Rationale: Pseudomonas aeruginosa is the major bacterial pathogen colonizing the airways of adult patients with cystic fibrosis (CF) and causes chronic infections that persist despite antibiotic therapy. Intracellular bacteria may represent an unrecognized reservoir of bacteria that evade the immune system and antibiotic therapy. Although the ability of P. aeruginosa to invade and survive within epithelial cells has been described in vitro in different epithelial cell models, evidence of this intracellular lifestyle in human lung tissues is currently lacking. Objectives: To detect and characterize intracellular P. aeruginosa in CF airway epithelium from human lung explant tissues. Methods: We sampled lung explant tissues from patients with CF undergoing lung transplantation and non-CF lung donor control tissue. We analyzed lung tissue sections for the presence of intracellular P. aeruginosa using quantitative culture and microscopy, in parallel to histopathology and airway morphometry. Measurements and Main Results: P. aeruginosa was isolated from the lungs of seven patients with CF undergoing lung transplantation. Microscopic assessment revealed the presence of intracellular P. aeruginosa within airway epithelial cells in three of the seven patients analyzed at a varying but low frequency. We observed those events occurring in lung regions with high bacterial burden. Conclusions: This is the first study describing the presence of intracellular P. aeruginosa in CF lung tissues. Although intracellular P. aeruginosa in airway epithelial cells is likely relatively rare, our findings highlight the plausible occurrence of this intracellular bacterial reservoir in chronic CF infections.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, immune dysregulation, and multi-organ fibrosis. Interstitial lung disease (ILD) is a complication of SSc and a leading cause of SSc-death. The administration of hypochlorous acid (HOCl) intradermally in the mouse (HOCl-SSc) purportedly shows several features typical of SSc. We studied the model by injecting BALB/c mice daily intradermally with HOCl for 6-weeks, an exposure reported to induce lung fibrosis. On day 42, the skinfold thickness and the dermal thickness were two and three times larger respectively in the HOCl group compared to controls. HOCl treatment did not result in histological features of pulmonary fibrosis nor significant changes in lung compliance. Automated image analysis of HOCl mice lungs stained with picrosirius red did not show increased collagen deposition. HOCl injections did not increase pulmonary mRNA expression of pro-fibrotic genes nor induced the production of serum advanced oxidation protein products and anti-topoisomerase 1 antibodies. Immune cells in bronchoalveolar lavage fluid (BALF) and whole lung digests were not increased in HOCl-treated animals. Since lung fibrosis is proposed to be triggered by oxidative stress, we injected HOCl to Nrf2-/- mice, a mouse deficient in many antioxidant proteins. Lung compliance, histology, and BALF leukocyte numbers were comparable between Nrf2-/- mice and wild-type controls. We conclude that the HOCl-SSc model does not manifest SSc-lung disease.

Of all 428 resectable stage II and III NSCLC patients included in this study, 25% received neoadjuvant therapy. Perioperative outcomes and 5-year overall survival were similar between patients having received neoadjuvant therapy versus upfront surgery. Establishing a neoadjuvant therapy program for NSCLC is feasible and safe from a surgical perspective. Background: Several regulatory agencies have approved the use of the neoadjuvant chemo-immunotherapy for resectable stage II and III of non -small cell lung cancer (NSCLC) and numerous trials investigating novel agents are underway. However, significant concerns exist around the feasibility and safety of offering curative surgery to patients treated within such pathways. The goal in this study was to evaluate the impact of a transition towards a large-scale neoadjuvant therapy program for NSCLC. Methods: Medical charts of patients with clinical stage II and III NSCLC who underwent resection from January 2015 to December 2020 were reviewed. The primary outcome was perioperative complication rate between neoadjuvant-treated versus upfront surgery patients. Multivariable logistic regression estimated occurrence of postoperative complications and overall survival was assessed as an explorator y secondar y outcome by Kaplan-Meier and Cox -regression analyses. Results: Of the 428 patients included, 106 (24.8%) received neoadjuvant therapy and 322 (75.2%) upfront surgery. Frequency of minor and major postoperative complications was similar between groups ( P = .22). Occurrence in postoperative complication was similar in both cohort (aOR = 1.31, 95% CI 0.73-2.34). Neoadjuvant therapy administration increased from 10% to 45% with a rise in targeted and immuno therapies over time, accompanied by a reduced rate of preoperative radiation therapy use. 1-, 2-, and 5 -year overall survival was higher in neoadjuvant therapy compared to upfront surgery patients (Log -Rank P = .017). Conclusions: No significant differences in perioperative outcomes and survival were observed in resectable NSCLC patients treated by neoadjuvant therapy versus upfront surgery. Transition to neoadjuvant therapy among resectable NSCLC patients is safe and feasible from a surgical perspective.

Aspergillus fumigatus airway infections are associated with increased rates of hospitalizations and declining lung function in patients with chronic lung disease. While the pathogenesis of invasive A. fumigatus infections is well studied, little is known about the development and progression of airway infections. Previous studies have demonstrated a critical role for the IL-1 cytokines, IL-1α and IL-1β in enhancing pulmonary neutrophil recruitment during invasive aspergillosis. Here we use a mouse model of A. fumigatus airway infection to study the role of these IL-1 cytokines in immunocompetent mice. In the absence of IL-1 receptor signaling, mice exhibited reduced numbers of viable pulmonary neutrophils and increased levels of neutrophil apoptosis during fungal airway infection. Impaired neutrophil viability in these mice was associated with reduced pulmonary and systemic levels of G-CSF, and treatment with G-CSF restored both neutrophil viability and resistance to A. fumigatus airway infection. Taken together, these data demonstrate that IL-1 dependent G-CSF production plays a key role for host resistance to A. fumigatus airway infection through suppressing neutrophil apoptosis at the site of infection.

•Distinguishing between MPLC and IPM is critical in lung oncology.•A probabilistic model determined joint probability of mutations identified in 2 tumors.•NGS results were most useful in cases of concordant mutations with low mutation frequency.Our series identified high incidence of KRAS and low incidence of EGFR mutations.•Accuracy of diagnosis can be significantly improved with integration of NGS data.

Background Pneumocystis jirovecii pneumonia (PJP) can be challenging to diagnose, often requiring bronchoscopy. Since most patients suspected of PJP undergo imaging, we hypothesized that the findings of these studies could help estimate the probability of disease prior to invasive testing. Methods We created a cohort of patients who underwent bronchoscopy specifically to diagnose PJP and conducted a nested case-control study to compare the radiographic features between patients with ( n = 72) and without ( n = 288) pathologically proven PJP. We used multivariable logistic regression to identify radiographic features independently associated with PJP. Results Chest x-ray findings poorly predicted the diagnosis of PJP. However, multivariable analysis of CT scan findings found that “increased interstitial markings” (OR 4.3; 95%CI 2.2–8.2), “ground glass opacities” (OR 3.3; 95%CI 1.2–9.1) and the radiologist’s impression of PJP being “possible” (OR 2.0; 95%CI 1.0–4.1) or “likely” (OR 9.3; 95%CI 3.4–25.3) were independently associated with the final diagnosis (c-statistic 0.75). Conclusions Where there is clinical suspicion of PJP, the use of CT scan can help determine the probability of PJP. Identifying patients at low risk of PJP may enable better use of non-invasive testing to avoid bronchoscopy while higher probability patients could be prioritized.

Venous air embolism (VAE) is a rare cause of death for which special procedures are needed for autopsy diagnosis. The current one of choice was devised by Richter in 1905 to prevent introduction of gas into the right heart while opening the thorax. We could find no published data demonstrating that that this occurs during standard autopsy technique. Two scenarios were investigated. In the first, the study group included cases using the traditional method to open the thoracic cage; in the control group, Richter’s method was used. Gas was collected under water and measured in a calibrated tube. The second scenario involved cases in which an intracardiac catheter was present at autopsy. In these, 50 mL of air was injected prior to chest opening and the amount of intracardiac air was measured. The first (non-injected) study and control groups consisted of 28 and 26 cases, respectively. Gas was identified in 3 cases (10%) in the study group and 2 cases (7%) in the control group. In the ten injected cases, there was a significant difference in the amount of the gas recovered (10 mL in the standard cases and 30 mL in the Richter group). No significant artifactual gas entrapment occurs in the right heart using the standard autopsy technique. However, it is possible that this technique may cause loss of intracardiac gas and if there is a clinical suspicion of VAE, Richter’s technique should be used.

24 Airway colonization by the mold Aspergillus fumigatus is common in patients with underlying 25 lung disease and is associated with chronic airway inflammation. Studies probing the 26 inflammatory response to colonization with A. fumigatus hyphae have been hampered by the lack 27 of a model of chronic colonization in immunocompetent mice. By infecting mice intratracheally 28 with conidia embedded in agar beads (Af beads), we have established an in vivo model to study 29 the natural history of airway colonization with live A. fumigatus hyphae. Histopathological 30 examination and galactomannan assay of lung homogenates demonstrated that hyphae exited 31 beads and persisted in the lungs of mice up to 28 days post-infection without invasive disease. 32 Fungal lesions within the airways were surrounded by a robust neutrophilic inflammatory 33 reaction and peribronchial infiltration of lymphocytes. Whole lung cytokine analysis from Af 34 bead-infected mice revealed an increase in pro-inflammatory cytokines and chemokines early in 35 infection. Evidence of a Th2 type response was observed only early in the course of 36 colonization, including increased levels of IL-4, elevated serum IgE levels and a mild increase in 37 airway responsiveness. Pulmonary T cell subset analysis during infection mirrored these results 38 with an initial transient increase in IL-4 producing CD4 T cells, followed by a rise in IL-17 and 39 Foxp3 cells by day 14. These results provide the first report of the evolution of the immune 40 response to A. fumigatus hyphal colonization. 41

Airway colonization by the mold Aspergillus fumigatus is common in patients with underlying lung disease and is associated with chronic airway inflammation. Studies probing the inflammatory response to colonization with A. fumigatus hyphae have been hampered by the lack of a model of chronic colonization in immunocompetent mice. By infecting mice intratracheally with conidia embedded in agar beads (Af beads), we have established an in vivo model to study the natural history of airway colonization with live A. fumigatus hyphae. Histopathological examination and galactomannan assay of lung homogenates demonstrated that hyphae exited beads and persisted in the lungs of mice up to 28 days postinfection without invasive disease. Fungal lesions within the airways were surrounded by a robust neutrophilic inflammatory reaction and peribronchial infiltration of lymphocytes. Whole-lung cytokine analysis from Af bead-infected mice revealed an increase in proinflammatory cytokines and chemokines early in infection. Evidence of a Th2 type response was observed only early in the course of colonization, including increased levels of interleukin-4 (IL-4), elevated IgE levels in serum, and a mild increase in airway responsiveness. Pulmonary T cell subset analysis during infection mirrored these results with an initial transient increase in IL-4-producing CD4(+) T cells, followed by a rise in IL-17 and Foxp3(+) cells by day 14. These results provide the first report of the evolution of the immune response to A. fumigatus hyphal colonization.

The response of the vascular endothelium to wall shear stress plays a central role in the development and progression of atherosclerosis. Current studies have investigated endothelial response using idealized in vitro flow chambers. Such cell culture models are unable to accurately replicate the complex in vivo wall shear stress patterns arising from anatomical geometries. To better understand this implication, we have created both simplified/tubular and anatomically realistic in vitro endothelial flow models of the human right coronary artery. A post-mortem vascular cast of the human left ventricular outflow tract was used to create geometrically accurate silicone elastomer models. Straight, tubular models were created using a custom made mold. Following the culture of human abdominal aortic endothelial cells within the inner lumen, cells were exposed to steady flow (Re = 233) for varying time periods. The resulting cell morphology was analyzed in terms of shape index and angle of orientation relative to the flow direction. In both models a progressive elongation and alignment of the endothelium in the flow direction was observed following 8, 12, and 24 hours. This change, however, was significantly less pronounced in the anatomical model (as observed from morphological variations indicative of localized flow features). Differences were also observed between the inner and outer walls at the disease-prone proximal region. Since morphological adaptation is a visual indication of endothelial shear stress activation, the use of anatomical models in endothelial genetic and biochemical studies may offer better insight into the disease process.

Surgical treatment of active infective valvular endocarditis is associated with substantial morbidity and mortality, particularly when the infection spreads below the primary infected valve. We report the case of a patient in whom acute mitral regurgitation (MR) developed secondary to the rupture of both papillary muscles (PMs) after aortic valve replacement (AVR) for infective endocarditis. A previously healthy 23-year-old morbidly obese man was transferred to our hospital with a 5-day history of left-sided chest pain, dyspnea, cough, and fever. On arrival, his blood pressure was 120/48 mm Hg, with a regular pulse rate of 148 beats/min, a temperature of 38.6°C, a respiratory rate of 26 breaths/min, and an oxygen saturation of 86% on room air. The only remarkable physical findings were a grade III/VI long, diastolic, blowing murmur at the right second interspace and a progressively decreasing level of consciousness, with no focal neurologic signs. After intubation, a transesophageal echocardiogram revealed the presence of a 1 × 3-cm vegetation involving the right and left aortic leaflets and associated with severe aortic insufficiency with an ejection fraction of 30%. There was no evidence of abscess, and the anterior mitral leaflet was intact with minimal MR. The patient was taken to the operating room for an emergency AVR. Under cardiopulmonary bypass, an aortotomy was performed and the aortic valve (AV) was excised. A 2-cm aortic abscess involving the ventricular septum was identified. After thorough debridement of all the infected tissue, reconstruction of the aortic annulus was achieved using bovine pericardium followed by insertion of a number 21 St Jude mechanical valve (St Jude Medical Inc, St Paul, Minn). Postoperatively, the patient's condition gradually improved. However, on postoperative day 4, the patient's fever spiked to, his white count increased to 37.5, his systolic pressure decreased to 70 mm Hg, and his wedge pressure increased to 28 mm Hg. Shortly thereafter, cardiac arrest occurred and the patient died after attempted resuscitation for more than 30 minutes. Examination of the heart at autopsy revealed a competent AV with no vegetation or thrombus. However, both the anterior and posterior PMs were ruptured and the posteroseptal myocardium contained a 2.5 × 1.5-cm abscess (Figure 1). Histologic examination showed myocardial necrosis and marked acute inflammation of both papillary heads, consistent with septic embolization of the small coronary branches supplying these muscles. Gram-positive cocci, consistent with Group B streptococcus found in blood cultures, were identified in the necrotic tissue. Additional foci of septic embolization were seen in the kidneys and spleen. Aortic root infection occurs in one third of all patients with native valve endocarditis and is associated with substantial morbidity and mortality.1Siniawski H. Grauhan O. Hofmann M. et al.Aortic root abscess and secondary infective mitral valve disease: results of surgical endocarditis treatment.Eur J Cardiothorac Surg. 2005; 27: 434-440Crossref PubMed Scopus (29) Google Scholar The major determinants for the successful surgical management of these cases are the complete exclusion and thorough debridement of the infected cavities.2David T.E. Bos J. Christakis G.T. Brofman P.R. Wong D. Feindel C.M. Heart valve operations in patients with active infective endocarditis.Ann Thorac Surg. 1990; 49: 701-713Abstract Full Text PDF PubMed Scopus (95) Google Scholar MR in the setting of AV endocarditis is a potential complication but has not been described as occurring secondary to bilateral PM rupture. The clinical presentation of PM rupture is closely linked to the blood supply of the anterolateral and posteromedial PMs. Because of its single blood supply, the posteromedial PM is most frequently involved. Both muscles, however, are vulnerable to ischemic insult resulting from embolic occlusion or hypoperfusion of the terminal intramyocardial arterial branches. Our patient's course is similar to that of 2 other cases of PM rupture caused by coronary embolism in patients who underwent AVR for endocarditis.3Jinno T. Tago M. Yamane M. Nakagawa J. Ishiai S. A case of infective endocarditis with subtotal rupture of the posterior papillary muscle.Kyobu Geka. 1995; 48: 487-490PubMed Google Scholar, 4Edwards J. Mitral insufficiency resulting from “overshooting” of leaflets.Circulation. 1971; 43: 606-612Crossref PubMed Scopus (23) Google Scholar The main difference is that our patient had rupture of both PMs, explaining the postoperative deterioration of the patient's condition. There is only 1 previously reported fatal case of rupture of both PMs in the setting of acute myocardial infarction.5Patel A.D. Abo-Auda W. Chowdhury N. et al.Rupture of both papillary muscles after acute myocardial infarction: a case report.Heart Dis. 2002; 4: 285-287Crossref PubMed Scopus (2) Google Scholar The exact mechanism of bilateral PM rupture in our patient is difficult to explain and could not be defined by echocardiography because of the sudden onset of cardiac arrest. However, the autopsy findings and temporal evolution of MR suggest that its cause is most likely a combination of an occult infection of the PM and an ischemic insult caused by small-vessel embolism from AV endocarditis. Infective endocarditis of the AV may be complicated by a subvalvular abscess involving the intervalvular fibrosa, a coronary embolism, or the rupture of one PM. Each of these complications has been described individually, but the rate at which they occur simultaneously is low, especially when both PMs are affected, and survival in such a case is unlikely. Nevertheless, a high index of suspicion allowing early recognition and prompt surgical intervention is the only hope to try to salvage this rare complication of bacterial endocarditis.

A posterior mediastinal mass was found incidentally in a 70-year-old woman during a work-up for an early breast cancer. Computed tomography of the chest showed a well-circumscribed mass near the left subclavian artery and proximal descending aorta. A left video assisted thorascopic excision of the posterior mediastinal mass was performed. Pathologic examination showed it to be a chondromatous hamartoma, representing a very unusual location for this type of tumor.

A case of recurrent acute fludarabine pulmonary toxicity in a 67-year-old man with non-Hodgkin’s lymphoma is presented. The patient responded well to high dose steroid therapy. The literature with respect to this rare entity is reviewed.

We examined the effects of 10 min of lower lateral chest wall percussion with a mechanical percussor or hand clapping in groups of anesthetized, paralyzed, and ventilated supine dogs. Mechanical percussion was applied at 10–16 Hz and caused an esophageal pressure swing (delta Pes) of 10–17 cmH2O. Hand clapping was applied at 4–7 Hz and caused a delta Pes of 6–17 cmH2O. At necropsy there were large reddened areas on the lateral surface of the underlying lung as well as smaller reddened areas on the hilar surfaces of both lungs and on the lateral surface of the opposite lung. These reddened regions were demonstrated to be atelectatic by postmortem lung inflation (which caused the reddened areas to disappear) and by microscopic examination. Despite the atelectasis, gas exchange improved toward the end of the percussion or clapping period. In four dogs that were ventilated for an additional 20 min after percussion, there was a tendency for gas exchange initially to worsen and then to gradually improve.