1
|
Kandalkar SR, Ramaiah PA, Joshi M, Wavhal A, Waman Y, Raje AA, Tambe A, Ansari S, De S, Palle VP, Mookhtiar KA, Deshpande AM, Barawkar DA. Modifications of flexible nonyl chain and nucleobase head group of (+)-erythro-9-(2's-hydroxy-3's-nonyl)adenine [(+)-EHNA] as adenosine deaminase inhibitors. Bioorg Med Chem 2017; 25:5799-5819. [PMID: 28951094 DOI: 10.1016/j.bmc.2017.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 10/18/2022]
Abstract
A series of terminal nonyl chain and nucleobase modified analogues of (+)-EHNA (III) were synthesized and evaluated for their ability to inhibit adenosine deaminase (ADA). The constrained carbon analogues of (+)-EHNA, 7a-7h, 10a-c, 12, 13, 14 and 17a-c appeared very potent with Ki values in the low nanomolar range. Thio-analogues of (+)-EHNA 24a-e wherein 5'C of nonyl chain replaced by sulfur atom found to be less potent compared to (+)-EHNA. Docking of the representative compounds into the active site of ADA was performed to understand structure-activity relationships. Compounds 7a (Ki: 1.1nM) 7b (Ki: 5.2nM) and 26a (Ki: 5.9nM) showed suitable balance of potency, microsomal stability and demonstrated better pharmacokinetic properties as compared to (+)-EHNA and therefore may have therapeutic potential for various inflammatory diseases, hypertension and cancer.
Collapse
Affiliation(s)
- Sachin R Kandalkar
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India; Department of Organic Chemistry, Andhra university, Visakhapatnam 530003, India
| | | | - Manoj Joshi
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Atul Wavhal
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Yogesh Waman
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Amol A Raje
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Ashwini Tambe
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Shariq Ansari
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Siddhartha De
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Venkata P Palle
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Kasim A Mookhtiar
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India
| | - Anil M Deshpande
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India.
| | - Dinesh A Barawkar
- Advinus Therapeutics Ltd., Drug Discovery Facility, Quantum Towers, Plot-9, Phase-I, Rajiv Gandhi Infotech Park, Hinjewadi, Pune 411 057, India.
| |
Collapse
|
2
|
Ni H, Li YH, Hao RL, Li H, Hu SQ, Li HH. Identification of adenosine deaminase inhibitors from Tofu wastewater and litchi peel and their synergistic anticancer and antibacterial activities with cordycepin. Int J Food Sci Technol 2016. [DOI: 10.1111/ijfs.13064] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- He Ni
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development; College of Life Science and Research and Development Center for Rare Animals; South China Normal University; Guangzhou 510631 China
| | - Yue-Hong Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development; College of Life Science and Research and Development Center for Rare Animals; South China Normal University; Guangzhou 510631 China
| | - Rui-Lin Hao
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development; College of Life Science and Research and Development Center for Rare Animals; South China Normal University; Guangzhou 510631 China
| | - Hui Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development; College of Life Science and Research and Development Center for Rare Animals; South China Normal University; Guangzhou 510631 China
- Guangzhou Huichuan Medical Technology Company; 211 Jinfu Building 90 Qifu Road Baiyun District Guangzhou 510410 China
| | - Song-Qing Hu
- Guangdong Provincial Key Laboratory of Green Processing Technology and Product Safety of Natural Products; College of Light Industry and Food Sciences; South China University of Technology; Guangzhou 510640 China
| | - Hai-Hang Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development; College of Life Science and Research and Development Center for Rare Animals; South China Normal University; Guangzhou 510631 China
| |
Collapse
|
3
|
Coi A, Tonelli M, Ganadu ML, Bianucci AM. Binding free energy calculations of adenosine deaminase inhibitors. Bioorg Med Chem 2006; 14:2636-41. [PMID: 16376548 DOI: 10.1016/j.bmc.2005.11.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Revised: 11/16/2005] [Accepted: 11/22/2005] [Indexed: 10/25/2022]
Abstract
The interactions between four inhibitors and adenosine deaminase (ADA) were examined by calculating their binding free energies after molecular dynamics simulations. A bonded model was used to represent the electrostatic potentials of the zinc coordination site. The charge distribution of the model was derived by using a two-stage electrostatic potential fitting calculations. The calculated binding free energies are in good agreement with the experimental data and the ranking of binding affinities is well reproduced. Notably, our findings suggest that non-polar contributions play an important role for ADA-inhibitor interactions.
Collapse
Affiliation(s)
- Alessio Coi
- Dipartimento di Scienze Farmaceutiche, Università di Pisa, 56126 Pisa, Italy
| | | | | | | |
Collapse
|
4
|
Paul MK, Grover V, Mukhopadhyay AK. Merits of HPLC-based method over spectrophotometric method for assessing the kinetics and inhibition of mammalian adenosine deaminase. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 822:146-53. [PMID: 15993664 DOI: 10.1016/j.jchromb.2005.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 06/01/2005] [Accepted: 06/03/2005] [Indexed: 10/25/2022]
Abstract
Measurement of adenosine deaminase (ADA) activity using spectrophotometric method presents problem, regarding the quantitative estimation of the substrate degradation and product formation, due to the closely apposed lambda(max) of the substrates, product and the inhibitor. The feasibility of applying reverse-phase HPLC technique, for studying adenosine deaminase-catalyzed reaction product and inhibition study was examined. We have drawn a comparison between the HPLC-based method over the corresponding spectrophotometric method. A gradient elution pattern was used to separate substrate (adenosine and deoxyadenosine), product (inosine and deoxyinosine) and standard adenosine deaminase inhibitor (erythro-9-(3-nonyl-p-aminobenzyl)-adenine) in the HPLC method. The product formation was quantitated by monitoring the absorbance at 260 nm with the progress of time. The limit of detection as well as the limit of quantification of the respective enzymatic product were found to be in nano molar (nM) range in the HPLC method. This study was also extended to monitor adenosine deaminase activity in different cancer cells of hematological origin. The HPLC-based method is found to be suitable for the quantitative estimation of adenosine deaminase-catalyzed reaction product and for studying inhibition mechanism of different inhibitors. The HPLC-based method has specific advantages over the spectrophotometric method. Moreover, the concentration of different nucleotides in cell lysate and body fluid can be measured using this HPLC method.
Collapse
Affiliation(s)
- Manash K Paul
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S Nagar, Mohali, Punjab 160062, India
| | | | | |
Collapse
|
5
|
Boess FG, Hendrix M, van der Staay FJ, Erb C, Schreiber R, van Staveren W, de Vente J, Prickaerts J, Blokland A, Koenig G. Inhibition of phosphodiesterase 2 increases neuronal cGMP, synaptic plasticity and memory performance. Neuropharmacology 2004; 47:1081-92. [PMID: 15555642 DOI: 10.1016/j.neuropharm.2004.07.040] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 06/02/2004] [Accepted: 07/28/2004] [Indexed: 10/25/2022]
Abstract
An essential element of the signalling cascade leading to synaptic plasticity is the intracellular second messenger molecule guanosine 3',5'-cyclic monophosphate (cGMP). Using the novel, potent, and selective inhibitor Bay 60-7550, we show that the enzyme 3',5'-cyclic nucleotide phosphodiesterase type 2 (PDE2) is responsible for the degradation of newly synthesized cGMP in cultured neurons and hippocampal slices. Inhibition of PDE2 enhanced long-term potentiation of synaptic transmission without altering basal synaptic transmission. Inhibition of PDE2 also improved the performance of rats in social and object recognition memory tasks, and reversed MK801-induced deficits in spontaneous alternation in mice in a T-maze. Our data provide strong evidence that inhibition of PDE2 can improve memory functions by enhancing neuronal plasticity.
Collapse
Affiliation(s)
- Frank G Boess
- Bayer Healthcare AG, Pharma Research CNS, 42096 Wuppertal-Elberfeld, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Cordero OJ, Salgado FJ, Fernández‐Alonso CM, Herrera C, Lluis C, Franco R, Nogueira M. Cytokines regulate membrane adenosine deaminase on human activated lymphocytes. J Leukoc Biol 2001. [DOI: 10.1189/jlb.70.6.920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Oscar J. Cordero
- Departments of Biochemistry and Molecular Biology, University of Santiago de Compostela, 15706 Santiago de Compostela
| | - Francisco J. Salgado
- Departments of Biochemistry and Molecular Biology, University of Santiago de Compostela, 15706 Santiago de Compostela
| | - Carmen M. Fernández‐Alonso
- Departments of Biochemistry and Molecular Biology, University of Santiago de Compostela, 15706 Santiago de Compostela
| | - Carolina Herrera
- Departments of Biochemistry and Molecular Biology, University of Barcelona, 08108 Barcelona, Spain
| | - Carmen Lluis
- Departments of Biochemistry and Molecular Biology, University of Barcelona, 08108 Barcelona, Spain
| | - Rafael Franco
- Departments of Biochemistry and Molecular Biology, University of Barcelona, 08108 Barcelona, Spain
| | - Montserrat Nogueira
- Departments of Biochemistry and Molecular Biology, University of Santiago de Compostela, 15706 Santiago de Compostela
| |
Collapse
|
7
|
Cristalli G, Costanzi S, Lambertucci C, Lupidi G, Vittori S, Volpini R, Camaioni E. Adenosine deaminase: functional implications and different classes of inhibitors. Med Res Rev 2001; 21:105-28. [PMID: 11223861 DOI: 10.1002/1098-1128(200103)21:2<105::aid-med1002>3.0.co;2-u] [Citation(s) in RCA: 211] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Adenosine deaminase (ADA) is an enzyme of the purine metabolism which catalyzes the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine, respectively. This ubiquitous enzyme has been found in a wide variety of microorganisms, plants, and invertebrates. In addition, it is present in all mammalian cells that play a central role in the differentiation and maturation of the lymphoid system. However, despite a number of studies performed to date, the physiological role played by ADA in the different tissues is not clear. Inherited ADA deficiency causes severe combined immunodeficiency disease (ADA-SCID), in which both B-cell and T-cell development is impaired. ADA-SCID has been the first disorder to be treated by gene therapy, using polyethylene glycol-modified bovine ADA (PEG-ADA). Conversely, there are several diseases in which the level of ADA is above normal. A number of ADA inhibitors have been designed and synthesized, classified as ground-state and transition-state inhibitors. They may be used to mimic the genetic deficiency of the enzyme, in lymphoproliferative disorders or immunosuppressive therapy (i.e., in graft rejection), to potentiate the effect of antileukemic or antiviral nucleosides, and, together with adenosine kinase, to reduce breakdown of adenosine in inflammation, hypertension, and ischemic injury.
Collapse
Affiliation(s)
- G Cristalli
- Dipartimento di Scienze Chimiche, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy.
| | | | | | | | | | | | | |
Collapse
|
8
|
Pragnacharyulu PV, Varkhedkar V, Curtis MA, Chang IF, Abushanab E. Adenosine deaminase inhibitors: synthesis and biological evaluation of unsaturated, aromatic, and oxo derivatives of (+)-erythro-9-(2'S-hydroxy-3'R-nonyl)adenine [(+)-EHNA]. J Med Chem 2000; 43:4694-700. [PMID: 11101360 DOI: 10.1021/jm0002533] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis and biological evaluation of three classes of chain-modified derivatives of (+)-EHNA are described. Among the 5', 6'-unsaturated derivatives, the Z-isomer was the most potent inhibitor of adenosine deaminase (ADA) but 3-fold less active than (+)-EHNA. Several 9-aralkyladenines (ARADs) have been prepared, and their inhibitory activity was determined. A minimum of two carbon atoms separating the aromatic ring from the adenine-bearing carbon (C-3') was found to be essential for ADA activity equal to or slightly greater than that of (+)-EHNA. Finally, replacement of the C-5' carbon with an oxygen resulted in reduced potency.
Collapse
Affiliation(s)
- P V Pragnacharyulu
- Department of Chemistry, University of Rhode Island, Kingston, Rhode Island 02881-0809, USA
| | | | | | | | | |
Collapse
|
9
|
Côté M, Payet MD, Rousseau E, Guillon G, Gallo-Payet N. Comparative involvement of cyclic nucleotide phosphodiesterases and adenylyl cyclase on adrenocorticotropin-induced increase of cyclic adenosine monophosphate in rat and human glomerulosa cells. Endocrinology 1999; 140:3594-601. [PMID: 10433216 DOI: 10.1210/endo.140.8.6889] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The present study investigated the role and identity of cyclic nucleotide phosphodiesterases (PDEs) in the regulation of basal and ACTH-stimulated levels of intracellular cAMP in human and rat adrenal glomerulosa cells. Comparative dose-response curves indicated that maximal hormone-stimulated cAMP accumulation was 11- and 24-fold higher in human and rat cells, compared with cAMP production obtained in corresponding membranes, respectively. Similarly to 3-isobutyl-1-methyl-xanthine, 25 microM erythro-9-[2-hydroxy-3-nonyl]adenine (EHNA, a specific PDE2 inhibitor), caused a large increase in ACTH-stimulated cAMP accumulation; by contrast, it did not change cAMP production in membranes. Moreover, in membrane fractions, addition of 10 microM cGMP inhibited ACTH-induced cAMP production, an effect completely reversed by addition of 25 microM EHNA. These results indicate that PDE2 activity is involved in the regulation of cAMP accumulation induced by ACTH, and suggest that ACTH inhibits this activity. Indeed, time-course studies indicated that ACTH induced a rapid decrease in cGMP production, resulting in PDE2 inhibition, which in turn, contributed [with adenylyl cyclase (AC) activation] to an accumulation in cAMP for 15 min. Thereafter, cAMP content decreased, because of cAMP-stimulated PDE2, as confirmed by measurement of PDE activity that was activated by ACTH, but only after a 10-min incubation. Hence, we demonstrate that the ACTH-induced increase in intracellular cAMP is the result of a balance between activation of AC and direct modulation of PDE2 activity, an effect mediated by cGMP content. Although similar results were observed in both models, PDE2 involvement is more important in rat than in human adrenal glomerulosa cells, whereas AC is more stimulated in human than in rat glomerulosa cells.
Collapse
Affiliation(s)
- M Côté
- Department of Medicine, Faculty of Medicine, University of Sherbrooke, Québec, Canada
| | | | | | | | | |
Collapse
|
10
|
Curtis MA, Varkhedkar V, Pragnacharyulu PV, Abushanab E. Adenosine deaminase inhibitors. Synthesis and biological evaluation of aralkyladenines (ARADS). Bioorg Med Chem Lett 1998; 8:1639-42. [PMID: 9873405 DOI: 10.1016/s0960-894x(98)00291-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Several 9-aralkyladenines have been prepared and their ADA inhibitory activity was determined. A minimum of two carbon atoms separating the aromatic ring from the adenine-bearing carbon (C3') was found essential for potent activity.
Collapse
Affiliation(s)
- M A Curtis
- Department of Biomedical Sciences, University of Rhode Island, Kingston 02881-0809, USA
| | | | | | | |
Collapse
|
11
|
Abstract
OBJECTIVES This study sought to investigate the myocardial mechanisms causing refractoriness to ischemic preconditioning in pigs. BACKGROUND Ischemic preconditioning in the pig vanishes after 60 min and cannot be reinstated by a second cycle of brief coronary occlusions at this time point. Ischemic preconditioning has been shown to be mediated by adenosine A1-receptors. Because myocardial adenosine production during ischemia ceases as the number of repeated brief ischemic episodes increases, we hypothesized that this lack of adenosine may cause this myocardial refractoriness. METHODS In open chest pigs, ischemic preconditioning was achieved by repeated brief coronary occlusions. Myocardial adenosine content was assessed by high performance liquid chromatographic analysis of serial myocardial biopsy samples; infarct size (percent infarcted area of the area at risk) was determined using tetrazolium salts. RESULTS Ischemic preconditioning by two cycles of occlusion of the left anterior descending coronary artery (10 min) and reperfusion (30 min) decreased infarct size ([mean +/- SEM] 40.4+/-2.9%; control: 76.9+/-1.8%, p < 0.001). Prolonging the second reperfusion period to 60 min caused ischemic preconditioning to vanish (79.0+/-0.5%) and caused refractoriness to a second cycle of preconditioning (70.0+/-2.0%). Myocardial adenosine content increased only during the first coronary occlusion (baseline: 110.9+/-42.0 nmol/g dry weight; first coronary occlusion: 1,686.2+/-244.1, p < 0.001) but not during subsequent coronary occlusions. In refractory myocardium, intramyocardial microinfusion of the adenosine A1-receptor agonist N6-cyclohexyladenosine (CHA [0.3 mmol/liter]) again decreased infarct size (27.4+/-7.0%, p < 0.001 vs. control). CONCLUSIONS Myocardial refractoriness may be caused by the inability to produce adenosine endogenously. In refractory myocardium, application of CHA reinduces cardioprotection.
Collapse
Affiliation(s)
- A M Vogt
- Max-Planck-Institute for Physiological and Clinical Research (W.G. Kerckhoff-Institute), Department of Experimental Cardiology, Bad Nauheim, Germany.
| | | | | | | |
Collapse
|
12
|
Pragnacharyulu PV, Lu PJ, Abushanab E. Adenosine deaminase inhibitors. Synthesis and biological evaluation of chain modified analogs of (+)-EHNA. Bioorg Med Chem Lett 1996. [DOI: 10.1016/0960-894x(96)00439-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
13
|
Xia Y, Khatchikian G, Zweier JL. Adenosine deaminase inhibition prevents free radical-mediated injury in the postischemic heart. J Biol Chem 1996; 271:10096-102. [PMID: 8626567 DOI: 10.1074/jbc.271.17.10096] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In the presence of its substrates hypoxanthine and xanthine, xanthine oxidase generates oxygen free radicals that cause postischemic injury. Recently, it has been demonstrated that the burst of xanthine oxidase-mediated free radical generation in the reperfused heart is triggered by a large increase in substrate formation, which occurs secondary to the degradation of adenine nucleotides during ischemia. It is not known, however, whether blocking this substrate formation is sufficient to prevent radical generation and functional injury. Therefore, studies were performed in isolated rat hearts in which xanthine oxidase substrate formation was blocked with the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), and measurements of contractile function and free radical generation were performed. Chromatographic measurements of the intracellular adenine nucleotide pool showed that preischemic administration of EHNA blocked postischemic hypoxanthine, xanthine, and inosine formation. Electron paramagnetic resonance spin trapping measurements of free radical generation showed that inhibition of adenosine deaminase with EHNA blocked free radical generation and that it also increased the recovery of contractile function by more than 2-fold. Exogenous infusion of hypoxanthine and xanthine totally reversed the protective effects of EHNA. These results demonstrate that blockade of xanthine oxidase substrate formation by adenosine deaminase inhibition can prevent free radical generation and contractile dysfunction in the postischemic heart.
Collapse
Affiliation(s)
- Y Xia
- Department of Medicine, Division of Cardiology, Johns Hopkins Medical Institutions, Johns Hopkins Bayview Medical Center, Baltimore, Maryland 21224, USA
| | | | | |
Collapse
|