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Your search keyword '"Varsos, Vassilis"' showing total 12 results
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12 results on '"Varsos, Vassilis"'

4. A noninvasive estimation of cerebral perfusion pressure using critical closing pressure

Author

Varsos, Georgios V, Kolias, Angelos G, Smielewski, Peter, Brady, Ken M, Varsos, Vassilis G, Hutchinson, Peter J, Pickard, John D, Czosnyka, Marek, Kolias, Angelos [0000-0003-3992-0587], Smielewski, Peter [0000-0001-5096-3938], Hutchinson, Peter [0000-0002-2796-1835], Pickard, John [0000-0002-5762-6667], Czosnyka, Marek [0000-0003-2446-8006], and Apollo - University of Cambridge Repository

Subjects
MCA = middle cerebral artery, Adult, Male, FV = flow velocity, noninvasive model, AUC = area under the curve, Adolescent, Intracranial Pressure, Ultrasonography, Doppler, Transcranial, Blood Pressure, nICP = noninvasive estimator of ICP, vascular disorders, Sensitivity and Specificity, Young Adult, Craniocerebral Trauma, Humans, eCPP = noninvasive estimator of CPP, GOS = Glasgow Outcome Scale, CrCP = critical closing pressure, Monitoring, Physiologic, Retrospective Studies, cerebral perfusion pressure, CBF = cerebral blood flow, ICP = intracranial pressure, TAU = time constant of the cerebrovascular arterial bed, CVR = cerebrovascular resistance, TCD = transcranial Doppler, GCS = Glasgow Coma Scale, Middle Aged, critical closing pressure, ROC = receiver operating characteristic, ABP = arterial blood pressure, CPP = cerebral perfusion pressure, Cerebrovascular Circulation, transcranial Doppler ultrasonography, Female, TBI = traumatic brain injury, Blood Flow Velocity, IQR = interquartile range
Abstract

OBJECT: Cerebral blood flow is associated with cerebral perfusion pressure (CPP), which is clinically monitored through arterial blood pressure (ABP) and invasive measurements of intracranial pressure (ICP). Based on critical closing pressure (CrCP), the authors introduce a novel method for a noninvasive estimator of CPP (eCPP). METHODS: Data from 280 head-injured patients with ABP, ICP, and transcranial Doppler ultrasonography measurements were retrospectively examined. CrCP was calculated with a noninvasive version of the cerebrovascular impedance method. The eCPP was refined with a predictive regression model of CrCP-based estimation of ICP from known ICP using data from 232 patients, and validated with data from the remaining 48 patients. RESULTS: Cohort analysis showed eCPP to be correlated with measured CPP (R = 0.851, p < 0.001), with a mean ± SD difference of 4.02 ± 6.01 mm Hg, and 83.3% of the cases with an estimation error below 10 mm Hg. eCPP accurately predicted low CPP (< 70 mm Hg) with an area under the curve of 0.913 (95% CI 0.883-0.944). When each recording session of a patient was assessed individually, eCPP could predict CPP with a 95% CI of the SD for estimating CPP between multiple recording sessions of 1.89-5.01 mm Hg. CONCLUSIONS: Overall, CrCP-based eCPP was strongly correlated with invasive CPP, with sensitivity and specificity for detection of low CPP that show promise for clinical use.

Published
2015

6. Cerebral Vasospasm Affects Arterial Critical Closing Pressure

Author

Varsos, Georgios V, primary, Budohoski, Karol P, additional, Czosnyka, Marek, additional, Kolias, Angelos G, additional, Nasr, Nathalie, additional, Donnelly, Joseph, additional, Liu, Xiuyun, additional, Kim, Dong-Joo, additional, Hutchinson, Peter J, additional, Kirkpatrick, Peter J, additional, Varsos, Vassilis G, additional, and Smielewski, Peter, additional

Published
2014
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7. Complex interactions between the components of the PI3K/AKT/mTOR pathway, and with components of MAPK, JAK/STAT and Notch-1 pathways, indicate their involvement in meningioma development

Author

El-Habr, Elias A., primary, Levidou, Georgia, additional, Trigka, Eleni-Andriana, additional, Sakalidou, Joanna, additional, Piperi, Christina, additional, Chatziandreou, Ilenia, additional, Spyropoulou, Anastasia, additional, Soldatos, Rigas, additional, Tomara, Georgia, additional, Petraki, Kalliopi, additional, Samaras, Vassilis, additional, Zisakis, Athanasios, additional, Varsos, Vassilis, additional, Vrettakos, George, additional, Boviatsis, Efstathios, additional, Patsouris, Efstratios, additional, Saetta, Angelica A., additional, and Korkolopoulou, Penelope, additional

Published
2014
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8. Comparative immunohistochemical analysis of aurora-A and aurora-B expression in human glioblastomas. Associations with proliferative activity and clinicopathological features

Author

Samaras, Vassilis, primary, Stamatelli, Angeliki, additional, Samaras, Efstathios, additional, Arnaoutoglou, Christos, additional, Arnaoutoglou, Marianthi, additional, Stergiou, Ioanna, additional, Konstantopoulou, Paraskevi, additional, Varsos, Vassilis, additional, Karameris, Andreas, additional, and Barbatis, Calypso, additional

Published
2009
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12. Comparative immunohistochemical analysis of aurora-A and aurora-B expression in human glioblastomas. Associations with proliferative activity and clinicopathological features.

Author

Samaras V, Stamatelli A, Samaras E, Arnaoutoglou C, Arnaoutoglou M, Stergiou I, Konstantopoulou P, Varsos V, Karameris A, and Barbatis C

Subjects
Adult, Aged, Aged, 80 and over, Analysis of Variance, Brain Neoplasms mortality, Brain Neoplasms therapy, Combined Modality Therapy, Female, Glioblastoma mortality, Glioblastoma therapy, Humans, Immunohistochemistry, Kaplan-Meier Estimate, Ki-67 Antigen metabolism, Male, Middle Aged, Statistics, Nonparametric, Treatment Outcome, Brain Neoplasms metabolism, Cell Proliferation, Cerebral Cortex metabolism, Glioblastoma metabolism, Protein Serine-Threonine Kinases metabolism
Abstract

In the present study, we carried out a comparative immunohistochemical analysis of aurora-A and aurora-B expression in 40 patients with primary glioblastomas, and attempted to identify any associations with Ki-67 index and the patients' clinical features. The impact of various treatment modalities and proliferative activity on patient outcome was also assessed. Immunohistochemistry was carried out using formalin-fixed and paraffin-embedded tissue sections. Aurora-A expression was higher in tumors with high Ki-67 expression (p=0.01) and was positively, though marginally, related to aurora-B expression (p=0.085). Aurora-B expression was not linked to Ki-67 expression (p=0.182). Lower aurora-A immunohistochemical expression, chemotherapy administration, and tumor localization in one lobe of the brain implied a greater probability of patient survival in univariate analysis (p=0.044, p=0.008, p=0.041, respectively). Ki-67 and aurora-B immunoreactivities were not associated with patient survival (p=0.918 and p=0.539, respectively). To our knowledge, for the first time, the association between aurora-A and aurora-B expression, the correlation of aurora-A with Ki-67 index, and the prognostic impact of aurora-A expression were assessed in glioblastomas. Although we addressed a prognostic connotation of aurora-A, we presume that aurora-A and aurora-B play a complicated role within glioblastomas. Further examinations of larger series are required, so that definite conclusions can be drawn.

Published
2009
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