76
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Ansari S, Prabhu D, Gujar R, Kanekar A, Rajeswari B, Kulkarni M, Murali M, Babu Y, Natarajan V, Rajeswari S, Suresh A, Manivannan R, Antony M, Srinivasan T, Manchanda V. Counter-current extraction of uranium and lanthanides from simulated high-level waste using N,N,N′,N′-tetraoctyl diglycolamide. Sep Purif Technol 2009. [DOI: 10.1016/j.seppur.2008.11.019] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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77
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Natarajan V, Rajeswari B, Dhawale BA, Hon NS, Godbole SV, Manchanda VK. Application of energy dispersive X-ray fluorescence for the determination of metallic impurities in ThO2. J Radioanal Nucl Chem 2009. [DOI: 10.1007/s10967-008-7384-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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78
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Sivalingam G, Natarajan V, Sarma KR, Parasuveera U. Solubility of Ethylene in the Presence of Hydrogen in Process Solvents under Polymerization Conditions. Ind Eng Chem Res 2008. [DOI: 10.1021/ie801236m] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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79
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Georas SN, Berdyshev E, Hubbard W, Gorshkova IA, Usatyuk PV, Saatian B, Myers AC, Williams MA, Xiao HQ, Liu M, Natarajan V. Lysophosphatidic acid is detectable in human bronchoalveolar lavage fluids at baseline and increased after segmental allergen challenge. Clin Exp Allergy 2007; 37:311-22. [PMID: 17359381 DOI: 10.1111/j.1365-2222.2006.02626.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Lysophosphatidic acid (LPA) is a biologically active lysophospholipid and a component of normal plasma. LPA binds to receptors expressed on circulating and structural lung cells and affects cell growth and activation. Whether LPA is present in the lung has not been previously reported. OBJECTIVE To develop an assay to measure LPA in bronchoalveolar lavage (BAL) fluids, and to study the association between LPA and allergic airway inflammation. METHODS Seventeen allergic subjects underwent bronchoscopy and segmental allergen challenge, followed 18 h later by BAL. Supernatants were analysed for LPA content using liquid chromatography and mass spectroscopy. Expression of LPA receptors on primary bronchial epithelial cells was analysed by immunolabelling, and the effects of LPA on epithelial cell barrier function was investigated by measuring transepithelial resistance. RESULTS LPA was detectable in BAL from control lung segments, and significantly increased 18 h after allergen challenge. Polyunsaturated species of LPA were especially increased following segmental allergen challenge. LPA levels did not strongly correlate with the number or percentages of eosinophils, neutrophils of lymphocytes, whereas MIP-3alpha (CCL20) levels correlated significantly with the allergen-driven influx of lymphocytes. The levels of LPA from control sites correlated inversely with BAL protein content, suggesting that LPA promoted epithelial barrier integrity at baseline. Experiments using primary human bronchial epithelial cells confirmed that LPA tightened the epithelial cell barrier. CONCLUSION Lysophosphatidic acid is detectable in human BAL fluids at baseline and its expression increases during allergic inflammation. LPA does not appear to be a dominant chemoattractant for eosinophils or lymphocytes during allergic airway inflammation. In the absence of ongoing inflammation, LPA may promote epithelial barrier integrity.
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80
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Dudek SM, Camp SM, Chiang ET, Singleton PA, Usatyuk PV, Zhao Y, Natarajan V, Garcia JGN. Pulmonary endothelial cell barrier enhancement by FTY720 does not require the S1P1 receptor. Cell Signal 2007; 19:1754-64. [PMID: 17475445 PMCID: PMC2682440 DOI: 10.1016/j.cellsig.2007.03.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 03/22/2007] [Accepted: 03/22/2007] [Indexed: 10/23/2022]
Abstract
Novel therapeutic strategies are needed to reverse the loss of endothelial cell (EC) barrier integrity that occurs during inflammatory disease states such as acute lung injury. We previously demonstrated potent EC barrier augmentation in vivo and in vitro by the platelet-derived phospholipid, sphingosine 1-phosphate (S1P) via ligation of the S1P1 receptor. The S1P analogue, FTY720, similarly exerts barrier-protective vascular effects via presumed S1P1 receptor ligation. We examined the role of the S1P1 receptor in sphingolipid-mediated human lung EC barrier enhancement. Both S1P and FTY-induced sustained, dose-dependent barrier enhancement, reflected by increases in transendothelial electrical resistance (TER), which was abolished by pertussis toxin indicating Gi-coupled receptor activation. FTY-mediated increases in TER exhibited significantly delayed onset and intensity relative to the S1P response. Reduction of S1P1R expression (via siRNA) attenuated S1P-induced TER elevations whereas the TER response to FTY was unaffected. Both S1P and FTY rapidly (within 5 min) induced S1P1R accumulation in membrane lipid rafts, but only S1P stimulated S1P1R phosphorylation on threonine residues. Inhibition of PI3 kinase activity attenuated S1P-mediated TER increases but failed to alter FTY-induced TER elevation. Finally, S1P, but not FTY, induced significant myosin light chain phosphorylation and dramatic actin cytoskeletal rearrangement whereas reduced expression of the cytoskeletal effectors, Rac1 and cortactin (via siRNA), attenuated S1P-, but not FTY-induced TER elevations. These results mechanistically characterize pulmonary vascular barrier regulation by FTY720, suggesting a novel barrier-enhancing pathway for modulating vascular permeability.
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81
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Burns MP, Pendyala S, Gorshkova IA, He D, Bear JE, Usatyuk PV, Natarajan V. 5 CORONIN 1B REGULATES HUMAN LUNG ENDOTHELIAL CELL GENERATION OF HYPEROXIA-INDUCED REACTIVE OXYGEN SPECIES. J Investig Med 2007. [DOI: 10.1136/jim-55-02-05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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82
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Kalari S, Zhao Y, Berdyshev E, Usatyuk PV, He D, Natarajan V. 47 ROLE OF ACYLGLYCEROL KINASE IN LYSOPHOSPHATIDIC ACID-INDUCED TRANSACTIVATION OF EPIDERMAL GROWTH FACTOR RECEPTOR AND EXPRESSION OF CYCLOOXYGENASE 2 AND INTERLEUKIN-8 IN PRIMARY HUMAN BRONCHIAL EPITHELIAL CELLS. J Investig Med 2007. [DOI: 10.1136/jim-55-02-47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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83
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Sammani S, Mirzapoiazova T, Moreno L, Proia R, Evenoski C, Moitra J, Natarajan V, Singleton P, Garcia JG. 88 EFFECT OF THE S1P1 GENE KO ON LIPOPOLYSACCHARIDE-INDUCED MURINE ACUTE LUNG INJURY. J Investig Med 2007. [DOI: 10.1136/jim-55-02-88] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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84
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Kalari S, Zhao Y, Berdyshev E, Usatyuk P, He D, Natarajan V. Role of Acylglycerol Kinase in Lysophosphatidic Acid–Induced Transactivation of Epidermal Growth Factor Receptor and Expression of Cyclooxygenase 2 and Interleukin-8 in Primary Human Bronchial Epithelial Cells. J Investig Med 2007. [DOI: 10.1177/108155890705500247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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85
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Zhao Y, He D, Stern R, Kalari S, Spannhake EW, Natarajan V. 71 LYSOPHOSPHATIDIC ACID INDUCES CYCLOOXYGENASE 2 EXPRESSION AND PROSTAGLANDIN E2 PRODUCTION IN HUMAN PRIMARY BRONCHIAL EPITHELIAL CELLS. J Investig Med 2007. [DOI: 10.1136/jim-55-02-71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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86
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Penzak SR, Kabuye G, Mugyenyi P, Mbamanya F, Natarajan V, Alfaro RM, Kityo C, Formentini E, Masur H. Cytochrome P450 2B6 (CYP2B6) G516T influences nevirapine plasma concentrations in HIV-infected patients in Uganda. HIV Med 2007; 8:86-91. [PMID: 17352764 DOI: 10.1111/j.1468-1293.2007.00432.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Polymorphisms in the cytochrome P450 (CYP) 2B6 gene have been shown to influence nevirapine plasma concentrations in HIV-infected European Caucasians. Although nevirapine is used extensively in Africa, the influence of CYP2B6 genotype on nevirapine exposure has not been assessed in this population. We aimed to determine the influence of CYP2B6 genotype at position 516 on nevirapine trough concentrations in HIV-infected patients in Kampala, Uganda. Additional polymorphisms in the CYP and multidrug resistance protein-1 (MDR-1) genes were also assessed for their impact on nevirapine concentrations. METHODS The following genotypes were determined in all subjects using polymerase chain reaction-restriction fragment length polymorphism: CYP2B6 G516T, MDR-1 C3435T and G2677T, CYP3A4(*)1B and CYP3A5(*)3. Nevirapine plasma concentrations were determined using high-performance liquid chromatography in 23 HIV-infected patients who were generally healthy and had been taking nevirapine 200 mg twice daily for at least 14 days. Analysis of variance with post hoc testing was used to compare nevirapine concentrations among CYP2B6 genotype groups. RESULTS The median nevirapine trough concentration in individuals homozygous for the variant allele (TT) was 7607 ng/mL vs 4181 and 5559 ng/mL for GG and GT individuals, respectively (GG vs TT median ratio=1.82; P=0.011). The mean ratio for TT vs GG individuals (95% confidence interval) was 1.51 (1.18, 1.84). No associations were observed between the other polymorphisms studied and nevirapine concentrations. CONCLUSIONS CYP2B6 G516T significantly influenced nevirapine trough concentrations in HIV-infected patients in Uganda. Additional studies in larger patient populations are necessary to further define the potential clinical impact of these preliminary findings.
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87
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Burns M, Pendyala S, Gorshkova I, He D, Bear J, Usatyuk P, Natarajan V. Coronin 1B Regulates Human Lung Endothelial Cell Generation of Hyperoxia-Induced Reactive Oxygen Species. J Investig Med 2007. [DOI: 10.1177/108155890705500205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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88
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Pendyala S, Gorshkova IA, He D, Cho H, Kleeberger SR, Natarajan V. 57 NRF2 REGULATES HYPEROXIA-MEDIATED NOX4 EXPRESSION AND REACTIVE OXYGEN SPECIES PRODUCTION. J Investig Med 2007. [DOI: 10.1136/jim-55-02-57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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89
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Zhao Y, He D, Stern R, Kalari S, Spannhake E, Natarajan V. Lysophosphatidic Acid Induces Cyclooxygenase 2 Expression and Prostaglandin E 2 Production in Human Primary Bronchial Epithelial Cells. J Investig Med 2007. [DOI: 10.1177/108155890705500271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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90
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Pendyala S, Gorshkova I, He D, Cho H, Kleeberger S, Natarajan V. Nrf2 Regulates Hyperoxia-Mediated Nox4 Expression and Reactive Oxygen Species Production. J Investig Med 2007. [DOI: 10.1177/108155890705500257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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91
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Sammani S, Mirzapoiazova T, Moreno L, Proia R, Evenoski C, Moitra J, Natarajan V, Singleton P, Garcia J. Effect of the S1P1 Gene Ko on Lipopolysaccharide-Induced Murine Acute Lung Injury. J Investig Med 2007. [DOI: 10.1177/108155890705500288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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92
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Abdellaoui A, Al-Daraji W, Natarajan V, Sandilands D. Spontaneous renal haemorrhage in the peritoneal cavity. Postgrad Med J 2006; 82:e14. [PMID: 16822913 PMCID: PMC2563760 DOI: 10.1136/pgmj.2005.044669] [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] [Indexed: 11/04/2022]
Abstract
A 49 year old woman was admitted to hospital after a sudden onset of severe back pain. Twelve hours later, the haemoglobin had decreased to 5.9 and became unstable. She underwent emergency laparotomy that showed intraperitoneal bleeding, secondary to spontaneous kidney rupture. The patient was given a nephrectomy. Histological examination showed an angiomyolipoma as the cause of the bleeding. To the knowledge of the authors, only five previous cases of spontaneous renal bleeding into the peritoneal cavity have been reported in English literature.
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93
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Mirzapoiazova T, Kolosova I, Usatyuk PV, Natarajan V, Verin AD. Diverse effects of vascular endothelial growth factor on human pulmonary endothelial barrier and migration. Am J Physiol Lung Cell Mol Physiol 2006; 291:L718-24. [PMID: 16679383 DOI: 10.1152/ajplung.00014.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Increased endothelial permeability is involved in the pathogenesis of many cardiovascular and pulmonary diseases. Vascular endothelial growth factor (VEGF) is a permeability-increasing cytokine. At the same time, VEGF is known to have a beneficial effect on endothelial cells (EC), increasing their survival. Pulmonary endothelium, particularly, may be exposed to higher VEGF concentrations, since the VEGF level is the higher in the lungs than in any other organ. The purpose of this work was to evaluate the effects of VEGF on barrier function and motility of cultured human pulmonary EC. Using transendothelial resistance measurements as an indicator of permeability, we found that 10 ng/ml VEGF significantly improved barrier properties of cultured human pulmonary artery EC (118.6+/-0.6% compared with 100% control, P<0.001). In contrast, challenge with 100 ng/ml VEGF decreased endothelial barrier (71.6+/-1.0% compared with 100% control, P<0.001) and caused disruption of adherens junctions. VEGF at both concentrations increased cellular migration; however, 10 ng/ml VEGF had a significantly stronger effect. VEGF caused a dose-dependent increase in intracellular Ca2+ concentration; however, phosphorylation of myosin light chain was detectably elevated only after treatment with 100 ng/ml. In contrast, 10 ng/ml but not 100 ng/ml VEGF caused a significant increase in intracellular cAMP (known barrier-protective stimulus) compared with nonstimulated cells (1,096+/-157 and 610+/-86 fmol/mg, respectively; P<0.024). Y576-specific phosphorylation of focal adhesion kinase was also stimulated by 10 ng/ml VEGF. Our data suggest that, depending on its concentration, VEGF may cause diverse effects on pulmonary endothelial permeability via different signaling pathways.
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94
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Ortiz AO, Natarajan V, Gregorius DR, Pollack S. Significantly reduced radiation exposure to operators during kyphoplasty and vertebroplasty procedures: methods and techniques. AJNR Am J Neuroradiol 2006; 27:989-94. [PMID: 16687529 PMCID: PMC7975715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND PURPOSE Vertebroplasty and kyphoplasty can be associated with significant radiation exposure to the operator. We compared the exposure levels to an operator performing vertebral fracture augmentation with vertebroplasty and kyphoplasty, to assess a cement injection and a monitoring technique designed to reduce this exposure. METHODS A neuroradiologist performed 189 consecutive vertebral augmentation procedures in 135 patients with osteoporotic compression fractures by using a bilateral approach with biplane pulse fluoroscopy at 7.5 pulses/second. Cement delivery was performed with intermittent fluoroscopy with kyphoplasty and vertebroplasty by using syringes or continuous fluoroscopic monitoring with a cement delivery system (CDS). Data collection included time and operator exposure parameters. RESULTS A total of 87 kyphoplasty procedures, 82 vertebroplasty procedures with a CDS (VP-CDS), and 20 vertebroplasty procedures with syringes (VP-S) were safely performed. Mean fluoroscopy time for device positioning was 4.3 minutes for each procedure type. Mean fluoroscopy time (minutes) for cement delivery was significantly different for the 3 procedure types; 2.1 for kyphoplasty, 3.7 for VP-CDS, and 1.5 for VP-S (P < .0001). Comparable mean radiation exposure rates (microsieverts/minute) were 0.8 for kyphoplasty, 1.1 for VP-CDS, and 0.3 for VP-S during device-positioning and 1.7 for kyphoplasty, 2.9 for VP-CDS, and 0.2 for VP-S during cement injection (P < .002). CONCLUSION Use of the modified cement injection technique and intermittent fluoroscopy with kyphoplasty and vertebroplasty with syringes results in a significantly lower operator exposure rate compared with vertebroplasty with a CDS.
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95
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Usatyuk P, Natarajan V. Regulation of 4-Hydroxy-2-Nonenal-Mediated Endothelial Barrier Function by Focal Adhesion and Adherens Junction Proteins. J Investig Med 2006. [DOI: 10.1177/108155890605402s45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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96
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Chatchavalvanich S, Nonas S, Miller I, Kawkitinarong K, Gorshkova I, Bochkov V, Leitinger N, Natarajan V, Garcia J, Birukov K. Oxidized Phospholipids Reduce Vascular Leak and Inflammation in a Rat Model of Acute Lung Injury. J Investig Med 2006. [DOI: 10.1177/108155890605402s18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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97
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Pendyala S, Gorshkova I, Gorshko B, Donghong H, Stern RK, Usatyuk P, Natarajan V. 38 NOX4, A HOMOLOGUE OF NOX2, REGULATES HYPEROXIA-INDUCED REACTIVE OXYGEN SPECIES PRODUCTION AND ANGIOGENESIS IN HUMAN LUNG ENDOTHELIAL CELLS. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0015.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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98
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Zhao Y, He D, Zhao J, Spannhake E, Leff A, Natarajan V. Lysophosphatidic Acid Induces Interleukin-13 Receptor α2 Expression and Secretion and Down-Regulates Interleukin-13 Signaling in Human Bronchial Epithelial Primary Cells. J Investig Med 2006. [DOI: 10.1177/108155890605402s79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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99
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Pendyala S, Gorshkova I, Gorshko B, Donghong H, Stern R, Usatyuk P, Natarajan V. Nox4, a Homologue of Nox2, Regulates Hyperoxia-Induced Reactive Oxygen Species Production and Angiogenesis in Human Lung Endothelial Cells. J Investig Med 2006. [DOI: 10.1177/108155890605402s38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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100
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Gorshkova I, Berdyshev E, Saatian B, Zhao Y, Pendyala S, Garcia JG, Natarajan V. 22 SPHINGOSINE-1-PHOSPHATE-MEDIATED ENDOTHELIAL CELL MOTILITY IS REGULATED BY S1P1 RECEPTOR, LIPID PHOSPHATE PHOSPHATASE-1, AND SPHINGOSINE KINASE 1. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0015.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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