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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. 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.

  13. 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

  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. 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.

  13. 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

  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. 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

  9. 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

  10. 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

  11. 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

  12. 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

  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. 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

  15. 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

  16. 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

  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. 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

  9. 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

  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. 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

  18. 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

  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. 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)

  4. 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.

  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 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

  17. 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

  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

    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

  9. 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

  10. 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

  11. 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

  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. 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

  18. 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

  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. 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

  1. 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

  2. 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

  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. 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.

  1. 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.

  2. 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

  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.

    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

  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

    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.

  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. 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...

  18. 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

  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. 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

  5. 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

  6. 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

  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. 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.

  18. 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.

  19. 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

  20. 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

  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

    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.

  2. 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

  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. 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

  13. 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

  14. 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

  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. 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

  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. 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

  20. 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

  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. 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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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