-
BioMed Research International 2018The aim of this study was to evaluate a novel composite material for tracheal reconstruction in an ovine model. A polymer containing various forms of carbon fibers...
The aim of this study was to evaluate a novel composite material for tracheal reconstruction in an ovine model. A polymer containing various forms of carbon fibers (roving, woven, and nonwoven fabric) impregnated with polysulfone (PSU) was used to create cylindrical tracheal implants, 3 cm in length and 2.5 cm in diameter. Each implant, reinforced with five rings made of PSU-impregnated carbon-fiber roving, had three external layers made of carbon-fiber woven fabric and the inner layer formed of carbon-fiber nonwoven fabric. The inner surface of five implants was additionally coated with polyurethane (PU), to promote migration of respiratory epithelium. The implants were used to repair tracheal defects (involving four tracheal rings) in 10 sheep (9-12 months of age; 40-50 kg body weight). Macroscopic and microscopic characteristics of the implants and tracheal anastomoses were examined 4 and 24 weeks after implantation. At the end of the follow-up period, outer surfaces of the implants were covered with the tissue which to various degree resembled histological structure of normal tracheal wall. In turn, inner surfaces of the prostheses were covered only with vascularized connective tissue. Inner polyurethane coating did not improve the outcomes of tracheal reconstruction and promoted excessive granulation, which contributed to moderate to severe stenosis at the tracheal anastomoses. The hereby presented preliminary findings constitute a valuable source of data for future research on a tracheal implant being optimally adjusted for medical needs.
Topics: Animals; Biocompatible Materials; Biomimetics; Polyurethanes; Prostheses and Implants; Plastic Surgery Procedures; Respiratory Mucosa; Sheep; Trachea
PubMed: 30417010
DOI: 10.1155/2018/2610637 -
Journal of Applied Physiology... Jan 2017Recent studies show that nasal high flow (NHF) therapy can support ventilation in patients with acute or chronic respiratory disorders. Clearance of dead space has been... (Randomized Controlled Trial)
Randomized Controlled Trial
UNLABELLED
Recent studies show that nasal high flow (NHF) therapy can support ventilation in patients with acute or chronic respiratory disorders. Clearance of dead space has been suggested as being the key mechanism of respiratory support with NHF therapy. The hypothesis of this study was that NHF in a dose-dependent manner can clear dead space of the upper airways from expired air and decrease rebreathing. The randomized crossover study involved 10 volunteers using scintigraphy with Krypton (Kr) gas during a breath-holding maneuver with closed mouth and in 3 nasally breathing tracheotomized patients by volumetric capnography and oximetry through sampling CO and O in the trachea and measuring the inspired volume with inductance plethysmography following NHF rates of 15, 30, and 45 l/min. The scintigraphy revealed a decrease in Kr gas clearance half-time with an increase of NHF in the nasal cavities [Pearson's correlation coefficient cc = -0.55, P < 0.01], the pharynx (cc = -0.41, P < 0.01), and the trachea (cc = -0.51, P < 0.01). Clearance rates in nasal cavities derived from time constants and MRI-measured volumes were 40.6 ± 12.3 (SD), 52.5 ± 17.7, and 72.9 ± 21.3 ml/s during NHF (15, 30, and 45 l/min, respectively). Measurement of inspired gases in the trachea showed an NHF-dependent decrease of inspired CO that correlated with an increase of inspired O (cc = -0.77, P < 0.05). NHF clears the upper airways of expired air, which reduces dead space by a decrease of rebreathing making ventilation more efficient. The dead space clearance is flow and time dependent, and it may extend below the soft palate.
NEW & NOTEWORTHY
Clearance of expired air in upper airways by nasal high flow (NHF) can be extended below the soft palate and de facto causes a reduction of dead space. Using scintigraphy, the authors found a relationship between NHF, time, and clearance. Direct measurement of CO and O in the trachea confirmed a reduction of rebreathing, providing the actual data on inspired gases, and this can be used for the assessment of other forms of respiratory support.
Topics: Carbon Dioxide; Cross-Over Studies; Female; Humans; Male; Middle Aged; Nasal Cavity; Nasal Mucosa; Nose; Oxygen; Pulmonary Ventilation; Respiration; Respiratory Dead Space; Tidal Volume; Trachea
PubMed: 27856714
DOI: 10.1152/japplphysiol.00584.2016 -
Environmental Health Perspectives Apr 1984Theoretical models of respiratory tract deposition of inhaled particles are compared to experimental studies of deposition patterns in humans and animals, as governed... (Review)
Review
Theoretical models of respiratory tract deposition of inhaled particles are compared to experimental studies of deposition patterns in humans and animals, as governed principally by particle size, density, respiratory rate and flow parameters. Various models of inhaled particle deposition make use of approximations of the respiratory tract to predict fractional deposition caused by fundamental physical processes of particle impaction, sedimentation, and diffusion. These models for both total deposition and regional (nasopharyngeal, tracheobronchial, and pulmonary) deposition are compared with early and recent experimental studies. Reasonable correlation has been obtained between theoretical and experimental studies, but the behavior in the respiratory tract of very fine (less than 0.1 micron) particles requires further investigation. Properties of particle shape, charge and hygroscopicity as well as the degree of respiratory tract pathology also influence deposition patterns; definitive experimental work is needed in these areas. The influence upon deposition patterns of dynamic alterations in inspiratory flow profiles caused by a variety of breathing patterns also requires further study, and the use of differing ventilation techniques with selected inhaled particle sizes holds promise in diagnosis of respiratory tract diseases. Mechanisms of conducting airway and alveolar clearance processes involving the pulmonary macrophage, mucociliary clearance, dissolution, transport to systemic circulation, and translocation via regional lymphatic vessels are discussed.
Topics: Animals; Bronchi; Humans; Lung; Lymph Nodes; Models, Biological; Mucous Membrane; Nose; Particle Size; Phagocytosis; Pharynx; Pulmonary Alveoli; Respiratory Physiological Phenomena; Respiratory System; Solubility; Trachea
PubMed: 6376108
DOI: 10.1289/ehp.8455369 -
ELife Sep 2022Basal cells are multipotent stem cells of a variety of organs, including the respiratory tract, where they are major components of the airway epithelium. However, it...
Basal cells are multipotent stem cells of a variety of organs, including the respiratory tract, where they are major components of the airway epithelium. However, it remains unclear how diverse basal cells are and how distinct subpopulations respond to airway challenges. Using single cell RNA-sequencing and functional approaches, we report a significant and previously underappreciated degree of heterogeneity in the basal cell pool, leading to identification of six subpopulations in the adult murine trachea. Among these, we found two major subpopulations, collectively comprising the most uncommitted of all the pools, but with distinct gene expression signatures. Notably, these occupy distinct ventral and dorsal tracheal niches and differ in their ability to self-renew and initiate a program of differentiation in response to environmental perturbations in primary cultures and in mouse injury models in vivo. We found that such heterogeneity is acquired prenatally, when the basal cell pool and local niches are still being established, and depends on the integrity of these niches, as supported by the altered basal cell phenotype of tracheal cartilage-deficient mouse mutants. Finally, we show that features that distinguish these progenitor subpopulations in murine airways are conserved in humans. Together, the data provide novel insights into the origin and impact of basal cell heterogeneity on the establishment of regionally distinct responses of the airway epithelium during injury-repair and in disease conditions.
Topics: Humans; Adult; Mice; Animals; Respiratory Mucosa; Epithelial Cells; Cell Differentiation; Trachea; RNA
PubMed: 36178196
DOI: 10.7554/eLife.80083 -
Anatomical Record (Hoboken, N.J. : 2007) Jun 2010The basement membrane zone (BMZ) appears as three component layers: the lamina lucida, lamina densa, and lamina reticularis. The laminas lucida and densa are present... (Review)
Review
The basement membrane zone (BMZ) appears as three component layers: the lamina lucida, lamina densa, and lamina reticularis. The laminas lucida and densa are present during all stages of development. The lamina reticularis appears during postnatal development. Collagens I, III, and V form heterogeneous fibers that account for the thickness of the lamina reticularis. Additionally, there are three proteoglycans considered as integral components of the BMZ: perlecan, collagen XVIII, and bamacan. Perlecan is the predominant heparan sulfate proteoglycan in the airway BMZ. It is responsible for many of the functions attributed to the BMZ, in particular, trafficking of growth factors and cytokines between epithelial and mesenchymal cells. Growth factor binding sites on perlecan include FGF-1, FGF-2, FGF-7, FGF-10, PDGF, HGF, HB-EGF, VEGF, and TGF-beta. Growth factors pass through the BMZ when moving between the epithelial and mesenchymal cell layers. They move by rapid reversible binding with sites on both the heparan sulfate chains and core protein of perlecan. In this manner, perlecan regulates movement of growth factors between tissues. Another function of the BMZ is storage and regulation of FGF-2. FGF-2 has been shown to be involved with normal growth and thickening of the BMZ. Thickening of the BMZ is a feature of airway remodeling in asthma. It may have a positive effect by protecting against airway narrowing and air trapping. Conversely, it may have a negative effect by influencing trafficking of growth factors in the epithelial mesenchymal trophic unit. However, currently the significance of BMZ thickening is not known.
Topics: Animals; Animals, Newborn; Basement Membrane; Humans; Lung Diseases; Primates; Respiratory Mucosa; Respiratory System; Trachea
PubMed: 20503389
DOI: 10.1002/ar.20824 -
Clinical and Experimental Immunology Feb 1971Rabbit antisera to human tracheal mucosa, liver and gastric mucosa, after complete absorption with human serum, reacted with extracts of all human tissues tested. Monkey...
Rabbit antisera to human tracheal mucosa, liver and gastric mucosa, after complete absorption with human serum, reacted with extracts of all human tissues tested. Monkey tissue extracts also reacted, but tissues of other species did not. The reactions were attributed to `species-specific tissue antigens'. Two of the most prominent antigens were partially isolated and characterized by chromatography, gel filtration, and electrophoresis. Antigen I migrated as β-globulin, Antigen E as a β-globulin. The antigens persisted in malignant and in long-term cultured cells.
Topics: Absorption; Animals; Antigens; Ascitic Fluid; Beta-Globulins; Cattle; Chromatography; Chromatography, DEAE-Cellulose; Chromatography, Gel; Cross Reactions; Culture Techniques; Epitopes; Gastric Mucosa; Haplorhini; Hemagglutination Inhibition Tests; Horses; Humans; Immunodiffusion; Immunoelectrophoresis; Liver; Neoplasms; Plasma; Rabbits; Sheep; Species Specificity; Swine; Trachea
PubMed: 4102258
DOI: No ID Found -
Cell Proliferation Feb 2010To explore the role of Oct3/4, Nanog and Sox2 in regeneration of rat tracheal epithelium.
OBJECTIVES
To explore the role of Oct3/4, Nanog and Sox2 in regeneration of rat tracheal epithelium.
MATERIALS AND METHODS
An ex vivo model of rat tracheal epithelial regeneration using 5-fluorouracil (5-FU) was developed, to induce injury. Expression levels of Oct3/4, Nanog and Sox2 were examined using Western blot analysis, RT-PCR or microscopically observed immunofluorescence, and cell morphological changes were observed using HE staining, during the recovery process.
RESULTS
Oct3/4, Nanog and Sox2 were not detectable in normal tracheal epithelium. After treatment with 5-FU, the normally proliferating tracheal epithelium desquamated and only a few cells in G0 phase of the cell cycle were left on the basement membrane and Oct3/4, Nanog and Sox2 could be observed at this time. Thereafter, the number of Oct3/4-, Nanog- and Sox2-positive cells increased gradually. When the cells differentiated into ciliate cells, mucous cells or basal cells, and restored pseudostratified mucociliary epithelium, the number of Oct3/4-, Nanog- and Sox2-positive cells decreased and gradually disappeared.
CONCLUSIONS
G0 phase cells with resistance to 5-FU damage expressed Oct3/4, Nanog and Sox2. This indicated that these cells were undifferentiated, but had the ability to terminally differentiate into downstream-type cells. They possessed stem cell properties. The results are consistent with Oct3/4, Nanog and Sox2-expressing cells being considered as tracheal stem cells.
Topics: Animals; Benzimidazoles; Cell Differentiation; Cells, Cultured; Epithelium; Female; Fluorouracil; Homeodomain Proteins; Male; Nanog Homeobox Protein; Octamer Transcription Factor-3; Rats; Rats, Wistar; Regeneration; Resting Phase, Cell Cycle; SOXB1 Transcription Factors; Trachea; Transcription Factors
PubMed: 19845688
DOI: 10.1111/j.1365-2184.2009.00653.x -
The New England Journal of Medicine Jan 2010
Topics: Humans; Immune Tolerance; Mouth Mucosa; Neovascularization, Physiologic; Tissue and Organ Harvesting; Trachea; Transplantation Chimera; Transplantation Immunology; Transplantation, Heterotopic; Transplantation, Homologous; Transplants
PubMed: 20071709
DOI: 10.1056/NEJMe0908366 -
The Journal of Physiology Apr 2004The tracheobronchial submucosal glands secrete liquid that is important for hydrating airway surfaces, supporting mucociliary transport, and serving as a fluid matrix... (Review)
Review
The tracheobronchial submucosal glands secrete liquid that is important for hydrating airway surfaces, supporting mucociliary transport, and serving as a fluid matrix for numerous secreted macromolecules including the gel-forming mucins. This review details the essential structural elements of airway glands and summarizes what is currently known regarding the ion transport processes responsible for producing the liquid component of gland secretion. Liquid secretion most likely arises from serous cells and is principally under neural control with muscarinic agonists, substance P, and vasoactive intestinal peptide (VIP) functioning as effective secretogogues. Liquid secretion is driven by the active transepithelial secretion of both Cl(-) and HCO(3)(-) and at least a portion of this process is mediated by the cystic fibrosis transmembrane conductance regulator (CFTR), which is highly expressed in glands. The potential role of submucosal glands in cystic fibrosis lung disease is discussed.
Topics: Animals; Bronchi; Cystic Fibrosis; Humans; Lipid Metabolism; Respiratory Mucosa; Trachea
PubMed: 14660706
DOI: 10.1113/jphysiol.2003.052779 -
Zoological Research Jan 2017Polymeric immunoglobulin receptors(pIgR) are key participants in the formation and secretion of secretory IgA(S-IgA), which is critical for the prevention of microbial...
Polymeric immunoglobulin receptors(pIgR) are key participants in the formation and secretion of secretory IgA(S-IgA), which is critical for the prevention of microbial infection and colonization in the respiratory system. Although increased respiratory colonization and infections are common in HIV/AIDS, little is known about the expression of pIgR in the airway mucosa of these patients. To address this, the expression levels of pIgR in the tracheal mucosa and lungs of SHIV/SIV-infected rhesus macaques were examined by real-time RTPCR and confocal microscopy. We found that the levels of both mRNA and pIgR immunoreactivity were lower in the tracheal mucosa of SHIV/SIV-infected rhesus macaques than that in non-infected rhesus macaques, and the difference in pIgR immunoreactivity was statistically significant. IL-17A, which enhances pIgR expression, was also changed in the same direction as that of pIgR. In contrast to changes in the tracheal mucosa, pIgR and IL-17A levels were higher in the lungs of infected rhesus macaques. These results indicated abnormal pIgR expression in SHIV/SIV, and by extension HIV infections, which might partially result from IL-17A alterations and might contribute to the increased microbial colonization and infection related to pulmonary complications in HIV/AIDS.
Topics: Animals; Gene Expression Regulation; Macaca mulatta; Receptors, Polymeric Immunoglobulin; Respiratory Mucosa; Simian Acquired Immunodeficiency Syndrome; Simian Immunodeficiency Virus; Trachea
PubMed: 28271669
DOI: 10.13918/j.issn.2095-8137.2017.007