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Patwardhan R, Nanda S, Wagner J, Stockter T, Dehmelt L, Nalbant P. Cdc42 activity in the trailing edge is required for persistent directional migration of keratinocytes. Mol Biol Cell 2024; 35:br1. [PMID: 37910204 PMCID: PMC10881163 DOI: 10.1091/mbc.e23-08-0318] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/13/2023] [Indexed: 11/03/2023] Open
Abstract
Fibroblasts migrate discontinuously by generating transient leading-edge protrusions and irregular, abrupt retractions of a narrow trailing edge. In contrast, keratinocytes migrate persistently and directionally via a single, stable, broad protrusion paired with a stable trailing-edge. The Rho GTPases Rac1, Cdc42 and RhoA are key regulators of cell protrusions and retractions. However, how these molecules mediate cell-type specific migration modes is still poorly understood. In fibroblasts, all three Rho proteins are active at the leading edge, suggesting short-range coordination of protrusive Rac1 and Cdc42 signals with RhoA retraction signals. Here, we show that Cdc42 was surprisingly active in the trailing-edge of migrating keratinocytes. Elevated Cdc42 activity colocalized with the effectors MRCK and N-WASP suggesting that Cdc42 controls both myosin activation and actin polymerization in the back. Indeed, Cdc42 was required to maintain the highly dynamic contractile acto-myosin retrograde flow at the trailing edge of keratinocytes, and its depletion induced ectopic protrusions in the back, leading to decreased migration directionality. These findings suggest that Cdc42 is required to stabilize the dynamic cytoskeletal polarization in keratinocytes, to enable persistent, directional migration.
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Affiliation(s)
- Rutuja Patwardhan
- Department of Molecular Cell Biology, Center of Medical Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany
| | - Suchet Nanda
- TU Dortmund University, Fakultät für Chemie und Chemische Biologie, 44227 Dortmund, Germany
| | - Jessica Wagner
- Department of Molecular Cell Biology, Center of Medical Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany
| | - Tom Stockter
- Department of Molecular Cell Biology, Center of Medical Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany
| | - Leif Dehmelt
- TU Dortmund University, Fakultät für Chemie und Chemische Biologie, 44227 Dortmund, Germany
| | - Perihan Nalbant
- Department of Molecular Cell Biology, Center of Medical Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany
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2
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Hensel A, Stahl P, Moews L, König L, Patwardhan R, Höing A, Schulze N, Nalbant P, Stauber RH, Knauer SK. The Taspase1/Myosin1f-axis regulates filopodia dynamics. iScience 2022; 25:104355. [PMID: 35601920 PMCID: PMC9121324 DOI: 10.1016/j.isci.2022.104355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 03/04/2022] [Accepted: 04/28/2022] [Indexed: 11/15/2022] Open
Abstract
The unique threonine protease Tasp1 impacts not only ordered development and cell proliferation but also pathologies. However, its substrates and the underlying molecular mechanisms remain poorly understood. We demonstrate that the unconventional Myo1f is a Tasp1 substrate and unravel the physiological relevance of this proteolysis. We classify Myo1f as a nucleo-cytoplasmic shuttle protein, allowing its unhindered processing by nuclear Tasp1 and an association with chromatin. Moreover, we show that Myo1f induces filopodia resulting in increased cellular adhesion and migration. Importantly, filopodia formation was antagonized by Tasp1-mediated proteolysis, supported by an inverse correlation between Myo1f concentration and Tasp1 expression level. The Tasp1/Myo1f-axis might be relevant in human hematopoiesis as reduced Tasp1 expression coincided with increased Myo1f concentrations and filopodia in macrophages compared to monocytes and vice versa. In sum, we discovered Tasp1-mediated proteolysis of Myo1f as a mechanism to fine-tune filopodia formation, inter alia relevant for cells of the immune system. Myosin1f is a nucleo-cytoplasmic shuttle protein temporarily located in the nucleus Myosin1f induces filopodia resulting in increased cellular adhesion and migration The protease Taspase1 cleaves Myosin1f, thereby impairing its function Taspase1 and Myosin1f inversely correlate in immune cell differentiation
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Affiliation(s)
- Astrid Hensel
- Department of Molecular Biology II, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
- Corresponding author
| | - Paul Stahl
- Department of Molecular Biology II, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
| | - Lisa Moews
- Department of Molecular Biology II, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
| | - Lena König
- Department of Molecular Biology II, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
| | - Rutuja Patwardhan
- Department of Molecular Cell Biology, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
| | - Alexander Höing
- Department of Molecular Biology II, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
| | - Nina Schulze
- Imaging Center Campus Essen (ICCE), Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
| | - Perihan Nalbant
- Department of Molecular Cell Biology, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
| | - Roland H. Stauber
- Department of Molecular and Cellular Oncology/ENT, University Mainz Medical Center, 55131 Mainz, Germany
| | - Shirley K. Knauer
- Department of Molecular Biology II, Center of Medical Biotechnology (ZMB), University Duisburg-Essen, 45141 Essen, Germany
- Corresponding author
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3
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Graessl M, Koch J, Calderon A, Kamps D, Banerjee S, Mazel T, Schulze N, Jungkurth JK, Patwardhan R, Solouk D, Hampe N, Hoffmann B, Dehmelt L, Nalbant P. An excitable Rho GTPase signaling network generates dynamic subcellular contraction patterns. J Cell Biol 2017; 216:4271-4285. [PMID: 29055010 PMCID: PMC5716289 DOI: 10.1083/jcb.201706052] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 08/25/2017] [Accepted: 09/08/2017] [Indexed: 12/22/2022] Open
Abstract
Rho GTPase-based signaling networks control cellular dynamics by coordinating protrusions and retractions in space and time. Here, we reveal a signaling network that generates pulses and propagating waves of cell contractions. These dynamic patterns emerge via self-organization from an activator-inhibitor network, in which the small GTPase Rho amplifies its activity by recruiting its activator, the guanine nucleotide exchange factor GEF-H1. Rho also inhibits itself by local recruitment of actomyosin and the associated RhoGAP Myo9b. This network structure enables spontaneous, self-limiting patterns of subcellular contractility that can explore mechanical cues in the extracellular environment. Indeed, actomyosin pulse frequency in cells is altered by matrix elasticity, showing that coupling of contractility pulses to environmental deformations modulates network dynamics. Thus, our study reveals a mechanism that integrates intracellular biochemical and extracellular mechanical signals into subcellular activity patterns to control cellular contractility dynamics.
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Affiliation(s)
- Melanie Graessl
- Department of Molecular Cell Biology, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Johannes Koch
- Department of Molecular Cell Biology, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Abram Calderon
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology and Fakultät für Chemie und Chemische Biologie, TU Dortmund University, Dortmund, Germany
| | - Dominic Kamps
- Department of Molecular Cell Biology, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology and Fakultät für Chemie und Chemische Biologie, TU Dortmund University, Dortmund, Germany
| | - Soumya Banerjee
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology and Fakultät für Chemie und Chemische Biologie, TU Dortmund University, Dortmund, Germany
| | - Tomáš Mazel
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology and Fakultät für Chemie und Chemische Biologie, TU Dortmund University, Dortmund, Germany
| | - Nina Schulze
- Department of Molecular Cell Biology, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Jana Kathrin Jungkurth
- Department of Molecular Cell Biology, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology and Fakultät für Chemie und Chemische Biologie, TU Dortmund University, Dortmund, Germany
| | - Rutuja Patwardhan
- Department of Molecular Cell Biology, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Djamschid Solouk
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology and Fakultät für Chemie und Chemische Biologie, TU Dortmund University, Dortmund, Germany
| | - Nico Hampe
- Institute of Complex Systems, Forschungszentrum Jülich, Jülich, Germany
| | - Bernd Hoffmann
- Institute of Complex Systems, Forschungszentrum Jülich, Jülich, Germany
| | - Leif Dehmelt
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology and Fakultät für Chemie und Chemische Biologie, TU Dortmund University, Dortmund, Germany
| | - Perihan Nalbant
- Department of Molecular Cell Biology, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
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4
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Kellum A, Jagiello-Gruszfeld A, Bondarenko IN, Patwardhan R, Messam C, Mostafa Kamel Y. A randomized, double-blind, placebo-controlled, dose ranging study to assess the efficacy and safety of eltrombopag in patients receiving carboplatin/paclitaxel for advanced solid tumors. Curr Med Res Opin 2010; 26:2339-46. [PMID: 20735290 DOI: 10.1185/03007995.2010.510051] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES Eltrombopag, an oral, nonpeptide thrombopoietin receptor agonist, has been shown to increase platelet counts in adults with chronic immune thrombocytopenia and chronic hepatitis C. This multicenter phase 2 study assessed the efficacy and safety of eltrombopag in patients receiving first-line carboplatin/paclitaxel for the treatment of advanced solid tumors. RESEARCH DESIGN AND METHODS Patients (N = 183) were randomized to placebo or eltrombopag 50 mg, 75 mg, or 100 mg given orally following chemotherapy on days 2 through 11 of each 21-day cycle, for at least two cycles. The primary endpoint was the difference in platelet count from day 1 in cycle 2 to the platelet nadir in cycle 2. CLINICAL TRIAL REGISTRY NUMBER NCT00102726. RESULTS Although the primary endpoint was not met, postnadir platelet counts increased during cycles 1 and 2 in all eltrombopag treatment groups compared with placebo. The most commonly reported adverse events across all study arms (including placebo) were nausea and alopecia and eltrombopag was generally well tolerated. CONCLUSIONS This study provides preliminary information that eltrombopag does increase platelets in patients receiving chemotherapy for advanced solid tumors. Further investigation is needed to identify the optimal dose(s) and schedule of eltrombopag in patients receiving myelosuppressive chemotherapy.
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Affiliation(s)
- A Kellum
- North Mississippi Hematology & Oncology Associates LTD, Tupelo, MO, USA
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5
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Jahagirdar S, Patwardhan R, Dhakephalkar PK. Curing plasmid-mediated vancomycin resistance in Staphylococcus aureus using herbal naphthoquinones. J Hosp Infect 2008; 70:289-91. [PMID: 18799244 DOI: 10.1016/j.jhin.2006.04.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Accepted: 04/07/2006] [Indexed: 11/24/2022]
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6
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Imtiaz SA, Shah SL, Patwardhan R, Palizban HA, Ruppenstein J. Detection, Diagnosis and Root Cause Analysis of Sheet-Break in a Pulp and Paper Mill with Economic Impact Analysis. CAN J CHEM ENG 2008. [DOI: 10.1002/cjce.5450850413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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7
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Koka K, Patwardhan R, Besio W. Computer simulation and tank experimental verification of concentric ring electrodes. Conf Proc IEEE Eng Med Biol Soc 2007; 2004:2243-6. [PMID: 17272173 DOI: 10.1109/iembs.2004.1403653] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Brain activity generates electrical potentials that are spatio-temporal in nature. EEG is the least costly and most widely used non-invasive technique for diagnosing many problems related to the brain. It has very good temporal resolution, but does not poses high spatial resolution primarily due to the blurring affects of the volume conductor. The surface Laplacian enhances the spatial resolution and selectivity of the surface electrical activity as it takes the second spatial derivative of the potential. In an attempt to increase the localization and spatial selectivity a five point finite difference method has recently been used in a bipolar electrode configuration. Here we report on a nine point finite difference method as a model for the tripolar electrode configuration. We have designed a computer simulation to model electrode properties and a dipole at various depths below the electrode surface. A tank experimental was setup to verify the computer simulated potentials. In the simulation and tank experiment, a concentric ring electrode of 2 cm diameter was used. We found that the tripolar electrode configuration has significantly better localization and signal to noise ratio than the bipolar and quasi-bipolar configurations.
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Affiliation(s)
- K Koka
- Department of Biomedical Engineering, Louisiana Technical University--Ruston, LA, USA
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8
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Tubbs RS, Patwardhan R, Palmer CA, Kelly DR, Elton S, Blount JP, Bebin M, Grabb PA. Histological appearance of a chronically stimulated vagus nerve in a pediatric patient. Pediatr Neurosurg 2001; 35:99-102. [PMID: 11549921 DOI: 10.1159/000050398] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Histological analysis of chronically stimulated human vagus nerves is lacking in the literature. In this study, we describe the first microscopic findings in a chronically stimulated left vagus nerve from a pediatric patient. Our results show many histological changes in and around the stimulated nerve with severe demyelination. Further long-term clinical and postmortem examinations of chronically stimulated vagus nerves in both children and adults are needed to ascertain whether prolonged exposure to electrical current can cause clinical dysfunction of this nerve.
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Affiliation(s)
- R S Tubbs
- Division of Pediatric Neurosurgery, Children's Hospital of Alabama, University of Alabama at Birmingham, 1600 7th Avenue South, Birmingham, AL 35233, USA
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9
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Phillips LS, Grunberger G, Miller E, Patwardhan R, Rappaport EB, Salzman A. Once- and twice-daily dosing with rosiglitazone improves glycemic control in patients with type 2 diabetes. Diabetes Care 2001; 24:308-15. [PMID: 11213884 DOI: 10.2337/diacare.24.2.308] [Citation(s) in RCA: 239] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To determine the efficacy of rosiglitazone compared with placebo in reducing hyperglycemia. RESEARCH DESIGN AND METHODS After a 4-week placebo run-in period, 959 patients were randomized to placebo or rosiglitazone (total daily dose 4 or 8 mg) for 26 weeks. The primary measure of efficacy was change in the HbA1c concentration. RESULTS Rosiglitazone produced dosage-dependent reductions in HbA1c of 0.8, 0.9, 1.1, and 1.5% in the 4 mg o.d., 2 mg b.i.d., 8 mg o.d., and 4 mg b.i.d. groups, respectively, compared with placebo. Clinically significant decreases from baseline in HbA1c were observed in drug-naive patients at all rosiglitazone doses and in patients previously treated with oral monotherapy at rosiglitazone 8 mg o.d. and 4 mg b.i.d. Clinically significant decreases from baseline in HbA1c were also observed with rosiglitazone 4 mg b.i.d. in patients previously treated with combination oral therapy. Approximately 33% of drug-naive patients treated with rosiglitazone achieved HbA1c < or =7% at study end. The proportions of patients with at least one adverse event were comparable among the rosiglitazone and placebo groups. There was no evidence of hepatotoxicity in any treatment group. There were statistically significant increases in weight and serum lipids in all rosiglitazone treatment groups compared with placebo. For LDL and HDL cholesterol, the observed increase appeared to be dose related. CONCLUSIONS Rosiglitazone at total daily doses of 4 and 8 mg significantly improved glycemic control in patients with type 2 diabetes and was well tolerated.
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Affiliation(s)
- L S Phillips
- Division of Endocrinology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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10
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Abstract
This study evaluated the efficacy and safety of rosiglitazone monotherapy in patients with type 2 diabetes. After a 4-week placebo run-in period, 493 patients with type 2 diabetes were randomized to receive rosiglitazone [2 or 4 mg twice daily (bd)] or placebo for 26 weeks. The primary end point was change in hemoglobin A(1c); other variables assessed included fasting plasma glucose, fructosamine, endogenous insulin secretion, urinary albumin excretion, serum lipids, and adverse events. Rosiglitazone (2 and 4 mg bd) decreased mean hemoglobin A(1c) relative to placebo by 1.2 and 1.5 percentage points, respectively, and reduced fasting plasma glucose concentrations relative to placebo by 3.22 and 4.22 mmol/L, respectively. Fasting plasma insulin and insulin precursor molecules decreased significantly. Homeostasis model assessment estimates indicate that rosiglitazone (2 and 4 mg bd) reduced insulin resistance by 16.0% and 24.6%, respectively, and improved ss-cell function over baseline by 49.5% and 60.0%, respectively. Urinary albumin excretion decreased significantly in the rosiglitazone (4 mg bd) group. There was no increase in adverse events with rosiglitazone. In the short-term, rosiglitazone is an insulin sensitizer that is effective and safe as monotherapy in patients with type 2 diabetes who are inadequately controlled by lifestyle interventions.
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Affiliation(s)
- H E Lebovitz
- Department of Medicine, State University of New York, Brooklyn, New York 11203, USA.
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11
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Fonseca V, Rosenstock J, Patwardhan R, Salzman A. Effect of metformin and rosiglitazone combination therapy in patients with type 2 diabetes mellitus: a randomized controlled trial. JAMA 2000; 283:1695-702. [PMID: 10755495 DOI: 10.1001/jama.283.13.1695] [Citation(s) in RCA: 415] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Most antidiabetic agents target only 1 of several underlying causes of diabetes. The complementary actions of the antidiabetic agents metformin hydrochloride and rosiglitazone maleate may maintain optimal glycemic control in patients with type 2 diabetes; therefore, their combined use may be indicated for patients whose diabetes is poorly controlled by metformin alone. OBJECTIVE To evaluate the efficacy of metformin-rosiglitazone therapy in patients whose type 2 diabetes is inadequately controlled with metformin alone. DESIGN Randomized, double-blind, placebo-controlled trial from April 1997 and March 1998. SETTING Thirty-six outpatient centers in the United States. PATIENTS Three hundred forty-eight patients aged 40 to 80 years with a mean fasting plasma glucose level of 12.0 mmol/L (216 mg/dL), a mean glycosylated hemoglobin level of 8.8%, and a mean body mass index of 30.1 kg/m2 were randomized. INTERVENTIONS Patients were assigned to receive 2.5 g/d of metformin plus placebo (n = 116); 2.5 g/d of metformin plus 4 mg/d of rosiglitazone (n = 119); or 2.5 g/d of metformin and 8 mg/d of rosiglitazone (n = 113) for 26 weeks. MAIN OUTCOME MEASURES Glycosylated hemoglobin levels, fasting plasma glucose levels, insulin sensitivity, and beta-cell function, compared between baseline and week 26, by treatment group. RESULTS Glycosylated hemoglobin levels, fasting plasma glucose levels, insulin sensitivity, and beta-cell function improved significantly with metformin-rosiglitazone therapy in a dose-dependent manner. The mean levels of glycosylated hemoglobin decreased by 1.0% in the 4 mg/d metformin-rosiglitazone group and by 1.2% in the 8 mg/d metformin-rosiglitazone group and fasting plasma glucose levels by 2.2 mmol/L (39.8 mg/dL) and 2.9 mmol/L (52.9 mg/dL) compared with the metformin-placebo group (P<.001 for all). Of patients receiving 8 mg/d of metformin-rosiglitazone, 28.1% achieved a glycosylated hemoglobin level of 7% or less [corrected]. Dose-dependent increases in body weight and total and low-density lipoprotein cholesterol levels were observed (P<.001 for both rosiglitazone groups vs placebo). The proportion of patients reporting adverse experiences was comparable across all groups. CONCLUSIONS Our data suggest that combination treatment with once-daily metformin-rosiglitazone improves glycemic control, insulin sensitivity, and beta-cell function more effectively than treatment with metformin alone.
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Affiliation(s)
- V Fonseca
- Department of Medicine, Tulane University, New Orleans, LA 70112, USA.
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12
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Abstract
AIMS To evaluate the clinical efficacy and safety of rosiglitazone as a once daily treatment for Type 2 diabetes mellitus (DM). METHODS Three hundred and sixty-nine patients with Type 2 DM (mean age 63 years; mean body mass index (BMI) 29.4 kg/m2) were enrolled in a double-blind, parallel group, placebo-controlled, dose-ranging study. Patients were randomly assigned to receive placebo or rosiglitazone at doses of 4, 8, or 12 mg daily for 8 weeks. RESULTS At 8 weeks, fasting plasma glucose (FPG) decreased significantly in the rosiglitazone 4 mg, 8 mg, and 12 mg groups (-0.9, -2.0 and -1.7 mmol/l; P = 0.0003, < 0.0001, and < 0.0001, respectively) compared with placebo (+0.4 mmol/l). The improvements in FPG were dose ordered for 4 and 8 mg/ day. The 12 mg/day dose produced no additional improvement. There were small decreases in haemoglobin and haematocrit in the rosiglitazone treatment groups. The overall incidence of adverse experiences was similar in all treatment groups, including placebo with no evidence of hypoglycaemia or hepatotoxicity. CONCLUSIONS Rosiglitazone improves glycaemic control when given once daily to treat Type 2 diabetes mellitus and is well tolerated at doses up to and including 12 mg.
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Affiliation(s)
- J J Nolan
- Department of Endocrinology, St. James's Hospital, Dublin, Ireland
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13
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Raskin P, Rappaport EB, Cole ST, Yan Y, Patwardhan R, Freed MI. Rosiglitazone short-term monotherapy lowers fasting and post-prandial glucose in patients with type II diabetes. Diabetologia 2000; 43:278-84. [PMID: 10768088 DOI: 10.1007/s001250050045] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIMS/HYPOTHESIS The short-term efficacy, safety and tolerability of rosiglitazone were compared with placebo in patients with Type II (non-insulin-dependent) diabetes mellitus in a dose-ranging study. METHODS After a 2-week placebo run-in phase, 303 patients were randomly assigned to 8 weeks of treatment with twice-daily placebo or 2, 4 or 6 mg of rosiglitazone. RESULTS All rosiglitazone doses significantly reduced fasting plasma glucose compared with baseline. All rosiglitazone treatment groups showed significantly reduced peak postprandial glucose concentrations compared with baseline (p < 0.001) and with placebo (p < 0.0001) and reduced postprandial glucose excursion, without an increase in the area under the postprandial insulin concentration-time curve. Rosiglitazone at 4 and 6 mg twice daily prevented the increase in HbA1c observed in the placebo group. C peptide and serum insulin concentrations were significantly reduced from baseline in all rosiglitazone treatment groups. In all rosiglitazone treatment groups, nonesterified fatty acids decreased significantly (p < 0.0001) and triglycerides did not change. Although total LDL and HDL cholesterol increased significantly in the rosiglitazone treatment groups, total cholesterol/HDL ratios did not change significantly. The proportion of patients with one or more adverse event was similar in all four treatment groups. No patient showed evidence of hepatotoxicity. CONCLUSION/INTERPRETATION Rosiglitazone given twice daily significantly reduced fasting and postprandial glucose concentrations, C peptide, insulin and nonesterified fatty acids in Type II diabetic patients. The glucose-lowering effect of the 4-mg twice-daily dose of rosiglitazone was similar to that of 6-mg twice daily, suggesting that 4 mg twice daily should be the maximum clinical dose.
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Affiliation(s)
- P Raskin
- University of Texas Southwestern Medical Center, Dallas, USA
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14
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Abstract
Hepatotoxic reactions in patients receiving carbamazepine (CBZ) therapy have been reported, and some have been considered fatal. We present two patients with hepatic dysfunction secondary to CBZ therapy. Liver biopsies were compatible with hepatotoxic damage, and the symptoms were reversible with medication withdrawal. Our patients are representative of those in the literature, most of whom have granulomatous hepatitis and sometimes have associated cholangitis. The patients with fatal reactions differed clinically and pathologically from the others, and may represent a different entity. The clinical syndrome resembles a viral hepatitis. Elderly patients seem to be particularly susceptible and their hepatic function should be monitored closely when CBZ therapy is initiated.
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Affiliation(s)
- S Horowitz
- Department of Neurology, St. Vincents Hospital, University of Massachusetts Medical School, Worcester 01604
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15
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Küpfer A, Patwardhan R, Ward S, Schenker S, Preisig R, Branch RA. Stereoselective metabolism and pharmacogenetic control of 5-phenyl-5-ethylhydantoin (nirvanol) in humans. J Pharmacol Exp Ther 1984; 230:28-33. [PMID: 6747829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Aromatic hydroxylation of 5-phenyl-5-ethylhydantoin (PEH) has been investigated in humans. Single oral doses of S-PEH (247 mumol) were given to seven extensive and seven poor hydroxylators of mephenytoin. Urinary recovery of PEH and 5-(4-hydroxyphenyl)-5-ethylhydantoin (4-OH-PEH) indicated that all extensive metabolizer subjects excreted appreciable quantities of 4-OH-PEH, whereas all poor metabolizer subjects had only trace amounts of 4-OH-PEH in their urine. Four extensive metabolizer subjects received dual radiolabeled (S-[14C]PEH, R-[3H]PEH) pseudoracemic (494 mumol R-PEH, 494 mumol S-PEH) PEH and had serial urine and blood samples collected over 16 days. The urinary excretion rates of S-PEH and S-4-OH-PEH had half-lives of approximately 4.5 days whereas those of R-PEH and R-4-OH-PEH were approximately 10 days. The initial S/R ratio of 4-OH-PEH in urine was 14:1 whereas that of PEH was 1:1. Stereoselective hydroxylation in these four subjects was confirmed by the negligible recovery of 4-OH-PEH after oral administration of R-PEH (494 mumol). After racemic administration, the sum of S-and R-PEH plasma concentrations declined biexponentially with half-lives of the alpha- and beta-phases being consistent with the total plasma concentration reflecting the sum of the different rates of elimination of the two enantiomers. These results are consistent with the hypothesis that the same drug metabolizing enzymes are involved in the aromatic hydroxylation of S-mephenytoin and S-PEH.
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Abstract
Deficient aromatic hydroxylation of S-mephenytoin was observed in an index subject during a kinetic study of stereoselective metabolism of mephenytoin. A genetic basis for this defect was suggested by decreased urinary recovery of 3-methyl-5-(4-hydroxyphenyl)-5-ethylhydantoin (4-OH-M) in the 24 hr after oral racemic mephenytoin in two brothers of the propositus. The parents and a third brother had urinary recoveries of 4-OH-M of the same order as in a group of 20 normal subjects. The kinetic implications of this defect were studied in the index subject and compared with four normal subjects after a single oral dose of differentially radiolabeled pseudoracemic mephenytoin (5 microCi of 14C-S-mephenytoin, 45 microCi of H3-R-mephenytoin, and 11.5 mumol/kg of both S- and R-mephenytoin) followed by single oral doses of 1.4 mmol of unlabeled racemic mephenytoin daily the next 4 days. In normal subjects, there was substrate stereoselective metabolism with the S-enantiomer rapidly excreted as 4-OH-M and the R-enantiomer slowly excreted as 5-phenyl-5-ethylhydantoin (PEH). Stereoselective metabolism persisted during repeated dosing. In the hydroxylation-deficient subject, there was no evidence of stereoselective metabolism, recovery of 4-OH-M was low, and both enantiomers were slowly excreted, predominantly as PEH. Plasma PEH concentrations and urinary PEH excretion rates were approximately twice that in normal subjects. Thus a genetic deficiency in ability to hydroxylate S-mephenytoin results in the S-enantiomer metabolization by the alternate route of demethylation to PEH that cumulates, thereby, in comparison to the normal, effectively doubling the dose of total hydantoin.
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17
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Ghishan FK, Patwardhan R, Greene HL. Fetal alcohol syndrome: inhibition of placental zinc transport as a potential mechanism for fetal growth retardation in the rat. J Lab Clin Med 1982; 100:45-52. [PMID: 7086268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Growth retardation is one of the principal features of fetal alcohol syndrome. The cause of this growth retardation is unknown. Because of the clinical similarities between fetal alcohol syndrome and prenatal zinc deficiency, we studied in vivo the effect of short-term and long-term ethanol ingestion during pregnancy on placental transport of zinc in pair-fed rats. Our results indicate that both short- and long-term ethanol depressed zinc-65 uptake in the placenta and fetus by 40% and 30%, respectively, compared to pair-fed controls (p less than 0.05). Total zinc concentration in fetuses of the long-term ethanol group was significantly decreased compared to pair-fed controls (p less than 0.05). Although the mechanism of action of ethanol in producing the fetal alcohol syndrome maybe multiple, our findings suggest that a decrease in the availability of zinc to the fetus may represent one of the contributory factors in the growth retardation of fetal alcohol syndrome.
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18
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Solammadevi SV, Patwardhan R. Herpes esophagitis. Am J Gastroenterol 1982; 77:48-50. [PMID: 7064964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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19
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Abstract
Recently cimetidine (Tagamet), a widely used drug for peptic ulcer disease, was found to decrease serum levels of calcium and immunoreactive parathyroid hormone in patients with hyperparathyroidism. Since parathyroid hormone action is closely related to calcium homeostasis, we studied the effect of cimetidine on intestinal calcium transport. An in vivo perfusion technique was used for the study of net transport and lumen to mucosa flux of 45calcium. Our results indicate a significant decrease in net calcium transport and lumen to mucosa flux of 45calcium in the rats injected with cimetidine, compared to control rats. Direct addition of cimetidine to the perfusion solution did not alter transport rates significantly. The mechanism by which cimetidine affects calcium transport may be secondary to its effect on the release of parathyroid hormone from the parathyroid gland or an effect on vitamin D metabolism.
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20
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Hoyumpa AM, Patwardhan R, Antonson D, Nichols S, Gray JP. Effect of thiamin deficiency and acute ethanol ingestion on jejunal glucose transport in rats. Am J Clin Nutr 1981; 34:14-9. [PMID: 7192487 DOI: 10.1093/ajcn/34.1.14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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21
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Abstract
The disposition of chlordiazepoxide (Librium) and diazepam (Valium), compounds which are initially degraded by oxidative processes, differs from that of oxazepam (Serax) and lorazepam (Ativan, drugs which are inactivated by conjugation with glucuronic acid. Liver disease and cimetidine impair the elimination of the former agents, but not the latter two benzodiazepines. In addition, ethanol inhibits the metabolism of chlordiazepoxide and diazepam. The present studies were performed to determine the effect of short-term ethanol administration on glucuronidation and elimination of lorazepam in dogs and humans. Because, in dogs, lorazepam has a high extraction ratio (approximately 0.9) with an anticipated large presystemic elimination, the influence of ethanol on the presystemic (first-pass) elimination of lorazepam was determined. Administration of p.o. lorazepam to five healthy dogs 1 hr after i.v. saline or ethanol (3 gm/kg) reduced the presystemic elimination of lorazepam by 52% (p less than 0.05). In man, lorazepam has a low (approximately by 0.05) extraction ratio and only a small first-pass effect. Short-term administration of ethanol (0.8 gm/kg followed by 0.5 gm/kg p.o. every 5 hr for four doses) reduced i.v. lorazepam clearance by 18% (p less than 0.03). In dogs and man, ethanol did not significantly alter lorazepam t1/2, plasma protein binding, or distribution volume (Vd beta). The results suggest that short-term ethanol administration impairs the conjugation of lorazepam in dogs and man.
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22
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Desmond PV, Patwardhan R, Parker R, Schenker S, Speeg KV. Effect of cimetidine and other antihistaminics on the elimination of aminopyrine, phenacetin and caffeine. Life Sci 1980; 26:1261-8. [PMID: 6104763 DOI: 10.1016/0024-3205(80)90071-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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23
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Patwardhan R, Doss LL. Radiation injuries to the bowel. An overview. Mo Med 1978; 75:616-9. [PMID: 723842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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24
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Patwardhan R. Primary malignant melanomas of the vagina. Curr Surg 1978; 35:68-70. [PMID: 639539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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25
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Prusty S, Bhargava S, Talwar JR, Chopra P, Rao IM, Venugopal P, Patwardhan R, Gopinath N. Mediastinal tumors and cysts. Int Surg 1973; 58:775-9. [PMID: 4750829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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