Effects of Exendin-4 on human adipose tissue inflammation and ECM remodelling

Subjects with type-2 diabetes are typically obese with dysfunctional adipose tissue (AT). Glucagon-like peptide-1 (GLP-1) analogues are routinely used to improve glycaemia. Although, they also aid weight loss that improves AT function, their direct effect on AT function is unclear. To explore GLP-1 analogues’ influence on human AT’s cytokine and extracellular matrix (ECM) regulation, we therefore obtained and treated omental (OMAT) and subcutaneous (SCAT) AT samples with Exendin-4, an agonist of the GLP-1 receptor (GLP-1R)Final publishe

Discordant identification of pediatric severe sepsis by research and clinical definitions in the SPROUT international point prevalence study

Introduction: Consensus criteria for pediatric severe sepsis have standardized enrollment for research studies. However, the extent to which critically ill children identified by consensus criteria reflect physician diagnosis of severe sepsis, which underlies external validity for pediatric sepsis research, is not known. We sought to determine the agreement between physician diagnosis and consensus criteria to identify pediatric patients with severe sepsis across a network of international pediatric intensive care units (PICUs). Methods: We conducted a point prevalence study involving 128 PICUs in 26 countries across 6 continents. Over the course of 5 study days, 6925 PICU patients <18 years of age were screened, and 706 with severe sepsis defined either by physician diagnosis or on the basis of 2005 International Pediatric Sepsis Consensus Conference consensus criteria were enrolled. The primary endpoint was agreement of pediatric severe sepsis between physician diagnosis and consensus criteria as measured using Cohen's ?. Secondary endpoints included characteristics and clinical outcomes for patients identified using physician diagnosis versus consensus criteria. Results: Of the 706 patients, 301 (42.6 %) met both definitions. The inter-rater agreement (? ± SE) between physician diagnosis and consensus criteria was 0.57 ± 0.02. Of the 438 patients with a physician's diagnosis of severe sepsis, only 69 % (301 of 438) would have been eligible to participate in a clinical trial of pediatric severe sepsis that enrolled patients based on consensus criteria. Patients with physician-diagnosed severe sepsis who did not meet consensus criteria were younger and had lower severity of illness and lower PICU mortality than those meeting consensus criteria or both definitions. After controlling for age, severity of illness, number of comorbid conditions, and treatment in developed versus resource-limited regions, patients identified with severe sepsis by physician diagnosis alone or by consensus criteria alone did not have PICU mortality significantly different from that of patients identified by both physician diagnosis and consensus criteria. Conclusions: Physician diagnosis of pediatric severe sepsis achieved only moderate agreement with consensus criteria, with physicians diagnosing severe sepsis more broadly. Consequently, the results of a research study based on consensus criteria may have limited generalizability to nearly one-third of PICU patients diagnosed with severe sepsis

Clinical significance of troponin elevations in acute decompensated diabetes without clinical acute coronary syndrome

<p>Abstract</p> <p>Background</p> <p>Elevation of cardiac troponin has been documented in multiple settings without acute coronary syndrome. However, its impact on long-term cardiac outcomes in the context of acute decompensated diabetes remains to be explored.</p> <p>Methods</p> <p>We performed a retrospective analysis of 872 patients admitted to Temple University Hospital from 2004–2009 with DKA or HHS. Patients were included if they had cardiac troponin I (cTnI) measured within 24 hours of hospital admission, had no evidence of acute coronary syndrome and had a follow up period of at least 18 months. Of the 264 patients who met the criteria, we reviewed the baseline patient characteristics, admission labs, EKGs and major adverse cardiovascular events during the follow up period. Patients were categorized into two groups with normal and elevated levels of cardiac enzymes. The composite end point of the study was the occurrence of a major cardiovascular event (MACE) during the follow up period and was compared between the two groups.</p> <p>Results</p> <p>Of 264 patients, 24 patients were found to have elevated cTnI. Compared to patients with normal cardiac enzymes, there was a significant increase in incidence of MACE in patients with elevated cTnI. In a regression analysis, which included prior history of CAD, HTN and ESRD, the only variable that independently predicted MACE was an elevation in cTnI (p = 0.044). Patients with elevated CK-MB had increased lengths of hospitalization compared to the other group (p < 0.001).</p> <p>Conclusions</p> <p>Elevated cardiac troponin I in patients admitted with decompensated diabetes and without evidence of acute coronary syndrome, strongly correlate with a later major cardiovascular event. Thus, elevated troponin I during metabolic abnormalities identify a group of patients at an increased risk for poor long-term outcomes. Whether these patients may benefit from early detection, risk stratification and preventive interventions remains to be investigated.</p

The mechanical properties of human adipose tissues and their relationships to the structure and composition of the extracellular matrix

Adipose tissue (AT) expansion in obesity is characterized by cellular growth and continuous extracellular matrix (ECM) remodeling with increased fibrillar collagen deposition. It is hypothesized that the matrix can inhibit cellular expansion and lipid storage. Therefore, it is important to fully characterize the ECM's biomechanical properties and its interactions with cells. In this study, we characterize and compare the mechanical properties of human subcutaneous and omental tissues, which have different physiological functions. AT was obtained from 44 subjects undergoing surgery. Force/extension and stress/relaxation data were obtained. The effects of osmotic challenge were measured to investigate the cellular contribution to tissue mechanics. Tissue structure and its response to tensile strain were determined using nonlinear microscopy. AT showed nonlinear stress/strain characteristics of up to a 30% strain. Comparing paired subcutaneous and omental samples (n = 19), the moduli were lower in subcutaneous: initial 1.6 ± 0.8 (means ± SD) and 2.9 ± 1.5 kPa (P = 0.001), final 11.7 ± 6.4 and 32 ± 15.6 kPa (P < 0.001), respectively. The energy dissipation density was lower in subcutaneous AT (n = 13): 0.1 ± 0.1 and 0.3 ± 0.2 kPa, respectively (P = 0.006). Stress/relaxation followed a two-exponential time course. When the incubation medium was exchanged for deionized water in specimens held at 30% strain, force decreased by 31%, and the final modulus increased significantly. Nonlinear microscopy revealed collagen and elastin networks in close proximity to adipocytes and a larger-scale network of larger fiber bundles. There was considerable microscale heterogeneity in the response to strain in both cells and matrix fibers. These results suggest that subcutaneous AT has greater capacity for expansion and recovery from mechanical deformation than omental AT

Surface deformation and reaction force estimation of liver tissue based on a novel nonlinear mass--spring--damper viscoelastic model

Rheological soft tissue models play an important role in designing control methods for modern teleoperation systems. In the meanwhile, these models are also essential for creating a realistic virtual environment for surgical training. The implementation of model-based control in teleoperation has been a frequently discussed topic in the past decades, offering solutions for the loss of stability caused by time delay, which is one of the major issues in long-distance force control. In this paper, mass–spring–damper soft tissue models are investigated, showing that the widely used linear models do not represent realistic behavior under surgical manipulations. A novel, nonlinear model is proposed, where mechanical parameters are estimated using curve fitting methods. Theoretical reaction force curves are estimated using the proposed model, and the results are verified using measurement results from uniaxial indentation. The model is extended with force estimation by nonuniform surface deformation, where the surface deformation function is approximated according to visual data. Results show that using the proposed nonlinear model, a good estimation of reaction force can be achieved within the range of 0–4 mm, provided that the tissue deformation shape function is appropriately approximated

Racial, Ethnic, and Socioeconomic Inequities in Access to Left Atrial Appendage Occlusion

Background Inequitable access to high‐technology therapeutics may perpetuate inequities in care. We examined the characteristics of US hospitals that did and did not establish left atrial appendage occlusion (LAAO) programs, the patient populations those hospitals served, and the associations between zip code–level racial, ethnic, and socioeconomic composition and rates of LAAO among Medicare beneficiaries living within large metropolitan areas with LAAO programs. Methods and Results We conducted cross‐sectional analyses of Medicare fee‐for‐service claims for beneficiaries aged 66 years or older between 2016 and 2019. We identified hospitals establishing LAAO programs during the study period. We used generalized linear mixed models to measure the association between zip code–level racial, ethnic, and socioeconomic composition and age‐adjusted rates of LAAO in the most populous 25 metropolitan areas with LAAO sites. During the study period, 507 candidate hospitals started LAAO programs, and 745 candidate hospitals did not. Most new LAAO programs opened in metropolitan areas (97.4%). Compared with non‐LAAO centers, LAAO centers treated patients with higher median household incomes (difference of $913 [95$197–$1629], P=0.01). Zip code–level rates of LAAO procedures per 100 000 Medicare beneficiaries in large metropolitan areas were 0.34$1000 zip code–level decrease in median household income. After adjustment for socioeconomic markers, age, and clinical comorbidities, LAAO rates were lower in zip codes with higher proportions of Black or Hispanic patients. Conclusions Growth in LAAO programs in the United States had been concentrated in metropolitan areas. LAAO centers treated wealthier patient populations in hospitals without LAAO programs. Within major metropolitan areas with LAAO programs, zip codes with higher proportions of Black and Hispanic patients and more patients experiencing socioeconomic disadvantage had lower age‐adjusted rates of LAAO. Thus, geographic proximity alone may not ensure equitable access to LAAO. Unequal access to LAAO may reflect disparities in referral patterns, rates of diagnosis, and preferences for using novel therapies experienced by racial and ethnic minority groups and patients experiencing socioeconomic disadvantage