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Pulmonary "air leaks," typically the result of pleural injury caused by lung surgery or chest trauma, result in the accumulation of air in the pleural space (pneumothorax). Air leaks are a major source of morbidity and prolonged hospitalization after pulmonary surgery. Previous work has demonstrated structural heteropolysaccharide (pectin) binding to the mouse pleural glycocalyx. The similar lectin-binding characteristics and ultrastructural features of the human and mouse pleural glycocalyx suggested the potential application of these polymers in humans. To investigate the utility of pectin-based polymers, we developed a simulacrum using freshly obtained human pleura. Pressure-decay leak testing was performed with an inflation maneuver that involved a 3 s ramp to a 3 s plateau pressure; the inflation was completely abrogated after needle perforation of the pleura. Using nonbiologic materials, pressure-decay leak testing demonstrated an exponential decay with a plateau phase in materials with a Young's modulus less than 5. In human pleural testing, the simulacrum was used to test the sealant function of four mixtures of pectin-based polymers. A 50% high-methoxyl pectin and 50% carboxymethylcellulose mixture demonstrated no sealant failures at transpleural pressures of 60 cmH2 O. In contrast, pectin mixtures containing 50% low-methoxyl pectin, 50% amidated low-methoxyl pectins, or 100% carboxymethylcellulose demonstrated frequent sealant failures at transpleural pressures of 40-50 cmH2 O (p

A contribution of pulmonary blood distension to alveolar opening was first proposed more than 100 years ago. To investigate the contribution of blood distension to lung mechanics, we studied control mice (normal perfusion), mice after exsanguination (absent perfusion) and mice after varying degrees of parenchymal resection (supra-normal perfusion). On inflation, mean tracheal pressures were higher in the bloodless mouse (4.0α2.5 cmH2O); however, there was minimal difference between conditions on deflation (0.7α0.9 cmH2O). To separate the peripheral and central mechanical effects of blood volume, multi-frequency lung impedance data was fitted to the constant-phase model. The presence or absence of blood had no effect on central airway resistance (p>.05). In contrast, measures of tissue damping (G), tissue elastance (H) and hysteresivity (η) demonstrated a significant increase in bloodless mice relative to control mice (p

In many mammals, including humans, removal of one lung (pneumonectomy) results in the compensatory growth of the remaining lung. Compensatory growth involves not only an increase in lung size, but also an increase in the number of alveoli in the peripheral lung; however, the process of compensatory neoalveolarization remains poorly understood. Here, we show that the expression of α-smooth muscle actin (SMA)—a cytoplasmic protein characteristic of myofibroblasts—is induced in the pleura following pneumonectomy. SMA induction appears to be dependent on pleural deformation (stretch) as induction is prevented by plombage or phrenic nerve transection (P < 0.001). Within 3 days of pneumonectomy, the frequency of SMA⁺ cells in subpleural alveolar ducts was significantly increased (P < 0.01). To determine the functional activity of these SMA⁺ cells, we isolated regenerating alveolar ducts by laser microdissection and analyzed individual cells using microfluidic single-cell quantitative PCR. Single cells expressing the SMA (Acta2) gene demonstrated significantly greater transcriptional activity than endothelial cells or other discrete cell populations in the alveolar duct (P < 0.05). The transcriptional activity of the Acta2⁺ cells, including expression of TGF signaling as well as repair-related genes, suggests that these myofibroblast-like cells contribute to compensatory lung growth. Keywords: compensatory growth; gene expression; lung; myofibroblasts, National Institutes of Health (U.S.) (Grant HL94567), National Institutes of Health (U.S.) (Grant CA009535), National Institutes of Health (U.S.) (Grant ES000002)

Objectives: The mesothelium, the surface layer of the heart, lung, bowel, liver and tunica vaginalis, is a complex tissue implicated in organ-specific diseases and regenerative biology; however, the mechanism of mesothelial repair after surgical injury is unknown. Previous observations indicated seeding of denuded mesothelium by free-floating mesothelial cells may contribute to mesothelial healing. In this study, we investigated the prevalence of mesothelial cells in pleural fluid during the 7 days following pulmonary surgery. Study design: Flow cytometry was employed to study pleural fluid of 45 patients after lung resection or transplantation. We used histologically validated mesothelial markers (CD71 and WT1) to estimate the prevalence of mesothelial cells. Results: The viability of pleural fluid cells approached 100%. Leukocytes and mesothelial cells were identified in the pleural fluid within the first week after surgery. The leukocyte concentration was relatively stable at all time points. In contrast, mesothelial cells, identified by CD71 and WT1 peaked on POD3. The broad expression of CD71 molecule in postoperative pleural fluid suggests that many of the free-floating non-leukocyte cells were activated or proliferative mesothelial cells. Conclusion: We demonstrated that pleural fluid post lung surgery is a source of mesothelial cells; most of these cells appear to be viable and, as shown by CD71 staining, activated mesothelial cells. The observed peak of mesothelial cells on POD3 is consistent with a potential reparative role of free-floating mesothelial cells after pulmonary surgery.

[EN] Continuous exposures to ultraviolet radiation can lead to harmful effects on human skin. Professional drivers may spend more than 8 h per day inside a vehicle. This study describes an analysis of the UVER (erythemal ultraviolet radiation) received by a driver and passenger inside a vehicle. A three-door Peugeot 206 was used for the study. VioSpor Blue Line dosimeters (with a response profile close to that of human skin) were used to measure the erythematic dose of UV radiation (able to produce erythema on human skin). Four dosimeters were placed in the driver¿s position and another four in the passenger¿s position. Daily irradiance was analyzed for a day in April using PMA radiometers. The measurements were obtained on relatively clear days from February to December 2009 between 9:30 A.M. and 3 P.M. Additionally, a prediction was made of the time required to produce an erythema on the driver¿s skin. UVER exposure, in some of the driver¿s positions, exceeds the Exposure Limits given by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Skin protection measures should be taken into account by professional drivers to prevent the harmful effects of UVER radiation., This work was carried out with financing from the Ministry of Economy and Competitiveness, Project CGL2010-15931/CLI, from the Generalitat Valenciana within the PROMETEO/2010/064 Project, and the Spanish Ministry of Science and Innovation, in the CGL200761813 Project.

This study examined 420 veterans and service members to assess their receptiveness toward complementary and alternative medicine (CAM). Overall findings indicated veterans and service members did not have adequate knowledge of all CAM techniques; however, only 12.8% of respondents indicated disinterest in participating in CAM after being given a brief description of the benefits of specific alternative medicine techniques. Furthermore, the perceptions and preferences among the participants were examined in relation to receiving counseling. Subsequently, differences in gender, presence of a mental health diagnosis, mood difficulties (e.g., quick to get angry), area of life difficulties (e.g., isolation from friends and family), education, ethnicity, and time since discharge were examined to assess for predictive factors that may contribute to interest in engaging in CAM. Implications for rehabilitation practice, education, and research are discussed.

The axial connective tissue system is a fiber continuum of the lung that maintains alveolar surface area during changes in lung volume. Although the molecular anatomy of the axial system remains undefined, the fiber continuum of the lung is central to contemporary models of lung micromechanics and alveolar regeneration. To provide a detailed molecular structure of the axial connective tissue system, we examined the extracellular matrix of murine lungs. The lungs were decellularized using a 24 hr detergent treatment protocol. Systematic evaluation of the decellularized lungs demonstrated no residual cellular debris; morphometry demonstrated a mean 39 ± 7% reduction in lung dimensions. Scanning electron microscopy (SEM) demonstrated an intact structural hierarchy within the decellularized lung. Light, fluorescence, and SEM of precision-cut lung slices demonstrated that alveolar duct structure was defined by a cable line element encased in basement membrane. The cable line element arose in the distal airways, passed through septal tips and inserted into neighboring blood vessels and visceral pleura. The ropelike appearance, collagenase resistance and anti-elastin immunostaining indicated that the cable was an elastin macromolecule. Our results indicate that the helical line element of the axial connective tissue system is composed of an elastin cable that not only defines the structure of the alveolar duct, but also integrates the axial connective tissue system into visceral pleura and peripheral blood vessels.

In most mammals, removing one lung (pneumonectomy) results in the compensatory growth of the remaining lung. In mice, stereological observations have demonstrated an increase in the number of mature alveoli; however, anatomic evidence of the early phases of alveolar growth has remained elusive. To identify changes in the lung microstructure associated with neoalveolarization, we used tissue histology, electron microscopy, and synchrotron imaging to examine the configuration of the alveolar duct after murine pneumonectomy. Systematic histological examination of the cardiac lobe demonstrated no change in the relative frequency of dihedral angle components (Ends, Bends, and Junctions) ( P > 0.05), but a significant decrease in the length of a subset of septal ends (“E”). Septal retraction, observed in 20–30% of the alveolar ducts, was maximal on day 3 after pneumonectomy ( P < 0.01) and returned to baseline levels within 3 wk. Consistent with septal retraction, the postpneumonectomy alveolar duct diameter ratio (Dout:Din) was significantly lower 3 days after pneumonectomy compared to all controls except for the detergent-treated lung ( P < 0.001). To identify clumped capillaries predicted by septal retraction, vascular casting, analyzed by both scanning electron microscopy and synchrotron imaging, demonstrated matted capillaries that were most prominent 3 days after pneumonectomy. Numerical simulations suggested that septal retraction could reflect increased surface tension within the alveolar duct, resulting in a new equilibrium at a higher total energy and lower surface area. The spatial and temporal association of these microstructural changes with postpneumonectomy lung growth suggests that these changes represent an early phase of alveolar duct remodeling.

Objective The aim of the study was to evaluate the clinical and hemodynamic performance of the 3f Enable (Medtronic Inc, Minneapolis, Minn) sutureless bioprosthesis in the early postoperative period. Its implantation technique was also evaluated highlighting the modifications in regard to the original technique and mistakes made throughout the learning curve. Methods This is a prospective, nonrandomized study. From February 2011 to March 2014, a total of 60 patients underwent aortic valve replacement with the 3f Enable valve at the Hospiten Rambla. All intraoperative and postoperative data were prospectively collected. Results The mean age was 81.3 ± 3.78 years. Mean logistic European System for Cardiac Operative Risk Evaluation I was 13.78%. An associated concomitant procedure was performed in 23 patients (38.3%). The extracorporeal circulation and crossclamping times were 49.8 ± 15.7 minutes and 35.4 ± 8.9 minutes, respectively. The average stay in the intensive care unit was 34.7 hours. Mean systolic pressure gradients ranged from 8.01 mm Hg (size 19 valve) to 7.2 mm Hg (size 25 valve). Mean effective orifice area ranged from 1.9 cm 2 (size 19 valve) to 2.5 cm 2 (size 25 valve). Severe mismatch ( 2 /m 2 ) did not occur in any patient. Only 1.66% of patients had more than mild aortic insufficiency at discharge. The early (30-day) mortality was 6.6% (n = 4). Conclusions The 3f Enable bioprosthesis is an important alternative to conventional prostheses, with reduction of surgery times and good hemodynamic results on discharge. It is especially useful for high-risk patients and octogenarians. Studies on a greater number of patients and long-term follow-ups are necessary.

Pleural injury and associated air leaks are a major influence on patient morbidity and healthcare costs after lung surgery. Pectin, a plant-derived heteropolysaccharide, has recently demonstrated potential as an adhesive binding to the glycocalyx of visceral mesothelium. Since bioadhesion is a process likely involving the interpenetration of the pectin-based polymer with the glycocalyx, we predicted that the pectin-based polymer may also be an effective sealant for pleural injury. To explore the potential role of an equal (weight%) mixture of high-methoxyl pectin and carboxymethylcellulose as a pleural sealant, we compared the yield strength of the pectin-based polymer to commonly available surgical products. The pectin-based polymer demonstrated significantly greater adhesion to the lung pleura than the comparison products (p 0.05). In 7-day survival experiments, the application of the pectin-based polymer after pleural injury was associated with no observable toxicity, 100% survival (N = 5), and restored lung function. We conclude that this pectin-based polymer is a strong and nontoxic bioadhesive with the potential for clinical application in the treatment of pleural injuries.

The St. Jude Medical Trifecta aortic bioprosthesis (St. Jude Medical, Inc., St. Paul, MN, USA) is a new stented pericardial tissue heart valve. The aim of the study was to evaluate the clinical and haemodynamic performance of the Trifecta bioprosthesis in the early postoperative period.From July 2010 to September 2012, a total of 200 consecutive patients underwent aortic valve replacement with the Trifecta valve in our institution. All intraoperative and postoperative data were prospectively collected. Mean EuroSCORE II was 3.98%. Echocardiography was performed at discharge in all patients.The mean age was 71.2 ± 7.7 (range 39-89 years). Extubation in the operating theatre was successfully performed in 96% of patients. Mean hospital stay was 8.5 days. The prosthesis sizes were 19 mm (n = 33), 21 mm (n = 81), 23 mm (n = 59), 25 mm (n = 23) and 27 mm (n = 4). Mean systolic pressure gradients ranged from 9.4 mmHg (size 19 valve) to 4.8 mmHg (size 27 valve). Mean effective orifice area (EOA) ranged from 1.61 cm(2) (size 19 valve) to 2.5 cm(2) (size 27 valve). Severe mismatch (0.65 cm(2)/m(2)) did not occur in any patient. Of note, 99.5% of patients had mild or no aortic insufficiency at discharge. The early (30-day) mortality was 2.5% (n = 5).The Trifecta valve offers good clinical results and excellent haemodynamic performance. Special care must be taken to avoid oversizing, which can lead to difficulty in implantation and can produce gradient increases due to an excess of prosthetic leaflet tissue.

Many neuropeptides are members of peptide families, with multiple structurally similar peptide isoforms frequently found even within a single species. This raises the question of whether the individual peptides serve common or distinct functions. In the companion paper to this article (Dickinson, P.S., Sreekrishnan, A., Kwiatkowski, M.A. and Christie, A.E. 2015. Distinct or shared actions of peptide family isoforms: I. Peptide-specific actions of pyrokinins in the lobster cardiac neuromuscular system. J. Exp. Biol, submitted), we found high isoform specificity in the responses of the lobster (Homarus americanus) cardiac neuromuscular system to members of the pyrokinin peptide family: only one of five crustacean isoforms showed any bioactivity in the cardiac system. Because previous studies in other species had found little isoform specificity in pyrokinin actions, we examined the effects of the same five crustacean pyrokinins on the lobster stomatogastric nervous system (STNS). In contrast to our findings in the cardiac system, the effects of the five pyrokinin isoforms on the STNS were indistinguishable: they all activated or enhanced the gastric mill motor pattern, but did not alter the pyloric pattern. These results, in combination with those from the cardiac ganglion, suggest that members of a peptide family in the same species can be both isoform-specific and highly promiscuous in their modulatory capacity. The mechanisms that underlie these differences in specificity have not yet been elucidated; one possible explanation, which has yet to be tested, is the presence and differential distribution of multiple receptors for members of this peptide family.

Introduction: In most mammals, including humans, unilateral pneumonectomy (PNX) results in non-uniform growth of the remaining lung. To identify regions of active regeneration, we used laser microd...

In many mammals, including rodents and humans, removal of one lung results in the compensatory growth of the remaining lung; however, the mechanism of compensatory lung growth is unknown. Here, we investigated the changes in morphology and phenotype of pleural cells after pneumonectomy. Between days 1 and 3 after pneumonectomy, cells expressing α-smooth muscle actin (SMA), a cytoplasmic marker of myofibroblasts, were significantly increased in the pleura compared to surgical controls (p < .01). Scanning electron microscopy of the pleural surface 3 days post-pneumonectomy demonstrated regions of the pleura with morphologic features consistent with epithelial-mesenchymal transition (EMT); namely, cells with disrupted intercellular junctions and an acquired mesenchymal (rounded and fusiform) morphotype. To detect the migration of the transitional pleural cells into the lung, a biotin tracer was used to label the pleural mesothelial cells at the time of surgery. By post-operative day 3, image cytometry of post-pneumonectomy subpleural alveoli demonstrated a 40-fold increase in biotin+ cells relative to pneumonectomy-plus-plombage controls (p < .01). Suggesting a similar origin in space and time, the distribution of cells expressing biotin, SMA, or vimentin demonstrated a strong spatial autocorrelation in the subpleural lung (p < .001). We conclude that post-pneumonectomy compensatory lung growth involves EMT with the migration of transitional mesothelial cells into subpleural alveoli.

Complex tissues such as the lung are composed of structural hierarchies such as alveoli, alveolar ducts, and lobules. Some structural units, such as the alveolar duct, appear to participate in tissue repair as well as the development of bronchioalveolar carcinoma. Here, we demonstrate an approach to conduct laser microdissection of the lung alveolar duct for single-cell PCR analysis. Our approach involved three steps. The initial preparation used mechanical sectioning of the lung tissue with sufficient thickness to encompass the structure of interest. In the case of the alveolar duct, the precision-cut lung slices were 200µm thick; the slices were processed using near-physiologic conditions to preserve the state of viable cells. The lung slices were examined by transmission light microscopy to target the alveolar duct. The air-filled lung was sufficiently accessible by light microscopy that counterstains or fluorescent labels were unnecessary to identify the alveolar duct. The enzymatic and microfluidic isolation of single cells allowed for the harvest of as few as several thousand cells for PCR analysis. Microfluidics based arrays were used to measure the expression of selected marker genes in individual cells to characterize different cell populations. Preliminary work suggests the unique value of this approach to understand the intra- and intercellular interactions within the regenerating alveolar duct., National Institutes of Health (U.S.) (Grants HL94567 and CA009535)

In most rodents and some other mammals, the removal of one lung results in compensatory growth associated with dramatic angiogenesis and complete restoration of lung capacity. One pivotal mechanism in neoalveolarization is neovascularization, because without angiogenesis new alveoli can not be formed. The aim of this study is to image and analyze three-dimensionally the different patterns of neovascularization seen following pneumonectomy in mice on a sub-micron-scale. C57/BL6 mice underwent a left-sided pneumonectomy. Lungs were harvested at various timepoints after pneumonectomy. Volume analysis by microCT revealed a striking increase of 143 percent in the cardiac lobe 14 days after pneumonectomy. Analysis of microvascular corrosion casting demonstrated spatially heterogenous vascular densitities which were in line with the perivascular and subpleural compensatory growth pattern observed in anti-PCNA-stained lung sections. Within these regions an expansion of the vascular plexus with increased pillar formations and sprouting angiogenesis, originating both from pre-existing bronchial and pulmonary vessels was observed. Also, type II pneumocytes and alveolar macrophages were seen to participate actively in alveolar neo-angiogenesis after pneumonectomy. 3D-visualizations obtained by high-resolution synchrotron radiation X-ray tomographic microscopy showed the appearance of double-layered vessels and bud-like alveolar baskets as have already been described in normal lung development. Scanning electron microscopy data of microvascular architecture also revealed a replication of perialveolar vessel networks through septum formation as already seen in developmental alveolarization. In addition, the appearance of pillar formations and duplications on alveolar entrance ring vessels in mature alveoli are indicative of vascular remodeling. These findings indicate that sprouting and intussusceptive angiogenesis are pivotal mechanisms in adult lung alveolarization after pneumonectomy. Various forms of developmental neoalveolarization may also be considered to contribute in compensatory lung regeneration., Angiogenesis, 17 (3), ISSN:1573-7209, ISSN:0969-6970

In many mammalian species, the removal of one lung [pneumonectomy (PNX)] is associated with the compensatory growth of the remaining lung. To investigate the hypothesis that parenchymal deformation may trigger lung regeneration, we used respiratory-gated micro-computed tomography scanning to create three-dimensional finite-element geometric models of the murine cardiac lobe with cyclic breathing. Models were constructed of respiratory-gated micro-computed tomography scans pre-PNX and 24 h post-PNX. The computational models demonstrated that the maximum stretch ratio map was patchy and heterogeneous, particularly in subpleural, juxta-diaphragmatic, and cephalad regions of the lobe. In these parenchymal regions, the material line segments at peak inspiration were frequently two- to fourfold greater after PNX; some regions of the post-PNX cardiac lobe demonstrated parenchymal compression at peak inspiration. Similarly, analyses of parenchymal maximum shear strain demonstrated heterogeneous regions of mechanical stress with focal regions demonstrating a threefold increase in shear strain after PNX. Consistent with previously identified growth patterns, these subpleural regions of enhanced stretch and shear strain are compatible with a mechanical signal, likely involving cyclic parenchymal stretch, triggering lung growth.