Postmortem Examination Of Lungs Research Articles

Патологическая анатомия поражения сосудов легких при COVID-19

Pathological anatomy of pulmonary vascular lesions plays a key role in understanding the patho-genesis and morphogenesis of COVID-19. This review focuses on morphological features of pulmonary vascular injury in COVID-19. The virus is known to be capable of causing not only cytopathic cell damage of various organs and tissues (type II pneumocytes, cardiomyocytes, neurons, epithelial cells of the gas-trointestinal tract) but also endotheliotropic damage that aggravates the development and course of acute alveolar damage to the lungs. We studied the literature on microscopic changes in the vessel walls in lung tissue for 2020–2022. This review discusses the issues of local or systemic vascular lesions, morphologi-cal changes in the vessels over time, the likelihood of the development of microangiopathy, vasculitis, and endotheliitis in COVID-19 patients. Particular attention is paid to possible mechanisms of endotheliopathy in COVID-19 patients and its role in the microthrombi genesis. We speculate that in the future, postmor-tem lung examination in COVID-19 patients using histological, histochemical, and immunohistochemical methods will clarify the features of alterative and inflammatory changes and reparative processes in the blood vessel walls, as well as neoangiogenesis at different stages of the disease. Keywords: pathological anatomy, COVID-19, lungs, endotheliopathy, endotheliitis, microthrombus formation

Prevalence of ovine pulmonary adenocarcinoma (Jaagsiekte) in a UK slaughterhouse sheep study

Jaagsiekte sheep retrovirus (JSRV) causes ovine pulmonary adenocarcinoma (OPA or Jaagsiekte), a disease of increasing concern to sheep farmers. It is an infectious lung cancer caused by viral transformation of...

Fatal Outcomes in Family Transmission of Mycoplasma pneumoniae

Mycoplasma pneumoniae continues to be a significant cause of community-acquired pneumonia and, on rare occasions, manifests as fulminant disease that leads to mortality, even in healthy individuals. We conducted a retrospective study on members of a family who were quarantined by the Centers for Disease Control and Prevention in 2002 for respiratory failure and death of a 15-year-old brother (sibling 1) and a 13-year-old sister (sibling 2). Collected airway, cerebrospinal fluid (CSF), and serum samples from both deceased siblings and serum samples from both parents and the remaining 3 ill siblings (sibling 3-5) were tested using a range of diagnostic assays. Autopsy lung tissue samples from sibling 2 were also assessed using immunohistochemical and immunoelectron microscopic methods. Autopsy evaluation of sibling 1 revealed cerebral edema consistent with hypoxic ischemic encepatholopathy and pulmonary findings of bronchiolitis obliterans with organizing pneumonia (BOOP). Postmortem lung examination of sibling 2 revealed lymphoplasmacytic bronchiolitis with intraluminal purulent exudate, BOOP, and pulmonary edema. Results of diagnostic assays implicated the household transmission of M. pneumoniae among all 5 siblings and both parents. Further analysis of lung tissue from sibling 2 demonstrated the presence of M. pneumoniae organisms and community-acquired respiratory distress syndrome toxin. M. pneumoniae was cultured directly from sibling 2 autopsy lung tissue. Evidence is provided that M. pneumoniae was readily transmitted to all members of the household and that the resulting infections led to a spectrum of individual responses with variation in disease progression, including lymphoplasmacytic bronchiolitis, BOOP, and death.

Inhaled nitric oxide improves survival in the rat model of high-altitude pulmonary edema

High-altitude pulmonary edema (HAPE) afflicts certain individuals after a rapid gain in elevation. Those susceptible demonstrate an exaggerated hypoxic pulmonary vasoconstrictive response. This causes pulmonary hypertension, which may disrupt vascular integrity. This experiment was designed to test whether inhaled nitric oxide would affect development of HAPE in a rat model. Subjects were exposed in a hypobaric chamber to a simulated altitude of 6200 m (barometric pressure = 380 mm Hg, fraction of inspired oxygen = 0.19) for 24 hours. Control animals (n = 48) spontaneously breathed a mixture of 90% room air and 10% nitrogen, whereas the nitric oxide group (n = 48) received a similar mixture containing 83 ppm nitric oxide. Postmortem examination of lungs was performed for light microscopy, total hemoglobin, and gravimetric estimates of water content. Mortality was 39.5% (n = 19) in control animals and 6.2% (n = 3) in the nitric oxide group (P < .001). Both groups significantly increased their lung weight-body weight ratio. Percentage of lung water was similar in both groups despite increases in lung weight, which is consistent with the protein-rich edema characteristic of HAPE. Light microscopic examination of survivors' lungs in both groups revealed scattered alveolar hemorrhage. No significant cellular inflammatory response was present. We conclude that inhaled nitric oxide improves survival in the rat model of HAPE.

The diagnosis of ventilator-associated pneumonia using non-bronchoscopic, non-directed lung lavages.

(1)To assess the diagnostic utility of quantitative cultures of non-bronchoscopic lung lavage (NBL) in ventilator-associated pneumonia and evaluate the role of the Bacterial Index; (2) To assess the predictive value of NBL surveillance quantitative cultures in ventilated patients; (3) To evaluate the Clinical Pulmonary Infection Score (CPIS) system in ventilated patients. A prospective comparison of NBL with bronchoscopic bronchoalveolar lavage and protected specimen brush. Three intensive care units in academic tertiary care centres. 145 adults ventilated for 72 h, with and without clinical signs of pneumonia. Sampling of lower airway secretions by NBL, bronchoalveolar lavage and protected specimen brush. Diagnostic reliability of quantitative cultures, Bacterial Index and CPIS. 34 episodes of clinical ventilator-associated pneumonia were documented in 32 patients. 9 episodes were confirmed by concordant blood/pleural culture or post-mortem lung examination. Qualitative concordance of the predominant pathogen between sequential NBL: bronchoalveolar lavage and protected specimen brush was 83 %. Sensitivity and specificity of non-directed bronchial lavage at a threshold of 10(4) CFU/ml were 68 % and 70 % respectively (p = 0. 003) and were comparable with the bronchoscopic methods. However, the low positive predictive value of NBL indicates that quantitation in the absence of clinical signs is unlikely to be useful. Bacterial Index did not improve discriminatory power of quantitation compared with bacterial load of predominant organism. Mean CPIS for confirmed pneumonia cases was 8.4 +/- 1.01, significantly higher than for non-pneumonia observations (p = < 0.0001). NBL is a simple, safe, cheap, readily-available method of diagnosing ventilator-associated pneumonia with comparable diagnostic accuracy to bronchoscopic techniques. Quantitation of respiratory tract cultures can exclude pneumonia in patients with equivocal clinical signs. The diagnostic threshold should vary depending on the length of ventilation, likelihood of pneumonia and antibiotic administration. The Bacterial Index is a flawed mathematical device that has no contributory role in pneumonia diagnosis. The CPIS has some diagnostic role in selected cohorts of ventilated patients.

1004-56 Ultrasonic Monitoring of Fat Embolization During Major Orthopedic Procedures: Experimental Studies in Sheep Define a New Utility for Intracardiac Ultrasound

Fat embolism syndrome (FES) has been described following bone injuries of the lower extremities and intramedullary fixation procedures, such as hip replacement and can have serious pulmonary vascular consequences. We performed an intravascular ultrasound (IVUS) study to directly visualize and quantitate the release of marrow contents following femoral fracture and reamed or non reamed intramedullary fixation. One or more portions ofthese orthopedic maneuvers were performed in 30 anesthetized and ventilated sheep, including femoral fracture (F), opening the intramedullary canal (OC), reaming (R)(reamer sized 8, 8.5, 9, 9.5, 10.5, 11 mm in diameter) and nail insertion (N). Thirty sheep were randomized into 3 groups (n = 10): Group 1 (G1) had F, OC, Rand N. Group 2 (G2) had F, OC and N but no reaming. Group 3 (G3) had Fonly. A high resolution 8 French. 15 MHz IVUS catheter (Aloka Co. Ltd.) was placed via the jugular vein to the junction of the inferior vena cava and right atrium (RA). Echogenic embolic particles (EP) visualized entering the RA following each maneuver were quantified by counting the maximal number of EP/video frame, measuring the maximal size of EP and the duration of EP appearance. Small numbers of small particle embolic events were denoted on F alone, but opening through to the canal as the first maneuver in sequence followed by N, produced the largest EP's and the longest duration of showers of emboli in Gl and G2 (p &lt; 0.01). F and all the other procedures involved in intramedullary fixation constantly induced release of marrow contents into the circulation detectable by ultrasound. As other correlates to these observations, a transient increase of pulmonary vascular resistance by mean of 1.3 resistance units was noted in the animals in G1 and more widespread microscopic findings of embolic events were found in G1 and G2 than in G3 at post-mortem lung examination. Our findings may help to explain the mechanism of FES following femoral fracture and intramedullary fixation. The use of IVUS for monitoring EP showers may aid refinement of orthopedic surgical procedures.

The Distinction Between Lung Maturation and Limited Injury in Human Airways: Functional and Morphometric Studies in Postmortem Examination of Lungs

M orphologic alterations occur in the maturing and aging lung. These morphologic alterations are reflected in functional changes which, in the case of the aging lung, are qualitatively similar to those observed in advanced chronic obstructive pulmonary disease (COPD). Any study which attempts to evaluate the morphologic and functional changes of COPD must differentiate that part contributed by disease from that contributed by normal maturation and aging. In this report we attempt to characterize some of the functional and morphologic alterations in the airways of human nondiseased lungs over a wide age range as a basis for understanding additional changes which may be produced by disease, particularly those in early COPD. Studies of mechanics and morphometry were performed in postmortem examination of human lungs. Left lungs are obtained from male victims of sudden nonhospital death on whom autopsies were performed in the coroner’s office. Usual causes of death include traffic accidents, myocardial infarction and exsanguinating gunshot wounds. Stringent criteria are used in selecting the lungs. Lungs heavier than 450 gm are not accepted because they usually have microscopic evidence of edema. Similarly, lungs with hemorrhage, large pleural rents or excessive bronchial secretions are not used. Mechanics are studied immediately after obtaining the lung, and in all cases are completed within 24 hours of the person’s death. The lung is suspended by a bronchial cannula in a glass plethysmograph. Measurements of lung mechanics include static elastic recoil pressures, total pulmonary resistance by the method of Mead and Whittenberger,’ dynamic compliance and flow volume plots from passive and forced deflations. Barium sulfate is then insufflated into the bronchial tree and the mean diameter of all segmental bronchi is determined from the bronchogram. This value is considered a relative measure of the size of the central airways. The lung is inflated and fixed in formalin at 25-cm water pressure. Lung slices are carefully examined, and the amount of emphysema, if present, is determined by point count. Random histologic sections are obtained from which the number and mean diameter of all membranous bronchioles of less than 2 mm in diameter are determined. Mucous plugging in the peripheral airways is evaluated by quantitatively determining the proportion of bronchiolar lumen occupied by mucus on histologic section. Approximately 50 bronchioles are evaluated in each lung. The proportion of bronchial mucous gland is quantitatively determined from sections of lobar bronchi. The results reported are from the first 26 lungs studied. The age of the donors ranges from 10-82 years. Mild emphysema, less than 10 percent by gross point count, is present in five lungs. The population studied can be considered a reasonable cross section of an urban population, consisting of persons with normal and mildly diseased lungs. The relationship between the flow resistive properties of the lungs and measurements of airway caliber at different levels of the bronchial tree can be summarized as follows: A statistically significant (p <0.05) but weak correlation (R 0.39) is found between mean segment diameter and the reciprocal of pulmonary resistance, conductance. In contrast, a very close correlation (R 0.90) is found between mean bronchiole diameter and pulmonary conductance. This suggests that mean bronchiole diameter is the main determinant of variations in pulmonary conductance in normal and mildly diseased human lungs. The determination of pulmonary conductance, or resistance, is more sensitive than either maximal expiratory flow rates or dynamic compliance in detecting bronchiolar narrowing. Bronchial mucous gland hyperplasia is one of the pathologic abnormalities described in chronic bronchitis. When mucous glands occupy 15 percent or more of the bronchial wall, they are considered hyperplastic. The percentage of mucous glands in the bronchial wall exceeded this value in 6 of the 26 lungs studied (range 16.1 to 24.1 percent). Functional parameters are not significantly different in this group as compared to the other lungs studied. Emphysema or bronchiolar narrowing is not present in these six lungs, and the amount of mucus in the lumens of the peripheral airways is not increased. No age-related changes are seen in the percentage of bronchial mucous glands in this study. The bronchial mucous gland hyperplasia is not related to any functional abnormalities in this study and is not associated with other pathologic changes commonly found with COPD. The size of the central airways, as reflected by the mean segmental bronchial diameter does not change significantly beyond the age of 20 years (Fig 1). In contrast, highly significant age-related changes occur in the mean diameter of the membranous bronchioles (Fig 2). Maximal bronchiole diameter is not reached until well into the third decade of life, with a variable decrease thereafter. Matsuba and Thurlbeck,2 using nearly iden-

The Distinction Between Lung Maturation and Limited Injury in Human Airways: Functional and Morphometric Studies in Postmortem Examination of Lungs

The Distinction Between Lung Maturation and Limited Injury in Human Airways: Functional and Morphometric Studies in Postmortem Examination of Lungs