Репозиторий Университета

© 2020, Springer Healthcare Ltd., part of Springer Nature. Introduction: The relationship between blood pressure (BP) and cerebral blood flow (CBF) is not fully understood. This study evaluated the impact of a perindopril arginine/indapamide (Pa/I) single-pill combination (SPC) on CBF in middle-aged patients. Methods: A total of 22 treatment-naïve patients with essential hypertension and at least one hypertension-mediated organ damage and 41 healthy controls were enrolled. At baseline, all participants underwent brain magnetic resonance imaging (MRI); patients with hypertension underwent an additional MRI at end of follow-up. Arterial spin labeling (ASL) was used to calculate CBF in the frontal lobe cortical plate. Patients with hypertension received once-daily Pa/I 5 mg/1.25 mg SPC, which could be increased to Pa/I 10 mg/2.5 mg at 2 weeks if necessary. Patients with hypertension underwent 24-h ambulatory BP monitoring (ABPM) at baseline and end of follow-up. Results: Mean baseline BP values were 146.2/93.1 and 119.1/76.1 mmHg in the hypertension and control groups, respectively. Patients with hypertension had significantly (p < 0.001) lower CBF in the cortical plate of both left (36.2 ± 8.3 vs. 45.3 ± 3.5 ml/100 g/min) and right (37.9 ± 7.9 vs. 45.8 ± 3.2 ml/100 g/min) frontal lobes compared to normotensive controls. At the end of follow-up, there was a statistically significant (p < 0.001) increase in CBF in the cortical plate of both left (from 36.2 ± 8.3 to 47.5 ± 9.8 ml/100 g/min) and right frontal lobes (from 37.9 ± 7.9 to 47.4 ± 10.1 ml/100 g/min) compared to baseline. No significant difference was found between end of follow-up CBF levels in frontal lobes of patients with hypertension and those of healthy controls at baseline. Office BP decreased by 24.2/15.5 mmHg and 24-h ABPM from 145.5/95.3 to 120.8/79.3 mmHg. Conclusion: In middle-aged, treatment-naïve patients with hypertension, Pa/I SPC was associated with increased CBF in the cortical plate of the frontal lobes, which achieved levels of normotensive controls. The increase in CBF had no clear association with observed BP changes. Registration number: ISRCTN67799751.

The arterial pulse wave (PW) is a rich source of information on cardiovascular (CV) health. It is widely measured by both consumer and clinical devices. However, the physical determinants of the PW are not yet fully understood, and the development of PW analysis algorithms is limited by a lack of PW data sets containing reference CV measurements. Our aim was to create a database of PWs simulated by a computer to span a range of CV conditions, representative of a sample of healthy adults. The typical CV properties of 25-75 yr olds were identified through a literature review. These were used as inputs to a computational model to simulate PWs for subjects of each age decade. Pressure, flow velocity, luminal area, and photoplethysmographic PWs were simulated at common measurement sites, and PW indexes were extracted. The database, containing PWs from 4,374 virtual subjects, was verified by comparing the simulated PWs and derived indexes with corresponding in vivo data. Good agreement was observed, with well-reproduced age-related changes in hemodynamic parameters and PW morphology. The utility of the database was demonstrated through case studies providing novel hemodynamic insights, in silico assessment of PW algorithms, and pilot data to inform the design of clinical PW algorithm assessments. In conclusion, the publicly available PW database is a valuable resource for understanding CV determinants of PWs and for the development and preclinical assessment of PW analysis algorithms. It is particularly useful because the exact CV properties that generated each PW are known.NEW & NOTEWORTHY First, a comprehensive literature review of changes in cardiovascular properties with age was performed. Second, an approach for simulating pulse waves (PWs) at different ages was designed and verified against in vivo data. Third, a PW database was created, and its utility was illustrated through three case studies investigating the determinants of PW indexes. Fourth, the database and tools for creating the database, analyzing PWs, and replicating the case studies are freely available.

© 2018 Pharmascope Publications. All rights reserved. To study the function of the endothelium in conducting vascular pharmacological samples in normal and blocking the synthesis of nitric oxide by ultrasound examination of the velocity of central blood flow in the femoral artery in comparison with the changes in systemic hemodynamics and the linear velocity of microcirculatory flow using laser flowmetry. It was studied the parameters of the blood flow velocity (the maximum systolic and diastolic velocity, average systolic and diastolic velocity, Gosling index of pulsatility and resistance index by the Doppler ultrasound Minimax-Doppler-K), the parameters of central circulation ("Biopac-systems MP-150", AcqKnowledge 4.2, USA), and linear velocity of the microcirculatory flow of the musculus vastus medialis (Biopac MP-150, USA) in intact animals and rats with N-Ni-tro-L-arginine methyl ester (L-NAME) induced deficiency of nitric oxide. Quantitative evaluation of endothelial dysfunction in the conduct of pharmacological tests with endothelium-dependent (acetylcholine) and endothe-lium-independent (sodium nitroprusside) vasodilatation is most indicative in calculating the coefficient reflecting the ratio of vascular responses areas in intact rats with L-NAME induced deficiency of nitric oxide. Blood flow parameters (the maximum systolic velocity, the calculated difference between systolic and diastolic velocities) showed a high correlation, both with mean arterial pressure and a linear velocity of the microcirculatory flow. We conclude, that ultrasound Doppler were reflected in the systemic and local vascular response to the administration of vasodilators. It allows an assessment of endothelial function by using the Minimax-Doppler-K device.

© 2018, Pleiades Publishing, Inc. The article presents empirical data on the possible use of transcranial Doppler sonography as a method for the identification of functional specialization of hemispheres. We investigated intrahemispheric differences in the increase in blood flow velocity indicators during the performance of cognitive tasks with verbal and nonverbal stimuli in 20 healthy right-handed participants and 20 right-handed patients with local unilateral vascular brain lesions. We observed interhemispheric and intrahemispheric differences in blood flow velocity indicators between arteries during the performance of cognitive tasks with different variants of verbal stimuli in all participants. It has been found that one of the hemispheres plays a dominant role in verbal and nonverbal stimulus processing.

© 2018 Media Sphera Publishing Group.All right reserved. Objective. This study aimed to assess the cognitive functions and cerebral blood flow measured with arterial spin labeling (ASL) and their possible correlations with vascular age in untreated middle-aged patients with grade 1-2 essential arterial hypertension (EAH). Methods. We examined 73 subjects aged 40-59 years (33 with EAH and 40 healthy volunteers [controls]). Neuropsychological assessment included Montreal Cognitive Assessment (MoCA), Trail Making test (part A and part B), Stroop Color and Word Test, verbal fluency test (phonemic verbal fluency and semantic verbal fluency), 10-item word list learning task. All subjects underwent brain MRI. MRI protocol included ASL. Vascular age was calculated by two techniques-using Framingham Heart Study risk tables and SCORE project scales. Results. Patients with EAH had lower performance on phonemic verbal fluency test and lower mean MoCA score (29.2±1.4 vs. 28.1±1.7 points) compared to controls (13.4±3.2, p=0.002; 29.2±1.4, p=0.001, respectively). White matter hyperintensities (WMH) were present in 7.5 % controls and in 51.5 % EAH patients (p=0.0002). Cerebral blood flow (CBF) in EAH patients was lower in both right (39.1±5.6 vs. 45.8±3.2 ml/100 g/min) and left frontal lobes of the brain (39.2±6.2 45.2±3.6 ml/100 g/min, respectively) compared to controls (p<0.001). EAH patients without WMH had lower CBF compared to controls (right frontal lobe: 39.5±5.1 ml/100 g/min, p=0.0002; left frontal lobe: 38.9±4.3 ml/100 g/min, p=0.00002). In EAH patients vascular age (57.7±7.4 and 64.6±11.0 years as measured by SCORE project scales and Framingham Heart Study risk tables, respectively) was significantly (p<0.001) greater than chronological one (50.2±6.2 years) and was significantly (p<0.001) higher than the corresponding values in the control group. Correlation analysis revealed negative significant associations between vascular age and MoCA score, phonemic verbal fluency test score and CBF. Conclusions. Treatment-naive middle-aged patients with uncomplicated grade 1-2 EAH compared to normotensive controls have lower mean scores in phonemic fluency test and MoCA, lower CBF, even in the absence of WMH, which correlates with vascular age, particularly with the value calculated by Framingham Heart Study risk tables. Early vascular ageing is important factor of brain impairment in hypertension in middle-aged patients even at early stages of EAH.

© 2018, Dynasty Publishing House. All rights reserved. The objective. Was to develop echographic and Doppler prognostic markers of lesions of the central nervous system (CNS) in premature newborns. Patients and methods. In accordance with the objective of the study we conducted a complex prospective examination of 196 pregnant women diagnosed with threatened preterm labour. The treatment group consisted of 166 women, whose pregnancy ended with spontaneous births at terms 22–36 wks, and premature newborns later developed various disorders of CNS. Results. We found morphological ultrasound and Doppler ultrasound specificities of fetal CNS against the background of threatened preterm labour depending on the term of gestation at the moment of birth and subsequent neurological disorders in premature infants. The most significant were changes of the ventriculo-cranial index, width of anterior horns of lateral ventricles, thalamo-occipital distance, systolic-diastolic ratio between vertebrobasilar vessels of the brain. Conclusion. Such a detailed prenatal diagnosis contributes to noninvasive prognostication of the severity of neurological lesions of CNS in premature infants. The results showed interrelations between perinatal outcomes and initial blood flow impairment of fetal CNS in 97% of observations.

It reports the results of primary basal blood flow in partially edentulous bone tissue with atrophy, as well as comparative evaluation of haemomicrocirculation level of the alveolar bone mucosa after bone augmentation via tunneling and conventional methods. The results of the initial state of microcirculation in the mucous membrane of the alveolar process in the partially edentulous area show a 45% decrease of blood flow (M), its intensity (s) by 60%. Microcirculatory shifts in blood flow levels indicators, its intensity, vasomotor activity are more evident when using the conventional method, where revascularization takes more than five months. When using the tunnel method, there is an improvement in haemodynamic mechanisms of tissue blood flow regulation. Microcirculation is restored 4 months after surgery.

© 2018 Sergey S. Simakov. The study of the physiological and pathophysiological processes in the cardiovascular system is one of the important contemporary issues, which is addressed in many works. In this work, several approaches to the mathematical modelling of the blood flow are considered. They are based on the spatial order reduction and/or use a steady-state approach. Attention is paid to the discussion of the assumptions and suggestions, which are limiting the scope of such models. Some typical mathematical formulations are considered together with the brief review of their numerical implementation. In the first part, we discuss the models, which are based on the full spatial order reduction and/or use a steady-state approach. One of the most popular approaches exploits the analogy between the flow of the viscous fluid in the elastic tubes and the current in the electrical circuit. Such models can be used as an individual tool. They also used for the formulation of the boundary conditions in the models using one dimensional (1D) and three dimensional (3D) spatial coordinates. The use of the dynamical compartment models allows describing haemodynamics over an extended period (by order of tens of cardiac cycles and more). Then, the steady-state models are considered. They may use either total spatial reduction or two dimensional (2D) spatial coordinates. This approach is used for simulation the blood flow in the region of microcirculation. In the second part, we discuss the models, which are based on the spatial order reduction to the 1D coordinate. The models of this type require relatively small computational power relative to the 3D models. Within the scope of this approach, it is also possible to include all large vessels of the organism. The 1D models allow simulation of the haemodynamic parameters in every vessel, which is included in the model network. The structure and the parameters of such a network can be set according to the literature data. It also exists methods of medical data segmentation. The 1D models may be derived from the 3D Navier - Stokes equations either by asymptotic analysis or by integrating them over a volume. The major assumptions are symmetric flow and constant shape of the velocity profile over a cross-section. These assumptions are somewhat restrictive and arguable. Some of the current works paying attention to the 1D model's validation, to the comparing different 1D models and the comparing 1D models with clinical data. The obtained results reveal acceptable accuracy. It allows concluding, that the 1D approach can be used in medical applications. 1D models allow describing several dynamical processes, such as pulse wave propagation, Korotkov's tones. Some physiological conditions may be included in the 1D models: gravity force, muscles contraction force, regulation and autoregulation.

© 2018, Media Sphera Publishing Group. All rights reserved. Objective. To study cognitive functions, anxiety and depression levels, 24-hour blood pressure (BP) profile, cerebral blood flow (CBF) perfusion in treatment-naive middle-aged patients with uncomplicated essential arterial hypertension (EAH) depending on the white matter hyperintensities (WMH) burden. Material and methods. Forty-one hypertensive patients (mean age 46.2±4.6 years) and 41 healthy volunteers (mean age 50.3±6.7 years) were enrolled to the study. All subjects underwent brain MRI (MAGNETOM Skyra 3.0T, T1, T2 FSE, T2 FLAIR, T1 MPRAGE, ASL), Montreal cognitive assessment (MoCA), 10-word learning task, verbal fluency test, trail making test, Stroop color and word test, anxiety and depression assessment with Hamilton rating scales, 24-hour blood pressure monitoring (ABPM). Results. WMH were found in 22 (53.7%) hypertensive patients and in 3 (7.3%) healthy volunteers (p=0.0002). Hypertensive patients had the significantly lower CBF compared to controls (p<0.001). Conclusion. WMH were identified in treatment-naive middle-aged patients with uncomplicated mild to moderate EAH. There was an association between WMH and lower CBF in the cortical plate of frontal lobes, SBP variability and worse cognition. Cerebral hypoperfusion can cause cognitive impairment even in the earliest stages of EAH, which increases due to emotional disorders.

© 2018 Ima-Press Publishing House. All rights reserved. Arterial spin labeling (ASL) is a promising non-invasive method to assess cerebral perfusion, which identifies a decrease in cerebral blood flow (CBF). Objective: to assess cerebral perfusion in middle-aged untreated patients with uncomplicated grade 1-2 hypertension compared to same-age healthy controls. Patients and methods. 33 patients with essential hypertension and 40 healthy individuals (a control group) at the age of 40-59 years were examined. 24-hour blood pressure (BP) monitoring and brain magnetic resonance imaging were performed in different modes (T1 MPRAGE, T2 TSE, T2 FLAIR, DTI, and ASL). Results. White matter hyperintensive changes were found in 7.5% of the healthy individuals and in 51.5% of the hypertensive patients (p = 0.0002). In hypertensive patients, CBF in the cortical plate of anterior frontal regions was significantly (p ( 0.001) lower than that in the controls: right CBF, 39.1±5.6 and 45.8±3.2 ml/100 g/min, respectively; left CBF, 39.2±6.2 and 45.2±3.6 ml/100 g/min, respectively. In hypertensive patients with white matter hyperintensive changes, CBF was significantly lower than that in the controls: right CBF, 38.5±5.9 ml/100 g/min (p = 0.0001); left CBF, 39.2±6.7 ml/100 g/min (p = 0.002), and in those without these changes, right CBF was 39.5±5.1 ml/100 g/min (p = 0.0002); left CBF was 38.9±4.3 ml/100 g/min (p = 0.00002). Correlation analysis revealed significant inverse correlations of CBF with BP and systolic BP variability. Conclusion. Lower cerebral perfusion occurs in middle-aged untreated patients with uncomplicated grade 1-2 hypertension even in the absence of white matter hyperintensity foci.