151 research outputs found
Instrumenting a Fetal Membrane on a Chip as Emerging Technology for Preterm Birth Research
Preterm birth (PTB) is clinically defined as process of giving birth before 37 weeks of gestation and is a leading cause of death among neonates and children under the age of five. Prematurity remains a critical issue in developed countries, yet our understanding of the pathophysiology of PTB remains largely unknown. Among pregnancy complications, subclinical infections such as chorioamnionitis (CAM) are implicated in up to 70% of PTB cases. Specifically, CAM is characterized by the infection of the fetal membranes that surround the developing fetus and extend from the placenta, and is often associated with preterm, premature rupture of the fetal membranes (PPROM). The fetal membrane plays a key structural role in maintaining the fetal and maternal compartments of the gravid uterus. However, our understanding of the mechanisms of PPROM and the spatio-temporal progress of CAM remains vastly unknown. A lack of human-derived models have hindered our understanding of the mechanism that govern spontaneous PTB. Thus, in this short review, we discuss the emerging microfabrication technologies, specifically, organ-on-chip (OoCs) models, that seek to recapitulate the cellular and molecular context of the gestational membranes in vitro. These models show promise to facilitate the investigation of pathologic mechanisms that drive these disease conditions by mimicking the interactive contribution of the major cell types that make up the microenvironment of the fetal membrane and enable high throughput screening. Herein, we histologically characterize the microenvironment of the fetal membrane as a metric for scaling to recapitulate the functional components of the human fetal membrane. We review the current OoC models of the gravid uterus and conceptualize an “Instrumented Fetal Membrane on a Chip” (IFMOC) design as a prototype for PPROM and CAM research. Lastly, we discuss further applications of these OoC models for toxicological or pharmacological screening and personalized medicine. Fetal membrane OoCs offer an innovative and valuable platform to explore complex interactions between multiple drug types, toxic substances, and/or pathogenic microbes and their potential impacts on pregnancy outcomes. Further work will be required by integrating technological and analytical capabilities in order to characterize the fetal membrane microenvironment for preterm birth research
Business of Medicine: Developing Leaders in Academic Medicine and Learning Health Systems
Sylk Sotto-Santiago,1 Chemen Neal,2 Darren Caudill,1 Amanda Gist,1 Susannah Eastwick,3 Megan M Palmer,4 Mark W Geraci,5 David M Aronoff1 1Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; 2Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA; 3Kelley School of Business, Indiana University, Indianapolis, IN, USA; 4Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; 5Department of Medicine, University of Pittsburgh Health Sciences, Pittsburgh, PA, USACorrespondence: Sylk Sotto-Santiago, Department of Medicine at Indiana University School of Medicine, Emerson Hall 305 545 Barnhill Dr, Indianapolis, IN, 46202, USA, Email [email protected]: To develop healthcare professionals as clinical leaders in academic medicine and learning health system; and uncover organizational barriers, as well as pathways and practices to facilitate career growth and professional fulfillment.Methods: The Department of Medicine strategic plan efforts prompted the development of a business of medicine program informed by a needs assessment and realignment between academic departments and the healthcare system. The business of medicine leadership program launched in 2017. This descriptive case study presents its 5th year evaluation. Competencies were included from the Physician MBA program and from specific departmental needs and goals.Results: The program hosted a total of 102 clinical faculty. We had a 37% response rate of those retained at Indiana University School of Medicine. Overall, responses conveyed a positive experience in the course. Over 80% of participants felt that they gained skills in professional reflection, professional socialization, goal orientation, critical thinking, and commitment to profession. Financial literacy was overwhelmingly the skill that was reported to be the most valuable. Finance and accounting were mentioned as the most difficult concepts to understand. Familiar concepts included communication, LEAN, and wellness related topics. One hundred percent of participants said they are utilizing the skills gained in this program in their current role and that they would recommend the course to others.Conclusion: Business of medicine courses are more common now with programs describing elements informed by health system operations. However, few programs incorporate aspects of wellness, equity, diversity, inclusion, and health equity. Our program makes the case for multiple ways to develop inclusive leaders through a focused five-month program. It also recognizes that to really impact the learning health system, health professionals need leadership development and leaders suited to work alongside career administrators, all aiming towards a common goal of equitable patient-centered care.Keywords: business of medicine, professional development, business competencies, health equity, leadershi
Transient Increase in Cyclic AMP Localized to Macrophage Phagosomes
Cyclic AMP (cAMP) regulates many biological processes and cellular functions. The importance of spatially localized intracellular gradients of cAMP is increasingly appreciated. Previous work in macrophages has shown that cAMP is produced during phagocytosis and that elevated cAMP levels suppress host defense functions, including generation of proinflammatory mediators, phagocytosis and killing. However, the spatial and kinetic characteristics of cAMP generation in phagocytosing macrophages have yet to be examined. Using a Förster resonance energy transfer (FRET)-based cAMP biosensor, we measured the generation of cAMP in live macrophages. We detected no difference in bulk intracellular cAMP levels between resting cells and cells actively phagocytosing IgG-opsonized particles. However, analysis with the biosensor revealed a rapid decrease in FRET signal corresponding to a transient burst of cAMP production localized to the forming phagosome. cAMP levels returned to baseline after the particle was internalized. These studies indicate that localized increases in cAMP accompany phagosome formation and provide a framework for a more complete understanding of how cAMP regulates macrophage host defense functions
Post-operative Aspergillus mediastinitis in a man who was immunocompetent: a case report
<p>Abstract</p> <p>Introduction</p> <p><it>Aspergillus </it>spp. infections mainly affect patients who are immunocompromised, and are extremely rare in immunocompetent individuals.</p> <p>Case presentation</p> <p><it>Aspergillus </it>post-operative mediastinitis is considered to be a devastating infection, usually affecting patients undergoing cardiothoracic surgery with specific predisposing factors. We describe the case of an immunocompetent 68-year-old Caucasian man with severe chronic thromboembolic pulmonary hypertension, who underwent pulmonary thromboendarterectomy and developed post-operative mediastinitis due to <it>Aspergillus flavus</it>. The environmental control did not reveal the source of <it>A. flavus </it>infection and, despite combined antifungal therapy, our patient died as a result of septic shock and multiple organ failure.</p> <p>Conclusion</p> <p><it>Aspergillus </it>mediastinitis mainly affects patients after cardiosurgery operations with predisposing factors, and it is unusual in patients who are immunocompetent. The identification of the <it>Aspergillus </it>spp. source is often difficult, and there are no guidelines for the administration of pre-emptive therapy in this population of at-risk patients.</p
Impaired neonatal macrophage phagocytosis is not explained by overproduction of prostaglandin E2
<p>Abstract</p> <p>Background</p> <p>Neonates and young infants manifest increased susceptibility to bacterial, viral and fungal lung infections. Previous work has identified a role for eicosanoids in mediating host defense functions of macrophages. This study examines the relationship between alveolar macrophage (AM) host defense and production of lipid mediators during the neonatal period compared to adult AMs.</p> <p>Methods</p> <p>AMs were harvested from young (day 7 and day 14) and adult (~10 week) rats. The functionality of these cells was assessed by examining their ability to phagocytose opsonized targets, produce cytokines, eicosanoids and intracellular cAMP measured by enzyme immunoassays, and gene expression of proteins, enzymes and receptors essential for eicosanoid generation and phagocytosis measured by real time RT-PCR.</p> <p>Results</p> <p>AMs from young animals (day 7 and 14) were defective in their ability to phagocytose opsonized targets and produce tumor necrosis factor (TNF)- α. In addition, young AMs produce more prostaglandin (PG) E<sub>2</sub>, a suppressor of host defense, and less leukotriene (LT) B<sub>4</sub>, a promoter of host defense. Young AMs express higher levels of enzymes responsible for the production of PGE<sub>2 </sub>and LTB<sub>4</sub>; however, there was no change in the expression of E prostanoid (EP) receptors or LT receptors. Despite the similar EP profiles, young AMs are more responsive to PGE<sub>2 </sub>as evidenced by their increased production of the important second messenger, cyclic AMP. In addition, young AMs express higher levels of PDE3B and lower levels of PDE4C compared to adult AMs. However, even though the young AMs produced a skewed eicosanoid profile, neither the inhibition of PGE<sub>2 </sub>by aspirin nor the addition of exogenous LTB<sub>4 </sub>rescued the defective opsonized phagocytosis. Examination of a receptor responsible for mediating opsonized phagocytosis showed a significant decrease in the gene expression levels of the Fcgamma receptor in young (day 7) AMs compared to adult AMs.</p> <p>Conclusion</p> <p>These results suggest that elevated production of PGE<sub>2 </sub>and decreased production of LTB<sub>4 </sub>do not contribute to impaired opsonized macrophage phagocytosis and highlight an important difference between young and adult AMs.</p
Defective lung macrophage function in lung cancer +/- chronic obstructive pulmonary disease (COPD/emphysema)-mediated by cancer cell production of PGE2?
In chronic obstructive pulmonary disease (COPD/emphysema) we have shown a reduced ability of lung and alveolar (AM) macrophages to phagocytose apoptotic cells (defective ‘efferocytosis’), associated with evidence of secondary cellular necrosis and a resultant inflammatory response in the airway. It is unknown whether this defect is present in cancer (no COPD) and if so, whether this results from soluble mediators produced by cancer cells. We investigated efferocytosis in AM (26 controls, 15 healthy smokers, 37 COPD, 20 COPD+ non small cell lung cancer (NSCLC) and 8 patients with NSCLC without COPD) and tumor and tumor-free lung tissue macrophages (21 NSCLC with/13 without COPD). To investigate the effects of soluble mediators produced by lung cancer cells we then treated AM or U937 macrophages with cancer cell line supernatant and assessed their efferocytosis ability. We qualitatively identified Arachidonic Acid (AA) metabolites in cancer cells by LC-ESI-MSMS, and assessed the effects of COX inhibition (using indomethacin) on efferocytosis. Decreased efferocytosis was noted in all cancer/COPD groups in all compartments. Conditioned media from cancer cell cultures decreased the efferocytosis ability of both AM and U937 macrophages with the most pronounced effects occurring with supernatant from SCLC (an aggressive lung cancer type). AA metabolites identified in cancer cells included PGE2. The inhibitory effect of PGE2 on efferocytosis, and the involvement of the COX-2 pathway were shown. Efferocytosis is decreased in COPD/emphysema and lung cancer; the latter at least partially a result of inhibition by soluble mediators produced by cancer cells that include PGE2.Francis C. Dehle, Violet R. Mukaro, Craig Jurisevic, David Moffat, Jessica Ahern, Greg Hodge, Hubertus Jersmann, Paul N. Reynolds, Sandra Hodg
A-Kinase Anchoring in Dendritic Cells Is Required for Antigen Presentation
BACKGROUND: Dendritic cells (DC) are the most potent antigen presenting cells (APC) of the immune system. Prostaglandin E(2), cyclic AMP, and protein kinase A (PKA) have all been shown to regulate DC maturation and activity. In other cells, the ability of these molecules to convey their signals has been shown to be dependent on A-kinase anchoring proteins (AKAPs). Here we present evidence for the existence and functional importance of AKAPs in human DC. METHODOLOGY/PRINCIPAL FINDINGS: Using immunofluorescence and/or western analyses we identify AKAP79, AKAP149, AKAP95, AKAP LBC and Ezrin. We also demonstrate by western analysis that expression of AKAP79, AKAP149 and RII are upregulated with DC differentiation and maturation. We establish the functional importance of PKA anchoring in multiple aspects of DC biology using the anchoring inhibitor peptides Ht31 and AKAP-IS. Incubation of protein or peptide antigen loaded DC with Ht31 or AKAP-IS results in a 30-50% decrease in antigen presentation as measured by IFN-gamma production from antigen specific CD4(+) T cells. Incubation of LPS treated DC with Ht31 results in 80% inhibition of TNF-alpha and IL-10 production. Ht31 slightly decreases the expression of CD18 and CD11a and CD11b, slightly increases the basal expression of CD83, dramatically decreases the LPS stimulated expression of CD40, CD80 and CD83, and significantly increases the expression of the chemokine receptor CCR7. CONCLUSIONS: These experiments represent the first evidence for the functional importance of PKA anchoring in multiple aspects of DC biology
Cyclooxygenase-2 and prostaglandin E<inf>2</inf> signaling through prostaglandin receptor EP- 2 favor the development of myocarditis during acute trypanosoma cruzi infection
Inflammation plays an important role in the pathophysiology of Chagas disease, caused by Trypanosoma cruzi. Prostanoids are regulators of homeostasis and inflammation and are produced mainly by myeloid cells, being cyclooxygenases, COX-1 and COX-2, the key enzymes in their biosynthesis from arachidonic acid (AA). Here, we have investigated the expression of enzymes involved in AA metabolism during T. cruzi infection. Our results show an increase in the expression of several of these enzymes in acute T. cruzi infected heart. Interestingly, COX-2 was expressed by CD68+ myeloid heart-infiltrating cells. In addition, infiltrating myeloid CD11b+Ly6G- cells purified from infected heart tissue express COX-2 and produce prostaglandin E2 (PGE2) ex vivo. T. cruzi infections in COX-2 or PGE2- dependent prostaglandin receptor EP-2 deficient mice indicate that both, COX-2 and EP-2 signaling contribute significantly to the heart leukocyte infiltration and to the release of chemokines and inflammatory cytokines in the heart of T. cruzi infected mice. In conclusion, COX-2 plays a detrimental role in acute Chagas disease myocarditis and points to COX-2 as a potential target for immune intervention.This work was supported by (NG) grants from “Fondo de Investigaciones Sanitarias” (PS09/00538 and PI12/00289); “Universidad Autónoma de Madrid” and “Comunidad de Madrid” (CC08-UAM/SAL-4440/08); by (MF) grants from “Ministerio de Ciencia e Innovación” (SAF2010-17833); “Red de Investigación de Centros de Enfermedades Tropicales” (RICET RD12/0018/0004); European Union (HEALTH-FE-2008-22303, ChagasEpiNet); AECID Cooperation with Argentine (A/025417/09 and A/031735/10), Comunidad de Madrid (S-2010/BMD- 2332) and “Fundación Ramón Areces”. NAG was recipient of a ISCIII Ph.D. fellowship financed by the Spanish “Ministerio de Sanidad”. CCM and HC were recipients of contracts from SAF2010-17833 and PI060388, respectively.Peer Reviewe
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