 48 h post-exposure. The model was then developed at 1.2 times the 24 h LCt50. At predetermined serial sacrifice time points, survivors were euthanized, body and lung weights collected, and lung tissues processed for histopathology. Additionally, post-exposure clinical observations were used to assess quality of life. Results and discussion The 24-hour LCt50 was 226ppm*min (8 ppm for 28.2 min) and the 48-hour LCt50 was 215ppm*min (8 ppm for 26.9 min). The phosgene exposed animals had a distinct progression of clinical signs, histopathological changes and increased lung/body weight ratios. Early indicators of a 1.2 times the 24-hour LCt50 phosgene exposure were significant changes in the lung-to-body weight ratios by 4 h post-exposure. The progression of clinical signs and histopathological changes were important endpoints for characterizing phosgene-induced ALI for future countermeasure studies. Conclusion An 8 ppm phosgene exposure for 34 min (1.2 × LCt50) is the minimum challenge recommended for evaluating therapeutic interventions. The predicted higher mortality in the phosgene-only controls will help demonstrate efficacy of candidate treatments and increase the probability that a change in survival rate is statistically significant PMID:26671199

  18. Scaling of lunge feeding in rorqual whales: an integrated model of engulfment duration.

    PubMed

    Potvin, J; Goldbogen, J A; Shadwick, R E

    2010-12-01

    Rorqual whales (Balaenopteridae) obtain their food by lunge feeding, a dynamic process that involves the intermittent engulfment and filtering of large amounts of water and prey. During a lunge, whales accelerate to high speed and open their mouth wide, thereby exposing a highly distensible buccal cavity to the flow and facilitating its inflation. Unsteady hydrodynamic models suggest that the muscles associated with the ventral groove blubber undergo eccentric contraction in order to stiffen and control the inflation of the buccal cavity; in doing so the engulfed water mass is accelerated forward as the whale's body slows down. Although the basic mechanics of lunge feeding are relatively well known, the scaling of this process remains poorly understood, particularly with regards to its duration (from mouth opening to closure). Here we formulate a new theory of engulfment time which integrates prey escape behavior with the mechanics of the whale's body, including lunge speed and acceleration, gape angle dynamics, and the controlled inflation of the buccal cavity. Given that the complex interaction between these factors must be highly coordinated in order to maximize engulfment volume, the proposed formulation rests on the scenario of Synchronized Engulfment, whereby the filling of the cavity (posterior to the temporomandibular joint) coincides with the moment of maximum gape. When formulated specifically for large rorquals feeding on krill, our analysis predicts that engulfment time increases with body size, but in amounts dictated by the specifics of krill escape and avoidance kinematics. The predictions generated by the model are corroborated by limited empirical data on a species-specific basis, particularly for humpback and blue whales chasing krill. A sensitivity analysis applied to all possible sized fin whales also suggests that engulfment duration and lunge speed will increase intra-specifically with body size under a wide range of predator-prey scenarios

  19. Extent of Spine Deformity Predicts Lung Growth and Function in Rabbit Model of Early Onset Scoliosis

    PubMed Central

    Olson, J. Casey; Takahashi, Ayuko; Glotzbecker, Michael P.; Snyder, Brian D.

    2015-01-01

    Early onset deformity of the spine and chest wall (initiated <8 years of age) is associated with increased morbidity at adulthood relative to adolescent onset deformity of comparable severity. Presumably, inhibition of thoracic growth during late stage alveolarization leads to an irreversible loss of pulmonary growth and thoracic function; however the natural history of this disease from onset to adulthood has not been well characterized. In this study we establish a rabbit model of early onset scoliosis to establish the extent that thoracic deformity affects structural and functional respiratory development. Using a surgical right unilateral rib-tethering procedure, rib fusion with early onset scoliosis was induced in 10 young New Zealand white rabbits (3 weeks old). Progression of spine deformity, functional residual capacity, total lung capacity, and lung mass was tracked through longitudinal breath-hold computed tomography imaging up to skeletal maturity (28 weeks old). Additionally at maturity forced vital capacity and regional specific volume were calculated as functional measurements and histo-morphometry performed with the radial alveolar count as a measure of acinar complexity. Data from tethered rib rabbits were compared to age matched healthy control rabbits (N = 8). Results show unilateral rib-tethering created a progressive spinal deformity ranging from 30° to 120° curvature, the severity of which was strongly associated with pulmonary growth and functional outcomes. At maturity rabbits with deformity greater than the median (55°) had decreased body weight (89%), right (59%) and left (86%) lung mass, right (74%) and left (69%) radial alveolar count, right lung volume at total lung capacity (60%), and forced vital capacity (75%). Early treatment of spinal deformity in children may prevent pulmonary complications in adulthood and these results provide a basis for the prediction of pulmonary development from thoracic structure. This model may also have

  20. Treatment of malignant effusion by oncolytic virotherapy in an experimental subcutaneous xenograft model of lung cancer

    PubMed Central

    2013-01-01

    Background Malignant pleural effusion (MPE) is associated with advanced stages of lung cancer and is mainly dependent on invasion of the pleura and expression of vascular endothelial growth factor (VEGF) by cancer cells. As MPE indicates an incurable disease with limited palliative treatment options and poor outcome, there is an urgent need for new and efficient treatment options. Methods In this study, we used subcutaneously generated PC14PE6 lung adenocarcinoma xenografts in athymic mice that developed subcutaneous malignant effusions (ME) which mimic pleural effusions of the orthotopic model. Using this approach monitoring of therapeutic intervention was facilitated by direct observation of subcutaneous ME formation without the need of sacrificing mice or special imaging equipment as in case of MPE. Further, we tested oncolytic virotherapy using Vaccinia virus as a novel treatment modality against ME in this subcutaneous PC14PE6 xenograft model of advanced lung adenocarcinoma. Results We demonstrated significant therapeutic efficacy of Vaccinia virus treatment of both advanced lung adenocarcinoma and tumor-associated ME. We attribute the efficacy to the virus-mediated reduction of tumor cell-derived VEGF levels in tumors, decreased invasion of tumor cells into the peritumoral tissue, and to viral infection of the blood vessel-invading tumor cells. Moreover, we showed that the use of oncolytic Vaccinia virus encoding for a single-chain antibody (scAb) against VEGF (GLAF-1) significantly enhanced mono-therapy of oncolytic treatment. Conclusions Here, we demonstrate for the first time that oncolytic virotherapy using tumor-specific Vaccinia virus represents a novel and promising treatment modality for therapy of ME associated with advanced lung cancer. PMID:23635329

  1. Prediction of particle deposition in the lungs based on simple modeling of alveolar mixing.

    PubMed

    Georgakakou, S; Gourgoulianis, K; Daniil, Z; Bontozoglou, V

    2016-05-01

    A simplified model of particle deposition in the lungs has been developed and implemented, based on the hypothesis that perfect mixing takes place in the alveolar volume of each airway generation. This key idea is combined with purely convective transport along airways, driven by steady alveolar expansion and contraction, and results in an analytically tractable model. Predictions of the model, and in particular pulmonary deposition, are found in very good agreement with detailed benchmark data in the literature for particle diameters d≥0.1μm. The success of this simple model provides indirect evidence in favor of the role of alveolar mixing in the deposition process. PMID:26790361

  2. Cathepsin B, cathepsin L, and cystatin C in the porcine uterus and placenta: potential roles in endometrial/placental remodeling and in fluid-phase transport of proteins secreted by uterine epithelia across placental areolae.

    PubMed

    Song, Gwonhwa; Bailey, Daniel W; Dunlap, Kathrin A; Burghardt, Robert C; Spencer, Thomas E; Bazer, Fuller W; Johnson, Greg A

    2010-05-01

    Cathepsins (CTSB and CTSL1) and their inhibitor, cystatin C (CST3), remodel uterine endometrium and placenta for transport of gases, micronutrients, and macromolecules essential for development and growth of the conceptus (embryo/fetus and placental membranes). We examined the temporal/spatial control of expression for CTSB, CTSL1, and CST3 mRNAs in endometria and placentae of pigs using three developmental models: 1) pigs were hysterectomized during the estrous cycle or pregnancy; 2) cyclic pigs were injected with estrogen to induce pseudopregnancy and were hysterectomized; and 3) pigs were ovariectomized, injected with progesterone, and hysterectomized. The abundance of CTSB, CTSL1, and CST3 mRNAs increased in endometrial epithelia during pregnancy and in response to exogenous progesterone but not estrogen. CST3 was also expressed in cells scattered within the stratum compactum stroma. Progesterone decreased epithelial but increased stromal compartment expression of CST3. CTSB increased in all chorionic epithelia, but CTSL1 was limited to chorionic epithelia that form areolae to absorb secretions from uterine glands. Based on the placental and endometrial distribution of CTSL1, we examined expression in the neonatal enterocytes known to transport immunoglobulins from colostrum. CTSL1 was also expressed in enterocytes of intestine from neonatal piglets. Therefore, CTSL1 is expressed by endometrial epithelia, placental areolae, and neonatal intestine, and it may function in the transport of macromolecules across these epithelia. Our results support the idea that reciprocal interactions between CSTL1, CTSB, and CST3 may be required to remodel endometrial and placental tissues for close apposition between maternal and fetal vasculatures and to facilitate transplacental transport of gases, micronutrients (amino acids, glucose), and macromolecules (proteins). Cysteine proteases and their inhibitors may also specifically modify proteins for successful utilization and

  3. Pulmonary toxicity in a rabbit model of stereotactic lung radiation therapy: efficacy of a radioprotector.

    PubMed

    Mata, Jaime; Sheng, Ke; Hagspiel, Klaus; Ruppert, Kai; Sylvester, Peter; Mugler, John; Fernandes, Carolina; Guan, Steven; Larner, James; Read, Paul

    2014-08-01

    This study aimed to assess the efficacy of the radioprotector amifostine in limiting radiation toxicity in a rabbit model of lung stereotactic body radiation therapy (SBRT) by correlating contrast-enhanced magnetic resonance angiography (ce-MRA), computed tomography (CT), and helium-3 (He-3) magnetic resonance imaging (MRI) with histopathology. Multiple MRI techniques were tested to obtain complementing physiologic information. Thirteen rabbits received SBRT to the right lower lobe of the lung. Specifically, 4 received 3 × 11 Gray (Gy), 6 received 3 × 11 Gy and 50 mg/kg of amifostine pre-SRBT, and 3 received 3 × 7, 3 × 9, or 3 × 13 Gy. Imaging was performed at baseline and 4, 8, 12, and 16 weeks post-SBRT. Ce-MRA perfusion difference between lungs in the irradiated group at 16 weeks post-treatment was statistically significant (P = .04) whereas the difference in the irradiated + amifostine group was not (P = .30). Histologically observed low red blood cell (RBC) count and CT hypodensity suggests changes were primarily related to perfusion; however, structural changes, such as increased alveolar size, were also present. No changes in He-3 MRI lung ventilation were observed in either group. Although radiation-induced injury detected in rabbits as CT hypodensity contrasted with increased density observed in humans/rodents, the changes in ce-MRA and CT were still significantly reduced after the addition of amifostine to SBRT. Use of CT and selected MRI techniques helped to pinpoint primary physiologic changes. PMID:24926529

  4. Activated protein C attenuates acute lung injury and apoptosis in a hyperoxic animal model.

    PubMed

    Husari, Ahmad W; Khayat, Aline; Awdeh, Haitham; Hatoum, Hadi; Nasser, Michel; Mroueh, Salman M; Zaatari, Ghazi; El-Sabban, Marwan; Dbaibo, Ghassan S

    2010-05-01

    Evidence suggests that activated protein C (APC) attenuates acute lung injury (ALI) through antithrombotic and anti-inflammatory mechanisms. The aim of this study was to determine the effects of APC on ALI in adult rats exposed to hyperoxic environment. Rats were divided into control, hyperoxia, hyperoxia + APC, and APC. Hyperoxia and hyperoxia + APC were exposed to 1, 3, and 5 days of hyperoxia. Hyperoxia + APC and APC were injected with APC (5 mg/kg, i.p.) every 12 h. Control and hyperoxia received isotonic sodium chloride solution injection. Measurement of wet to dry ratio and albumin leak demonstrated significant improvement in hyperoxia + APC when compared with hyperoxia. Apoptosis, as measured by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, was significantly reduced in hyperoxia + APC when compared with hyperoxia. Histological evaluation of lung sections showed significant reduction in inflammation, edema, and in the number of marginating neutrophils in hyperoxia + APC as compared with hyperoxia. Transcriptional expression of lung inflammatory mediators demonstrated a time-dependent surge in the levels TNF-alpha, IL-1beta, and IL-6 in response to hyperoxia that was attenuated with APC administration in the presence of hyperoxia. In this rat model, APC attenuates lung injury and the expression of inflammatory mediators in ALI secondary to hyperoxia. PMID:19851127

  5. Use of multiphoton microscopy to diagnose liver cancer and lung metastasis in an orthotopic rat model.

    PubMed

    Yan, Jun; Zhuo, Shuangmu; Chen, Gang; Tan, Changjun; Zhu, Weifeng; Lu, Jianping; Fan, Jia; Chen, Jianxin; Zhou, Jian

    2012-01-01

    Liver or lung biopsy for suspicious lesions has several disadvantages such as bleeding, bile leak or pneumothorax, needle track seeding, and time-consuming histopathological procedure. The ability to directly observe cellular and subcellular details and then perform "optical biopsy" is a major goal in the development of new interventional techniques. Multiphoton microscopy (MPM) enables real-time noninvasive visualization of tissue architecture and cell morphology in live tissue. We performed a study to evaluate whether MPMcan make real-time optical diagnosis for liver cancer and lung metastasis using an orthotopic rat model with Morris hepatoma. We found that real-time high-resolution MPMimaging could clearly show tissue architecture and cell morphology. In the normal liver tissue, MPMimaging clearly revealed the blood-filled sinusoids and cords of hepatocytes. In the cancerous tissue, MPMimaging clearly illustrated that cancer cells displayed marked cellular and nuclear pleomorphism. MPMimages were comparable to golden standard hematoxylin-eosin staining images. Moreover, MPMimaging had deep penetration with the capability of optical sectioning. In short, MPMcan make real-time optical diagnosis for liver cancer and lung metastasis. This study provides the groundwork for further using multiphoton endoscopy to perform real-time noninvasive "optical biopsy" for liver cancer and lung metastasis in the near future. PMID:22331704

  6. Stable Small Animal Ventilation for Dynamic Lung Imaging to Support Computational Fluid Dynamics Models

    PubMed Central

    Jacob, Richard E.; Lamm, Wayne J.

    2011-01-01

    Pulmonary computational fluid dynamics models require that three-dimensional images be acquired over multiple points in the dynamic breathing cycle without breath holds or changes in ventilatory mechanics. With small animals, these requirements can result in long imaging times (∼90 minutes), over which lung mechanics, such as compliance, may gradually change if not carefully monitored and controlled. These changes, caused by derecruitment of parenchymal tissue, are manifested as an upward drift in peak inspiratory pressure (PIP) or by changes in the pressure waveform and/or lung volume over the course of the experiment. We demonstrate highly repeatable mechanical ventilation in anesthetized rats over a long duration for dynamic lung x-ray computed tomography (CT) imaging. We describe significant updates to a basic commercial ventilator that was acquired for these experiments. Key to achieving consistent results was the implementation of periodic deep breaths, or sighs, of extended duration to maintain lung recruitment. In addition, continuous monitoring of breath-to-breath pressure and volume waveforms and long-term trends in PIP and flow provide diagnostics of changes in breathing mechanics. PMID:22087338

  7. Fluid transport in branched structures with temporary closures: A model for quasistatic lung inflation

    NASA Astrophysics Data System (ADS)

    Majumdar, Arnab; Alencar, Adriano M.; Buldyrev, Sergey V.; Hantos, Zoltán; Stanley, H. Eugene; Suki, Béla

    2003-03-01

    We analyze the problem of fluid transport through a model system relevant to the inflation of a mammalian lung, an asymmetric bifurcating structure containing random blockages that can be removed by the pressure of the fluid itself. We obtain a comprehensive description of the fluid flow in terms of the topology of the structure and the mechanisms which open the blockages. We show that when calculating averaged flow properties of the fluid, the tree structure can be partitioned into a linear superposition of one-dimensional chains. In particular, we relate the pressure-volume P-V relationship of the fluid to the distribution Π(n) of the generation number n of the tree’s terminal branches, a structural property. We invert this relation to obtain a statistical description of the underlying branching structure of the lung, by analyzing experimental pressure-volume data from dog lungs. The Π(n) extracted from the experimental P-V data agrees well with available data on lung branching structure. Our general results are applicable to any physical system involving transport in bifurcating structures with removable closures.

  8. Predicting lung dosimetry of inhaled particleborne benzo[a]pyrene using physiologically based pharmacokinetic modeling.

    PubMed

    Campbell, Jerry; Franzen, Allison; Van Landingham, Cynthia; Lumpkin, Michael; Crowell, Susan; Meredith, Clive; Loccisano, Anne; Gentry, Robinan; Clewell, Harvey

    2016-09-01

    Benzo[a]pyrene (BaP) is a by-product of incomplete combustion of fossil fuels and plant/wood products, including tobacco. A physiologically based pharmacokinetic (PBPK) model for BaP for the rat was extended to simulate inhalation exposures to BaP in rats and humans including particle deposition and dissolution of absorbed BaP and renal elimination of 3-hydroxy benzo[a]pyrene (3-OH BaP) in humans. The clearance of particle-associated BaP from lung based on existing data in rats and dogs suggest that the process is bi-phasic. An initial rapid clearance was represented by BaP released from particles followed by a slower first-order clearance that follows particle kinetics. Parameter values for BaP-particle dissociation were estimated using inhalation data from isolated/ventilated/perfused rat lungs and optimized in the extended inhalation model using available rat data. Simulations of acute inhalation exposures in rats identified specific data needs including systemic elimination of BaP metabolites, diffusion-limited transfer rates of BaP from lung tissue to blood and the quantitative role of macrophage-mediated and ciliated clearance mechanisms. The updated BaP model provides very good prediction of the urinary 3-OH BaP concentrations and the relative difference between measured 3-OH BaP in nonsmokers versus smokers. This PBPK model for inhaled BaP is a preliminary tool for quantifying lung BaP dosimetry in rat and humans and was used to prioritize data needs that would provide significant model refinement and robust internal dosimetry capabilities. PMID:27569524

  9. Probabilistic modeling of short survivability in patients with brain metastasis from lung cancer.

    PubMed

    Makond, Bunjira; Wang, Kung-Jeng; Wang, Kung-Min

    2015-05-01

    The prediction of substantially short survivability in patients is extremely risky. In this study, we proposed a probabilistic model using Bayesian network (BN) to predict the short survivability of patients with brain metastasis from lung cancer. A nationwide cancer patient database from 1996 to 2010 in Taiwan was used. The cohort consisted of 438 patients with brain metastasis from lung cancer. We utilized synthetic minority over-sampling technique (SMOTE) to solve the imbalanced property embedded in the problem. The proposed BN was compared with three competitive models, namely, naive Bayes (NB), logistic regression (LR), and support vector machine (SVM). Statistical analysis showed that performances of BN, LR, NB, and SVM were statistically the same in terms of all indices with low sensitivity when these models were applied on an imbalanced data set. Results also showed that SMOTE can improve the performance of the four models in terms of sensitivity, while keeping high accuracy and specificity. Further, the proposed BN is more effective as compared with NB, LR, and SVM from two perspectives: the transparency and ability to show the relation of factors affecting brain metastasis from lung cancer; it allows decision makers to find the probability despite incomplete evidence and information; and the sensitivity of the proposed BN is the highest among all standard machine learning methods. PMID:25804445

  10. A micromechanical model for estimating alveolar wall strain in mechanically ventilated edematous lungs.

    PubMed

    Chen, Zheng-long; Chen, Ya-zhu; Hu, Zhao-yan

    2014-09-15

    To elucidate the micromechanics of pulmonary edema has been a significant medical concern, which is beneficial to better guide ventilator settings in clinical practice. In this paper, we present an adjoining two-alveoli model to quantitatively estimate strain and stress of alveolar walls in mechanically ventilated edematous lungs. The model takes into account the geometry of the alveolus, the effect of surface tension, the length-tension properties of parenchyma tissue, and the change in thickness of the alveolar wall. On the one hand, our model supports experimental findings (Perlman CE, Lederer DJ, Bhattacharya J. Am J Respir Cell Mol Biol 44: 34-39, 2011) that the presence of a liquid-filled alveolus protrudes into the neighboring air-filled alveolus with the shared septal strain amounting to a maximum value of 1.374 (corresponding to the maximum stress of 5.12 kPa) even at functional residual capacity; on the other hand, it further shows that the pattern of alveolar expansion appears heterogeneous or homogeneous, strongly depending on differences in air-liquid interface tension on alveolar segments. The proposed model is a preliminary step toward picturing a global topographical distribution of stress and strain on the scale of the lung as a whole to prevent ventilator-induced lung injury. PMID:24947025

  11. Tubal Ligation Induces Quiescence in the Epithelia of the Fallopian Tube Fimbria.

    PubMed

    Tiourin, Ekaterina; Velasco, Victor S; Rosales, Miguel A; Sullivan, Peggy S; Janzen, Deanna M; Memarzadeh, Sanaz

    2015-10-01

    Tubal ligation keeps the fimbriated end of the fallopian tube intact while interrupting the conduit for sperm and egg between the uterus and ovary. Tubal ligation is associated with an approximately 20% decreased risk of high-grade serous ovarian cancers, which mounting evidence suggests arise from the distal fallopian tube epithelium. We postulated that biological changes at the epithelial cellular level of the distal fallopian tube may account for the surgical procedure's observed risk reduction. We compared the histology, presence of epithelial progenitors (basally located CD44-positive cells), and degree of epithelial proliferation (Ki67-positive cells) of distal fallopian tube from 10 patients with previous tubal ligation and 10 age-matched patients with uncut fallopian tubes. A significantly reduced population of proliferating epithelial progenitors (basally located CD44/Ki67 dual-positive cells) was detected in the tubal ligated specimens (P = .0002). To functionally assess the effect of tubal ligation, a murine model was utilized to compare the growth capacity of distal fallopian tube epithelial cells isolated from either ligated or sham-operated tubal epithelia. Murine fallopian tube epithelial cells isolated after tubal ligation showed a significantly reduced capacity to grow organoids in culture compared to sham-operated controls (P = .002). The findings of this study show that tubal ligation is associated with a reduced presence and decreased proliferation of progenitor cells in the distal fallopian tube epithelium. These compositional and functional changes suggest that tubal ligation induces quiescence of distal fallopian tube epithelial cells. PMID:25736327

  12. Testosterone upregulates anion secretion across porcine vas deferens epithelia in vitro.

    PubMed

    Pierucci-Alves, Fernando; Duncan, Cameron L; Schultz, Bruce D

    2009-10-01

    Testosterone induces and maintains prostaglandin endoperoxide synthase 2 (PTGS2, also known as cyclooxygenase 2) expression in vas deferens epithelial cells, but it remains unknown whether this has a physiological role in the context of male reproductive biology. Prostaglandins induce concentration-dependent increases in anion secretion in porcine vas deferens epithelial cell (1 degrees PVD) monolayers, where bicarbonate contributes to cAMP-stimulated anion secretion. Moreover, bradykinin induces anion secretion across 1 degrees PVD monolayers that is indomethacin sensitive, and both PTGS2 and PTGS1 are expressed in this model system. Therefore, it was hypothesized that testosterone modulates anion secretion across vas deferens epithelia via PTGS-dependent pathways and prostaglandin synthesis. Porcine vas deferens epithelial cells were isolated and cultured as monolayers on permeable supports until assayed in modified Ussing chambers. RNA and protein were isolated concurrently for semiquantitative expression analysis. Testosterone upregulated basal and bradykinin-induced short-circuit current across 1 degrees PVD monolayers, indicative of anion secretion. Testosterone also induced greater transepithelial electrical resistance. Increases in anion secretion were associated with preferential upregulation of PTGS2 at the mRNA and protein levels. In addition, testosterone induced greater basal and bradykinin-induced anion secretion across vas deferens epithelial cells isolated from the distal segment of the duct. Taken together, these results suggest that testosterone upregulates epithelial responsiveness to acute modulations of anion secretion (likely bicarbonate secretion), which ultimately modifies the environment to which sperm are exposed. PMID:19474062

  13. Titanium dioxide nanoparticle impact and translocation through ex vivo, in vivo and in vitro gut epithelia

    PubMed Central

    2014-01-01

    Background TiO2 particles are commonly used as dietary supplements and may contain up to 36% of nano-sized particles (TiO2-NPs). Still impact and translocation of NPs through the gut epithelium is poorly documented. Results We show that, in vivo and ex vivo, agglomerates of TiO2-NPs cross both the regular ileum epithelium and the follicle-associated epithelium (FAE) and alter the paracellular permeability of the ileum and colon epithelia. In vitro, they accumulate in M-cells and mucus-secreting cells, much less in enterocytes. They do not cause overt cytotoxicity or apoptosis. They translocate through a model of FAE only, but induce tight junctions remodeling in the regular ileum epithelium, which is a sign of integrity alteration and suggests paracellular passage of NPs. Finally we prove that TiO2-NPs do not dissolve when sequestered up to 24 h in gut cells. Conclusions Taken together these data prove that TiO2-NPs would possibly translocate through both the regular epithelium lining the ileum and through Peyer’s patches, would induce epithelium impairment, and would persist in gut cells where they would possibly induce chronic damage. PMID:24666995

  14. Antifibrotic and anti-inflammatory activity of the tyrosine kinase inhibitor nintedanib in experimental models of lung fibrosis.

    PubMed

    Wollin, Lutz; Maillet, Isabelle; Quesniaux, Valérie; Holweg, Alexander; Ryffel, Bernhard

    2014-05-01

    The tyrosine kinase inhibitor nintedanib (BIBF 1120) is in clinical development for the treatment of idiopathic pulmonary fibrosis. To explore its mode of action, nintedanib was tested in human lung fibroblasts and mouse models of lung fibrosis. Human lung fibroblasts expressing platelet-derived growth factor (PDGF) receptor-α and -β were stimulated with platelet-derived growth factor BB (homodimer) (PDGF-BB). Receptor activation was assessed by autophosphorylation and cell proliferation by bromodeoxyuridine incorporation. Transforming growth factor β (TGFβ)-induced fibroblast to myofibroblast transformation was determined by α-smooth muscle actin (αSMA) mRNA analysis. Lung fibrosis was induced in mice by intratracheal bleomycin or silica particle administration. Nintedanib was administered every day by gavage at 30, 60, or 100 mg/kg. Preventive nintedanib treatment regimen started on the day that bleomycin was administered. Therapeutic treatment regimen started at various times after the induction of lung fibrosis. Bleomycin caused increased macrophages and lymphocytes in the bronchoalveolar lavage (BAL) and elevated interleukin-1β (IL-1β), tissue inhibitor of metalloproteinase-1 (TIMP-1), and collagen in lung tissue. Histology revealed chronic inflammation and fibrosis. Silica-induced lung pathology additionally showed elevated BAL neutrophils, keratinocyte chemoattractant (KC) levels, and granuloma formation. Nintedanib inhibited PDGF receptor activation, fibroblast proliferation, and fibroblast to myofibroblast transformation. Nintedanib significantly reduced BAL lymphocytes and neutrophils but not macrophages. Furthermore, interleukin-1β, KC, TIMP-1, and lung collagen were significantly reduced. Histologic analysis showed significantly diminished lung inflammation, granuloma formation, and fibrosis. The therapeutic effect was dependent on treatment start and duration. Nintedanib inhibited receptor tyrosine kinase activation and the proliferation and

  15. Numerical Simulations of High-Frequency Respiratory Flows in 2D and 3D Lung Bifurcation Models

    NASA Astrophysics Data System (ADS)

    Chen, Zixi; Parameswaran, Shamini; Hu, Yingying; He, Zhaoming; Raj, Rishi; Parameswaran, Siva

    2014-07-01

    To better understand the human pulmonary system and optimize the high-frequency oscillatory ventilation (HFOV) design, numerical simulations were conducted under normal breathing frequency and HFOV condition using a CFD code Ansys Fluent and its user-defined C programs. 2D and 3D double bifurcating lung models were created, and the geometry corresponds to fifth to seventh generations of airways with the dimensions based on the Weibel's pulmonary model. Computations were carried out for different Reynolds numbers (Re = 400 and 1000) and Womersley numbers (α = 4 and 16) to study the air flow fields, gas transportation, and wall shear stresses in the lung airways. Flow structure was compared with experimental results. Both 2D and 3D numerical models successfully reproduced many results observed in the experiment. The oxygen concentration distribution in the lung model was investigated to analyze the influence of flow oscillation on gas transport inside the lung model.

  16. Efficacy and safety of mesenchymal stromal cells in preclinical models of acute lung injury: a systematic review protocol

    PubMed Central

    2014-01-01

    Background Acute respiratory distress syndrome (ARDS) in humans is caused by an unchecked proinflammatory response that results in diffuse and severe lung injury, and it is associated with a mortality rate of 35 to 45%. Mesenchymal stromal cells (MSCs; ‘adult stem cells’) could represent a promising new therapy for this syndrome, since preclinical evidence suggests that MSCs may ameliorate lung injury. Prior to a human clinical trial, our aim is to conduct a systematic review to compare the efficacy and safety of MSC therapy versus controls in preclinical models of acute lung injury that mimic some aspects of the human ARDS. Methods/Design We will include comparative preclinical studies (randomized and non-randomized) of acute lung injury in which MSCs were administered and outcomes compared to animals given a vehicle control. The primary outcome will be death. Secondary outcomes will include the four key features of preclinical acute lung injury as defined by the American Thoracic Society consensus conference (histologic evidence of lung injury, altered alveolar capillary barrier, lung inflammatory response, and physiological dysfunction) and pathogen clearance for acute lung injury models that are caused by infection. Electronic searches of MEDLINE, Embase, BIOSIS Previews, and Web of Science will be constructed and reviewed by the Peer Review of Electronic Search Strategies (PRESS) process. Search results will be screened independently and in duplicate. Data from eligible studies will be extracted, pooled, and analyzed using random effects models. Risk of bias will be assessed using the Cochrane risk of bias tool, and individual study reporting will be assessed according to the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. Discussion The results of this systematic review will comprehensively summarize the safety and efficacy of MSC therapy in preclinical models of acute lung injury. Our results will help translational scientists and

  17. Environmentally determined differences in the murine lung microbiota and their relation to alveolar architecture.

    PubMed

    Yun, Yeojun; Srinivas, Girish; Kuenzel, Sven; Linnenbrink, Miriam; Alnahas, Safa; Bruce, Kenneth D; Steinhoff, Ulrich; Baines, John F; Schaible, Ulrich E

    2014-01-01

    Commensal bacteria control the micro-ecology of metazoan epithelial surfaces with pivotal effect on tissue homeostasis and host defense. In contrast to the upper respiratory tract, the lower respiratory tract of healthy individuals has largely been considered free of microorganisms. To understand airway micro-ecology we studied microbiota of sterilely excised lungs from mice of different origin including outbred wild mice caught in the natural environment or kept under non-specific-pathogen-free (SPF) conditions as well as inbred mice maintained in non-SPF, SPF or germ-free (GF) facilities. High-throughput pyrosequencing of reverse transcribed 16S rRNA revealed metabolically active murine lung microbiota in all but GF mice. The overall composition across samples was similar at the phylum and family level. However, species richness was significantly different between lung microbiota from SPF and non-SPF mice. Non-cultivatable Betaproteobacteria such as Ralstonia spp. made up the major constituents and were also confirmed by 16S rRNA gene cloning analysis. Additionally, Pasteurellaceae, Enterobacteria and Firmicutes were isolated from lungs of non-SPF mice. Bacterial communities were detectable by fluorescent in situ hybridization (FISH) at alveolar epithelia in the absence of inflammation. Notably, higher bacterial abundance in non-SPF mice correlated with more and smaller size alveolae, which was corroborated by transplanting Lactobacillus spp. lung isolates into GF mice. Our data indicate a common microbial composition of murine lungs, which is diversified through different environmental conditions and affects lung architecture. Identification of the microbiota of murine lungs will pave the path to study their influence on pulmonary immunity to infection and allergens using mouse models. PMID:25470730

  18. Evaluation of a novel tracking system in a breathing lung model.

    PubMed

    O'Donoghue, Kilian; Corvo, Alberto; Nardelli, Pietro; O'Shea, Conor; Khan, Kashif Ali; Kennedy, Marcus; Cantillon-Murphy, Padraig

    2014-01-01

    We present the evaluation of an electromagnetic position tracking system for use with virtual bronchoscopy systems. Our system utilises a planar magnetic coil array and commercially available search coil sensors. Experimental results show the EM tracking accuracy to be in the range of 11.5mm, which is comparable to both commercial and research systems. The use of a bench-top breathing lung model is used to verify system operation in the in vitro setting. A novel fiducial-free registration method is implemented to reduce errors resulting from inaccurate landmark identification commonly associated with point-based registration. After registration, there is good agreement between the measured position of the sensor probe during endoscopic navigation and the lung airways as visualised in a 3D model of the phantom. PMID:25570880

  19. Modelling of peak-flow wall shear stress in major airways of the lung.

    PubMed

    Green, A S

    2004-05-01

    Some respiratory diseases result in the inflammation of the lung airway epithelium. An associated chronic cough, as found in many cases of asthma and in long-term smokers, can exacerbate damage to the epithelial layer. It has been proposed that wall shear stresses, created by peak expiratory flow-rates during a coughing episode, are responsible. The work here uses a computational fluid dynamics technique to model peak expiratory flow in the trachea and major lung bronchi. Calculated wall shear stress values are compared to a limited set of published measurements taken from a physical model. The measurements are discussed in the context of a flow study of a complex bronchial network. A more complete picture is achieved by the calculation method, indicating, in some cases, higher maximum wall shear stresses than measured, confirming the original findings of the experimental work. Recommendations are made as to where further work would be beneficial to medical applications. PMID:15046995

  20. Corneodesmosin, a corneodesmosome-specific basic protein, is expressed in the cornified epithelia of the pig, guinea pig, rat, and mouse.

    PubMed

    Montézin, M; Simon, M; Guerrin, M; Serre, G

    1997-02-25

    Proteolysis of corneodesmosin, a 52- to 56-kDa basic protein located in the extracellular part of the modified desmosomes (corneodesmosomes) of human cornified epithelia, is thought to be a key event of desquamation. Three monoclonal antibodies specific for human corneodesmosin were used to search for the expression of the protein in other mammals. Cryosections of pig, guinea pig, rat, and mouse cornified tissues and proteins sequentially extracted from the corresponding epithelia were analyzed by immunofluorescence and immunoblotting, respectively. Two of the antibodies (F28-27 and B17-21) showed, on the epidermis of the four species and on the cornified epithelia of the rat tongue and esophagus, the same labeling as on human epidermis. Cytoplasmic in the lower granular layer, then pericellular microgranular, the labeling progressively disappeared in the lower cornified layer. By contrast, it persisted up to the surface in the rat tail epidermis. The two antibodies immunodetected basic proteins extracted with isotonic buffer from the epidermis of the pig (50 kDa), guinea pig (52 kDa), and mouse (75 kDa) and from the cornified epithelia of the rat (75 kDa). Immunoreactive proteins of lower Mr were also extracted partly with urea and partly with a reducing agent. The third antibody (G36-19) presented the same reactivities except on murine tissues, where it was unreactive. Our results show that the location, the biochemical characteristics, and the processing of corneodesmosin are similar in five mammals, including humans, suggesting an important role for this protein. They open the way to studies of its function in desquamation using various animal models. PMID:9056420

  1. A new experimental model of acid- and endotoxin-induced acute lung injury in rats.

    PubMed

    Puig, F; Herrero, R; Guillamat-Prats, R; Gómez, M N; Tijero, J; Chimenti, L; Stelmakh, O; Blanch, L; Serrano-Mollar, A; Matthay, M A; Artigas, A

    2016-08-01

    The majority of the animal models of acute lung injury (ALI) are focused on the acute phase. This limits the studies of the mechanisms involved in later phases and the effects of long-term treatments. Thus the goal of this study was to develop an experimental ALI model of aspiration pneumonia, in which diffuse alveolar damage continues for 72 h. Rats were intratracheally instilled with one dose of HCl (0.1 mol/l) followed by another instillation of one dose of LPS (0, 10, 20, 30, or 40 μg/g body weight) 2 h later, which models aspiration of gastric contents that progresses to secondary lung injury from bacteria or bacterial products. The rats were euthanized at 24, 48, and 72 h after the last instillation. The results showed that HCl and LPS at all doses caused activation of inflammatory responses, increased protein permeability and apoptosis, and induced mild hypoxemia in rat lungs at 24 h postinstillation. However, this lung damage was present at 72 h only in rats receiving HCl and LPS at the doses of 30 and 40 μg/g body wt. Mortality (∼50%) occurred in the first 48 h and only in the rats treated with HCl and LPS at the highest dose (40 μg/g body wt). In conclusion, intratracheal instillation of HCl followed by LPS at the dose of 30 μg/g body wt results in severe diffuse alveolar damage that continues at least 72 h. This rat model of aspiration pneumonia-induced ALI will be useful for testing long-term effects of new therapeutic strategies in ALI. PMID:27317688

  2. In Vivo Evaluation of Lung Microwave Ablation in a Porcine Tumor Mimic Model

    SciTech Connect

    Planche, Olivier; Teriitehau, Christophe; Boudabous, Sana; Robinson, Joey Marie; Rao, Pramod; Deschamps, Frederic; Farouil, Geoffroy; Baere, Thierry de

    2013-02-15

    To evaluate the microwave ablation of created tumor mimics in the lung of a large animal model (pigs), with examination of the ablative synergy of multiple antennas. Fifty-six tumor-mimic models of various sizes were created in 15 pigs by using barium-enriched minced collected thigh muscle injected into the lung of the same animal. Tumors were ablated under fluoroscopic guidance by single-antenna and multiple-antenna microwaves. Thirty-five tumor models were treated in 11 pigs with a single antenna at 75 W for 15 min, with 15 measuring 20 mm in diameter, 10 measuring 30 mm, and 10 measuring 40 mm. Mean circularity of the single-antenna ablation zones measured 0.64 {+-} 0.12, with a diameter of 35.7 {+-} 8.7 mm along the axis of the antenna and 32.7 {+-} 12.8 mm perpendicular to the feeding point. Multiple-antenna delivery of 75 W for 15 min caused intraprocedural death of 2 animals; modified protocol to 60 W for 10 min resulted in an ablation zone with a diameter of 43.0 {+-} 7.7 along the axis of the antenna and 54.8 {+-} 8.5 mm perpendicular to the feeding point; circularity was 0.70 {+-} 0.10. A single microwave antenna can create ablation zones large enough to cover lung tumor mimic models of {<=}4 cm with no heat sink effect from vessels of {<=}6 mm. Synergic use of 3 antennas allows ablation of larger volumes than single-antenna or radiofrequency ablation, but great caution must be taken when 3 antennas are used simultaneously in the lung in clinical practice.

  3. A Nonhuman Primate Model of Lung Regeneration: Detergent-Mediated Decellularization and Initial In Vitro Recellularization with Mesenchymal Stem Cells

    PubMed Central

    Bonvillain, Ryan W.; Danchuk, Svitlana; Sullivan, Deborah E.; Betancourt, Aline M.; Semon, Julie A.; Eagle, Michelle E.; Mayeux, Jacques P.; Gregory, Ashley N.; Wang, Guangdi; Townley, Ian K.; Borg, Zachary D.; Weiss, Daniel J.

    2012-01-01

    Currently, patients with end-stage lung disease are limited to lung transplantation as their only treatment option. Unfortunately, the lungs available for transplantation are few. Moreover, transplant recipients require life-long immune suppression to tolerate the transplanted lung. A promising alternative therapeutic strategy is decellularization of whole lungs, which permits the isolation of an intact scaffold comprised of innate extracellular matrix (ECM) that can theoretically be recellularized with autologous stem or progenitor cells to yield a functional lung. Nonhuman primates (NHP) provide a highly relevant preclinical model with which to assess the feasibility of recellularized lung scaffolds for human lung transplantation. Our laboratory has successfully accomplished lung decellularization and initial stem cell inoculation of the resulting ECM scaffold in an NHP model. Decellularization of normal adult rhesus macaque lungs as well as the biology of the resulting acellular matrix have been extensively characterized. Acellular NHP matrices retained the anatomical and ultrastructural properties of native lungs with minimal effect on the content, organization, and appearance of ECM components, including collagen types I and IV, laminin, fibronectin, and sulfated glycosaminoglycans (GAG), due to decellularization. Proteomics analysis showed enrichment of ECM proteins in total tissue extracts due to the removal of cells and cellular proteins by decellularization. Cellular DNA was effectively removed after decellularization (∼92% reduction), and the remaining nuclear material was found to be highly disorganized, very-low-molecular-weight fragments. Both bone marrow- and adipose-derived mesenchymal stem cells (MSC) attach to the decellularized lung matrix and can be maintained within this environment in vitro, suggesting that these cells may be promising candidates and useful tools for lung regeneration. Analysis of decellularized lung slice cultures to which

  4. Cellular targets of estrogen signaling in regeneration of inner ear sensory epithelia

    PubMed Central

    McCullar, Jennifer S.; Oesterle, Elizabeth C.

    2010-01-01

    Estrogen signaling in auditory and vestibular sensory epithelia is a newly emerging focus propelled by the role of estrogen signaling in many other proliferative systems. Understanding the pathways with which estrogen interacts can provide a means to identify how estrogen may modulate proliferative signaling in inner ear sensory epithelia. Reviewed herein are two signaling families, EGF and TGFβ. Both pathways are involved in regulating proliferation of supporting cells in mature vestibular sensory epithelia and have well characterized interactions with estrogen signaling in other systems. It is becoming increasingly clear that elucidating the complexity of signaling in regeneration will be necessary for development of therapeutics that can initiate regeneration and prevent progression to a pathogenic state. PMID:19450430

  5. Ablation of Coactivator Med1 Switches the Cell Fate of Dental Epithelia to That Generating Hair

    PubMed Central

    Nguyen, Thai; Sakai, Kiyoshi; He, Bing; Fong, Chak; Oda, Yuko

    2014-01-01

    Cell fates are determined by specific transcriptional programs. Here we provide evidence that the transcriptional coactivator, Mediator 1 (Med1), is essential for the cell fate determination of ectodermal epithelia. Conditional deletion of Med1 in vivo converted dental epithelia into epidermal epithelia, causing defects in enamel organ development while promoting hair formation in the incisors. We identified multiple processes by which hairs are generated in Med1 deficient incisors: 1) dental epithelial stem cells lacking Med 1 fail to commit to the dental lineage, 2) Sox2-expressing stem cells extend into the differentiation zone and remain multi-potent due to reduced Notch1 signaling, and 3) epidermal fate is induced by calcium as demonstrated in dental epithelial cell cultures. These results demonstrate that Med1 is a master regulator in adult stem cells to govern epithelial cell fate. PMID:24949995

  6. Loss of TGFβ Signaling Destabilizes Homeostasis and Promotes Squamous Cell Carcinomas in Stratified Epithelia

    PubMed Central

    Guasch, Géraldine; Schober, Markus; Pasolli, H. Amalia; Conn, Emily Belmont; Polak, Lisa; Fuchs, Elaine

    2008-01-01

    SUMMARY Although TGFβ is a potent inhibitor of proliferation, epithelia lacking the essential receptor (TβRII) for TGFβ signaling display normal tissue homeostasis. By studying asymptomatic TβRII-deficient stratified epithelia, we show that tissue homeostasis is maintained by balancing hyperproliferation with elevated apoptosis. Moreover, rectal and genital epithelia, which are naturally proliferative, develop spontaneous squamous cell carcinomas with age when TβRII is absent. This progression is associated with a reduction in apoptosis and can be accelerated in phenotypically normal epidermis by oncogenic mutations in Ras. We show that TβRII deficiency leads to enhanced keratinocyte motility and integrin-FAK-Src signaling. Together, these mechanisms provide a molecular framework to account for many of the characteristics of TβRII-deficient invasive SQCCs. PMID:17936557

  7. Enhanced cough reflex in a model of bleomycin-induced lung fibrosis in guinea pigs.

    PubMed

    Fernández-Blanco, Joan Antoni; Aguilera, Mònica; Domènech, Anna; Tarrasón, Gema; Prats, Neus; Miralpeix, Montse; De Alba, Jorge

    2015-12-01

    Fibrotic lung diseases, such as idiopathic pulmonary fibrosis, are associated with spontaneous dry cough and hypersensitivity to tussive agents. Understanding the pathophysiology driving enhanced cough may help us to define better therapies for patients. We hypothesized that lung fibrosis induced by intratracheal bleomycin would exacerbate the cough reflex induced by tussive agents in guinea pigs. Disease progression in the lungs was characterized at days 1, 7, 14, 21 and 28 after bleomycin administration. Inflammatory and fibrotic markers, as well as neurotrophin levels, were assessed in bronchoalveolar lavage fluid and/or lung tissue. Cough sensitivity to citric acid, capsaicin and allylisothiocyanate was evaluated in conscious animals at days 14 and 21 after bleomycin administration. Pulmonary lesions evolved from an early inflammatory phase (from day 1 to day 7) to a fibrotic stage (between days 14 and 28). Fibrosis was related to increased levels of matrix metalloproteinase-2 in bronchoalveolar lavage fluid (day 21: saline, 0.26 ng/ml; bleomycin, 0.49 ng/ml). At day 14, we also observed increased cough reflexes to citric acid (163%), capsaicin (125%) and allylisothiocyanate (178%). Cough exacerbation persisted, but at a lower extent, by day 21 for capsaicin (100%) and allylisothiocyanate (54%). Moreover, bronchoalveolar lavage fluid concentrations of brain-derived neurotrophic factor, suggested to induce nerve remodelling in chronic cough, were also enhanced (day 1: saline, 14.21 pg/ml; bleomycin, 30.09 pg/ml). In summary, our model of bleomycin-induced cough exacerbation may be a valuable tool to investigate cough hypersensitivity and develop antitussive therapies for fibrotic lung diseases. PMID:26275723

  8. Bioaerosols in the lungs of subjects with different ages-part 1: deposition modeling

    PubMed Central

    2016-01-01

    Background In this contribution the inhalation and deposition of bioaerosols including particles with various shapes and sizes were investigated for probands with different ages (1, 5, 15 and 20 y). The study should help to increase our knowledge with regard to the behavior of variably shaped and sized particles in lungs being subject to different developmental stages. Methods Simulation of particle transport and deposition in single structures of the respiratory tract was conducted by using a stochastic model of the tracheobronchial tree and well-validated analytical and empirical deposition formulae. Possible effects of particle geometry on deposition were taken into consideration by application of the aerodynamic diameter concept. Age-dependent lung morphometry and breathing parameters were computed by using appropriate scaling factors. Results Theoretical simulations came to the result that bioparticle deposition in infants and children clearly differs from that in adolescents and adults insofar as the amount of deposited mass exhibits a positive correlation with age. Nose breathing results in higher extrathoracic deposition rates than mouth breathing and, as a consequence of that, lower particle amounts are enabled to enter the lung structures after passing the nasal airways. Under sitting breathing conditions highest alveolar deposition rates were calculated for particles adopting aerodynamic diameters of 10 nm and 4 µm, respectively. Conclusions The study comes to the conclusion that bioparticles have a lower chance to reach the alveoli in infants’ and children’s lungs, but show a higher alveolar deposition probability in the lungs of adolescents and adults. Despite of this circumstance also young subjects may increasingly suffer from biogenic particle burden, when they are subject to a long-term exposure to certain bioaerosols. PMID:27386485

  9. Epithelial anion transporter pendrin contributes to inflammatory lung pathology in mouse models of Bordetella pertussis infection.

    PubMed

    Scanlon, Karen M; Gau, Yael; Zhu, Jingsong; Skerry, Ciaran; Wall, Susan M; Soleimani, Manoocher; Carbonetti, Nicholas H

    2014-10-01

    Pertussis disease, characterized by severe and prolonged coughing episodes, can progress to a critical stage with pulmonary inflammation and death in young infants. However, there are currently no effective treatments for pertussis. We previously studied the role of pertussis toxin (PT), an important Bordetella pertussis virulence factor, in lung transcriptional responses to B. pertussis infection in mouse models. One of the genes most highly upregulated in a PT-dependent manner encodes an epithelial transporter of bicarbonate, chloride, and thiocyanate, named pendrin, that contributes to asthma pathology. In this study, we found that pendrin expression is upregulated at both gene and protein levels in the lungs of B. pertussis-infected mice. Pendrin upregulation is associated with PT production by the bacteria and with interleukin-17A (IL-17A) production by the host. B. pertussis-infected pendrin knockout (KO) mice had higher lung bacterial loads than infected pendrin-expressing mice but had significantly reduced levels of lung inflammatory pathology. However, reduced pathology did not correlate with reduced inflammatory cytokine expression. Infected pendrin KO mice had higher levels of inflammatory cytokines and chemokines than infected pendrin-expressing mice, suggesting that these inflammatory mediators are less active in the airways in the absence of pendrin. In addition, treatment of B. pertussis-infected mice with the carbonic anhydrase inhibitor acetazolamide reduced lung inflammatory pathology without affecting pendrin synthesis or bacterial loads. Together these data suggest that PT contributes to pertussis pathology through the upregulation of pendrin, which promotes conditions favoring inflammatory pathology. Therefore, pendrin may represent a novel therapeutic target for treatment of pertussis disease. PMID:25069981

  10. Pulmonary Delivery of Butyrylcholinesterase as a Model Protein to the Lung.

    PubMed

    Rahhal, Tojan B; Fromen, Catherine A; Wilson, Erin M; Kai, Marc P; Shen, Tammy W; Luft, J Christopher; DeSimone, Joseph M

    2016-05-01

    Pulmonary delivery has great potential for delivering biologics to the lung if the challenges of maintaining activity, stability, and ideal aerosol characteristics can be overcome. To study the interactions of a biologic in the lung, we chose butyrylcholinesterase (BuChE) as our model enzyme, which has application for use as a bioscavenger protecting against organophosphate exposure or for use with pseudocholinesterase deficient patients. In mice, orotracheal administration of free BuChE resulted in 72 h detection in the lungs and 48 h in the broncheoalveolar lavage fluid (BALF). Free BuChE administered to the lung of all mouse backgrounds (Nude, C57BL/6, and BALB/c) showed evidence of an acute cytokine (IL-6, TNF-α, MIP2, and KC) and cellular immune response that subsided within 48 h, indicating relatively safe administration of this non-native biologic. We then developed a formulation of BuChE using Particle Replication in Non-Wetting Templates (PRINT). Aerosol characterization demonstrated biologically active BuChE 1 μm cylindrical particles with a mass median aerodynamic diameter of 2.77 μm, indicative of promising airway deposition via dry powder inhalers (DPI). Furthermore, particulate BuChE delivered via dry powder insufflation showed residence time of 48 h in the lungs and BALF. The in vivo residence time, immune response, and safety of particulate BuChE delivered via a pulmonary route, along with the cascade impaction distribution of dry powder PRINT BuChE, showed promise in the ability to deliver active enzymes with ideal deposition characteristics. These findings provide evidence for the feasibility of optimizing the use of BuChE in the clinic; PRINT BuChE particles can be readily formulated for use in DPIs, providing a convenient and effective treatment option. PMID:27012934

  11. Levosimendan Reduces Lung Injury in a Canine Model of Cardiopulmonary Bypass

    PubMed Central

    Feng, Junbo; Liu, Haiyuan; Chen, Jiayi; Wang, Jiyuan; Liu, Zhuang

    2016-01-01

    Background and Objectives To explore the lung-protective effect of levosimendan (LS) during cardiopulmonary bypass in a canine model by determining the wet/dry weight (W/D) ratio of lung tissue, malonaldehyde (MDA) and superoxide dismutase (SOD) concentrations, and performing a histological evaluation. Materials and Methods Thirty-two canines were divided randomly into four groups and underwent a routine aortic cross-clamping cardiopulmonary bypass procedure for 1 h, followed by recovery for 2 h. Animals were handled as follows: group C (means control group), no special treatment after aortic cross clamping; group P (means pulmonary artery perfusion group), pulmonary artery perfusion with cold oxygenated blood after aortic cross clamping; group LSIV (means intravenous injection of LS group), intravenous injection of LS (65 µg/kg) before thoracotomy, and the rest of the procedure was identical to the control group; group LPS (means pulmonary perfusion with LS group), pulmonary perfusion with cold oxygenated blood combined with LS (65 µg/kg) after aortic cross clamping. Lung tissues were removed and subjected to evaluation of pathological alterations, W/D ratio and MDA and SOD concentrations. Results In group C, the W/D ratio and MDA concentration were higher, while the SOD concentrations were lower (p<0.05). Compared with groups P and LSIV, the MDA concentration was lower in group LPS, while that of SOD was higher (p<0.05); Light and electron microscopy indicated that LS intervention reduced impairment of lung tissues. Conclusion Our findings suggest that LS plays an important role in protecting lung tissues. PMID:27275177

  12. Modeling Lung Carcinogenesis in Radon-Exposed Miner Cohorts: Accounting for Missing Information on Smoking.

    PubMed

    van Dillen, Teun; Dekkers, Fieke; Bijwaard, Harmen; Brüske, Irene; Wichmann, H-Erich; Kreuzer, Michaela; Grosche, Bernd

    2016-05-01

    Epidemiological miner cohort data used to estimate lung cancer risks related to occupational radon exposure often lack cohort-wide information on exposure to tobacco smoke, a potential confounder and important effect modifier. We have developed a method to project data on smoking habits from a case-control study onto an entire cohort by means of a Monte Carlo resampling technique. As a proof of principle, this method is tested on a subcohort of 35,084 former uranium miners employed at the WISMUT company (Germany), with 461 lung cancer deaths in the follow-up period 1955-1998. After applying the proposed imputation technique, a biologically-based carcinogenesis model is employed to analyze the cohort's lung cancer mortality data. A sensitivity analysis based on a set of 200 independent projections with subsequent model analyses yields narrow distributions of the free model parameters, indicating that parameter values are relatively stable and independent of individual projections. This technique thus offers a possibility to account for unknown smoking habits, enabling us to unravel risks related to radon, to smoking, and to the combination of both. PMID:27198876

  13. Phosphodiesterase-5 inhibition by sildenafil citrate in a rat model of bleomycin-induced lung fibrosis.

    PubMed

    Yildirim, Alper; Ersoy, Yasemin; Ercan, Feriha; Atukeren, Pinar; Gumustas, Koray; Uslu, Unal; Alican, Inci

    2010-06-01

    Sildenafil, a selective and potent inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase (PDE)5, has a relaxant effect on the smooth muscle cells of the arterioles supplying the human corpus cavernosum acting via nitric oxide (NO)-dependent mechanism. This study aimed to investigate the possible protective effect of sildenafil citrate on the extent of tissue integrity, oxidant-antioxidant status and neutrophil infiltration to the inflamed organ in a rat model of bleomycin-induced lung fibrosis. Lung fibrosis was induced by intratracheal administration of 0.1 ml of bleomycin hydrochloride (5 mg/kg in 0.9% NaCl) under anesthesia to Sprague-Dawley rats (200-250 g; n = 7-8 per group). Control rats received an equal volume of saline intratracheally. In the treatment groups, the rats were treated with either sildenafil citrate (10 mg/kg per day; subcutaneously) or saline for 14 days. Another group of rats were administered subcutaneously with N(G)-nitro-l-arginine methyl ester (l-NAME; 20 mg/kg in 0.9% NaCl) 5 min after sildenafil injections. After decapitation, the lungs were excised and taken for microscopic evaluation or stored for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity, and for the assessment of apoptosis. Trunk blood was collected for the assessment of serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels. In the group with lung fibrosis, the lung tissue was characterized by microscopic lesions, increased lipid peroxidation with a concomitant reduction in GSH content, increased MPO activity and apoptosis. Serum TNF-alpha and IL-1beta levels were higher in the lung fibrosis group compared to control values. Sildenafil reversed tissue MDA levels, MPO activity and serum pro-inflammatory cytokine levels, and preserved GSH content although its effect on the extent of tissue lesion and apoptosis was not statistically significant. Treatment with l-NAME reversed

  14. Multistate Statistical Modeling: A Tool to Build a Lung Cancer Microsimulation Model That Includes Parameter Uncertainty and Patient Heterogeneity.

    PubMed

    Bongers, Mathilda L; de Ruysscher, Dirk; Oberije, Cary; Lambin, Philippe; Uyl-de Groot, Carin A; Coupé, V M H

    2016-01-01

    With the shift toward individualized treatment, cost-effectiveness models need to incorporate patient and tumor characteristics that may be relevant to treatment planning. In this study, we used multistate statistical modeling to inform a microsimulation model for cost-effectiveness analysis of individualized radiotherapy in lung cancer. The model tracks clinical events over time and takes patient and tumor features into account. Four clinical states were included in the model: alive without progression, local recurrence, metastasis, and death. Individual patients were simulated by repeatedly sampling a patient profile, consisting of patient and tumor characteristics. The transitioning of patients between the health states is governed by personalized time-dependent hazard rates, which were obtained from multistate statistical modeling (MSSM). The model simulations for both the individualized and conventional radiotherapy strategies demonstrated internal and external validity. Therefore, MSSM is a useful technique for obtaining the correlated individualized transition rates that are required for the quantification of a microsimulation model. Moreover, we have used the hazard ratios, their 95% confidence intervals, and their covariance to quantify the parameter uncertainty of the model in a correlated way. The obtained model will be used to evaluate the cost-effectiveness of individualized radiotherapy treatment planning, including the uncertainty of input parameters. We discuss the model-building process and the strengths and weaknesses of using MSSM in a microsimulation model for individualized radiotherapy in lung cancer. PMID:25732723

  15. Model of mucociliary clearance in cystic fibrosis lungs.

    PubMed

    Kurbatova, P; Bessonov, N; Volpert, V; Tiddens, H A W M; Cornu, C; Nony, P; Caudri, D

    2015-05-01

    Mucus clearance is a primary innate defense mechanism in the human airways. Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by dehydration of airway surface liquid and impaired mucociliary clearance. As a result, microorganisms are not efficiently removed from the airways, and patients experience chronic pulmonary infections and inflammation. We propose a new physiologically based mathematical model of muco-ciliary transport consisting of the two major components of the mucociliary clearance system: (i) periciliary liquid layer (PCL) and (ii) mucus layer. We study mucus clearance under normal conditions and in CF patients. Restoring impaired clearance of airway secretions in one of the major goals of therapy in patients with CF. We consider the action of the aerosolized and inhaled medication dornase alfa, which reduces the viscosity of cystic fibrosis mucus, by selectively cleaving the long DNA strands it contains. The results of the model simulations stress the potential relevance of the location of the drug deposition in the central or peripheral airways. Mucus clearance was increased in case the drug was primarily deposited peripherally, i.e. in the small airways. PMID:25746843

  16. The role of placenta growth factor in the hyperoxia-induced acute lung injury in an animal model.

    PubMed

    Zhang, Liang; Yuan, Li-Jie; Zhao, Shuang; Shan, Yu; Wu, Hong-Min; Xue, Xin-Dong

    2015-01-01

    Prolonged exposure to hyperoxia leads to acute lung injury. Alveolar type II cells are main target of hyperoxia-induced lung injury. However, the cellular and molecular mechanisms remain unknown. Here, we aimed to investigate the role of placental growth factor (PLGF) in hyperoxia-induced lung injury. Using experimental hyperoxia-induced lung injury model of neonatal rat and mouse lung epithelial type II cells (MLE-12), we examined the levels of PLGF in bronchoalveolar lavage fluid and in the supernatants of MLE-12 cells. Our results revealed that exogenous PLGF induced hyperoxia-induced lung injury. Furthermore, PLGF triggered a shift of vinculin from insoluble to soluble cell fraction, similar to the observation under hyperoxia stimulation. Moreover, we observed significantly reduced phosphorylation of focal adhesion kinase and increased permeability in MLE-12 cells treated with PLGF. These results suggest that PLGF triggers focal adhesion disassembly in alveolar type II cells via inhibiting the activation of focal adhesion kinase. Our findings reveal a novel role of PLGF in hyperoxia-induced lung injury and provide a potential target for the management of hyperoxia-induced acute lung injury. PMID:25515701

  17. Effect of clay nanoparticles on model lung surfactant: a potential marker of hazard from nanoaerosol inhalation.

    PubMed

    Kondej, Dorota; Sosnowski, Tomasz R

    2016-03-01

    This work investigates influence of different aluminosillicate nanoparticles (NPs) which are found in air in selected workplaces on the properties of the phospholipid (DPPC) monolayer at air-saline interface considered as ex vivo model of the lung surfactant (LS). The measurements were done under physiological-like conditions (deformable liquid interface at 37 °C) for NP concentrations matching the calculated lung doses after exposure in the working environment. Measured surface pressure-area (π-A) isotherms and compressibility curves demonstrated NP-induced changes in the structure and mechanical properties of the lipid monolayer. It was shown that hydrophilic nanomaterials (halloysite and bentonite) induced concentration-dependent impairment of DPPC's ability of attaining high surface pressures on interfacial compression, suggesting a possibility of reduction of physiological function of natural LS. Hydrophobic montmorillonites affected DPPC monolayer in the opposite way; however, they significantly changed the mechanical properties of the air-liquid interface during compression. The results support the hypothesis of possible reduction or even degradation of the natural function of the lung surfactant induced by particle-phospholipid interactions after inhalation of nanoclays. Presented data do not only supplement the earlier results obtained with another LS model (animal-derived surfactant in oscillating bubble experiments) but also offer an explanation of physicochemical mechanisms responsible for detrimental effects which arise after deposition of inhaled nanomaterials on the surface of the respiratory system. PMID:26527341

  18. A Lagrangian Approach for Calculating Microsphere Deposition in a One-Dimensional Lung-Airway Model.

    PubMed

    Vaish, Mayank; Kleinstreuer, Clement

    2015-09-01

    Using the open-source software openfoam as the solver, a novel approach to calculate microsphere transport and deposition in a 1D human lung-equivalent trumpet model (TM) is presented. Specifically, for particle deposition in a nonlinear trumpetlike configuration a new radial force has been developed which, along with the regular drag force, generates particle trajectories toward the wall. The new semi-empirical force is a function of any given inlet volumetric flow rate, micron-particle diameter, and lung volume. Particle-deposition fractions (DFs) in the size range from 2 μm to 10 μm are in agreement with experimental datasets for different laminar and turbulent inhalation flow rates as well as total volumes. Typical run times on a single processor workstation to obtain actual total deposition results at comparable accuracy are 200 times less than that for an idealized whole-lung geometry (i.e., a 3D-1D model with airways up to 23rd generation in single-path only). PMID:26141916

  19. Functional Invariant NKT Cells in Pig Lungs Regulate the Airway Hyperreactivity: A Potential Animal Model

    PubMed Central

    Manickam, Cordelia; Khatri, Mahesh; Rauf, Abdul; Li, Xiangming; Tsuji, Moriya; Rajashekara, Gireesh; Dwivedi, Varun

    2015-01-01

    Important roles played by invariant natural killer T (iNKT) cells in asthma pathogenesis have been demonstrated. We identified functional iNKT cells and CD1d molecules in pig lungs. Pig iNKT cells cultured in the presence of α-GalCer proliferated and secreted Th1 and Th2 cytokines. Like in other animal models, direct activation of pig lung iNKT cells using α-GalCer resulted in acute airway hyperreactivity (AHR). Clinically, acute AHR-induced pigs had increased respiratory rate, enhanced mucus secretion in the airways, fever, etc. In addition, we observed petechial hemorrhages, infiltration of CD4+ cells, and increased Th2 cytokines in AHR-induced pig lungs. Ex vivo proliferated iNKT cells of asthma induced pigs in the presence of C-glycoside analogs of α-GalCer had predominant Th2 phenotype and secreted more of Th2 cytokine, IL-4. Thus, baby pigs may serve as a useful animal model to study iNKT cell-mediated AHR caused by various environmental and microbial CD1d-specific glycolipid antigens. PMID:21042929

  20. Examples of Mesh and NURBS modelling for in vivo lung counting studies.

    PubMed

    Farah, Jad; Broggio, David; Franck, Didier

    2011-03-01

    Realistic calibration coefficients for in vivo counting installations are assessed using voxel phantoms and Monte Carlo calculations. However, voxel phantoms construction is time consuming and their flexibility extremely limited. This paper involves Mesh and non-uniform rational B-splines graphical formats, of greater flexibility, to optimise the calibration of in vivo counting installations. Two studies validating the use of such phantoms and involving geometry deformation and modelling were carried out to study the morphologic effect on lung counting efficiency. The created 3D models fitted with the reference ones, with volumetric differences of <5 %. Moreover, it was found that counting efficiency varies with the inverse of lungs' volume and that the latter primes when compared with chest wall thickness. Finally, a series of different thoracic female phantoms of various cup sizes, chest girths and internal organs' volumes were created starting from the International Commission on Radiological Protection (ICRP) adult female reference computational phantom to give correction factors for the lung monitoring of female workers. PMID:21030397

  1. Ebselen Attenuates Lung Injury in Experimental Model of Carrageenan-Induced Pleurisy in Rats.

    PubMed

    Petronilho, Fabricia; Florentino, Drielly; Silvestre, Fernanda; Danielski, Lucineia Gainski; Nascimento, Diego Zapelini; Vieira, Andriele; Kanis, Luiz Alberto; Fortunato, Jucelia Jeremias; Badawy, Marwa; Barichello, Tatiana; Quevedo, Joao

    2015-08-01

    The study evaluates the role of Ebselen (Eb), an organoselenium compound in animal model of acute lung injury induced by carrageenan (CG). Wistar rats received saline or 2 % λ-carrageenan in the pleural cavity, and treatment with Eb (50 mg/kg intragastrically) or dexamethasone (Dx) (0.5 mg/kg intraperitoneal) after CG administration. After 4 h, rats were euthanized and the pleural exudate removed for analysis of the total cell count, total protein, lactate dehydrogenase, and nitrite/nitrate. Moreover, lung tissue were removed to verify the myeloperoxidase activity and oxidative damage. Eb showed anti-inflammatory activity by inhibiting leukocyte influx, myeloperoxidase activity, and nitrite/nitrate concentration. Eb presented with an anti-inflammatory activity similar to Dx and an antioxidant activity better than Dx. This study suggests that Eb plays an important role against the oxidative damage associated with anti-inflammatory activity in animal model of acute lung injury, proving to be similar or potentially more effective than Dx. PMID:25616904

  2. [Scintigraphic imaging of macrophages involved in lung vasoreflex: rat model].

    PubMed

    Ndoye, O; Mbodj, M; Gassama Seck, S; Sizaret, P Y; Abeille, B; Le Pape, A

    2003-01-01

    At time of pathological situations, a pulmonary fixation of labelled substances injected by intravenous way is observed. This fixation would result from a phagocytosis of these substances by abnormal cells whose presence was induced in the endothelium: Pulmonary Intravascular Macrophages (PIM's). After activation by phagocytosis, these cells are able to secrete powerful vasoactive mediators capable of inducing cardiopulmonary accidents. Hepatic cholestase was induced in Wistar rats by ligation and section of common bile duct. The recruitment of PIM's was followed in vivo by phagocytosis scintigraphic imaging after labelled colloid injection. During the 35 days of evolution of the pathology, we observe a pulmonary fixation of the colloid agents which progresses up to 70% as well as a concomitant decease in the hepatic activity. Histologic examination showed numerous cells related to pulmonary capillaries' endothelium belonging to mononuclear phagocytes line and expressing an activated phenotype of monocytes. The scintigraphic and histological tests carried out enabled us to validate the model of induction of PIM's in rat by ligation of the choledoque one. The study of the vasoactive response via certain mediators can from now be approached, a Doppler technique on the pig aorta is being in the course of evaluation. PMID:15770812

  3. A deformable lung tumor tracking method in fluoroscopic video using active shape models: a feasibility study

    NASA Astrophysics Data System (ADS)

    Xu, Qianyi; Hamilton, Russell J.; Schowengerdt, Robert A.; Jiang, Steve B.

    2007-09-01

    A dynamic multi-leaf collimator (DMLC) can be used to track a moving target during radiotherapy. One of the major benefits for DMLC tumor tracking is that, in addition to the compensation for tumor translational motion, DMLC can also change the aperture shape to conform to a deforming tumor projection in the beam's eye view. This paper presents a method that can track a deforming lung tumor in fluoroscopic video using active shape models (ASM) (Cootes et al 1995 Comput. Vis. Image Underst. 61 38-59). The method was evaluated by comparing tracking results against tumor projection contours manually edited by an expert observer. The evaluation shows the feasibility of using this method for precise tracking of lung tumors with deformation, which is important for DMLC-based real-time tumor tracking.

  4. Application to Rat Lung of the Extended Rorschach-Hazlewood Model of Spin-Lattice Relaxation

    NASA Astrophysics Data System (ADS)

    Hackmann, Andreas; Ailion, David C.; Ganesan, Krishnamurthy; Goodrich, K. Craig; Chen, Songhua; Laicher, Gernot; Cutillo, Antonio G.

    1996-02-01

    The spin-lattice relaxation timeT1was measured in excised degassed (airless) rat lungs over the frequency range 6.7 to 80.5 MHz. The observed frequency dependence was fitted successfully to the water-biopolymer cross-relaxation theory proposed by H. E. Rorschach and C. F. Hazlewood (RH) [J. Magn. Reson.70,79 (1986)]. The rotating frame spin-lattice relaxation timeT1ρwas also measured in rat lung fragments over the frequency range 0.56 to 5.6 kHz, and the observed frequency dependence was explained with an extension of the RH model. The agreement between the theory and the experimental data in both cases is good.

  5. Neutrophil function in a rat model of endotoxin-induced lung injury.

    PubMed

    Simons, R K; Maier, R V; Lennard, E S

    1987-02-01

    Polymorphonuclear neutrophil leukocytes (PMNs) are known to cross the alveolar-capillary barrier and enter the alveolus in acute adult respiratory distress syndrome (ARDS). The pathogenic role of PMNs in both the acute lung injury and subsequent infectious susceptibility in ARDS is not clear. In the present study we investigated the functional status of various neutrophil populations using a chronic, endotoxemia-induced ARDS model. Rats infused with Escherichia coli endotoxin for three days develop an acute lung injury with a histologic picture closely resembling human ARDS. The PMNs recovered from the circulation and by bronchoalveolar lavage were compared with normal rat PMNs. In endotoxemic animals, superoxide production was markedly enhanced in circulating PMNs, indicating production of high levels of potentially cytotoxic oxygen intermediates, while myeloperoxidase activity was decreased in both circulating and lavage PMNs, indicating depressed myeloperoxidase-dependent antimicrobial activity. PMID:3028317

  6. Development of a Multicompartment Permeability-Limited Lung PBPK Model and Its Application in Predicting Pulmonary Pharmacokinetics of Antituberculosis Drugs

    PubMed Central

    Gaohua, L; Wedagedera, J; Small, BG; Almond, L; Romero, K; Hermann, D; Hanna, D; Jamei, M; Gardner, I

    2015-01-01

    Achieving sufficient concentrations of antituberculosis (TB) drugs in pulmonary tissue at the optimum time is still a challenge in developing therapeutic regimens for TB. A physiologically based pharmacokinetic model incorporating a multicompartment permeability-limited lung model was developed and used to simulate plasma and pulmonary concentrations of seven drugs. Passive permeability of drugs within the lung was predicted using an in vitro-in vivo extrapolation approach. Simulated epithelial lining fluid (ELF):plasma concentration ratios showed reasonable agreement with observed clinical data for rifampicin, isoniazid, ethambutol, and erythromycin. For clarithromycin, itraconazole and pyrazinamide the observed ELF:plasma ratios were significantly underpredicted. Sensitivity analyses showed that changing ELF pH or introducing efflux transporter activity between lung tissue and ELF can alter the ELF:plasma concentration ratios. The described model has shown utility in predicting the lung pharmacokinetics of anti-TB drugs and provides a framework for predicting pulmonary concentrations of novel anti-TB drugs. PMID:26535161

  7. A comparison of change point models with application to longitudinal lung function measurements in children with cystic fibrosis.

    PubMed

    Moss, Angela; Juarez-Colunga, E; Nathoo, Farouk; Wagner, Brandie; Sagel, Scott

    2016-05-30

    Cystic fibrosis (CF) is a hereditary lung disease characterized by loss of lung function over time. Lung function in CF is believed to decline at a higher rate during the adolescence period. It has been also hypothesized that there is a subgroup of individuals for whom lung disease remains relatively stable with only a slight decline over their lifetime. Using data from the University of Colorado CF Children's Registry, we investigate four change point models to model the decline of lung function in children and adolescents: (i) a two-component mixture random change point model, (ii) a two-component mixture-fixed change point model, (iii) a random change point model, and (iv) a fixed change point model. The models are investigated through posterior predictive simulation at the individual and population levels, and a simulation study examining the effects of model misspecification. The data support the mixed random change point model as the preferred model, with roughly 30% of adolescents experiencing a steady decline of 0.5 %FEV1 per year and 70% experiencing an increase in decline of 4.4 %FEV1 per year beginning on average at 14.6 years of age. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27118629

  8. Lamb model of respiratory syncytial virus-associated lung disease: insights to pathogenesis and novel treatments.

    PubMed

    Ackermann, Mark R

    2014-01-01

    Preterm birth is a risk factor for respiratory syncytial virus (RSV) bronchiolitis and hospitalization. The pathogenesis underlying this is not fully understood, and in vivo studies are needed to better clarify essential cellular features and molecular mechanisms. Such studies include analysis of lung tissue from affected human infants and various animal models. The preterm and newborn lamb lung has developmental, structural, cellular, physiologic, and immunologic features similar to that of human infants. Also, the lamb lung is susceptible to various strains of RSV that infect infants and cause similar bronchiolar lesions. Studies in lambs suggest that viral replication in airways (especially bronchioles) is extensive by 4 days after infection, along with bronchiolitis characterized by degeneration and necrosis of epithelial cells, syncytial cell formation, neutrophil infiltration, epithelial cell hypertrophy and hyperplasia, and innate and adaptive immune responses. RSV bronchiolitis greatly affects airflow and gaseous exchange. RSV disease severity is increased in preterm lambs compared with full-term lambs; similar to human infants. The lamb is conducive to experimental assessment of novel, mechanistic therapeutic interventions such as delivery of vascular endothelial growth factor and enhancement of airway epithelial oxidative responses, Club (Clara) cell protein 10, and synthesized compounds such as nanobodies. In contrast, exposure of the fetal ovine lung in vivo to ethanol, a risk factor for preterm birth, reduces pulmonary alveolar development and surfactant protein A expression. Because the formalin-inactivated RSV vaccination enhances some inflammatory responses to RSV infection in lambs, this model has the potential to assess mechanisms of formalin-inactivated RSV enhanced disease as well as newly developed vaccines. PMID:24936027

  9. Hyperglycemia impedes lung bacterial clearance in a murine model of cystic fibrosis-related diabetes

    PubMed Central

    Hunt, William R.; Zughaier, Susu M.; Guentert, Dana E.; Shenep, Melissa A.; Koval, Michael; McCarty, Nael A.

    2013-01-01

    Cystic fibrosis-related diabetes (CFRD) is the most common comorbidity associated with cystic fibrosis (CF), impacting more than half of patients over age 30. CFRD is clinically significant, portending accelerated decline in lung function, more frequent pulmonary exacerbations, and increased mortality. Despite the profound morbidity associated with CFRD, little is known about the underlying CFRD-related pulmonary pathology. Our aim was to develop a murine model of CFRD to explore the hypothesis that elevated glucose in CFRD is associated with reduced lung bacterial clearance. A diabetic phenotype was induced in gut-corrected CF transmembrane conductance regulator (CFTR) knockout mice (CFKO) and their CFTR-expressing wild-type littermates (WT) utilizing streptozotocin. Mice were subsequently challenged with an intratracheal inoculation of Pseudomonas aeruginosa (PAO1) (75 μl of 1–5 × 106 cfu/ml) for 18 h. Bronchoalveolar lavage fluid was collected for glucose concentration and cell counts. A portion of the lung was homogenized and cultured as a measure of the remaining viable PAO1 inoculum. Diabetic mice had increased airway glucose compared with nondiabetic mice. The ability to clear bacteria from the lung was significantly reduced in diabetic WT mice and control CFKO mice. Critically, bacterial clearance by diabetic CFKO mice was significantly more diminished compared with nondiabetic CFKO mice, despite an even more robust recruitment of neutrophils to the airways. This finding that CFRD mice boast an exaggerated, but less effective, inflammatory cell response to intratracheal PAO1 challenge presents a novel and useful murine model to help identify therapeutic strategies that promote bacterial clearance in CFRD. PMID:24097557

  10. Hyperglycemia impedes lung bacterial clearance in a murine model of cystic fibrosis-related diabetes.

    PubMed

    Hunt, William R; Zughaier, Susu M; Guentert, Dana E; Shenep, Melissa A; Koval, Michael; McCarty, Nael A; Hansen, Jason M

    2014-01-01

    Cystic fibrosis-related diabetes (CFRD) is the most common comorbidity associated with cystic fibrosis (CF), impacting more than half of patients over age 30. CFRD is clinically significant, portending accelerated decline in lung function, more frequent pulmonary exacerbations, and increased mortality. Despite the profound morbidity associated with CFRD, little is known about the underlying CFRD-related pulmonary pathology. Our aim was to develop a murine model of CFRD to explore the hypothesis that elevated glucose in CFRD is associated with reduced lung bacterial clearance. A diabetic phenotype was induced in gut-corrected CF transmembrane conductance regulator (CFTR) knockout mice (CFKO) and their CFTR-expressing wild-type littermates (WT) utilizing streptozotocin. Mice were subsequently challenged with an intratracheal inoculation of Pseudomonas aeruginosa (PAO1) (75 μl of 1-5 × 10(6) cfu/ml) for 18 h. Bronchoalveolar lavage fluid was collected for glucose concentration and cell counts. A portion of the lung was homogenized and cultured as a measure of the remaining viable PAO1 inoculum. Diabetic mice had increased airway glucose compared with nondiabetic mice. The ability to clear bacteria from the lung was significantly reduced in diabetic WT mice and control CFKO mice. Critically, bacterial clearance by diabetic CFKO mice was significantly more diminished compared with nondiabetic CFKO mice, despite an even more robust recruitment of neutrophils to the airways. This finding that CFRD mice boast an exaggerated, but less effective, inflammatory cell response to intratracheal PAO1 challenge presents a novel and useful murine model to help identify therapeutic strategies that promote bacterial clearance in CFRD. PMID:24097557

  11. Models for comparing lung-cancer risks in radon- and plutonium-exposed experimental animals

    SciTech Connect

    Gilbert, E.S.; Cross, F.T.; Sanders, C.L.; Dagle, G.E.

    1990-10-01

    Epidemiologic studies of radon-exposed underground miners have provided the primary basis for estimating human lung-cancer risks resulting from radon exposure. These studies are sometimes used to estimate lung-cancer risks resulting from exposure to other alpha- emitters as well. The latter use, often referred to as the dosimetric approach, is based on the assumption that a specified dose to the lung produces the same lung-tumor risk regardless of the substance producing the dose. At Pacific Northwest Laboratory, experiments have been conducted in which laboratory rodents have been given inhalation exposures to radon and to plutonium ({sup 239}PuO{sub 2}). These experiments offer a unique opportunity to compare risks, and thus to investigate the validity of the dosimetric approach. This comparison is made most effectively by modeling the age-specific risk as a function of dose in a way that is comparable to analyses of human data. Such modeling requires assumptions about whether tumors are the cause of death or whether they are found incidental to death from other causes. Results based on the assumption that tumors are fatal indicate that the radon and plutonium dose-response curves differ, with a linear function providing a good description of the radon data, and a pure quadratic function providing a good description of the plutonium data. However, results based on the assumption that tumors are incidental to death indicate that the dose-response curves for the two exposures are very similar, and thus support the dosimetric approach. 14 refs., 2 figs., 6 tabs.

  12. Size influences the effect of hydrophobic nanoparticles on lung surfactant model systems.

    PubMed

    Dwivedi, Mridula V; Harishchandra, Rakesh Kumar; Koshkina, Olga; Maskos, Michael; Galla, Hans-Joachim

    2014-01-01

    The alveolar lung surfactant (LS) is a complex lipid protein mixture that forms an interfacial monolayer reducing the surface tension to near zero values and thus preventing the lungs from collapse. Due to the expanding field of nanotechnology and the corresponding unavoidable exposure of human beings from the air, it is crucial to study the potential effects of nanoparticles (NPs) on the structural organization of the lung surfactant system. In the present study, we investigated both, the domain structure in pure DPPC monolayers as well as in lung surfactant model systems. In the pure lipid system we found that two different sized hydrophobic polymeric nanoparticles with diameter of ~12 nm and ~136 nm have contrasting effect on the functional and structural behavior. The small nanoparticles inserted into fluid domains at the LE-LC phase transition are not visibly disturbing the phase transition but disrupting the domain morphology of the LE phase. The large nanoparticles led to an expanded isotherm and to a significant decrease in the line tension and thus to a drastic disruption of the domain structures at a much lower number of nanoparticles with respect to the lipid. The surface activity of the model LS films again showed drastic variations due to presence of different sized NPs illustrated by the film balance isotherms and the atomic force microscopy. AFM revealed laterally profuse multilayer protrusion formation on compression but only in the presence of 136 nm sized nanoparticles. Moreover we investigated the vesicle insertion process into a preformed monolayer. A severe inhibition was observed only in the presence of ~136 nm NPs compared to minor effects in the presence of ~12 nm NPs. Our study clearly shows that the size of the nanoparticles made of the same material determines the interaction with biological membranes. PMID:24411261

  13. Home energy efficiency and radon related risk of lung cancer: modelling study

    PubMed Central

    Milner, James; Shrubsole, Clive; Das, Payel; Jones, Benjamin; Ridley, Ian; Chalabi, Zaid; Hamilton, Ian; Armstrong, Ben; Davies, Michael

    2014-01-01

    Objective To investigate the effect of reducing home ventilation as part of household energy efficiency measures on deaths from radon related lung cancer. Design Modelling study. Setting England. Intervention Home energy efficiency interventions, motivated in part by targets for reducing greenhouse gases, which entail reduction in uncontrolled ventilation in keeping with good practice guidance. Main outcome measures Modelled current and future distributions of indoor radon levels for the English housing stock and associated changes in life years due to lung cancer mortality, estimated using life tables. Results Increasing the air tightness of dwellings (without compensatory purpose-provided ventilation) increased mean indoor radon concentrations by an estimated 56.6%, from 21.2 becquerels per cubic metre (Bq/m3) to 33.2 Bq/m3. After the lag in lung cancer onset, this would result in an additional annual burden of 4700 life years lost and (at peak) 278 deaths. The increases in radon levels for the millions of homes that would contribute most of the additional burden are below the threshold at which radon remediation measures are cost effective. Fitting extraction fans and trickle ventilators to restore ventilation will help offset the additional burden but only if the ventilation related energy efficiency gains are lost. Mechanical ventilation systems with heat recovery may lower radon levels and the risk of cancer while maintaining the advantage of energy efficiency for the most airtight dwellings but there is potential for a major adverse impact on health if such systems fail. Conclusion Unless specific remediation is used, reducing the ventilation of dwellings will improve energy efficiency only at the expense of population wide adverse impact on indoor exposure to radon and risk of lung cancer. The implications of this and other consequences of changes to ventilation need to be carefully evaluated to ensure that the desirable health and environmental benefits of

  14. Respiratory Tract Lung Geometry and Dosimetry Model for Male Sprague-Dawley Rats

    SciTech Connect

    Miller, Frederick J.; Asgharian, Bahman; Schroeter, Jeffry D.; Price, Owen; Corley, Richard A.; Einstein, Daniel R.; Jacob, Rick E.; Cox, Timothy C.; Kabilan, Senthil; Bentley, Timothy

    2015-07-24

    While inhalation toxicological studies of various compounds have been conducted using a number of different strains of rats, mechanistic dosimetry models have only had tracheobronchial (TB) structural data for Long-Evans rats, detailed morphometric data on the alveolar region of Sprague-Dawley rats and limited alveolar data on other strains. Based upon CT imaging data for two male Sprague-Dawley rats, a 15-generation, symmetric typical path model was developed for the TB region. Literature data for the alveolar region of Sprague-Dawley rats were analyzed to develop an eight-generation model, and the two regions were joined to provide a complete lower respiratory tract model for Sprague-Dawley rats. The resulting lung model was used to examine particle deposition in Sprague-Dawley rats and to compare these results with predicted deposition in Long-Evans rats. Relationships of various physiologic variables and lung volumes were either developed in this study or extracted from the literature to provide the necessary input data for examining particle deposition. While the lengths, diameters and branching angles of the TB airways differed between the two Sprague-Dawley rats, the predicted deposition patterns in the three major respiratory tract regions were very similar. Between Sprague-Dawley and Long-Evans rats, significant differences in TB and alveolar predicted deposition fractions were observed over a wide range of particle sizes, with TB deposition fractions being up to 3- to 4-fold greater in Sprague-Dawley rats and alveolar deposition being significantly greater in Long-Evans rats. Thus, strain-specific lung geometry models should be used for particle deposition calculations and interspecies dose comparisons.

  15. Respiratory tract lung geometry and dosimetry model for male Sprague-Dawley rats.

    SciTech Connect

    Miller, Frederick J.; Asgharian, Bahman; Schroeter, Jeffry D.; Price, Owen; Corley, Richard A.; Einstein, Daniel R.; Jacob, Rick E.; Cox, Timothy C.; Kabilan, Senthil; Bentley, Timothy

    2014-08-26

    While inhalation toxicological studies of various compounds have been conducted using a number of different strains of rats, mechanistic dosimetry models have only had tracheobronchial (TB) structural data for Long-Evans rats, detailed morphometric data on the alveolar region of Sprague-Dawley rats and limited alveolar data on other strains. Based upon CT imaging data for two male Sprague-Dawley rats, a 15-generation, symmetric typical path model was developed for the TB region. Literature data for the alveolar region of Sprague-Dawley rats were analyzed to develop an eight-generation model, and the two regions were joined to provide a complete lower respiratory tract model for Sprague-Dawley rats. The resulting lung model was used to examine particle deposition in Sprague-Dawley rats and to compare these results with predicted deposition in Long-Evans rats. Relationships of various physiologic variables and lung volumes were either developed in this study or extracted from the literature to provide the necessary input data for examining particle deposition. While the lengths, diameters and branching angles of the TB airways differed between the two Sprague- Dawley rats, the predicted deposition patterns in the three major respiratory tract regions were very similar. Between Sprague-Dawley and Long-Evans rats, significant differences in TB and alveolar predicted deposition fractions were observed over a wide range of particle sizes, with TB deposition fractions being up to 3- to 4-fold greater in Sprague-Dawley rats and alveolar deposition being significantly greater in Long-Evans rats. Thus, strain-specific lung geometry models should be used for particle deposition calculations and interspecies dose comparisons.

  16. Modeling the effect of refraction on OCT imaging of lung tissue: a ray-tracing approach

    NASA Astrophysics Data System (ADS)

    Golabchi, Fatemeh N.; Golabchi, Ali; Brooks, Dana H.; Gouldstone, Andrew; DiMarzio, Charles A.

    2012-03-01

    Determining the structure of lung tissue is difficult in ex-vivo samples. Optical coherence tomography (OCT) can image alveoli but ignores optical effects that distort the images. For example, light refracts and changes speed at the alveolar air-tissue surface. We employ ray-tracing to model OCT imaging with directional and speed changes included, using spherical shapes in 2D. Results show apparent thickening of inter-aveolar walls and distortion of shape and depth. Our approach suggests a correction algorithm by combining the model with image analysis. Distortion correction will allow inference of tissue mechanical properties and deeper imaging.

  17. Numerical simulation of air flow in a model of lungs with mouth cavity

    NASA Astrophysics Data System (ADS)

    Elcner, Jakub; Lizal, Frantisek; Jedelsky, Jan; Jicha, Miroslav

    2012-04-01

    The air flow in a realistic geometry of human lung is simulated with computational flow dynamics approach as stationary inspiration. Geometry used for the simulation includes oral cavity, larynx, trachea and bronchial tree up to the seventh generation of branching. Unsteady RANS approach was used for the air flow simulation. Velocities corresponding to 15, 30 and 60 litres/min of flow rate were set as boundary conditions at the inlet to the model. These flow rates are frequently used as a representation of typical human activities. Character of air flow in the model for these different flow rates is discussed with respect to future investigation of particle deposition.

  18. Urinary Volatile Compounds as Biomarkers for Lung Cancer: A Proof of Principle Study Using Odor Signatures in Mouse Models of Lung Cancer

    PubMed Central

    Matsumura, Koichi; Opiekun, Maryanne; Oka, Hiroaki; Vachani, Anil; Albelda, Steven M.; Yamazaki, Kunio; Beauchamp, Gary K.

    2010-01-01

    A potential strategy for diagnosing lung cancer, the leading cause of cancer-related death, is to identify metabolic signatures (biomarkers) of the disease. Although data supports the hypothesis that volatile compounds can be detected in the breath of lung cancer patients by the sense of smell or through bioanalytical techniques, analysis of breath samples is cumbersome and technically challenging, thus limiting its applicability. The hypothesis explored here is that variations in small molecular weight volatile organic compounds (“odorants”) in urine could be used as biomarkers for lung cancer. To demonstrate the presence and chemical structures of volatile biomarkers, we studied mouse olfactory-guided behavior and metabolomics of volatile constituents of urine. Sensor mice could be trained to discriminate between odors of mice with and without experimental tumors demonstrating that volatile odorants are sufficient to identify tumor-bearing mice. Consistent with this result, chemical analyses of urinary volatiles demonstrated that the amounts of several compounds were dramatically different between tumor and control mice. Using principal component analysis and supervised machine-learning, we accurately discriminated between tumor and control groups, a result that was cross validated with novel test groups. Although there were shared differences between experimental and control animals in the two tumor models, we also found chemical differences between these models, demonstrating tumor-based specificity. The success of these studies provides a novel proof-of-principle demonstration of lung tumor diagnosis through urinary volatile odorants. This work should provide an impetus for similar searches for volatile diagnostic biomarkers in the urine of human lung cancer patients. PMID:20111698

  19. Hierarchical Bayesian modeling of spatio-temporal patterns of lung cancer incidence risk in Georgia, USA: 2000-2007

    NASA Astrophysics Data System (ADS)

    Yin, Ping; Mu, Lan; Madden, Marguerite; Vena, John E.

    2014-10-01

    Lung cancer is the second most commonly diagnosed cancer in both men and women in Georgia, USA. However, the spatio-temporal patterns of lung cancer risk in Georgia have not been fully studied. Hierarchical Bayesian models are used here to explore the spatio-temporal patterns of lung cancer incidence risk by race and gender in Georgia for the period of 2000-2007. With the census tract level as the spatial scale and the 2-year period aggregation as the temporal scale, we compare a total of seven Bayesian spatio-temporal models including two under a separate modeling framework and five under a joint modeling framework. One joint model outperforms others based on the deviance information criterion. Results show that the northwest region of Georgia has consistently high lung cancer incidence risk for all population groups during the study period. In addition, there are inverse relationships between the socioeconomic status and the lung cancer incidence risk among all Georgian population groups, and the relationships in males are stronger than those in females. By mapping more reliable variations in lung cancer incidence risk at a relatively fine spatio-temporal scale for different Georgian population groups, our study aims to better support healthcare performance assessment, etiological hypothesis generation, and health policy making.

  20. Proteomic Analysis of Lung Tissue in a Rat Acute Lung Injury Model: Identification of PRDX1 as a Promoter of Inflammation

    PubMed Central

    Liu, Dongdong; Mao, Pu; Huang, Yongbo; Liu, Yiting; Liu, Xiaoqing; Pang, Xiaoqing; Li, Yimin

    2014-01-01

    Acute respiratory distress syndrome (ARDS) remains a high morbidity and mortality disease entity in critically ill patients, despite decades of numerous investigations into its pathogenesis. To obtain global protein expression changes in acute lung injury (ALI) lung tissues, we employed a high-throughput proteomics method to identify key components which may be involved in the pathogenesis of ALI. In the present study, we analyzed lung tissue proteomes of Pseudomonas aeruginosa-induced ALI rats and identified eighteen proteins whose expression levels changed more than twofold as compared to normal controls. In particular, we found that PRDX1 expression in culture medium was elevated by a lipopolysaccharide (LPS) challenge in airway epithelial cells in vitro. Furthermore, overexpression of PRDX1 increased the expression of proinflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α), whereas knockdown of PRDX1 led to downregulated expression of cytokines induced by LPS. In conclusion, our findings provide a global alteration in the proteome of lung tissues in the ALI rat model and indicate that PRDX1 may play a critical role in the pathogenesis of ARDS by promoting inflammation and represent a novel strategy for the development of new therapies against ALI. PMID:25024510

  1. Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells

    SciTech Connect

    Person, Rachel J.; Olive Ngalame, Ntube N.; Makia, Ngome L.; Bell, Matthew W.; Waalkes, Michael P.; Tokar, Erik J.

    2015-07-01

    Inorganic arsenic is a human lung carcinogen. We studied the ability of chronic inorganic arsenic (2 μM; as sodium arsenite) exposure to induce a cancer phenotype in the immortalized, non-tumorigenic human lung peripheral epithelial cell line, HPL-1D. After 38 weeks of continuous arsenic exposure, secreted matrix metalloproteinase-2 (MMP2) activity increased to over 200% of control, levels linked to arsenic-induced cancer phenotypes in other cell lines. The invasive capacity of these chronic arsenic-treated lung epithelial (CATLE) cells increased to 320% of control and colony formation increased to 280% of control. CATLE cells showed enhanced proliferation in serum-free media indicative of autonomous growth. Compared to control cells, CATLE cells showed reduced protein expression of the tumor suppressor gene PTEN (decreased to 26% of control) and the putative tumor suppressor gene SLC38A3 (14% of control). Morphological evidence of epithelial-to-mesenchymal transition (EMT) occurred in CATLE cells together with appropriate changes in expression of the EMT markers vimentin (VIM; increased to 300% of control) and e-cadherin (CDH1; decreased to 16% of control). EMT is common in carcinogenic transformation of epithelial cells. CATLE cells showed increased KRAS (291%), ERK1/2 (274%), phosphorylated ERK (p-ERK; 152%), and phosphorylated AKT1 (p-AKT1; 170%) protein expression. Increased transcript expression of metallothioneins, MT1A and MT2A and the stress response genes HMOX1 (690%) and HIF1A (247%) occurred in CATLE cells possibly in adaptation to chronic arsenic exposure. Thus, arsenic induced multiple cancer cell characteristics in human peripheral lung epithelial cells. This model may be useful to assess mechanisms of arsenic-induced lung cancer. - Highlights: • Chronic arsenic exposure transforms a human peripheral lung epithelia cell line. • Cells acquire characteristics in common with human lung adenocarcinoma cells. • These transformed cells provide a

  2. A Comparative Study of Lung Host Defense in Murine Obesity Models. Insights into Neutrophil Function.

    PubMed

    Ubags, Niki D J; Burg, Elianne; Antkowiak, Maryellen; Wallace, Aaron M; Dilli, Estee; Bement, Jenna; Wargo, Matthew J; Poynter, Matthew E; Wouters, Emiel F M; Suratt, Benjamin T

    2016-08-01

    We have shown that obesity-associated attenuation of murine acute lung injury is driven, in part, by blunted neutrophil chemotaxis, yet differences were noted between the two models of obesity studied. We hypothesized that obesity-associated impairment of multiple neutrophil functions contributes to increased risk for respiratory infection but that such impairments may vary between murine models of obesity. We examined the most commonly used murine obesity models (diet-induced obesity, db/db, CPE(fat/fat), and ob/ob) using a Klebsiella pneumoniae pneumonia model and LPS-induced pneumonitis. Marrow-derived neutrophils from uninjured lean and obese mice were examined for in vitro functional responses. All obesity models showed impaired clearance of K. pneumoniae, but in differing temporal patterns. Failure to contain infection in obese mice was seen in the db/db model at both 24 and 48 hours, yet this defect was only evident at 24 hours in CPE(fat/fat) and ob/ob models, and at 48 hours in diet-induced obesity. LPS-induced airspace neutrophilia was decreased in all models, and associated with blood neutropenia in the ob/ob model but with leukocytosis in the others. Obese mouse neutrophils from all models demonstrated impaired chemotaxis, whereas neutrophil granulocyte colony-stimulating factor-mediated survival, LPS-induced cytokine transcription, and mitogen-activated protein kinase and signal transducer and activator of transcription 3 activation in response to LPS and granulocyte colony-stimulating factor, respectively, were variably impaired across the four models. Obesity-associated impairment of host response to lung infection is characterized by defects in neutrophil recruitment and survival. However, critical differences exist between commonly used mouse models of obesity and may reflect variable penetrance of elements of the metabolic syndrome, as well as other factors. PMID:27128821

  3. Potential of in vitro reconstituted 3D human airway epithelia (MucilAir™) to assess respiratory sensitizers.

    PubMed

    Huang, Song; Wiszniewski, Ludovic; Constant, Samuel; Roggen, Erwin

    2013-04-01

    Respiratory sensitizers are considered as substances of higher risk, at the same level as carcinogens, mutagens and toxic chemicals for reproduction. Presently, there is no validated assay for identifying the respiratory sensitizers. Based on a fully differentiated and functional in vitro cell model of the human airway epithelium, MucilAir™, we attempt to develop such assay. To this end, we invented a novel method, using Dextran as carrier, for applying the water insoluble chemicals to the apical surface of the airway epithelia. Using the Dextran carrier method, we successfully tested some reference chemical compounds known to cause respiratory sensitisation in human beings, including MDI, TMA and HCPt. Interestingly, these chemical sensitizers differentially up-regulated the releases of certain cytokines and chemokines involved in allergic responses. We believe that based on MucilAir™ an in vitro assay could be developed for identification and characterization of the respiratory sensitizers. PMID:23089132

  4. Striatins as plaque molecules of zonulae adhaerentes in simple epithelia, of tessellate junctions in stratified epithelia, of cardiac composite junctions and of various size classes of lateral adherens junctions in cultures of epithelia- and carcinoma-derived cells.

    PubMed

    Franke, Werner W; Rickelt, Steffen; Zimbelmann, Ralf; Dörflinger, Yvette; Kuhn, Caecilia; Frey, Norbert; Heid, Hans; Rosin-Arbesfeld, Rina

    2015-03-01

    Proteins of the striatin family (striatins 1-4; sizes ranging from 90 to 110 kDa on SDS-polyacrylamide gel electrophoresis) are highly homologous in their amino acid sequences but can differ in their cell-type-specific gene expression patterns and biological functions. In various cell types, we have found one, two or three polypeptides of this evolutionarily old and nearly ubiquitous family of proteins known to serve as scaffold proteins for diverse protein complexes. Light and electron microscopic immunolocalization methods have revealed striatins in mammalian cell-cell adherens junctions (AJs). In simple epithelia, we have localized striatins as constitutive components of the plaques of the subapical zonulae adhaerentes of cells, including intestinal, glandular, ductal and urothelial cells and hepatocytes. Striatins colocalize with E-cadherin or E-N-cadherin heterodimers and with the plaque proteins α- and β-catenin, p120 and p0071. In some epithelia and carcinomas and in cultured cells derived therefrom, striatins are also seen in lateral AJs. In stratified epithelia and in corresponding squamous cell carcinomas, striatins can be found in plaques of some forms of tessellate junctions. Moreover, striatins are major plaque proteins of composite junctions (CJs; areae compositae) in the intercalated disks connecting cardiomyocytes, colocalizing with other CJ molecules, including plectin and ankyrin-G. We discuss the "multimodulator" scaffold roles of striatins in the initiation and regulation of the formation of various complex particles and structures. We propose that striatins are included in the diagnostic candidate list of proteins that, in the CJs of human hearts, can occur in mutated forms in the pathogeneses of hereditary cardiomyopathies, as seen in some types of genetically determined heart damage in boxer dogs. PMID:25501894

  5. Serial lung model for simulation and parameter estimation in body plethysmography.

    PubMed

    Verbraak, A F; Bogaard, J M; Beneken, J E; Hoorn, E; Versprille, A

    1991-05-01

    A serial lung model with a compressible segment has been implemented to simulate different types of lung and airway disorders such as asthma, emphysema, fibrosis and upper airway obstruction. The model described can be used during normal breathing, and moreover the compliant segment is structured according to more recent physiological data. A parameter estimation technique was applied and its reliability and uniqueness were tested by means of sine wave input signals. The characteristics of the alveolar pressure/flow patterns simulated with the model agree to a great extent with those found in the literature. In the case of absence of noise the parameter estimation routine produced unique solutions for different simulated pathologic classes. The sensitivity of the different parameters depended on the values belonging to each class of pathology. Some more simplified models are presented and their advantages over the complex model in special types of pathology are demonstrated. Noise added to the simulated flow appeared to have no influence on the estimated parameters, in contradiction to the effects with noise added to the pressure signal. In that case effective resistance was accurately estimated. Where parameters had no influence, as for instance upper airway resistance in emphysema or peripheral airway resistance in upper airway obstruction, the measurement accuracy was less. In all other cases, a satisfactory accuracy could be obtained. PMID:1943264

  6. The Peter Brojde Lung Cancer Centre: a model of integrative practice

    PubMed Central

    Grossman, M.; Agulnik, J.; Batist, G.

    2012-01-01

    Background The generally poor prognosis and poor quality of life for lung cancer patients have highlighted the need for a conceptual model of integrative practice. Although the philosophy of integrative oncology is well described, conceptual models that could guide the implementation and scientific evaluation of integrative practice are lacking. Purpose The present paper describes a conceptual model of integrative practice in which the philosophical underpinnings derive mainly from integrative oncology, with important contributions from Traditional Chinese Medicine (tcm) and the discipline of nursing. The conceptual model is described in terms of its purpose, values, concepts, dynamic components, scientific evidence, clinical approach, and theoretical underpinnings. The model argues that these components delineate the initial scope and orientation of integrative practice. They serve as the needed context for evaluating and interpreting the effectiveness of clinical interventions in enhancing patient outcomes in lung cancer at various phases of the illness. Furthermore, the development of relevant and effective integrative clinical interventions requires new research methods based on whole-systems research. An initial focus would be the identification of interrelationship patterns among variables that influence clinical interventions and their targeted patient outcomes. PMID:22670104

  7. Simulating solid lung nodules in MDCT images for CAD evaluation: modeling, validation, and applications

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangwei; Olcott, E.; Raffy, Philippe; Yu, Naichang; Chui, Haili

    2007-03-01

    A new lung nodule simulation model was designed to create and insert synthetic solid lung nodules, with shapes and density similar to real nodules, into normal MDCT chest exams. Nodule shapes were modeled using linearly deformed superquadrics with added randomly generated high dimensional deformations. Nodule density statistics and attenuation profiles were extracted from a group of real nodule samples, by dissecting each real nodule digitally layer by layer from the border to the core. A nodule created with modeled shape and density was inserted into real CT images by creating volume average layers using weighted averaging between nodule density and background density for each voxel. The nodule simulation model was validated both subjectively by human experts and quantitatively by comparing density attenuation profiles of simulated nodules with real nodules. These validation studies demonstrated a high level of similarity between the synthetic nodules and real nodules. This nodule simulation model was used to create objective test databases for use in evaluating a CAD system. The evaluation study showed that the CAD system was accurate in detection and volume measurement for isolated nodules, and also performed relatively well for juxta-vascular nodules. The CAD system also demonstrated stable performances for different dosages.

  8. Expansion of CTCs from early stage lung cancer patients using a microfluidic co-culture model

    PubMed Central

    Zhang, Zhuo; Shiratsuchi, Hiroe; Lin, Jules; Chen, Guoan; Reddy, Rishindra M.; Azizi, Ebrahim; Fouladdel, Shamileh; Chang, Andrew C.; Lin, Lin; Jiang, Hui; Waghray, Meghna; Luker, Gary; Simeone, Diane M.; Wicha, Max S.; Beer, David G.; Ramnath, Nithya; Nagrath, Sunitha

    2014-01-01

    The potential utility of circulating tumor cells (CTCs) to guide clinical care in oncology patients has gained momentum with emerging micro- and nanotechnologies. Establishing the role of CTCs in tumor progression and metastasis depends both on enumeration and on obtaining sufficient numbers of CTCs for downstream assays. The numbers of CTCs are few in early stages of cancer, limiting detailed molecular characterization. Recent attempts in the literature to culture CTCs isolated from metastatic patients using monoculture have had limited success rates of less than 20%. Herein, we have developed a novel in-situ capture and culture methodology for ex-vivo expansion of CTCs using a three dimensional co-culture model, simulating a tumor microenvironment to support tumor development. We have successfully expanded CTCs isolated from 14 of 19 early stage lung cancer patients. Expanded lung CTCs carried mutations of the TP53 gene identical to those observed in the matched primary tumors. Next-generation sequencing further revealed additional matched mutations between primary tumor and CTCs of cancer-related genes. This strategy sets the stage to further characterize the biology of CTCs derived from patients with early lung cancers, thereby leading to a better understanding of these putative drivers of metastasis. PMID:25474037

  9. Recruitment maneuver: RAMP versus CPAP pressure profile in a model of acute lung injury.

    PubMed

    Riva, D R; Contador, R S; Baez-Garcia, C S N; Xisto, D G; Cagido, V R; Martini, S V; Morales, M M; Rocco, P R M; Faffe, D S; Zin, W A

    2009-10-31

    We examined whether recruitment maneuvers (RMs) with gradual increase in airway pressure (RAMP) provide better outcome than continuous positive airway pressure (CPAP) in paraquat-induced acute lung injury (ALI). Wistar rats received saline intraperitoneally (0.5 mL, CTRL) or paraquat (15 mg/kg, ALI). Twenty-four hours later lung mechanics [static elastance, viscoelastic component of elastance, resistive, viscoelastic and total pressures] were determined before and after recruitment with 40cmH2O CPAP for 40s or 40-s-long slow increase in pressure up to 40cmH2O (RAMP) followed by 0 or 5 cmH2O PEEP. Fractional area of alveolar collapse and PCIII mRNA were determined. All mechanical parameters and the fraction area of alveolar collapse were higher in ALI compared to CTRL. Only RAMP-PEEP maneuver significantly improved lung mechanics and decreased PCIII mRNA expression (53%) compared with ALI, while both RMs followed by PEEP decreased alveolar collapse. In conclusion, in the present experimental ALI model, RAMP followed by 5cm H2O PEEP yields a better outcome. PMID:19712760

  10. Effect of Bile Acid on Fetal Lung in Rat Model of Intrahepatic Cholestasis of Pregnancy

    PubMed Central

    Yu, Ling; Ding, Yiling; Huang, Ting; Huang, Xiaoxia

    2014-01-01

    Objective. To determine the correlation between maternal bile acid (BA) level and fetal pulmonary surfactant in rats and study the effects of BA on fetal lung in rat model of intrahepatic cholestasis of pregnancy. Methods. Forty pregnant rats were treated with (A) 5.5 mg/kg BA, (B) 1.4 mg/kg BA, and (C) 1 ml physiological saline. Levels of total bile acid (TBA), ALT, AST, TBIL, DBIL, and SP-A were determined and the lungs of fetal rats were analyzed for pathological changes. Results. Groups A and B intervened with BA showed significant higher level of TBA in both maternal and fetal serum, more mortality rate of fetal rats, more concentration of SP-A in fetal serum, and wider alveolus mesenchyme of fetal rats than the control Group C. Higher level of BA associated with increased fetal risk and lower numerical density of mitochondria in type II alveolar epithelial cells. The levels of TBA in maternal serum were found to have significant positive correlation with those in fetal serum and SP-A level but negatively with the area of alveolus and the numerical density of lamellar body. Conclusions. The TBA level in maternal serum showed significant association with lung pathological changes in fetal rats. PMID:24778648

  11. Stable Small Animal Mechanical Ventilation for Dynamic Lung Imaging to Support Computational Fluid Dynamics Models

    SciTech Connect

    Jacob, Rick E.; Lamm, W. J.

    2011-11-08

    Pulmonary computational fluid dynamics models require 3D images to be acquired over multiple points in the dynamic breathing cycle, with no breath holds or changes in ventilatory mechanics. With small animals, these requirements result in long imaging times ({approx}90 minutes), over which lung mechanics, such as compliance, can gradually change if not carefully monitored and controlled. These changes, caused by derecruitment of parenchymal tissue, are manifested as an upward drift in peak inspiratory pressure or by changes in the pressure waveform and/or lung volume over the course of the experiment. We demonstrate highly repeatable mechanical ventilation in anesthetized rats over a long duration for pulmonary CT imaging throughout the dynamic breathing cycle. We describe significant updates to a basic commercial ventilator that was acquired for these experiments. Key to achieving consistent results was the implementation of periodic deep breaths, or sighs, of extended duration to maintain lung recruitment. In addition, continuous monitoring of breath-to-breath pressure and volume waveforms and long-term trends in peak inspiratory pressure and flow provide diagnostics of changes in breathing mechanics.

  12. Interaction of Mycoplasma pneumoniae with human lung fibroblasts: characterization of the in vitro model.

    PubMed Central

    Gabridge, M G; Taylor-Robinson, D; Davies, H A; Dourmashkin, R R

    1979-01-01

    The interaction of pathogenic Mycoplasma pneumoniae and host cells was studied in cell cultures of MRC-5 human lung fibroblasts. A comparison of results obtained with fibroblasts in a monolayer format and with hamster tracheal explant cultures indicated that the former can bind significantly larger numbers of mycoplasmas. In addition, the attachment was 96% specific, that is, mediated through a neuraminidase-sensitive receptor on the host cell. Uptake of mycoplasmas was directly related to the number of mycoplasma cells present in the inoculum, and attachment was virtually complete within a 30-min period at 37 degrees C. High doses of M. pneumoniae induced a marked cytopathic effect, whereas doses of less than or equal to 10(6) colony-forming units per ml produced grossly observable cell damage that was moderate and variable. Transmission electron microscopy studies indicated that attachment of M. pneumoniae to the surface of lung fibroblasts occurred with the specialized terminal structure or binding site oriented closest to the epithelial cell surface. The filamentous mycoplasma cells were spatially arranged in several configurations and were not limited to a vertical orientation. The advantages and disadvantages of human lung fibroblast monolayer cultures, in reference to other in vitro models are discussed. A new mycoplasma agar medium (G-200 agar) with a defined tissue culture base and 10% horse serum is also described. Images PMID:113348

  13. Lypd8 promotes the segregation of flagellated microbiota and colonic epithelia.

    PubMed

    Okumura, Ryu; Kurakawa, Takashi; Nakano, Takashi; Kayama, Hisako; Kinoshita, Makoto; Motooka, Daisuke; Gotoh, Kazuyoshi; Kimura, Taishi; Kamiyama, Naganori; Kusu, Takashi; Ueda, Yoshiyasu; Wu, Hong; Iijima, Hideki; Barman, Soumik; Osawa, Hideki; Matsuno, Hiroshi; Nishimura, Junichi; Ohba, Yusuke; Nakamura, Shota; Iida, Tetsuya; Yamamoto, Masahiro; Umemoto, Eiji; Sano, Koichi; Takeda, Kiyoshi

    2016-04-01

    Colonic epithelial cells are covered by thick inner and outer mucus layers. The inner mucus layer is free of commensal microbiota, which contributes to the maintenance of gut homeostasis. In the small intestine, molecules critical for prevention of bacterial invasion into epithelia such as Paneth-cell-derived anti-microbial peptides and regenerating islet-derived 3 (RegIII) family proteins have been identified. Although there are mucus layers providing physical barriers against the large number of microbiota present in the large intestine, the mechanisms that separate bacteria and colonic epithelia are not fully elucidated. Here we show that Ly6/PLAUR domain containing 8 (Lypd8) protein prevents flagellated microbiota invading the colonic epithelia in mice. Lypd8, selectively expressed in epithelial cells at the uppermost layer of the large intestinal gland, was secreted into the lumen and bound flagellated bacteria including Proteus mirabilis. In the absence of Lypd8, bacteria were present in the inner mucus layer and many flagellated bacteria invaded epithelia. Lypd8(-/-) mice were highly sensitive to intestinal inflammation induced by dextran sulfate sodium (DSS). Antibiotic elimination of Gram-negative flagellated bacteria restored the bacterial-free state of the inner mucus layer and ameliorated DSS-induced intestinal inflammation in Lypd8(-/-) mice. Lypd8 bound to flagella and suppressed motility of flagellated bacteria. Thus, Lypd8 mediates segregation of intestinal bacteria and epithelial cells in the colon to preserve intestinal homeostasis. PMID:27027293

  14. Acute regulation of tight junction ion selectivity in human airway epithelia

    PubMed Central

    Flynn, Andrea N.; Itani, Omar A.; Moninger, Thomas O.; Welsh, Michael J.

    2009-01-01

    Electrolyte transport through and between airway epithelial cells controls the quantity and composition of the overlying liquid. Many studies have shown acute regulation of transcellular ion transport in airway epithelia. However, whether ion transport through tight junctions can also be acutely regulated is poorly understood both in airway and other epithelia. To investigate the paracellular pathway, we used primary cultures of differentiated human airway epithelia and assessed expression of claudins, the primary determinants of paracellular permeability, and measured transepithelial electrical properties, ion fluxes, and La3+ movement. Like many other tissues, airway epithelia expressed multiple claudins. Moreover, different cell types in the epithelium expressed the same pattern of claudins. To evaluate tight junction regulation, we examined the response to histamine, an acute regulator of airway function. Histamine stimulated a rapid and transient increase in the paracellular Na+ conductance, with a smaller increase in Cl− conductance. The increase was mediated by histamine H1 receptors and depended on an increase in intracellular Ca2+ concentration. These results suggest that ion flow through the paracellular pathway can be acutely regulated. Such regulation could facilitate coupling of the passive flow of counter ions to active transcellular transport, thereby controlling net transepithelial salt and water transport. PMID:19208806

  15. cAMP stimulation of HCO3- secretion across airway epithelia.

    PubMed

    Welsh, M J; Smith, J J

    2001-07-01

    To test for the presence of HCO(3)(-) transport across airway epithelia, we measured short-circuit current in primary cultures of canine and human airway epithelia bathed in a Cl(-)-free, HCO(3)(-)/CO(2)-buffered solution. cAMP agonists stimulated a secretory current that was likely carried by HCO(3)(-) because it was absent in HCO(3)(-)-free solutions. In addition, the cAMP-stimulated current was inhibited by the carbonic anhydrase inhibitor, acetazolamide, and by the apical addition of a blocker of cystic fibrosis transmembrane conductance regulator (CFTR), diphenylamine-2-carboxylate. The current was dependent on Na(+) because it was inhibited by removing Na(+) from the submucosal solution and by inhibition of the Na(+)-K(+)-ATPase with ouabain. The cAMP-stimulated current was absent in cystic fibrosis (CF) airway epithelia. These data suggest that cAMP agonists can stimulate HCO(3)(-) secretion across airway epithelia and that CFTR may provide a conductive pathway for HCO(3)(-) movement across the apical membrane. PMID:11875274

  16. Serotonin Localization in the Turkey Vaginal but not Sperm Storage Tubule Epithelia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our knowledge regarding the mechanism of sperm selection and transport in the hen’s vagina is meager. Preliminary observations indicate the presence of non-neuron endocrine cells in the epithelia lining the lumina of the turkey hen vagina and uterovaginal junction. While no cells in the vagina or U...

  17. EFFECTS OF INGESTED ARSENIC ON DNA AND CHROMOSOME IN HUMAN EXFOLIATED EPITHELIA

    EPA Science Inventory

    Effects of Ingested Arsenic on DNA and Chromosome in Human Exfoliated Epithelia

    Judy L. Mumford, Human Studies Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

    Arsenic...

  18. Computational Modeling of Airway and Pulmonary Vascular Structure and Function: Development of a “Lung Physiome”

    PubMed Central

    Tawhai, M. H.; Clark, A. R.; Donovan, G. M.; Burrowes, K. S.

    2011-01-01

    Computational models of lung structure and function necessarily span multiple spatial and temporal scales, i.e., dynamic molecular interactions give rise to whole organ function, and the link between these scales cannot be fully understood if only molecular or organ-level function is considered. Here, we review progress in constructing multiscale finite element models of lung structure and function that are aimed at providing a computational framework for bridging the spatial scales from molecular to whole organ. These include structural models of the intact lung, embedded models of the pulmonary airways that couple to model lung tissue, and models of the pulmonary vasculature that account for distinct structural differences at the extra- and intra-acinar levels. Biophysically based functional models for tissue deformation, pulmonary blood flow, and airway bronchoconstriction are also described. The development of these advanced multiscale models has led to a better understanding of complex physiological mechanisms that govern regional lung perfusion and emergent heterogeneity during bronchoconstriction. PMID:22011236

  19. Overexpressing mouse model demonstrates the protective role of Muc5ac in the lungs.

    PubMed

    Ehre, Camille; Worthington, Erin N; Liesman, Rachael M; Grubb, Barbara R; Barbier, Diane; O'Neal, Wanda K; Sallenave, Jean-Michel; Pickles, Raymond J; Boucher, Richard C

    2012-10-01

    MUC5AC, a major gel-forming mucin expressed in the lungs, is secreted at increased rates in response to infectious agents, implying that mucins exert a protective role against inhaled pathogens. However, epidemiological and pathological studies suggest that excessive mucin secretion causes airways obstruction and inflammation. To determine whether increased MUC5AC secretion alone produces airway obstruction and/or inflammation, we generated a mouse model overexpressing Muc5ac mRNA ~20-fold in the lungs, using the rCCSP promoter. The Muc5ac cDNA was cloned from mouse lungs and tagged internally with GFP. Bronchoalveolar lavage fluid (BALF) analysis demonstrated an approximate 18-fold increase in Muc5ac protein, which formed high-molecular-weight polymers. Histopathological studies and cell counts revealed no airway mucus obstruction or inflammation in the lungs of Muc5ac-transgenic (Muc5ac-Tg) mice. Mucus clearance was preserved, implying that the excess Muc5ac secretion produced an "expanded" rather than more concentrated mucus layer, a prediction confirmed by electron microscopy. To test whether the larger mucus barrier conferred increased protection against pathogens, Muc5ac-Tg animals were challenged with PR8/H1N1 influenza viruses and showed significant decreases in infection and neutrophilic responses. Plaque assay experiments demonstrated that Muc5ac-Tg BALF and purified Muc5ac reduced infection, likely via binding to α2,3-linked sialic acids, consistent with influenza protection in vivo. In conclusion, the normal mucus transport and absence of a pulmonary phenotype in Muc5ac-Tg mice suggests that mucin hypersecretion alone is not sufficient to trigger luminal mucus plugging or airways inflammation/goblet cell hyperplasia. In contrast, increased Muc5ac secretion appears to exhibit a protective role against influenza infection. PMID:23012413

  20. Overexpressing mouse model demonstrates the protective role of Muc5ac in the lungs

    PubMed Central

    Ehre, Camille; Worthington, Erin N.; Liesman, Rachael M.; Grubb, Barbara R.; Barbier, Diane; O’Neal, Wanda K.; Sallenave, Jean-Michel; Pickles, Raymond J.; Boucher, Richard C.

    2012-01-01

    MUC5AC, a major gel-forming mucin expressed in the lungs, is secreted at increased rates in response to infectious agents, implying that mucins exert a protective role against inhaled pathogens. However, epidemiological and pathological studies suggest that excessive mucin secretion causes airways obstruction and inflammation. To determine whether increased MUC5AC secretion alone produces airway obstruction and/or inflammation, we generated a mouse model overexpressing Muc5ac mRNA ∼20-fold in the lungs, using the rCCSP promoter. The Muc5ac cDNA was cloned from mouse lungs and tagged internally with GFP. Bronchoalveolar lavage fluid (BALF) analysis demonstrated an approximate 18-fold increase in Muc5ac protein, which formed high-molecular-weight polymers. Histopathological studies and cell counts revealed no airway mucus obstruction or inflammation in the lungs of Muc5ac-transgenic (Muc5ac-Tg) mice. Mucus clearance was preserved, implying that the excess Muc5ac secretion produced an “expanded” rather than more concentrated mucus layer, a prediction confirmed by electron microscopy. To test whether the larger mucus barrier conferred increased protection against pathogens, Muc5ac-Tg animals were challenged with PR8/H1N1 influenza viruses and showed significant decreases in infection and neutrophilic responses. Plaque assay experiments demonstrated that Muc5ac-Tg BALF and purified Muc5ac reduced infection, likely via binding to α2,3-linked sialic acids, consistent with influenza protection in vivo. In conclusion, the normal mucus transport and absence of a pulmonary phenotype in Muc5ac-Tg mice suggests that mucin hypersecretion alone is not sufficient to trigger luminal mucus plugging or airways inflammation/goblet cell hyperplasia. In contrast, increased Muc5ac secretion appears to exhibit a protective role against influenza infection. PMID:23012413

  1. Activity and local delivery of azithromycin in a mouse model of Haemophilus influenzae lung infection.

    PubMed Central

    Vallée, E; Azoulay-Dupuis, E; Pocidalo, J J; Bergogne-Bérézin, E

    1992-01-01

    We compared the activities of azithromycin and erythromycin against Haemophilus influenzae in a mouse model of nonparenchymatous lower respiratory tract infection. In vitro and in vivo efficacy data for both drugs were analyzed relative to their pharmacokinetics in lungs and in vivo uptake by phagocytes. Aged C57BL/6 mice (mean age, 15.1 +/- 1.9 months) were infected intratracheally with 10(8) CFU of H. influenzae serotype b. Oral drug administration was initiated 4 h after infection by various dosage regimens. In terms of bacterial killing in the lung, azithromycin was much more active than erythromycin (P less than 0.01). Its in vivo activity was also more durable after a single administration relative to the durability of three doses of erythromycin given at 6-h intervals. The MIC of azithromycin was eightfold lower than that of erythromycin, and better penetration and a longer half-life in lung tissue were achieved after a single oral administration. Phagocytes delivered increased amounts of both drugs to the infected lungs, particularly at the site of infection (bronchoalveolar airspaces), and detectable levels of azithromycin were maintained locally for long periods. The fact that the efficacy of azithromycin coincided with the arrival of large numbers of polymorphonuclear leukocytes within the airspaces suggests that active extracellular concentrations were provided by the release of azithromycin from these cells. This further supports the potential value of once-daily azithromycin regimens for the treatment of lower respiratory tract infections in humans, provided that inhibitory concentrations against common pathogens such as H. influenzae are maintained for adequate periods of time. PMID:1324644

  2. Robust Unidirectional Airflow through Avian Lungs: New Insights from a Piecewise Linear Mathematical Model.

    PubMed

    Harvey, Emily P; Ben-Tal, Alona

    2016-02-01

    Avian lungs are remarkably different from mammalian lungs in that air flows unidirectionally through rigid tubes in which gas exchange occurs. Experimental observations have been able to determine the pattern of gas flow in the respiratory system, but understanding how the flow pattern is generated and determining the factors contributing to the observed dynamics remains elusive. It has been hypothesized that the unidirectional flow is due to aerodynamic valving during inspiration and expiration, resulting from the anatomical structure and the fluid dynamics involved, however, theoretical studies to back up this hypothesis are lacking. We have constructed a novel mathematical model of the airflow in the avian respiratory system that can produce unidirectional flow which is robust to changes in model parameters, breathing frequency and breathing amplitude. The model consists of two piecewise linear ordinary differential equations with lumped parameters and discontinuous, flow-dependent resistances that mimic the experimental observations. Using dynamical systems techniques and numerical analysis, we show that unidirectional flow can be produced by either effective inspiratory or effective expiratory valving, but that both inspiratory and expiratory valving are required to produce the high efficiencies of flows observed in avian lungs. We further show that the efficacy of the inspiratory and expiratory valving depends on airsac compliances and airflow resistances that may not be located in the immediate area of the valving. Our model provides additional novel insights; for example, we show that physiologically realistic resistance values lead to efficiencies that are close to maximum, and that when the relative lumped compliances of the caudal and cranial airsacs vary, it affects the timing of the airflow across the gas exchange area. These and other insights obtained by our study significantly enhance our understanding of the operation of the avian respiratory

  3. Modeling the competition between lung metastases and the immune system using agents

    PubMed Central

    2010-01-01

    Background The Triplex cell vaccine is a cancer cellular vaccine that can prevent almost completely the mammary tumor onset in HER-2/neu transgenic mice. In a translational perspective, the activity of the Triplex vaccine was also investigated against lung metastases showing that the vaccine is an effective treatment also for the cure of metastases. A future human application of the Triplex vaccine should take into account several aspects of biological behavior of the involved entities to improve the efficacy of therapeutic treatment and to try to predict, for example, the outcomes of longer experiments in order to move faster towards clinical phase I trials. To help to address this problem, MetastaSim, a hybrid Agent Based - ODE model for the simulation of the vaccine-elicited immune system response against lung metastases in mice is presented. The model is used as in silico wet-lab. As a first application MetastaSim is used to find protocols capable of maximizing the total number of prevented metastases, minimizing the number of vaccine administrations. Results The model shows that it is possible to obtain "in silico" a 45% reduction in the number of vaccinations. The analysis of the results further suggests that any optimal protocol for preventing lung metastases formation should be composed by an initial massive vaccine dosage followed by few vaccine recalls. Conclusions Such a reduction may represent an important result from the point of view of translational medicine to humans, since a downsizing of the number of vaccinations is usually advisable in order to minimize undesirable effects. The suggested vaccination strategy also represents a notable outcome. Even if this strategy is commonly used for many infectious diseases such as tetanus and hepatitis-B, it can be in fact considered as a relevant result in the field of cancer-vaccines immunotherapy. These results can be then used and verified in future "in vivo" experiments, and their outcome can be used to

  4. Robust Unidirectional Airflow through Avian Lungs: New Insights from a Piecewise Linear Mathematical Model

    PubMed Central

    Harvey, Emily P.; Ben-Tal, Alona

    2016-01-01

    Avian lungs are remarkably different from mammalian lungs in that air flows unidirectionally through rigid tubes in which gas exchange occurs. Experimental observations have been able to determine the pattern of gas flow in the respiratory system, but understanding how the flow pattern is generated and determining the factors contributing to the observed dynamics remains elusive. It has been hypothesized that the unidirectional flow is due to aerodynamic valving during inspiration and expiration, resulting from the anatomical structure and the fluid dynamics involved, however, theoretical studies to back up this hypothesis are lacking. We have constructed a novel mathematical model of the airflow in the avian respiratory system that can produce unidirectional flow which is robust to changes in model parameters, breathing frequency and breathing amplitude. The model consists of two piecewise linear ordinary differential equations with lumped parameters and discontinuous, flow-dependent resistances that mimic the experimental observations. Using dynamical systems techniques and numerical analysis, we show that unidirectional flow can be produced by either effective inspiratory or effective expiratory valving, but that both inspiratory and expiratory valving are required to produce the high efficiencies of flows observed in avian lungs. We further show that the efficacy of the inspiratory and expiratory valving depends on airsac compliances and airflow resistances that may not be located in the immediate area of the valving. Our model provides additional novel insights; for example, we show that physiologically realistic resistance values lead to efficiencies that are close to maximum, and that when the relative lumped compliances of the caudal and cranial airsacs vary, it affects the timing of the airflow across the gas exchange area. These and other insights obtained by our study significantly enhance our understanding of the operation of the avian respiratory

  5. SU-E-J-163: A Biomechanical Lung Model for Respiratory Motion Study

    SciTech Connect

    Liu, X; Belcher, AH; Grelewicz, Z; Wiersma, RD

    2015-06-15

    Purpose: This work presents a biomechanical model to investigate the complex respiratory motion for the lung tumor tracking in radiosurgery by computer simulation. Methods: The models include networked massspring-dampers to describe the tumor motion, different types of surrogate signals, and the force generated by the diaphragm. Each mass-springdamper has the same mechanical structure and each model can have different numbers of mass-spring-dampers. Both linear and nonlinear stiffness parameters were considered, and the damping ratio was tuned in a range so that the tumor motion was over-damped (no natural tumor oscillation occurs without force from the diaphragm). The simulation was run by using ODE45 (ordinary differential equations by Runge-Kutta method) in MATLAB, and all time courses of motions and inputs (force) were generated and compared. Results: The curvature of the motion time courses around their peaks was sensitive to the damping ratio. Therefore, the damping ratio can be determined based on the clinical data of a high sampling rate. The peak values of different signals and the time the peaks occurred were compared, and it was found that the diaphragm force had a time lead over the tumor motion, and the lead time (0.1–0.4 seconds) depended on the distance between the tumor and the diaphragm. Conclusion: We reported a model based analysis approach for the spatial and temporal relation between the motion of the lung tumor and the surrogate signals. Due to the phase lead of the diaphragm in comparing with the lung tumor motion, the measurement of diaphragm motion (or its electromyography signal) can be used as a beam gating signal in radiosurgery, and it can also be an additional surrogate signal for better tumor motion tracking. The research is funded by the American Cancer Society (ACS) grant. The grant name is: Frameless SRS Based on Robotic Head Motion Cancellation. The grant number is: RSG-13-313-01-CCE.

  6. Renal epithelia in long term gradient culture for biomaterial testing and tissue engineering.

    PubMed

    Minuth, Will W; Schumacher, Karl; Strehl, Raimund

    2005-01-01

    In the organism epithelia perform perfect barrier functions. Strong rheological and mechanical influences constitute the normal environment of this tissue throughout life. Most epithelia are exposed to different fluids at the luminal and basal sides. To obtain realistic information about tissue development in modern biomaterial testing and tissue engineering it is necessary to mimick the natural environment of epithelia. Cultured cells are brought in contact with an artificial extracellular matrix to determine whether proper development into a functional epithelium occurs. As under natural conditions the cultures have to withstand mechanical and fluid stress over a prolonged period of time in close contact to a selected biomaterial. However, development of tissue-specific features such as polarization, tightness and transport under in vitro conditions will only occur, if the biomaterial and the culture conditions support tissue development. Leakage, edge damage and pressure differences during culture have to be avoided so that the natural functions of the growing epithelium can develop. Our aim is to generate functional epithelia derived from renal explants containing stem cells, which are microsurgically isolated and placed into specific O-ring carriers for optimal handling. The cells develop in combination with a collagenous matrix from an embryonic into a functional collecting duct (rCD) epithelium. To achieve optimal culture conditions the tissue is placed in a gradient culture container. A typical environment can be simulated by superfusing different culture media at the luminal and basal sides. Within days epithelia growing inside the gradient container build up a physiological barrier, which is maintained during the whole culture period. The described method allows to investigate the influence of new biomaterials over prolonged periods of time. PMID:15623930

  7. Activation of an apical Cl- conductance by Ca2+ ionophores in cystic fibrosis airway epithelia.

    PubMed

    Willumsen, N J; Boucher, R C

    1989-02-01

    Cystic fibrosis (CF) airway epithelia express a defect in adenosine 3',5'-cyclic monophosphate (cAMP)-dependent regulation of apical membrane Cl- channels. Recent patch-clamp studies have raised the possibility that Ca2+ -dependent mechanisms for the activation of Cl- secretion may be preserved in CF airway epithelia. To determine 1) whether intact normal (N1) and CF airway epithelia exhibit a Ca2+ -dependent mechanism for activation of Cl- secretion and 2) whether Ca2+ -dependent mechanism for activation of Cl- secretion and 2) whether Ca2+ -dependent mechanisms initiate Cl- secretion via activation of an apical membrane Cl- conductance (GCl-), nasal epithelia from N1 and CF subjects were cultured on collagen membranes, and responses to isoproterenol or Ca2- ionophores [A23187 10(-6) M; ionomycin (10(-5)M)] were measured with transepithelial and intracellular techniques. Isoproterenol induced activation of an apical membrane GCl- in N1 cultures but was ineffective in CF. In contrast, in both N1 and CF amiloride-pretreated cultures, A23187 induced an increase in the equivalent short-circuit current that was associated with an activation of an apical membrane Gc1- and was bumetanide inhibitable. A23187 addition during superfusion of the lumen with a low Cl- (3 mM) solution reduced intracellular Cl- activity of CF cells. A Ca2+ ionophore of different selectivity properties, ionomycin, was also an effective Cl- secretagogue in both N1 and CF cultures. We conclude that 1) the A23187 induced Cl- secretion via activation of an apical GCl- in N1 human nasal epithelium, and 2) in contrast to an isoproterenol-dependent path, a Ca2+ -dependent path for GCl- activation is preserved in CF epithelia. PMID:2465689

  8. A novel method for right one-lung ventilation modeling in rabbits

    PubMed Central

    Xu, Ze-Ping; Gu, Lian-Bing; Bian, Qing-Ming; Li, Peng-Yi; Wang, Li-Jun; Chen, Xiao-Xiang; Zhang, Jing-Yuan

    2016-01-01

    There is no standard method by which to establish a right one-lung ventilation (OLV) model in rabbits. In the present study, a novel method is proposed to compare with two other methods. After 0.5 h of baseline two-lung ventilation (TLV), 40 rabbits were randomly divided into sham group (TLV for 3 h as a contrast) and three right-OLV groups (right OLV for 3 h with different methods): Deep intubation group, clamp group and blocker group (deeply intubate the self-made bronchial blocker into the left main bronchus, the novel method). These three methods were compared using a number of variables: Circulation by heart rate (HR), mean arterial pressure (MAP); oxygenation by arterial blood gas analysis; airway pressure; lung injury by histopathology; and time, blood loss, success rate of modeling. Following OLV, compared with the sham group, arterial partial pressure of oxygen and arterial hemoglobin oxygen saturation decreased, peak pressure increased and lung injury scores were higher in three OLV groups at 3 h of OLV. All these indexes showed no differences between the three OLV groups. During right-OLV modeling, less time was spent in the blocker group (6±2 min), compared with the other two OLV groups (13±4 min in deep intubation group, P<0.05; 33±9 min in clamp group, P<0.001); more blood loss was observed in clamp group (11.7±2.8 ml), compared with the other two OLV groups (2.3±0.5 ml in deep intubation group, P<0.001; 2.1±0.6 ml in blocker group, P<0.001). The first-time and final success rate of modeling showed no differences among the three OLV groups. Deep intubation of the self-made bronchial blocker into the left main bronchus is an easy, effective and reliable method to establish a right-OLV model in rabbits. PMID:27446346

  9. Image-guided radiotherapy platform using single nodule conditional lung cancer mouse models

    PubMed Central

    Herter-Sprie, Grit S.; Korideck, Houari; Christensen, Camilla L.; Herter, Jan M.; Rhee, Kevin; Berbeco, Ross I.; Bennett, David G.; Akbay, Esra A.; Kozono, David; Mak, Raymond H.; Makrigiorgos, G. Mike; Kimmelman, Alec C.; Wong, Kwok-Kin

    2014-01-01

    Close resemblance of murine and human trials is essential to achieve the best predictive value of animal-based translational cancer research. Kras-driven genetically engineered mouse models of non-small cell lung cancer faithfully predict the response of human lung cancers to systemic chemotherapy. Due to development of multifocal disease, however, these models have not been usable in studies of outcomes following focal radiotherapy (RT). We report the development of a preclinical platform to deliver state-of-the-art image-guided RT in these models. Presence of a single tumour as usually diagnosed in patients is modelled by confined injection of adenoviral Cre recombinase. Furthermore, three-dimensional conformal planning and state-of-the-art image-guided dose delivery are performed as in humans. We evaluate treatment efficacies of two different radiation regimens and find that Kras-driven tumours can temporarily be stabilized upon RT, whereas additional loss of either Lkb1 or p53 renders these lesions less responsive to RT. PMID:25519892

  10. Dynamic tracheal occlusion improves lung morphometrics and function in the fetal lamb model of congenital diaphragmatic hernia

    PubMed Central

    Jelin, Eric B.; Etemadi, Mozziyar; Encinas, Jose; Schecter, Samuel C.; Chapin, Cheryl; Wu, Jianfeng; Guevara-Gallardo, Salvador; Nijagal, Amar; Gonzales, Kelly D.; Ferrier, William T.; Roy, Shuvo; Miniati, Doug

    2011-01-01

    Background Congenital diaphragmatic hernia (CDH) is associated with significant neonatal morbidity and mortality. Although prenatal complete tracheal occlusion (cTO) causes hypoplastic CDH lungs to enlarge, improved lung function has not been demonstrated. Furthermore, cTO interferes with the dynamic pressure change and fluid flow associated with fetal breathing. Purpose To assess a novel dynamic tracheal occlusion (dTO) device that preserves pressure changes and fluid flow. Methods In this pilot study, CDH was created in fetal lambs at 65 days gestational age (GA). At 110 days GA, a cTO device (n=3) or a dTO device (n=4) was placed in the fetal trachea. At 135 days GA, lambs were delivered and resuscitated. Unoperated lamb co-twins (n=5), sham thoracotomy lambs (n=2), and untreated CDH lambs (n=3) served as controls. Results Tracheal opening pressure, lung volume, lung fluid total protein, and phospholipid were significantly higher in the cTO group than in the dTO and unoperated control groups. Maximal oxygenation and lung compliance were significantly lower in the cTO group when compared to the unoperated control and dTO groups. Conclusion Preliminary results suggest that in the fetal lamb CDH model, dTO restores normal lung morphometrics and function, whereas cTO leads to enlarged but less functional lungs. PMID:21683214

  11. Lung Transplant

    MedlinePlus

    ... the NHLBI on Twitter. What Is a Lung Transplant? A lung transplant is surgery to remove a person's diseased lung ... a healthy lung from a deceased donor. Lung transplants are used for people who are likely to ...

  12. Imatinib attenuates inflammation and vascular leak in a clinically relevant two-hit model of acute lung injury.

    PubMed

    Rizzo, Alicia N; Sammani, Saad; Esquinca, Adilene E; Jacobson, Jeffrey R; Garcia, Joe G N; Letsiou, Eleftheria; Dudek, Steven M

    2015-12-01

    Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), an illness characterized by life-threatening vascular leak, is a significant cause of morbidity and mortality in critically ill patients. Recent preclinical studies and clinical observations have suggested a potential role for the chemotherapeutic agent imatinib in restoring vascular integrity. Our prior work demonstrates differential effects of imatinib in mouse models of ALI, namely attenuation of LPS-induced lung injury but exacerbation of ventilator-induced lung injury (VILI). Because of the critical role of mechanical ventilation in the care of patients with ARDS, in the present study we pursued an assessment of the effectiveness of imatinib in a "two-hit" model of ALI caused by combined LPS and VILI. Imatinib significantly decreased bronchoalveolar lavage protein, total cells, neutrophils, and TNF-α levels in mice exposed to LPS plus VILI, indicating that it attenuates ALI in this clinically relevant model. In subsequent experiments focusing on its protective role in LPS-induced lung injury, imatinib attenuated ALI when given 4 h after LPS, suggesting potential therapeutic effectiveness when given after the onset of injury. Mechanistic studies in mouse lung tissue and human lung endothelial cells revealed that imatinib inhibits LPS-induced NF-κB expression and activation. Overall, these results further characterize the therapeutic potential of imatinib against inflammatory vascular leak. PMID:26432864

  13. A Biomathematical Model of Pneumococcal Lung Infection and Antibiotic Treatment in Mice

    PubMed Central

    Schirm, Sibylle; Ahnert, Peter; Wienhold, Sandra; Mueller-Redetzky, Holger; Nouailles-Kursar, Geraldine; Loeffler, Markus; Witzenrath, Martin; Scholz, Markus

    2016-01-01

    Pneumonia is considered to be one of the leading causes of death worldwide. The outcome depends on both, proper antibiotic treatment and the effectivity of the immune response of the host. However, due to the complexity of the immunologic cascade initiated during infection, the latter cannot be predicted easily. We construct a biomathematical model of the murine immune response during infection with pneumococcus aiming at predicting the outcome of antibiotic treatment. The model consists of a number of non-linear ordinary differential equations describing dynamics of pneumococcal population, the inflammatory cytokine IL-6, neutrophils and macrophages fighting the infection and destruction of alveolar tissue due to pneumococcus. Equations were derived by translating known biological mechanisms and assuming certain response kinetics. Antibiotic therapy is modelled by a transient depletion of bacteria. Unknown model parameters were determined by fitting the predictions of the model to data sets derived from mice experiments of pneumococcal lung infection with and without antibiotic treatment. Time series of pneumococcal population, debris, neutrophils, activated epithelial cells, macrophages, monocytes and IL-6 serum concentrations were available for this purpose. The antibiotics Ampicillin and Moxifloxacin were considered. Parameter fittings resulted in a good agreement of model and data for all experimental scenarios. Identifiability of parameters is also estimated. The model can be used to predict the performance of alternative schedules of antibiotic treatment. We conclude that we established a biomathematical model of pneumococcal lung infection in mice allowing predictions regarding the outcome of different schedules of antibiotic treatment. We aim at translating the model to the human situation in the near future. PMID:27196107

  14. Acute Lung Injury and Fibrosis in a Baboon Model of Escherichia coli Sepsis

    PubMed Central

    Keshari, Ravi S.; Silasi-Mansat, Robert; Zhu, Hua; Popescu, Narcis I.; Peer, Glenn; Chaaban, Hala; Lambris, John D.; Polf, Holly; Lupu, Cristina; Kinasewitz, Gary

    2014-01-01

    Sepsis-induced inflammation of the lung leads to acute respiratory distress syndrome (ARDS), which may trigger persistent fibrosis. The pathology of ARDS is complex and poorly understood, and the therapeutic approaches are limited. We used a baboon model of Escherichia coli sepsis that mimics the complexity of human disease to study the pathophysiology of ARDS. We performed extensive biochemical, histological, and functional analyses to characterize the disease progression and the long-term effects of sepsis on the lung structure and function. Similar to humans, sepsis-induced ARDS in baboons displays an early inflammatory exudative phase, with extensive necrosis. This is followed by a regenerative phase dominated by proliferation of type 2 epithelial cells, expression of epithelial-to-mesenchymal transition markers, myofibroblast migration and proliferation, and collagen synthesis. Baboons that survived sepsis showed persistent inflammation and collagen deposition 6–27 months after the acute episodes. Long-term survivors had almost double the amount of collagen in the lung as compared with age-matched control animals. Immunostaining for procollagens showed persistent active collagen synthesis within the fibroblastic foci and interalveolar septa. Fibroblasts expressed markers of transforming growth factor-β and platelet-derived growth factor signaling, suggesting their potential role as mediators of myofibroblast migration and proliferation, and collagen deposition. In parallel, up-regulation of the inhibitors of extracellular proteases supports a deregulated matrix remodeling that may contribute to fibrosis. The primate model of sepsis-induced ARDS mimics the disease progression in humans, including chronic inflammation and long-lasting fibrosis. This model helps our understanding of the pathophysiology of fibrosis and the testing of new therapies. PMID:24066737

  15. The composition of cigarette smoke determines inflammatory cell recruitment to the lung in COPD mouse models

    PubMed Central

    John, Gerrit; Kohse, Katrin; Orasche, Jürgen; Reda, Ahmed; Schnelle-Kreis, Jürgen; Zimmermann, Ralf; Schmid, Otmar; Eickelberg, Oliver; Yildirim, Ali Önder

    2013-01-01

    COPD (chronic obstructive pulmonary disease) is caused by exposure to toxic gases and particles, most often CS (cigarette smoke), leading to emphysema, chronic bronchitis, mucus production and a subsequent decline in lung function. The disease pathogenesis is related to an abnormal CS-induced inflammatory response of the lungs. Similar to active (mainstream) smoking, second hand (sidestream) smoke exposure severely affects respiratory health. These processes can be studied in vivo in models of CS exposure of mice. We compared the acute inflammatory response of female C57BL/6 mice exposed to two concentrations [250 and 500 mg/m3 TPM (total particulate matter)] of sidestream and mainstream CS for 3 days and interpreted the biological effects based on physico-chemical differences in the gas and particulate phase composition of CS. BAL (bronchoalveolar lavage fluid) was obtained to perform differential cell counts and to measure cytokine release. Lung tissue was used to determine mRNA and protein expression of proinflammatory genes and to assess tissue inflammation. A strong acute inflammatory response characterized by neutrophilic influx, increased cytokine secretion [KC (keratinocyte chemoattractant), TNF-α (tumour necrosis factor α), MIP-2 (macrophage inflammatory protein 2), MIP-1α and MCP-1 (monocyte chemoattractant protein-1)], pro-inflammatory gene expression [KC, MIP-2 and MMP12 (matrix metalloproteinase 12)] and up-regulated GM-CSF (granulocyte macrophage colony-stimulating factor) production was observed in the mainstream model. After sidestream exposure there was a dampened inflammatory reaction consisting only of macrophages and diminished GM-CSF levels, most likely caused by elevated CO concentrations. These results demonstrate that the composition of CS determines the dynamics of inflammatory cell recruitment in COPD mouse models. Different initial inflammatory processes might contribute to COPD pathogenesis in significantly varying ways, thereby

  16. Translocation of botulinum neurotoxin serotype A and associated proteins across the intestinal epithelia

    PubMed Central

    Lam, Tina I; Stanker, Larry H; Lee, Kwangkook; Jin, Rongsheng; Cheng, Luisa W

    2015-01-01

    Botulinum neurotoxins (BoNTs) are some of the most poisonous natural toxins. Botulinum neurotoxins associate with neurotoxin-associated proteins (NAPs) forming large complexes that are protected from the harsh environment of the gastrointestinal tract. However, it is still unclear how BoNT complexes as large as 900 kDa traverse the epithelial barrier and what role NAPs play in toxin translocation. In this study, we examined the transit of BoNT serotype A (BoNT/A) holotoxin, complex and recombinantly purified NAP complex through cultured and polarized Caco-2 cells and, for the first time, in the small mouse intestine. Botulinum neurotoxin serotype A and NAPs in the toxin complex were detectable inside intestinal cells beginning at 2 h post intoxication. Appearance of the BoNT/A holotoxin signal was slower, with detection starting at 4–6 h. This indicated that the holotoxin alone was sufficient for entry but the presence of NAPs enhanced the rate of entry. Botulinum neurotoxin serotype A detection peaked at approximately 6 and 8 h for complex and holotoxin, respectively, and thereafter began to disperse with some toxin remaining in the epithelia after 24 h. Purified HA complexes alone were also internalized and followed a similar time course to that of BoNT/A complex internalization. However, recombinant HA complexes did not enhance BoNT/A holotoxin entry in the absence of a physical link with BoNT/A. We propose a model for BoNT/A toxin complex translocation whereby toxin complex entry is facilitated by NAPs in a receptor-mediated mechanism. Understanding the intestinal uptake of BoNT complexes will aid the development of new measures to prevent or treat oral intoxications. PMID:25640773

  17. Fluid transport across leaky epithelia: central role of the tight junction and supporting role of aquaporins.

    PubMed

    Fischbarg, Jorge

    2010-10-01

    The mechanism of epithelial fluid transport remains unsolved, which is partly due to inherent experimental difficulties. However, a preparation with which our laboratory works, the corneal endothelium, is a simple leaky secretory epithelium in which we have made some experimental and theoretical headway. As we have reported, transendothelial fluid movements can be generated by electrical currents as long as there is tight junction integrity. The direction of the fluid movement can be reversed by current reversal or by changing junctional electrical charges by polylysine. Residual endothelial fluid transport persists even when no anions (hence no salt) are being transported by the tissue and is only eliminated when all local recirculating electrical currents are. Aquaporin (AQP) 1 is the only AQP present in these cells, and its deletion in AQP1 null mice significantly affects cell osmotic permeability (by ∼40%) but fluid transport much less (∼20%), which militates against the presence of sizable water movements across the cell. In contrast, AQP1 null mice cells have reduced regulatory volume decrease (only 60% of control), which suggests a possible involvement of AQP1 in either the function or the expression of volume-sensitive membrane channels/transporters. A mathematical model of corneal endothelium we have developed correctly predicts experimental results only when paracellular electro-osmosis is assumed rather than transcellular local osmosis. Our evidence therefore suggests that the fluid is transported across this layer via the paracellular route by a mechanism that we attribute to electro-osmotic coupling at the junctions. From our findings we have developed a novel paradigm for this preparation that includes 1) paracellular fluid flow; 2) a crucial role for the junctions; 3) hypotonicity of the primary secretion; and 4) an AQP role in regulation rather than as a significant water pathway. These elements are remarkably similar to those proposed by the

  18. Translocation of botulinum neurotoxin serotype A and associated proteins across the intestinal epithelia.

    PubMed

    Lam, Tina I; Stanker, Larry H; Lee, Kwangkook; Jin, Rongsheng; Cheng, Luisa W

    2015-08-01

    Botulinum neurotoxins (BoNTs) are some of the most poisonous natural toxins. Botulinum neurotoxins associate with neurotoxin-associated proteins (NAPs) forming large complexes that are protected from the harsh environment of the gastrointestinal tract. However, it is still unclear how BoNT complexes as large as 900 kDa traverse the epithelial barrier and what role NAPs play in toxin translocation. In this study, we examined the transit of BoNT serotype A (BoNT/A) holotoxin, complex and recombinantly purified NAP complex through cultured and polarized Caco-2 cells and, for the first time, in the small mouse intestine. Botulinum neurotoxin serotype A and NAPs in the toxin complex were detectable inside intestinal cells beginning at 2 h post intoxication. Appearance of the BoNT/A holotoxin signal was slower, with detection starting at 4-6 h. This indicated that the holotoxin alone was sufficient for entry but the presence of NAPs enhanced the rate of entry. Botulinum neurotoxin serotype A detection peaked at approximately 6 and 8 h for complex and holotoxin, respectively, and thereafter began to disperse with some toxin remaining in the epithelia after 24 h. Purified HA complexes alone were also internalized and followed a similar time course to that of BoNT/A complex internalization. However, recombinant HA complexes did not enhance BoNT/A holotoxin entry in the absence of a physical link with BoNT/A. We propose a model for BoNT/A toxin complex translocation whereby toxin complex entry is facilitated by NAPs in a receptor-mediated mechanism. Understanding the intestinal uptake of BoNT complexes will aid the development of new measures to prevent or treat oral intoxications. PMID:25640773

  19. KL4 Peptide Induces Reversible Collapse Structures on Multiple Length Scales in Model Lung Surfactant

    PubMed Central

    Holten-Andersen, Niels; Michael Henderson, J.; Walther, Frans J.; Waring, Alan J.; Ruchala, Piotr; Notter, Robert H.; Lee, Ka Yee C.

    2011-01-01

    We investigated the effects of KL4, a 21-residue amphipathic peptide approximating the overall ratio of positively charged to hydrophobic amino acids in surfactant protein B (SP-B), on the structure and collapse of dipalmitoylphosphatidylcholine and palmitoyl-oleoyl-phosphatidylglycerol monolayers. As reported in prior work on model lung surfactant phospholipid films containing SP-B and SP-B peptides, our experiments show that KL4 improves surfactant film reversibility during repetitive interfacial cycling in association with the formation of reversible collapse structures on multiple length scales. Emphasis is on exploring a general mechanistic connection between peptide-induced nano- and microscale reversible collapse structures (silos and folds). PMID:22208194

  20. Model-based dose calculations for {sup 125}I lung brachytherapy

    SciTech Connect

    Sutherland, J. G. H.; Furutani, K. M.; Garces, Y. I.; Thomson, R. M.

    2012-07-15

    Purpose: Model-baseddose calculations (MBDCs) are performed using patient computed tomography (CT) data for patients treated with intraoperative {sup 125}I lung brachytherapy at the Mayo Clinic Rochester. Various metallic artifact correction and tissue assignment schemes are considered and their effects on dose distributions are studied. Dose distributions are compared to those calculated under TG-43 assumptions. Methods: Dose distributions for six patients are calculated using phantoms derived from patient CT data and the EGSnrc user-code BrachyDose. {sup 125}I (GE Healthcare/Oncura model 6711) seeds are fully modeled. Four metallic artifact correction schemes are applied to the CT data phantoms: (1) no correction, (2) a filtered back-projection on a modified virtual sinogram, (3) the reassignment of CT numbers above a threshold in the vicinity of the seeds, and (4) a combination of (2) and (3). Tissue assignment is based on voxel CT number and mass density is assigned using a CT number to mass density calibration. Three tissue assignment schemes with varying levels of detail (20, 11, and 5 tissues) are applied to metallic artifact corrected phantoms. Simulations are also performed under TG-43 assumptions, i.e., seeds in homogeneous water with no interseed attenuation. Results: Significant dose differences (up to 40% for D{sub 90}) are observed between uncorrected and metallic artifact corrected phantoms. For phantoms created with metallic artifact correction schemes (3) and (4), dose volume metrics are generally in good agreement (less than 2% differences for all patients) although there are significant local dose differences. The application of the three tissue assignment schemes results in differences of up to 8% for D{sub 90}; these differences vary between patients. Significant dose differences are seen between fully modeled and TG-43 calculations with TG-43 underestimating the dose (up to 36% in D{sub 90}) for larger volumes containing higher proportions of

  1. Effect of geometric variations on pressure loss for a model bifurcation of the human lung airway.

    PubMed

    Kang, Min-Yeong; Hwang, Jeongeun; Lee, Jin-Won

    2011-04-01

    Characteristics of pressure loss (ΔP) in human lung airways were numerically investigated using a realistic model bifurcation. Flow equations were numerically solved for the steady inspiratory condition with the tube length, the branching angle and flow velocity being varied over a wide range. In general, the ΔP coefficient K showed a power-law dependence on Reynolds number (Re) and length-to-diameter ratio with a different exponent for Re≥100 than for Re<100. The effect of different branching angles on pressure loss was very weak in the smooth-branching airways. PMID:21354574

  2. Branching patterns emerge in a mathematical model of the dynamics of lung development

    PubMed Central

    Guo, Yina; Chen, Ting-Hsuan; Zeng, Xingjuan; Warburton, David; Boström, Kristina I; Ho, Chih-Ming; Zhao, Xin; Garfinkel, Alan

    2014-01-01

    Recent experimental work has described an elegant pattern of branching in the development of the lung. Multiple forms of branching have been identified, including side branching and tip bifurcation. A particularly interesting feature is the phenomenon of ‘orthogonal rotation of the branching plane’. The lung must fill 3D space with the essentially 2D phenomenon of branching. It accomplishes this by rotating the branching plane by 90° with each generation. The mechanisms underlying this rotation are not understood. In general, the programmes that underlie branching have been hypothetically attributed to genetic ‘subroutines’ under the control of a ‘global master routine’ to invoke particular subroutines at the proper time and location, but the mechanisms of these routines are not known. Here, we demonstrate that fundamental mechanisms, the reaction and diffusion of biochemical morphogens, can create these patterns. We used a partial differential equation model that postulates three morphogens, which we identify with specific molecules in lung development. We found that cascades of branching events, including side branching, tip splitting and orthogonal rotation of the branching plane, all emerge immediately from the model, without further assumptions. In addition, we found that one branching mode can be easily switched to another, by increasing or decreasing the values of key parameters. This shows how a ‘global master routine’ could work by the alteration of a single parameter. Being able to simulate cascades of branching events is necessary to understand the critical features of branching, such as orthogonal rotation of the branching plane between successive generations, and branching mode switch during lung development. Thus, our model provides a paradigm for how genes could possibly act to produce these spatial structures. Our low-dimensional model gives a qualitative understanding of how generic physiological mechanisms can produce branching

  3. Maternal Interferon Regulatory Factor 6 is required for the differentiation of primary superficial epithelia in Danio and Xenopus embryos

    PubMed Central

    Sabel, Jaime L.; d’Alençon, Claudia; O’Brien, Erin K.; Van Otterloo, Eric; Lutz, Katie; Cuykendall, Tawny N.; Schutte, Brian C.; Houston, Douglas W.; Cornell