22 results on '"Koprowski S"'
Search Results
2. Modelling and Simulation of Grinding Processes with Mounted Points: Part I of II - Grinding Tool Surface Characterization
- Author
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Uhlmann, E., Koprowski, S., Weingaertner, W.L., and Rolon, D.A.
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- 2016
- Full Text
- View/download PDF
3. Modelling and Simulation of Grinding Processes with Mounted Points: Part II of II - Fast Modelling Method for Workpiece Surface Prediction
- Author
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Uhlmann, E., Koprowski, S., Weingaertner, W.L., and Rolon, D.A.
- Published
- 2016
- Full Text
- View/download PDF
4. Tilt angle effects in surface grinding with mounted points
- Author
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Uhlmann, E., Borsoi Klein, T., and Koprowski, S.
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- 2014
- Full Text
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5. Factors that Predict Failure to Meet Merit-Based Incentive Payment System Quality Measures for Asymptomatic Carotid Endarterectomy
- Author
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Dua, A., primary, Koprowski, S., additional, Ali, F., additional, and Desai, S.S., additional
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- 2018
- Full Text
- View/download PDF
6. Modelling and simulation of grinding processes with mounted points. Part II of II
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Uhlmann, E., Koprowski, S., Weingaertner, W.L., Rolon, D.A., and Publica
- Abstract
Due to the importance of high surface quality of machined parts, considering its functional requirements, it is important to select a proper set of grinding parameters. Experimental trials are material, energy and time consuming. Therefore it is relevant for the industry to use a roughness model capable of simulating different grinding kinematics with different sets of parameters. This paper presents a fast and reliable method, for the NC-grinding process with abrasive mounted points, to reach this demand. In order to achieve this, numerical and empirical experiments were conducted proving the feasibility of the model for conventional, oscillating and tilt surface grinding.
- Published
- 2016
7. Cardiogenic Effects of Trichloroethylene and Trichloroacetic Acid Following Exposure during Heart Specification of Avian Development
- Author
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Drake, V. J., primary, Koprowski, S. L., additional, Hu, N., additional, Smith, S. M., additional, and Lough, J., additional
- Published
- 2006
- Full Text
- View/download PDF
8. Anticoagulation in Cirrhosis: Evidence for the Treatment of Portal Vein Thrombosis and Applications for Prophylactic Therapy.
- Author
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Martens K, McMurry HS, Koprowski S, Hum J, Haraga J, Jou JH, and Shatzel JJ
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- Anticoagulants adverse effects, Hemorrhage chemically induced, Humans, Liver Cirrhosis complications, Liver Cirrhosis drug therapy, Portal Vein, Thrombosis chemically induced, Thrombosis drug therapy, Venous Thrombosis drug therapy, Venous Thrombosis etiology, Venous Thrombosis prevention & control
- Abstract
The clinical utility of anticoagulation for patients with cirrhosis and asymptomatic portal vein thrombosis (PVT) is widely debated. Complex hemostatic derangements in cirrhosis that increase risk of both bleeding and thrombosis, as well as a lack of randomized controlled data, limit conclusive assessments regarding optimal management of anticoagulation in this setting. In this review, we summarize the relevant literature pertaining to PVT in cirrhosis, including the effect of untreated PVT on the natural progression of liver disease and the overall impact of anticoagulation on clot burden and other relevant clinical outcomes. Apart from patients who are symptomatic or listed for liver transplantation, data supporting anticoagulation for the treatment of PVT is limited and without clear consensus guidelines. In patients with cirrhosis without PVT, emerging evidence for the role of prophylactic anticoagulation to mitigate the progression of fibrosis suggests an optimal risk-benefit tradeoff with decreased rates of liver decompensation and mortality, without a heightened risk of bleeding. In summation, as our understanding of the role of both prophylactic and therapeutic anticoagulation in cirrhosis continues to evolve, ongoing risk stratification of patients with asymptomatic PVT demands further attention., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
9. Chronic liver disease, thrombocytopenia and procedural bleeding risk; are novel thrombopoietin mimetics the solution?
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Olson SR, Koprowski S, Hum J, McCarty OJT, DeLoughery TG, and Shatzel JJ
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- Chronic Disease, Hemorrhage pathology, Humans, Liver Diseases blood, Liver Diseases pathology, Hemorrhage etiology, Liver Diseases complications, Thrombocytopenia blood, Thrombopoietin therapeutic use
- Abstract
Chronic liver disease (CLD) alters normal hemostatic and thrombotic systems via multiple mechanisms including reduced platelet function and number, leading to challenging peri-operative planning. Hepatic thrombopoietin (TPO) synthesis is reduced in CLD, leading to several recent randomized, placebo-controlled trials examining the utility of TPO-mimetics to increase platelet counts prior to surgery. While these trials do suggest that TPO-mimetics are efficacious at increasing platelet counts in patients with CLD and have led to several recent drug approvals in this space by the U.S. Food & Drug Administration, it remains unclear whether these results translate to the relevant clinical endpoint of reduced perioperative bleeding rate and severity. In this article, we review several recently-published, phase 3 trials on the TPO-mimetics eltrombopag, avatrombopag and lusutrombopag, and discuss the clinical significance of their results.
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- 2019
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10. Spur-Cell Anemia.
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Keyserling K and Koprowski S
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- Adult, Anemia, Hemolytic etiology, Fatal Outcome, Hepatic Encephalopathy complications, Humans, Male, Acanthocytes pathology, Anemia, Hemolytic blood, Hepatic Encephalopathy blood
- Published
- 2018
- Full Text
- View/download PDF
11. Factors that Predict Failure to Meet Merit-Based Incentive Payment System Quality Measures for Asymptomatic Carotid Endarterectomy.
- Author
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Dua A, Koprowski S, Ali F, and Desai SS
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- Aged, Aged, 80 and over, Asymptomatic Diseases, Carotid Artery Diseases diagnosis, Carotid Artery Diseases mortality, Centers for Medicare and Medicaid Services, U.S. economics, Databases, Factual, Endarterectomy, Carotid adverse effects, Endarterectomy, Carotid mortality, Endarterectomy, Carotid standards, Female, Florida, Hospital Costs standards, Humans, Length of Stay economics, Logistic Models, Male, Middle Aged, Odds Ratio, Physician Incentive Plans standards, Process Assessment, Health Care standards, Quality Improvement economics, Quality Indicators, Health Care standards, Reimbursement, Incentive standards, Risk Factors, Stroke etiology, Time Factors, Treatment Outcome, United States, Carotid Artery Diseases economics, Carotid Artery Diseases surgery, Endarterectomy, Carotid economics, Physician Incentive Plans economics, Process Assessment, Health Care economics, Quality Indicators, Health Care economics, Reimbursement, Incentive economics
- Abstract
Background: The Physician Quality Reporting System (PQRS) created by the Centers for Medicare and Medicaid Services financially penalizes providers who fail to meet expected quality of care measures. The purpose of this study is to evaluate the factors that predict failure to meet PQRS measures for carotid endarterectomy (CEA)., Methods: PQRS measure 260 (discharge by postoperative day 2 following CEA in asymptomatic patients) and 346 (rate of postoperative stroke or death following CEA in asymptomatic patients) were evaluated using hospital records from the state of Florida from 2008 to 2012. The impact of demographics, comorbidities, hospital factors, admission variables, and individual practitioner data upon timely discharge, and postoperative stroke and death. Odds ratios, 95% confidence intervals, and significance (P < 0.05) were determined through the development of a logistic regression model. Surgeons were identified by national provider identifier number, and practitioner data obtained from the American Medical Association Physician Masterfile., Results: A total of 34,235 patient records and 701 providers were identified over the 5-year period. Significant negative predictors for PQRS measure 260 included weekend admission (odds ratio [OR], 2.9), Medicaid (OR, 2.4), surgeon historical postoperative stroke rate >2.0% (OR, 1.7), African-American race (OR, 2.0), and female gender (OR, 1.3). The presence of any of these factors was associated with a 13.5% rate of failure. The most significant negative predictor for PQRS measure 346 was surgeon postoperative stroke rate >2.0% (OR, 6.2 for stroke and OR, 29.0 for death). Surgeons in this underperforming group had worse outcomes compared to their peers despite having patients with fewer risk factors for poor outcomes. Surgeon specialty, board certification, and case volume do not impact either PQRS measures., Conclusions: Selected groups of patients and surgeons with a disproportionately high rate of postoperative stroke are at risk of failing to meet PQRS pay for performance quality measures. Awareness of these risk factors may help mitigate and minimize the risk of adversely impacting the value stream. Further evaluation of the causative factors that lead to surgeon underperformance could help to improve the quality of care., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
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12. Treatment of Stress Velopharyngeal Incompetence With Injection of Hyaluronic Acid.
- Author
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Koprowski S, VanLue MJ, and McCormick ME
- Subjects
- Adolescent, Female, Humans, Stress, Physiological, Treatment Outcome, Velopharyngeal Insufficiency physiopathology, Endoscopy methods, Fluoroscopy methods, Hyaluronic Acid administration & dosage, Velopharyngeal Insufficiency diagnostic imaging, Velopharyngeal Insufficiency drug therapy, Viscosupplements administration & dosage
- Abstract
Stress velopharyngeal incompetence (VPI) is a challenging clinical entity that can be managed by a variety of surgical and nonsurgical approaches. We describe the case of a clarinetist who presented with nasal air escape while playing. She had successful improvement in her symptoms after targeted injection of a hyaluronic acid compound to her posterior pharyngeal wall. Our objective is to describe the safety and efficacy of this technique, to emphasize the multidisciplinary management of patients with stress VPI, and to review the importance of both nasopharyngoscopy and videofluoroscopy in their evaluation.
- Published
- 2018
- Full Text
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13. Progressive shortfall in open aneurysm experience for vascular surgery trainees with the impact of fenestrated and branched endovascular technology.
- Author
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Dua A, Koprowski S, Upchurch G, Lee CJ, and Desai SS
- Subjects
- Aortic Aneurysm, Abdominal diagnostic imaging, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation adverse effects, Blood Vessel Prosthesis Implantation instrumentation, Blood Vessel Prosthesis Implantation trends, Clinical Competence, Curriculum, Databases, Factual, Diffusion of Innovation, Education, Medical, Graduate trends, Endovascular Procedures adverse effects, Endovascular Procedures instrumentation, Endovascular Procedures trends, Hospitals, Teaching, Humans, Learning Curve, Logistic Models, Prosthesis Design, Retrospective Studies, Stents, Surgeons trends, Time Factors, United States, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis Implantation education, Education, Medical, Graduate methods, Endovascular Procedures education, Internship and Residency trends, Surgeons education
- Abstract
Background: In 2014, we published a series of articles in the Journal of Vascular Surgery that detailed the decrease in volume of open aneurysm repair (OAR) completed for abdominal aortic aneurysm (AAA) by vascular surgery trainees. At that time, only data points from 2000 through 2011 were available, and reliable predictions could only be made through 2015. Lack of data on endovascular aneurysm repair (EVAR) using fenestrated (FEVAR) and branched (BrEVAR) endografts also affected our findings. Despite these limitations, our predictions for OAR completed by vascular trainees were accurate for 2012 to 2014. This report uses updated data points through 2014 in conjunction with data on FEVAR and BrEVAR obtained from industry to predict trends in OAR and how it will affect vascular surgery training through 2020., Methods: An S-curve modified logistic function was used to model the effect of introducing new technologies (EVAR, FEVAR, BrEVAR) on the standard management of AAA with OAR starting in the year 2000, similar to the technique that we have previously described. Weighted samples and data from the United States Census Bureau were used in conjunction with volume estimates derived from the National Inpatient Sample, State Inpatient Databases, and industry sources to determine trends in OAR and EVAR. The number of cases completed at teaching hospitals was calculated using the National Inpatient Sample, and Accreditation Council for Graduate Medical Education case logs were used to forecast the number of cases completed by vascular surgery trainees through 2020. Sensitivity analysis and trend analysis were completed., Results: Approximately 45,000 AAA repairs are completed annually in the United States, but only 15% of these are now completed using OAR compared with >50% just a decade ago. Further, with the accelerating adoption of FEVAR and BrEVAR, and expanding indications for standard EVAR, our model predicts that <3000 OARs will be completed annually by 2020. Because only a subset of these cases are completed at teaching institutions, our model predicts that a vascular surgery trainee in a fellowship program will complete only one to two OARs, whereas trainees in a 0+5 program may complete two to three OARs., Conclusions: Our initial prediction in the 2014 report was that vascular trainees would complete approximately five OARs by 2020. After incorporating new data on BrEVAR, FEVAR, and the accelerating pace of EVAR use between 2012 and 2014, it now appears that vascular trainees will complete one to three OARs during their training., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
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14. Potential Molecular Targeted Therapeutics: Role of PI3-K/Akt/mTOR Inhibition in Cancer.
- Author
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Sokolowski KM, Koprowski S, Kunnimalaiyaan S, Balamurugan M, Gamblin TC, and Kunnimalaiyaan M
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- Antineoplastic Agents chemistry, Carcinoma, Hepatocellular enzymology, Humans, Liver Neoplasms enzymology, Phosphatidylinositol 3-Kinases metabolism, Protein Kinase Inhibitors chemistry, Proto-Oncogene Proteins c-akt metabolism, TOR Serine-Threonine Kinases metabolism, Antineoplastic Agents pharmacology, Carcinoma, Hepatocellular drug therapy, Liver Neoplasms drug therapy, Molecular Targeted Therapy, Phosphoinositide-3 Kinase Inhibitors, Protein Kinase Inhibitors pharmacology, Proto-Oncogene Proteins c-akt antagonists & inhibitors, TOR Serine-Threonine Kinases antagonists & inhibitors
- Abstract
Primary liver cancer is one of the most commonly occurring cancers worldwide. Hepatocellular carcinoma (HCC) represents the majority of primary liver cancer and is the 3rd most common cause of cancer-related deaths globally. Survival rates of patients with HCC are dependent upon early detection as concomitant liver dysfunction and advanced disease limits traditional therapeutic options such as resection or ablation. Unfortunately, at the time of diagnosis, most patients are not eligible for curative surgery and have a five-year relative survival rate less than 20%, leading to systemic therapy as the only option. Currently, sorafenib is the only approved systemic therapy; however, it has a limited survival advantage and low efficacy prompting alternative strategies. The inception of sorafenib for HCC systemic therapy and the understanding involved of cancer therapy have led to an enhanced focus of the PI3-k/Akt/mTOR pathway as a potential area of targeting including pan and isoform-specific PI3-K inhibitors, Akt blockade, and mTOR suppression. The multitude, expanding roles, and varying clinical trials of these inhibitors have led to an increase in knowledge and availability for current and future studies. In this review, we provide a review of the literature with the aim to focus on potential targets for HCC therapies as well as an in depth focus on Akt inhibition.
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- 2016
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15. Curcumin-mediated regulation of Notch1/hairy and enhancer of split-1/survivin: molecular targeting in cholangiocarcinoma.
- Author
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Koprowski S, Sokolowski K, Kunnimalaiyaan S, Gamblin TC, and Kunnimalaiyaan M
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- Antineoplastic Agents pharmacology, Apoptosis drug effects, Basic Helix-Loop-Helix Transcription Factors metabolism, Bile Duct Neoplasms metabolism, Cell Cycle drug effects, Cell Line, Tumor, Cell Survival drug effects, Cholangiocarcinoma metabolism, Curcumin pharmacology, Drug Screening Assays, Antitumor, Homeodomain Proteins metabolism, Humans, Inhibitor of Apoptosis Proteins metabolism, Receptor, Notch1 metabolism, Survivin, Transcription Factor HES-1, Antineoplastic Agents therapeutic use, Bile Duct Neoplasms drug therapy, Cholangiocarcinoma drug therapy, Curcuma, Curcumin therapeutic use, Phytotherapy
- Abstract
Background: Cholangiocarcinoma (CCA) is highly malignant and characterized by poor prognosis with chemotherapeutic resistance. Therefore, continued development of novel, effective approaches are needed. Notch expression is markedly upregulated in CCA, but the utility of Notch1 inhibition is not defined. Based on recent findings, we hypothesized that curcumin, a polyphenolic phytochemical, suppresses CCA growth in vitro via inhibition of Notch1 signaling., Methods: Established CCA cell lines CCLP-1 and SG-231 were treated with varying concentrations of curcumin (0-20 μM). Viability was assessed through 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and clonogenic assays. Evaluation of apoptosis was determined via Western analysis for apoptotic markers and Caspase-Glo 3/7 assay. Cell lysates were further analyzed via Western blotting for Notch1/HES-1/survivin pathway expression, cell cycle progression, and survival., Results: Curcumin-treated CCA cells exhibited reduced viability compared with control treatment. Statistically significant reductions in cell viability were observed with curcumin treatment at concentrations of 7.5, 10, and 15 μM by approximately 10%, 48%, and 56% for CCLP-1 and 13%, 25%, and 50% for SG-231, respectively. On Western analysis, concentrations of ≥10 μM showed reductions in Notch1, HES-1, and survivin. Apoptosis was evidenced by an increase in expression of cleaved poly [ADP] ribose polymerase and an increase in caspase activity. Cyclin D1 (cell cycle progression) expression levels were also reduced with treatment., Conclusions: Curcumin effectively induces CCA (CCLP-1 and SG-231) growth suppression and apoptosis at relatively low treatment concentrations when compared with the previous research. A concomitant reduction of Notch1, HES-1, and survivin expression in CCA cell lines provides novel evidence for a potential antitumorigenic mechanism-of-action. To our knowledge, this is the first report showing reduction in HES-1 expression via protein analysis after treatment with curcumin. Such findings merit further investigation of curcumin-mediated inhibition of Notch signaling in CCA either alone or in combination with chemotherapeutic agents., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
16. Thrombopoietin receptor agonists protect human cardiac myocytes from injury by activation of cell survival pathways.
- Author
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Baker JE, Su J, Koprowski S, Dhanasekaran A, Aufderheide TP, and Gross GJ
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- Cell Hypoxia drug effects, Cell Hypoxia physiology, Cell Survival drug effects, Cell Survival physiology, Cells, Cultured, Dose-Response Relationship, Drug, Humans, Myocytes, Cardiac drug effects, Proto-Oncogene Mas, Signal Transduction drug effects, Thrombopoietin pharmacology, Benzoates pharmacology, Cardiotonic Agents pharmacology, Hydrazines pharmacology, Myocytes, Cardiac physiology, Pyrazoles pharmacology, Receptors, Thrombopoietin agonists, Receptors, Thrombopoietin physiology, Signal Transduction physiology
- Abstract
Thrombopoietin confers immediate protection against injury caused by ischemia/reperfusion in the rat heart. Eltrombopag is a small molecule agonist of the thrombopoietin receptor, the physiologic target of thrombopoietin. However, the ability of eltrombopag and thrombopoietin to protect human cardiac myocytes against injury and the mechanisms underlying myocyte protection are not known. Human cardiac myocytes (n = 6-10/group) were treated with eltrombopag (0.1-30.0 µM) or thrombopoietin (0.1-30.0 ng/ml) and then subjected to 5 hours of hypoxia (95% N2/5% CO2) and 16 hours of reoxygenation to determine their ability to confer resistance to myocardial injury. The thrombopoietin receptor c-Mpl was detected in unstimulated human cardiac myocytes by Western blotting. Eltrombopag and thrombopoietin confer immediate protection to human cardiac myocytes against injury from hypoxia/reoxygenation by decreasing necrotic and apoptotic cell death in a concentration-dependent manner, with an optimal concentration of 3 µM for eltrombopag and 1.0 ng/ml for thrombopoietin. The extent of protection conferred with eltrombopag is equivalent to that of thrombopoietin. Eltrombopag and thrombopoietin activate multiple prosurvival pathways; inhibition of Janus kinase-2, proto-oncogene tyrosine-protein kinase, protein kinase B/phosphatidylinositol-3 kinase, p44/42 mitogen-activated protein kinase (MAPK), and p38 MAPK abolished cardiac myocyte protection by eltrombopag and thrombopoietin. Eltrombopag and thrombopoietin may represent important and potent agents for immediately and substantially increasing protection of human cardiac myocytes, and may offer a long-lasting benefit through activation of prosurvival pathways during ischemia., (Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.)
- Published
- 2015
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17. Cardiac injury after 10 gy total body irradiation: indirect role of effects on abdominal organs.
- Author
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Lenarczyk M, Lam V, Jensen E, Fish BL, Su J, Koprowski S, Komorowski RA, Harmann L, Migrino RQ, Li XA, Hopewell JW, Moulder JE, and Baker JE
- Subjects
- Animals, Base Sequence, DNA Primers, Intestines radiation effects, Kidney radiation effects, Male, Rats, Risk Factors, Heart radiation effects, Radiation Dosage, Radiation Injuries, Experimental etiology, Whole-Body Irradiation
- Abstract
The objective of this study was to determine whether radiation-induced injury to the heart after 10 Gy total body irradiation (TBI) is direct or indirect. Young male WAG/RijCmcr rats received a 10 Gy single dose using TBI, upper hemi-body (UHB) irradiation, lower hemi-body (LHB) irradiation, TBI with the kidneys shielded or LHB irradiation with the intestines shielded. Age-matched, sham-irradiated rats served as controls. The lipid profile, kidney injury, heart and liver morphology and cardiac function were determined up to 120 days after irradiation. LHB, but not UHB irradiation, increased the risk factors for cardiac disease as well as the occurrence of cardiac and kidney injury in a way that was quantitatively and qualitatively similar to that observed after TBI. Shielding of the kidneys prevented the increases in risk factors for cardiac disease. Shielding of the intestines did not prevent the increases in risk factors for cardiac disease. There was no histological evidence of liver injury 120 days after irradiation. Injury to the heart from irradiation appears to be indirect, supporting the notion that injury to abdominal organs, principally the kidneys, is responsible for the increased risk factors for and the occurrence of cardiac disease after TBI and LHB irradiation.
- Published
- 2013
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18. Intestinal microbiota determine severity of myocardial infarction in rats.
- Author
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Lam V, Su J, Koprowski S, Hsu A, Tweddell JS, Rafiee P, Gross GJ, Salzman NH, and Baker JE
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Cytokines blood, Drinking Water, Humans, Intestines drug effects, Leptin blood, Leptin pharmacology, Myocardial Reperfusion Injury physiopathology, Probiotics therapeutic use, Rats, Rats, Inbred Dahl, Vancomycin pharmacology, Intestines microbiology, Metagenome drug effects, Myocardial Infarction pathology, Myocardial Infarction physiopathology, Myocardial Reperfusion Injury pathology, Myocardial Reperfusion Injury prevention & control
- Abstract
Signals from the intestinal microbiota are important for normal host physiology; alteration of the microbiota (dysbiosis) is associated with multiple disease states. We determined the effect of antibiotic-induced intestinal dysbiosis on circulating cytokine levels and severity of ischemia/reperfusion injury in the heart. Treatment of Dahl S rats with a minimally absorbed antibiotic vancomycin, in the drinking water, decreased circulating leptin levels by 38%, resulted in smaller myocardial infarcts (27% reduction), and improved recovery of postischemic mechanical function (35%) as compared with untreated controls. Vancomycin altered the abundance of intestinal bacteria and fungi, measured by 16S and 18S ribosomal DNA quantity. Pretreatment with leptin (0.12 μg/kg i.v.) 24 h before ischemia/reperfusion abolished cardioprotection produced by vancomycin treatment. Dahl S rats fed the commercially available probiotic product Goodbelly, which contains the leptin-suppressing bacteria Lactobacillus plantarum 299v, also resulted in decreased circulating leptin levels by 41%, smaller myocardial infarcts (29% reduction), and greater recovery of postischemic mechanical function (23%). Pretreatment with leptin (0.12 μg/kg i.v.) abolished cardioprotection produced by Goodbelly. This proof-of-concept study is the first to identify a mechanistic link between changes in intestinal microbiota and myocardial infarction and demonstrates that a probiotic supplement can reduce myocardial infarct size.
- Published
- 2012
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19. Making stem cells infarct avid.
- Author
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Zhao M, Barron MR, Li Z, Koprowski S, Hall CL, and Lough J
- Subjects
- Animals, Cell Survival, Cells, Cultured, Mice, Myocytes, Cardiac cytology, Myocytes, Cardiac metabolism, Protein Binding, Rats, Surface Properties, Synaptotagmin I chemistry, Synaptotagmin I metabolism, Embryonic Stem Cells transplantation, Myocardial Infarction therapy
- Abstract
A major factor limiting the engraftment of transplanted stem cells after myocardial infarction is the low rate of retention in the infarcted site. Our long-term objective is to improve engraftment by enabling stem cells to recognize and bind infarcted tissue. To this end, we proposed to modify the surface of embryonic stem cells (ESCs) with the C2A domain of synaptotagmin I; this allows the engineered stem cells to bind to dead and dying cardiac cells by recognizing phosphatidylserine (PS). The latter is a molecular marker for apoptotic and necrotic cells. The C2A domain of synaptotagmin I, which binds PS with high affinity and specificity, was attached to the surface of mouse ESCs using the biotin-avidin coupling mechanism. Binding of C2A-ESCs to dead and dying cardiomyocytes was tested in vitro. After the surface modification, cellular physiology was examined for viability, pluripotency, and differentiation potential. C2A covalently attached to the ESC surface at an average of about 1 million C2A molecules per cell under mild conjugation reaction conditions. C2A-ESCs avidly bound to dying, but not viable, cardiomyocytes in culture. The normal physiology of C2A-modified ESCs was maintained. The binding of C2A-ESCs to moribund cardiomyocytes demonstrates that the retention of transplanted cells may be improved by conferring these cells with the ability to bind infarcted tissue. Once established, this novel approach may be applicable to other types of transplanted therapeutic cells.
- Published
- 2010
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20. Homozygous disruption of the Tip60 gene causes early embryonic lethality.
- Author
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Hu Y, Fisher JB, Koprowski S, McAllister D, Kim MS, and Lough J
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- Animals, Apoptosis physiology, Blastocyst cytology, Blastocyst enzymology, Embryo, Mammalian enzymology, Exons genetics, Gastrula enzymology, Genotype, Heterozygote, Histone Acetyltransferases genetics, Homozygote, Lysine Acetyltransferase 5, Mice, Morula metabolism, Trans-Activators, Apoptosis genetics, Cell Proliferation, Embryo Loss genetics, Histone Acetyltransferases metabolism
- Abstract
Tat-interactive protein 60 (Tip60) is a member of the MYST family, proteins of which are related by an atypical histone acetyltransferase (HAT) domain. Although Tip60 has been implicated in cellular activities including DNA repair, apoptosis, and transcriptional regulation, its function during embryonic development is unknown. We ablated the Tip60 gene (Htatip) from the mouse by replacing exons 1-9 with a neomycin resistance cassette. Development and reproduction of wild-type and heterozygous animals were normal. However, homozygous ablation of the Tip60 gene caused embryolethality near the blastocyst stage of development, as evidenced by inability of cells in Tip60-null blastocysts to hatch and survive in culture. Monitoring cell proliferation and death by detecting EdU-substituted DNA and TUNEL labeling revealed suppression of cell proliferation concomitant with increased cell death as Tip60-null cells attempted to hatch from blastocysts. These findings indicate that Tip60 is essential for cellular survival during the blastocyst-gastrula transition of embryogenesis., (Copyright 2009 Wiley-Liss, Inc.)
- Published
- 2009
- Full Text
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21. The epiphany of data warehousing technologies in the pharmaceutical industry.
- Author
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Barrett JS and Koprowski SP Jr
- Subjects
- Drug Industry economics, Drug Industry trends, Electronic Data Processing trends, Terminology as Topic, Drug Industry organization & administration, Electronic Data Processing organization & administration, Pharmacology, Clinical methods, Technology, Pharmaceutical trends
- Abstract
The highly competitive pharmaceutical industry has seen many external changes to its landscape as companies consume each other increasing their pipelines while removing redundant functions and processes. Internally, companies have sought to streamline the discovery and development phases in an attempt to improve candidate selection and reduce the time to regulatory filing. In conjunction with efforts to screen and develop more compounds faster and more efficiently, database management systems (DBMS) have been developed for numerous groups supporting various R&D efforts. An outgrowth of DBMS evolution has been the birth of data warehousing. Often confused with DBMS, data warehousing provides a conduit for data residing across platforms, networks, and in different data structures. Through the use of metadata, the warehouse establishes connectivity of varied data stores (operational detail data, ODD) and permits identification of data ownership, location and transaction history. This evolution has closely mirrored and in some ways been driven by the electronic submission (formerly CANDA). The integration of the electronic submissions and document management with R&D data warehousing initiatives should provide a platform by which companies can address compliance with 21 CFR Part 11. Now more than ever "corporate memory" is being extended to the data itself. The when, why and how of successes and failures are constantly being probed by R&D management teams. The volume of information being generated by today's pharmaceutical companies requires mining of historical data on a routine basis. Data warehousing represents a core technology to assist in this endeavor. New initiatives in this field address the necessity of data portals through which warehouse data can be web-enabled and exploited by diverse data customers both internal and external to the company. The epiphany of data warehousing technologies within the pharmaceutical industry has begun and promises to change the way in which companies process and provide data to regulatory agencies. The improvements in drug discovery and reduction in development timelines remain to be seen but would seem to be rational if such technology is fully exploited.
- Published
- 2002
22. Data warehouse implementation with clinical pharmacokinetic/pharmacodynamic data.
- Author
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Koprowski SP Jr and Barrett JS
- Subjects
- Adult, Databases, Factual, Female, Humans, Male, Terminology as Topic, Biometry methods, Electronic Data Processing, Information Management methods, Information Management organization & administration, Pharmacokinetics, Pharmacology
- Abstract
Objectives: We have created a data warehouse for human pharmacokinetic (PK) and pharmacodynamic (PD) data generated primarily within the Clinical PK Group of the Drug Metabolism and Pharmacokinetics (DM&PK) Department of DuPont Pharmaceuticals., Methods: Data which enters an Oracle-based LIMS directly from chromatography systems or through files from contract research organizations are accessed via SAS/PH.Kinetics, GLP-compliant data analysis software residing on individual users' workstations. Upon completion of the final PK or PD analysis, data are pushed to a predefined location. Data analyzed/created with other software (i.e., WinNonlin, NONMEM, Adapt, etc.) are added to this file repository as well. The warehouse creates views to these data and accumulates metadata on all data sources defined in the warehouse. The warehouse is managed via the SAS/Warehouse Administrator product that defines the environment, creates summarized data structures, and schedules data refresh., Results: The clinical PK/PD warehouse encompasses laboratory, biometric, PK and PD data streams. Detailed logical tables for each compound are created/updated as the clinical PK/PD data warehouse is populated. The data model defined to the warehouse is based on a star schema. Summarized data structures such as multidimensional data bases (MDDB), infomarts, and datamarts are created from detail tables. Data mining and querying of highly summarized data as well as drill-down to detail data is possible via the creation of exploitation tools which front-end the warehouse data. Based on periodic refreshing of the warehouse data, these applications are able to access the most current data available and do not require a manual interface to update/populate the data store. Prototype applications have been web-enabled to facilitate their usage to varied data customers across platform and location. The warehouse also contains automated mechanisms for the construction of study data listings and SAS transport files for eventual incorporation into an electronic submission., Conclusions: This environment permits the management of online analytical processing via a single administrator once the data model and warehouse configuration have been designed. The expansion of the current environment will eventually connect data from all phases of research and development ensuring the return on investment and hopefully efficiencies in data processing unforeseen with earlier legacy systems.
- Published
- 2002
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