Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

4 ( 1 )

2019 ( 52 )

2018 ( 94 )

2017 ( 89 )

Custom range...

Search Results: 1 - 10 of 41034 matches for " Elena Z. Golukhova "
All listed articles are free for downloading (OA Articles)
Page 1 /41034
Display every page Item
Size of Left Cardiac Chambers Correlates with Cerebral Microembolic Load in Open Heart Operations
Elena Z. Golukhova,Anna G. Polunina,Svetlana V. Zhuravleva,Natalia P. Lefterova,Alexey V. Begachev
Cardiology Research and Practice , 2010, DOI: 10.4061/2010/143679
Abstract: Background. Microemboli are a widely recognized etiological factor of cerebral complications in cardiac surgery patients. The present study was aimed to determine if size of left cardiac chambers relates to cerebral microembolic load in open heart operations. Methods. Thirty patients participated in the study. Echocardiography was performed in 2-3 days before surgery. A transcranial Doppler system was used for registering intraoperative microemboli. Results. Preoperative left atrium and left ventricular end-systolic and end-diastolic sizes significantly correlated with intraoperative microembolic load ( , 0.57 and 0.53, , resp.). The associations between left ventricular diameters and number of cerebral microemboli remained significant when cardiopulmonary bypass time was included as a covariate into the analysis. Conclusions. The present results demonstrate that increased size of left heart chambers is an influential risk factor for elevated cerebral microembolic load during open heart operations. Mini-invasive surgery and carbon dioxide insufflation into wound cavity may be considered as neuroprotective approaches in patients with high risk of cerebral microembolism. 1. Introduction Microemboli are a widely recognized etiological factor of cerebral complications in cardiac surgery patients. Our group found significant associations between microembolic load and deliria and cognitive dysfunction after on-pump operations [1, 2]. Microemboli are observed during on-pump operations in nearly all patients [1, 3]. However, the number of microemboli considerably varies in different cases being the largest in open heart operations. In the study of Abu-Omar et al. [4], open heart procedures were associated with a 22-fold increase in microemboli in comparison to off-pump coronary patients. Prevalence of postoperative delirium and cognitive dysfunction was reported to be considerably higher after valve operations in comparison with coronary surgery as well [1, 5]. Progress in on-pump technologies resulted in reduced cerebral microembolic load and, therefore, neurological complications during contemporary cardiac operations. Membrane oxygenators instead of bubble ones and arterial line filters are used at present in the majority of cardiac surgery centers. Off-pump surgery, epiaortic scanning, minimized aortic manipulations, and perfusionist interventions were introduced as emboli lowing approaches. Hence, correct knowledge about potential sources of microemboli increases quality of surgery and, therefore, improves outcomes. However, it is still unclear why the
Electroencephalography as a Tool for Assessment of Brain Ischemic Alterations after Open Heart Operations
Elena Z. Golukhova,Anna G. Polunina,Natalia P. Lefterova,Alexey V. Begachev
Stroke Research and Treatment , 2011, DOI: 10.4061/2011/980873
Abstract: Cardiac surgery is commonly associated with brain ischemia. Few studies addressed brain electric activity changes after on-pump operations. Eyes closed EEG was performed in 22 patients (mean age: ) before and two weeks after valve replacement. Spouses of patients were invited to participate as controls. Generalized increase of beta power most prominent in beta-1 band was an unambiguous pathological sign of postoperative cortex dysfunction, probably, manifesting due to gamma-activity slowing (“beta buzz” symptom). Generalized postoperative increase of delta-1 mean frequency along with increase of slow-wave activity in right posterior region may be hypothesized to be a consequence of intraoperative ischemia as well. At the same time, significant changes of alpha activity were observed in both patient and control groups, and, therefore, may be considered as physiological. Unexpectedly, controls showed prominent increase of electric activity in left temporal region whereas patients were deficient in left hemisphere activity in comparison with controls at postoperative followup. Further research is needed in order to determine the true neurological meaning of the EEG findings after on-pump operations. 1. Introduction Cardiac surgery is commonly associated with perioperative brain ischemia. Neuroimaging studies consistently demonstrated acute brain edema and global decrease of brain metabolism during first three days after on-pump surgery [1–4]. In addition, 20–45% of on-pump patients demonstrated multiple small ischemic lesions postoperatively [4–8]. Only 20% of patients with neuroimaging ischemic lesions showed clinical signs of stroke or acute encephalopathy. Nevertheless, the majority of on-pump patients reported memory decrease several months or even several years after surgery [9, 10]. Neuropsychological studies consistently confirmed mild cognitive decline in the majority of cardiac surgery patients at discharge and in 7–69% of patients at 1–3 months followup after surgery [11]. Hence, mild brain ischemic injury is common after on-pump surgery appearing as postoperative cognitive dysfunction. Overall, total volume of brain ischemic alterations correlated with clinical symptoms in the majority of neuroimaging studies [7, 8, 12, 13]. Many researchers pointed to the embolic genesis of the postoperative brain infarcts due to characteristic distribution of the latter ones [12, 14]. Significant associations between microembolic load and severity of postoperative brain injury were consistently shown [2, 15, 16]. In our relatively young patient cohort we found
Cognitive Dysfunction after On-Pump Operations: Neuropsychological Characteristics and Optimal Core Battery of Tests
Anna G. Polunina,Elena Z. Golukhova,Alla B. Guekht,Natalia P. Lefterova,Leo A. Bokeria
Stroke Research and Treatment , 2014, DOI: 10.1155/2014/302824
Abstract: Postoperative cognitive dysfunction (POCD) is a mild form of perioperative ischemic brain injury, which emerges as memory decline, decreased attention, and decreased concentration during several months, or even years, after surgery. Here we present results of our three neuropsychological studies, which overall included 145 patients after on-pump operations. We found that the auditory memory span test (digit span) was more effective as a tool for registration of POCD, in comparison with the word-list learning and story-learning tests. Nonverbal memory or visuoconstruction tests were sensitive to POCD in patients after intraoperative opening of cardiac chambers with increased cerebral air embolism. Psychomotor speed tests (digit symbol, or TMT A) registered POCD, which was characteristic for elderly atherosclerotic patients. Finally, we observed that there were significant effects of the order of position of a test on the performance on this test. For example, the postoperative performance on the core tests (digit span and digit symbol) showed minimal impairment when either of these tests was administered at the beginning of testing. Overall, our data shows that the selection of tests, and the order of which these tests are administered, may considerably influence the results of studies of POCD. 1. Introduction Postoperative cognitive dysfunction (POCD) is a mild form of perioperative ischemic brain injury, which emerges predominantly as memory decline during several months, or even years after surgery [1–5]. In addition, patients commonly report decreased concentration, attention span, and psychomotor speed. Both patients and spouses of patients notice postoperative memory decline after the first year after operation [3]. Negative effects on driving abilities during several months after uncomplicated cardiac surgeries were registered [6]. Some researchers include a broader spectrum of disorders around the term “postoperative cognitive dysfunction”—these disorders may include perioperative ischemic brain damage, brain death, delirium, stroke, and transitory ischemic attack [5]. Multiple neuropsychological studies confirm a decline in the performance of cognitive tests in the majority of patients during the first week after cardiac surgery and in about 30–40% of patients in 1–3 months after surgery in comparison with preoperative testing [review: [7]]. In young patients, cognitive function tends to be restored to its preoperative levels, in about 6–12 months after surgery [8–12], and there is no association between POCD and risk of dementia, in this young
De la planificación familiar a la salud reproductiva: retos y obstáculos
Elena Zú?iga Herrera
Papeles de población , 1994,
Regularity of the solutions to SPDEs in metric measure spaces
Elena Issoglio,Martina Z?hle
Mathematics , 2014, DOI: 10.1007/s40072-015-0048-8
Abstract: In this paper we study the regularity of non-linear parabolic PDEs and stochastic PDEs on metric measure spaces admitting heat kernels. In particular we consider mild function solutions to abstract Cauchy problems and show that the unique solution is H\"older continuous in time with values in a suitable fractional Sobolev space. As this analysis is done via a-priori estimates, we can apply this result to stochastic PDEs on metric measure spaces and solve the equation in a pathwise sense for almost all paths. The main example of noise term is of fractional Brownian type and the metric measure spaces can be classical as well as given by various fractal structures. The whole approach is low dimensional and works for spectral dimensions less than 4.
Ontological Model-Based Transparent Access To Information In A Medical Multi-Agent System
Felicia G?Z?-BELCIUG,Cristina Elena TURCU
Journal of Applied Computer Science & Mathematics , 2012,
Abstract: Getting the full electronic medical record of a patient is an important step in providing a quality medical service. But the degree of heterogeneity of data from health unit informational systems is very high, because each unit can have a different model for storing patients’ medical data. In order to achieve the interoperability and integration of data from various medical units that store partial patient medical information, this paper proposes a multi-agent systems and ontology based approach. Therefore, we present an ontological model for describing the particular structure of the data integration process. The system is to be used for centralizing the information from a patient’s partial medical records. The main advantage of the proposed model is the low ratio between the complexity of the model and the amount of information that can be retrieved in order to generate the complete medical history of a patient.
Teoría G: un futuro paradigma para el análisis de pruebas psicométricas
María Elena Zú?iga-Brenes
Actualidades en Psicología , 2007,
Abstract: La teoría de la generalizabilidad (teoría G) permite medir la confiabilidad de una prueba por medio de la cuantificación de la importancia de cada una de sus fuentes de variabilidad. Se redefine el error, como condición o faceta de medición, utilizando el coeficiente de generalizabilidad como medida para estimar la confiabilidad. Este enfoque no contradice los planteamientos fundamentales de la teoría clásica de los tests, sino que puede ser visto como una extensión de ella. Se concluye que, si bien en muchos casos los instrumentos psicométricos se usan para tomar decisiones relativas (modelo con referencia a normas), siendo en esa situación suficiente la teoría clásica de los tests, otras instancias como las que involucran el uso de pruebas educativas, suelen requerir decisiones basadas en estándares absolutos de desempe o, donde la teoría G constituye una herramienta de gran utilidad y mucho más informativa que el enfoque clásico.
Evidence that ampicillin and streptomycin can suppress autotomic behavior in rats
Krsljak Elena S.,Staj?i? Z.
Acta Veterinaria , 2004, DOI: 10.2298/avb0403145k
Abstract: Autotomy is a phenomenon of deafferentation of the rat limb by transection of the sciatic and saphenous nerves, inducing an automutilation of the limb as a response to painful stimuli generated from the amputation neuroma. Autotomy has been proposed as an experimental model for neuralgia pain. The present study was designed to investigate the influence of streptomycin, ampicillin and chloramphenicol applied either in the vicinity of the nerve stump or intramuscularly. The course of autotomy was followed during 8 weeks using the scoring system of Wall et al. (1979). It was shown that streptomycin and ampicillin can suppress autotomy when applied topically whereas systemic use of the investigated antibiotics was efficient only when streptomycin was injected.
Campos o subcampos?
María Elena Hernández Ramiréz
Comunicación y sociedad , 2006,
Elementary pathwise methods for nonlinear parabolic and transport type SPDE with fractal noise
Michael Hinz,Elena Issoglio,Martina Z?hle
Mathematics , 2013,
Abstract: We survey some of our recent results on existence, uniqueness and regularity of function solutions to parabolic and transport type partial differential equations driven by non-differentiable noises. When applied pathwise to random situations, they provide corresponding statements for stochastic partial differential equations driven by fractional noises of sufficiently high regularity order. The approach is based on semigroup theory.
Page 1 /41034
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.