Citations

Obesity is a persistent public health issue, often resulting in metabolic complications such as insulin resistance (IR). The secretion of pro-inflammatory cytokines from adipose tissue (AT) is increased during obesity, contributing to the impairment of systemic insulin sensitivity. While interventions in animal models have shown that reducing inflammation restores insulin sensitivity, human studies reducing systemic inflammation have produced inconsistent results. We recently demonstrated that three months of high-dose (4 g/daily) ω-3PUFA (fish oil, FO) supplementation improved insulin sensitivity, and decreased systemic and AT inflammation in individuals with obesity (BMI ≥ 30 kg/m2). Given recent studies highlighting the involvement of microRNA (miRNA) in inflammatory cytokine production, we investigated the effect of ω-3PUFA supplementation on AT miRNA expression in this cohort. AT biopsies were collected before and after ω-3PUFA supplementation. miRNA was processed on the Affymetrix miRNA 4.0 GeneChip and analyzed using existing inflammatory gene sets sourced from MSigDB. Unbiased, differentially expressed miRNA analysis identified miR-4498 and miR-5689 as significantly increased after three months of ω-3PUFA supplementation. Real-time PCR confirmed bioinformatic analysis findings. Our study reports the modulation of miRNA in AT, reductions in systemic and AT markers of inflammation, and the improvement of IR post ω-3PUFA supplementation. Further research is needed to elucidate the link between miR-4498, miR-5689, and whole-body insulin sensitivity.

BACKGROUND Obesity is a multifactorial disease with adverse health implications including insulin resistance (IR). In patients with obesity, the presence of high circulating levels of leptin, deemed hyperleptinemia, is associated with IR. Recent data in mice with diet-induced obesity (DIO) show that a partial reduction in leptin levels improves IR. Additional animal studies demonstrate that IL-4 decreases leptin levels. In rodents, resident adipose tissue eosinophils (AT-EOS) are the main source of IL-4 and are instrumental in maintaining metabolic homeostasis. A marked reduction in AT-EOS content is observed in animal models of DIO. These observations have not been explored in humans. METHODS We analyzed AT from individuals with obesity and age-matched lean counterparts for AT-EOS content, IL-4, circulating leptin levels, and measures of IR. RESULTS Our results show that individuals with obesity ( n = 15) had a significant reduction in AT-EOS content ( P < 0.01), decreased AT–IL-4 gene expression ( P = 0.02), and decreased IL-4 plasma levels ( P < 0.05) in addition to expected IR ( P < 0.001) and hyperleptinemia ( P < 0.01) compared with lean subjects ( n = 15). AT-EOS content inversely correlated with BMI ( P = 0.002) and IR ( P = 0.005). Ex vivo AT explants and in vitro cell culture of primary human mature adipocytes exposed to either IL-4 or EOS conditioned media produced less leptin ( P < 0.05). CONCLUSION Our results suggest that IL-4 acts as a link between EOS, AT, and leptin production. Future studies exploring this interaction may identify an avenue for the treatment of obesity and its complications through amelioration of hyperleptinemia. TRIAL REGISTRATION Clinicaltrials.gov NCT02378077 & NCT04234295.

Abstract Context. —Management of laboratories and pathology practices is increasingly complex. Residents and fellows in laboratory medicine and pathology need more structured curricula in leadership and management (L&M) training to function as medical and laboratory directors. Objective. —To define a curriculum that provides basic competency in L&M for residents and fellows in pathology. Design. —A year-long formal L&M course included didactic lectures, interactive sessions, case scenarios, team-building exercises, formal team presentations (capstone project), and precourse and postcourse assessment of L&M knowledge. The curriculum meets requirements of American College of Graduate Medical Education and supports goals for leadership training of the College of American Pathologists. Participants evaluated (5-point scale) the content and speakers of all sessions. Trainees were evaluated after considering postcourse examination results, quality of the capstone presentation, and a global assessment. Results. —The 5 non-capstone sessions received evaluation scores ranging from 4.4 (informatics) to 5 (L&M basics). Postcourse test scores showed significant improvement when compared with the pretest scores for the 2003– 2004 and 2004–2005 trainee cohorts. Conclusions. —Short-term results indicate that the course described improves trainee knowledge of L&M issues.

Abstract Context.—Managed care has changed the nature of medical practice. The practice of pathology has also changed and is likely to undergo further modification. Additional skills in leadership and management are needed to perform optimally in the current medical marketplace. Objective.—To determine whether pathologists view business and informatics skills as being important and valuable in their practices. Design.—A survey was sent electronically (via e-mail) to 2566 pathologists and pathology administrators. Results.—Two hundred sixteen survey recipients (8.4%) responded to the survey. The response rate to individual questions ranged from 86% to 99% (186 to 214 of 216 total respondents). Most who took the survey ranked communication (203/209; 97%), leadership skills (165/209; 79%), and systems thinking skills (155/209; 74%) as either “very important” or “essential.” Fewer respondents were willing to offer salary premiums for marketing (108/196; 55%), business or finance (92/196; 47%), or staff leadership (95/196; 48%) skills unless the candidate had a track record of measurable achievement using these skills. Those practicing in academia as well as those making hiring decisions by themselves were more likely to value leadership and management skills. Fewer than 1% of respondents in any category considered current pathology residency training in leadership and management to be adequate. Conclusions.—Prospective employers value leadership and management skills. Pathology residency programs must include meaningful training in pathology practice management and informatics to satisfy the demand for these skills in the modern pathology marketplace.

Abstract Objective. —To illustrate how laboratorians and pathologists must demonstrate accountability for efficiency (how well something is done), effectiveness (what is done), and cost-effectiveness (a proxy for value, in which value equals quality per cost). Data Sources. —A literature search was conducted, including documents in the National Library of Medicine. Study Selection. —The literature on cost-effectiveness of laboratory testing was reviewed. Conclusions. —The demand for proving the value of newer and more expensive medical technologies, including newer medical tests, will increase substantially. Payers, including Medicare, commercial insurers, and employers, will demand accountability and elimination of the abuse and misuse of ineffective testing strategies. Pathologists and laboratorians play a key role in guiding the most cost-effective use of testing strategies, including the judicious use of algorithms.

Abstract A novel role for adipose tissue (AT)-resident eosinophils (EOS) in metabolism has been suggested. These data were obtained using genetic animal models with either whole-body overexpression of Interleukin-5 (IL-5Tg) leading to eosinophilia or gene ablation resulting in complete lack of EOS. These models limit the specificity of the findings. We hypothesized that AT-resident EOS play a specific role in whole-body metabolism. To this end, we generated a transgenic mouse model overexpressing human eotaxin-2 (hE2) under the control of a fat-specific aP2 promoter, which would exclusively recruit circulating EOS into AT (hEo2Tg), without any changes in the overall EOS numbers. Compared with wild type (WT) mice, AT-EOS numbers were markedly increased in multiple fat depots from hEo2Tg mice, including subcutaneous white adipose tissue (sWAT). After 12 weeks of high-fat diet (HFD), hEo2Tg mice showed significantly less body weight gain and fat mass compared with WT littermates. These changes were associated with an improvement in glucose tolerance. We also found increased oxygen consumption and heat production in hEo2Tg mice under room temperature conditions. The increased thermogenesis was accompanied with an increased expression of browning genes such as Ucp1, Prdm16, Dio2 in sWAT from hEo2Tg HFD mice. So far, our data suggest that AT-resident EOS promote browning of sWAT. This, in turn, protects our animals against development of HFD-induced obesity and insulin resistance. Next, whole transcriptome mRNA sequencing and bioinformatic analyses were performed and showed a significant increase of myogenic differentiation 1 (Myod1) gene expression in hEo2Tg sWAT mice. This was confirmed by qRT-PCR. Myod1 is a key regulator of skeletal muscle differentiation. Given the shared features between brown fat and skeletal muscle, we speculate that by increasing Myod1 gene expression, (AT)-resident EOS mediate sWAT browning. Additional studies are needed to determine the molecular mechanism(s) underling the regulation of Myod1 gene expression by AT-resident EOS and its effect on sWAT browning.

Abstract Background Collecting a predefined set of blood tubes (the “rainbow draw”) is a common but controversial practice in many emergency departments (EDs), with limited data to support it. We determined the actual utilization of rainbow draw tubes at a single facility and evaluated the perceptions of ED staff regarding the utility of rainbow draws. Methods We analyzed 2 weeks of ED visits (1326 visits by 1240 unique patients) to determine blood tube utilization for initial and add-on testing, as well as the incidence of additional venipunctures. We also surveyed ED staff regarding aspects of ED phlebotomy and test ordering. Utilization data analysis was structured to satisfy specific concerns addressed in the ED staff survey. Results Observed tube utilization data showed that fluoride/oxalate, citrate, and serum separator tubes were frequently discarded unused, and that the actual utility of the rainbow draw for add-on testing and avoiding additional venipunctures was low. ED staff perceived that the rainbow draw was highly valuable, both to expedite add-on testing and to avoid additional venipunctures. Contrasting the objective (utilization data) and subjective (survey results) to drive changes in the standard ED blood collection reduced the estimated waste blood by 175 L/year. Conclusions Comparison of perceptions and objective utilization data drove process changes that were mutually agreeable to ED and laboratory staff. Although specifics of ED and laboratory work flows vary between institutions, the principles and strategy of this study are widely applicable.

Background Platelet polyphosphate is an inorganic procoagulant polymer of orthophosphate units that is stored in dense granules and is released upon platelet activation. Here, we describe an assay to measure polyphosphate on the surface of procoagulant human platelets. Methods and Results Recombinant Escherichia coli ‐expressed exopolyphosphatase deletion mutant PPX_Δ12 labeled with fluorescent Alexa488 dye was used as a polyphosphate probe in flow cytometry. PPX_Δ12‐Alexa488‐signal dose‐dependently increased with long‐chain polyphosphate binding to platelets. In contrast, short‐chain polyphosphate that is found in the supernatant of activated platelets, did not bind to the platelet surface. Both exopolyphosphatase treatment and polyphosphate pre‐incubation abolished PPX_Δ12‐Alexa488 binding to polyphosphate on platelets. Stimulation of platelets with thrombin receptor agonist Trap6, and P2Y 12 receptor activator ADP increased polyphosphate accumulation on platelet surfaces and PPX_Δ12‐Alexa488 signal in a dose‐dependent manner. Conclusion This study indicates that long‐chain polyphosphate binds to platelet plasma membranes and presents a promising diagnostic assay to measure this interaction on human platelets in platelet‐rich plasma. Future investigations will aim to determine if polyphosphate can be used as a novel biomarker of thrombosis. © 2016 International Clinical Cytometry Society