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Background Multi‐organ damage is a common feature of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, going beyond the initially observed severe pneumonia. Evidence that the testis is also compromised is growing. Objective To describe the pathological findings in testes from fatal cases of COVID‐19, including the detection of viral particles and antigens, and inflammatory cell subsets. Materials and methods Postmortem testicular samples were obtained by percutaneous puncture from 11 deceased men and examined by reverse‐transcription polymerase chain reaction (RT‐PCR) for RNA detection and by light and electron microscopy (EM) for SARS‐CoV‐2. Immunohistochemistry (IHC) for the SARS‐CoV‐2 N‐protein and lymphocytic and histiocytic markers was also performed. Results Eight patients had mild interstitial orchitis, composed mainly of CD68+ and TCD8+ cells. Fibrin thrombi were detected in five cases. All cases presented congestion, interstitial edema, thickening of the tubular basal membrane, decreased Leydig and Sertoli cells with reduced spermatogenesis, and strong expression of vascular cell adhesion molecule (VCAM) in vessels. IHC detected SARS‐Cov‐2 antigen in Leydig cells, Sertoli cells, spermatogonia, and fibroblasts in all cases. EM detected viral particles in the cytoplasm of fibroblasts, endothelium, Sertoli and Leydig cells, spermatids, and epithelial cells of the rete testis in four cases, while RT‐PCR detected SARS‐CoV‐2 RNA in three cases. Discussion and conclusion The COVID‐19‐associated testicular lesion revealed a combination of orchitis, vascular changes, basal membrane thickening, Leydig and Sertoli cell scarcity, and reduced spermatogenesis associated with SARS‐CoV‐2 local infection that may impair hormonal function and fertility in men.

The ability of the new coronavirus SARS‐CoV‐2 to spread and contaminate is one of the determinants of the COVID‐19 pandemic status. SARS‐CoV‐2 has been detected in saliva consistently, with similar sensitivity to that observed in nasopharyngeal swabs. We conducted ultrasound‐guided postmortem biopsies in COVID‐19 fatal cases. Samples of salivary glands (SGs; parotid, submandibular, and minor) were obtained. We analyzed samples using RT‐qPCR, immunohistochemistry, electron microscopy, and histopathological analysis to identify SARS‐CoV‐2 and elucidate qualitative and quantitative viral profiles in salivary glands. The study included 13 female and 11 male patients, with a mean age of 53.12 years (range 8–83 years). RT‐qPCR for SARS‐CoV‐2 was positive in 30 SG samples from 18 patients (60% of total SG samples and 75% of all cases). Ultrastructural analyses showed spherical 70–100 nm viral particles, consistent in size and shape with the Coronaviridae family, in the ductal lining cell cytoplasm, acinar cells, and ductal lumen of SGs. There was also degeneration of organelles in infected cells and the presence of a cluster of nucleocapsids, which suggests viral replication in SG cells. Qualitative histopathological analysis showed morphologic alterations in the duct lining epithelium characterized by cytoplasmic and nuclear vacuolization, as well as nuclear pleomorphism. Acinar cells showed degenerative changes of the zymogen granules and enlarged nuclei. Ductal epithelium and serous acinar cells showed intense expression of ACE2 and TMPRSS receptors. An anti‐SARS‐CoV‐2 antibody was positive in 8 (53%) of the 15 tested cases in duct lining epithelial cells and acinar cells of major SGs. Only two minor salivary glands were positive for SARS‐CoV‐2 by immunohistochemistry. Salivary glands are a reservoir for SARS‐CoV‐2 and provide a pathophysiological background for studies that indicate the use of saliva as a diagnostic method for COVID‐19 and highlight this biological fluid's role in spreading the disease. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Context.— This study represents the largest compilation to date of clinical and postmortem data from decedents with coronavirus disease 2019 (COVID-19). It will augment previously published small series of autopsy case reports, refine clinicopathologic considerations, and improve the accuracy of future vital statistical reporting. Objective.— To accurately reflect the preexisting diseases and pathologic conditions of decedents with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection through autopsy. Design.— Comprehensive data from 135 autopsy evaluations of COVID-19–positive decedents is presented, including histologic assessment. Postmortem examinations were performed by 36 pathologists at 19 medical centers or forensic institutions in the United States and Brazil. Data from each autopsy were collected through the online submission of multiple-choice and open-ended survey responses. Results.— Patients dying of or with COVID-19 had an average of 8.89 pathologic conditions documented at autopsy, spanning a combination of prior chronic disease and acute conditions acquired during hospitalization. Virtually all decedents were cited as having more than 1 preexisting condition, encompassing an average of 2.88 such diseases each. Clinical conditions during terminal hospitalization were cited 395 times for the 135 autopsied decedents and predominantly encompassed acute failure of multiple organ systems and/or impaired coagulation. Myocarditis was rarely cited. Conclusions.— Cause-of-death statements in both autopsy reports and death certificates may not encompass the severity or spectrum of comorbid conditions in those dying of or with COVID-19. If supported by additional research, this finding may have implications for public health decisions and reporting moving forward through the pandemic.

Evidence regarding the impact of air pollution on acute respiratory distress syndrome (ARDS) is limited, and most studies focus on ARDS onset. Our study aimed to evaluate whether exposure to fine particulate matter interferes with lung recovery and remodeling in a murine model of acute lung injury. Forty-eight mice received nebulized LPS or the vehicle (controls). Blood, BALF, lungs and spleen were collected after 5 weeks of exposure to either PM2.5 (PM and LPS + PM group) or filtered air (control and LPS5w groups). Inflammatory cells and cytokines were assessed in the blood, BALF, lungs and spleen. Stereological analyses and remodeling assessments were performed by histology. The LPS + PM group showed increased BALF leukocytes, characterized by increased macrophages, increased IL-1β and IL-6 levels, anemia and thrombocytopenia. Moreover, we also observed septal thickening, decreased alveolar air space total volume and, septa surface density. Finally, regarding tissue remodeling, we observed elastosis of the lung parenchyma, and unlike in the LPS5w group, we did not observe fibrosis in the LPS + PM group. In conclusion, the delayed inflammation resolution due to subchronic exposure to PM2.5 could be influenced by low systemic and local lymphocyte counts, which lead to impaired lung injury recovery and tissue remodeling.

Background Pulmonary involvement in COVID-19 is characterized pathologically by diffuse alveolar damage (DAD) and thrombosis, leading to the clinical picture of Acute Respiratory Distress Syndrome. The direct action of SARS-CoV-2 in lung cells and the dysregulated immuno-coagulative pathways activated in ARDS influence pulmonary involvement in severe COVID, that might be modulated by disease duration and individual factors. In this study we assessed the proportions of different lung pathology patterns in severe COVID-19 patients along the disease evolution and individual characteristics. Methods We analysed lung tissue from 41 COVID-19 patients that died in the period March–June 2020 and were submitted to a minimally invasive autopsy. Eight pulmonary regions were sampled. Pulmonary pathologists analysed the H&E stained slides, performing semiquantitative scores on the following parameters: exudative, intermediate or advanced DAD, bronchopneumonia, alveolar haemorrhage, infarct (%), arteriolar (number) or capillary thrombosis (yes/no). Histopathological data were correlated with demographic-clinical variables and periods of symptoms-hospital stay. Results Patient´s age varied from 22 to 88 years (18f/23 m), with hospital admission varying from 0 to 40 days. All patients had different proportions of DAD in their biopsies. Ninety percent of the patients presented pulmonary microthrombosis. The proportion of exudative DAD was higher in the period 0–8 days of hospital admission till death, whereas advanced DAD was higher after 17 days of hospital admission. In the group of patients that died within eight days of hospital admission, elderly patients had less proportion of the exudative pattern and increased proportions of the intermediate patterns. Obese patients had lower proportion of advanced DAD pattern in their biopsies, and lower than patients with overweight. Clustering analysis showed that patterns of vascular lesions (microthrombosis, infarction) clustered together, but not the other patterns. The vascular pattern was not influenced by demographic or clinical parameters, including time of disease progression. Conclusion Patients with severe COVID-19 present different proportions of DAD patterns over time, with advanced DAD being more prevalent after 17 days, which seems to be influenced by age and weight. Vascular involvement is present in a large proportion of patients, occurs early in disease progression, and does not change over time.

Fine particulate matter (PM2.5) is a complex mixture of components with diverse chemical and physical characteristics associated with increased respiratory and cardiovascular diseases mortality. Our study aimed to investigate the effects of exposure to concentrated PM2.5 on LPS-induced lung injury onset. BALB/c male mice were exposed to either filtered air or ambient fine PM2.5 in an ambient particle concentrator for 5 weeks. Then, an acute lung injury was induced with nebulized LPS. The animals were euthanized 24 h after the nebulization to either LPS or saline. Inflammatory cells and cytokines (IL-1β, IL-4, IL-5, IL-6, IL-10, IL-17, TNF) were assessed in the blood, bronchoalveolar lavage fluid (BALF), and lung tissue. In addition, lung morphology was assessed by stereological methods. Our results showed that the PM+LPS group showed histological evidence of injury, leukocytosis with increased neutrophils and macrophages, and a mixed inflammatory response profile, with increased KC, IL-6, IL-1β, IL-4, and IL-17. Our analysis shows that there is an interaction between the LPS nebulization and PM2.5 exposure, differently modulating the inflammatory response, with a distinct response pattern as compared to LPS or PM2.5 exposure alone. Further studies are required to explain the mechanism of immune modulation caused by PM2.5 exposure.

The knowledge of COVID-19 pathophysiology is pivotal for the discovery of effective treatments. Here, we described that SARS-CoV-2 triggers the release of ACE2-depended neutrophil extracellular traps (NETs) that mediate lung pathology, supporting the use of NETs inhibitors for COVID-19 treatment., Severe COVID-19 patients develop acute respiratory distress syndrome that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that neutrophil extracellular traps (NETs) have been described as important mediators of tissue damage in inflammatory diseases, we investigated whether NETs would be involved in COVID-19 pathophysiology. A cohort of 32 hospitalized patients with a confirmed diagnosis of COVID-19 and healthy controls were enrolled. The concentration of NETs was augmented in plasma, tracheal aspirate, and lung autopsies tissues from COVID-19 patients, and their neutrophils released higher levels of NETs. Notably, we found that viable SARS-CoV-2 can directly induce the release of NETs by healthy neutrophils. Mechanistically, NETs triggered by SARS-CoV-2 depend on angiotensin-converting enzyme 2, serine protease, virus replication, and PAD-4. Finally, NETs released by SARS-CoV-2–activated neutrophils promote lung epithelial cell death in vitro. These results unravel a possible detrimental role of NETs in the pathophysiology of COVID-19. Therefore, the inhibition of NETs represents a potential therapeutic target for COVID-19., Graphical Abstract

Background Dengue infection is caused by an arbovirus with a wide range of presentations, varying from asymptomatic disease to unspecific febrile illness and haemorrhagic syndrome with shock, which can evolve to death. In Brazil, the virus circulates since the 1980s with many introductions of new serotypes, genotypes, and lineages since then. Here we report a fatal case of dengue associated with a Dengue virus (DENV) lineage not detected in the country until now. Case presentation The patient, a 58-year-old man arrived at the hospital complaining of fever and severe abdominal pain due to intense gallbladder edema, mimicking acute abdomen. After 48 h of hospital admission, he evolved to refractory shock and death. DENV RNA was detected in all tissues collected (heart, lung, brain, kidney, spleen, pancreas, liver, and testis). Viral sequencing has shown that the virus belongs to serotype 2, American/Asian genotype, in a new clade, which has never been identified in Brazil before. The virus was phylogenetically related to isolates from central America [Puerto Rico (2005–2007), Martinique (2005), and Guadeloupe (2006)], most likely arriving in Brazil from Puerto Rico. Conclusion In summary, this was the first fatal documented case with systemic dengue infection associated with the new introduction of Dengue type 2 virus in Brazil during the 2019 outbreak.

Background Patients with asthma present structural and inflammatory alterations that are believed to play a role in disease severity. However, airway remodeling and inflammation have not been extensively investigated in relation to both symptom control and airflow obstruction in severe asthmatics. We aimed to investigate several inflammatory and structural pathological features in bronchial biopsies of severe asthmatics that could be related to symptom control and airflow obstruction after standardized treatment. Methods Fifty severe asthmatics received prednisone 40 mg/d for 2 weeks and maintenance therapy with budesonide/formoterol 400/12 μg twice daily + budesonide/formoterol 200/6 μg as needed for 12 weeks. Endobronchial biopsies were performed at the end of 12 weeks. We performed extensive immunopathological analyses of airway tissue inflammation and remodeling features in patients stratified by asthma symptom control and by airflow obstruction. Results Airway tissue inflammation and remodeling were not associated with symptom control. Asthmatics with persistent airflow obstruction had greater airway smooth muscle (Asm) area with decreased periostin and transforming growth factor beta-positive cells within Asm bundles, in addition to lower numbers of chymase-positive mast cells in the submucosa compared to patients with nonpersistent obstruction. Conclusions Symptom control in severe asthmatics was not associated with airway tissue inflammation and remodeling, although persistent airflow obstruction in these patients was associated with bronchial inflammation and airway structural changes.

Background Diffuse alveolar damage (DAD), which is the histological surrogate for acute respiratory distress syndrome (ARDS), has a multifactorial aetiology. Therefore it is possible that the immunopathology differs among the various presentations of DAD. The aim of this study is to compare lung immunopathology of viral (influenza A(H1N1)pdm09) to non-viral, extrapulmonary aetiologies in autopsy cases with DAD. Methods The lung tissue of 44 patients, was divided in the H1N1 group (n = 15) characterized by severe pulmonary injury due to influenza A(H1N1)pdm09 infection; the ARDS group (n = 13), characterized by patients with DAD due to non-pulmonary causes; and the Control group (n = 16), consisting of patients with non-pulmonary causes of death. Immunohistochemistry and image analysis were used to quantify, in the parenchyma and small airways, several immune cell markers. Results Both DAD groups had higher expression of neutrophils and macrophages in parenchyma and small airways. However, there was a higher expression of CD4+ and CD8+ T lymphocytes, CD83+ dendritic cells, granzyme A+ and natural killer + cell density in the lung parenchyma of the H1N1 group (p

Background Gastro-esophageal reflux disease (GERD) and broncho-aspiration (BA) are known to increase the risk for chronic lung allograft dysfunction (CLAD). However, specific lung injury mechanisms are not clearly known. The objective of the study was to describe histopathological findings in surveillance lung transbronchial biopsies that can be correlated with episodes of BA in the lung allograft. Methods This retrospective analysis of surveillance transbronchial biopsies was performed in lung transplant recipients, with available data of broncho-alveolar fluid (cultures and cytology), lung function parameters, and esophageal functional tests. Results Were analyzed 11 patients, divided into 3 groups: (1) GERD group: 4 patients with GERD and CLAD diagnosis; (2) control group: 2 patients without GERD or CLAD; and (3) BA group: 5 patients with foreign material in lung biopsies. A histopathological pattern of neutrophilic bronchitis (NB) was present in 4 of 4 cases in the GERD group and in 1 of 5 cases in the BA group in 2 or more biopsy samples; culture samples were all negative; the 5 NB-positive patients developed CLAD and died (3/5) or needed re-transplantation (2/5). The other 3 patients in the BA group had GERD without NB or CLAD. Both patients in the control group had transient NB in biopsies with positive cultures but remained free of CLAD. Conclusions Surveillance transbronchial biopsies may provide useful information other than the evaluation of acute cellular rejection and can help to identify high-risk patients for allograft dysfunction related to gastro-esophageal reflux.

Background New strategies for collecting post-mortem tissue are necessary, particularly in areas with emerging infections. Minimally invasive autopsy (MIA) has been proposed as an alternative to conventional autopsy (CA), with promising results. Previous studies using MIA addressed the cause of death in adults and children in developing countries. However, none of these studies was conducted in areas with an undergoing infectious disease epidemic. We have recently experienced an epidemic of yellow fever (YF) in Brazil. Aiming to provide new information on low-cost post-mortem techniques that could be applied in regions at risk for infectious outbreaks, we tested the efficacy of ultrasound-guided MIA (MIA-US) in the diagnosis of patients who died during the epidemic. Methodology/principal findings In this observational study, we performed MIA-US in 20 patients with suspected or confirmed YF and compared the results with those obtained in subsequent CAs. Ultrasound-guided biopsies were used for tissue sampling of liver, kidneys, lungs, spleen, and heart. Liver samples from MIA-US and CA were submitted for RT-PCR and immunohistochemistry for detection of YF virus antigen. Of the 20 patients, 17 had YF diagnosis confirmed after autopsy by histopathological and molecular analysis. There was 100% agreement between MIA-US and CA in determining the cause of death (panlobular hepatitis with hepatic failure) and main disease (yellow fever). Further, MIA-US obtained samples with good quality for molecular studies and for the assessment of the systemic involvement of the disease. Main extrahepatic findings were pulmonary hemorrhage, pneumonia, acute tubular necrosis, and glomerulonephritis. One patient was a 24-year-old, 27-week pregnant woman; MIA-US assessed the placenta and provided adequate placental tissue for analysis. Conclusions MIA-US is a reliable tool for rapid post-mortem diagnosis of yellow fever and can be used as an alternative to conventional autopsy in regions at risk for hemorrhagic fever outbreaks with limited resources to perform complete diagnostic autopsy., Author summary Reliable mortality information is of paramount importance to establish sound public health policies. Autopsy is an important tool not only for determining the cause of death, but also for the detection of novel diseases. In the last decades, we have been globally identifying an unprecedented number of emerging infections. Therefore, there is great interest in the development of less invasive and low-cost tools for the accurate post-mortem diagnosis in fatal cases. Minimally invasive autopsy (MIA), conceived as targeting diagnostic biopsies of key organs by needle puncture, has been proposed as an alternative to conventional autopsy (CA) for the determination of cause of death in developing countries. In this research, we tested the efficacy of MIA in the post-mortem diagnosis of 20 patients with suspected or confirmed yellow fever who died during the recent epidemic of yellow fever that occurred in Brazil. There was a perfect agreement between MIA and CA in determining the cause of death (hepatic failure) and main disease (yellow fever) in all patients with confirmed yellow fever. This finding indicates that MIA can be used as an alternative to CA in regions at risk for infectious disease outbreaks with limited resources to perform conventional autopsies.

Introduction/Objective Tracheal resection with primary reconstruction is the definitive treatment for many tracheal benign and malignant diseases. When primary resection is not deemed feasible as a result of the length of the stenosis, airway transplantation may become a solution. Tissue engineering offers an alternative way for creating tracheal substitutes. The development of tracheal allograft transplantation includes the decellularized tracheal scaffolds made of extracellular matrix that are seeded with the receptor's cells. Many protocols are used to obtain a decellularized scaffold. Most of them consist of cyclical physical-chemical steps with enzymes. This study proposes a protocol for decellularization based only in physical-chemical steps. Methods Decellularization of pig tracheal segments was carried out using a standardized protocol consisting of freezing and thawing, 10 cycles of agitation, exposure to sodium deoxycholate, and washing. The degree of decellularization was determined by quantifying residual DNA. We also analyzed the morphology under hematoxylin and eosin staining. Results Fourteen porcine tracheal segments were decellularized. All scaffolds obtained showed less than 2% of residual DNA (mean 20 ± 8 ng/mg) when compared to the fresh samples (mean 850 ± 123 ng/mg), P = .001. Morphological analysis showed that the epithelium and mixed glands were completely removed. It was possible to identify residual nuclei inside the cartilaginous rings (73.7 ± 12 × 26 ± 8 nuclei/field, P Conclusion The protocol tested was able to provide effective decellularization of porcine tracheas.

Aims The clinical spectrum of yellow fever (YF) ranges from asymptomatic to fulminant hepatitis. During the sylvatic YF epidemic in the metropolitan area of Sao Paulo, Brazil in 2018, seven orthotopic liver transplantations (OLTs) were performed in our institution to treat fulminant YF hepatitis. Three patients recovered, while four patients died following OLT. The autopsy findings of all these cases are presented herein as the first description of YF in transplanted patients. Methods and results All patients were men, aged 16-40 years, without vaccination to YF virus (YFV). All organs were examined, with tissue sampling for histopathological analysis. Detection of YF virus antigens (YFV Ag) was performed with two primary antibodies (mouse polyclonal anti-YFV antibody directed to wild strain and a goat anti-YF virus antibody), and RT-PCR assays were utilised to detect YFV-RNA. All the cases depicted typical findings of YF hepatitis in the engrafted liver. The main extrahepatic findings were cerebral oedema, pulmonary haemorrhage, pneumonia, acute tubular necrosis and ischaemic/reperfusion pancreatitis. Of the four cases, the YVF Ag was detected in the heart in one case, liver and testis in three cases, and the kidney and spleen in all four cases. All four cases had YF virus RNA detected by RT-PCR in the liver and in other organs. Conclusions Infection of the engrafted liver and other organs by YFV, possibly combined with major ischaemic systemic lesions, may have led to the death of four of the seven patients undergoing OLT.

Background Mortality related to asthma has decreased worldwide since the introduction of inhaled corticosteroid therapy in the past decades. However, there are still some asthma fatalities identified mainly in populations with less access to regular treatment. Pulmonary interstitial emphysema due to alveolar rupture has been rarely described as a complication of an acute severe asthma attack, and its identification in pathological analysis can be difficult. Previous studies reported the association of pulmonary interstitial emphysema and bronchial ductal gland ectasia in asthma. Case presentation We present the case of a 42-year- old man that died due to a fatal asthma attack. Postmortem computed tomography revealed the unusual finding of acute Pulmonary Interstitial Emphysema, confirmed by pathological analysis. We reviewed 28 cases of fatal asthma tissue and identified the presence of pulmonary interstitial emphysema in 10% of the cases. Conclusions Postmortem computed tomography is a useful complimentary diagnostic tool for autopsies. Pulmonary Interstitial Emphysema in acute exacerbations of asthma seems to be more frequent than reported. Alveolar hyperdistension and bronchial duct gland ectasia causing tissue rupture are possible mechanisms involved in the formation of Pulmonary Interstitial Emphysema. The clinical impact of Pulmonary Interstitial Emphysema in asthma is unknown.

Air pollution is a growing problem worldwide, inducing and exacerbating several diseases. Among the several components of air pollutants, particulate matter (PM), especially thick (10–2.5 µm; PM 10) and thin (≤2.5 µm; PM 2.5), are breathable particles that easily can be deposited within the lungs, resulting in pulmonary and systemic inflammation. Although physical activity is strongly recommended, its effects when practiced in polluted environments are questionable. Therefore, the present study evaluated the pulmonary and systemic response of concomitant treadmill training with PM 2.5 and PM 10 exposure. Treadmill training inhibited PM 2.5- and PM 10-induced accumulation of total leukocytes (p

This case illustrates a rare presentation (as lymphadenopathy and fever) of one of the most common zoonotic diseases worldwide-brucellosis-in a 22-year-old Brazilian male (a chef) who had recently returned to Brazil after having lived in and traveled around Europe for one year. The histopathology, clinical history, and response to treatment were all consistent with a diagnosis of brucellosis, which was confirmed by PCR in a urine sample. We also review some aspects of brucellosis, such as the clinical features, diagnosis, and management.

The cardiac chamber's involvement with neoplastic embolism has been rarely reported; it is mostly associated with gastric, breast, lung, liver, and prostate cancers, and usually affects the pulmonary arteries. This paper reports a case of a 31-year-old man with a malignant testicular germ cell tumor who presented with multiple episodes of pulmonary thromboembolism and died of sudden respiratory failure 1 year after the initial diagnosis. Death was attributed to massive pulmonary embolism and pulmonary infarction associated with a neoplastic thrombus that extended from the gonadal veins to pulmonary arteries. A postmortem computerized tomographic angiography and autopsy confirmed this finding.

Background and objective Acute respiratory distress syndrome (ARDS) has a high mortality rate of 35–46% depending on its severity. Animal models are crucial to better understand the pathophysiology of diseases, including ARDS. This study presents a feasible animal model of acute lung injury (ALI) using nebulized lipopolysaccharide (LPS) in a non-invasive approach, focusing on its short and long-term effects. Methods Mice received nebulized LPS or vehicle only (control group). Blood, BALF and lung tissue were collected 24 hours (LPS 24h) or 5 weeks (LPS 5w) after the nebulized LPS-induced lung injury. Inflammatory cytokines were assessed in the blood serum, BALF and lung tissue. Stereological analyses and remodeling changes were assessed by histology and immunohistochemistry at the specified time points. Results The LPS 24h group showed increased pro-inflammatory cytokine levels, intense cell influx, increased total septal volume, septal thickening and decreased surface density of the alveolar septa. The LPS 5w group showed persistent lung inflammation, septal thickening, increased total lung volume, accentuated collagen deposition, especially of collagen type I, and decreased MMP-2 protein expression. Conclusion We present a feasible, reproducible and non-invasive nebulized-LPS animal model that allows the assessment of both the acute and late phases of acute lung injury. The presence of lung remodeling with collagen deposition after 5 weeks makes it useful to study the pathophysiology, complications, and possible therapeutic intervention studies that aim to understand and reduce pulmonary fibrosis in the late phases of ALI.

The prevalence of marijuana use among pregnant women is high. However, the effects on gestation and fetal development are not well known. Epidemiological and experimental studies present conflicting results because of the route of administration, dose, time of exposure, species used, and how Cannabis toxicity is tested (prepared extracts, specific components, or by pyrolysis). In this study, we experimentally investigated the effects of maternal inhalation of Cannabis sativa smoke representing as nearly as possible real world conditions of human marijuana use. Pregnant mice (n=20) were exposed (nose-only) daily for 5min to marijuana smoke (0.2g of Cannabis) from gestational day (GD) 5.5 to GD17.5 or filtered air. Food intake and maternal weight gain were recorded. Ultrasound biomicroscopy was performed on 10.5 and 16.5dpc.On GD18.5, half of the dams were euthanized for the evaluation of term fetus, placenta, and resorptions. Gestation length, parturition, and neonatal outcomes were evaluated in the other half. Five minutes of daily (low dose) exposure during pregnancy resulted in reduced birthweight, and litter size was not altered; however, the number of male pups per litter was higher. Besides, placental wet weight was increased and fetal to placental weight ratio was decreased in male fetuses, showing a sex-specific effect. At the end of gestation, females from the Cannabis group presented reduced maternal net body weight gain, despite a slight increase in their daily food intake compared to the control group. In conclusion, our results indicate that smoking marijuana during pregnancy even at low doses can be embryotoxic and fetotoxic.

Summary Objectives Pulmonary hypertension is a lethal complication of chronic hepatosplenic schistosomiasis. Little is known of the underlying (immuno-)histopathological characteristics of lung vasculopathy. Methods We characterized vasculopathy and inflammation in lung tissue of 10 patients with Schistosomiasis -associated PH (SCH-PH) in comparison to 22 idiopathic pulmonary arterial hypertension (IPAH) patients and 10 normal controls. SCH-PH cases were younger than controls. Results Plexiform lesions and/or angiomatoid lesions were found in 10/10 SCH-PH, and 19/22 IPAH patients ( χ 2 p = 0.22). Lung granulomas with Schistosoma eggs were found in 2/10 of SCH-PH cases. PAH cases had increased peri-arterial density of CD3+ T cells, chymase+ and tryptase+ mast cells when compared to controls ( p ≤ 0.047). SCH-PH showed increased density of CD4+ cells when compared to controls ( p = 0.025), paralleled by an increased density of dendritic CD83+ cells when compared to both controls and IPAH patients ( p ≤ 0.022). Conclusion Both SCH-PH and IPAH feature plexogenic arteriopathy and increased periarterial T cell and mast cell density. SCH-PH and IPAH differ only with respect to the density of dendritic CD83+ cells. These findings imply ongoing antigenic stimulation in SCH-PH, yet a pattern of pulmonary vasculopathy similar to IPAH, suggestive of a final common pathway in their pathogenesis of PAH.

Introduction Aquaporins and ion channels are membrane proteins that facilitate the rapid movement of water and solutes across biological membranes. Experimental and in vitro studies reported that the function of these channels and pulmonary edema resolution are impaired in acute lung injury (ALI). Although current evidence indicates that alveolar fluid clearance is impaired in patients with ALI/diffuse alveolar damage (DAD), few human studies have addressed the alterations in pulmonary channels in this clinical condition. Additionally, it is not known whether the primary cause of DAD is a relevant variable for the channel dysfunction. Methods Autopsied lungs of 43 patients with acute respiratory failure (ARF) due to DAD of three different etiologies, non-pulmonary sepsis, H1N1 viral infection and leptospirosis, were compared to 18 normal lungs. We quantified the expression of aquaporin (AQP) 1, AQP3, AQP5, epithelial Na+ channel (ENaC) and sodium potassium ATPase (Na-K-ATPase) in the alveolar septum using immunohistochemistry and image analysis. Results The DAD group presented with increased expression of AQP3, AQP5 and Na-K-ATPase and decreased expression of ENaC compared to controls. However, there was no difference in protein expression within the DAD groups of different etiologies. Conclusion Water and ion channels are altered in patients with ARF due to DAD. The cause of DAD does not seem to influence the level of impairment of these channels.

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a chronic fibrosing interstitial pneumonia, which involves aberrant serotonin (5-hydroxytryptamine [5-HT]) and Akt signaling. As protective effects of chronic aerobic training (AT) have been demonstrated in the context of lung injury, this study investigated whether AT attenuates bleomycin-induced lung fibrosis partly via a reduction of 5-HT and AKT signaling. METHODS: Seventy-two C57BL/6 male mice were distributed in Control (Co), Exercise (Ex), Fibrosis (Fi), and Fibrosis + Exercise (Fi + Ex) groups. Bleomycin (1.5 UI·kg) was administered on day 1 and treadmill AT began on day 15 and continued for 60 min·d, 5 d·wk for 4 wk. We evaluated total and differential cell counts in bronchoalveolar lavage (BAL), interleukin (IL)-1β, IL-6, CXCL1/KC, IL-10, tumor necrosis factor α, and transforming growth factor β levels in BAL, collagen content in lung parenchyma, 5-HT levels in BAL fluid and in serum, the expression of 5-HT2B receptor, and Akt phosphorylation in lung tissue. RESULTS: AT reduced bleomycin-increased number of total cells (P < 0.001), neutrophils (P < 0.01), macrophages (P < 0.01), and lymphocytes (P < 0.05) in BAL. It also reduced the levels of IL-1β (P < 0.01), IL-6 (P < 0.05), CXCL1/KC (P < 0.001), tumor necrosis factor α (P < 0.001), and transforming growth factor β (P < 0.001). It increased expression of ant-inflammatory cytokine IL-10 (P < 0.001). It reduced bleomycin-increased 5-HT levels in BAL (P < 0.001) and in serum (P < 0.05). Reductions in collagen fiber deposition (P < 0.01), 5-HT2B receptor expression (P < 0.01), and Akt phosphorylation in lung tissue were observed. CONCLUSIONS: AT accelerates the resolution of lung inflammation and fibrosis in a model of bleomycin-induced lung fibrosis partly via attenuation of 5-HT/Akt signaling. &nbsp

Aerobic conditioning (AC) performed either during or after sensitization reduces allergic inflammation in mice; however, the effects of AC performed before and during allergic sensitization on airway inflammation are unknown. Mice were divided into Control, AC, OVA, and AC + OVA groups. Mice were trained in a treadmill followed by either ovalbumin (OVA) sensitization or saline administration. Peribronchial inflammation, OVA-specific IgE and IgG1 titers, the expression of Th1 and Th2 cytokines, and airway remodeling were evaluated, as well as the expression of Eotaxin, RANTES, ICAM-1, VCAM-1, TGF-β and VEGF. Aerobic conditioning performed before and during allergic sensitization displayed an inhibitory effect on the OVA-induced migration of eosinophils and lymphocytes to the airways, a reduction of IgE and IgG1 titers and an inhibition of the expression of Th2 cytokines. The AC + OVA group also demonstrated reduced expression of ICAM-1, VCAM-1, RANTES, TGF-β and VEGF, as well as decreased airway remodeling (p

We evaluated the effects of cigarette smoke (CS) on lung inflammation and remodeling in a model of ovalbumin (OVA)-sensitized and OVA-challenged mice. Male BALB/c mice were divided into 4 groups: non-sensitized and air-exposed (control); non-sensitized and exposed to cigarette smoke (CS), sensitized and air-exposed (OVA) (50μg+OVA 1% 3 times/week for 3 weeks) and sensitized and cigarette smoke exposed mice (OVA+CS). IgE levels were not affected by CS exposure. The increases in total bronchoalveolar fluid cells in the OVA group were attenuated by co-exposure to CS, as were the changes in IL-4, IL-5, and eotaxin levels as well as tissue elastance (p

Airway epithelium plays an important role in the asthma physiopathology. Aerobic exercise decreases Th2 response in murine models of allergic asthma, but its effects on the structure and activation of airway epithelium in asthma are unknown. BALB/c mice were divided into control, aerobic exercise, ovalbumin-sensitized and ovalbumin-sensitized plus aerobic exercise groups. Ovalbumin sensitization occurred on days 0, 14, 28, 42, and aerosol challenge from day 21 to day 50. Aerobic exercise started on day 22 and ended on day 50. Total cells and eosinophils were reduced in ovalbumin-sensitized group submitted to aerobic exercise. Aerobic exercise also reduced the oxidative and nitrosative stress and the epithelial expression of Th2 cytokines, chemokines, adhesion molecules, growth factors and NF-kB and P2X7 receptor. Additionally, aerobic exercise increased the epithelial expression of IL-10 in non-sensitized and sensitized animals. These findings contribute to the understanding of the beneficial effects of aerobic exercise for chronic allergic airway inflammation, suggesting an immune-regulatory role of exercise on airway epithelium.

Background: Up to 60% of chronic obstructive pulmonary disease (COPD) patients can present airway hyperresponsiveness. However, it is not known whether the peripheral lung tissue also shows an exaggerated response to agonists in COPD. Objectives: To investigate the in vitro mechanical behavior and the structural and inflammatory changes of peripheral lung tissue in COPD patients and compare to nonsmoking controls. Methods: We measured resistance and elastance at baseline and after acetylcholine (ACh) challenge of lung strips obtained from 10 COPD patients and 10 control subjects. We also assessed the alveolar tissue density of neutrophils, eosinophils, macrophages, mast cells and CD8+ and CD4+ cells, as well as the content of α-smooth muscle actin-positive cells and elastic and collagen fibers. We further investigated whether changes in in vitro parenchymal mechanics correlated to structural and inflammatory parameters and to in vivo pulmonary function. Results: Values of resistance after ACh treatment and the percent increase in tissue resistance (%R) were higher in the COPD group (p ≤ 0.03). There was a higher density of macrophages and CD8+ cells (p < 0.05) and a lower elastic content (p = 0.003) in the COPD group. We observed a positive correlation between %R and eosinophil and CD8+ cell density (r = 0.608, p = 0.002, and r = 0.581, p = 0.001, respectively) and a negative correlation between %R and the ratio of forced expiratory volume in 1 s to forced vital capacity (r = –0.451, p < 0.05). Conclusions: The cholinergic responsiveness of parenchymal lung strips is increased in COPD patients and seems to be related to alveolar tissue eosinophilic and CD8 lymphocytic inflammation and to the degree of airway obstruction on the pulmonary function test.

Airway epithelium plays important roles in the pathophysiology of asthma. Creatine supplementation (Cr) was shown to increase asthma features in a murine model of allergic asthma; however, the role of the airway epithelium in this inflammatory response is not known. BALB/c mice were divided into control, creatine supplementation, ovalbumin-sensitized (OVA) and OVA plus creatine supplementation groups. OVA sensitization occurred on days 0, 14, 28 and 42, and ovalbumin challenge from days 21-53. Cr was also given on days 21-53. Total and differential cells counts in BALF were evaluated. Quantitative epithelial expression of interleukin (IL)-4, IL-5, IL-13, CCL11, CCL5, CCL2, iNOS, VCAM-1, ICAM-1, NF-κB, VEGF, TGF-β, IGF-1, EGFR, TIMP-1, TIMP-2, MMP-9, MMP-12 and arginase II were performed. Cr increased the number of total cells and eosinophils in BALF, the epithelial content of goblet cells and the epithelial expression of IL-5, CCL2, iNOS, ICAM-1, NF-κB, TGF-β, TIMP-1 and MMP-9 when compared to the control group (p

To evaluate the effects of different mechanical ventilation (MV) strategies on the mucociliary system.Experimental study.Twenty-seven male New Zealand rabbits.After anesthesia, animals were tracheotomized and ventilated with standard ventilation [tidal volume (Vt) 8 ml/kg, positive end expiratory pressure (PEEP) 5 cmH(2)O, flow 3 L/min, FiO(2) 0.4] for 30 min. Next, animals were randomized into three groups and ventilated for 3 h with low volume (LV): Vt 8 ml/kg, PEEP 5 cmH(2)O, flow 3 L/min (n = 6); high volume (HV): Vt 16 ml/kg, PEEP 5 cmH(2)O, flow 5 L/min (n = 7); or high pressure (HP): Ppeak 30 cmH(2)O, PEEP 12 cmH(2)O (n = 8). Six animals (controls) were ventilated for 10 min with standard ventilation. Vital signals, blood lactate, and respiratory system mechanics were verified. Tracheal tissue was collected before and after MV.Lung and tracheal tissue sections were stained to analyze inflammation and mucosubstances by the point-counting method. Electron microscopy verified tracheal cell ultrastructure. In situ tracheal ciliary beating frequency (CBF), determined using a videoscopic technique, and tracheal mucociliary transport (TMCT), assessed by stereoscopic microscope, were evaluated before and after MV.Respiratory compliance decreased in the HP group. The HV and HP groups showed higher lactate levels after MV. Macroscopy showed areas of atelectasis and congestion on HV and HP lungs. Lung inflammatory infiltrate increased in all ventilated groups. Compared to the control, ventilated animals also showed a reduction of total and acid mucus on tracheal epithelium. Under electron microscopy, injury was observed in the ciliated cells of the HP group. CBF decreased significantly after MV only in the HP group. TMCT did not change significantly in the ventilated groups.Different MV strategies induce not only distal lung alterations but also morphological and physiological tracheal alterations leading to mucociliary system dysfunction.

We evaluated if repeated stress modulates mucociliary clearance and inflammatory responses in airways of guinea pigs (GP) with chronic inflammation. The GP received seven exposures of ovalbumin or saline 0.9%. After 4th inhalation, animals were submitted to repeated forced swim stressor protocol (5×/week/2 weeks). After 7th inhalation, GP were anesthetized. We measured transepithelial potential difference, ciliary beat frequency, mucociliary transport, contact angle, cough transportability and serum cortisol levels. Lungs and adrenals were removed, weighed and analyzed by morphometry. Ovalbumin-exposed animals submitted to repeated stress had a reduction in mucociliary transport, and an increase on serum cortisol, adrenals weight, mucus wettability and adhesivity, positive acid mucus area and IL-4 positive cells in airway compared to non-stressed ovalbumin-exposed animals (p < 0.05). There were no effects on eosinophilic recruitment and IL-13 positive cells. Repeated stress reduces mucociliary clearance due to mucus rheological-property alterations, increasing acid mucus and its wettability and adhesivity. These effects seem to be associated with IL-4 activation. © 2010 Elsevier B.V. All rights reserved.

Background: Aerobic exercise decreases pulmonary inflammation and remodeling in experimental models of allergic asthma. However, the effects of aerobic exercise on pulmonary inflammation of nonallergic origin, such as in experimental models of acute lung injury induced by lipopolysaccharide (LPS), have not been evaluated. Objective: The present study evaluated the effects of aerobic exercise in a model of LPS-induced acute lung injury. Methods: BALB/c mice were divided into four groups: Control, Aerobic Exercise, LPS, and Aerobic Exercise + LPS. Swimming tests were conducted at baseline and at 3 and 6 wk. Low-intensity swimming training was performed for 6 wk, four times per week, 60 min per session. Intranasal LPS (1 mg[middle dot]kg-1 (60 [mu]g per mouse)) was instilled 24 h after the last swimming physical test in the LPS and Aerobic Exercise + LPS mice, and the animals were studied 24 h after LPS instillation. Exhaled nitric oxide, respiratory mechanics, total and differential cell counts in bronchoalveolar lavage, and lung parenchymal inflammation and remodeling were evaluated. Results: LPS instillation resulted in increased levels of exhaled nitric oxide (P < 0.001), higher numbers of neutrophils in the bronchoalveolar lavage (P < 0.001) and in the lung parenchyma (P < 0.001), and decreased lung tissue resistance (P < 0.05) and volume proportion of elastic fibers (P < 0.01) compared with the Control group. Swim training in LPS-instilled animals resulted in significantly lower exhaled nitric oxide levels (P < 0.001) and fewer neutrophils in the bronchoalveolar lavage (P < 0.001) and the lung parenchyma (P < 0.01) compared with the LPS group. Conclusions: These results suggest that low-intensity swimming training inhibits lung neutrophilic inflammation, but not remodeling and impaired lung mechanics, in a model of LPS-induced acute lung injury.

We recently demonstrated that creatine supplementation increased some features of lung allergic sensitization in mice. On the other hand, other studies have shown that aerobic exercise inhibited allergic airway inflammation and remodeling. We hypothesized that aerobic exercise may decrease the exacerbatory effects of the creatine supplementation in a murine model of asthma. Balb/c mice were divided into six groups: Control, Creatine (Cr), Low Intensity Exercise+Creatine (Low+Cr), Ovalbumin (OVA), Ovalbumin+Creatine (OVA+Cr) and Ovalbumin+Creatine+Low Intensity Exercise (OVA+Cr+Low). OVA-sensitized groups were sensitized with OVA intraperitoneal injections (days 0, 14, 28, and 42). Aerosol challenge (OVA 1%) and Cr treatment (0.5 g/kg/day) were initiated on Day 21 until Day 53. Low intensity exercise began on day 22 and was sustained until day 50. Low intensity exercise in the presence of creatine supplementation in sensitized mice resulted in a decreased number of eosinophils in BALF (p

We evaluated the influence of iNOS-derived NO on the mechanics, inflammatory, and remodeling process in peripheral lung parenchyma of guinea pigs with chronic pulmonary allergic inflammation. Animals treated or not with 1400 W were submitted to seven exposures of ovalbumin in increasing doses. Seventy-two hours after the 7th inhalation, lung strips were suspended in a Krebs organ bath, and tissue resistance and elastance measured at baseline and after ovalbumin challenge. The strips were submitted to histopathological measurements. The ovalbumin-exposed animals showed increased maximal responses of resistance and elastance (p0.05), eosinophils counting (p0.001), iNOS-positive cells (p0.001), collagen and elastic fiber deposition (p0.05), actin density (p0.05) and 8-iso-PGF2alpha expression (p0.001) in alveolar septa compared to saline-exposed ones. Ovalbumin-exposed animals treated with 1400 W had a significant reduction in lung functional and histopathological findings (p0.05). We showed that iNOS-specific inhibition attenuates lung parenchyma constriction, inflammation, and remodeling, suggesting NO-participation in the modulation of the oxidative stress pathway.

The perimeter of the basement membrane (Pbm) of an airway viewed in cross section is used as a marker of airway size because in normal lungs it is relatively constant, despite variations in airway smooth muscle (ASM) shortening and airway collapse. In vitro studies (McParland BE, Pare PD, Johnson PR, Armour CL, Black JL. J Appl Physiol 97: 556-563, 2004; Noble PB, Sharma A, McFawn PK, Mitchell HW. J Appl Physiol 99: 2061-2066, 2005) have suggested that differential stretch of the Pbm between asthmatic and nonasthmatic airways fixed in inflation may occur and lead to an overestimation of ASM thickness in asthma. The relationships between the Pbm and the area of ASM were compared in transverse sections of airways from cases of fatal asthma (F) and from nonasthmatic control (C) cases where the lung tissue had been fixed inflated (Fi; Ci) or uninflated (Fu; Cu). When all available airways were used, the regression slopes were increased in Fu and Cu, compared with Fi and Ci, and increased in Fu and Fi, compared with Cu and Ci, suggesting effects of both inflation and asthma group, respectively. When analyses were limited to airway sizes that were available for all groups (Pbm < 15 mm), the slopes of Fi and Fu were similar, but both were greater than Ci and Cu, which were also similar. It was calculated that the effect of asthma group accounted for 80% and inflation for 20% of the differences between Fi and Ci. We conclude that the effects of inflation on the relationship between Pbm and ASM are small and do not account for the differences observed in ASM between cases of asthma and nonasthmatic controls.

VIEIRA, R. P., R. F. FRANCA, N. R. DAMACENO-RODRIGUES, M. DOLHNIKOFF, E. G. CALDINI, C. R. CARVALHO, and W. RIBEIRO. Dose-Dependent Hepatic Response to Subchronic Administration of Nandrolone Decanoate. Med. Sci. Sports Exerc., Vol. 40, No. 5, pp. 842–847, 2008. Background: Androgenic anabolic steroids (AAS) are synthetic hormone derivatives of testosterone and are mainly used to enhance athletic performance and muscle mass, but medical applications also have been described. Short- and longterm side effects have been demonstrated in many organs, but the liver adverse effects are the most common and serious ones associated with AAS use. However, these effects have been supported by few clinical and experimental studies. Objective: To evaluate the hepatic function and structure after 5 wk of nandrolone decanoate administration at three different doses. Methods: Twenty-seven adult male Wistar rats were randomly assigned to the following groups: control, clinical, intermediate, and suprapharmacological doses of nandrolone decanoate during 5 wk. Results: The biochemical studies showed that nandrolone decanoate administration leads to a dosedependent increase in serum levels of the aspartate aminotransferase (AST) (P G 0.05), alanine aminotransferase (ALT) (P G 0.01), and alkaline phosphatase (ALP) (P G 0.001), as well as a significant decrease in total proteins (P G 0.01), bilirubin (P G 0.05), total cholesterol and fractions (P G 0.05), and triglycerides (P G 0.05). Although a significant statistical difference was found for AST, ALT, and ALP when compared with the control group, their values remained within the normal range. The number of Kupffer cells was increased in the liver parenchyma (P G 0.05), and the content of collagen was increased in the central lobular vein wall, in the hepatic parenchyma, and in the portal space (P G 0.05). Conclusions: These results suggest that subchronic treatment with nandrolone decanoate, mainly administered at higher-than-clinical doses, are potentially deleterious to the liver, leading to incipient fibrosis.

Creatine supplement is the most popular nutritional supplement, and has various metabolic functions and sports medicine applications. Creatine supplementation increases muscle mass and can decrease muscular inflammation. Some studies have also suggested a beneficial role of creatine supplementation on chronic pulmonary diseases such as chronic obstructive pulmonary disease and cystic fibrosis. Among athletes, the prevalence of asthma is high, and many of these individuals may be taking creatine. However, the effects of creatine supplementation on chronic pulmonary diseases of allergic origin have not been investigated. In the present study, we analyzed the effects of creatine supplementation on a model of chronic allergic lung inflammation. Thirty-one Balb/c mice were divided into four groups: control, creatine (Cr), ovalbumin (OVA), and OVA+Cr. OVA and OVA+Cr groups were sensitized with intraperitoneal injections of OVA on Days 0, 14, 28, and 42. OVA challenge (OVA 1%) and Cr treatment (0.5 g/kg/d) were initiated on Day 21 and lasted until Day 53. We determined the index of hyperresponsiveness, the serum levels of OVA-specific immunoglobulin (Ig)E and IgG(1), and the total and differential cell counts in bronchoalveolar lavage fluid. We also quantified airway inflammation, and the airway density of IL-4+, IL-5+, IL-2+, IFN-gamma+, and insulin-like growth factor (IGF)-1+ cells, collagen and elastic fibers, and airway smooth muscle thickness. Our results showed that creatine in OVA-sensitized mice increased hyperresponsiveness; eosinophilic inflammation; airway density of IL-4+, IL-5+, and IGF-1 inflammatory cells; airway collagen and elastin content; and smooth muscle thickness. The results show that creatine supplementation exacerbates the lung allergic response to OVA through a T helper cell type 2 pathway and increased IGF-1 expression.

Aerobic conditioning improves exercise capacity and decreases symptoms in patients with asthma. However, its benefits in the context of allergic airway inflammation are poorly understood.To evaluate the effects of two intensities of aerobic exercise on airway inflammation and remodeling in a model of chronic allergic lung inflammation.Mice were subjected to chronic ovalbumin (OVA) sensitization and to 4 weeks of low (OVA+Low) or moderate (OVA+Mod) exercise training in a treadmill. Airway inflammation and remodeling and expression of helper T-cell type 1 and 2 cytokines were evaluated.OVA-induced allergic airway inflammation and remodeling were characterized by an increase in collagen (288%), elastic fiber (56%), smooth muscle (380%), and epithelial (402%) contents (P0.001) when compared with the control group. OVA+Low and OVA+Mod groups presented a decrease in bronchoalveolar lavage fluid eosinophils (respectively, 84 and 75%; P0.01) and airway walls (respectively, 94 and 58%; P0.001) when compared with the OVA group. OVA+Low and OVA+Mod groups also presented a reduction in the number of peribronchial inflammatory cells expressing IL-4 (respectively, 85 and 75%; P0.01) and IL-5 (respectively, 88 and 89%; P0.01) when compared with the OVA group. Aerobic conditioning did not change the expression of either IFN-gamma or IL-2 by inflammatory cells or plasma levels of IgE or IgG1. OVA+Low and OVA+Mod groups presented an increase in the expression of IL-10 (P0.001). Low and moderate aerobic conditioning also reduced airway remodeling in OVA-sensitized mice when compared with the OVA group.We concluded that low and moderate aerobic exercise decreases airway inflammation and remodeling in a murine model of asthma.

Our purpose in this study was to access the pulmonary effects of mechanical ventilation with positive end-expiratory pressure (PEEP; 10 cmH2O) or without PEEP (zero PEEP-ZEEP) in a rat model of acute myocardial infarction that resulted in hypotension but not in pulmonary congestion.Wistar rats were anesthetized (1.5% isoflurane) and myocardial infarct was induced by ligature of the anterior interventricular coronary artery. Rats with myocardial infarct were compared with sham-operated (Sham) and closed thorax groups.There was a significant decrease in MAP in the acute myocardial infarct group (92.5 +/- 4.2 mmHg) when compared with closed chest group (113.0 +/- 4.4 mmHg). There was no significant difference between acute myocardial infarct and Sham groups in PEEP or ZEEP. Mechanical ventilation for 120 min resulted in a significant increase in respiratory system elastance in the groups ventilated with ZEEP (2.59 +/- 0.17 and 2.32 +/- 0.17 cmH2O.mL, Sham and acute myocardial infarct groups, respectively). This effect of mechanical ventilation was not observed in the presence of PEEP in both groups. There was no significant increase in the amount of perivascular pulmonary edema measured in all groups studied. Mean airspace linear intercept and lung tissue distortion index also did not show statistically significant difference between Sham and acute myocardial infarct groups. We conclude that in this experimental model of acute myocardial infarct (12.4 +/- 4.1% area of necrotic tissue and 26.4 +/- 4.0% area of ischemic tissue), there was a protective pulmonary effect of PEEP.

The nose is the first region of the respiratory tract to come in contact with airborne pollutants. Previous studies have shown that the nasal mucosa can be altered in response to air pollution. In this study, we quantified neutral and acidic mucus in three different levels of the nasal cavity of mice exposed to ambient levels of air pollution in the city of São Paulo, Brazil. Two groups of 6-day-old male Swiss mice were placed in two exposure chambers. Mice were maintained in the chambers 24 h/day, 7 days/week for 5 months. The first chamber contained an air filter device (clean chamber; n=20), whereas the second one received ambient air pollution (polluted chamber; n=20). We measured the concentration of PM(2.5), nitrogen dioxide (NO2), and black carbon inside both chambers. The nasal cavity was transversely sectioned at three specific anatomic locations (proximal, medial, and distal levels) and submitted to quantitative analysis of the amounts of neutral and acidic mucosubstances. We observed a 37.85% decrease in NO2, 54.77% decrease in PM(2.5), and 100% decrease in black carbon concentration in the clean chamber compared to the polluted chamber. Significant differences between polluted and clean chambers were observed in the epithelium lining the septum of proximal and medial levels of the nasal mucosa, with an increase in the percentage of acidic mucus in the polluted chamber (P=0.037, proximal level; P=0.023, medial level). We conclude that prolonged exposure to low levels of ambient air pollution from an early age shows evidence of causing secretory changes in the nasal cavity of mice, with increased production of acidic mucosubstances.

The peripheral lung parenchyma has been studied as a component of the asthmatic inflammatory response. During induced constriction, tissue resistance increases in different asthma models. Approximately 60% of the asthmatic patients show early and late responses. The late response is characterized by more severe airway obstruction. In the present study, we evaluated lung parenchymal strips mechanics in ovalbumin-sensitized guinea pigs, trying to reproduce both early and late inflammatory responses. Oscillatory mechanics of lung strips were performed in a control group (C), in an early response group (ER), and in two late response groups: 17 h (L1) and 72 h (L2) after the last ovalbumin challenge. Measurements of resistance and elastance were obtained before and after ovalbumin challenge in C and ER groups and before and after acetylcholine challenge in all groups. Using morphometry, we assessed the density of eosinophils and smooth muscle cells, as well as collagen and elastin content in lung strips. The baseline and postagonist values of resistance and elastance were increased in ER, L1, and L2 groups compared with C ( P ≤ 0.001). The morphometric analysis showed an increase in alveolar eosinophil density in ER and L2 groups compared with C ( P < 0.05). There was a significant correlation between eosinophil density in parenchymal strips of C, L1, and L2 groups and values of resistance and elastance postacetylcholine ( r = 0.71, P = 0.001 and r = 0.74, P < 0.001, respectively). The results show that the lung parenchyma is involved in the late response, and the constriction response in this phase is related to the eosinophilic inflammation.

Epidemiological studies have shown that air pollution increases cardiovascular morbidity and mortality. Objective markers of cardiovascular risk have also been associated with increases in ambient pollution. This study was designed to assess whether prolonged exposure to ambient levels of air pollution may induce structural alterations of pulmonary and cardiac vessels. Mice were chronically exposed to ambient levels of air pollution in downtown São Paulo, Brazil. The animals were maintained in exposure chambers, 24 h/day, 7 days/wk, during 4 mo. One group was exposed to ambient air, and the control group was exposed to filtered air. Morphometric measurements of the ratio between the lumen and wall (L/W) areas were performed on transverse sections of renal, pulmonary, and coronary arteries. As expected, lumen/wall ratios increased with arterial caliber (p.001). A significant decrease of L/W with exposure to air pollution was detected in pulmonary (p = .03) and coronary (p = .021) arteries, whereas no effects of air pollution were observed in renal vessels. Our results indicate that animals chronically exposed to ambient air pollution develop a significant thickening of the arterial wall in the coronary and pulmonary circulation.

Background The mechanisms leading to death from asthma are not completely understood. Recent studies suggest the involvement of the anaphylatoxins C3a and C5a, generated during complement activation, and their receptors C3aR and C5aR in the pathogenesis of asthma. Objective The aim of our study was to investigate the expression of C3aR and C5aR in fatal asthma. Methods We analyzed lung tissue from 14 subjects who died of asthma (fatal asthma; FA) and 14 subjects who died of nonpulmonary causes (controls) and bronchial biopsy specimens from 16 subjects with mild intermittent asthma (MIA). C3aR and C5aR expression was evaluated by immunohistochemistry, and a semiquantitative analysis of the intensity of staining was performed according to a visual analogue scale (score, 0-3). Results C3aR was expressed on airway epithelium, smooth muscle, submucosal, and parenchymal vessels. C5aR was expressed on myeloid cells infiltrating the submucosa and on airway epithelium. Statistical analysis demonstrated higher expression of C3aR on submucosal vessels in FA compared with controls and MIA (median [minimum-maximum], controls, 0.24 [0-1.48]; MIA, 0.0 [0-1.00]; FA, 1.56 [0.13-3]; P =.002). C3aR was also increased on parenchymal vessels in FA (controls, 0.56 [0-2.00]; FA, 1.81 [0.5-3]; P =.0004). C5aR expression on airway epithelium was increased in FA compared with controls and MIA (controls, 1.25 [0.25-3]; MIA, 1.00 [0-2.00]; FA, 3.00 [1.13-3.00]; P =.001). Conclusion The results of our study suggest a role of complement in FA.

Summary Background The site and distribution of inflammation in the airways of asthmatic patients has been largely investigated. Inflammatory cells are distributed in both large and small airways in asthma. It has been demonstrated that distal lung inflammation in asthma may significantly contribute to the pathophysiology of the disease. The upper airways have also been implicated in the overall asthmatic inflammation. Although it is now accepted that lung inflammation is not restricted to the intrapulmonary airways in asthma, little is known about cell distribution in the other lung compartments and their relation to the intrapulmonary airways. Objective We aimed to map the inflammatory process in fatal asthma (FA), from the upper airways to the lung parenchyma. Methods Eosinophil, neutrophil, mast cell and lymphocyte content were determined in nasal mucosa, the trachea, intrapulmonary airways and parenchyma (peribronchiolar and distal) of 20 patients with FA and 10 controls. Results Eosinophil content was higher in all studied areas in FA compared with controls (Po0.02). Mast cell content was higher in the outer area of larger airways, small membranous bronchioles and in peribronchiolar parenchyma of FA compared with controls (Po0.04). CD3 1 , CD4 1 and CD20 1 cells showed increased content in FA intrapulmonary airways compared with controls (Po0.05). There was a positive correlation between CD4 1 cell content in nasal mucosa and larger airways in asthmatics. Increased neutrophil content was observed only in peribronchiolar parenchyma of FA (P 5 0.028). Conclusion Eosinophils present a widespread distribution within the respiratory tract in FA, from the nasal mucosa to the distal lung. The outer wall of small membranous bronchioles is the main site of inflammatory changes in FA. There is a localized distribution of alveolar inflammation at the peribronchiolar region for mast cells and neutrophils. Our findings provide further evidence of the importance of the lung periphery in the pathophysiology of FA.

The mechanisms involved in the association between air pollution and increased cardiovascular morbidity are not fully understood. The objective of this study was to test the hypothesis that fine particulate matter (PM(2.5)) induces systemic inflammation and vasoconstriction of small arteries in the lung and heart of rats. Thirty-eight healthy Wistar rats were anesthetized, intubated, and submitted to the instillation of 1 ml of distilled water diluted in the following solution: blank filter, 100 microg and 500 microg of PM(2.5). PM(2.5) was collected in glass fiber filters with a high-volume sampler. The animals were sacrificed 24 h after instillation when blood, heart, and lung samples were collected for morphological and wet-to-dry weight ratio analysis. PM(2.5) consisted of the following elements: sulphur, arsenic, bromine, chlorine, cobalt, iron, lanthanum, manganese, antimony, scandium, and thorium. Total reticulocytes significantly increased at both PM(2.5) doses (p0.05) while hematocrit levels increased in the 500 microg group (p0.05). Quantification of segmented neutrophils and fibrinogen levels showed a significant decrease, while lymphocytes counting increased with 100 microg of PM(2.5) (p0.05). A significant dose-dependent decrease of intra-acinar pulmonary arteriole lumen/wall ratio (L/W) was observed in PM groups (p0.001). Peribronchiolar arterioles L/W showed a significant decrease in the 500 microg group (p0.001). A significant increase in heart wet-to-dry weight ratio was observed in the 500 microg group (p0.001). In conclusion, fine environment particles in the city of São Paulo promote pulmonary and cardiac histological alterations. Pulmonary vasculature was markedly affected by particle instillation, resulting in significant vasoconstriction in healthy rats.

Small airway disease is thought to contribute significantly to functional impairment caused by asthma. Functional evidence of airway-parenchyma uncoupling in asthma, such as loss of deep breath bronchodilator effect in bronchoconstrictive episodes and enhanced airway closure, has been previously demonstrated. Elastic fibers are essential to maintain adequate elastic recoil of the lungs. In this study, we hypothesized that alveolar attachments could be abnormal and that elastic fibers could be damaged in the distal lungs of patients with fatal asthma. For this purpose, we measured the number of abnormal alveolar attachments and quantified the content of elastic fibers in the adventitial layer of small airways and in the peribronchial and distal alveolar septa of 15 patients who died of asthma (FA) and 9 control subjects (CTRL). Our data (geometric mean [range]) showed an increased proportion of abnormal alveolar attachments per centimeter of basement membrane perimeter in fatal asthma (FA, 0.18 [0.03-4.00]; CTRL, 0.00 [0.00-0.12]; p0.001) and decreased elastic fiber content in the small airway adventitial layer (FA, 4.08 [2.22-11.46] microm; CTRL, 6.79 [5.62-10.0] microm; p = 0.01) and in the peribronchial alveoli (FA, 1.08 [0.46-1.91] microm; CTRL, 1.81 [1.22-1.74] microm; p = 0.003), but not in the distal alveoli. We propose that structural alterations at the peribronchiolar level might contribute to the pathogenesis of some functional abnormalities observed in patients with severe asthma.

Carotid bodies are chemoreceptors sensitive to a fall of partial oxygen pressure in blood (hypoxia). The morphological alterations of these organs in patients with chronic obstructive pulmonary disease (COPD) and in people living at high altitude are well known. However, it is not known whether the histological profile of human carotid bodies is changed in acute clinical conditions such as acute respiratory distress syndrome (ARDS). The objective of the present study was to perform a quantitative analysis of the histology of carotid bodies collected from patients who died of ARDS. A morphometric study of carotid bodies collected during routine autopsies was carried out on three groups: patients that died of non-respiratory diseases (controls, N = 8), patients that presented COPD and died of its complications or associated diseases (N = 7), and patients that died of ARDS (N = 7). Morphometric measurements of the volume fraction of clusters of chief cells were performed in five fields on each slide at 40X magnification. The numerical proportion of the four main histological cell types (light, dark, progenitor and sustentacular cells) was determined analyzing 10 fields on each slide at 400X magnification. The proportion of dark cells was 0.22 in ARDS patients, 0.12 in controls (P

The association between asthma and gastroesophageal reflux has been attributed to microaspiration of gastric contents and/or vagally mediated reflex bronchoconstriction. In previous experimental studies concerning the pulmonary effects of tracheal or esophageal acid infusion, only animals without airway inflammation have been studied. We assessed the effects of esophageal and tracheal administration of hydrochloric acid (HCl) on normal guinea pigs (GP) and GP with airway inflammation induced by repeated ovalbumin exposures. These GP were anesthetized (pentobarbital sodium) and received 1) 20 μl of either 0.2 N HCl or saline into the trachea, or 2) 1 ml of either 1 N HCl or saline into the esophagus. Intratracheal HCl resulted in a significant increase in both respiratory system elastance and resistance ( P < 0.001). There were no significant changes in respiratory mechanics when HCl was infused into the esophagus. In conclusion, we observed that infusion of large volumes of HCl into the esophagus did not change pulmonary mechanics significantly, even in guinea pigs with chronic allergen-induced airway inflammation. In contrast, intratracheal administration of small amounts of acid had substantial effects in normal GP and GP with airway inflammation.

Creatine (Cr) is a dietary supplement that presents beneficial effects in experimental models of heart and brain ischemia and reperfusion (I/R) injury. It can improve adenosine 5'-triphosphate generation and reduce cell damage. This study evaluated the effects of Cr supplementation in a model of lung I/R.Forty male Wistar rats were divided into 4 groups: sham operated, Cr+sham, I/R, and Cr+I/R. We investigated the effects of 5 days of Cr supplementation (0.5 g/kg/day by gavage) before left pulmonary artery ischemia (90 minutes) and reperfusion (120 minutes) on pulmonary and systemic response.Cr inhibited the I/R-induced increase in exhaled nitric oxide (p0.05), total cells (p0.01), and neutrophils (p0.001) in bronchoalveolar lavage fluid and in the systemic circulation (p0.001). The levels of interleukin-1β (p0.05), tissue damping, and tissue elastance (p0.05) were also minimized. Cr also inhibited pulmonary edema formation (total proteins in bronchoalveolar lavage fluid, p0.001; histologic edema index, p0.001) and neutrophils accumulation in lung tissue (p0.001). As possible mechanisms underlying Cr effects, we observed a reduced expression of caspase 3 (p0.05), reduced expression of Toll-like receptor (TLR) 4, and increased expression of TLR7 in lung tissue (p0.001).Cr supplementation presents pulmonary and systemic protective effects in acute lung injury induced by I/R in rats. These beneficial effects seem to be related to the anti-inflammatory and anti-oxidant properties of Cr and modulation of TLRs.

Background Immune responses in asthmatic patients involve coordinated cellular responses in the airways and lymph nodes (LNs). However, no studies have described the composition of different cell populations in the bronchopulmonary LNs of asthmatic patients. Objective We sought to investigate the expression of dendritic cells (DCs) and costimulatory molecules, B cells, T cells, T H 2-related cytokines, eosinophils, and vascular cell adhesion molecule in the bronchopulmonary LNs and large airways of asthmatic patients. Methods Using histochemistry, immunohistochemistry, and image analysis, we investigated the expression of Factor XIIIa + , CD1a + , CD83 + , and CD207 + DCs; CD4 + and CD8 + T cells; CD20 + B cells; CD23 + (FceRII) cells; IL-4; IL-5; eosinophils, and vascular cell adhesion molecule 1 in the large airways and bronchopulmonary LNs of 11 nonsmokers who died from an asthma exacerbation (fatal asthma [FA]) in comparison with 8 nonasthmatic control subjects. In selected cases of FA, we analyzed the coexpression of HLA-DR, CD40, and CD80 in lung and LN eosinophils. Results The LNs of asthmatic patients exhibited increased density of eosinophils. No other cells were expressed differently in the LNs of patients with FA. The large airways of patients with FA had increased expression of eosinophils in all layers and increased expression of Factor XIIIa + cells, CD4 + and CD8 + T cells, CD20 + B cells, and CD23 + cells in the outer layer. There was colocalization of HLA-DR, CD40, and CD80 in the eosinophils at both sites. Conclusions FA is associated with the increased presence of eosinophils in the LNs and large airways, which express HLA-DR and costimulatory molecules. The expression of Factor XIIIa + monocyte-derived DCs, CD4 + and CD8 + T cells, CD20 + B cells, and CD23 + cells was increased in the large airways without a corresponding increase in the expression of these cells in the bronchopulmonary LNs. These findings support the concept that eosinophils might act as antigen-presenting cells in patients with FA.