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Perlman CE, Knudsen L, Smith BJ. The fix is not yet in: recommendation for fixation of lungs within physiological/pathophysiological volume range in preclinical pulmonary structure-function studies. Am J Physiol Lung Cell Mol Physiol 2024; 327:L218-L231. [PMID: 38712433 PMCID: PMC11444500 DOI: 10.1152/ajplung.00341.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 02/14/2024] [Accepted: 04/22/2024] [Indexed: 05/08/2024] Open
Abstract
Quantitative characterization of lung structures by morphometrical or stereological analysis of histological sections is a powerful means of elucidating pulmonary structure-function relations. The overwhelming majority of studies, however, fix lungs for histology at pressures outside the physiological/pathophysiological respiratory volume range. Thus, valuable information is being lost. In this perspective article, we argue that investigators performing pulmonary histological studies should consider whether the aims of their studies would benefit from fixation at functional transpulmonary pressures, particularly those of end-inspiration and end-expiration. We survey the pressures at which lungs are typically fixed in preclinical structure-function studies, provide examples of conditions that would benefit from histological evaluation at functional lung volumes, summarize available fixation methods, discuss alternative imaging modalities, and discuss challenges to implementing the suggested approach and means of addressing those challenges. We aim to persuade investigators that modifying or complementing the traditional histological approach by fixing lungs at minimal and maximal functional volumes could enable new understanding of pulmonary structure-function relations.
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Affiliation(s)
- Carrie E Perlman
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey, United States
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Bradford J Smith
- Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado, United States
- Section of Pulmonary and Sleep Medicine, Department of Pediatrics, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, United States
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2
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Tsikis ST, Klouda T, Hirsch TI, Fligor SC, Liu T, Kim Y, Pan A, Quigley M, Mitchell PD, Puder M, Yuan K. A pneumonectomy model to study flow-induced pulmonary hypertension and compensatory lung growth. CELL REPORTS METHODS 2023; 3:100613. [PMID: 37827157 PMCID: PMC10626210 DOI: 10.1016/j.crmeth.2023.100613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 08/01/2023] [Accepted: 09/20/2023] [Indexed: 10/14/2023]
Abstract
In newborns, developmental disorders such as congenital diaphragmatic hernia (CDH) and specific types of congenital heart disease (CHD) can lead to defective alveolarization, pulmonary hypoplasia, and pulmonary arterial hypertension (PAH). Therapeutic options for these patients are limited, emphasizing the need for new animal models representative of disease conditions. In most adult mammals, compensatory lung growth (CLG) occurs after pneumonectomy; however, the underlying relationship between CLG and flow-induced pulmonary hypertension (PH) is not fully understood. We propose a murine model that involves the simultaneous removal of the left lung and right caval lobe (extended pneumonectomy), which results in reduced CLG and exacerbated reproducible PH. Extended pneumonectomy in mice is a promising animal model to study the cellular response and molecular mechanisms contributing to flow-induced PH, with the potential to identify new treatments for patients with CDH or PAH-CHD.
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Affiliation(s)
- Savas T Tsikis
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Fegan 3, Boston, MA 02115, USA
| | - Timothy Klouda
- Division of Pulmonary Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Thomas I Hirsch
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Fegan 3, Boston, MA 02115, USA
| | - Scott C Fligor
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Fegan 3, Boston, MA 02115, USA
| | - Tiffany Liu
- Division of Pulmonary Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Yunhye Kim
- Division of Pulmonary Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Amy Pan
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Fegan 3, Boston, MA 02115, USA
| | - Mikayla Quigley
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Fegan 3, Boston, MA 02115, USA
| | - Paul D Mitchell
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA 02115, USA
| | - Mark Puder
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Fegan 3, Boston, MA 02115, USA.
| | - Ke Yuan
- Division of Pulmonary Medicine, Boston Children's Hospital, Boston, MA 02115, USA.
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Hsia CCW, Bates JHT, Driehuys B, Fain SB, Goldin JG, Hoffman EA, Hogg JC, Levin DL, Lynch DA, Ochs M, Parraga G, Prisk GK, Smith BM, Tawhai M, Vidal Melo MF, Woods JC, Hopkins SR. Quantitative Imaging Metrics for the Assessment of Pulmonary Pathophysiology: An Official American Thoracic Society and Fleischner Society Joint Workshop Report. Ann Am Thorac Soc 2023; 20:161-195. [PMID: 36723475 PMCID: PMC9989862 DOI: 10.1513/annalsats.202211-915st] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Multiple thoracic imaging modalities have been developed to link structure to function in the diagnosis and monitoring of lung disease. Volumetric computed tomography (CT) renders three-dimensional maps of lung structures and may be combined with positron emission tomography (PET) to obtain dynamic physiological data. Magnetic resonance imaging (MRI) using ultrashort-echo time (UTE) sequences has improved signal detection from lung parenchyma; contrast agents are used to deduce airway function, ventilation-perfusion-diffusion, and mechanics. Proton MRI can measure regional ventilation-perfusion ratio. Quantitative imaging (QI)-derived endpoints have been developed to identify structure-function phenotypes, including air-blood-tissue volume partition, bronchovascular remodeling, emphysema, fibrosis, and textural patterns indicating architectural alteration. Coregistered landmarks on paired images obtained at different lung volumes are used to infer airway caliber, air trapping, gas and blood transport, compliance, and deformation. This document summarizes fundamental "good practice" stereological principles in QI study design and analysis; evaluates technical capabilities and limitations of common imaging modalities; and assesses major QI endpoints regarding underlying assumptions and limitations, ability to detect and stratify heterogeneous, overlapping pathophysiology, and monitor disease progression and therapeutic response, correlated with and complementary to, functional indices. The goal is to promote unbiased quantification and interpretation of in vivo imaging data, compare metrics obtained using different QI modalities to ensure accurate and reproducible metric derivation, and avoid misrepresentation of inferred physiological processes. The role of imaging-based computational modeling in advancing these goals is emphasized. Fundamental principles outlined herein are critical for all forms of QI irrespective of acquisition modality or disease entity.
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Ito Y, Suzuki H, Sasahara Y, Mitsukawa N, Yoshino I. Can surgical repair for pectus excavatum contribute to lung growth? Interact Cardiovasc Thorac Surg 2021; 33:928-934. [PMID: 34423359 DOI: 10.1093/icvts/ivab203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/17/2021] [Accepted: 06/22/2021] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES This study investigates whether the surgical correction of chest deformity is associated with the growth of the lung parenchyma after surgery for pectus excavatum. METHODS Ten patients with pectus excavatum who were treated by the Nuss procedure were examined. The preoperative and postoperative computed tomography (2.5 ± 1.2 years after surgery) scans were performed, and the Haller index, lung volume and lung density were analyzed using a three-dimensional image analysis system (SYNAPSE VINCENT, Fujifilm, Japan). The radiological lung weight was calculated as follows: lung volume (ml) × lung density (g/ml). RESULTS The average age of the 10 patients (men 8; women 2) was 13.8 years (range: 6-26 years). The Haller index was significantly improved from the preoperative value of 5.18 ± 2.20 to the postoperative value of 3.68 ± 1.38 (P = 0.0025). Both the lung volume and weight had significantly increased by 107.1 ± 19.6% and 121.6 ± 11.3%, respectively, after surgery. CONCLUSIONS A significant increase in the weight of the lung after surgical correction suggests that the growth of the lung parenchyma is associated with the correction of chest deformity in younger patients with pectus excavatum.
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Affiliation(s)
- Yuki Ito
- Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Hidemi Suzuki
- Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yoshitaro Sasahara
- Department of Plastic, Reconstructive and Aesthetic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Nobuyuki Mitsukawa
- Department of Plastic, Reconstructive and Aesthetic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Ichiro Yoshino
- Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
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Niedbalski PJ, Cochran AS, Freeman MS, Guo J, Fugate EM, Davis CB, Dahlke J, Quirk JD, Varisco BM, Woods JC, Cleveland ZI. Validating in vivo hyperpolarized 129 Xe diffusion MRI and diffusion morphometry in the mouse lung. Magn Reson Med 2021; 85:2160-2173. [PMID: 33017076 PMCID: PMC8544163 DOI: 10.1002/mrm.28539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/27/2020] [Accepted: 09/14/2020] [Indexed: 02/03/2023]
Abstract
PURPOSE Diffusion and lung morphometry imaging using hyperpolarized gases are promising tools to quantify pulmonary microstructure noninvasively in humans and in animal models. These techniques assume the motion encoded is exclusively diffusive gas displacement, but the impact of cardiac motion on measurements has never been explored. Furthermore, although diffusion morphometry has been validated against histology in humans and mice using 3 He, it has never been validated in mice for 129 Xe. Here, we examine the effect of cardiac motion on diffusion imaging and validate 129 Xe diffusion morphometry in mice. THEORY AND METHODS Mice were imaged using gradient-echo-based diffusion imaging, and apparent diffusion-coefficient (ADC) maps were generated with and without cardiac gating. Diffusion-weighted images were fit to a previously developed theoretical model using Bayesian probability theory, producing morphometric parameters that were compared with conventional histology. RESULTS Cardiac gating had no significant impact on ADC measurements (dual-gating: ADC = 0.020 cm2 /s, single-gating: ADC = 0.020 cm2 /s; P = .38). Diffusion-morphometry-generated maps of ADC (mean, 0.0165 ± 0.0001 cm2 /s) and acinar dimensions (alveolar sleeve depth [h] = 44 µm, acinar duct radii [R] = 99 µm, mean linear intercept [Lm ] = 74 µm) that agreed well with conventional histology (h = 45 µm, R = 108 µm, Lm = 63 µm). CONCLUSION Cardiac motion has negligible impact on 129 Xe ADC measurements in mice, arguing its impact will be similarly minimal in humans, where relative cardiac motion is reduced. Hyperpolarized 129 Xe diffusion morphometry accurately and noninvasively maps the dimensions of lung microstructure, suggesting it can quantify the pulmonary microstructure in mouse models of lung disease.
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Affiliation(s)
- Peter J. Niedbalski
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Alexander S. Cochran
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
| | - Matthew S. Freeman
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
| | - Jinbang Guo
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Elizabeth M. Fugate
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Cory B. Davis
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Physics, West Texas A&M University, Canyon, TX
| | - Jerry Dahlke
- Department of Radiology, Duke University School of Medicine, Durham, NC
| | - James D. Quirk
- Department of Radiology, Washington University, St. Louis, MO
| | - Brian M. Varisco
- Division of Critical Care Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
| | - Jason C. Woods
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Radiology, Washington University, St. Louis, MO
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
| | - Zackary I. Cleveland
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
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Thomen RP, Woods JC, Sturm PF, Jain V, Walkup LL, Higano NS, Quirk JD, Varisco BM. Lung microstructure in adolescent idiopathic scoliosis before and after posterior spinal fusion. PLoS One 2020; 15:e0240265. [PMID: 33031412 PMCID: PMC7544066 DOI: 10.1371/journal.pone.0240265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/22/2020] [Indexed: 11/19/2022] Open
Abstract
Adolescent idiopathic scoliosis (AIS) is associated with decreased respiratory quality of life and impaired diaphragm function. Recent hyperpolarized helium (HHe) MRI studies show alveolarization continues throughout adolescence, and mechanical forces are known to impact alveolarization. We therefore hypothesized that patients with AIS would have alterations in alveolar size, alveolar number, or alveolar septal dimensions compared to adolescents without AIS, and that posterior spinal fusion (PSF) might reverse these differences. We conducted a prospective observational trial using HHe MRI to test for changes in alveolar microstructure in control and AIS subjects at baseline and one year. After obtaining written informed consent from subjects’ legal guardians and assent from the subjects, we performed HHe and proton MRI in 14 AIS and 16 control subjects aged 8–21 years. The mean age of control subjects (12.9 years) was significantly less than AIS (14.9 years, p = 0.003). At baseline, there were no significant differences in alveolar size, number, or alveolar duct morphometry between AIS and control subjects or between the concave (compressed) and convex (expanded) lungs of AIS subjects. At one year after PSF AIS subjects had an increase in alveolar density in the formerly convex lung (p = 0.05), likely reflecting a change in thoracic anatomy, but there were no other significant changes in lung microstructure. Modeling of alveolar size over time demonstrated similar rates of alveolar growth in control and AIS subjects in both right and left lungs pre- and post-PSF. Although this study suffered from poor age-matching, we found no evidence that AIS or PSF impacts lung microstructure. Trial registration: Clinical trial registration number NCT03539770.
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Affiliation(s)
- Robert P. Thomen
- School of Medicine, University of Missouri, Columbia, Missouri, United States of America
- Division of Radiology, University of Missouri, Columbia, Missouri, United States of America
| | - Jason C. Woods
- College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Pulmonary Medicine, Cincinnati Children’s Hospital, Cincinnati, Ohio, United States of America
| | - Peter F. Sturm
- College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Orthopaedics, Cincinnati Children’s Hospital, Cincinnati, Ohio, United States of America
| | - Viral Jain
- College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Orthopaedics, Cincinnati Children’s Hospital, Cincinnati, Ohio, United States of America
| | - Laura L. Walkup
- Pulmonary Medicine, Cincinnati Children’s Hospital, Cincinnati, Ohio, United States of America
| | - Nara S. Higano
- Pulmonary Medicine, Cincinnati Children’s Hospital, Cincinnati, Ohio, United States of America
| | - James D. Quirk
- Mallincrodt Institute of Radiology, Washington University, St. Louis, MO, United States of America
- School of Medicine, Washington University, St. Louis, MO, United States of America
| | - Brian M. Varisco
- College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Critical Care Medicine, Cincinnati Children’s Hospital, Cincinnati, Ohio, United States of America
- * E-mail:
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Application of a stretched-exponential model for morphometric analysis of accelerated diffusion-weighted 129Xe MRI of the rat lung. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2020; 34:73-84. [PMID: 32632748 DOI: 10.1007/s10334-020-00860-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/10/2020] [Accepted: 06/19/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Diffusion-weighted, hyperpolarized 129Xe MRI is useful for the characterization of microstructural changes in the lung. A stretched exponential model was proposed for morphometric extraction of the mean chord length (Lm) from diffusion-weighted data. The stretched exponential model enables accelerated mapping of Lm in a single-breathhold using compressed sensing. Our purpose was to compare Lm maps obtained from stretched-exponential model analysis of accelerated versus unaccelerated diffusion-weighted 129Xe MRI data obtained from healthy/injured rat lungs. MATERIAL AND METHODS Lm maps were generated using a stretched-exponential model analysis of previously acquired fully sampled diffusion-weighted 129Xe rat data (b values = 0 … 110 s/cm2) and compared to Lm maps generated from retrospectively undersampled data simulating acceleration factors of 7/10. The data included four control rats and five rats receiving whole-lung irradiation to mimic radiation-induced lung injury. Mean Lm obtained from the accelerated/unaccelerated maps were compared to histological mean linear intercept. RESULTS Accelerated Lm estimates were similar to unaccelerated Lm estimates in all rats, and similar to those previously reported (< 12% different). Lm was significantly reduced (p < 0.001) in the irradiated rat cohort (90 ± 20 µm/90 ± 20 µm) compared to the control rats (110 ± 20 µm/100 ± 15 µm) and agreed well with histological mean linear intercept. DISCUSSION Accelerated mapping of Lm using a stretched-exponential model analysis is feasible, accurate and agrees with histological mean linear intercept. Acceleration reduces scan time, thus should be considered for the characterization of lung microstructural changes in humans where breath-hold duration is short.
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Messerli M, Aaldijk D, Haberthür D, Röss H, García-Poyatos C, Sande-Melón M, Khoma OZ, Wieland FAM, Fark S, Djonov V. Adaptation mechanism of the adult zebrafish respiratory organ to endurance training. PLoS One 2020; 15:e0228333. [PMID: 32023296 PMCID: PMC7001924 DOI: 10.1371/journal.pone.0228333] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/13/2020] [Indexed: 11/19/2022] Open
Abstract
In order to study the adaptation scope of the fish respiratory organ and the O2 metabolism due to endurance training, we subjected adult zebrafish (Danio rerio) to endurance exercise for 5 weeks. After the training period, the swimmer group showed a significant increase in swimming performance, body weight and length. In scanning electron microscopy of the gills, the average length of centrally located primary filaments appeared significantly longer in the swimmer than in the non-trained control group (+6.1%, 1639 μm vs. 1545 μm, p = 0.00043) and the average number of secondary filaments increased significantly (+7.7%, 49.27 vs. 45.73, p = 9e-09). Micro-computed tomography indicated a significant increase in the gill volume (p = 0.048) by 11.8% from 0.490 mm3 to 0.549 mm3. The space-filling complexity dropped significantly (p = 0.0088) by 8.2% from 38.8% to 35.9%., i.e. making the gills of the swimmers less compact. Respirometry after 5 weeks showed a significantly higher oxygen consumption (+30.4%, p = 0.0081) of trained fish during exercise compared to controls. Scanning electron microscopy revealed different stages of new secondary filament budding, which happened at the tip of the primary lamellae. Using BrdU we could confirm that the growth of the secondary filaments took place mainly in the distal half and the tip and for primary filaments mainly at the tip. We conclude that the zebrafish respiratory organ-unlike the mammalian lung-has a high plasticity, and after endurance training increases its volume and changes its structure in order to facilitate O2 uptake.
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Affiliation(s)
- Matthias Messerli
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Dea Aaldijk
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - David Haberthür
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Helena Röss
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Carolina García-Poyatos
- Developmental Biology and Regeneration, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Marcos Sande-Melón
- Developmental Biology and Regeneration, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Oleksiy-Zakhar Khoma
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Fluri A. M. Wieland
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Sarya Fark
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Valentin Djonov
- Topographic and clinical Anatomy, Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
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9
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Wakamatsu I, Matsuguma H, Nakahara R, Chida M. Factors associated with compensatory lung growth after pulmonary lobectomy for lung malignancy: an analysis of lung weight and lung volume changes based on computed tomography findings. Surg Today 2019; 50:144-152. [PMID: 31440912 DOI: 10.1007/s00595-019-01863-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 07/15/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE To establish the factors associated with compensatory lung growth (CLG) in human adults. METHODS The subjects of this study were 216 patients who underwent pulmonary lobectomy between January 2008 and March 2015 and had computed tomography (CT) scans done before and 2 years after surgery with no signs of recurrence. The predicted postoperative values of lung volume and lung weight, based on the preoperative CT data, were compared with those 2 years after surgery. RESULTS When the predicted postoperative values were considered to be 100%, the mean lung volume and lung weight 2 years after surgery were 116 ± 16% and 115 ± 19%, respectively. CLG was defined as both lung volume ≥ 110% and lung weight ≥ 106% (CLG group; n = 108). Both univariate and multivariate analyses showed that younger age (≤ 60 years), a larger number of resected subsegments (≥ 10), and a light- (< 20 pack-years) or non-smoking history were significantly associated with CLG. CONCLUSIONS This study identified younger age, a light- or non-smoking history, and a large resection volume as the predictors of CLG in patients who underwent pulmonary lobectomy for lung malignancy. All of these three factors may be reasonably connected to CLG.
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Affiliation(s)
- Ikuma Wakamatsu
- Division of Thoracic Surgery, Tochigi Cancer Center, 4-9-13 Yohnan, Utsunomiya, 320-0834, Tochigi, Japan.
| | - Haruhisa Matsuguma
- Division of Thoracic Surgery, Tochigi Cancer Center, 4-9-13 Yohnan, Utsunomiya, 320-0834, Tochigi, Japan
| | - Rie Nakahara
- Division of Thoracic Surgery, Tochigi Cancer Center, 4-9-13 Yohnan, Utsunomiya, 320-0834, Tochigi, Japan
| | - Masayuki Chida
- Department of General Thoracic Surgery, Dokkyo Medical University, Mibu, Tochigi, Japan
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10
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Westcott A, McCormack DG, Parraga G, Ouriadov A. Advanced pulmonary MRI to quantify alveolar and acinar duct abnormalities: Current status and future clinical applications. J Magn Reson Imaging 2019; 50:28-40. [PMID: 30637857 DOI: 10.1002/jmri.26623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 12/23/2022] Open
Abstract
There are serious clinical gaps in our understanding of chronic lung disease that require novel, sensitive, and noninvasive in vivo measurements of the lung parenchyma to measure disease pathogenesis and progressive changes over time as well as response to treatment. Until recently, our knowledge and appreciation of the tissue changes that accompany lung disease has depended on ex vivo biopsy and concomitant histological and stereological measurements. These measurements have revealed the underlying pathologies that drive lung disease and have provided important observations about airway occlusion, obliteration of the terminal bronchioles and airspace enlargement, or fibrosis and their roles in disease initiation and progression. ex vivo tissue stereology and histology are the established gold standards and, more recently, micro-computed tomography (CT) measurements of ex vivo tissue samples has also been employed to reveal new mechanistic findings about the progression of obstructive lung disease in patients. While these approaches have provided important understandings using ex vivo analysis of excised samples, recently developed hyperpolarized noble gas MRI methods provide an opportunity to noninvasively measure acinar duct and terminal airway dimensions and geometry in vivo, and, without radiation burden. Therefore, in this review we summarize emerging pulmonary MRI morphometry methods that provide noninvasive in vivo measurements of the lung in patients with bronchopulmonary dysplasia and chronic obstructive pulmonary disease, among others. We discuss new findings, future research directions, as well as clinical opportunities to address current gaps in patient care and for testing of new therapies. Level of Evidence: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:28-40.
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Affiliation(s)
- Andrew Westcott
- Robarts Research Institute, University of Western Ontario, London, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Canada
| | - David G McCormack
- Division of Respirology, Department of Medicine, University of Western Ontario, London, Canada
| | - Grace Parraga
- Robarts Research Institute, University of Western Ontario, London, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Canada.,Division of Respirology, Department of Medicine, University of Western Ontario, London, Canada
| | - Alexei Ouriadov
- Department of Physics and Astronomy, University of Western Ontario, London, Canada
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11
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Woods JC, Conradi MS. 3He diffusion MRI in human lungs. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 292:90-98. [PMID: 29705031 PMCID: PMC6386180 DOI: 10.1016/j.jmr.2018.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 03/05/2018] [Accepted: 04/11/2018] [Indexed: 06/08/2023]
Abstract
Hyperpolarized 3He gas allows the air spaces of the lungs to be imaged via MRI. Imaging of restricted diffusion is addressed here, which allows the microstructure of the lung to be characterized through the physical restrictions to gas diffusion presented by airway and alveolar walls in the lung. Measurements of the apparent diffusion coefficient (ADC) of 3He at time scales of milliseconds and seconds are compared; measurement of acinar airway sizes by determination of the microscopic anisotropy of diffusion is discussed. This is where Dr. JJH Ackerman's influence was greatest in aiding the formation of the Washington University 3He group, involving early a combination of physicists, radiologists, and surgeons, as the first applications of 3He ADC were to COPD and its destruction/modification of lung microstructure via emphysema. The sensitivity of the method to early COPD is demonstrated, as is its validation by direct comparison to histology. More recently the method has been used broadly in adult and pediatric obstructive lung diseases, from severe asthma to cystic fibrosis to bronchopulmonary dysplasia, a result of premature birth. These applications of the technique are discussed briefly.
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Affiliation(s)
- Jason C Woods
- Center for Pulmonary Imaging Research, Departments of Radiology and Pediatrics (Pulmonary Medicine), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, ML 5033, Cincinnati, OH 45229, USA; Department of Physics, Washington University, One Brookings Drive, CB 1105, St Louis, MO 63130, USA.
| | - Mark S Conradi
- ABQMR, Inc., 2301 Yale Blvd. SE, Suite C2, Albuquerque, NM 87106, USA; Department of Physics, Washington University, One Brookings Drive, CB 1105, St Louis, MO 63130, USA.
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12
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Alvira CM, Morty RE. Can We Understand the Pathobiology of Bronchopulmonary Dysplasia? J Pediatr 2017; 190:27-37. [PMID: 29144252 PMCID: PMC5726414 DOI: 10.1016/j.jpeds.2017.08.041] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/28/2017] [Accepted: 08/16/2017] [Indexed: 01/17/2023]
Affiliation(s)
- Cristina M. Alvira
- Center for Excellence in Pulmonary Biology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, California 94305
| | - Rory E. Morty
- Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center campus of the German Center for Lung Research, Giessen, Germany,Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
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13
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Joshi R, Liu S, Brown MD, Young SM, Batie M, Kofron JM, Xu Y, Weaver TE, Apsley K, Varisco BM. Stretch regulates expression and binding of chymotrypsin-like elastase 1 in the postnatal lung. FASEB J 2016; 30:590-600. [PMID: 26443822 PMCID: PMC6994241 DOI: 10.1096/fj.15-277350] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/21/2015] [Indexed: 12/23/2022]
Abstract
Lung stretch is critical for normal lung development and for compensatory lung growth after pneumonectomy (PNX), but the mechanisms by which strain induces matrix remodeling are unclear. Our prior work demonstrated an association of chymotrypsin-like elastase 1 (Cela1) with lung elastin remodeling, and that strain triggered a near-instantaneous elastin-remodeling response. We sought to determine whether stretch regulates Cela1 expression and Cela1 binding to lung elastin. In C57BL/6J mice, Cela1 protein increased 176-fold during lung morphogenesis. Cela1 was covalently bound to serpin peptidase inhibitor, clade A, member 1, resulting in a higher molecular mass in lung homogenate compared to pancreas homogenate. Post-PNX, Cela1 mRNA increased 6-fold, protein 3-fold, and Cela1-positive cells 2-fold. Cela1 was expressed predominantly in alveolar type II cells in the embryonic lung and predominantly in CD90-positive lung fibroblasts postnatally. During compensatory lung growth, Cela1 expression was induced in nonproliferative mesenchymal cells. In ex vivo mouse lung sections, stretch increased Cela1 binding to lung tissue by 46%. Competitive inhibition with soluble elastin completely abrogated this increase. Areas of stretch-induced elastase activity and Cela1 binding colocalized. The stretch-dependent expression and binding kinetics of Cela1 indicate an important role in stretch-dependent remodeling of the peripheral lung during development and regeneration.
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Affiliation(s)
- Rashika Joshi
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Sheng Liu
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Montell D Brown
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Sarah M Young
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Matthew Batie
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - J Matthew Kofron
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Yan Xu
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Timmothy E Weaver
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Karen Apsley
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Brian M Varisco
- *Division of Critical Care Medicine, Division of Developmental Biology, and Division of Pulmonary Biology, Department of Clinical Engineering, and Biomedical Research Internship for Minority Students Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; and Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
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14
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Abstract
Imaging has played a vital role in the clinical assessment of bronchopulmonary dysplasia (BPD) since its first recognition. In this review, how chest radiograph, computerized tomography (CT), nuclear medicine, and MRI have contributed to the understanding of BPD pathology and how emerging advancements in these methods, including low-dose and quantitative CT, sophisticated proton and hyperpolarized-gas MRI, influence the future of BPD imaging are discussed.
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Affiliation(s)
- Laura L Walkup
- Division of Pulmonary Medicine, Department of Radiology, Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MC 5033, Cincinnati, OH 42229, USA
| | - Jason C Woods
- Division of Pulmonary Medicine, Department of Radiology, Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MC 5033, Cincinnati, OH 42229, USA.
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15
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Mühlfeld C, Hegermann J, Wrede C, Ochs M. A review of recent developments and applications of morphometry/stereology in lung research. Am J Physiol Lung Cell Mol Physiol 2015; 309:L526-36. [DOI: 10.1152/ajplung.00047.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 07/09/2015] [Indexed: 11/22/2022] Open
Abstract
Design-based stereology is the gold standard of morphometry in lung research. Here, we analyze the current use of morphometric and stereological methods in lung research and provide an overview on recent methodological developments and biological observations made by the use of stereology. Based on this analysis we hope to provide useful recommendations for a good stereological practice to further the use of advanced and unbiased stereological methods.
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Affiliation(s)
- Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; and
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
| | - Jan Hegermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; and
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
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16
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Ouriadov A, Fox M, Hegarty E, Parraga G, Wong E, Santyr GE. Early stage radiation-induced lung injury detected using hyperpolarized (129) Xe Morphometry: Proof-of-concept demonstration in a rat model. Magn Reson Med 2015; 75:2421-31. [PMID: 26154889 DOI: 10.1002/mrm.25825] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 05/27/2015] [Accepted: 06/08/2015] [Indexed: 11/08/2022]
Abstract
PURPOSE Radiation-induced lung injury (RILI) is still the major dose-limiting toxicity related to lung cancer radiation therapy, and it is difficult to predict and detect patients who are at early risk of severe pneumonitis and fibrosis. The goal of this proof-of-concept preclinical demonstration was to investigate the potential of hyperpolarized (129) Xe diffusion-weighted MRI to detect the lung morphological changes associated with early stage RILI. METHODS Hyperpolarized (129) Xe MRI was performed using eight different diffusion sensitizations (0.0-115 s/cm(2) ) in a small group of control rats (n = 4) and rats 2 wk after radiation exposure (n = 5). The diffusion-weighted images were used to obtain morphological estimates of the pulmonary parenchyma including external radius (R), internal radius (r), alveolar sleeve depth (h), and mean airspace chord length (Lm ). The histological mean linear intercept (MLI) were obtained for five control and five irradiated animals. RESULTS Mean R, r, and Lm were both significantly different (P < 0.02) in the irradiated rats (74 ± 17 µm, 43 ± 12 µm, and 54 ± 17 µm, respectively) compared with the control rats (100 ± 12 µm, 67 ± 10 µm, and 79 ± 12 µm, respectively). Changes in measured Lm values were consistent with changes in MLI values observed by histology. CONCLUSIONS Hyperpolarized (129) Xe MRI provides a way to detect and measure regional microanatomical changes in lung parenchyma in a preclinical model of RILI. Magn Reson Med 75:2421-2431, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Alexei Ouriadov
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada
| | - Matthew Fox
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Elaine Hegarty
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada
| | - Grace Parraga
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Eugene Wong
- Department of Medical Biophysics, Western University, London, Ontario, Canada.,Department of Physics and Astronomy, Western University, London, Ontario, Canada
| | - Giles E Santyr
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada.,Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
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17
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Young SM, Liu S, Joshi R, Batie MR, Kofron M, Guo J, Woods JC, Varisco BM. Localization and stretch-dependence of lung elastase activity in development and compensatory growth. J Appl Physiol (1985) 2015; 118:921-31. [PMID: 25614601 DOI: 10.1152/japplphysiol.00954.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 01/20/2015] [Indexed: 01/08/2023] Open
Abstract
Synthesis and remodeling of the lung matrix is necessary for primary and compensatory lung growth. Because cyclic negative force is applied to developing lung tissue during the respiratory cycle, we hypothesized that stretch is a critical regulator of lung matrix remodeling. By using quantitative image analysis of whole-lung and whole-lobe elastin in situ zymography images, we demonstrated that elastase activity increased twofold during the alveolar stage of postnatal lung morphogenesis in the mouse. Remodeling was restricted to alveolar walls and ducts and was nearly absent in dense elastin band structures. In the mouse pneumonectomy model of compensatory lung growth, elastase activity increased threefold, peaking at 14 days postpneumonectomy and was higher in the accessory lobe compared with other lobes. Remodeling during normal development and during compensatory lung growth was different with increased major airway and pulmonary arterial remodeling during development but not regeneration, and with homogenous remodeling throughout the parenchyma during development, but increased remodeling only in subpleural regions during compensatory lung growth. Left lung wax plombage prevented increased lung elastin during compensatory lung growth. To test whether the adult lung retains an innate capacity to remodel elastin, we developed a confocal microscope-compatible stretching device. In ex vivo adult mouse lung sections, lung elastase activity increased exponentially with strain and in peripheral regions of lung more than in central regions. Our study demonstrates that lung elastase activity is stretch-dependent and supports a model in which externally applied forces influence the composition, structure, and function of the matrix during periods of alveolar septation.
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Affiliation(s)
- Sarah Marie Young
- College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Sheng Liu
- Division of Critical Care Medicine, Cincinnati Children's Hospital, Cincinnati, Ohio; Department of Pediatrics, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Rashika Joshi
- Division of Critical Care Medicine, Cincinnati Children's Hospital, Cincinnati, Ohio; Department of Pediatrics, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Matthew R Batie
- Clinical Engineering, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Matthew Kofron
- Department of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Jinbang Guo
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Jason C Woods
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital, Cincinnati, Ohio; Department of Radiology, Cincinnati Children's Hospital, Cincinnati, Ohio; and Department of Pediatrics, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Brian Michael Varisco
- Division of Critical Care Medicine, Cincinnati Children's Hospital, Cincinnati, Ohio; Department of Pediatrics, Cincinnati Children's Hospital, Cincinnati, Ohio
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18
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Abstract
In humans, disrupted repair and remodeling of injured lung contributes to a host of acute and chronic lung disorders which may ultimately lead to disability or death. Injury-based animal models of lung repair and regeneration are limited by injury-specific responses making it difficult to differentiate changes related to the injury response and injury resolution from changes related to lung repair and lung regeneration. However, use of animal models to identify these repair and regeneration signaling pathways is critical to the development of new therapies aimed at improving pulmonary function following lung injury. The mouse pneumonectomy model utilizes compensatory lung growth to isolate those repair and regeneration signals in order to more clearly define mechanisms of alveolar re-septation. Here, we describe our technique for performing mouse pneumonectomy and sham pneumonectomy. This technique may be utilized in conjunction with lineage tracing or other transgenic mouse models to define molecular and cellular mechanism of lung repair and regeneration.
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Affiliation(s)
- Sheng Liu
- Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center
| | - Jeffrey Cimprich
- Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center
| | - Brian M Varisco
- Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center;
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19
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Walkup LL, Woods JC. Translational applications of hyperpolarized 3He and 129Xe. NMR IN BIOMEDICINE 2014; 27:1429-1438. [PMID: 24953709 DOI: 10.1002/nbm.3151] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 04/07/2014] [Accepted: 05/19/2014] [Indexed: 06/03/2023]
Abstract
Clinical magnetic resonance imaging of the lung is technologically challenging, yet over the past two decades hyperpolarized noble gas ((3)He and (129)Xe) imaging has demonstrated the ability to measure multiple pulmonary functional biomarkers. There is a growing need for non-ionizing, non-invasive imaging techniques due to increased concern about cancer risk from ionizing radiation, but the translation of hyperpolarized gas imaging to the pulmonary clinic has been stunted by limited access to the technology. New developments may open doors to greater access and more translation to clinical studies. Here we briefly review a few translational applications of hyperpolarized gas MRI in the contexts of ventilation, diffusion, and dissolved-phase imaging, as well as comparing and contrasting (3)He and (129)Xe gases for these applications. Simple static ventilation MRI reveals regions of the lung not participating in normal ventilation, and these defects have been observed in many pulmonary diseases. Biomarkers related to airspace size and connectivity can be quantified by apparent diffusion coefficient measurements of hyperpolarized gas, and have been shown to be more sensitive to small changes in lung morphology than standard clinical pulmonary functional tests and have been validated by quantitative histology. Parameters related to gas uptake and exchange and lung tissue density can be determined using (129)Xe dissolved-phase MRI. In most cases functional biomarkers can be determined via MRI of either gas, but for some applications one gas may be preferred, such as (3)He for long-range diffusion measurements and (129)Xe for dissolved-phase imaging. Greater access to hyperpolarized gas imaging coupled with newly developing therapeutics makes pulmonary medicine poised for a potential revolution, further adding to the prospects of personalized medicine already evidenced by advancements in molecular biology. Hyperpolarized gas researchers have the opportunity to contribute to this revolution, particularly if greater clinical application of hyperpolarized gas imaging is realized.
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Affiliation(s)
- Laura L Walkup
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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20
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Guo J, Huang HJ, Wang X, Wang W, Ellison H, Thomen RP, Gelman AE, Woods JC. Imaging mouse lung allograft rejection with (1)H MRI. Magn Reson Med 2014; 73:1970-8. [PMID: 24954886 DOI: 10.1002/mrm.25313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 05/05/2014] [Accepted: 05/18/2014] [Indexed: 12/24/2022]
Abstract
PURPOSE To demonstrate that longitudinal, noninvasive monitoring via MRI can characterize acute cellular rejection in mouse orthotopic lung allografts. METHODS Nineteen Balb/c donor to C57BL/6 recipient orthotopic left lung transplants were performed, further divided into control-Ig versus anti-CD4/anti-CD8 treated groups. A two-dimensional multislice gradient-echo pulse sequence synchronized with ventilation was used on a small-animal MR scanner to acquire proton images of lung at postoperative days 3, 7, and 14, just before sacrifice. Lung volume and parenchymal signal were measured, and lung compliance was calculated as volume change per pressure difference between high and low pressures. RESULTS Normalized parenchymal signal in the control-Ig allograft increased over time, with statistical significance between day 14 and day 3 posttransplantation (0.046→0.789; P < 0.05), despite large intermouse variations; this was consistent with histopathologic evidence of rejection. Compliance of the control-Ig allograft decreased significantly over time (0.013→0.003; P < 0.05), but remained constant in mice treated with anti-CD4/anti-CD8 antibodies. CONCLUSION Lung allograft rejection in individual mice can be monitored by lung parenchymal signal changes and by lung compliance through MRI. Longitudinal imaging can help us better understand the time course of individual lung allograft rejection and response to treatment.
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Affiliation(s)
- Jinbang Guo
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; Department of Physics, Washington University in St. Louis, St. Louis, Missouri, USA
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21
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Zamora IJ, Sheikh F, Olutoye OO, Cassady CI, Lee TC, Ruano R, Cass DL. Mainstem bronchial atresia: a lethal anomaly amenable to fetal surgical treatment. J Pediatr Surg 2014; 49:706-11. [PMID: 24851752 DOI: 10.1016/j.jpedsurg.2014.02.051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 02/13/2014] [Indexed: 12/25/2022]
Abstract
PURPOSE The purpose of this study was to review the unique imaging characteristics, prenatal course, and outcomes for fetuses with mainstem bronchial atresia (MBA). METHODS The records of all patients referred for a fetal lung malformation from 2001 to 2012 and the medical literature were reviewed to identify cases of MBA. RESULTS Of 129 fetuses evaluated, 3 were diagnosed prenatally with right-sided MBA. The first had a CCAM-volume ratio (CVR) of 9, hydrops, mirror syndrome, and preterm delivery of a nonviable fetus. The second (CVR 2.6) had ascites, preterm delivery at 34-weeks, and neonatal demise. The third fetus (CVR 5.7) presented with hydrops at 21-weeks, prompting fetal pneumonectomy. Postoperatively, hydrops resolved, and the contralateral lung grew dramatically, but preterm delivery occurred 3 weeks later. Ventilation could not be sustained, and the infant died. Four similar cases of MBA were in the literature, all right-sided. Two fetuses with hydrops delivered at 25-weeks and died immediately. One pregnancy was terminated. One fetus underwent pneumonectomy at 24-weeks but died intraoperatively. CONCLUSION MBA is a rare and lethal lesion that must be distinguished from other right-sided lung masses. Fetal pneumonectomy can be performed with resolution of hydrops and compensatory contralateral lung growth, but remains limited by complications of preterm birth.
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Affiliation(s)
- Irving J Zamora
- Texas Children's Fetal Center, Texas Children's Hospital, Houston, TX; Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Fariha Sheikh
- Texas Children's Fetal Center, Texas Children's Hospital, Houston, TX; Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Oluyinka O Olutoye
- Texas Children's Fetal Center, Texas Children's Hospital, Houston, TX; Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX; Department Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX
| | - Christopher I Cassady
- Texas Children's Fetal Center, Texas Children's Hospital, Houston, TX; Department of Radiology, Baylor College of Medicine, Houston, TX
| | - Timothy C Lee
- Texas Children's Fetal Center, Texas Children's Hospital, Houston, TX; Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Rodrigo Ruano
- Texas Children's Fetal Center, Texas Children's Hospital, Houston, TX; Department Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX
| | - Darrell L Cass
- Texas Children's Fetal Center, Texas Children's Hospital, Houston, TX; Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX; Department Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX.
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22
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Thane K, Ingenito EP, Hoffman AM. Lung regeneration and translational implications of the postpneumonectomy model. Transl Res 2014; 163:363-76. [PMID: 24316173 DOI: 10.1016/j.trsl.2013.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/30/2013] [Accepted: 11/18/2013] [Indexed: 10/26/2022]
Abstract
Lung regeneration research is yielding data with increasing translational value. The classical models of lung development, postnatal alveolarization, and postpneumonectomy alveolarization have contributed to a broader understanding of the cellular participants including stem-progenitor cells, cell-cell signaling pathways, and the roles of mechanical deformation and other physiologic factors that have the potential to be modulated in human and animal patients. Although recent information is available describing the lineage fate of lung fibroblasts, genetic fate mapping, and clonal studies are lacking in the study of lung regeneration and deserve further examination. In addition to increasing knowledge concerning classical alveolarization (postnatal, postpneumonectomy), there is increasing evidence for remodeling of the adult lung after partial pneumonectomy. Though limited in scope, compelling data have emerged describing restoration of lung tissue mass in the adult human and in large animal models. The basis for this long-term adaptation to pneumonectomy is poorly understood, but investigations into mechanisms of lung regeneration in older animals that have lost their capacity for rapid re-alveolarization are warranted, as there would be great translational value in modulating these mechanisms. In addition, quantitative morphometric analysis has progressed in conjunction with developments in advanced imaging, which allow for longitudinal and nonterminal evaluation of pulmonary regenerative responses in animals and humans. This review focuses on the cellular and molecular events that have been observed in animals and humans after pneumonectomy because this model is closest to classical regeneration in other mammalian systems and has revealed several new fronts of translational research that deserve consideration.
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Affiliation(s)
- Kristen Thane
- Department of Clinical Sciences, Regenerative Medicine Laboratory, Tufts University Cummings School of Veterinary Medicine, North Grafton, Mass
| | - Edward P Ingenito
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brigham and Women's Hospital, Boston, Mass
| | - Andrew M Hoffman
- Department of Clinical Sciences, Regenerative Medicine Laboratory, Tufts University Cummings School of Veterinary Medicine, North Grafton, Mass.
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23
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Madurga A, Mizíková I, Ruiz-Camp J, Morty RE. Recent advances in late lung development and the pathogenesis of bronchopulmonary dysplasia. Am J Physiol Lung Cell Mol Physiol 2013; 305:L893-905. [PMID: 24213917 DOI: 10.1152/ajplung.00267.2013] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In contrast to early lung development, a process exemplified by the branching of the developing airways, the later development of the immature lung remains very poorly understood. A key event in late lung development is secondary septation, in which secondary septa arise from primary septa, creating a greater number of alveoli of a smaller size, which dramatically expands the surface area over which gas exchange can take place. Secondary septation, together with architectural changes to the vascular structure of the lung that minimize the distance between the inspired air and the blood, are the objectives of late lung development. The process of late lung development is disturbed in bronchopulmonary dysplasia (BPD), a disease of prematurely born infants in which the structural development of the alveoli is blunted as a consequence of inflammation, volutrauma, and oxygen toxicity. This review aims to highlight notable recent developments in our understanding of late lung development and the pathogenesis of BPD.
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Affiliation(s)
- Alicia Madurga
- Dept. of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Parkstrasse 1, D-61231 Bad Nauheim, Germany.
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