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Khoury J, Kirkpatrick SR, Kodali GC, Svrluga RC, Tarrant LJB. Gas Cluster Ion Beam (GCIB) surface modification of titanium enhances osteoblast proliferation and bone formation
in vitro. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.638.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Liu J, Ibla JC, Liu Q, Li J, Han X, Khoury J. Disrupted in schizophrenia 1 (DISC1) regulates ATM‐mediated NFκB activation during hypoxia and reoxygenation (H/R). FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.lb662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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78
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Khoury J, Kodali GC, Tarrant LJB, Svrluga RC, Kirkpatrick SR. Surface modification by Gas Cluster Ion Beam (GCIB) as a novel drug delivery method for vascular stents. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.644.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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79
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McClure R, Khoury J, Feldman A, Ketterling R. Clonal relationship between precursor B-cell acute lymphoblastic leukemia and histiocytic sarcoma: a case report and discussion in the context of similar cases. Leuk Res 2009; 34:e71-3. [PMID: 19744706 DOI: 10.1016/j.leukres.2009.08.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 08/13/2009] [Accepted: 08/17/2009] [Indexed: 11/16/2022]
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Estrov Z, Cortes J, Borthakur G, Faderl S, Garcia Manero G, Ravandi F, Khoury J, Ptaszynski M, Kantarjian H. A phase I dose-escalation study of the novel KSP inhibitor ARRY-520 in advanced leukemias. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.7022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
7022 ARRY-520 is a potent, selective KSP inhibitor that arrests cells in mitosis with the subsequent onset of apoptosis. ARRY-520 has shown potent activity in preclinical models of hematological cancers and is being evaluated in a phase I trial in patients with advanced or refractory leukemias. The primary objectives of this study are to establish the safety and the MTD of ARRY-520 given as a single dose each cycle. Secondary objectives are to characterize the pharmacokinetics (PK) of ARRY-520, to assess evidence of preliminary clinical activity, and to explore biomarkers of KSP inhibition. ARRY-520 is administered as a 1-h IV infusion as a single dose per cycle in a “3 + 3 phase I design”. Dose escalations are following a prespecified schema. PK analyses for ARRY-520 are performed on plasma samples collected during cycle 1 and cycle 2. Pretreatment and post-treatment peripheral blood samples are collected for analysis of markers of KSP activity. To date, 15 patients, with a median age of 69 yrs (range 44–84 yrs), have been enrolled in the single dose schedule, 3 patients each at doses of 2.5 mg/m2, 3.75 mg/m2, and 5.6 mg/m2 and 6 patients at 4.5 mg/m2 per cycle. All patients had disease refractory to, and/or relapsed from, 1 or more prior therapies with a median of 3 prior regimens (range 1–10). Two patients at 5.6 mg/m2 experienced a DLT of gr3 mucositis. ARRY-520 was well tolerated at doses below 5.6 mg/m2. 4.5 mg/m2 has been determined to be the MTD. ARRY-520 has shown promising signs of clinical activity at doses of 3.75 mg/m2 and above. 2 patients had a complete reduction in their peripheral blasts on day 5 of cycle 1. Of these, one patient experienced a 70% reduction in bone marrow blasts while on study. One patient without peripheral blood blasts at baseline had a 43% reduction in bone marrow blasts and four additional patients had marked reductions in WBC counts. This is the first reported use of a KSP inhibitor in refractory and/or relapsed leukemias. ARRY-520 has been well tolerated in patients on a single dose schedule. Mucositis was observed as the DLT at 5.6 mg/m2. At doses 3.75 mg/m2 and above, ARRY-520 has shown signs of clinical activity. Based on these data, an alternative dose schedule is being explored. Updated data including safety, PK, PD, and preliminary activity of ARRY 520 from this study will be presented. [Table: see text]
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Woo D, Khoury J, Haverbusch MM, Sekar P, Flaherty ML, Kleindorfer DO, Kissela BM, Moomaw CJ, Deka R, Broderick JP. Smoking and family history and risk of aneurysmal subarachnoid hemorrhage. Neurology 2009; 72:69-72. [PMID: 19122033 DOI: 10.1212/01.wnl.0000338567.90260.46] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Smoking and family history of aneurysmal subarachnoid hemorrhage (aSAH) are independent risk factors for aSAH. Using a population-based case-control study of hemorrhagic stroke, we hypothesized that having both a first-degree relative with a brain aneurysm or SAH (+FH) and current smoking interact to increase the risk of aSAH. METHODS Cases of aneurysmal SAH were prospectively recruited from all 17 hospitals in the five-county region around the University of Cincinnati. Controls were identified by random digit dialing. Controls were matched to cases of aSAH by age (+/-5 years), race, and sex. Conditional multiple logistic regression was used to identify independent risk factors. For deviation from the additive model, the interaction constant ratio test was used. RESULTS A total of 339 cases of aSAH were matched to 1,016 controls. Compared to current nonsmokers with no first-degree relatives with aSAH (-FH), the odds ratio (OR) for aSAH for current nonsmokers with +FH was 2.5 (95% confidence interval [CI] 0.9-6.9); for current smokers with -FH, OR = 3.1 (95% CI 2.2-4.4); and for current smokers with +FH, OR = 6.4 (95% CI 3.1-13. 2). The interaction constant ratio, which measured the deviation from the additive model, was significant: 2.19 (95% CI 0.80-5.99). The lower bound of the 95% CI >0.5 signifies a departure from the additive model. CONCLUSION Evidence of a gene-environment interaction with smoking exists for aneurysmal subarachnoid hemorrhage. This finding is important to counseling family members and for screening of intracranial aneurysm (IA) as well as the design and interpretation of genetic epidemiology of IA studies.
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Gollard R, Khoury J. Images in HIV/AIDS. HIV and myelodysplasia. THE AIDS READER 2009; 19:156-157. [PMID: 19388183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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Liu Q, Li J, Khoury J, Colgan SP, Ibla JC. Adenosine signaling mediates SUMO-1 modification of IkappaBalpha during hypoxia and reoxygenation. J Biol Chem 2009; 284:13686-13695. [PMID: 19297320 DOI: 10.1074/jbc.m809275200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Small ubiquitin-like modifier 1 (SUMO-1) modification of IkappaBalpha has been described to actively participate in NFkappaB regulation. Following proteosomal degradation of IkappaBalpha, an auto-regulatory loop consisting of transcriptional activation of IkappaBalpha gene and SUMO-1 modification of newly synthesized IkappaBalpha proceeds. The SUMOylated IkappaBalpha form is resistant to signal-induced degradation, consequently halting NFkappaB activation. We describe a mechanistic model by which adenosine (Ado) signaling results in significant accumulation of SUMO-1 modified IkappaBalpha with subsequent attenuation of NFkappaB activation. Using models of hypoxia followed by reoxygenation (H/R), we have documented an H/R cycle-dependent increase in extracellular Ado correlating with increases in the cytoplasmic pool of IkappaBalpha/SUMO-1. We demonstrate a dose-dependent increase in IkappaBalpha/SUMO in cells treated with the general Ado receptor agonist NECA and abolished by Ado receptor antagonists. Experiments in cells exposed to cycles of H/R followed by hypoxia demonstrated differential patterns of SUMOylation and phosphorylation of IkappaBalpha, greatly impacting its proteosomal degradation by the 26 S proteasome. Assays targeting knockdown and overexpression of SUMO-1 demonstrated significant regulation of NFkappaB activation and NFkappaB-mediated gene transcription (interleukin-6). These results were confirmed in vivo using wild type and cd73 null mouse lung tissue. In summary, we present an endogenous mechanism by which cells and tissues acquire anti-inflammatory properties by recruiting a nondegradable form of IkappaBalpha, a major control point for NFkappaB activation via Ado signaling.
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Neale G, Su X, Morton CL, Phelps D, Gorlick R, Lock RB, Reynolds CP, Maris JM, Friedman HS, Dome J, Khoury J, Triche TJ, Seeger RC, Gilbertson R, Khan J, Smith MA, Houghton PJ. Molecular characterization of the pediatric preclinical testing panel. Clin Cancer Res 2008; 14:4572-83. [PMID: 18628472 DOI: 10.1158/1078-0432.ccr-07-5090] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Identifying novel therapeutic agents for the treatment of childhood cancers requires preclinical models that recapitulate the molecular characteristics of their respective clinical histotypes. EXPERIMENTAL DESIGN AND RESULTS Here, we have applied Affymetrix HG-U133Plus2 profiling to an expanded panel of models in the Pediatric Preclinical Testing Program. Profiling led to exclusion of two tumor lines that were of mouse origin and five osteosarcoma lines that did not cluster with human or xenograft osteosarcoma samples. We compared expression profiles of the remaining 87 models with profiles from 112 clinical samples representing the same histologies and show that model tumors cluster with the appropriate clinical histotype, once "immunosurveillance" genes (contributed by infiltrating immune cells in clinical samples) are eliminated from the analysis. Analysis of copy number alterations using the Affymetrix 100K single nucleotide polymorphism GeneChip showed that the models have similar copy number alterations to their clinical counterparts. Several consistent copy number changes not reported previously were found (e.g., gain at 22q11.21 that was observed in 5 of 7 glioblastoma samples, loss at 16q22.3 that was observed in 5 of 9 Ewing's sarcoma and 4 of 12 rhabdomyosarcoma models, and amplification of 21q22.3 that was observed in 5 of 7 osteosarcoma models). We then asked whether changes in copy number were reflected by coordinate changes in gene expression. We identified 493 copy number-altered genes that are nonrandom and appear to identify histotype-specific programs of genetic alterations. CONCLUSIONS These data indicate that the preclinical models accurately recapitulate expression profiles and genetic alterations common to childhood cancer, supporting their value in drug development.
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Abstract
BACKGROUND Few data exist on the effect of maternal depression on child injury outcomes and mediators of this relationship. OBJECTIVE To examine the relationship between mothers' depressive symptoms and medically attended injuries in their children and the potential mediating role of child behavior. DESIGN/METHODS A cohort of mother-child dyads from the National Longitudinal Study of Youth followed from 1992 to 1994. The primary exposure variable was maternal depressive symptoms as measured by the Center for Epidemiologic Studies Depression Scale in 1992. Child behavior was assessed by the Behavior Problems Index externalizing subscale. Logistic regression was used to examine the relationship between depressive symptoms, child behavior, and injury reported in the prior year in 1994. RESULTS 94 medically attended injuries were reported in the 1106 children (8.5%); two-thirds were sustained in the home environment. Maternal depressive symptoms significantly increased the risk of child injury; injury risk increased 4% for every 1-point increase in depressive symptoms (adjusted OR 1.04, 95% CI 1.01 to 1.08, p=0.02). Increasing maternal depressive symptoms also increased the risk of externalizing behavior problems (adjusted OR 1.06, 95% CI 1.03 to 1.09), but externalizing behavior problems did not significantly mediate the relationship between maternal symptoms and child injury. CONCLUSIONS Increasing depressive symptoms in mothers was associated with an increased risk of child injury. Child behavior did not significantly mediate the association between maternal depressive symptoms and child injury in this cohort. Greater recognition, referral, and treatment of depressive symptoms in mothers may have effects on child behavior and injury risk.
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Mahajan V, Minshew PT, Khoury J, Shu PP, Muzaffar M, Abruzzo T, Leach JL, Tomsick TA. Eye position information on CT increases the identification of acute ischemic hypoattenuation. AJNR Am J Neuroradiol 2008; 29:1144-6. [PMID: 18356473 DOI: 10.3174/ajnr.a0995] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE It is possible that identification of eye deviation may sensitize a scan reader to early brain hypodensity associated with an arterial occlusive process. Our aim was to investigate the value of observing eye deviation on blinded CT identification of early hypoattenuation following ischemic infarct. MATERIALS AND METHODS Two staff and 2 fellow neuroradiologists reviewed 75 brain CT scans obtained within 3 hours of acute ischemia from subjects in the Interventional Management of Stroke Study. Films were reviewed 3 months apart, the first time with tape over the eyes on the images, the second with the eyes visible. Readers were asked if early hypoattenuation in the middle cerebral artery (MCA) distribution or if a hyperattenuated MCA was present. kappa statistics were calculated to determine agreement among the 4 readers and between each of the 2 readings by the same reader, not only for the original interpretation of the blinded study neuroradiologist but also for the Alberta Stroke Program Early CT Score (ASPECTS) for each subject assigned by an unblinded expert panel. A generalized estimating equations modeling approach was used to look at the overall effect of including eye information for agreement between interpretations. RESULTS Eye information availability was associated with improved agreement for detection of early ischemic hypoattenuation not only among the 4 readers but also between the 4 readers and both the blinded study neuroradiologist (P = .02) and the unblinded expert ASPECTS panel. When comparing first and second readings for hypoattenuation, we also noted increased mean values for sensitivity (46.8% first, 56.5% second), specificity (78.2%, 80.2%), positive predictive value (72.0%, 80.7%), negative predictive value (55.5%, 61.0%), and percentage agreement (61.0%, 67.5%). CONCLUSION Observation of CT eye deviation significantly improves reader identification of acute ischemic hypoattenuation.
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Khoury J, Geuss LR, Shortkroff S, Berlowitz Tarrant LJ. In vitro migration of mesenchymal stem cells (MSC) promotes differentiation to chondrocytes. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.522.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Tomsick T, Broderick J, Carrozella J, Khatri P, Hill M, Palesch Y, Khoury J. Revascularization results in the Interventional Management of Stroke II trial. AJNR Am J Neuroradiol 2008; 29:582-7. [PMID: 18337393 DOI: 10.3174/ajnr.a0843] [Citation(s) in RCA: 295] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Our aim was to detail revascularization results, including impact on outcome and mortality, in the Interventional Management of Stroke (IMS) II trial. MATERIALS AND METHODS IMS II was designed to obtain estimates of the efficacy and safety of reduced-dose intravenous recombinant tissue plasminogen activator (rtPA) followed by additional intra-arterial rtPA and low-energy sonography via the EKOS Primo Micro-Infusion Catheter at the occlusion in selected patients with ischemic stroke treated within 3 hours of onset. Revascularization outcomes were detailed and compared with modified Rankin Scale scores 0-2, mortality outcomes, and results from IMS I. RESULTS Complete recanalization at 60 minutes occurred in 12 of 29 (41.4%) sonography microcatheter-treated occlusions. Complete recanalization was achieved at 2 hours or procedure end in 20/29 (68.9%) in the ultrasound catheter-treated group, and final thrombolysis in cerebral infarction (TICI) 2/3 reperfusion was achieved in 18/29 (62.0%) ultrasound-treated subjects. Fifteen-minute angiograms demonstrated some recanalization in 69/145 (46.7%) sonography microcatheter treatment intervals, compared with 39/111 (35.1%) in IMS I treatments in 23 subjects with reliable 15-minute angiograms (P = .046). Pooled IMS I-II data demonstrated that partial or complete recanalization occurred in 56/75 (74.6%) and good reperfusion (TICI 2/3) occurred in 46/75 (61.3%) of internal carotid artery T and M1 occlusions. Revascularization correlated with good outcome for TICI 2/3 reperfusion (P = .0004), TICI 2B/3 reperfusion (P = .0002), and arterial occlusive lesion 2/3 recanalization (P = .03). CONCLUSION IMS II provides evidence that the EKOS Primo sonography microcatheter exhibits a trend toward improved recanalization of the occlusion compared with a standard microcatheter and again confirms the correlation between recanalization and reperfusion with good clinical outcome and reduced mortality.
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Khoury J, Pang M, Young C, Pandit A, Carr S, Fischer D, Stahl J. Cyanide generation during preservation of chlorinated wastewater effluent samples for total cyanide analysis. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2008; 80:53-59. [PMID: 18254399 DOI: 10.2175/106143007x220743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Dechlorinating agents and pH adjustment are often used to preserve wastewater samples for cyanide analysis. The effects of four approved preservation protocols on the results of the total cyanide analysis of effluents from four water reclamation plants were examined. The results differed widely, and a clear pattern emerged. Immediate analysis without pH adjustment generally gave total cyanide concentrations below the reporting limit of 5 microg/L, irrespective of the dechlorinating agents used. When the pH was adjusted to > or =12, a slight increase in the measured total cyanide concentration was observed when thiosulfate was used to dechlorinate the samples, and a significant increase (>10 microg/L) was observed when arsenite was used as the dechlorinating agent. These results provide evidence that approved preservation protocols may give rise to cyanide formation in chlorinated wastewater effluent matrices.
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Eckle T, Füllbier L, Wehrmann M, Khoury J, Mittelbronn M, Ibla J, Rosenberger P, Eltzschig HK. Identification of ectonucleotidases CD39 and CD73 in innate protection during acute lung injury. THE JOURNAL OF IMMUNOLOGY 2007; 178:8127-37. [PMID: 17548651 DOI: 10.4049/jimmunol.178.12.8127] [Citation(s) in RCA: 218] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Acute lung injury (ALI), such as that which occurs with mechanical ventilation, contributes to morbidity and mortality of critical illness. Nonetheless, in many instances, ALI resolves spontaneously through unknown mechanisms. Therefore, we hypothesized the presence of innate adaptive pathways to protect the lungs during mechanical ventilation. In this study, we used ventilator-induced lung injury as a model to identify endogenous mechanisms of lung protection. Initial in vitro studies revealed that supernatants from stretch-induced injury contained a stable factor which diminished endothelial leakage. This factor was subsequently identified as adenosine. Additional studies in vivo revealed prominent increases in pulmonary adenosine levels with mechanical ventilation. Because ectoapyrase (CD39) and ecto-5'-nucleotidase (CD73) are rate limiting for extracellular adenosine generation, we examined their contribution to ALI. In fact, both pulmonary CD39 and CD73 are induced by mechanical ventilation. Moreover, we observed pressure- and time-dependent increases in pulmonary edema and inflammation in ventilated cd39(-/-) mice. Similarly, pharmacological inhibition or targeted gene deletion of cd73 was associated with increased symptom severity of ventilator-induced ALI. Reconstitution of cd39(-/-) or cd73(-/-) mice with soluble apyrase or 5'-nucleotidase, respectively, reversed such increases. In addition, ALI was significantly attenuated and survival improved after i.p. treatment of wild-type mice with soluble apyrase or 5'-nucleotidase. Taken together, these data reveal a previously unrecognized role for CD39 and CD73 in lung protection and suggest treatment with their soluble compounds as a therapeutic strategy for noninfectious ALI.
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Khoury J, Henriksen T, Seljeflot I, Mørkrid L, Frøslie KF, Tonstad S. Effects of an antiatherogenic diet during pregnancy on markers of maternal and fetal endothelial activation and inflammation: the CARRDIP study. BJOG 2007; 114:279-88. [PMID: 17217362 PMCID: PMC1974834 DOI: 10.1111/j.1471-0528.2006.01187.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Objective To study the effect of an antiatherogenic diet on maternal and cord blood concentrations of systemic biomarkers of endothelial cell activation, haemostasis and inflammation. Design Single blinded randomised controlled clinical trial. Setting Obstetric outpatient clinic and maternity unit of a university hospital in Norway. Population Nonsmoking pregnant women aged 21–38 years carrying a single fetus and with no previous pregnancy-related complications. Methods Subjects (n = 290) were randomised to continue their usual diet or to adopt a diet low in saturated fat and cholesterol from gestational week 17–20 to birth. Soluble forms of cellular adhesion molecules, high-sensitivity C-reactive protein (CRP) and haemostatic markers were measured at 17–20 weeks of gestation (baseline) and subsequently up to week 36. All the above, except CRP, were also measured in cord blood. Main outcome measures Concentrations of maternal and fetal biomarkers and maternal CRP. Results All biomarkers except CRP levels increased significantly during the study period in both the intervention and control groups. None of the maternal or fetal biomarkers were influenced by the intervention (P > 0.05) except for a tendency to lower concentrations of cord blood tissue plasminogen activator antigen in the intervention group compared with the control group, median (interquartile range) 5.4 ng/ml (3.1–7.7) versus 5.8 ng/ml (3.5–11.8), P = 0.05. Conclusion An antiatherogenic diet in pregnancy did not significantly influence maternal or fetal blood concentrations of a range of biomarkers for inflammation. Thus, the previously reported effects of a cholesterol-lowering diet on maternal lipid profile and preterm delivery (<37 complete weeks of gestation) do not seem to involve changes in the systemic inflammatory responses of pregnancy.
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Rosenberger P, Khoury J, Kong T, Weissmüller T, Robinson AM, Colgan SP. Identification of vasodilator-stimulated phosphoprotein (VASP) as an HIF-regulated tissue permeability factor during hypoxia. FASEB J 2007; 21:2613-21. [PMID: 17412998 PMCID: PMC4049288 DOI: 10.1096/fj.06-8004com] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Increased tissue permeability is commonly associated with hypoxia of many origins. Since hypoxia-inducible factor (HIF) represents a predominant hypoxia signaling mechanism, we compared hypoxia-elicited changes in tissue barrier function in mice conditionally lacking intestinal epithelial hypoxia-inducible factor-1alpha (hif1a). Somewhat surprisingly, these studies revealed that mutant hif1a mice were protected from hypoxia-induced increases in intestinal permeability in vivo. Guided by microarray analysis of tissues derived from these mutant hif1a mice, we identified HIF-1-dependent repression of vasodilator-stimulated phosphoprotein (VASP), a molecule known to be important in the control of cytoskeletal dynamics, including barrier function. Studies at the mRNA and protein level confirmed hypoxia-elicited repression of VASP in murine tissue, cultured epithelia and endothelia, as well as human saphenous vein ex vivo. Targeted repression of VASP by siRNA recapitulated our findings with hypoxia and directed overexpression of VASP abolished hypoxia-induced barrier dysfunction. Studies in the cloned human VASP promoter revealed hypoxia-dependent transcriptional repression, and functional studies by chromatin immunoprecipitation (ChIP) and site-directed mutagenesis revealed hypoxia-dependent binding of HIF-1alpha to the human VASP promoter. These studies identify HIF-1-dependent repression of VASP as a control point for hypoxia-regulated barrier dysfunction.
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Khoury J, Ibla JC, Neish AS, Colgan SP. Identification of molecular anti‐inflammatory mechanisms of adenosine: Cullin‐1 deneddylation during hypoxic preconditioning (HPC). FASEB J 2007. [DOI: 10.1096/fasebj.21.5.a131-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Khoury J, Ibla JC, Neish AS, Colgan SP. Antiinflammatory adaptation to hypoxia through adenosine-mediated cullin-1 deneddylation. J Clin Invest 2007; 117:703-11. [PMID: 17318263 PMCID: PMC1797604 DOI: 10.1172/jci30049] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2006] [Accepted: 01/02/2007] [Indexed: 01/03/2023] Open
Abstract
A major adaptive pathway for hypoxia is hypoxic preconditioning (HPC), a form of endogenous protection that renders cells tolerant to severe challenges of hypoxia. We sought to define the antiinflammatory properties of HPC. cDNA microarray analysis of lung tissue from mice subjected to hypoxia or HPC identified a cluster of NF-kappaB-regulated genes whose expression is attenuated by HPC. Studies using an NF-kappaB luciferase reporter assay confirmed a significant suppression of NF-kappaB activation during HPC. HPC-elicited activity was conferrable, as a soluble supernatant from HPC-treated cells, and the active fraction was purified and identified as adenosine (Ado). Guided by recent studies demonstrating bacterial inhibition of NF-kappaB through cullin-1 (Cul-1) deneddylation, we found a dose-dependent deneddylation of Cul-1 by Ado receptor stimulation predominantly mediated by the Ado A2B receptor subtype. Further, siRNA-mediated repression of CSN5, a subunit of the COP9 signalosome responsible for deneddylation of Cul-1, partially reversed HPC-mediated inhibition of NF-kappaB. Cul-1 deneddylation was evident in a murine model of HPC and lost in animals lacking extracellular Ado (Cd73-/- mice). Taken together, these results demonstrate that HPC induces extracellular accumulation of Ado and suppresses NF-kappaB activity through deneddylation of Cul-1. These results define a molecular regulatory pathway by which Ado provides potent antiinflammatory properties.
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Iversen P, Khoury J, Sandset P, Seljeflot I, Ose L, Tonstad S, Henriksen T, Retterstøl K, Amundsen Å. 38 Development of a procoagulant pattern during pregnancy among women with familial hypercholesterolemia. Thromb Res 2007. [DOI: 10.1016/s0049-3848(07)70083-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ibla JC, Khoury J. Methods to assess tissue permeability. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2006; 341:111-7. [PMID: 16799193 DOI: 10.1385/1-59745-113-4:111] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
An essential requirement for adequate organ performance is the formation of permeability barriers that separate and maintain compartments of distinctive structure. The endothelial cell lining of the vasculature defines a semipermeable barrier between the blood and the interstitial spaces of all organs. Disruption of the endothelial cell barrier can result in increased permeability and vascular leak. These effects are associated with multiple systemic disease states. The mechanisms that control barrier function are complex and their full understanding requires a multidisciplinary approach. In vivo permeability data often complement molecular findings and add power to the studies. The interaction of multiple cell types and tissues present only on mammalian models allow for testing of hypothesis and to establish the physiological significance of the results. In this chapter, we describe methods that can be used systematically to measure the permeability characteristics of several organs.
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Baker E, Khoury J, Dietrich K, Kahn J, Martin J, Lanphear B. Attitudes and Practices of NIH-Funded Researchers About Reporting Individual Test Results to Research Subjects. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s125-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Haji-Saeed B, Sengupta SK, Testorf M, Goodhue W, Khoury J, Woods CL, Kierstead J. Real-time holographic deconvolution techniques for one-way image transmission through an aberrating medium: characterization, modeling, and measurements. APPLIED OPTICS 2006; 45:3298-306. [PMID: 16676035 DOI: 10.1364/ao.45.003298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We propose and demonstrate a new photorefractive real-time holographic deconvolution technique for adaptive one-way image transmission through aberrating media by means of four-wave mixing. In contrast with earlier methods, which typically required various codings of the exact phase or two-way image transmission for correcting phase distortion, our technique relies on one-way image transmission through the use of exact phase information. Our technique can simultaneously correct both amplitude and phase distortions. We include several forms of image degradation, various test cases, and experimental results. We characterize the performance as a function of the input beam ratios for four metrics: signal-to-noise ratio, normalized root-mean-square error, edge restoration, and peak-to-total energy ratio. In our characterization we use false-color graphic images to display the best beam-intensity ratio two-dimensional region(s) for each of these metrics. Test cases are simulated at the optimal values of the beam-intensity ratios. We demonstrate our results through both experiment and computer simulation.
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Haji-Saeed B, Kolluru R, Pyburn D, Leon R, Sengupta SK, Testorf M, Goodhue W, Khoury J, Drehman A, Woods CL, Kierstead J. Photoconductive optically driven deformable membrane under high-frequency bias: fabrication, characterization, and modeling. APPLIED OPTICS 2006; 45:3226-36. [PMID: 16676026 DOI: 10.1364/ao.45.003226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The fabrication and characterization of an optically addressable deformable mirror for a spatial light modulator are described. Device operation utilizes an electrostatically driven pixelated aluminized polymeric membrane mirror supported above an optically controlled photoconductive GaAs substrate. A 5 mum thick grid of patterned photoresist supports the 2 mum thick aluminized Mylar membrane. A conductive ZnO layer is placed on the backside of the GaAs wafer. Similar devices were also fabricated with InP. A standard Michelson interferometer is used to measure mirror deformation data as a function of illumination, applied voltage, and frequency. The device operates as an impedance distribution between two cascaded impedances of deformable membrane substrate, substrate, and electrode. An analysis of device's operation under several bias conditions, which relates membrane deformation to operating parameters, is presented.
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Ibla JC, Khoury J, Kong T, Robinson A, Colgan SP. Transcriptional repression of Na-K-2Cl cotransporter NKCC1 by hypoxia-inducible factor-1. Am J Physiol Cell Physiol 2006; 291:C282-9. [PMID: 16571862 DOI: 10.1152/ajpcell.00564.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Tissue edema is commonly associated with hypoxia. Generally, such episodes of fluid accumulation are self-limiting. At present, little is known about mechanisms to compensate excessive fluid transport. Here we describe an adaptive mechanism to dampen fluid loss during hypoxia. Initial studies confirmed previous observations of attenuated electrogenic Cl- secretion after epithelial hypoxia. A screen of known ion transporters in Cl- -secreting epithelia revealed selective downregulation of Na-K-2Cl cotransporter NKCC1 mRNA, protein, and function. Subsequent studies identified transcriptional repression of NKCC1 mediated by hypoxia-inducible factor (HIF). Chromatin immunoprecipitation analysis identified a functional HIF binding site oriented on the antisense strand of genomic DNA downstream of the transcription start site corresponding to the NKCC1 5'-untranslated region. Additional in vivo studies using conditional Hif1a-null mice revealed that the loss of HIF-1alpha in Cl- -secreting epithelia results in a loss of NKCC1 repression. These studies describe a novel regulatory pathway for NKCC1 transcriptional repression by hypoxia. These results suggest that HIF-dependent repression of epithelial NKCC1 may provide a compensatory mechanism to prevent excessive fluid loss during hypoxia.
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