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Gautam, Ajeevan, Rajib Chaulagain e Deepesh Dhungel. "Morphological Variations of the Lungs: A Cadaveric Study". Nepal Medical College Journal 23, n.º 4 (31 de dezembro de 2021): 315–18. http://dx.doi.org/10.3126/nmcj.v23i4.42221.
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The lungs are the organs of respiration which are situated on either side of the heart and other mediastinal contents in its pleural cavity. A fresh lung is spongy, can float in water and crepitates when handled. Lungs are important with respect to its blood circulation. The lungs are divided by fissures into lobes which facilitate movements of lobes in relation to one another. The hilum of each lung is its gateway. In the present study, we aim to assess the morphological variations of human cadaveric lungs at Chitwan Medical College (CMC). An observational study was conducted at dissection hall of anatomy department at Chitwan Medical College from September 2019 to October 2020 after taking ethical approval form Institutional Review Committee of CMC. All the intact 70 lungs present in the department were studied. Photographs of the intact lungs were taken from different surface. The lungs were porus, highly elastic and spongy in texture. On keeping lungs to water tank it got floated. We found 34(80.96%) of the studied specimen of right side had horizontal fissure present in it. The remaining 8 (19.04%) specimens did not have horizontal fissures, while 3 (5.88%) specimens had incomplete fissures. The oblique fissure was not present in 2 (2.38%) of the study specimens. The left side of the study specimen has a variance of 1(4.16%). When the hilum right lung was examined, 40 (95.23%) of the structure had the usual organization pattern. In the left lung, the usual pattern of organization was 21(75%). The differences are thought to be present in the lung’s fissure and hilum. The current study’s findings are therapeutically important. The findings could prove beneficial to cardiovascular and thoracic surgeons.
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Koch, Achim, Nikolaus Pizanis, Carolin Olbertz, Omar Abou-Issa, Christian Taube, Alexis Slama, Clemens Aigner, Heinz G. Jakob e Markus Kamler. "One-year experience with ex vivo lung perfusion: Preliminary results from a single center". International Journal of Artificial Organs 41, n.º 8 (5 de julho de 2018): 460–66. http://dx.doi.org/10.1177/0391398818783391.
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Objective: To enlarge the donor pool for lung transplantation, an increasing number of extended criteria donor lungs are used. However, in more than 50% of multi-organ donors the lungs are not used. Ex vivo lung perfusion offers a unique possibility to evaluate and eventually recondition the injured donor lungs. The aim of our study was to assess the enlargement of the donor pool and the outcome with extended criteria donor lungs after ex vivo lung perfusion. Patients and Methods: Data were prospectively collected in our lung transplant database. We compared the results of lung transplants after ex vivo lung perfusion with those after conventional cold static preservation. In total, 11 extended criteria donor lungs processed with ex vivo lung perfusion and 41 cold static preservation lungs transplanted consecutively between May 2016 and May 2017 were evaluated. Normothermic ex vivo lung perfusion was performed according to the Toronto protocol for 4 h. Cold static preservation lungs were stored in low-potassium dextran solution. Results: Ex vivo lung perfusion lungs before procurement had significantly lower PaO2/FiO2 (P/F) ratios and more X-ray abnormalities. There were no statistically significant differences for pre-donation ventilation time, smoking history, or sex. After reconditioning with ex vivo lung perfusion, 9 out of 11 processed lungs were considered suitable and successfully transplanted. The mean postoperative ventilation time and in-hospital stay were not significantly different in ex vivo lung perfusion and cold static preservation recipients. Conclusion: Ex vivo lung perfusion can safely be used in the evaluation of lungs initially considered not suitable for transplantation. The primary outcome was not negatively affected and normothermic ex vivo lung perfusion is a useful tool to increase the usage of potentially transplantable lungs.
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Yablonskiy, Dmitriy A., Alexander L. Sukstanskii, Jason C. Woods, David S. Gierada, James D. Quirk, James C. Hogg, Joel D. Cooper e Mark S. Conradi. "Quantification of lung microstructure with hyperpolarized 3He diffusion MRI". Journal of Applied Physiology 107, n.º 4 (outubro de 2009): 1258–65. http://dx.doi.org/10.1152/japplphysiol.00386.2009.
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The structure and integrity of pulmonary acinar airways and their changes in different diseases are of great importance and interest to a broad range of physiologists and clinicians. The introduction of hyperpolarized gases has opened a door to in vivo studies of lungs with MRI. In this study we demonstrate that MRI-based measurements of hyperpolarized 3He diffusivity in human lungs yield quantitative information on the value and spatial distribution of lung parenchyma surface-to-volume ratio, number of alveoli per unit lung volume, mean linear intercept, and acinar airway radii—parameters that have been used by lung physiologists for decades and are accepted as gold standards for quantifying emphysema. We validated our MRI-based method in six human lung specimens with different levels of emphysema against direct unbiased stereological measurements. We demonstrate for the first time MRI images of these lung microgeometric parameters in healthy lungs and lungs with different levels of emphysema (mild, moderate, and severe). Our data suggest that decreases in lung surface area per volume at the initial stages of emphysema are due to dramatic decreases in the depth of the alveolar sleeves covering the alveolar ducts and sacs, implying dramatic decreases in the lung's gas exchange capacity. Our novel methods are sufficiently sensitive to allow early detection and diagnosis of emphysema, providing an opportunity to improve patient treatment outcomes, and have the potential to provide safe and noninvasive in vivo biomarkers for monitoring drug efficacy in clinical trials.
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James, A., G. Pearce-Pinto e D. Hillman. "Effects of lung volume and surface forces on maximal airway smooth muscle shortening". Journal of Applied Physiology 77, n.º 4 (1 de outubro de 1994): 1755–62. http://dx.doi.org/10.1152/jappl.1994.77.4.1755.
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The effects of lung volume and surface forces on airway smooth muscle shortening were studied in isolated perfused rat lungs. The lungs were inflated via the trachea with gas or Krebs solution (n = 12 each) to volumes equivalent to gas inflation pressures of 5 (low), 15 (medium), and 25 (high) cmH2O (n = 4 each). At each volume, two of the four lungs were perfused with methacholine (10(-2) M) and then all were perfused with Formalin for fixation. The amount of smooth muscle shortening present in transverse sections of the airways was determined by comparing the observed outer perimeter of the smooth muscle layer with its calculated relaxed perimeter. In the control lungs, mean shortening was < or = 10% in all groups except the liquid-filled lungs at low lung volumes [33 +/- 12% (SD)]. In the methacholine-stimulated lungs, mean shortening was between 45 and 56% at medium and low lung volumes in gas- and liquid-filled lungs, respectively, and approximated the degree of shortening required to cause airway closure. At high lung volume, less shortening was observed in the methacholine-stimulated lungs, either liquid (34 +/- 17%) or gas filled (16 +/- 19%; P < 0.05 compared with liquid filled). The effects of lung volume in liquid-filled lungs and the differences in response between gas- and liquid-filled lungs demonstrate, respectively, that both lung tissue recoil and surface forces act to oppose shortening of maximally stimulated smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)
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Hass, M. A., e D. Massaro. "Differences in CuZn superoxide dismutase induction in lungs of neonatal and adult rats". American Journal of Physiology-Cell Physiology 253, n.º 1 (1 de julho de 1987): C66—C70. http://dx.doi.org/10.1152/ajpcell.1987.253.1.c66.
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The failure of adult rats to survive prolonged exposure to greater than 95% O2 is generally ascribed to the inability of their lungs to increase antioxidant enzyme synthesis in response to the oxidant challenge. We studied the synthesis rate of the antioxidant enzyme CuZn superoxide dismutase (CuZn SOD) in lungs of adult and neonatal rats exposed to conditions that alter the lung's oxidant-to-antioxidant balance. Lung CuZn SOD synthesis in the adult was significantly increased after 24 h of hyperoxia but fell to control levels after further exposure, whereas in neonatal lungs an increased rate of synthesis of CuZn SOD was found only after 72 h of hyperoxia. The adult lung responded to two in vitro oxidant stresses, [diethyldithiocarbamate exposure and heat (42 degrees C)] with increases in CuZn SOD synthesis twice the magnitude of those in the neonatal lung. These data indicate that the adult lung is at least as capable as the neonatal lung of increasing its synthesis of CuZn SOD in response to an oxidative stress. However, the inability of the adult lung to maintain an increased rate of CuZn SOD synthesis during in vivo hyperoxia may contribute to the poor tolerance of the adult lung to greater than 95% O2.
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Stettler, L. E., S. F. Platek, D. H. Groth, F. H. Y. Green e V. Vallyathan. "Particle Contents of Human Lungs". Proceedings, annual meeting, Electron Microscopy Society of America 43 (agosto de 1985): 116–19. http://dx.doi.org/10.1017/s0424820100117595.
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Scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) have been used by numerous investigators to study the particle content of human lungs. Most of this work has been performed on lung specimens from subjects with known or suspected lung diseases. The object of these analyses has been an attempt to relate the composition and concentration of the particles present in the lungs to the lung disease. A major factor missing from past microanalysis work has been data from typical “normal” lungs with which the analyses of diseased lungs could be compared. Currently in progress at NIOSH, is a study in which the particle contents of 96 urban lungs from the Cincinnati, Ohio area are being determined.Preliminary results for thirty-five of these lung samples will be presented and discussed in the report. When completed, the analysis data will serve as background or baseline data for typical urban lungs with which comparisons of the particle contents of diseased lungs can be made.
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Szpinda, Michał, Waldemar Siedlaczek, Anna Szpinda, Alina Woźniak, Celestyna Mila-Kierzenkowska e Mateusz Badura. "Quantitative Anatomy of the Growing Lungs in the Human Fetus". BioMed Research International 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/362781.
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Using anatomical, digital, and statistical methods we examined the three-dimensional growth of the lungs in 67 human fetuses aged 16–25 weeks. The lung dimensions revealed no sex differences. The transverse and sagittal diameters and the base circumference were greater in the right lungs while the lengths of anterior and posterior margins and the lung height were greater in the left lungs. The best-fit curves for all the lung parameters were natural logarithmic models. The transverse-to-sagittal diameter ratio remained stable and averaged0.56±0.08and0.52±0.08for the right and left lungs, respectively. For the right and left lungs, the transverse diameter-to-height ratio significantly increased from0.74±0.09to0.92±0.08and from0.56±0.07to0.79±0.09, respectively. The sagittal diameter-to-height ratio significantly increased from1.41±0.23to1.66±0.18in the right lung, and from1.27±0.17to1.48±0.22in the left lung. In the fetal lungs, their proportionate increase in transverse and sagittal diameters considerably accelerates with relation to the lung height. The lung dimensions in the fetus are relevant in the evaluation of the normative pulmonary growth and the diagnosis of pulmonary hypoplasia.
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Ahn, So Yoon, Dong Kyung Sung, Yun Sil Chang e Won Soon Park. "Intratracheal Transplantation of Mesenchymal Stem Cells Attenuates Hyperoxia-Induced Microbial Dysbiosis in the Lungs, Brain, and Gut in Newborn Rats". International Journal of Molecular Sciences 23, n.º 12 (13 de junho de 2022): 6601. http://dx.doi.org/10.3390/ijms23126601.
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We attempted to determine whether intratracheal (IT) transplantation of mesenchymal stem cells (MSCs) could simultaneously attenuate hyperoxia-induced lung injuries and microbial dysbiosis of the lungs, brain, and gut in newborn rats. Newborn rats were exposed to hyperoxia (90% oxygen) for 14 days. Human umbilical cord blood-derived MSCs (5 × 105) were transplanted via the IT route on postnatal day (P) five. At P14, the lungs were harvested for histological, biochemical, and microbiome analyses. Bacterial 16S ribosomal RNA genes from the lungs, brain, and large intestine were amplified, pyrosequenced, and analyzed. IT transplantation of MSCs simultaneously attenuated hyperoxia-induced lung inflammation and the ensuing injuries, as well as the dysbiosis of the lungs, brain, and gut. In correlation analyses, lung interleukin-6 (IL-6) levels were significantly positively correlated with the abundance of Proteobacteria in the lungs, brain, and gut, and it was significantly inversely correlated with the abundance of Firmicutes in the gut and lungs and that of Bacteroidetes in the lungs. In conclusion, microbial dysbiosis in the lungs, brain, and gut does not cause but is caused by hyperoxic lung inflammation and ensuing injuries, and IT transplantation of MSCs attenuates dysbiosis in the lungs, brain, and gut, primarily by their anti-oxidative and anti-inflammatory effects.
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Kanaujea, Savita, Arvind Kumar Pankaj, Kaweri Dande, Sehra Jabeen e Navneet Kumar. "Morphological and morphometric analysis of lung: A cadaveric study". Asian Journal of Medical Sciences 15, n.º 3 (1 de março de 2024): 88–93. http://dx.doi.org/10.3126/ajms.v15i3.59845.
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Background: The lung is a respiratory organ in which steady development begins during the embryonic period at 0–7 weeks’ gestation and continues into early childhood. Cardiothoracic surgeries and procedures such as lobectomy, segmental resection of bronchoscopy, require a thorough knowledge of the anatomy of the lung. Study of length, fissures and lobes of the lung can guide the surgeons for the above procedures and help them to prevent undue complications during surgery. Many variations are noted by researchers till date in both the lungs in regards to length, breadth, fissures, and lobes. In the current study, we have also observed variations in fissures of lung. Aims and Objectives: To study the normal length, breadth, and thickness of both sides of lungs, variations in the length, breadth, and thickness of both sides of the lungs. To study the normal fissures, lobes and their variations, of both right and left lungs, and also to study the number of bronchi, pulmonary artery, and pulmonary vein. Materials and Methods: 50 Right and 50 left lungs were obtained from embalmed cadavers, used for dissection in the Department of Anatomy, King George’s Medical University, Lucknow, UP, by using measuring tape and measuring scale. Photography was done by a DSLR camera. Results: The left lung shows maximum variations in the hilum. Out of 50 left lungs, 6 showed the absence of oblique fissures, 2 lungs had 2 arteries, 2 lungs had 2 Veins, and 1 had 2 bronchi. Out of 50 right lungs, 2 lungs showed 2 arteries, 2 lungs had 2 veins, and 2 had 3 bronchi. Conclusion: Knowledge of normal measurements of both sides of the lungs and their variations may help cardiothoracic surgeons avoid complications during surgery and it may help radiologists resolve uncertain radiographic findings.
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Nelson, PG, e AM Perks. "Effects of lung expansion on lung liquid production in vitro by lungs from fetal guinea-pigs. II. Evidence for generation of an inhibitory factor". Reproduction, Fertility and Development 8, n.º 3 (1996): 347. http://dx.doi.org/10.1071/rd9960347.
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Lungs from near-term fetal guinea-pigs were supported in vitro for 3 h; lung liquid production was measured by a dye-dilution method using Blue Dextran 2000 [fetuses 63 +/- 2 days of gestation, 97.6 +/- 19.8 (SD) g body weight]. Preparations were incubated in pairs taken from the same mother. Twenty lungs incubated in pairs without treatment (controls) showed no significant changes in fluid production throughout incubation (analysis of variance; regression analysis); rates in successive hours were: first lung, 1.36 +/- 0.39, 1.09 +/- 0.34 and 1.27 +/- 0.42 ml/kg body weight per h; second lung, 1.46 +/- 0.52, 1.09 +/- 0.41 and 1.18 +/- 0.43 ml/kg body weight per h. Twenty lungs were incubated similarly in pairs, but after one hour one lung from each pair was expanded with Krebs-Henseleit saline in volumes approximating those of the first breath (68 +/- 10% of lung volume). The expanded lungs began to reabsorb fluid immediately after expansion; the untreated lungs also stopped production or reached reabsorption by the final hour. Rates in successive hours were: expanded lungs; before expansion, 1.00 +/- 0.21, after expansion, -0.23 +/- 0.17 and 0.14 +/- 0.09 ml/kg body weight per h; unexpanded lungs, 1.27 +/- 0.49, 0.02 +/- 0.01 and -0.01 +/- 0.004 ml/kg body weight per h. The decrease in production was significant for each type of lung. The effects persisted in both expanded and unexpanded lungs in the presence of 1.78 x 10(-5) M phentolamine (n = 12; 70 +/- 2% expansion). The results suggest that expansion of the lungs at birth may release an unknown inhibitory factor, provisionally termed Expansion Factor (EF), within the lungs; this agent, probably not a catecholamine, can change lung fluid production into reabsorption and may partly account for the failure of beta-antagonists to prevent fluid reabsorption at delivery.
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Khubutiya, M. Sh, A. M. Gasanov, E. A. Tarabrin, T. V. Chernen’kaya, T. E. Kallagov e E. I. Pervakova. "A comparison of airway microbiota in donors and recipients of lung transplants". Russian Pulmonology 29, n.º 2 (1 de julho de 2019): 184–88. http://dx.doi.org/10.18093/0869-0189-2019-29-2-184-188.
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This study was aimed at investigation of relationships between bronchial washing culture in post-transplant recipient and bronchial flora of the lung donor. Methods. A comparative analysis of bronchial washing cultures from 30 post-transplant lung recipients was performed. All lung donors were stratified to ideal, suboptimal and marginal donors according to the lung transplant suitability. Results. As a result, development of post-transplant pulmonary complications was directly related to bacterial flora of the donor lung. The incidence of pneumonia in post-transplant patients was 3.3% after transplantation of ideal donor lungs, 20% after transplantation of suboptimal donors lungs and 100% after transplantation of marginal donor lungs. Conclusion. The rate of pneumonia in transplanted lungs was directly related to bronchial flora in the donor lungs. This should be taken into account when planning antibacterial therapy after lung transplantation.
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Waltz, W. F., J. A. Burbach, E. H. Schlenker e B. E. Goodman. "Sodium transport and fluid balance in lungs from normal and dystrophic hamsters". Journal of Applied Physiology 77, n.º 4 (1 de outubro de 1994): 1750–54. http://dx.doi.org/10.1152/jappl.1994.77.4.1750.
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Gravimetric and sodium transport characteristics of lungs from BIO 14.6 (dystrophic) hamsters were compared with those of lungs from golden Syrian (normal) hamsters at 30 and 150 days of age. Isolated perfused lungs were used to determine lung permeability and fluid balance differences between normal and dystrophic animals at both ages. Apparent permeability-surface area products for air space-to-vascular space sodium, sucrose, and fluorescein isothiocyanate-labeled dextran fluxes were compared in the four groups of hamsters. Morphometric analysis of fixed lungs of representative hamsters from each group was also performed. Dystrophic hamsters exhibited higher lung wet-to-dry weight ratios than normal hamsters at both ages. Lungs from dystrophic hamsters were less sensitive to inhibition of sodium transport by amiloride than lungs from age-matched normal hamsters. Dystrophic hamster lungs had higher absolute permeabilities of the passively transported solutes, lower permeability values for sodium, and only one-half of the amiloride-sensitive sodium transport of lungs from age-matched normal hamsters. Differences in lung fluid balance between dystrophic and normal hamsters may be related to differences in sodium clearance.
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Roshankhah, Roshan, John Blackwell, Hong Yuan, Stephanie A. Montgomery, Thomas M. Egan e Marie Muller. "Investigating response to treatment of pulmonary fibrosis in rats using ultrasound multiple scattering". Journal of the Acoustical Society of America 151, n.º 4 (abril de 2022): A76. http://dx.doi.org/10.1121/10.0010708.
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Lung alveoli constitute a complex distribution of strong ultrasound scatterers, leading to multiple scattering (USMS). Conventional ultrasound cannot be utilized to produce images that would accurately render lung structure. Pulmonary fibrosis affects lung microstructure by thickening alveolar walls, which changes wave diffusion and scattering patterns by modifying the distribution and size of scatterers. We present a method for the quantitative approach of structural changes in lung parenchyma based on diffusion of ultrasound waves, relying on measurement of the scattering mean free path (SMFP). We quantify severity of lung damage due to bleomycin-induced fibrosis in rats, and to monitor response to Nintedanib treatment by comparing the SMFP in 6 control (normal) lungs, 6 fibrotic lungs, and 6 fibrotic lungs from rats treated with Nintedanib. We observed significant differences in SMFP among control lungs (483 ± 50 μm), fibrotic lungs (1433 ± 612 μm), and lungs from Nintedanib-treated rats (835 ± 149 μm) (mean ± sd). Strong correlations were observed between SMFP and fibrosis severity score on inflated ex vivo CT lung images (p = 0.076, r = 0.43), as well as between SMFP and modified Ashcroft score of inflation-fixed lungs stained with H&E and Sirius red (p = 0.008, r = 0.61). This suggests SMFP may be useful to monitor response to treatment of pulmonary fibrosis.
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Kudoh, Ichidai, Mika Ohtake, Hideo Nishizawa, Kiyoyasu Kurahashi, Satoshi Hattori, Fukuichiro Okumura, Jean-Francois Pittet e Jeanine Wiener-Kronish. "The Effect of Pentoxifylline on Acid-induced Alveolar Epithelial Injury". Anesthesiology 82, n.º 2 (1 de fevereiro de 1995): 531–41. http://dx.doi.org/10.1097/00000542-199502000-00023.
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Background Acid instillation into one lung is known to cause an increase in the permeability of the endothelium to protein in both the instilled and the contralateral lungs. Activated neutrophils are believed to be involved in causing this increased permeability. Pentoxifylline, a drug used in clinical practice, has multiple effects on neutrophils, including inhibition of phagocytosis, degranulation, and superoxide generation. This study investigated whether pretreatment with pentoxifylline would protect the alveolar epithelium or lung endothelium from injury. Methods The effect of acid instillation into one lung of anesthetized rabbits using several quantitative parameters was investigated. The quantification of the bidirectional movement of the alveolar (125I-albumin) and the circulating protein tracers (131I-albumin) was used as a measurement of the permeabilities of the lung epithelium and the lung endothelium in the acid-instilled lung. Bronchoalveolar lavage and measurement of the entry of the circulating protein tracer were used to assess the permeabilities of these barriers in the noninstilled lung. Results The instillation of HCl (pH 1.25, 1.2 ml/kg) into the right lung resulted in an increase in the protein permeability of the right lung's alveolar epithelium and endothelium as well as an increase in the permeability to protein of the left lung's endothelium. Pentoxifylline pretreatment attenuated the increase in the endothelial permeability of both lungs by 50% and restored the PaO2/FIO2 to normal in the pretreated animals exposed to acid injury. Conclusions Acid aspiration causes a dramatic increase in the alveolar epithelial permeability of the acid-instilled lung, but the permeability of the alveolar epithelium of the contralateral lung remains normal. In contrast, unilateral acid instillation causes an increase in the permeability of the endothelium of both lungs. The increase in endothelial permeability can be attenuated by pretreatment with pentoxifylline administration, and this leads to restoration of normal gas exchange.
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Pronych, Scott, e Richard Wassersug. "Lung use and development in Xenopus laevis tadpoles". Canadian Journal of Zoology 72, n.º 4 (1 de abril de 1994): 738–43. http://dx.doi.org/10.1139/z94-099.
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Shortly after hatching, Xenopus laevis tadpoles fill their lungs with air. We examined the role played by early lung use in these organisms, since they are able to respire with both their lungs and their gills. We investigated the effect on X. laevis development when the larvae were prevented from inflating their lungs, and whether early lung use influenced the size of the lungs or the tadpole's ability to metamorphose. Tadpoles that were denied access to air had lungs one-half the size of those of controls. This difference in lung size was too large to be explained merely by a stretching of the lung due to inflation. The longer tadpoles were denied access to air, the longer they took to metamorphose, and their probability of completing metamorphosis diminished. One tadpole raised throughout its larval life without access to air successfully metamorphosed but had abnormal, solidified lungs and an enlarged heart. Collectively, these experiments demonstrate that early lung use in tadpoles is important in determining both ultimate lung size and the probability of successfully metamorphosing. Lung use during early larval development in X. laevis is not absolutely necessary for survival through metamorphosis, but its absence severely handicaps growth.
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Syed, Ahad, Sarah Kerdi e Adnan Qamar. "Bioengineering Progress in Lung Assist Devices". Bioengineering 8, n.º 7 (28 de junho de 2021): 89. http://dx.doi.org/10.3390/bioengineering8070089.
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Artificial lung technology is advancing at a startling rate raising hopes that it would better serve the needs of those requiring respiratory support. Whether to assist the healing of an injured lung, support patients to lung transplantation, or to entirely replace native lung function, safe and effective artificial lungs are sought. After 200 years of bioengineering progress, artificial lungs are closer than ever before to meet this demand which has risen exponentially due to the COVID-19 crisis. In this review, the critical advances in the historical development of artificial lungs are detailed. The current state of affairs regarding extracorporeal membrane oxygenation, intravascular lung assists, pump-less extracorporeal lung assists, total artificial lungs, and microfluidic oxygenators are outlined.
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Gaman, S. A., S. K. Ternovoy, N. V. Pogosova, T. N. Veselova e M. A. Belkind. "DELAYED CT SCAN OF THE LUNGS IN PATIENTS WITH COVID-19 PNEUMONIA". Russian Electronic Journal of Radiology 11, n.º 1 (2021): 8–14. http://dx.doi.org/10.21569/2222-7415-2021-11-1-8-14.
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Purpose. Assessment the state of the lungs using CT in the dynamic follow-up of patients who have suffered from viral COVID-19 pneumonia in the delayed period after 6-10 months, and to identify the relationship of residual lung changes with the clinical condition and results of external respiratory function (ERF). Materials and methods. We examined 78 patients who had suffered from bilateral polysegmental viral COVID-19 pneumonia in April-May 2020, using multi-spiral computed tomography (CT) of the lungs. All patients had a medical history, performed CT scans of the lungs in the acute and delayed (6-10 months after hospitalization) phases, and a study of FVD in the delayed phase. The analysis of a series of tomograms of the lungs in dynamics was carried out. We developed an severity score of the lung condition (LungSS), expressed in the total score, which was calculated based on the score of typical patterns characteristic of viral Covid19-pneumonia, as well as residual changes and areas of fibrosis. LungSS was calculated for each patient in the acute and delayed follow-up periods. Results. The present study shows the dynamics of lung changes in the delayed period 6-10 months after the viral Covid19-pneumonia. Residual lung changes were detected in 66 people (84,6%). Of these, 35,9% of patients have areas of fibrosis, but most of the residual changes are linear and small-nodular seals (76,9%). The frequency of detection of residual reticular changes and consolidation was low (15,3%, 1,3%, respectively). Attention is drawn to the relatively frequent detection of areas of "Ground-glass opacity "(10,8%). In patients with severe and critical course of viral Covid19-pneumonia (CT3 and CT4), LungSS in the delayed follow-up period did not significantly differ from that in patients with mild and moderate course (CT1 and CT2) of the disease (4,5 [0,22], 2,5 [0,16], accordingly, p=0,61). There was no significant correlation between the detected residual lung changes in the delayed period and ERF. Conclusion. In a significant part of patients (84,6%) who have suffered from COVID19 viral pneumonia, residual changes in the lung parenchyma persist, mainly in the form of linear seals and to a lesser extent fibrosis. These changes did not have a reliable relationship with the results of the FVD. LungSS proposed in this study reflects the dynamic picture of lung changes in the acute and delayed period, and can be a good indicator for monitoring patients who have suffered from COVID-19 viral pneumonia.
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White, C. W., J. H. Jackson, I. F. McMurtry e J. E. Repine. "Hypoxia increases glutathione redox cycle and protects rat lungs against oxidants". Journal of Applied Physiology 65, n.º 6 (1 de dezembro de 1988): 2607–16. http://dx.doi.org/10.1152/jappl.1988.65.6.2607.
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Preexposure to hypoxia increased survival and lung reduced glutathione-to-oxidized glutathione ratios (GSH/GSSG) and decreased pleural effusions in rats subsequently exposed to continuous hyperoxia. In addition, lungs from hypoxia-preexposed rats developed less acute edematous injury (decreased lung weight gains and lung lavage albumin concentrations) than lungs from normoxia-preexposed rats when isolated and perfused with hydrogen peroxide (H2O2) generated by xanthine oxidase (XO) or glucose oxidase (GO). In contrast, when perfused with elastase or exposed to a hydrostatic left atrial pressure challenge, lungs isolated from hypoxia-preexposed rats developed the same acute edematous injury as lungs from normoxia-preexposed rats. The mechanism by which hypoxia preexposure conferred protection against H2O2 appeared to depend on hexose monophosphate shunt (HMPS)-dependent increases in lung glutathione redox cycle activity. First, before perfusion with GO, lungs from hypoxia-preexposed rats had increased glutathione peroxidase and glucose 6-phosphate dehydrogenase (but not catalase or glutathione reductase) activities compared with lungs from normoxia-preexposed rats. Second, after perfusion with GO, lungs from hypoxia-preexposed rats had increased H2O2 reducing equivalents, as reflected by increased GSH/GSSG and NADPH/NADPH+, compared with lungs from normoxia-preexposed rats. Third, pretreatment of rats with an HMPS inhibitor, (6-aminonicotinamide) or a glutathione reductase inhibitor, [1,3-bis(2-chloroethyl)-1-nitrosourea] prevented hypoxia-conferred protection against H2O2-mediated acute edematous injury in isolated lungs. These findings suggest that increased detoxification of H2O2 by glutathione redox cycle and HMPS-dependent mechanisms contributes to tolerance to hyperoxia and resistance to H2O2 of lungs from hypoxia-preexposed rats.
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Abernathy, V. J., N. A. Pou, R. E. Parker e R. J. Roselli. "Evaluation of perilla ketone-induced unilateral lung injury using external gamma scanning". Journal of Applied Physiology 76, n.º 1 (1 de janeiro de 1994): 138–45. http://dx.doi.org/10.1152/jappl.1994.76.1.138.
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We used a modified external gamma scanning technique to quantitate right and left lung permeability changes to iodinated sheep albumin before and after perilla ketone (PK)-mediated unilateral lung injury in seven anesthetized sheep. Three portable gamma scintillation probes containing 2-in. NaI crystals detected radioactivities of 51Cr-labeled red blood cells and 125I-labeled albumin over the right and left lungs and blood, respectively. Radioactivities were monitored for 1 h before and 3 h after infusion of 25 mg/kg PK into a single lung. Calculation of normalized slope index (NSI) (Roselli and Riddle, J. Appl. Physiol. 67: 2343–2350, 1989) over the 30-min interval before PK and over the 60- to 90-min interval after PK for each lung revealed a four- to five-fold NSI increase in lungs receiving PK (0.00237 +/- 0.00065 to 0.0109 +/- 0.0016 min-1) and no increase in contralateral control lungs (0.00214 +/- 0.00065 to 0.00201 +/- 0.00032 min-1). Observed changes in NSI were consistent with postmortem evaluations of each lung. Lungs receiving PK had significantly higher wet-to-dry lung weight ratios and extravascular lung water volumes than contralateral control lungs. Measured bloodless wet-to-dry lung weight ratios were 5.68 +/- 0.39 and 3.27 +/- 0.27 (P < 0.05) for PK and control lungs, respectively.
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Farrelly, C., e P. Greenaway. "GAS EXCHANGE THROUGH THE LUNGS AND GILLS IN AIR-BREATHING CRABS". Journal of Experimental Biology 187, n.º 1 (1 de fevereiro de 1994): 113–30. http://dx.doi.org/10.1242/jeb.187.1.113.
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Lung and gill performance in gas exchange have been evaluated in eight species of air-breathing crabs with two different lung circulatory designs, those with portal systems and smooth lung linings, and those without portal systems and with invaginated and evaginated lung linings. In all species, the lungs were extremely effective in oxygen uptake whilst the performance of the gills was inferior. An exception to this was Gecarcoidea natalis, which has gills highly modified for aerial gas exchange; its gills and lungs were equally efficient in O2 uptake. The relative efficiencies of the lungs and gills in CO2 excretion differed between species, with the gills being the major site of CO2 loss in the more amphibious species and the lungs having an increasingly important role in the more terrestrial crabs. The presence or absence of lung portal systems was not found to correlate with either saturation rates or efferent oxygen concentrations, with both lung types being extremely efficient in O2 uptake. The lungs with portal systems showed a large increase in oxygen content in the first lacunar bed and progressively smaller increases in the next two; these lungs may, therefore, have some reserve for exercise.
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Levvey, Bronwyn, Kovi Levin, Miranda Paraskeva, Glen Westall e Gregory Snell. "Donation after Brain Death versus Donation after Circulatory Death: Lung Donor Management Issues". Seminars in Respiratory and Critical Care Medicine 39, n.º 02 (26 de março de 2018): 138–47. http://dx.doi.org/10.1055/s-0037-1615820.
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AbstractLung transplantation (LTx) has traditionally been limited by a lack of suitable donor lungs. With the recognition that lungs are more robust than initially thought, the size of the donor pool of available lungs has increased dramatically in the past decade. Donation after brain death (DBD) and donation after circulatory death (DCD) lungs, both ideal and extended are now routinely utilized. DBD lungs can be damaged. There are important differences in the public's understanding, legal and consent processes, intensive care unit strategies, lung pathophysiology, logistics, and potential-to-actual donor conversion rates between DBD and DCD. Notwithstanding, the short- and long-term outcomes of LTx from any of these DBD versus DCD donor scenarios are now similar, robust, and continue to improve. Large audits suggest there remains a large untapped pool of DCD (but not DBD) lungs that may yet further dramatically increase lung transplant numbers. Donor scoring systems that might predict the donor conversion rates and lung quality, the role of ex vivo lung perfusion as an assessment and lung resuscitation tool, as well as the potential of donor lung quality biomarkers all have immense promise for the clinical field.
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Horalskyi, L., N. Hlukhova e I. Sokulskyi. "Morphological traits of rabbit lung". Scientific Horizons 93, n.º 8 (2020): 180–88. http://dx.doi.org/10.33249/2663-2144-2020-93-8-180-188.
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In the article, following the results of complex methods (anatomic, histologic, organometric, histometric and statistical) researches are shown the features of morphological structure and morphometric parameters of the lungs of mature rabbits. It was found out, that macro- and microscopic architecture of rabbit lungs has similar histoarchitectonics, inherent in other species of farm animals of the class "mammals" and the characteristic features of morphological structures. Lungs in clinically healthy rabbits structurally reflect the shape of thoracic cavity and gradually expand ventrally. Subsequent to the results of performed organometry, the absolute lung mass of mature rabbits is 18,05±1,32 g, relative 0,624±0,013 %. The Right and left rabbit lungs are surrounded by pleural sacs (right and left): in rabbits pleural spaces of the right and left lungs are not connected. According to morphological and organometric investigations the rabbit lungs are relating to VIII type – the reduction of the superior lobe of left lung is observed, consequently right lung is more developed than left ( the length of right lung is 6,40±0,45 mm, the width – 3,54±0,30 mm, the thickness – 3,28±0,30 mm; the length of left lung is 6,84±0,40 mm; 4,18±0,30 mm and 1,52±0,30 mm relatively) and the coefficient of lung asymmetry (right to left) according to their absolute mass is 1.16. Although, rabbit lungs have dilatated base and superior. Right lung divides into four lobes – cranial (the superior), cardio, diaphragmatic and ancilla, left one divides into three lobes – the reduced superior, cardio and diaphragmatic. Histoarchitecture of lungs is formed by lobes of the lungs, that are separated by connective tissue, which contains blood and lymphatic vessels. Lung parenchyma is created by airways and respiratory divisions that blood vessels accompany to. Respiratory lung parenchyma is formed by respiratory bronchioles, alveolar ducts and alveolar saccules, in which walls the alveolus are located and shape the alveolar tree. According to the analysis of histometry results, respiratory (breathing) lobe of lungs of experimental rabbits is 52,3± 0,62 %, connective tissue base – 69,6±1,27 %, and the average volume of alveolus (small, middle and big) is equal to 42,3±4,35 thousand mkm3.
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Devi, Sanjana, e Monika Gupta. "Absence of Horizontal Fissure, Middle Lobe Fusion and Anomalous Appearance of Mediastinal Surface of Right Lungs: A Rare Case Report". Scholars Journal of Medical Case Reports 11, n.º 08 (10 de agosto de 2023): 1478–80. http://dx.doi.org/10.36347/sjmcr.2023.v11i08.015.
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Anatomical variations of lungs in the form of presence of any extra lobe or absence of anatomical lobe, fissures of lungs are important to know to avoid injuries during surgeries related to lungs and associated structures. In this case report absence of middle lobe and horizontal fissure in two right lungs extracted from male cadaver during routine dissection in the Anatomy department, Adesh institute of medical sciences and research, Bathinda, Punjab, India was noted and reported. Every anatomical structure in left side lung of same cadaver was found normal. Also in one abnormal right lung, gross appearance of right lung was looked like left lung. Anatomical knowledge and statistics of every type of variations are important for anatomists for teaching purposes and for surgeons while performing lobectomies, surgical resections of segments of lungs and for radiological interpretations.
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Jafri, Farhana, Aliya Zahid e Javeria Ali. "A study of morphological variations of fissures and lobes of formalin fixed cadaveric lungs". Journal of Fatima Jinnah Medical University 16, n.º 3 (14 de março de 2023): 130–33. http://dx.doi.org/10.37018/zlvt6051.
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Background: Variation of morphology of lung fissures and lobes affects the interpretation of results of radiological examination as well as line of action in cardiothoracic surgical procedures. A research was done to find out the incidence of variations of fissures and lobes in embalmed cadaveric lungs.
Materials and methods: This is a cross sectional study. All the formalin fixed lung specimens present in dissection halls and museums of the Anatomy Departments were observed for any abnormal fissures that are adding accessory lobes to lungs. Data was entered and analyzed by using SPSS 22.0. Descriptive analysis was applied by using frequencies and percentages for qualitative variables.
Results: Total 80 formalin-fixed specimens of lungs were examined and a total of 29 (36.25%) (%) were found to have incomplete fissures. It was observed that 14 (17.5 %) out of 80 lungs had incomplete oblique fissures, and out of these 6 (17.65%) were found in right lungs and 08 (19.05%) were present in left lungs, whereas 15 (39.47%) right lungs showed incomplete horizontal fissure. Among 80 lungs, 6 (7.5%) presented unusual accessory fissures and lobes, whereas 5 (14.7%) showed absent horizontal fissure reducing the number of lobes to two in right lung specimen.
Conclusion: There is a prevalent incidence of incomplete horizontal fissure that must be kept in mind when investigating and treating any lung pathology.
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He, L. S., S. W. Chang, P. Ortiz de Montellano, T. J. Burke e N. F. Voelkel. "Lung injury in Fischer but not Sprague-Dawley rats after short-term hyperoxia". American Journal of Physiology-Lung Cellular and Molecular Physiology 259, n.º 6 (1 de dezembro de 1990): L451—L458. http://dx.doi.org/10.1152/ajplung.1990.259.6.l451.
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The Fischer rat is known for its susceptibility to develop liver necrosis when challenged with paraquat (Smith et al., J. Pharmacol. Exp. Ther. 235: 172-177, 1985). We postulated that other organs, specifically the lung, may also be more susceptible to injury and examined whether lungs from Fischer (F) rats were injured more easily when challenged with active oxygen species than Sprague-Dawley (SD) rat lungs. We aimed to investigate whether increased susceptibility to oxidant injury was related to differences in lung antioxidant defenses. Perfused lungs from both rat strains were challenged by addition of H2O2 to the perfusate or by short-term hyperoxic ventilation. To assess nonoxidant modes of lung injury, we examined lung responses after exposure to protamine sulfate or neutrophil elastase. Intravascular H2O2 or 3 h in vitro hyperoxia caused lung edema in F but not SD rats, and elastase injured F rat lungs more than the lungs from SD rats. Protamine, however, injured the lungs from both strains to a similar degree. Catalase, but not superoxide dismutase or allopurinol, protected F rat lungs against edema, resulting from 3 h in vitro hyperoxia. The lung homogenate levels for reduced glutathione or conjugated dienes and the activities of lung tissue catalase, glutathione peroxidase, and cytochrome P-450 were not different between the two strains. Lung tissue ATP levels, however, were lower in F than in SD rats. Although the F rat strain appears to have an altered oxidant-antioxidant defense balance, the exact cause of the greater susceptibility to oxidant stress of the F rat strain remains elusive.
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van Zanden, Judith E., Henri G. D. Leuvenink, Erik A. M. Verschuuren, Michiel E. Erasmus e Maximilia C. Hottenrott. "A translational rat model for ex vivo lung perfusion of pre-injured lungs after brain death". PLOS ONE 16, n.º 12 (2 de dezembro de 2021): e0260705. http://dx.doi.org/10.1371/journal.pone.0260705.
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The process of brain death (BD) detrimentally affects donor lung quality. Ex vivo lung perfusion (EVLP) is a technique originally designed to evaluate marginal donor lungs. Nowadays, its potential as a treatment platform to repair damaged donor lungs is increasingly studied in experimental models. Rat models for EVLP have been described in literature before, yet the pathophysiology of BD was not included in these protocols and prolonged perfusion over 3 hours without anti-inflammatory additives was not achieved. We aimed to establish a model for prolonged EVLP of rat lungs from brain-dead donors, to provide a reliable platform for future experimental studies. Rat lungs were randomly assigned to one of four experimental groups (n = 7/group): 1) healthy, directly procured lungs, 2) lungs procured from rats subjected to 3 hours of BD and 1 hour cold storage (CS), 3) healthy, directly procured lungs subjected to 6 hours EVLP and 4), lungs procured from rats subjected to 3 hours of BD, 1 hour CS and 6 hours EVLP. Lungs from brain-dead rats showed deteriorated ventilation parameters and augmented lung damage when compared to healthy controls, in accordance with the pathophysiology of BD. Subsequent ex vivo perfusion for 6 hours was achieved, both for lungs of healthy donor rats as for pre-injured donor lungs from brain-dead rats. The worsened quality of lungs from brain-dead donors was evident during EVLP as well, as corroborated by deteriorated ventilation performance, increased lactate production and augmented inflammatory status during EVLP. In conclusion, we established a stable model for prolonged EVLP of pre-injured lungs from brain-dead donor rats. In this report we describe tips and pitfalls in the establishment of the rat EVLP model, to enhance reproducibility by other researchers.
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Chen, Qihang, Jeffrey S. Klein, Gordon Gamsu e W. Richard Webb. "High-resolution computed tomography of the mammalian lung". American Journal of Veterinary Research 53, n.º 7 (1 de julho de 1992): 1218–24. http://dx.doi.org/10.2460/ajvr.1992.53.7.1218.
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Summary High-resolution computed tomography (HRCT) was performed in 21 isolated animal lungs, from 4 mammalian species (pigs, rabbits, dogs, sheep). Gross and subgross central and peripheral lung morphology was determined by HRCT. Three distinct types of lungs can be identified, principally based on the extent of interlobular septal development; the relationship of major vessels to airways; and the thickness of the visceral pleura. Type-I lung is found in pigs, sheep, and cattle; type-II lung is found in rabbits, dogs, cats, and monkeys; and type-IH lung is found in human beings and horses.1 These mammalian lungs were compared with human lungs. The potential use of HRCT to investigate specific human lung diseases in the aforementioned species also was considered.
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Mukhia, Rajeev, Dil Islam Mansur, Sidharth Timsina e Taneja BK. "Morphological and morphometrical studies of the human foetal lung". Asian Journal of Medical Sciences 10, n.º 5 (11 de agosto de 2019): 75–79. http://dx.doi.org/10.3126/ajms.v10i5.22136.
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Background: Foetal lung is one of the organs of interest for researchers since a long time. Though, detailed study about adult lung is there in the literature but lungs at different stages in foetal period is less available.
Aims and Objective: To find out the morphological and morphometrical features of the foetal lung in different gestational weeks.
Materials and Methods: After ethical approval the study was carried out on 66 human foetal lungs aged between 16th to 40th gestational weeks in the Department of Anatomy, Manipal College of Medical Sciences. After the dissection of foetuses, the lungs were removed out and the presence of fissures and lobes for both lungs were noted. Weights of both lungs were calibrated by digital weighing machine. Dimensions of foetal lungs were recorded by vernier calliper. All the data were represented as mean then analyzed with MS excel 2007 software and represented graphically.
Results: In the normally developing foetuses the dimensions of both lung increases with increase in gestational age with more or less difference between the dimension of right and left lung. There was number of variations seen in the fissures and lobes of the lungs.
Conclusion: The fissures and lobes are needed for locating broncho-pulmonary segments hence, knowledge of their position is necessary both anatomically as well as clinically for planning lobectomies and surgical resections.
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Czartolomna, J., N. F. Voelkel e S. W. Chang. "Permeability characteristics of isolated perfused rat lungs". Journal of Applied Physiology 70, n.º 4 (1 de abril de 1991): 1854–60. http://dx.doi.org/10.1152/jappl.1991.70.4.1854.
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We examined the factors that influence the permeability characteristics of isolated perfused rat lungs and compared the ex vivo permeability-surface area product (PS) with that obtained in vivo. In lungs perfused for 20 min with homologous blood or a physiological salt solution (PSS) containing 4 g/100 ml albumin, mean PS values, obtained by the single-sample method of Kern et al. [Am. J. Physiol. 245 (Heart Circ. Physiol. 14): H229-H236, 1983], were 9.9 +/- 0.6 (SE) and 6.8 +/- 0.3 cm3.min-1.g wet lung-1.10(-2), respectively. These values were similar to lung PS obtained in intact rats (7.7 +/- 0.4 cm3.min-1.g wet lung-1.10(-2). In perfused lungs, PS values were influenced by the perfusate albumin concentration, the length of perfusion time, and the degree of vascular recruitment. Twenty minutes after lung isolation, PS was 126% higher in lungs perfused with albumin-free PSS containing Ficoll than in lungs perfused with albumin-PSS. Moreover, PS in Ficoll-PSS-perfused lungs increased even higher after 2 h of perfusion, and this time-dependent increase in PS was attenuated by addition of 0.1 g/100 ml albumin to the perfusate. Two hours of ex vivo ventilation with hypoxic (0 or 3% 0(2)) or hyperoxic (95% 0(2)) gas mixture did not affect PS values in perfused lungs. However, PS was elevated in lungs perfused ex vivo with protamine, which causes endothelial cell injury, or in lungs from rats exposed in vivo to human recombinant tumor necrosis factor.(ABSTRACT TRUNCATED AT 250 WORDS)
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Huang, Yuh-Chin T., Andrew J. Ghio, Eva Nozik-Grayck e Claude A. Piantadosi. "Vascular release of nonheme iron in perfused rabbit lungs". American Journal of Physiology-Lung Cellular and Molecular Physiology 280, n.º 3 (1 de março de 2001): L474—L481. http://dx.doi.org/10.1152/ajplung.2001.280.3.l474.
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In this study, we hypothesized that the lung actively releases excess iron into the circulation to regulate iron homeostasis. We measured nonheme iron (NHFe) in the perfusate of control isolated perfused rabbit lungs and lungs with ischemia-reperfusion (I/R) ventilated with normoxic (21% O2) or hypoxic (95% N2) gas mixtures. Some were perfused with bicarbonate-free (HEPES) buffer or treated with the anion exchange inhibitor DIDS. The control lungs released ∼0.25 μg/ml of NHFe or 20% of the total lung NHFe into the vascular space that was not complexed with ferritin, transferrin, or lactoferrin or bleomycin reactive. The I/R lungs released a similar amount of NHFe during ischemia and some bleomycin-detectable iron during reperfusion. NHFe release was attenuated by ∼50% in both control and ischemic lungs by hypoxia and by >90% in control lungs and ∼60% in ischemic lungs by DIDS and HEPES. Reperfusion injury was not affected by DIDS or HEPES but was attenuated by hypoxia. These results indicate that biologically nonreactive nonheme iron is released rapidly by the lung into the vascular space via mechanisms that are linked to bicarbonate exchange. During prolonged ischemia, redox-active iron is also released into the vascular compartment by other mechanisms and may contribute to lung injury.
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Guo, Y. L., T. P. Kennedy, J. R. Michael, A. M. Sciuto, A. J. Ghio, N. F. Adkinson e G. H. Gurtner. "Mechanism of phosgene-induced lung toxicity: role of arachidonate mediators". Journal of Applied Physiology 69, n.º 5 (1 de novembro de 1990): 1615–22. http://dx.doi.org/10.1152/jappl.1990.69.5.1615.
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We have previously shown that phosgene markedly increases lung weight gain and pulmonary vascular permeability in rabbits. The current experiments were designed to determine whether cyclooxygenase- and lipoxygenase-derived mediators contribute to the phosgene induced lung injury. We exposed rabbits to phosgene (1,500 ppm/min), killed the animals 30 min later, and then perfused the lungs with a saline buffer for 90 min. Phosgene markedly increased lung weight gain, did not appear to increase the synthesis of cyclooxygenase metabolites, but increased 10-fold the synthesis of lipoxygenase products. Pre- or posttreatment with indomethacin decreased thromboxane and prostacyclin levels without affecting leukotriene synthesis and partially reduced the lung weight gain caused by phosgene. Methylprednisolone pretreatment completely blocked the increase in leukotriene synthesis and lung weight gain. Posttreatment with 5,8,11,14-eicosatetraynoic acid (ETYA), a nonmetabolized competitive inhibitor of arachidonic acid metabolism, or the leukotriene receptor blockers, FPL 55712 and LY 171883, also dramatically reduced the lung weight gain caused by phosgene. These results suggest that lipoxygenase products contribute to the phosgene-induced lung damage. Because phosgene exposure did not increase cyclooxygenase synthesis or pulmonary arterial pressure, we tested whether phosgene affects the lung's ability to generate or to react to thromboxane. Infusing arachidonic acid increased thromboxane synthesis to the same extent in phosgene-exposed lungs as in control lungs; however, phosgene exposure significantly reduced pulmonary vascular reactivity to thromboxane but not to angiotension II and KCl.
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Chen, C. R., N. F. Voelkel e S. W. Chang. "PAF potentiates protamine-induced lung edema: role of pulmonary venoconstriction". Journal of Applied Physiology 68, n.º 3 (1 de março de 1990): 1059–68. http://dx.doi.org/10.1152/jappl.1990.68.3.1059.
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We studied the synergistic interaction between platelet-activating factor (PAF) and protamine sulfate, a cationic protein that causes pulmonary endothelial injury, in isolated rat lungs perfused with a physiological salt solution. A low dose of protamine (50 micrograms/ml) increased pulmonary artery perfusion pressure (Ppa) but did not increase wet lung-to-body weight ratio after 20 min. Pretreatment of the lungs with a noninjurious dose of PAF (1.6 nM) 10 min before protamine markedly potentiated protamine-induced pulmonary vasoconstriction and resulted in severe lung edema and increased lung tissue content of 6-keto-prostaglandin F1 alpha, thromboxane B2, and leukotriene C4. Pulmonary microvascular pressure (Pmv), measured by double occlusion, was markedly increased in lungs given PAF and protamine. These potentiating effects of PAF were blocked by WEB 2086 (10(-5) M), a specific PAF receptor antagonist. Pretreatment of the lungs with a high dose of histamine (10(-4) M) failed to enhance the effect of protamine on Ppa, Pmv, or wet lung-to-body weight ratio. Furthermore, PAF pretreatment enhanced elastase-, but not H2O2-, induced lung edema. To assess the role of hydrostatic pressure in edema formation, we compared lung permeability-surface area products (PS) in papaverine-treated lungs given either protamine alone or PAF + protamine and tested the effect of mechanical elevation of Pmv on protamine-induced lung edema. In the absence of vasoconstriction, PAF did not potentiate protamine-induced increase in lung PS. On the other hand, mechanically raising Pmv in protamine-treated lungs to a level similar to that measured in lungs given PAF + protamine did not result in a comparable degree of lung edema. We conclude that PAF potentiates protamine-induced lung edema predominantly by enhanced pulmonary venoconstriction. However, a pressure-independent effect of PAF on lung vasculature cannot be entirely excluded.
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Rao, Kodavanti S. Prasada, e Harihara M. Mehendale. "Precursor utilization of 5-hydroxytryptophan for 5-hydroxytryptamine biosynthesis in isolated and perfused rabbit and rat lungs". Canadian Journal of Physiology and Pharmacology 65, n.º 10 (1 de outubro de 1987): 2117–23. http://dx.doi.org/10.1139/y87-332.
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The present study was designed to investigate whether lungs can utilize 5-hydroxytryptophan (5-HTP), formed elsewhere and transported, for the synthesis of 5-hydroxytryptamine (5-HT). [14C]5-HTP uptake was 7.7 ± 1.1 and 3.9 ± 0.2% by rabbit and rat lungs, respectively, after 1 h of perfusion with 10 μM [14C]5-HTP. There was an increase in the lung uptake of [14C]5-HTP when the lungs were preperfused with 0.5 mM chlorphentermine (CP) and the uptake was low when the lungs were preperfused with 0.1 mM hydroxybenzylhydrazine dihydrochloride (HBH). The perfusate concentration of 5-hydroxyindole acetic acid (5-HIAA) increased significantly (3–4 μg/100 mL) during rabbit lung perfusion with 10 μM [14C]5-HTP and this did not change significantly when the lungs were preperfused with 0.5 mM CP. However, 5-HT increased with time in the perfusate, 5-HT, but not 5-HIAA, was detected in the perfusate and increased with time of perfusion when the rat lungs were perfused either with 10 μM 5-HTP or with 0.5 mM CP and 10 μM 5-HTP. However, no metabolites were detected in either the rabbit lung or rat lung perfusates when they were preperfused with 0.1 mM HBH. Lung contents of 5-HT and 5-HIAA were significantly higher in the rat lungs and only 5-HIAA increased in rabbit lungs after 1 h of perfusion with 10 μM 5-HTP. Preperfusion with 0.5 mM CP resulted in a greater increase in the 5-HT content of both rabbit and rat lungs. When the lungs were preperfused with 0.1 mM HBH, [14C]5-HT formation from [14C]5-HTP was obtunded. Homogenates of rabbit and rat lungs incubated with [14C]5-HTP (10 μM) resulted in the formation of substantial amounts of [14C]5-HT and [14C]5-HIAA. Incubations with CP (0.5 or 1 mM) resulted in significant increases of 5-HT levels and a corresponding significant reduction in 5-HIAA levels. On the other hand, incubations with HBH (0.1 mM) resulted in significant inhibition of 5-HT and 5-HIAA formation. 5-HT formation from 5-HTP by rat and rabbit lungs in in vitro incubations is in consonance with the perfusion experiments. These results provide evidence that lung can synthesize 5-HT from the circulating 5-HTP, and pulmonary contribution of 5-HT to the circulating levels is possible.
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Watson, Kal E., Gilad S. Segal e Robert L. Conhaim. "Negative pressure ventilation enhances acinar perfusion in isolated rat lungs". Pulmonary Circulation 8, n.º 1 (28 de dezembro de 2017): 204589321775359. http://dx.doi.org/10.1177/2045893217753596.
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We compared acinar perfusion in isolated rat lungs ventilated using positive or negative pressures. The lungs were ventilated with air at transpulmomary pressures of 15/5 cm H2O, at 25 breaths/min, and perfused with a hetastarch solution at Ppulm art/PLA pressures of 10/0 cm H2O. We evaluated overall perfusability from perfusate flows, and from the venous concentrations of 4-µm diameter fluorescent latex particles infused into the pulmonary circulation during perfusion. We measured perfusion distribution from the trapping patterns of those particles within the lung. We infused approximately 9 million red fluorescent particles into each lung, followed 20 min later by an infusion of an equal number of green particles. In positive pressure lungs, 94.7 ± 2.4% of the infused particles remained trapped within the lungs, compared to 86.8 ± 5.6% in negative pressure lungs ( P ≤ 0.05). Perfusate flows averaged 2.5 ± 0.1 mL/min in lungs ventilated with positive pressures, compared to 5.6 ± 01 mL/min in lungs ventilated with negative pressures ( P ≤ 0.05). Particle infusions had little effect on perfusate flows. In confocal images of dried sections of each lung, red and green particles were co-localized in clusters in positive pressure lungs, suggesting that acinar vessels that lacked particles were collapsed by these pressures thereby preventing perfusion through them. Particles were more broadly and uniformly distributed in negative pressure lungs, suggesting that perfusion in these lungs was also more uniformly distributed. Our results suggest that the acinar circulation is organized as a web, and further suggest that portions of this web are collapsed by positive pressure ventilation.
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Hybertson, Brooks M., Roger P. Kitlowski, Eric K. Jepson e John E. Repine. "Supercritical fluid-aerosolized vitamin E pretreatment decreases leak in isolated oxidant-perfused rat lungs". Journal of Applied Physiology 84, n.º 1 (1 de janeiro de 1998): 263–68. http://dx.doi.org/10.1152/jappl.1998.84.1.263.
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Hybertson, Brooks M., Roger P. Kitlowski, Eric K. Jepson, and John E. Repine. Supercritical fluid-aerosolized vitamin E pretreatment decreases leak in isolated oxidant-perfused rat lungs. J. Appl. Physiol. 84(1): 263–268, 1998.—We hypothesized that direct pulmonary administration of supercritical fluid-aerosolized (SFA) vitamin E would decrease acute oxidative lung injury. We previously reported that rapid expansion of supercritical CO2 formed respirable particles of vitamin E and that administering SFA vitamin E to rats increased lung vitamin E levels and decreased neutrophil-mediated lung leak. In the present investigation, we found that pretreatment with SFA vitamin E protected isolated rat lungs against the oxidant-induced lung leak caused by perfusion with xanthine oxidase (XO) and purine, an enzyme system that generates superoxide anion ([Formula: see text]) and hydrogen peroxide. SFA vitamin E droplets were 0.7–3 μm in diameter, and inhalation of the airborne droplets for 30 min deposited ∼55 μg of vitamin E in rat lungs. Isolated rat lungs perfused with XO (0.02 U/ml) and purine (10 mM) gained more weight (1.75 ± 0.12 g, n = 8), retained more Ficoll (11.5 ± 1.2 mg/left lung, n = 7), and accumulated more Ficoll in their lung lavages (700 ± 146 μg/ml, n = 8) than control lungs [0.25 ± 0.06 g ( n = 10), 6.2 ± 1.2 mg/left lung ( n = 9), and 141 ± 31 μg/ml ( n = 8), respectively, P < 0.05]. In contrast, isolated lungs from rats that were pretreated with SFA vitamin E had decreased ( P < 0.05) weight gains (0.32 ± 0.06 g, n = 7), Ficoll retentions (3.3 ± 1.1 mg/left lung, n = 7), and lung lavage Ficoll concentrations (91 ± 26 μg/ml, n = 6) after perfusion with XO and purine compared with isolated lungs from control rats perfused with XO and purine. This protective effect was not observed in rat lungs given sham treatments (CO2 alone or vitamin E acetate aerosolized with supercritical CO2). Our results suggest that direct pulmonary supplementation of vitamin E decreases susceptibility to vascular leakage caused by XO-derived oxidants.
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Zhou, Wenyong, e Yi-Wei Tang. "SG-APSIC1203: Detection of carbapenemase genes in donor lungs at the point of care before transplantation reduces the risk of carbapenem-resistant Enterobacteriaceae–associated donor-derived infection in lung-transplant recipients". Antimicrobial Stewardship & Healthcare Epidemiology 3, S1 (fevereiro de 2023): s25. http://dx.doi.org/10.1017/ash.2023.76.
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Objectives: The number of lung transplants is increasing year by year in China and globally. With the widespread use of donation after brainstem death (DBD) donor lungs and donation after circulatory death (DCD) donor lungs, donor-derived infection (DDI) poses a major challenge in lung transplantation. Using donor lungs infected or colonized with carbapenem-resistant Enterobacteriaceae (CRE) may have serious implications in lung-transplant recipients. Currently, traditional microbial culture along with antimicrobial susceptibility testing cannot fully meet the need for rapid and accurate diagnosis of CRE infection in a donor before organ harvest. Methods: The Xpert Carba-R device (Cepheid, Sunnyvale, CA) was used to detect and differentiate Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron-encoded metallo-β-lactamase (VIM), active-on-imipenem (IMP), and OXA-48 carbapenemase genotypes in bronchial lavage fluid from donor lungs before organ harvest. Positive detection of 1 or more of these genotypes indicated a potentially CRE-infected donor lung, and these organs were removed from the lung transplantation cohort. Donor lungs negative for all KPC, NDM, VIM, IMP, and OXA-48 genotypes determined by the Xpert Carba-R device were used for lung transplantation. The incidence of CRE-associated DDI and infection-related complications were compared in the Xpert Carba-R screening group and an historic control group. Results: In this study, 21 donor lungs were tested with the Xpert Carba-R device to detect and differentiate carbapenemase genotypes. Among them, 4 were positive for 1 or more carbapenemase genotypes and were discarded, and the remaining 17 donor lungs showing no carbapenemase gene presence were used for lung transplantation. No CRE-associated DDI occurred in these 17 lung-transplant recipients. Conclusions: Rapid and accurate detection of the carbapenemase gene in donor lungs at the point of care before transplantation using the Xpert Carba-R device reduced the risk of CRE-associated DDI in lung-transplant recipients.
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Hasan, Farukh, Azizur Rahman e Zeenat Idreesi. "Pathogenesis of Amraz-e-Riya (Lung Disease) in Unani Medicine - A Review". International Journal of Science and Healthcare Research 9, n.º 2 (1 de julho de 2024): 373–77. http://dx.doi.org/10.52403/ijshr.20240248.
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Background & objective: In the Unani system of medicine (USM), the lungs are considered an essential organ that plays a crucial role in maintaining health by respiration. The lungs are closely associated with the sanguine humour, and, any imbalance in this humour may lead to various respiratory disorders and other health issues. In USM, the diseases are understood based on Asbāb (Causes), Alamat (signs, and symptoms), and Mahiyat-e-Mardi (pathogenesis). This study aims to describe the pathogenesis of Amraz-e-Riya (lung disease) for a better understanding of the disease and proper treatment. Methodology: Literature related to the pathogenesis of lung disease was surveyed from classical books of Ṭibb-i-Unani, their translations, commentaries, previous dissertations, journals, proceedings, etc. Result and conclusion: Unani physicians explained respiration is completed by two movements and two resting phases. The inhaled air moderates the heat of Rūḥ(Pneuma), which is very important for maintaining health and life because its disturbance has immediate consequences on health. By exhalation, the lungs expel smoky vapours from the body because inappropriate or bad air is likely to dissolve the Ḥarārat Gharīziyya (innate heat). So, it can be concluded that respiration plays an important role in the survival and continuation of life. Keywords: Lung’s pathogenesis, lung temperament, Pneumonia, Pleurisy, phthisis, Unani medicine.
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Bryan, C. L., A. J. Patefield, D. Cohen, J. L. Nielsen, B. Emanuel e J. H. Calhoon. "Assessment of injury in transplanted and nontransplanted lungs after 6 h of cold storage with glutathione". Journal of Applied Physiology 76, n.º 3 (1 de março de 1994): 1232–41. http://dx.doi.org/10.1152/jappl.1994.76.3.1232.
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Single-lung transplantation after 3 h of hypothermic storage produces bilateral lung injury [pulmonary reimplantation response (PRR)]. We hypothesized that glutathione (GSH) hypothermic storage would protect both lungs from PRR for extended preservation times and that differences in injury and protection would be realized between the graft and the nontransplanted lung. Mongrel dogs underwent left single-lung autotransplantation after preservation for 5–6 h in Euro-Collins (EC) solution, EC plus exogenous GSH (EC+GSH), or Viaspan (VIA) at 4 degrees C. Lung injury was measured in both lungs after 1 h of reperfusion. EC dogs demonstrated significant increases in lung edema, lipid peroxidation, and alveolar neutrophil recruitment in the lung graft and to a less extent in the nontransplanted right lung compared with control dogs (P < 0.05). Edema, lipid peroxidation, and alveolar neutrophils were significantly reduced in both lungs from EC+GSH and VIA dogs compared with lungs from EC dogs (P < 0.05). An increase in large-pore permeability was measured in the lung graft from EC dogs compared with all other lungs. Bronchoalveolar lavage fluid lactate dehydrogenase and total protein concentrations were elevated in both lungs from all three groups of tranplanted dogs compared with those of control dogs (P < 0.05). These data suggest that GSH-containing solutions attenuate the PRR after 6 h of ischemic hypothermic storage but that the protection is incomplete. Mechanisms of injury affecting the lung graft during the PRR appear to differ from those affecting the nontransplanted lung.
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Jackson, R. M., W. J. Russell e C. F. Veal. "Endogenous and exogenous catalase in reoxygenation lung injury". Journal of Applied Physiology 72, n.º 3 (1 de março de 1992): 858–64. http://dx.doi.org/10.1152/jappl.1992.72.3.858.
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Reexpansion pulmonary edema parallels reperfusion (reoxygenation) injuries in other organs in that hypoxic and hypoperfused lung tissue develops increased vascular permeability and neutrophil infiltration after reexpansion. This study investigated endogenous lung catalase activity and H2O2 production during hypoxia (produced by lung collapse) and after reoxygenation (resulting from reexpansion), in addition to assessing the effects of exogenous catalase infusion on the development of unilateral pulmonary edema after reexpansion. Lung collapse resulted in a progressive increase in endogenous catalase activity after 3 (14%) and 7 days (23%), while activities in contralateral left lungs did not change (normal left lungs averaged 180 +/- 11 units/mg DNA). Tissue from control left lungs released H2O2 into the extracellular medium at a rate calculated to be 242 +/- 34 nmol.h-1.lung-1. No significant change in extracellular release of H2O2 occurred after 7 days of right lung collapse. However, after reexpansion of the previously collapsed right lungs for 2 h, H2O2 release from both reexpanded right and contralateral left lungs significantly increased (88 and 60%, respectively) compared with controls. Infusion of exogenous catalase significantly increased plasma and lung catalase activities. Exogenous catalase infusion prevented neither the increase in lung permeability nor the infiltration with neutrophils that typically occurs in reexpanded lungs. These data indicate that lung hypoxia/reoxygenation, induced by sequential collapse and reexpansion, has specific effects on endogenous lung catalase activity and H2O2 release. However, exogenous catalase does not prevent reexpansion pulmonary edema, eliminating extracellular (but not intracellular) H2O2 as an important mediator of unilateral lung injury in this model.
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Ajayi, Funmilayo O., e David T. Okpako. "Demonstration of prostaglandin activity in longs of the rainbow lizard (Agama agama) by bioassay". Canadian Journal of Physiology and Pharmacology 68, n.º 6 (1 de junho de 1990): 744–48. http://dx.doi.org/10.1139/y90-113.
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Extracts and perfusate effluents of lungs of the rainbow lizard (Agama agama) were assayed for prostaglandin-like activity. Results of differential bioassay and thin-layer chromatography suggested that the prostanoid was predominantly PGE2-like. The mean PGE2-like content of 10 lizard lung extracts was 2.9 μg g−1 wet weight compared with 146 ng g−1 in rat lungs. Mechanical pressure applied to the lung during perfusion through the pulmonary vasculature provoked the release of large quantities of PGE2-like material. This release was blocked by fatty acid cyclooxygenase inhibitors. Compared with guinea-pig and rat lungs, lizard lungs exhibited a markedly low capacity for inactivating PGE2. In view of an apparently high prostaglandin-forming and a low inactivating capacity, we speculate that under certain circumstances, lizard lungs may release vasoactive substances into the circulation.Key words: rainbow lizard, cyclooxygenase, PGE2 lung inactivation.
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Herbein, Joel F., e Jo Rae Wright. "Enhanced clearance of surfactant protein D during LPS-induced acute inflammation in rat lung". American Journal of Physiology-Lung Cellular and Molecular Physiology 281, n.º 1 (1 de julho de 2001): L268—L277. http://dx.doi.org/10.1152/ajplung.2001.281.1.l268.
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Pulmonary surfactant participates in the regulation of alveolar compliance and lung host defense. Surfactant homeostasis is regulated through a combination of synthesis, secretion, clearance, recycling, and degradation of surfactant components. The extracellular pool size of surfactant protein (SP) D fluctuates significantly during acute inflammation. We hypothesized that changes in SP-D levels are due, in part, to altered clearance of SP-D. Clearance pathways in rats were assessed with fluorescently labeled SP-D that was instilled into control lungs or lungs that had been treated with lipopolysaccharide (LPS) 16 h earlier. SP-D clearance from lavage into lung tissue was time dependent from 5 min to 1 h and 1.7-fold greater in LPS-treated lungs than in control lungs. Analysis of cells isolated by enzymatic digestion of lung tissue revealed differences in the SP-D-positive cell population between groups. LPS-treated lungs had 28.1-fold more SP-D-positive tissue-associated neutrophils and 193.6-fold greater SP-D association with those neutrophils compared with control lungs. These data suggest that clearance of SP-D into lung tissue is increased during inflammation and that tissue-associated neutrophils significantly contribute to this process.
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Nelson, Alexander J., e Yee Ling Wu. "Allergen inhalation transforms the lungs into a permissive environment for local IgE responses". Journal of Immunology 210, n.º 1_Supplement (1 de maio de 2023): 156.05. http://dx.doi.org/10.4049/jimmunol.210.supp.156.05.
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Abstract Immunoglobulin E (IgE) is the primary cause of allergic diseases and must be tightly regulated. Production of IgE occurs when activated B cells undergo class switch recombination (CSR) to IgE. These key events are rare, thus questions on which B cell subsets undergo IgE CSR, where IgE CSR predominantly occurs, and which molecular and cellular signals promote IgE CSR remain unresolved. We modeled allergic asthma by intranasal administration of ragweed pollen and ovalbumin (OVA) in mice, and found that allergen inhalation induced the formation of lymphoid aggregates and production of OVA-specific IgE in the lungs. Using fluorescent mice reporting IgE switching, we revealed that allergen-sensitized lungs were a major site of IgE CSR with IgG1 +memory B cells (MBCs) being the dominant IgE-switching cells. Single-cell transcriptomics and flow cytometry analyses revealed a tight correlation between CCR6 expression and lung IgG1 +MBCs, potentially explaining their recruitment/retention in the respiratory mucosa. Furthermore, lungMBCs underwent IgE CSR more frequentlythan MBCs in the draining lymph nodes or spleen. Since IgE CSR requires interleukin 4 (IL-4), we used IL-4 reporter mice and found that IL-4-producing T H2 cells were enriched in the lungs compared with lymphoid organs. Co-culture experiments using purified lung MBCs from IgE reporter mice with lung or splenic effector CD4 +T cells revealed that IgE CSR was elevated in the presence of lungT cells, suggesting lung-infiltrating T H2 cells drive elevated IgE CSR in the lungs. This study clarifies that the respiratory mucosa is a key site of IgE CSR – in allergic asthma the lung environment supports IgE CSR with IgG1 +MBCs and CD4 +T cells collaborating to promote local IgE responses. Supported by grants from NIH (F31 HL156459, T32 AI007508, R01 HL165120, R21 AI159456)
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Ranaweera, Lanka, W. N. Sulani e W. L. R. L. Nanayakkara. "Morphological variations of human pulmonary fissures: an anatomical cadaveric study in Sri Lanka". Italian Journal of Anatomy and Embryology 126, n.º 1 (21 de setembro de 2022): 161–69. http://dx.doi.org/10.36253/ijae-12675.
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The aim of this study was to identify morphological and morphometric variations of pulmonary fissures. A sample of 50 adult formalin fixed Sri Lankan cadaveric lungs (24 left and 26 right lungs) were observed with the help of magnifying glass and length measurements of the lung fissures were taken using a measuring tape. Complete oblique fissure was seen in 16 (66.67%) left lungs and 11 (42.3%) right lungs. Incomplete oblique fissure was seen in 8 (33.33%) left lungs and 15 (57.69%) right lungs. There was complete absent of horizontal fissure in 4 (15.38%) right lungs whereas rest of the 22 right lungs indicated incomplete horizontal fissure (84.61%). The mean lengths of the left oblique fissure, right oblique fissure and horizontal fissure were 26.88±5.88cm, 27.31±6.04 cm and 8.31±3.61 cm, respectively. Incomplete fissure was the most common variant of the fissures in the analyzed sample. There was a high prevalence of incomplete horizontal fissure of right lung followed by incomplete right and left oblique fissures. Absence of oblique fissure was not found in either left or right lungs. The mean length of right oblique fissure was slightly greater than the mean length of left oblique fissure. The knowledge lung fissures, indeed help clinicians and radiologists to identify alterations of the disease distribution and to reduce the misinterpretation of radiological modalities as well as to arrive at an accurate diagnosis with plan of management of a patient.
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Egan, Thomas. "How Should Lungs Be Allocated for Transplant?" Seminars in Respiratory and Critical Care Medicine 39, n.º 02 (26 de março de 2018): 126–37. http://dx.doi.org/10.1055/s-0037-1620265.
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AbstractAs lung transplantation became established therapy for end-stage lung disease, there were not nearly enough suitable lungs from brain-dead organ donors to meet the need, leading to a focus on how lungs are allocated for transplant. Originally lungs were allocated by the United Network for Organ Sharing (UNOS) like hearts—by waiting time, first to listed recipients in the organ procurement organization of the donor, then to potential recipients in concentric 500 nautical mile circles. This resulted in long waiting times and increasing waitlist deaths. In 1999, the Health Resources and Services Administration published a Final Rule, requesting UNOS to review organ allocation algorithms to ensure that they complied with the desire to allocate organs based on urgency, avoiding futile transplants, and minimizing the role of waiting time in organ allocation. This led to development of the lung allocation score (LAS), which allocates lungs based on urgency and transplant benefit, introduced in 2005. The U.S. LAS system was adopted by Eurotransplant to allocate unused lungs between donor countries, and by both Germany and the Netherlands for lung allocation in their countries. This article will review the history of lung allocation, discuss the impact of LAS and its shortcomings, suggest recommendations to increase the number of lungs for transplant, and improve allocation of donated lungs. Ultimately, the goal of organ transplant research is to have so many organs to transplant that allocation systems are unnecessary.
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Kambara, K., K. E. Longworth, V. B. Serikov e N. C. Staub. "Effect of interstitial edema on lung lymph flow in goats in the absence of filtration". Journal of Applied Physiology 72, n.º 3 (1 de março de 1992): 1142–48. http://dx.doi.org/10.1152/jappl.1992.72.3.1142.
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We tested the effect of interstitial edema on lung lymph flow when no filtration occurred. In 16 anesthetized open-thorax ventilated supine goats, we set pulmonary arterial and left atrial pressures to nearly zero and measured lymph flow for 3 h from six lungs without edema and ten with edema. Lymph flow decreased exponentially in all experiments as soon as filtration ceased. In the normal lungs the mean half time of the lymph flow decrease was 12.7 +/- 4.8 (SD) min, which was significantly shorter (P less than 0.05) than the 29.1 +/- 14.8 min half time in the edematous lungs. When ventilation was stopped, lymph flow in the edematous lungs decreased as rapidly as in the normal lungs. The total quantity of lymph after filtration ceased was 2.7 +/- 0.8 ml in normal lungs and 9.5 +/- 6.3 ml in edematous lungs, even though extravascular lung water was doubled in the latter (8.4 +/- 2.4 vs. 3.3 +/- 0.4 g/g dry lung, P less than 0.01). Thus the maximum possible clearance of the interstitial edema liquid by the lymphatics was 6.3 +/- 4.8%. When we restarted pulmonary blood flow after 1–2 h in four additional goats, lymph flow recovered within 30 min to the baseline level. These findings support the hypothesis that lung lymph flow originates mainly from alveolar wall perimicrovascular interstitial liquid and that the contribution of the lung lymphatic system to the clearance of interstitial edema (bronchovascular cuffs, interlobular septa) is small.
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Tetenev, K. F., F. F. Tetenev, T. S. Ageyeva, T. N. Bodrova, A. I. Karzilov e P. Ye Mesko. "MECHANISMS OF COUNTERACTING FLAP-VALVE BRONCHIAL OBSTRUCTION IN CASE OF OBSTRUCTIVE PULMONARY EMPHYSEMA". Bulletin of Siberian Medicine 14, n.º 4 (28 de agosto de 2015): 75–81. http://dx.doi.org/10.20538/1682-0363-2015-4-75-81.
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The research goal was to formulate and substantiate the hypothesis explaining support for an expiratory air flow in case of pulmonary emphysema. The research method consisted in comparing the mechanical properties of lungs in practically healthy individuals (37 individuals, mean age – (30.4 ± 1.7) y.o.) and COPD patients with pronounced lung emphysema (30 patients, mean age – (52.1 ± 2.3) y.o.) as well as those of isolated normal lungs (n = 14) and isolated lungs of patients who died of COPD (n = 5). Pulmo-nary mechanics was studied via the simultaneous measurement of transpulmonary pressure and lung ven-tilation volume. General lung hysteresis and elastic lung hysteresis were calculated. The mechanical properties of isolated lungs were studied using passive ventilation under the Donders bell. The air flow was interrupted in order to measure alveolar pressure and develop an elastic lung hysteresis curve. Pres-sure in the Donders bell was changed by means of a special pump in automatic and manual modes. The research has not revealed any fundamental differences between the mechanical properties of the normal and emphysematous lungs. A minimum increase in the pressure inside the Donders bell over atmospheric pressure used to stop air ejection in both normal and the emphysematous lungs as the result of flap-valve bronchial obstruction. In living beings, air is ejected from lungs with an increase in pressure under the conditions of forced expiration. Pressure increases up to (38.6 ± 2.71) cm H2O in healthy individuals and up to (20.5 ± 1.86) cm H2O in COPD patients. Probably, an expiratory air flow is supported by active expiratory bronchial dilatation that counteracts flap-valve bronchial obstruction. The hypothesis is based on the confirmed ability of the lungs to perform inspiratory actions (in addition to the action of respiratory muscles) and the theory of mechanical lung activity.
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Yan, Xiao, Juan Jose Polo Carbayo, Ewald R. Weibel e Connie C. W. Hsia. "Variation of lung volume after fixation when measured by immersion or Cavalieri method". American Journal of Physiology-Lung Cellular and Molecular Physiology 284, n.º 1 (1 de janeiro de 2003): L242—L245. http://dx.doi.org/10.1152/ajplung.00184.2002.
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Organ volume is a critical parameter in morphometric analysis. The special problems of the lung as a nonsolid organ are overcome by tracheal instillation of fixatives at a constant airway pressure (Paw). Lung volume can change significantly after fixation as Paw change. To determine the variation of lung volume after fixation, we measured the volume of intact fixed lungs by serial immersion in saline (Vimm) at selected time points, compared with measurements obtained by point counting [Cavalieri Principle (Vcav)] after tissue sectioning to release Paw. Vimm was systematically higher than Vcav by 25% in dog lungs and 13% in guinea pig lungs ( P = 0.0003 between species). This size-dependent variability reflects residual elastic recoil, refolding and/or crumpling of alveolar septa after fixation. Vimm remained 14% higher than Vcav in dog lungs even after pressure release. Vcav/Vimmwas systematically lower in the upper than the lower strata of the same lung. We conclude that Vcav measured on lung slices after relaxation of Paw more precisely represents the state of the tissue to be used for subsequent morphometric analysis, particularly for large lungs.
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Jackson, R. M., C. F. Veal, C. B. Alexander, A. L. Brannen e J. D. Fulmer. "Neutrophils in reexpansion pulmonary edema". Journal of Applied Physiology 65, n.º 1 (1 de julho de 1988): 228–34. http://dx.doi.org/10.1152/jappl.1988.65.1.228.
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This study investigated the possible contribution of neutrophils to development of reexpansion pulmonary edema (RPE) in rabbits. Rabbits' right lungs were collapsed for 7 days and then reexpanded with negative intrathoracic pressure for 2 h before study, a model that creates unilateral edema in the reexpanded lungs but not in contralateral left lungs. Two hours after lung reexpansion, significant increases in lavage albumin concentration (17-fold), percent neutrophils (14-fold), and total number of neutrophils (7-fold) recovered occurred in the reexpanded lung but not in the left. After 2 h of reexpansion increased leukotriene B4 was detected in lavage supernatant from right lungs (335 +/- 33 pg/ml) compared with the left (110 +/- 12 pg/mg, P less than 0.01), and right lung lavage acid phosphatase activity similarly increased (6.67 +/- 0.35 U/l) compared with left (4.73 +/- 0.60 U/l, P less than 0.05). Neutropenia induced by nitrogen mustard (17 +/- 14 greater than neutrophils/microliters) did not prevent RPE, because reexpanded lungs from six neutropenic rabbits were edematous (wet-to-dry lung weight ratio 6.34 +/- 0.43) compared with their contralateral lungs (4.97 +/- 0.04, P less than 0.01). An elevated albumin concentration in reexpanded lung lavage from neutropenic rabbits (8-fold) confirmed an increase in permeability. Neutrophil depletion before reexpansion did not prevent unilateral edema, although neutrophils were absent from lung sections and alveolar lavage fluid from neutropenic rabbits.
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Jones, David R., Randy M. Becker, Steve C. Hoffmann, John J. Lemasters e Thomas M. Egan. "When does the lung die?K fc, cell viability, and adenine nucleotide changes in the circulation-arrested rat lung". Journal of Applied Physiology 83, n.º 1 (1 de julho de 1997): 247–52. http://dx.doi.org/10.1152/jappl.1997.83.1.247.
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Jones, David R., Randy M. Becker, Steve C. Hoffmann, John J. Lemasters, and Thomas M. Egan. When does the lung die? K fc, cell viability, and adenine nucleotide changes in the circulation-arrested rat lung. J. Appl. Physiol. 83(1): 247–252, 1997.—Lungs harvested from cadaveric circulation-arrested donors may increase the donor pool for lung transplantation. To determine the degree and time course of ischemia-reperfusion injury, we evaluated the effect of O2 ventilation on capillary permeability [capillary filtration coefficient ( K fc)], cell viability, and total adenine nucleotide (TAN) levels in in situ circulation-arrested rat lungs. K fc increased with increasing postmortem ischemic time ( r = 0.88). Lungs ventilated with O2 1 h postmortem had similar K fc and wet-to-dry ratios as controls. Nonventilated lungs had threefold ( P < 0.05) and sevenfold ( P < 0.0001) increases in K fc at 30 and 60 min postmortem compared with controls. Cell viability decreased in all groups except for 30-min postmortem O2-ventilated lungs. TAN levels decreased with increasing ischemic time, particularly in nonventilated lungs. Loss of adenine nucleotides correlated with increasing K fc values ( r = 0.76). This study indicates that lungs retrieved 1 h postmortem may have normal K fc with preharvest O2 ventilation. The relationship between K fc and TAN suggests that vascular permeability may be related to lung TAN levels.
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MAITLAND, DAVID P., e ARTHUR MAITLAND. "PENETRATION OF WATER INTO BLIND-ENDED CAPILLARY TUBES AND ITS BEARING ON THE FUNCTIONAL DESIGN OF THE LUNGS OF SOLDIER CRABS MICTYRIS LONGICARPUS". Journal of Experimental Biology 163, n.º 1 (1 de fevereiro de 1992): 333–44. http://dx.doi.org/10.1242/jeb.163.1.333.
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Soldier crabs, Mictyris longicarpus Latreille, inhabit intertidal sand-flats of Eastern Australia. Their gill chambers are modified for both water circulation and air-breathing. Water circulates through the lower gill compartments. The upper regions of the gill chambers are air-filled and function as lungs. The deep vascular parenchyma lining the upper gill chambers, or lungs, is penetrated by a regular series of fine branching airways. Scanning electron micrographs of lung architecture are shown. Measurements relating to lung structure were made on plastic casts. Because of the lung's design, water circulating through the lower gill compartments does not interfere with lung function. The airways are blind-ended and nonanastomosing, acting in effect as air-filled capillary tubes sealed at one end. A mathematical model and explanation show how the air trapped within this lung structure substantially reduces water penetration, despite surface tension (capillary) processes. This same lung design also facilitates the shedding of the lung cuticle at each moult. Note: Present address: Department of Physiology, Medical School, University of Witwatersrand, Parktown, Johannesburg, South Africa 2193.