Estrogen Signaling and Portopulmonary Hypertension: The Pulmonary Vascular Complications of Liver Disease Study (PVCLD2).

BACKGROUND AND AIMS: Portopulmonary hypertension (POPH) was previously associated with a single-nucleotide polymorphism (SNP) rs7175922 in aromatase (cytochrome P450 family 19 subfamily A member 1 [CYP19A1]). We sought to determine whether genetic variants and metabolites in the estrogen signaling pathway are associated with POPH. APPROACH AND RESULTS: We performed a multicenter case-control study. POPH patients had mean pulmonary artery pressure >25 mm Hg, pulmonary vascular resistance >240 dyn-sec/cm-5 , and pulmonary artery wedge pressure ≤15 mm Hg without another cause of pulmonary hypertension. Controls had advanced liver disease, right ventricular (RV) systolic pressure <40 mm Hg, and normal RV function by echocardiography. We genotyped three SNPs in CYP19A1 and CYP1B1 using TaqMan and imputed SNPs in estrogen receptor 1 using genome-wide markers. Estrogen metabolites were measured in blood and urine samples. There were 37 patients with POPH and 290 controls. Mean age was 57 years, and 36% were female. The risk allele A in rs7175922 (CYP19A1) was significantly associated with higher levels of estradiol (P = 0.02) and an increased risk of POPH (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.12-4.91; P = 0.02) whereas other SNPs were not. Lower urinary 2-hydroxyestrogen/16-α-hydroxyestrone (OR per 1-ln decrease = 2.04; 95% CI, 1.16-3.57; P = 0.01), lower plasma levels of dehydroepiandrosterone-sulfate (OR per 1-ln decrease = 2.38; 95% CI, 1.56-3.85; P < 0.001), and higher plasma levels of 16-α-hydroxyestradiol (OR per 1-ln increase = 2.16; 95% CI, 1.61-2.98; P < 0.001) were associated with POPH. CONCLUSIONS: Genetic variation in aromatase and changes in estrogen metabolites were associated with POPH.

Volatile organic compounds in bile can distinguish pancreatic cancer from chronic pancreatitis: a prospective observational study.

BACKGROUND: Early and accurate diagnosis of pancreatic cancer is important. Our aim was to identify potential volatile organic compounds (VOCs) in the bile that can help distinguish pancreatic cancer from chronic pancreatitis. METHODS: In this prospective observational study, bile was aspirated from patients undergoing endoscopic retrograde cholangiopancreatography for chronic pancreatitis and pancreatic cancer, and the gaseous headspace was analyzed using mass spectrometry. RESULTS: The study included a discovery cohort of 57 patients (46 pancreatic cancer, 11 chronic pancreatitis) and a validation cohort of 31 patients (19 and 12, respectively). Using logistic regression analysis, the model [0.158 × age + 9.747 × log (ammonia) - 3.994 × log (acetonitrile) + 5.044 × log (trimethylamine) - 30.23] successfully identified patients with pancreatic cancer with a sensitivity of 93.5 % and specificity of 100 % (likelihood ratio 40.9, area under the curve 0.98, 95 % confidence interval 0.95 - 1.00). The diagnostic accuracy of this model was confirmed in the second independent validation cohort. CONCLUSION: The measurement of VOCs in bile helped to accurately distinguish pancreatic cancer from chronic pancreatitis.

Chronic Beryllium Disease: Update on a Moving Target.

Beryllium exposure remains an ongoing occupational health concern for workers worldwide. Since the initial Occupational Safety and Health Administration (OSHA) ruling on a permissible exposure limit (PEL) for beryllium in 1971, our understanding of the risks of beryllium sensitization and chronic beryllium disease (CBD) has evolved substantially. A new OSHA ruling released in early 2017 and implemented in late 2018 reduced the PEL for beryllium, increased requirements for medical screening and monitoring, and may ultimately enhance worker protection. This review highlights advances in our understanding of the pathway from beryllium exposure to sensitization and progression to CBD that guided the development of this OSHA ruling. Screening workers exposed to beryllium and management of CBD will also be discussed. Finally, we will discuss the role of beryllium as a cause of morbidity and mortality among exposed workers in this potentially preventable occupational lung disease.

Breath Metabolomics Provides an Accurate and Noninvasive Approach for Screening Cirrhosis, Primary, and Secondary Liver Tumors.

Hepatocellular carcinoma (HCC) and secondary liver tumors, such as colorectal cancer liver metastases are significant contributors to the overall burden of cancer-related morality. Current biomarkers, such as alpha-fetoprotein (AFP) for HCC, result in too many false negatives, necessitating noninvasive approaches with improved sensitivity. Volatile organic compounds (VOCs) detected in the breath of patients can provide valuable insight into disease processes and can differentiate patients by disease status. Here, we investigate whether 22 VOCs from the breath of 296 patients can distinguish those with no liver disease (n = 54), cirrhosis (n = 30), HCC (n = 112), pulmonary hypertension (n = 49), or colorectal cancer liver metastases (n = 51). This work extends previous studies by evaluating the ability for VOC signatures to differentiate multiple diseases in a large cohort of patients. Pairwise disease comparisons demonstrated that most of the VOCs tested are present in significantly different relative abundances (false discovery rate P < 0.1), indicating broad impacts on the breath metabolome across diseases. A predictive model developed using random forest machine learning and cross validation classified patients with 85% classification accuracy and 75% balanced accuracy. Importantly, the model detected HCC with 73% sensitivity compared with 53% for AFP in the same cohort. An added value of this approach is that influential VOCs in the predictive model may provide insight into disease etiology. Acetaldehyde and acetone, both of which have roles in tumor promotion, were considered important VOCs for differentiating disease groups in the predictive model and were increased in patients with cirrhosis and HCC compared to patients with no liver disease (false discovery rate P < 0.1). Conclusion: The use of machine learning and breath VOCs shows promise as an approach to develop improved, noninvasive screening tools for chronic liver disease and primary and secondary liver tumors.

Comparison of volatile organic compound profiles in exhaled breath versus plasma headspace in different diseases.

Breath analysis is the study of volatile organic compounds (VOC's) in exhaled breath. This analysis provides information on the body's condition. In this study we investigated the relationship between 22 VOC's detected in exhaled breath and plasma headspace using a selected ion flow tube mass spectrometer (SYFT-MS). We compared pairs of exhaled breath and plasma samples from patients with pulmonary hypertension inflammatory bowel disease (IBD), and IBD patients after J-pouch surgery (pouch group). Half of the measured VOC's from exhaled breath were significantly associated with the VOC's from plasma headspace. Interestingly, six breath VOC's (trimethyl amine (FDR p = 0.02), hydrogen sulfide (FDR p = 7.64 × 10-30), ethanol (FDR p = 1.56 × 10-4), dimethyl sulfide (FDR p = 5.70 × 10-19), benzene (FDR p = 8.40 × 10-27), and acetaldehyde (FDR p = 4.27 × 10-17)) and two plasma headspace VOC's (1-Octene (FDR p = 0.02) and 2-propanol (FDR p = 2.47 × 10-9)) were able to differentiate between the three groups. Breath and plasma headspace share a similar signature with significant association in half of the measured VOCs. The disease discriminatory capacity of breath and plasma headspace appear to be different. Therefore, using the VOC's print from both breath and plasma headspace may better help diagnose patients.

O-GlcNAc Transferase Regulates Angiogenesis in Idiopathic Pulmonary Arterial Hypertension.

Idiopathic pulmonary arterial hypertension (IPAH) is considered a vasculopathy characterized by elevated pulmonary vascular resistance due to vasoconstriction and/or lung remodeling such as plexiform lesions, the hallmark of the PAH, as well as cell proliferation and vascular and angiogenic dysfunction. The serine/threonine hydroxyl-linked N-Acetylglucosamine (O-GlcNAc) transferase (OGT) has been shown to drive pulmonary arterial smooth muscle cell (PASMC) proliferation in IPAH. OGT is a cellular nutrient sensor that is essential in maintaining proper cell function through the regulation of cell signaling, proliferation, and metabolism. The aim of this study was to determine the role of OGT and O-GlcNAc in vascular and angiogenic dysfunction in IPAH. Primary isolated human control and IPAH patient PASMCs and pulmonary arterial endothelial cells (PAECs) were grown in the presence or absence of OGT inhibitors and subjected to biochemical assessments in monolayer cultures and tube formation assays, in vitro vascular sprouting 3D spheroid co-culture models, and de novo vascularization models in NODSCID mice. We showed that knockdown of OGT resulted in reduced vascular endothelial growth factor (VEGF) expression in IPAH primary isolated vascular cells. In addition, specificity protein 1 (SP1), a known stimulator of VEGF expression, was shown to have higher O-GlcNAc levels in IPAH compared to control at physiological (5 mM) and high (25 mM) glucose concentrations, and knockdown resulted in decreased VEGF protein levels. Furthermore, human IPAH PAECs demonstrated a significantly higher degree of capillary tube-like structures and increased length compared to control PAECs. Addition of an OGT inhibitor, OSMI-1, significantly reduced the number of tube-like structures and tube length similar to control levels. Assessment of vascular sprouting from an in vitro 3D spheroid co-culture model using IPAH and control PAEC/PASMCs and an in vivo vascularization model using control and PAEC-embedded collagen implants demonstrated higher vascularization in IPAH compared to control. Blocking OGT activity in these experiments, however, altered the vascular sprouting and de novo vascularization in IPAH similar to control levels when compared to controls. Our findings in this report are the first to describe a role for the OGT/O-GlcNAc axis in modulating VEGF expression and vascularization in IPAH. These findings provide greater insight into the potential role that altered glucose uptake and metabolism may have on the angiogenic process and the development of plexiform lesions. Therefore, we believe that the OGT/O-GlcNAc axis may be a potential therapeutic target for treating the angiogenic dysregulation that is present in IPAH.

Breath analysis in gastrointestinal graft-versus-host disease after allogeneic hematopoietic cell transplantation.

Volatile organic compounds (VOCs) are generated during pathologic processes, and their assessment can be used to diagnose and monitor a variety of diseases. Given the role of the microbiome in graft-versus-host disease (GVHD), we hypothesized that microorganisms producing volatile metabolites may alter VOCs expelled in breath in patients with gastrointestinal (GI) GVHD. In this pilot study, exhaled breath samples were obtained from 19 patients with grade 2 to 4 acute GI GVHD, 10 patients with no GVHD at day 100, and 10 healthy control subjects; the samples were analyzed by using mass spectrometry. Overall, nine (47%) patients had grade 2 GVHD, eight (42%) patients had grade 3 GVHD, and two (11%) patients had grade 4 GVHD; 26% had upper GI, 21% had lower GI, and 53% had both upper and lower GI manifestations. Stepwise canonical discriminant analysis identified 5 VOCs distinguishing patients with and without GI GVHD: 2-propanol, acetaldehyde, dimethyl sulfide, isoprene, and 1-decene (Wilks' Λ, 0.43; F statistic, 6.08; P = .001). The model correctly classified 89% (17 of 19) and 90% (9 of 10) of patients with and without GI GVHD, respectively. Breath analysis is a feasible and promising noninvasive method to detect acute GI GVHD. Further study of serial breath analysis and the gut microbiome in a larger cohort are ongoing to validate these findings.

Evaluation and Management of Obesity Hypoventilation Syndrome. An Official American Thoracic Society Clinical Practice Guideline.

Background: The purpose of this guideline is to optimize evaluation and management of patients with obesity hypoventilation syndrome (OHS).Methods: A multidisciplinary panel identified and prioritized five clinical questions. The panel performed systematic reviews of available studies (up to July 2018) and followed the Grading of Recommendations, Assessment, Development, and Evaluation evidence-to-decision framework to develop recommendations. All panel members discussed and approved the recommendations.Recommendations: After considering the overall very low quality of the evidence, the panel made five conditional recommendations. We suggest that: 1) clinicians use a serum bicarbonate level <27 mmol/L to exclude the diagnosis of OHS in obese patients with sleep-disordered breathing when suspicion for OHS is not very high (<20%) but to measure arterial blood gases in patients strongly suspected of having OHS, 2) stable ambulatory patients with OHS receive positive airway pressure (PAP), 3) continuous positive airway pressure (CPAP) rather than noninvasive ventilation be offered as the first-line treatment to stable ambulatory patients with OHS and coexistent severe obstructive sleep apnea, 4) patients hospitalized with respiratory failure and suspected of having OHS be discharged with noninvasive ventilation until they undergo outpatient diagnostic procedures and PAP titration in the sleep laboratory (ideally within 2-3 mo), and 5) patients with OHS use weight-loss interventions that produce sustained weight loss of 25% to 30% of body weight to achieve resolution of OHS (which is more likely to be obtained with bariatric surgery).Conclusions: Clinicians may use these recommendations, on the basis of the best available evidence, to guide management and improve outcomes among patients with OHS.

Non-invasive screening for pulmonary hypertension in idiopathic pulmonary fibrosis.

BACKGROUND: Pulmonary hypertension (PH) is a common complication of idiopathic pulmonary fibrosis (IPF) that is associated with poor prognosis. Noninvasive screening for PH in IPF patients is challenging and a combination of several noninvasive determinations can improve discrimination. METHODS: We included 235 IPF patients who underwent right heart catheterization (RHC) as part of the lung transplant evaluation. We measured electrocardiographic (ECG) and echocardiographic variables as well as the pulmonary artery (PA) and ascending aorta (AA) diameters on chest CT. We recorded results of arterial blood gases (ABG), pulmonary function (PFT) and 6-min walk tests (6MWT). RESULTS: Several variables were predictors of PH in IPF patients in univariable models including a lower arterial oxygenation and 6MWT distance; worse right ventricular (RV) function, rightward deviation of the QRS axis and a higher FVC/DLCOc ratio, PA/AA diameter ratio, and estimated RV systolic pressure. In multivariable analysis, a worse RV function and higher PA/AA ratio remained predictors of PH (c-index 0.75 (0.65-0.84)). Similarly, a worse RV function, a higher PA/AA ratio and a rightward QRS axis deviation were independent predictors of precapillary PH (c-index 0.86 (0.76-0.92)). A combination of PA/AA diameter ratio <1.1, a QRS axis <90° and normal RV function showed a negative predictive value of 85% for precapillary PH. CONCLUSIONS: There are significant differences in ECG, echocardiographic, chest CT, PFT and ABG parameters between IPF patients with and without PH. However, these noninvasive tests alone or combination have limited discrimination ability for PH screening in IPF.

Mortality Outcomes of Patients with Chronic Kidney Disease and Chronic Obstructive Pulmonary Disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with higher mortality in the general population. We studied the associations between COPD and death among chronic kidney disease (CKD) patients along with reporting cause-specific death data. METHODS: We included 56,960 patients with stages 3 and 4 CKD who were followed in a large health care system. Associations between COPD and all-cause mortality and various causes of death (respiratory deaths, cardiovascular deaths, malignancy-related deaths and deaths due to other reasons) were studied using the Cox proportional hazards and competing risk models. RESULTS: Out of 56,960 CKD patients, 4.7% (n = 2,667) had underlying COPD. Old age, presence of diabetes, hypertension, coronary artery disease, congestive heart failure, and smoking were associated with higher risk for COPD. During a median follow-up of 3.7 years, 15,969 patients died. After covariate adjustment, COPD was associated with a 41% increased risk (95% CI 1.31-1.52) for all-cause mortality, and fourfold increased risk (sub-hazard ratio 4.36, 95% CI 3.54-5.37) for respiratory-related deaths. In a sensitivity analysis that was performed by defining COPD as the use of relevant International Classification of Diseases-9 codes and medications used to treat COPD, similar results were noted. CONCLUSIONS: COPD is associated with higher risk for death among those with CKD, and an underlying lung disease accounts for significant proportion of deaths. These data highlight the need for further prospective studies to understand the underlying mechanisms and potential interventions to improve outcomes in this population.

Novel methods in pulmonary hypertension phenotyping in the age of precision medicine (2015 Grover Conference series).

Among pulmonary vascular diseases, pulmonary hypertension (PH) is the best studied and has been the focus of our work. The current classification of PH is based on a relatively simple combination of patient characteristics and hemodynamics. This leads to inherent limitations, including the inability to customize treatment and the lack of clarity from a more granular identification based on individual patient phenotypes. Accurate phenotyping of PH can be used in the clinic to select therapies and determine prognosis and in research to increase the homogeneity of study cohorts. Rapid advances in the mechanistic understanding of the disease, improved imaging methods, and innovative biomarkers now provide an opportunity to define novel PH phenotypes. We have recently shown that altered metabolism may affect nitric oxide levels and protein glycosylation, the peripheral circulation (which may provide insights into the response to therapy), and exhaled-breath analysis (which may be useful in disease evaluation). This review is based on a talk presented during the 2015 Grover Conference and highlights the relevant literature describing novel methods to phenotype pulmonary arterial hypertension patients by using approaches that involve the pulmonary and systemic (peripheral) vasculature. In particular, abnormalities in metabolism, the pulmonary and peripheral circulation, and exhaled breath in PH may help identify phenotypes that can be the basis for a precision-medicine approach to PH management. These approaches may also have a broader scope and may contribute to a better understanding of other diseases, such as asthma, diabetes, and cancer.

The Rise and Fall of Hyaluronan in Respiratory Diseases.

In normal airways, hyaluronan (HA) matrices are primarily located within the airway submucosa, pulmonary vasculature walls, and, to a lesser extent, the alveoli. Following pulmonary injury, elevated levels of HA matrices accumulate in these regions, and in respiratory secretions, correlating with the extent of injury. Animal models have provided important insight into the role of HA in the onset of pulmonary injury and repair, generally indicating that the induction of HA synthesis is an early event typically preceding fibrosis. The HA that accumulates in inflamed airways is of a high molecular weight (>1600 kDa) but can be broken down into smaller fragments (<150 kDa) by inflammatory and disease-related mechanisms that have profound effects on HA pathobiology. During inflammation in the airways, HA is often covalently modified with heavy chains from inter-alpha-inhibitor via the enzyme tumor-necrosis-factor-stimulated-gene-6 (TSG-6) and this modification promotes the interaction of leukocytes with HA matrices at sites of inflammation. The clearance of HA and its return to normal levels is essential for the proper resolution of inflammation. These data portray HA matrices as an important component of normal airway physiology and illustrate its integral roles during tissue injury and repair among a variety of respiratory diseases.

Volatile Organic Compounds in Urine for Noninvasive Diagnosis of Malignant Biliary Strictures: A Pilot Study.

BACKGROUND: The use of volatile organic compounds (VOCs) in bile was recently studied and appeared promising for diagnosis of malignancy. Noninvasive diagnosis of malignant biliary strictures by using VOCs in urine has not been studied. AIM: To identify potential VOCs in urine to diagnose malignant biliary strictures. METHODS: In this prospective cross-sectional study, urine was obtained immediately prior to ERCP from consecutive patients with biliary strictures. Selected-ion flow-tube mass spectrometry was used to analyze the concentration of VOCs in urine samples. RESULTS: Fifty-four patients with biliary strictures were enrolled. Fifteen patients had malignant stricture [six cholangiocarcinoma (CCA) and nine pancreatic cancer], and 39 patients had benign strictures [10 primary sclerosing cholangitis (PSC) and 29 with benign biliary conditions including chronic pancreatitis and papillary stenosis]. The concentration of several compounds (ethanol and 2-propanol) was significantly different in patients with malignant compared with benign biliary strictures (p < 0.05). Using receiver operating characteristic curve analysis, we developed a model for the diagnosis of malignant biliary strictures adjusted for age and gender based on VOC levels of 2-propranol, carbon disulfide, and trimethyl amine (TMA). The model [-2.4191 * log(2-propanol) + 1.1617 * log(TMA) - 1.2172 * log(carbon disulfide)] ≥ 7.73 identified the patients with malignant biliary stricture [area under the curve (AUC = 0.83)], with 93.3 % sensitivity and 61.5 % specificity (p = 0.009). Comparing patients with CCA and PSC, the model [38.864 * log(ethane) - 3.989 * log(1-octene)] ≤ 169.9 could identify CCA with 80 % sensitivity and 100 % specificity (AUC = 0.9). CONCLUSIONS: Measurement of VOCs in urine may diagnose malignant biliary strictures noninvasively.

Volatile organic compounds in bile for early diagnosis of cholangiocarcinoma in patients with primary sclerosing cholangitis: a pilot study.

BACKGROUND: The diagnosis of cholangiocarcinoma (CCA) in patients with primary sclerosing cholangitis (PSC) is particularly difficult. The role of volatile organic compounds (VOCs) for diagnosis of CCA in patients with PSC is not known. OBJECTIVE: Our aim was to identify potential VOCs in the headspaces (gas above the sample) in bile that may predict CCA in patients with PSC. DESIGN: Prospective cross-sectional study. SETTING: Referral center. PATIENTS: A total of 32 patients undergoing ERCP for PSC and for CCA complicating PSC. INTERVENTIONS: ERCP, bile aspiration. MAIN OUTCOME MEASUREMENTS: Selected ion flow tube mass spectrometry was used to analyze the concentration of 22 prevalent VOCs in bile samples. Logistic regression analysis was performed to build a predictive model for diagnosis of CCA. RESULTS: Levels of several compounds (ethanol, acrylonitrile, acetonitrile, acetaldehyde, benzene, carbon disulfide, dimethyl sulfide, 2-propranolol) were significantly different in patients with CCA complicating PSC compared with those having PSC (P < .05). By using receiver operating characteristic curve analysis, we developed a model for the diagnosis of CCA adjusted for age and sex based on VOC levels of acrylonitrile, 3-methyl hexane, and benzene. The model (2.3239*log [acrylonitrile] + 0.9871*log [3-methyl hexane] + 0.8448*log [benzene]) < -0.12 identified the patients with CCA (area under the curve [AUC] = 0.89), with 90.5% sensitivity and 72.7% specificity (P = .02). LIMITATIONS: Sample size. CONCLUSION: The measurement of VOCs in biliary fluid may be useful to diagnose CCA in patients with PSC. A larger study with a longitudinal study design is required to confirm our pilot observations to diagnose CCA early in patients with PSC. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01565460.).

An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease.

RATIONALE: Beryllium continues to have a wide range of industrial applications. Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD). OBJECTIVES: The purpose of this statement is to increase awareness and knowledge about beryllium exposure, BeS, and CBD. METHODS: Evidence was identified by a search of MEDLINE. The committee then summarized the evidence, drew conclusions, and described their approach to diagnosis and management. MAIN RESULTS: The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD. A confirmed abnormal beryllium lymphocyte proliferation test without evidence of lung disease is diagnostic of BeS. BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD. The determinants of progression from BeS to CBD are uncertain, but higher exposures and the presence of a genetic variant in the HLA-DP ß chain appear to increase the risk. Periodic evaluation of affected individuals can detect disease progression (from BeS to CBD, or from mild CBD to more severe CBD). Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline. CONCLUSIONS: Medical surveillance in workplaces that use beryllium-containing materials can identify individuals with BeS and at-risk groups of workers, which can help prioritize efforts to reduce inhalational and dermal exposures.

Leptin deficiency recapitulates the histological features of pulmonary arterial hypertension in mice.

UNLABELLED: Leptin is a neuroendocrine peptide released by adipose tissue that enhances metabolism and acts on the hypothalamus to suppress appetite. Leptin also regulates aspects of cardiovascular function and low serum leptin has been associated with increased mortality in humans. We hypothesized that leptin deficiency alters the structure and function of the pulmonary vasculature. METHODS: We examined two groups of C57BL/6 male mice aged 12 weeks: five ob/ob (B6.VLepob/ob) leptin-deficient and five wild type (WT) (C57BL/6) control mice. As expected, weight was significantly greater in ob/ob mice relative to WT mice [weight (g), Mean±SD): ob/ob 52±2.5 g, wild type 30±2.5 g; p<0.001]. The pulmonary vasculature of ob/ob mice and WT control animals was examined by histology, immunohistochemistry and immunofluorescence staining. RESULTS: Pulmonary arterial wall thickness was significantly increased in ob/ob mice relative to WT littermates [median (interquartile range) distance in pixels: ob/ob 0.13 (0.05-0.18), wild type 0.03 (0.02-0.04); p=0.001]. The ob/ob mice also exhibited significant right ventricular hypertrophy in comparison to control animals [RV thickness (Mean±SD): ob/ob 0.75±0.19, wild type; 0.58±0.13 p<0.001]. We observed substantial macrophage infiltration and abundant proliferation of myofibroblasts and fibroblasts in histological sections of pulmonary arterioles of ob/ob mice. In addition, we noted increased hyaluronan deposition, colocalizing with SMC-actin in the pulmonary vasculature of ob/ob mice relative to WT controls. CONCLUSIONS: The pulmonary pathology of leptin deficiency in ob/ob mice recapitulates many of the histological features of pulmonary vascular diseases, including pulmonary hypertension, suggesting that leptin deficiency is associated to the pathogenesis of pulmonary vascular disease.

Volatile organic compounds in bile can diagnose malignant biliary strictures in the setting of pancreatic cancer: a preliminary observation.

BACKGROUND: Ascertaining the nature of biliary strictures is challenging. The role of volatile organic compounds (VOCs) in bile in determining the cause of biliary strictures is not known. OBJECTIVE: To identify potential VOCs in the headspaces (gas above the sample) of bile in patients with malignant biliary strictures from pancreatic cancer. DESIGN: Prospective cross-sectional study. SETTING: Referral center. PATIENTS: Prospective study in which bile was aspirated in 96 patients undergoing ERCP for benign and malignant conditions. MAIN OUTCOME MEASUREMENTS: Selected ion flow tube mass spectrometry (VOICE200R SIFT-MS instrument; Syft Technologies Ltd, Christchurch, New Zealand) was used to analyze the headspace and to build a predictive model for pancreatic cancer. RESULTS: The headspaces from 96 bile samples were analyzed, including 24 from patients with pancreatic cancer and 72 from patients with benign biliary conditions. The concentrations of 6 compounds (acetaldehyde, acetone, benzene, carbon disulfide, pentane, and trimethylamine [TMA]) were increased in patients with pancreatic cancer compared with controls (P < .05). By using receiver-operating characteristic curve analysis, we developed a model for the diagnosis of pancreatic cancer based on the levels of TMA, acetone, isoprene, dimethyl sulfide, and acetaldehyde. The model [10.94 + 1.8229* log (acetaldehyde) + 0.7600* log (acetone) - 1.1746* log (dimethyl sulfide) + 1.0901* log (isoprene) - 2.1401 * log (trimethylamine) ≥ 10] identified the patients with pancreatic cancer (area under the curve = 0.85), with 83.3% sensitivity and 81.9% specificity. LIMITATIONS: Sample size. CONCLUSIONS: The measurement of biliary fluid VOCs may help to distinguish malignant from benign biliary strictures. Further studies are warranted to validate these observations. (Clinical Trial Registration Number NCT01565460.).

Modification of hyaluronan by heavy chains of inter-α-inhibitor in idiopathic pulmonary arterial hypertension.

We previously reported an altered hyaluronan (HA) metabolism in idiopathic pulmonary arterial hypertension (IPAH) lung tissue and cultured smooth muscle cells. Hyaluronan was present in the smooth muscle cell layer surrounding the pulmonary vasculature and in plexigenic lesions. Additionally, cultured pulmonary artery smooth muscle cells produced spontaneous HA "cable" structures, without additional stimuli, that were leukocyte-adhesive. We now present evidence that the HA that accumulates in IPAH plexigenic lesions is a pathological form of HA in which heavy chains (HCs) from the serum-derived proteoglycan inter-α-inhibitor are covalently attached to the HA backbone to form a pathological HC-HA complex. CD45-positive leukocytes were identified within these HC-HA matrices. Elevated mRNA levels of the enzyme that transfers HCs to HA, known as tumor necrosis factor-stimulated gene 6, were detected in IPAH lung tissue.