Excess neuropeptides in lung signal through endothelial cells to impair gas exchange

Although increased neuropeptides are often detected in lungs that exhibit respiratory distress, whether they contribute to the condition is unknown. Here, we show in a mouse model of neuroendocrine cell hyperplasia of infancy, a pediatric disease with increased pulmonary neuroendocrine cells (PNECs), excess PNEC-derived neuropeptides are responsible for pulmonary manifestations including hypoxemia. In mouse postnatal lung, prolonged signaling from elevated neuropeptides such as calcitonin gene-related peptide (CGRP) activate receptors enriched on endothelial cells, leading to reduced cellular junction gene expression, increased endothelium permeability, excess lung fluid, and hypoxemia. Excess fluid and hypoxemia were effectively attenuated by either prevention of PNEC formation, inactivation of CGRP gene, endothelium-specific inactivation of CGRP receptor gene, or treatment with CGRP receptor antagonist. Neuropeptides were increased in human lung diseases with excess fluid such as acute respiratory distress syndrome. Our findings suggest that restricting neuropeptide function may limit fluid and improve gas exchange in these conditions.

Iatrogenic intrathoracic encapsulated siliconoma from a ruptured breast implant

Our patient was a 57-year-old woman with a history of bilateral retropectoral silicone breast augmentation and axillary hyperhidrosis who underwent a bilateral thoracic sympathectomy via video-assisted thoracoscopic surgery by a surgeon at an outside hospital approximately 20 years ago. The left side required an open thoracotomy. Shortly after the surgery, she developed a left-sided Baker 4 capsular contracture and the left implant was noted to be ruptured. Both implants were exchanged. Several years later the patient began to experience progressive fatigue. Work-up revealed a left lung nodule and she underwent a biopsy that confirmed silicone granulomas. It was hypothesised that at the time of her initial thoracotomy the implant was violated resulting in silicone spillage into the thoracic cavity. The patient was referred to our institution for advanced management of her intrathoracic silicosis. The patient underwent bilateral removal of her silicone implants, total capsulectomy and needle-localised removal of her left thoracic silicone masses. She had an uneventful postoperative course with resolution of her fatigue.

Imaging of pulmonary hypertension in adults: a position paper from the Fleischner Society

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure greater than 20 mmHg and classified into five different groups sharing similar pathophysiologic mechanisms, haemodynamic characteristics, and therapeutic management. Radiologists play a key role in the multidisciplinary assessment and management of PH. A working group was formed from within the Fleischner Society based on expertise in the imaging and/or management of patients with PH, as well as experience with methodologies of systematic reviews. The working group identified key questions focusing on the utility of CT, MRI, and nuclear medicine in the evaluation of PH: a) Is noninvasive imaging capable of identifying PH? b) What is the role of imaging in establishing the cause of PH? c) How does imaging determine the severity and complications of PH? d) How should imaging be used to assess chronic thromboembolic PH before treatment? e) Should imaging be performed after treatment of PH? This systematic review and position paper highlights the key role of imaging in the recognition, work-up, treatment planning, and follow-up of PH.

Imaging of Pulmonary Hypertension in Adults: A Position Paper from the Fleischner Society

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure greater than 20 mm Hg and classified into five different groups sharing similar pathophysiologic mechanisms, hemodynamic characteristics, and therapeutic management. Radiologists play a key role in the multidisciplinary assessment and management of PH. A working group was formed from within the Fleischner Society based on expertise in the imaging and/or management of patients with PH, as well as experience with methodologies of systematic reviews. The working group identified key questions focusing on the utility of CT, MRI, and nuclear medicine in the evaluation of PH: (a) Is noninvasive imaging capable of identifying PH? (b) What is the role of imaging in establishing the cause of PH? (c) How does imaging determine the severity and complications of PH? (d) How should imaging be used to assess chronic thromboembolic PH before treatment? (e) Should imaging be performed after treatment of PH? This systematic review and position paper highlights the key role of imaging in the recognition, work-up, treatment planning, and follow-up of PH. This article is a simultaneous joint publication in Radiology and European Respiratory Journal. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article. © 2021 RSNA and the European Respiratory Society. Online supplemental material is available for this article.

Bleomycin-induced lung injury treated with venovenous extracorporeal membrane oxygenation (ECMO) and ultra-protective ventilator settings

Bleomycin treats malignancies, such as germ cell tumours and Hodgkin lymphoma. While efficacious, it can cause severe drug-induced lung injury. We present a 42-year-old patient with stage IIB seminoma treated with radical orchiectomy followed by adjuvant chemotherapy with bleomycin, etoposide and cisplatin. His postbleomycin course was complicated by the rapid onset of hypoxic respiratory failure, progressing to acute respiratory distress syndrome and requiring venovenous extracorporeal membrane oxygenation (VV-ECMO) support. Although the patient was treated with high dose systemic steroids and ultra-protective ventilator strategies to minimise ventilator-induced lung injury while on VV-ECMO, his lung injury failed to improve. Care was withdrawn 29 days later. Lung autopsy revealed diffuse organising pneumonia. We found six case reports (including this one) of bleomycin-induced lung injury requiring VV-ECMO with a cumulative survival of 33% (2/6). While VV-ECMO may be used to bridge patients to recovery or lung transplant, the mortality is high.

Multifocal Calcifying Fibrous Tumor at Seven Intrathoracic Sites in One Patient

Calcifying fibrous tumors are rare lesions that occur throughout the body. A 35-year-old man presented with exertional dyspnea. Computed tomography showed a polypoid mass abutting pericardium, diaphragm, and left chest wall, and a pleural-based lesion adjacent to T12. Thoracoscopy revealed a large mass with diaphragmatic stalk, two pleural-based nodules, and four diaphragmatic nodules. Pathologic analysis of resected lesions showed calcifying fibrous tumors. Three lesions contained heterogenous mutations associated with this tumor type. The patient is disease free 1 year later. Calcifying fibrous tumors should be recognized as rare multifocal pleural and diaphragmatic-based tumors. Complete resection leads to excellent survival for patients with this uncommon disease.

Staged Repair of an Aortic Pseudoaneurysm Secondary to Delayed Methylmethacrylate Plate Migration

Methylmethacrylate is a prosthetic material commonly used for the reconstruction of large chest wall defects. We present the first reported case of delayed methylmethacrylate plate migration, which resulted in an aortic pseudoaneurysm with aortopulmonary fistula. Treatment management, including staged repair combining endovascular and open approaches, is also discussed.

Fluid biopsy for circulating tumor cell identification in patients with early-and late-stage non-small cell lung cancer: a glimpse into lung cancer biology

Circulating tumor cell (CTC) counts are an established prognostic marker in metastatic prostate, breast and colorectal cancer, and recent data suggest a similar role in late stage non-small cell lung cancer (NSCLC). However, due to sensitivity constraints in current enrichment-based CTC detection technologies, there are few published data about CTC prevalence rates and morphologic heterogeneity in early-stage NSCLC, or the correlation of CTCs with disease progression and their usability for clinical staging. We investigated CTC counts, morphology and aggregation in early stage, locally advanced and metastatic NSCLC patients by using a fluid-phase biopsy approach that identifies CTCs without relying on surface-receptor-based enrichment and presents them in sufficiently high definition (HD) to satisfy diagnostic pathology image quality requirements. HD-CTCs were analyzed in blood samples from 78 chemotherapy-naïve NSCLC patients. 73% of the total population had a positive HD-CTC count (>0 CTC in 1 mL of blood) with a median of 4.4 HD-CTCs mL⁻¹ (range 0-515.6) and a mean of 44.7 (±95.2) HD-CTCs mL⁻¹. No significant difference in the medians of HD-CTC counts was detected between stage IV (n = 31, range 0-178.2), stage III (n = 34, range 0-515.6) and stages I/II (n = 13, range 0-442.3). Furthermore, HD-CTCs exhibited a uniformity in terms of molecular and physical characteristics such as fluorescent cytokeratin intensity, nuclear size, frequency of apoptosis and aggregate formation across the spectrum of staging. Our results demonstrate that despite stringent morphologic inclusion criteria for the definition of HD-CTCs, the HD-CTC assay shows high sensitivity in the detection and characterization of both early- and late-stage lung cancer CTCs. Extensive studies are warranted to investigate the prognostic value of CTC profiling in early-stage lung cancer. This finding has implications for the design of extensive studies examining screening, therapy and surveillance in lung cancer patients.

Unfavourable consequences of chronic cardiac HIF-1α stabilization

AIMS

The hypoxia-inducible factor-1 (HIF-1) is the master modulator of hypoxic gene expression. The effects of chronically stabilized cardiac HIF-1α and its role in the diseased heart are not precisely known. The aims of this study were as follows: (i) to elucidate consequences of HIF-1α stabilization in the heart; (ii) to analyse long-term effects of HIF-1α stabilization with ageing and the ability of the HIF-1α overexpressing hearts to respond to increased mechanical load; and (iii) to analyse HIF-1α protein levels in failing heart samples.

METHODS AND RESULTS

In a cardiac-specific HIF-1α transgenic mouse model, constitutive expression of HIF-1α leads to changes in capillary area and shifts the cardiac metabolism towards glycolysis with a net increase in glucose uptake. Furthermore, Ca(2+) handling is altered, with increased Ca(2)(+) transients and faster intracellular [Ca(2+)] decline. These changes are associated with decreased expression of sarcoplasmic/endoplasmic reticulum calcium ATPase 2a but elevated phosphorylation of phospholamban. HIF-1α transgenic mice subjected to transverse aortic constriction exhibited profound cardiac decompensation. Moreover, cardiomyopathy was also seen in ageing transgenic mice. In parallel, we found an increased stabilization of HIF-1α in heart samples of patients with end-stage heart failure.

CONCLUSION

Changes induced with transgenic cardiac HIF-1α possibly mediate beneficial effects in the short term; however, with increased mechanical load and ageing they become detrimental for cardiac function. Together with the finding of increased HIF-1α protein levels in samples from human patients with cardiomyopathy, these data indicate that chronic HIF-1α stabilization drives autonomous pathways that add to disease progression.

Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association

Venous thromboembolism (VTE) is responsible for the hospitalization of >250 000 Americans annually and represents a significant risk for morbidity and mortality. Despite the publication of evidence-based clinical practice guidelines to aid in the management of VTE in its acute and chronic forms, the clinician is frequently confronted with manifestations of VTE for which data are sparse and optimal management is unclear. In particular, the optimal use of advanced therapies for acute VTE, including thrombolysis and catheter-based therapies, remains uncertain. This report addresses the management of massive and submassive pulmonary embolism (PE), iliofemoral deep vein thrombosis (IFDVT),and chronic thromboembolic pulmonary hypertension (CTEPH). The goal is to provide practical advice to enable the busy clinician to optimize the management of patients with these severe manifestations of VTE. Although this document makes recommendations for management, optimal medical decisions must incorporate other factors, including patient wishes, quality of life, and life expectancy based on age and comorbidities. The appropriateness of these recommendations for a specific patient may vary depending on these factors and will be best judged by the bedside clinician.

Cardiac-specific overexpression of HIF-1{alpha} prevents deterioration of glycolytic pathway and cardiac remodeling in streptozotocin-induced diabetic mice

Defective glycolysis and angiogenesis in the heart of diabetic patients and in experimental diabetic animal models have been reported. The aim of this study was to determine whether overexpression of hypoxia-inducible factor (HIF)-1alpha protects from myocardial injury in diabetic mice by increasing myocardial glycolysis and angiogenesis. Cardiac-specific HIF-1alpha-overexpressing transgenic and age-matched wild-type control mice were treated with streptozotocin to induce diabetes. Changes in glucose transporters, glycolytic enzymes, angiogenic factors and cardiac morphology were examined in the hearts by real-time RT-PCR, Western blotting, enzymatic assay, and histological assays. HIF-1alpha overexpression elevated hexokinase II (HK-II) protein level and total HK activity in nondiabetic heart and prevented the decreases in HK-II mRNA, protein, and total HK activity in diabetic heart. In addition, the reduction of glucose transporter I, but not glucose transporter 4, was restored in HIF transgenic mouse heart along with a recovery of myocardium ATP production. HIF-1alpha overexpression also normalized diabetes-reduced vascular endothelial growth factor concentration along with a sustained myocardial capillary density and an inhibition of cardiomyocyte hypertrophy and cardiac fibrosis. Therefore, elevation of HIF-1alpha provides a cardiac protection from diabetic-induced impairment in glucose metabolism and angiogenesis via up-regulation of HIF-1 target genes.

Human airway contraction and formoterol-induced relaxation is determined by Ca2+ oscillations and Ca2+ sensitivity

The etiology of airway hyperresponsiveness associated with asthma requires an understanding of the regulatory mechanisms mediating human airway smooth muscle cell (SMC) contraction. The objective of this study was to determine how human airway SMC contraction (induced by histamine) and relaxation (induced by formoterol) are regulated by Ca(2+) oscillations and Ca(2+) sensitivity. The responses of human small airways and their associated SMCs were studied in human lung slices cut from agarose-inflated lungs. Airway contraction was measured with phase-contrast video microscopy. Ca(2+) signaling and Ca(2+) sensitivity of airway SMCs were measured with two-photon fluorescence microscopy and Ca(2+)-permeabilized lung slices. The agonist histamine induced contraction of human small airways by stimulating both an increase in intracellular Ca(2+) concentration in the SMCs in the form of oscillatory Ca(2+) waves and an increase in Ca(2+) sensitivity. The frequency of the Ca(2+) oscillations increased with histamine concentration, and correlated with increased contraction. Formoterol induced airway relaxation at low concentrations by initially decreasing SMC Ca(2+) sensitivity. At higher concentrations, formoterol additionally slowed or inhibited the Ca(2+) oscillations of the SMCs to relax the airways. The action of formoterol was only slowly reversed. Human lung slices provide a powerful experimental assay for the investigation of small airway physiology and pharmacology. Histamine induces contraction by simultaneously increasing SMC Ca(2+) signaling and Ca(2+) sensitivity. Formoterol induces long-lasting relaxation by initially reducing the Ca(2+) sensitivity and, subsequently, the frequency of the Ca(2+) oscillations of the airway SMCs.

The effect of PVC packaging on the acidity of 0.9% saline

Intravenous fluids in polyvinyl chloride (PVC) packaging are known to be acidic. We proposed to determine the effect of PVC packaging on the pH of 0.9% saline solutions by comparing the predicted and measured pH of 0.9% saline equilibrated with atmospheric carbon dioxide and the measured pH of commercial solutions of 0.9% saline in PVC and polypropylene packaging. Calculation of pH was made from available physical chemistry constants and data. Measurement was made of the pH of 12 samples of prepared 0.9% saline equilibrated with atmospheric carbon dioxide. Comparison with the pH of seven commercial samples of saline in PVC packaging for intravenous use was undertaken. Further comparison was made between commercial samples of 0.9% saline in PVC or polypropylene packaging. The calculated pH of 0.9% saline was 5.61 at 20 degrees C. The median pH of the prepared samples was statistically significantly less acidic than the median pH of the PVC packaged samples for intravenous use: 5.47 vs 4.60, P < 0.05. The median pH of the PVC packaged saline was also statistically significantly more acidic than the pH of the polypropylene packaged saline: 4.62 vs 5.71, P < 0.05. The acidity of the intravenous solutions of 0.9% saline packaged in PVC was much greater than expected and is only partially explained by dissolved carbon dioxide. This acidity could be a result of packaging in PVC.