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Cell and Tissue Research Mar 2017The study of the structural basis of gas exchange function in the lung depends on the availability of quantitative information that concerns the structures establishing... (Review)
Review
The study of the structural basis of gas exchange function in the lung depends on the availability of quantitative information that concerns the structures establishing contact between the air in the alveoli and the blood in the alveolar capillaries, which can be entered into physiological equations for predicting oxygen uptake. This information is provided by morphometric studies involving stereological methods and allows estimates of the pulmonary diffusing capacity of the human lung that agree, in experimental studies, with the maximal oxygen consumption. The basis for this "machine lung" structure lies in the complex design of the cells building an extensive air-blood barrier with minimal cell mass.
Topics: Animals; Diffusion; Gases; Humans; Lung
PubMed: 27981379
DOI: 10.1007/s00441-016-2541-4 -
Annals of the American Thoracic Society Nov 2019Pleuroparenchymal fibroelastosis (PPFE) is an unusual pulmonary disease with unique clinical, radiological, and pathological characteristics. Designated a rare... (Review)
Review
Pleuroparenchymal fibroelastosis (PPFE) is an unusual pulmonary disease with unique clinical, radiological, and pathological characteristics. Designated a rare idiopathic interstitial pneumonia in 2013, its name refers to a combination of fibrosis involving the visceral pleura and fibroelastotic changes predominating in the subpleural lung parenchyma. Although a number of disease associations have been described, no single cause of PPFE has been unequivocally identified. A diagnosis of PPFE is most commonly achieved by identifying characteristic abnormalities on computed tomographic scans. The earliest changes are consistently located in the upper lobes close to the lung apices, the same locations where subsequent disease progression is also most conspicuous. When sufficiently severe, the disease leads to progressive volume loss of the upper lobes, which, in combination with decreased body mass, produces platythorax. Once regarded as a slowly progressing entity, it is now acknowledged that some patients with PPFE follow an inexorably progressive course that culminates in irreversible respiratory failure and early death. In the absence of effective medical drug treatment, lung transplant remains the only therapeutic option for this disorder. This review focuses on improving early disease recognition and evaluating its pathophysiological impact and discusses working approaches for its management.
Topics: Bone Marrow Transplantation; Fibrosis; Humans; Immunosuppressive Agents; Lung; Lung Diseases, Interstitial; Lung Transplantation; Pleura; Pulmonary Fibrosis; Tomography, X-Ray Computed
PubMed: 31425665
DOI: 10.1513/AnnalsATS.201902-181CME -
Seminars in Fetal & Neonatal Medicine Aug 2017Pulmonary hypoplasia, although rare, is associated with significant neonatal morbidity and mortality. Conditions associated with pulmonary hypoplasia include those which... (Review)
Review
Pulmonary hypoplasia, although rare, is associated with significant neonatal morbidity and mortality. Conditions associated with pulmonary hypoplasia include those which limit normal thoracic capacity or movement, including skeletal dysplasias and abdominal wall defects; those with mass effect, including congenital diaphragmatic hernia and pleural effusions; and those with decreased amniotic fluid, including preterm, premature rupture of membranes, and genitourinary anomalies. The ability to predict severe pulmonary hypoplasia prenatally aids in family counseling, as well as obstetric and neonatal management. The objective of this review is to outline the imaging techniques that are widely used prenatally to assess pulmonary hypoplasia and to discuss the limitations of these methods.
Topics: Abnormalities, Multiple; Female; Fetal Development; Humans; Lung; Lung Diseases; Magnetic Resonance Imaging; Organ Size; Pregnancy; Severity of Illness Index; Ultrasonography, Doppler; Ultrasonography, Prenatal
PubMed: 28325581
DOI: 10.1016/j.siny.2017.03.001 -
Clinical Imaging May 2021Pulmonary sequestration consists of a nonfunctioning mass of lung tissue, either sharing the pleural envelope of the normal lung (intralobar) or with its own pleura... (Review)
Review
Pulmonary sequestration consists of a nonfunctioning mass of lung tissue, either sharing the pleural envelope of the normal lung (intralobar) or with its own pleura (extralobar), lacking normal communication with the tracheobronchial tree and receiving its arterial supply by one or more systemic vessels. It is the second most common congenital lung anomaly according to pediatric case series, but its real prevalence is likely to be underestimated, and imaging plays a key role in the diagnosis and treatment management of the condition and its potential complications. We will give a brief overview of the pathophysiology, clinical presentation and imaging findings of intra- and extralobar pulmonary sequestration, with particular reference to multidetector computed tomography as part of a powerful and streamlined diagnostic approach.
Topics: Bronchi; Bronchopulmonary Sequestration; Child; Humans; Lung; Pleura; Radiologists
PubMed: 33310586
DOI: 10.1016/j.clinimag.2020.11.040 -
Journal of the College of Physicians... Jun 2019Pneumocytoma is a rare benign tumor of the lung that usually manifests as a solitary pulmonary nodule. A 69-year lady, who had history of tuberculosis treatment 20 years...
Pneumocytoma is a rare benign tumor of the lung that usually manifests as a solitary pulmonary nodule. A 69-year lady, who had history of tuberculosis treatment 20 years ago, admitted to the hospital. A round mass was seen on chest radiography. Thorax computed tomography was reported as a round lesion in the left lung. Fiberoptic broncoscopy, computed tomography-guided fine-needle aspiration cytology and intraoperative frozen section analyses were undiagnostic. We performed wedge resection with minithoracotomy. Pathologic examination was reported as pneumocytoma. The patient did not receive any chemotherapy or radiotherapy after the operation. After 41 months' follow-up, no recurrent lesion was seen.
Topics: Aged; Biopsy, Fine-Needle; Female; Humans; Lung; Lung Neoplasms; Pulmonary Sclerosing Hemangioma; Thoracotomy; Tomography, X-Ray Computed; Treatment Outcome; Tuberculosis
PubMed: 31133161
DOI: 10.29271/jcpsp.2019.06.580 -
Current Opinion in Allergy and Clinical... Apr 2023Over the past 40 years, the circumstances where fungal bioaerosols are major issues have shifted because of changes in the industrial sector from mainly agriculture to... (Review)
Review
PURPOSE OF REVIEW
Over the past 40 years, the circumstances where fungal bioaerosols are major issues have shifted because of changes in the industrial sector from mainly agriculture to operations, including composting, cannabis production and forestry in hot humid conditions. Changes in the design and operation of nonindustrial workplaces meant that mould and dampness became major issues that are just being reduced. This review attempts to frame that history offers a perspective on the current thinking on mechanisms and provide potentially useful sources of information for physicians and their patients.
RECENT FINDINGS
The major impact of fungal exposures is not only from their allergens but also from an array of Danger-Associated Molecular Pattern molecules, possibly the most important of which is the type of glucan found in moulds that grow in damp buildings, wood chips and crops, that is beta 1, 3 D glucan in triple helical form. Located in lung epithelia, the dectin receptor is exquisitely sensitive to this compound. Except in some agricultural workplaces, low molecular weight secondary metabolites often mischaracterized as mycotoxins play little, if any, role on population health.
SUMMARY
There has been a convergence in thinking between the allergy and industrial hygiene communities as well as government agencies on mould and occupational health. This has led to some useful strategies for better managing these issues as well as increasing consumer awareness.
Topics: Humans; Fungi; Allergens; Lung; Glucans; Occupational Exposure
PubMed: 36752376
DOI: 10.1097/ACI.0000000000000886 -
Anesthesiology Nov 2020Prone ventilation redistributes lung inflation along the gravitational axis; however, localized, nongravitational effects of body position are less well characterized....
BACKGROUND
Prone ventilation redistributes lung inflation along the gravitational axis; however, localized, nongravitational effects of body position are less well characterized. The authors hypothesize that positional inflation improvements follow both gravitational and nongravitational distributions. This study is a nonoverlapping reanalysis of previously published large animal data.
METHODS
Five intubated, mechanically ventilated pigs were imaged before and after lung injury by tracheal injection of hydrochloric acid (2 ml/kg). Computed tomography scans were performed at 5 and 10 cm H2O positive end-expiratory pressure (PEEP) in both prone and supine positions. All paired prone-supine images were digitally aligned to each other. Each unit of lung tissue was assigned to three clusters (K-means) according to positional changes of its density and dimensions. The regional cluster distribution was analyzed. Units of tissue displaying lung recruitment were mapped.
RESULTS
We characterized three tissue clusters on computed tomography: deflation (increased tissue density and contraction), limited response (stable density and volume), and reinflation (decreased density and expansion). The respective clusters occupied (mean ± SD including all studied conditions) 29.3 ± 12.9%, 47.6 ± 11.4%, and 23.1 ± 8.3% of total lung mass, with similar distributions before and after lung injury. Reinflation was slightly greater at higher PEEP after injury. Larger proportions of the reinflation cluster were contained in the dorsal versus ventral (86.4 ± 8.5% vs. 13.6 ± 8.5%, P < 0.001) and in the caudal versus cranial (63.4 ± 11.2% vs. 36.6 ± 11.2%, P < 0.001) regions of the lung. After injury, prone positioning recruited 64.5 ± 36.7 g of tissue (11.4 ± 6.7% of total lung mass) at lower PEEP, and 49.9 ± 12.9 g (8.9 ± 2.8% of total mass) at higher PEEP; more than 59.0% of this recruitment was caudal.
CONCLUSIONS
During mechanical ventilation, lung reinflation and recruitment by the prone positioning were primarily localized in the dorso-caudal lung. The local effects of positioning in this lung region may determine its clinical efficacy.
Topics: Animals; Lung; Models, Animal; Prone Position; Pulmonary Ventilation; Respiration, Artificial; Supine Position; Swine; Tomography, X-Ray Computed
PubMed: 32773690
DOI: 10.1097/ALN.0000000000003509 -
American Journal of Physiology. Lung... Sep 2023Obesity is mostly associated with adverse health consequences, but may also elicit favorable effects under chronic conditions. This "obesity paradox" is under debate for...
Obesity is mostly associated with adverse health consequences, but may also elicit favorable effects under chronic conditions. This "obesity paradox" is under debate for pulmonary diseases. As confounding factors complicate conclusions from human studies, this study used a controlled animal model combining diet-induced obesity and chronic hypoxia as a model for pulmonary hypertension and chronic obstructive pulmonary disease. Male C57BL/6 mice were fed control or high-fat diet for 30 wk, and half of the animals were exposed to chronic hypoxia (13% O) for 3 wk. Hypoxia induced right ventricular hypertrophy, thickening of pulmonary arterial and capillary walls, higher lung volumes, and increased hemoglobin concentrations irrespective of the body weight. In contrast, lung proteomes differed substantially between lean- and obese-hypoxic mice. Many of the observed changes were linked to vascular and extracellular matrix (ECM) proteins. In lean-hypoxic animals, circulating platelets were reduced and abundances of various clotting-related proteins were altered, indicating a hypercoagulable phenotype. Moreover, the septal ECM composition was changed, and airspaces were significantly distended pointing to lung hyperinflation. These differences were mostly absent in the obese-hypoxic group. However, the obesity-hypoxia combination induced the lowest blood CO concentrations, indicating hyperventilation for sufficient oxygen supply. Moreover, endothelial surface areas were increased in obese-hypoxic mice. Thus, obesity exerts differential effects on lung adaptation to hypoxia, which paradoxically include not only adverse but also rather protective changes. These differences have a molecular basis in the lung proteome and may influence the pathogenesis of lung diseases. This should be taken into account for future individualized prevention and therapy. An "obesity paradox" is discussed for pulmonary diseases. By linking lung proteome analyses to pulmonary structure and function, we demonstrate that diet-induced obesity affects lung adaptation to chronic hypoxia in various ways. The observed changes include not only adverse but also protective effects and are associated with altered abundances of vascular and extracellular matrix proteins. These results highlight the existence of relevant differences in individuals with obesity that may influence the pathogenesis of lung diseases.
Topics: Humans; Mice; Animals; Male; Proteome; Mice, Inbred C57BL; Lung; Obesity; Hypertension, Pulmonary; Hypoxia
PubMed: 37461840
DOI: 10.1152/ajplung.00125.2023 -
Radiologic Clinics of North America May 2018Since MR imaging was introduced for the assessment of thoracic and lung diseases, various limitations have hindered its widespread adoption in clinical practice. Since... (Review)
Review
Since MR imaging was introduced for the assessment of thoracic and lung diseases, various limitations have hindered its widespread adoption in clinical practice. Since 2000, various techniques have been developed that have demonstrated the usefulness of MR imaging for lung cancer evaluation, and it is now reimbursed by health insurance companies in many countries. This article reviews recent advances in lung MR imaging, focusing on its use for lung cancer evaluation, especially with regard to pulmonary nodule detection, pulmonary nodule and mass assessment, lung cancer staging and detection of recurrence, postoperative lung function prediction, and therapeutic response evaluation and prediction.
Topics: Humans; Lung; Lung Neoplasms; Magnetic Resonance Imaging
PubMed: 29622078
DOI: 10.1016/j.rcl.2018.01.005 -
Clinical Infectious Diseases : An... Jul 2015Pulmonary tuberculosis is occasionally confused with invasive pulmonary aspergillosis (IPA) in transplant recipients, since clinical suspicion and early diagnosis of...
BACKGROUND
Pulmonary tuberculosis is occasionally confused with invasive pulmonary aspergillosis (IPA) in transplant recipients, since clinical suspicion and early diagnosis of pulmonary tuberculosis and IPA rely heavily on imaging modes such as computed tomography (CT). We therefore investigated IPA-mimicking tuberculosis in transplant recipients.
METHODS
All adult transplant recipients who developed tuberculosis or IPA at a tertiary hospital in an intermediate tuberculosis-burden country during a 6-year period were enrolled. First, we tested whether experienced radiologists could differentiate pulmonary tuberculosis from IPA. Second, we determined which radiologic findings could help us differentiate them.
RESULTS
During the study period, 28 transplant recipients developed pulmonary tuberculosis after transplantation, and 80 patients developed IPA after transplantation. Two experienced radiologists scored blindly 28 tuberculosis and 50 randomly selected IPA cases. The sensitivities of radiologists A and B for IPA were 78% and 68%, respectively (poor agreement, kappa value = 0.25). The sensitivities of radiologists A and B for tuberculosis were 64% and 61%, respectively (excellent agreement, kappa value = 0.77). We then compared the CT findings of the 28 patients with tuberculosis and 80 patients with IPA. Infarct-shaped consolidations and smooth bronchial wall thickening were more frequent in IPA, and mass-shaped consolidations and centrilobular nodules (<10 mm, clustered) were more frequent in tuberculosis.
CONCLUSIONS
Certain CT findings appear to be helpful in differentiating between IPA and tuberculosis. Nevertheless, the CT findings of about one-third of pulmonary tuberculosis cases in transplant recipients are very close to those of IPA.
Topics: Adult; Aged; Diagnosis, Differential; Female; Humans; Invasive Pulmonary Aspergillosis; Lung; Male; Middle Aged; Retrospective Studies; Tertiary Care Centers; Tomography, X-Ray Computed; Transplant Recipients; Tuberculosis, Pulmonary
PubMed: 25778752
DOI: 10.1093/cid/civ216