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Bowel dysfunction, in the form of constipation and/or incontinence, is one of the most prevalent and life-impacting co-morbidities associated with spinal cord injury (SCI) with no long- term treatment available. The extent to which SCI-induced changes in the colon (e.g. inflammation, fibrosis, and reduced enteric neuron density) cause progressive dysfunction is understudied. There remains a significant unmet need to develop strategies to prevent or reverse bowel dysfunction after SCI. This need remains, in part, due to the lack of a mouse model which recapitulates the human condition. We hypothesized that a T3 spinal transection in mice would trigger bowel dysfunction alongside early colonic inflammation and downstream remodeling of the colon musculature as seen in both humans and rats after SCI. Bowel dysfunction was defined as increased number of fecal pellets within the colon, smaller pellet size, and decreased water content in the stool. The number of fecal pellets within the colon increased significantly in animals receiving SCI compared to sham (laminectomy only) injuries by 4 days post injury (dpi) and persisted to 21dpi. Furthermore, fecal pellet size was significantly decreased in the SCI animals at 21dpi and trended toward decreased water content. Together, these functional measurements are indicative of chronic bowel dysfunction after T3 transection. We next molecularly interrogated whole colon tissue for inflammatory cytokine levels and found increased levels of IFN-γ at 4 dpi but not at 21dpi and found increased collagen deposition in the colonic musculature at both 4 and 21 dpi in the SCI versus sham animals. The acute spike in INF-γ and deposition of collagen after injury are consistent with our hypothesis that T3 transection causes acute inflammation followed by remodeling of the colon wall. Establishing this mouse model will enable further interrogation of cell-type specific responses and signaling pathways using transgenic models. T32 Fellowship in Physiology (GM118292) and T32 Fellowship Neurobiology of CNS Injury & Repair (5T32 NS077889) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

BACKGROUND: Smokers manifest varied phenotypes of pulmonary impairment. RESEARCH QUESTION: Which pulmonary phenotypes are associated with coronary artery disease (CAD) in smokers? STUDY DESIGN AND METHODS: We analyzed data from the University of Pittsburgh COPD Specialized Center for Clinically Oriented Research (SCCOR) cohort (n = 481) and the Genetic Epidemiology of COPD (COPDGene) cohort (n = 2,580). Participants were current and former smokers with > 10 pack-years of tobacco exposure. Data from the two cohorts were analyzed separately because of methodologic differences. Lung hyperinflation was assessed by plethysmography in the SCCOR cohort and by inspiratory and expiratory CT scan lung volumes in the COPDGene cohort. Subclinical CAD was assessed as the coronary artery calcium score, whereas clinical CAD was defined as a self-reported history of CAD or myocardial infarction (MI). Analyses were performed in all smokers and then repeated in those with airflow obstruction (FEV(1) to FVC ratio, < 0.70). RESULTS: Pulmonary phenotypes, including airflow limitation, emphysema, lung hyperinflation, diffusion capacity, and radiographic measures of airway remodeling, showed weak to moderate correlations (r < 0.7) with each other. In multivariate models adjusted for pulmonary phenotypes and CAD risk factors, lung hyperinflation was the only phenotype associated with calcium score, history of clinical CAD, or history of MI (per 0.2 higher expiratory and inspiratory CT scan lung volume; coronary calcium: OR, 1.2; 95% CI, 1.1-1.5; P = .02; clinical CAD: OR, 1.6; 95% CI, 1.1-2.3; P = .01; and MI in COPDGene: OR, 1.7; 95% CI, 1.0-2.8; P = .05). FEV(1) and emphysema were associated with increased risk of CAD (P < .05) in models adjusted for CAD risk factors; however, these associations were attenuated on adjusting for lung hyperinflation. Results were the same in those with airflow obstruction and were present in both cohorts. INTERPRETATION: Lung hyperinflation is associated strongly with clinical and subclinical CAD in smokers, including those with airflow obstruction. After lung hyperinflation was accounted for, FEV(1) and emphysema no longer were associated with CAD. Subsequent studies should consider measuring lung hyperinflation and examining its mechanistic role in CAD in current and former smokers.

The Stable Marriage Problem (SMP) is concerned with the follow scenario: suppose we have two disjoint sets of agents—for example prospective students and colleges, medical residents and hospitals, or potential romantic partners—who wish to be matched into pairs. Each agent has preferences in the form of a ranking of her potential matches. How should we match agents based on their preferences?We say that a matching is "stable" if no unmatched pair of agents mutually prefer each other to their assigned partners. In their seminal work on the SMP, Gale and Shapley prove that a stable matching exists for any preferences. They further describe an efficient algorithm for finding a stable matching. In this dissertation, we consider the computational complexity of the SMP in the distributed setting, and the complexity of finding “almost stable” matchings. Highlights include (1) communication lower bounds for finding stable and almost stable matchings, (2) a distributed algorithm which finds an almost stable matching in poly-logarithmic time, and (3) hardness of approximation results for three dimensional analogues of the SMP.

RATIONALE: Multiple studies have demonstrated an increased risk of chronic obstructive pulmonary disease (COPD) in heterozygous carriers of the AAT (alpha-1 antitrypsin) Z allele. However, it is not known if MZ subjects with COPD are phenotypically different from noncarriers (MM genotype) with COPD. OBJECTIVES: To assess if MZ subjects with COPD have different clinical features compared with MM subjects with COPD. METHODS: Genotypes of SERPINA1 were ascertained by using whole-genome sequencing data in three independent studies. We compared outcomes between MM subjects with COPD and MZ subjects with COPD in each study and combined the results in a meta-analysis. We performed longitudinal and survival analyses to compare outcomes in MM and MZ subjects with COPD over time. MEASUREMENTS AND MAIN RESULTS: We included 290 MZ subjects with COPD and 6,184 MM subjects with COPD across the three studies. MZ subjects had a lower FEV(1)% predicted and greater quantitative emphysema on chest computed tomography scans compared with MM subjects. In a meta-analysis, the FEV(1) was 3.9% lower (95% confidence interval [CI], −6.55% to −1.26%) and emphysema (the percentage of lung attenuation areas

The accumulation of pro-inflammatory macrophages in the inflamed vascular wall is a critical step in atherogenesis. The mechanism of macrophage retention within the site of inflammation is not understood yet. High adhesion that prevents macrophage migration is one of the potential mechanisms. We previously showed that integrin α D β 2 is upregulated on pro-inflammatory macrophages, promotes macrophage retention, and contributes to atherogenesis. However, we have not identified a key ligand for α D β 2 within the tissue, since α D β 2 does not interact with major ECM proteins, collagens, and laminins. We recently found that during acute inflammation, the oxidation of docosahexaenoic acid (DHA) leads to the generation of end product carboxyethylpyrrole (CEP), which forms an adduct with fibrinogen and albumin via ε-amino group of lysines. Moreover, we revealed that macrophages adhered to CEP-modified albumin in α D β 2 -dependent manner. Now we are testing a hypothesis that DHA oxidation is a universal mechanism during chronic inflammatory diseases that promotes the generation of CEP adducts with different ECM proteins and forms α D β 2 -mediated strong anchorage of macrophages, which is critical for macrophage retention during chronic inflammation. We detected CEP-modified proteins in digested atherosclerotic lesions by western blot. In vitro DHA oxidation leads to the formation of CEP adducts with collagen IV and laminin but not with collagen I. Using α D β 2 -transfected HEK293 cells, WT and α D -/- mouse macrophages, we revealed that CEP-modified proteins support stronger cell adhesion and spreading to compare with natural macrophage ligands. Using site-directed mutagenesis, we generated mutant α D I-domains and α D β 2 -transfected cells with single amino acid substitutions. Applying protein-protein binding and adhesion assays we detected one amino acid within integrin α D , K 246 , which is critical for α D β 2 binding to CEP-modified proteins. In summary, we propose a new mechanism of macrophage retention, which is based on inflammatory modifications of ECM with DHA end-product, CEP. The identification of a binding site for CEP-modified proteins within α D β 2 will help to develop a blocking reagent for the treatment of the inflammatory component of atherosclerosis.

To evaluate the clinical efficacy and patient satisfaction rates of low-intensity extracorporeal shockwave therapy LIESWT) in men with vasculogenic erectile dysfunction (ED) using Duolith SD1 machine.This prospective, randomized, double-blinded clinical trial included 60 men who were randomly assigned to LIESWT (n=30, active group) or placebo (n=30) over 6 weeks. Patient demographics, change in International Index of Erectile Function (IIEF)-5, Erection Hardness Score (EHS) and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) scores, and an overall satisfaction score (on a 5-point scale), were recorded. All patients were reviewed at 1, 3, and 6 months after completion of therapy.There were 21 (70%) patients in the LIESWT group and 3 (10%) patients in the placebo group who had a 5-point or greater increase in IIEF-5 score (p=0.018). At 6-month study period, the mean IIEF-5 score was 18.8 (standard deviation [SD], 3.8) in the LIESWT group versus 14.8 (SD, 3.6) in the placebo group, difference in means between groups was 4.0 (95% confidence interval, 2.1-5.9; p0.001). The EHS scores were higher in the LIESWT group with a mean of greater than 1.2 across the 1, 3, and 6 months compared to the placebo group (p0.05). All patients completed the treatment study and there was no adverse event reported in terms of penile pain, bruising or deformity. There was a positive correlation between men who reported improvement in EF and treatment satisfaction level with LiESWT (p=0.008).LIESWT improves erectile function in the short-term especially in men with mild to moderate ED, and those without a cardiometabolic disease.

Rationale: Increasing awareness of the prevalence and significance of Preserved Ratio Impaired Spirometry (PRISm), alternatively known as restrictive or Global Initiative for Chronic Obstructive Lu...

Animal cruelty cases can involve a variety of mistreatment to domestic animals. A common source of abuse is the use of heat sources, such as ovens, hot surfaces and microwaves. Analysis of damage to skin by a veterinarian is a key aspect of these investigations but additional information can be provided by observing the hair of the animal, including heat source type and exposure time. This study developed an objective grading system for the analysis of heat damage in hairs which can be used to quantify different damage characteristics including bubbling, discolouration, expansion of hair, fractures, changes to the medulla and scales and scale removal/melting. This grading scheme was applied to the investigation of dog (Canis familiaris) skin samples with full pelage and loose hairs exposed to microwaves and a heated environment in order to identify any distinguishing damage characteristics from the two different heated environments. Samples were exposed to a furnace for 1 min at different temperature ranges (50–350 °C with 50 °C intervals) and also a microwave at maximum power for different time periods (15, 30, 45, 60, 120, 180, 240 and 300 s). Hairs were extracted for examination using high powered light microscopy and scanning electron microscopy. Overall, it can be determined that the type of damage observed is influenced by the nature of heat applied and the context and substrate in which the hair is situated at the time of exposure. Using principal component analysis (PCA) it was concluded that as temperature increases in a furnace so does the severity of each of the damage characteristics observed. It can be noted that with furnace exposure, any one of the characteristics could be used to indicate the temperature to which it has been exposed. For furnace exposed samples there was no significant difference between loose or embedded hairs. PCA analysis determined that there are two independent forms of damage that occur when hairs are exposed to microwave radiation, these are: increased bubbling and discolouration in the root and increased bubbling and discolouration of the shaft and tip. Exposure time is correlated with both the root and shaft/tip observations. The results indicated some clear distinctions between heat source and exposure useful for the objective interpretation of such evidence. This standardised approach for the observation of heat damage characteristics in animal hair provides investigators with a tool to differentiate between methods of abuse, providing a greater understanding of the crime committed.

Contains fulltext : 194255.pdf (Publisher’s version ) (Open Access) BACKGROUND: Emphysema has considerable variability in its regional distribution. Craniocaudal emphysema distribution is an important predictor of the response to lung volume reduction. However, there is little consensus regarding how to define upper lobe-predominant and lower lobe-predominant emphysema subtypes. Consequently, the clinical and genetic associations with these subtypes are poorly characterized. METHODS: We sought to identify subgroups characterized by upper-lobe or lower-lobe emphysema predominance and comparable amounts of total emphysema by analyzing data from 9,210 smokers without alpha-1-antitrypsin deficiency in the Genetic Epidemiology of COPD (COPDGene) cohort. CT densitometric emphysema was measured in each lung lobe. Random forest clustering was applied to lobar emphysema variables after regressing out the effects of total emphysema. Clusters were tested for association with clinical and imaging outcomes at baseline and at 5-year follow-up. Their associations with genetic variants were also compared. RESULTS: Three clusters were identified: minimal emphysema (n = 1,312), upper lobe-predominant emphysema (n = 905), and lower lobe-predominant emphysema (n = 796). Despite a similar amount of total emphysema, the lower-lobe group had more severe airflow obstruction at baseline and higher rates of metabolic syndrome compared with subjects with upper-lobe predominance. The group with upper-lobe predominance had greater 5-year progression of emphysema, gas trapping, and dyspnea. Differential associations with known COPD genetic risk variants were noted. CONCLUSIONS: Subgroups of smokers defined by upper-lobe or lower-lobe emphysema predominance exhibit different functional and radiological disease progression rates, and the upper-lobe predominant subtype shows evidence of association with known COPD genetic risk variants. These subgroups may be useful in the development of personalized treatments for COPD.

A critical step in the development of chronic inflammatory diseases is the accumulation of proinflammatory macrophages in the extracellular matrix (ECM) of peripheral tissues. The adhesion receptor integrin α(D)β(2) promotes the development of atherosclerosis and diabetes by supporting macrophage retention in inflamed tissue. We recently found that the end product of docosahexaenoic acid (DHA) oxidation, 2-(ω-carboxyethyl)pyrrole (CEP), serves as a ligand for α(D)β(2). CEP adduct with ECM is generated during inflammation-mediated lipid peroxidation. The goal of this project was to identify a specific inhibitor for α(D)β(2)–CEP interaction that can prevent macrophage accumulation. Using a specially designed peptide library, Biacore-detected protein–protein interaction, and adhesion of integrin-transfected HEK 293 cells, we identified a sequence (called P5 peptide) that significantly and specifically inhibited α(D)–CEP binding. In the model of thioglycollate-induced peritoneal inflammation, the injection of cyclic P5 peptide reduced 3-fold the macrophage accumulation in WT mice but had no effect in α(D)-deficient mice. The tracking of adoptively transferred, fluorescently labeled WT and α(D)(−/−) monocytes in the model of peritoneal inflammation and in vitro two-dimensional and three-dimensional migration assays demonstrated that P5 peptide does not affect monocyte transendothelial migration or macrophage efflux from the peritoneal cavity but regulates macrophage migration through the ECM. Moreover, the injection of P5 peptide into WT mice on a high-fat diet prevents macrophage accumulation in adipose tissue in an α(D)β(2)-dependent manner. Taken together, these results demonstrate the importance of α(D)β(2)-mediated macrophage adhesion for the accumulation of infiltrating macrophages in the inflamed ECM and propose P5 peptide as a potential inhibitor of atherogenesis and diabetes.

Rationale: The American Thoracic Society (ATS)/European Respiratory Society defines a positive bronchodilator response (BDR) by a composite of BDR in either forced expiratory volume in 1 second (FEV(1)) and/or forced vital capacity (FVC) greater than or equal to 12% and 200 ml (ATS-BDR). We hypothesized that ATS-BDR components would be differentially associated with important chronic obstructive pulmonary disease (COPD) outcomes. Objectives: To examine whether ATS-BDR components are differentially associated with clinical, functional, and radiographic features in COPD. Methods: We included subjects with COPD enrolled in the COPDGene study. In the main analysis, we excluded subjects with self-reported asthma. We categorized BDR into the following: 1) No-BDR, no BDR in either FEV(1) or FVC; 2) FEV(1)-BDR, BDR in FEV(1) but no BDR in FVC; 3) FVC-BDR, BDR in FVC but no BDR in FEV(1); and 4) Combined-BDR, BDR in both FEV(1) and FVC. We constructed multivariable logistic, linear, zero-inflated negative binomial, and Cox hazards models to examine the association of BDR categories with symptoms, computed tomography findings, change in FEV(1) over time, respiratory exacerbations, and mortality. We also created models using the ATS BDR definition (ATS-BDR) as the main independent variable. Results: Of 3,340 COPD subjects included in the analysis, 1,083 (32.43%) had ATS-BDR, 182 (5.45%) had FEV(1)-BDR, 522 (15.63%) had FVC-BDR, and 379 (11.34%) had Combined-BDR. All BDR categories were associated with FEV(1) decline compared with No-BDR. Compared with No-BDR, both ATS-BDR and Combined-BDR were associated with higher functional residual capacity %predicted, greater internal perimeter of 10 mm, and greater 6-minute-walk distance. In contrast to ATS-BDR, Combined-BDR was independently associated with less emphysema (adjusted beta regression coefficient, −1.67; 95% confidence interval [CI], −2.68 to −0.65; P = 0.001), more frequent respiratory exacerbations (incidence rate ratio, 1.25; 95% CI, 1.03–1.50; P = 0.02) and severe exacerbations (incidence rate ratio, 1.34; 95% CI, 1.05–1.71; P = 0.02), and lower mortality (adjusted hazards ratio, 0.76; 95% CI, 0.58–0.99; P = 0.046). Sensitivity analysis that included subjects with self-reported history of asthma showed similar findings. Conclusions: BDR in both FEV(1) and FVC indicates a COPD phenotype with asthma-like characteristics, and provides clinically more meaningful information than current definitions of BDR.

Background Chronic bronchitis (CB) increases risk of COPD exacerbations. We have shown that the St. George's Respiratory Questionnaire (SGRQ) CB definition identifies patients with a similar clinical phenotype as classically defined CB. Whether the SGRQ CB definition is a predictor of future COPD exacerbations is unknown. Methods We analyzed 7,557 smokers with normal spirometry and Global Initiative for Chronic Obstructive Lung Disease stage 1-4 COPD in the Genetic Epidemiology of COPD study with longitudinal follow-up data on exacerbations. Subjects were divided into classic CB+ or classic CB–, using the classic definition. In addition, subjects were divided into SGRQ CB+ or SGRQ CB–. Exacerbation frequency and severe exacerbation frequency were determined in each group. Multivariable linear regressions were performed for exacerbation frequency with either classic CB or SGRQ CB and relevant covariates. Results There were 1,434 classic CB+ subjects and 2,290 SGRQ CB+ subjects. The classic CB+ group had a greater exacerbation frequency compared with the classic CB– group (0.69 ± 1.26 vs 0.36 ± 0.90 exacerbations per patient per year; P Conclusions The SGRQ CB definition identified more subjects at risk for future exacerbations than the classic CB definition. SGRQ CB was at least a similar if not better predictor of future exacerbations than classic CB.

In the absence of mitigation measures, the ongoing effort to deepen the navigation channel in Georgia’s Port of Savannah would reduce dissolved oxygen levels in the Savannah River below what is needed to sustain ecological diversity. To prevent this scenario, a series of oxygen-injection cones will be installed in two locations to add 40,000 lb of dissolved oxygen per day to the waterway.

Spirometric Volumes and Breathlessness Across Levels of Airflow Limitation : The COPDGene Study.

BACKGROUND:Eosinophilic airway inflammation in patients with chronic obstructive pulmonary disease (COPD) is associated with exacerbations and responsivity to steroids, suggesting potential shared mechanisms with eosinophilic asthma. However, there is no consistent blood eosinophil count that has been used to define the increased exacerbation risk. OBJECTIVE:We sought to investigate blood eosinophil counts associated with exacerbation risk in patients with COPD. METHODS:Blood eosinophil counts and exacerbation risk were analyzed in patients with moderate-to-severe COPD by using 2 independent studies of former and current smokers with longitudinal data. The Genetic Epidemiology of COPD (COPDGene) study was analyzed for discovery (n=1,553), and the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study was analyzed for validation (n=1,895). Asubset of the ECLIPSE study subjects were used to assess the stability of blood eosinophil counts over time. RESULTS:COPD exacerbation risk increased with higher eosinophil counts. An eosinophil count threshold of 300cells/μL or greater showed adjusted incidence rate ratios for exacerbations of 1.32 in the COPDGene study (95% CI, 1.10-1.63). The cutoff of 300cells/μL or greater was validated for prospective risk of exacerbation in the ECLIPSE study, with adjusted incidence rate ratios of 1.22 (95% CI, 1.06-1.41) using 3-year follow-up data. Stratified analysis confirmed that the increased exacerbation risk associated with an eosinophil count of 300cells/μL or greater was driven by subjects with a history of frequent exacerbations in both the COPDGene and ECLIPSE studies. CONCLUSIONS:Patients with moderate-to-severe COPD and blood eosinophil counts of 300cells/μL or greater had an increased risk exacerbations in the COPDGene study, which was prospectively validated in the ECLIPSE study.

The heritability of chronic obstructive pulmonary disease (COPD) cannot be fully explained by recognized genetic risk factors identified as achieving genome-wide significance. In addition, the combined contribution of genetic variation to COPD risk has not been fully explored. We sought to determine: (1) whether studies of variants from previous studies of COPD or lung function in a larger sample could identify additional associated variants, particularly for severe COPD; and (2) the impact of genetic risk scores on COPD. We genotyped 3,346 single-nucleotide polymorphisms (SNPs) in 2,588 cases (1,803 severe COPD) and 1,782 control subjects from four cohorts, and performed association testing with COPD, combining these results with existing genotyping data from 6,633 cases (3,497 severe COPD) and 5,704 control subjects. In addition, we developed genetic risk scores from SNPs associated with lung function and COPD and tested their discriminatory power for COPD-related measures. We identified significant associations between SNPs near PPIC (P = 1.28 X 10(-8)) and PPP4R4/SERPINA1 (P = 1.01 X 10(-8)) and severe COPD; the latter association may be driven by recognized variants in SERPINA1. Genetic risk scores based on SNPs previously associated with COPD and lung function had a modest ability to discriminate COPD (area under the curve, similar to 0.6), and accounted for a mean 0.9-1.9% lower forced expiratory volume in 1 second percent predicted for each additional risk allele. In a large genetic association analysis, we identified associations with severe COPD near PPIC and SERPINA1. A risk score based on combining genetic variants had modest, but significant, effects on risk of COPD and lung function.

Chronic obstructive pulmonary disease (COPD) is a condition in which continuous bronchodilation may have clinical advantages. This study evaluated salmeterol, a beta-agonist bronchodilator with a duration of action substantially longer than that of short-acting beta-agonists, compared with ipratropium, an anticholinergic bronchodilator, and placebo in patients with COPD. Four hundred and five patients with COPD received either salmeterol 42 microg twice daily, ipratropium bromide 36 microg four times daily, or placebo for 12 wk in this randomized, double-blind, parallel-group study. Patients were stratified on the basis of bronchodilator response to albuterol (12% and200-ml improvement) and were randomized within each stratum. Bronchodilator response was measured over 12 h four times during the treatment period. Salmeterol provided similar maximal bronchodilatation to ipratropium but had a longer duration of action and a more constant bronchodilatory effect with no evidence of bronchodilator tolerance. Both active treatments were well tolerated. Salmeterol was an effective bronchodilator with a consistent effect over this 12-wk study in patients with COPD, including those "unresponsive" to albuterol. The long duration of action of salmeterol offers the advantage of twice daily dosing compared with the required four times a day dosing with ipratropium.

Background —Electrical storm (ES), defined as recurrent multiple ventricular fibrillation (VF) episodes, often occurs in patients with recent myocardial infarction. Because treating ES according to the Advanced Cardiac Life Support (ACLS) guidelines yields a poor outcome, we evaluated the efficacy of sympathetic blockade in treating ES patients and compared their outcome with that of patients treated according to the ACLS guidelines. Methods and Results —Forty-nine patients (36 men, 13 women, mean age 57±10 years) who had ES associated with a recent myocardial infarction were separated into 2 groups. Patients in group 1 (n=27) received sympathetic blockade treatment: 6 left stellate ganglionic blockade, 7 esmolol, and 14 propranolol. Patients in group 2 (n=22) received antiarrhythmic medication as recommended by the ACLS guidelines. Patient characteristics were similar in the 2 groups. The 1-week mortality rate was higher in group 2: 18 (82%) of the 22 patients died, all of refractory VF; 6 (22%) of the 27 group 1 patients died, 3 of refractory VF ( P P Conclusions —Sympathetic blockade is superior to the antiarrhythmic therapy recommended by the ACLS guidelines in treating ES patients. Our study emphasizes the role of increased sympathetic activity in the genesis of ES. Sympathetic blockade−not class 1 antiarrhythmic drugs−should be the treatment of choice for ES.

Objective— Abdominal aortic aneurysms (AAAs) and heart failure are complex life-threatening diseases whose etiology is not completely understood. We recently reported that deficiency of group X secretory phospholipase A2 (GX sPLA2) reduces abdominal aortic aneurysm (AAA) formation in apoE -/- mice infused with angiotensin II. In this study, we investigated whether deficiency of a related enzyme, GV sPLA2, also protects mice from experimental AAA. The impact of GV sPLA2 deficiency on Ang II-induced cardiac fibrosis was also assessed. Methods and results— ApoE -/- mice and apoE -/- mice lacking GV sPLA2 (GV DKO) were infused with 1000 ng/kg/min Ang II for up to 28 days. Increases in systolic blood pressure, urinary prostanoids, and plasma aldosterone were similar in apoE -/- and GV DKO mice after Ang II infusion. The incidence of aortic rupture in Ang II-infused GV DKO mice (10%) was significantly lower compared to apoE -/- mice (30%). Although the overall incidence of AAA in GV DKO mice (∼81.25%) and apoE -/- mice (100%) was similar, the mean percent increase in maximal luminal diameter of abdominal aortas was significantly smaller in GV DKO mice (68.5±7.7%) compared to apoE -/- mice (92.6±8.3%). Deficiency of GV sPLA2 resulted in increased Ang II-induced cardiac fibrosis that was most pronounced in perivascular regions. Perivascular collagen, visualized by picrosirius red staining, was associated with increased TUNEL staining and increased immunopositivity for macrophage and myofibroblast cells and NOX-2 and NOX-4. Conclusion— Our findings indicate that GV sPLA2 modulates pathological responses to Ang II, with different outcomes for AAA and cardiac fibrosis. These data have important implications for sPLA2 inhibitors that are currently being developed for clinical use.

Background: Group X secretory phospholipase A2 (GX sPLA2) potently releases arachidonic acid (AA) from the plasma membrane of intact cells. AA is a precursor of bioactive prostaglandins that are known to modulate insulin secretion by β-islet cells. C57BL/6 mice deficient in GX sPLA2 (GX KO) are protected from age-related defect in glucose tolerance. GX sPLA2 is expressed in mouse pancreatic islet cells. In this study we tested the hypothesis that GX sPLA2 regulates pancreatic insulin secretion. Methods and results: Glucose stimulated insulin secretion (GSIS) was measured in vivo in WT and GX KO mice and ex vivo using pancreatic islet cells isolated from WT and GX KO mice. To complement these studies, GSIS was also assessed in vitro using Min6 pancreatic beta cell lines with or without GX sPLA2 overexpression. GSIS was significantly increased in GX KO mice compared to WT mice, and in islet cells isolated from GX KO mice compared to WT mice. Consistent with this finding, Min6 cells overexpressing GX sPLA2 demonstrated significantly decreased GSIS compared to control cells. Expression of ABCA1 and ABCG1 mRNAs were significantly upregulated in islet cells from GX KO mice compared to WT mice, consistent with our previous report that GX sPLA2 negatively regulates LXR activity. However, there was no significant difference in cholesterol content between islets from WT and GX KO mice suggesting that altered LXR activity may not be the mechanism. Min6 cells overexpressing GX sPLA2 secrete significantly increased levels of PGE2- a known negative regulator of GSIS, in the medium compared to control cells. Treatment of these cells with NS398- an inhibitor of COX2 enzyme, abolished the decrease in GSIS shown by these cells. Conclusions: We conclude that GX sPLA2 plays a previously unrecognized role in negatively regulating pancreatic insulin secretion most likely by enhancing PGE2 production.

The effects of moderate, chronic (5 days) potassium depletion on cardiac function were assessed in 14 normokalemic and 13 hypokalemic open chest, anesthetized dogs. Cardiac responses to intravenous bolus injection of 2.5 micrograms/kg body weight epinephrine (10 normokalemic and 11 hypokalemic dogs) and to rapidly increased preload (8 dogs in each group) were evaluated. Hypokalemic dogs received a low potassium diet plus chlorthalidone. Plasma potassium levels were lower (p less than 0.001) in the hypokalemic dogs (3.2 +/- 0.1 mEq/liter [mean +/- SEM]) than in the normokalemic dogs (4.1 +/- 0.1). The inotropic response to epinephrine was lower in hypokalemic than in normokalemic dogs, the response of the maximal rate of rise of left ventricular pressure was 20% greater (p less than 0.03) and the response of the peak rate of change of ejection power was 60% greater in the normokalemic dogs. The relaxation response to epinephrine (the maximal rate of fall of left ventricular pressure) was 33% lower (p less than 0.02) in hypokalemic dogs. Responses to rapid volume expansion were impaired by hypokalemia; maximal stroke volume index was 31% lower (p less than 0.01), maximal cardiac index was 26% lower (p less than 0.01) and the peak response to the maximal rate of filling was 51% lower (p less than 0.01). There were no differences in basal cardiac function. Therefore, modest potassium depletion within the clinical range impaired the contractile and relaxation responses to epinephrine and preload and impaired rapid filling.

Exhaled breath analysis holds great promise as a diagnostic and investigative tool in COPD and is a new and rapidly expanding field of research in pulmonary disease. Generally speaking, exhaled breath analysis focuses on two areas: measurement of exhaled nitric oxide (ENO) and the detection of biomarkers in exhaled breath condensate (EBC). ENO measurement may not be as useful in COPD as in other pulmonary diseases, such as asthma, due to the lower levels of ENO found in COPD, although this is an area of ongoing research. Analysis of EBC for proinflammatory biomarkers is an area of great promise but its true value will not be realized until methods of collecting and analyzing EBC have been standardized. Once this is done, biomarkers detected in EBC may assist in the diagnosis of COPD, identification of preclinical disease, phenotyping of COPD patients, evaluation of response to therapies and defining the prognosis of individual patients. Identification of novel inflammatory mediators in EBC may cast new light on the pathogenesis of COPD and identify new therapeutic targets, which are badly needed in this disease.

Introduction: Group X secretory phospholipase A 2 (GX sPLA 2 ) has been implicated in a number of important biological processes, some of which appear to be independent of its lipolytic activity. These effects of GX sPLA 2 may be in part due to its high affinity binding to the M-type sPLA 2 receptor. To elucidate the physiological functions of this enzyme in vivo , we recently developed C57BL/6 mice with targeted deletion of GX sPLA 2 (GX KO mice). Results : Unexpectedly, GX KO mice have ~50% higher plasma corticosterone level compared to wild-type (WT) mice. Real-time RT-PCR and immunoblot analyses showed that expression of Steroidogenic Acute Regulatory Protein (StAR), a rate limiting protein in steroid production, is 2–5-fold higher in adrenals of GX KO mice compared to WT mice. GX KO mice responded normally to dexamethasone, indicating no impairment of the hypothalamic-pituitary axis. To provide additional evidence for a direct effect of Group X sPLA 2 on adrenal corticosteroid production, we performed studies in mouse adrenocortical tumor (Y-1) cells, which endogenously express GX sPLA 2 and the M-type receptor. Over-expression of GX sPLA 2 , or incubations with GX sPLA 2 , resulted in a significant reduction in progesterone production and StAR expression in Y-1 cells. Indoxam, an inhibitor of GX sPLA 2 activity and potent blocker of sPLA 2 binding to the M-type receptor, resulted in a significant increase in progesterone production and StAR expression in both control and GX sPLA 2 -overexpressing cells. Because several studies have implicated the extracellular signal-regulated kinase (ERK) cascade in the regulation of steroidogenesis, we investigated whether GX sPLA 2 altered adrenal ERK1/2 activation. Over-expression of GX sPLA 2 in Y-1 cells resulted in significantly increased ERK1/2 phosphorylation, whereas deficiency of GX sPLA 2 was accompanied by a significant decrease in phosphorylated ERK1/2 in mouse adrenals. Conclusions: We provide the novel finding that GX sPLA 2 has a direct effect on adrenal cells to regulate glucocorticoid production. Our in vivo and in vitro data indicate that Group X sPLA 2 down-regulates the expression of StAR, possibly through M-type receptor-mediated activation of ERK1/2.

Introduction: Of the 10 secretory phospholipase A 2 (sPLA 2 ) enzymes expressed in humans, Group X (GX) sPLA 2 is the most potent in hydrolyzing phospholipids on cell membranes. In addition to its lipolytic activity, GX sPLA 2 is also a high affinity ligand for the M-type sPLA 2 receptor. Although numerous studies have implicated GX sPLA 2 in important biological processes in vitro , data from studies in vivo are lacking. To elucidate the physiological functions of this enzyme we recently developed C57BL/6 mice with targeted deletion of the GX sPLA 2 gene. Results : Analysis by real time RT-PCR showed that GX sPLA 2 mRNA is widely distributed in mouse tissues, with highest expression in intestine, testes, brain, thymus, spleen, fat, lung, and heart. Unlike some of the other members of the sPLA 2 family, tissue expression of GX sPLA 2 was not highly upregulated in mice injected with lipopolysaccharide. However, GX sPLA 2 was induced almost 5-fold in retroperitoneal fat of mice fed a high-fat (60 kcal%) diet for 17 weeks.Targeted disruption of GX sPLA 2 resulted in increased body weight in 1.5 year-old mice fed a normal laboratory diet (male GX sPLA 2 +/+ mice: 35.8±0.4 g; male GX sPLA 2 −/− mice: 45.033.2 g; p2 +/+ mice: 16.0±1.0%; GX sPLA 2 −/− mice: 19.6±1%; p2 +/+ mice: 1300±26 um 2 GX sPLA 2 −/− mice: 2700±78 um 2 ; p2 +/+ mice: 46.3±4.9 mg/dl; GX sPLA 2 −/− mice: 33.8±2.9 mg/dl; p2 −/− and GX sPLA 2 +/+ mice. Compared to 3 month old GX sPLA 2 +/+ mice, the relative expression of IL-6 and F4/80 mRNAs in adipose tissue of age-matched GX sPLA 2 −/− mice was increased 9- and 4-fold, respectively, suggesting that the increased adiposity in GX sPLA 2 −/− mice was associated with an increase in the inflammatory profile of adipose tissue Conclusions: Our data points to a previously unrecognized role for Group X sPLA 2 in the development of obesity and associated adipose tissue inflammation.