74 research outputs found
EMR Adoption: A User Perception Study
Despite promise of significant benefits, inadequate user acceptance has frequently limited the impact of EMR implementations. Using an action research approach, our team is participating in an EMR implementation at Aravind Eye Care System (AECS), one of the largest eye hospitals in the world, to observe its current practices, measure user perceptions of EMR, plan interventions, and assess their impact. Our proximate research objective is to develop interventions based on sound conceptual foundations and empirical validation rather than in an ad hoc manner, to facilitate EMR acceptance by AECS hospital staff. The ensuing goal is to learn from the post intervention findings to develop guidelines for EMR implementations, particularly in a developing country context. In this paper we report on the first phase of this study, and these initial results show how even simple analysis of perception patterns can help to customize and shape intervention plans
TissueGrinder, a novel technology for rapid generation of patient-derived single cell suspensions from solid tumors by mechanical tissue dissociation
IntroductionRecent advances hold promise of making personalized medicine a step closer to implementation in clinical settings. However, traditional sample preparation methods are not robust and reproducible. In this study, the TissueGrinder, a novel mechanical semi-automated benchtop device, which can isolate cells from tissue in a very fast and enzyme-free way is tested for cell isolation from surgically resected tumor tissues.MethodsThirty-three surgically resected tumor tissues from various but mainly pancreatic, liver or colorectal origins were processed by both novel TissueGrinder and explant method. An optimized processing program for tumors from pancreatic, liver or colorectal cancer was developed. The viability and morphological characteristics of the isolated cells were evaluated microscopically. Expression of pancreatic cancer markers was evaluated in cells isolated from pancreatic tumors. Finally, the effect of mechanical stress on the cells was evaluated by assessing apoptosis markers via western blotting.ResultsTissueGinder was more efficient in isolating cells from tumor tissue with a success rate of 75% when compared to explant method 45% in terms of cell outgrowth six weeks after processing. Cells isolated with TissueGinder had a higher abundance and were more heterogeneous in composition as compared to explant method. Mechanical processing of the cells with TissueGrinder does not lead to apoptosis but causes slight stress to the cells.DiscussionOur results show that TissueGrinder can process solid tumor tissues more rapidly and efficiently and with higher success rate compared to the conventionally used explant method. The results of the study suggest that the TissueGrinder might be a suitable method for obtaining cells, which is important for its application in individualized therapy. Due to the great variance in different tumor entities and the associated individual tissue characteristics, a further development of the dissociation protocol for other types of tumors and normal tissue will be targeted
Synaptotagminâ7 enhances calciumâsensing of chromaffin cell granules and slows discharge of granule cargos
Synaptotagminâ7 (Sytâ7) is one of two major calcium sensors for exocytosis in adrenal chromaffin cells, the other being synaptotagminâ1 (Sytâ1). Despite a broad appreciation for the importance of Sytâ7, questions remain as to its localization, function in mediating discharge of dense core granule cargos, and role in triggering release in response to physiological stimulation. These questions were addressed using two distinct experimental preparationsâmouse chromaffin cells lacking endogenous Sytâ7 (KO cells) and a reconstituted system employing cellâderived granules expressing either Sytâ7 or Sytâ1. First, using immunofluorescence imaging and subcellular fractionation, it is shown that Sytâ7 is widely distributed in organelles, including dense core granules. Total internal reflection fluorescence (TIRF) imaging demonstrates that the kinetics and probability of granule fusion in Sytâ7 KO cells stimulated by a native secretagogue, acetylcholine, are markedly lower than in WT cells. When fusion is observed, fluorescent cargo proteins are discharged more rapidly when only Sytâ1 is available to facilitate release. To determine the extent to which the aforementioned results are attributable purely to Sytâ7, granules expressing only Sytâ7 or Sytâ1 were triggered to fuse on planar supported bilayers bearing plasma membrane SNARE proteins. Here, as in cells, Sytâ7 confers substantially greater calcium sensitivity to granule fusion than Sytâ1 and slows the rate at which cargos are released. Overall, this study demonstrates that by virtue of its high affinity for calcium and effects on fusion pore expansion, Sytâ7 plays a central role in regulating secretory output from adrenal chromaffin cells.Sytâ7 is a highâaffinity calcium sensor expressed on chromaffin cell dense core granules. The purpose of this study was to assess the role of Sytâ7 in regulating the secretory response to cholinergic stimulation. Acetylcholine elicits secretion by elevating cytosolic calcium. The calcium sensitivity of exocytosis in cells lacking Sytâ7 is impaired. Cells that lack Sytâ7 also release peptide hormones at faster rates, implicating a role for Sytâ7 in regulating the exocytotic fusion pore. These data demonstrate that Sytâ7 has an important role in triggering exocytosis in cells and is likely to play a role in controlling hormone output, in situ.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162737/3/jnc14986.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162737/2/jnc14986-sup-0001-Supinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162737/1/jnc14986_am.pd
A Patient-centric, Attribute-based, Source-verifiable Framework for Health Record Sharing
The storage of health records in electronic format, and the
wide-spread sharing of these records among different health
care providers, have enormous potential benefits to the U.S.
healthcare system. These benefits include both improving
the quality of health care delivered to patients and reducing
the costs of delivering that care. However, maintaining the
security of electronic health record systems and the privacy
of the information they contain is paramount to ensure that
patients have confidence in the use of such systems. In this
paper, we propose a framework for electronic health record
sharing that is patient centric, i.e. it provides patients with
substantial control over how their information is shared and
with whom; provides for verifiability of original sources of
health information and the integrity of the data; and permits fine-grained decisions about when data can be shared
based on the use of attribute-based techniques for authorization and access control. We present the architecture of the
framework, describe a prototype system we have built based
on it, and demonstrate its use within a scenario involving
emergency responders' access to health record information
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Role of miR-483 in pancreatic alpha and beta cells
Diabetes mellitus is a disease associated with impaired glucose homeostasis leading to chronic hyperglycemia (elevated blood glucose level). Insulin and Glucagon, hormones secreted from pancreatic beta and alpha cells respectively play a vital role in balancing the normal blood glucose level. We have identified a microRNA (small non-coding regulatory RNA), miR-483 to be highly expressed in pancreatic beta cells when compared to alpha cells and more interestingly high glucose conditions further augmented its expression level. In this study, we have 1) demonstrated some important roles of miR-483 in regulating the functions of pancreatic beta and alpha cells by targeting SOCS3 (suppressor of cytokine signaling 3)-its working partner, 2) investigated the role of KrĂŒppel-like Factor 2 (KLF2) in regulating miR-483 expression in pancreatic beta cells, 3) revealed some other potential targets of miR-483 by HiSeq RNA sequencing after silencing miR-483 expression in pancreatic beta cells and 4) analyzed physiological functions of miR-483 in vivo under normal and high fat diet conditions using a pancreatic beta cell specific miR-483 knockout mouse model. Taken together, our results indicate that miR-483 has important roles in both regulating and protecting the functions of pancreatic alpha and beta cells. Thus, with more studies, we strongly believe that miR-483 can be used as a potential therapeutic agent for the treatment of diabetes mellitus
Pancreatic ÎČ-Cell O-GlcNAc Transferase Overexpression Increases Susceptibility to Metabolic Stressors in Female Mice
The nutrient-sensor O-GlcNAc transferase (Ogt), the sole enzyme that adds an O-GlcNAc-modification onto proteins, plays a critical role for pancreatic ÎČ-cell survival and insulin secretion. We hypothesized that ÎČ-cell Ogt overexpression would confer protection from ÎČ-cell failure in response to metabolic stressors, such as high-fat diet (HFD) and streptozocin (STZ). Here, we generated a ÎČ-cell-specific Ogt in overexpressing (ÎČOgtOE) mice, where a significant increase in Ogt protein level and O-GlcNAc-modification of proteins were observed in islets under a normal chow diet. We uncovered that ÎČOgtOE mice show normal peripheral insulin sensitivity and glucose tolerance with a regular chow diet. However, when challenged with an HFD, only female ÎČOgtOE (homozygous) Hz mice developed a mild glucose intolerance, despite increased insulin secretion and normal ÎČ-cell mass. While female mice are normally resistant to low-dose STZ treatments, the ÎČOgtOE Hz mice developed hyperglycemia and glucose intolerance post-STZ treatment. Transcriptome analysis between islets with loss or gain of Ogt by RNA sequencing shows common altered pathways involving pro-survival Erk and Akt and inflammatory regulators IL1ÎČ and NFkÎČ. Together, these data show a possible gene dosage effect of Ogt and the importance O-GlcNAc cycling in ÎČ-cell survival and function to regulate glucose homeostasis
Die Auswirkung von mechanischer Belastung auf Stammzellen zur Verbesserung der Knochenregeneration
Critical size bone defects and nonunion fractures remain difficult to treat. Although cellâloaded bone substitutes have improved bone ingrowth and formation, the lack of methods for achieving viability and the uniform distribution of cells in the scaffold limits their use as bone grafts. In addition, the predominant mechanical stimulus that drives early osteogenic cell maturation has not been clearly identified. Further, it is challenging to evaluate mechanical stimuli (i.e., deformation and fluidâflow-induced shear stress) because they are interdependent. This thesis compares different mechanical stimuli applied to cell-seeded scaffolds to develop bone grafts efficiently for the treatment of critical size bone defects. It also seeks to understand how deformation strain and interstitial fluidâflow-induced shear stress promote osteogenic lineage commitment. In this thesis, different scaffolds were seeded with primary human bone marrow mesenchymal stem cells (BM-MSCs) from different donors and subjected to static and dynamic culture conditions. In contrast with the static culture conditions, homogenous cell distributions were accomplished under dynamic culture conditions. Additionally, the induction of osteogenic lineage commitment without the addition of soluble factors was observed in the bioreactor system after one week of cell culture. To determine the role of mechanical stimuli, a bioreactor was developed to apply mechanical deformation force to a mesenchymal stem sell (MSC) line (telomerase reverse transcriptase (TERT)) expressing a strain-responsive AP-1 luciferase reporter construct on porous scaffolds. Increased luciferase expression was observed in the deformation strain compared with the shear stress strain. Furthermore, the expression of osteogenic lineage commitment markers such as osteonectin, osteocalcin (OC), osteopontin, runt-related transcription factor 2 (RUNX2), alkaline phosphate (AP), and collagen type 1 was significantly downregulated in the shear stress strain compared with the deformation strain. These findings establish that the deformation strain was the predominant stimulus causing skeletal precursors to undergo osteogenesis in earlier stages of osteogenic cell maturation. Finally, these findings were used to develop a bioreactor in vitro test system in which the effect of medication on osteoporosis could be tested. Primary human BM-MSCs from osteoporotic donors were subjected to strontium ranelate (an osteoporotic drug marketed as ProtelosÂź). Increased expression of collagen type 1 and calcification was seen in the drugtreated osteoporotic stem cells compared with the nondrug-treated osteoporotic stem cells. Thus, this bioreactor technology can easily be adapted into an in vitro osteoporotic drug testing system.Knochendefekte kritischer GröĂe und Frakturen mit Pseudoarthrose bleiben schwierig zu behandeln. Obwohl zellbeladene Knochenersatzprodukte das Einwachsen und die Bildung von Knochen verbessert haben, schrĂ€nken fehlende Methoden zur Erreichung der LebensfĂ€higkeit und der gleichmĂ€Ăigen Verteilung der Zellen im GerĂŒst die Verwendung von Knochenersatzprodukten als Knochentransplantate ein. Ebenfalls konnte der vorherrschende mechanische Reiz, der die frĂŒhe osteogene Zellreifung antreibt nicht eindeutig identifiziert werden. Ferner ist es schwierig, mechanische Reize (d. H. Verformung und durch FlĂŒssigkeitsströmung induzierte Scherbeanspruchung) zu bewerten, da diese GröĂen sie voneinander abhĂ€ngig sind. Diese Arbeit vergleicht die Auswirkung verschiedener mechanischer Reize auf mit Zellen besiedelte GerĂŒste, um herauszufinden, ob Knochentransplantate effizient entwickelt werden können damit sie fĂŒr die Behandlung von Knochendefekten einsetzbar sind. Des Weiteren wird versucht zu verstehen, wie Verformungsdehnung und durch interstitielle FlĂŒssigkeitsströmung induzierte Scherbeanspruchung die Bindung osteogener Linien fördern. In dieser Arbeit wurden verschiedene GerĂŒste mit primĂ€ren mesenchymalen Knochenmarkstammzellen (BM-MSCs) von verschiedenen Spendern ausgesĂ€t und statischen und dynamischen Kulturbedingungen ausgesetzt. Im Gegensatz zu den statischen Kulturbedingungen wurde unter dynamischen Kulturbedingungen eine homogene Zellverteilungen erreicht. ZusĂ€tzlich wurde im Bioreaktorsystem nach einer Woche Zellkultur eine Formung einer osteogenen Linienbindung auch ohne ZusĂ€tze von löslichen Faktoren beobachtet. Um die Rolle mechanischer Stimuli zu bestimmen, wurde ein Bioreaktor entwickelt, um auf porösen Scaffolds eine mechanische Verformungskraft auf eine mesenchymale Stammzelllinie (MSC) (Telomerase Reverse Transkriptase (TERT)) auszuĂŒben. Diese exprimiert ein auf Dehnung ansprechendes AP-1-Luciferase-Reporterkonstrukt. Eine erhöhte LuciferaseExpression wurde in der Verformungsdehnung im Vergleich zur Scherspannungsdehnung beobachtet. DarĂŒber hinaus war die Expression von osteogenen Linien Marker wie Osteonektin, Osteocalcin (OC), Osteopontin, Runt-verwandtem Transkriptionsfaktor 2 (RUNX2), alkalischem Phosphat (AP) und Kollagen Typ 1 in der Scherbeanspruchungsbelastung im Vergleich zur Verformungsdehnung signifikant herabreguliert. Diese Befunde belegen, dass die Verformungsdehnung der vorherrschende Stimulus war, der dazu fĂŒhrte, dass SkelettvorlĂ€ufer in frĂŒheren Stadien der osteogenen Zellreifung eine Osteogenese durchliefen. SchlieĂlich wurden diese Ergebnisse verwendet, um ein Bioreaktor-In-vitro-Testsystem zu entwickeln, in dem die Wirkung von Medikamenten auf Osteoporose getestet werden konnte. PrimĂ€re humane BM-MSCs von osteoporotischen Spendern wurden Strontiumranelat (einem als ProtelosÂź vertriebenen Arzneimittel zur Therapie der Osteoporose) ausgesetzt. Eine erhöhte Expression von Kollagen Typ 1 und Verkalkung wurde in den mit Arzneimitteln behandelten osteoporotischen Stammzellen im Vergleich zu den nicht mit Arzneimitteln behandelten osteoporotischen Stammzellen beobachtet. Somit kann diese Bioreaktortechnologie leicht in ein in vitro Arzneimitteltestsystem angepasst werden
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Remote electron and energy transfer sensitized photoisomerization of encapsulated stilbenes
Excited state chemistry and physics of molecules, in addition to their inherent electronic and steric features, depend on their immediate microenvironments. This study explores the influence of an organic capsule, slightly larger than the reactant molecule itself, on the excited state chemistry of the encapsulated molecule. Results presented here show that the confined molecule, in fact, is not isolated and can be manipulated from outside even without direct physical interaction. Examples where communication between a confined molecule and a free molecule present outside is brought about through electronic and energy transfer processes are presented. Geometric isomerization of octa acid encapsulated stilbenes induced by energy and electron transfer by cationic sensitizers that attach themselves to the anionic capsule is examined. The fact that isomerization occurs when the sensitizer present outside is excited illustrates that the reactant and sensitizer are communicating across the molecular wall of the capsule. Ability to remotely activate a confined molecule opens up new opportunities to bring about reactions of confined radical ions and triplet excited molecules generated via long distance energy and electron transfer processes
MicroRNA-30d induces insulin transcription factor MafA and insulin production by targeting mitogen-activated protein 4 kinase 4 (MAP4K4) in pancreatic ÎČ-cells
MicroRNAs (miRNAs) represent small noncoding RNAs that play a role in many diseases, including diabetes. miRNAs target genes important for pancreas development, ÎČ-cell proliferation, insulin secretion, and exocytosis. Previously, we documented that microRNA-30d (miR-30d), one of miRNAs up-regulated by glucose, induces insulin gene expression in pancreatic ÎČ-cells. Here, we found that the induction of insulin production by overexpression of miR-30d is associated with increased expression of MafA, a ÎČ-cell-specific transcription factor. Of interest, overexpression of miR-30d prevented the reduction in both MafA and insulin receptor substrate 2 (IRS2) with TNF-α exposure. Moreover, we identified that mitogen-activated protein 4 kinase 4 (MAP4K4), a TNF-α-activated kinase, is a direct target of miR-30d. Overexpression of miR-30d protected ÎČ-cells against TNF-α suppression on both insulin transcription and insulin secretion through the down-regulation of MAP4K4 by the miR-30d. A decrease of miR-30d expression was observed in the islets of diabetic db/db mice, in which MAP4K4 expression level was elevated. Our data support the notion that miR-30d plays multiple roles in activating insulin transcription and protecting ÎČ-cell functions from impaired by proinflammatory cytokines and underscore the concept that miR-30d may represent a novel pharmacological target for diabetes intervention. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc
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