Long-Term Sheep Implantation of WIMAGINE®, a Wireless 64-Channel Electrocorticogram Recorder.

This article deals with the long-term preclinical validation of WIMAGINE® (Wireless Implantable Multi-channel Acquisition system for Generic Interface with Neurons), a 64-channel wireless implantable recorder that measures the electrical activity at the cortical surface (electrocorticography, ECoG). The WIMAGINE® implant was designed for chronic wireless neuronal signal acquisition, to be used e.g., as an intracranial Brain-Computer Interface (BCI) for severely motor-impaired patients. Due to the size and shape of WIMAGINE®, sheep appeared to be the best animal model on which to carry out long-term in vivo validation. The devices were implanted in two sheep for a follow-up period of 10 months, including idle state cortical recordings and Somato-Sensory Evoked Potential (SSEP) sessions. ECoG and SSEP demonstrated relatively stable behavior during the 10-month observation period. Information recorded from the SensoriMotor Cortex (SMC) showed an SSEP phase reversal, indicating the cortical site of the sensorimotor activity was retained after 10 months of contact. Based on weekly recordings of raw ECoG signals, the effective bandwidth was in the range of 230 Hz for both animals and remarkably stable over time, meaning preservation of the high frequency bands valuable for decoding of the brain activity using BCIs. The power spectral density (in dB/Hz), on a log scale, was of the order of 2.2, -4.5 and -18 for the frequency bands (10-40), (40-100), and (100-200) Hz, respectively. The outcome of this preclinical work is the first long-term in vivo validation of the WIMAGINE® implant, highlighting its ability to record the brain electrical activity through the dura mater and to send wireless digitized data to the external base station. Apart from local adhesion of the dura to the skull, the neurosurgeon did not face any difficulty in the implantation of the WIMAGINE® device and post-mortem analysis of the brain revealed no side effect related to the implantation. We also report on the reliability of the system; including the implantable device, the antennas module and the external base station.

Pulse wave velocity and other indicators of arterial stiffness in hypertension comorbidity and chronic obstructive pulmonary disease.

AIM: The aim is to study pulse wave velocity (PWV) and other parameters of arterial stiffness in patients with comorbid arterial hypertension (AH) and chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: 32 patients with a combination of AH and COPD (group 1), 30 patients with isolated hypertension (group 2), 18 patients with isolated COPD (group 3), 30 healthy subjects (control group) were examined. Applanation tonometry and pulse wave contour analysis at the carotid-femoral segment were made by SphygmoCor (AtCor Medical). RESULTS: Aortic systolic blood pressure in patients with the combination of hypertension and COPD was higher compared to the group of the patients with isolated hypertension by 9.83% (p=0.02), and the patients with COPD by 41.5% (p = 0.000042), respectively. Central pulse pressure in the first group was higher compared to the second group by 29.58% (p=0.00022), in the third group - by 53.4% (p=0.0029). The combination of hypertension and COPD (ß=0.42, p=0.00019), age (ß=0.39, p=0.0002) and the level of aortic pulse pressure (ß=0.54, p=0.001) were marked as independent factors of PWV increasing according to the multiple regression analysis. CONCLUSION: In patients with a combination of hypertension and COPD the increase in PWV, systolic and pulse pressure in the ascending aorta was observed, compared to patients with isolated hypertension, isolated COPD and the control group during applanation tonometry.

[ARTERIAL STIFFNESS AND BONE MINERAL DENSITY IN WOMEN WITH CORONARY HEART DISEASE AND CONCOMITANT SEVERE OSTEOPOROSIS].

The aim of the study was to estimate arterial stiffness and bone mineral density (BMD) in women with coronary heart disease (CHD) and concomitant osteoporosis. It included 120 patients (mean age 68.5 ± 8.7 years) divided into 2 groups matched for age and CHD duration. Group I was comprised of 74 women with CHD and severe osteoporosis, group 2 consisted of 46 women with isolated CHD. Carotid-femoral pulse wave velocity and central pulse wave were subjected to contour analysis by applanation tonometry using a SphygmoCor AtCor Medical apparatus (Australia). BMD was measured in lumbar vertebrae and proximal part of the femur by X-ray densitometer (XRD). Statistical treatment of the data obtained was performed with the use of Statistica 6.0 package, Wald-Wolfovitz criterion, and multifactorial regressive analysis; differences were considered statistically significant when the calculated P value was less than 0.05. Women with CHD and osteoporosis had higher arterial (diastolic/systolic) pressure, mean aortic pressure, and pulse wave velocity than patients with isolated CHD. The independent determinants of carotid-femoral segment stffness were age (ß = 0.3, 95% CI 0.08-0.11, p = 0.027), BMD in the proximal part of the femur based on Z criterion (ß = 5.02, 95% CI 8.4-10.6, p = 0.0059), BMD in the Wards area based on T criterion ß = 5.07, 95% CI 6.0-8.1, p = 0.005). It is concluded that women with CHD and osteoporosis have elevated parameters of arterial stiffness including carotid-femoral pulse wave velocity, augmentation index, central pulse pressure, BMD in lumbar vertebrae and proximal part of the femur. Age and BMD in the proximal part of the femur are independent factors affecting arterial stiffness.

[Experimental hybridization of voies of the genus Microtus s.l. M. socialis with species of the group arvalis (Mammalia, Rodentia)].

The results of interspecific crosses of the social vole Microtus socialis with the Altai vole M. obscurus, the East European vole M. rossiaemeridionalis, and the Transcaspian vole M. transcaspicus are presented. The role of the sperm head structure in the reproductive isolation of this species was studied. Hybrids were obtained in five of the six crossing combinations. It is established that significant differences in the sperm head shape in the social vole and in arvalis group species do not prevent fertilization. The sterility of hybrids indicates the existence of postcopulative mechanisms of reproductive isolation.

[The immunologic disorders and dysfunction of endothelium as predictors of development of hypertrophy of left ventricle of heart in patients with hypertension disease].

The sampling included 231 patient with hypertension disease of stage I-II. The hypertrophy of left ventricle of heart was established in 97 patients (group I) and 134 patients had no hypertrophy of left ventricle of heart (group II). The control group consisted of 25 healthy persons. The increase of tumor necrosis factor alpha and interleukin beta was established in group I as compared with group II and control group. In patients of group I the expressed dysfunction of endothelium was observed. The increase of endothelin I and number of desquamated endotheliocytes as compared with group II and healthy persons was established. The direct relationship between increase of concentration of analyzed cytokines and presence of hypertrophy of left ventricle of heart is revealed.

[24-hour monitoring central aortic pressure in patients with hypertensive disease and concomitant chronic obstructive pulmonary disease].

A total of 58 patients with essential hypertension were examined. 27 of them had a combination of essential hypertension and chronic obstructive pulmonary disease (COPD), 31 persons had isolated essential hypertension. The control group included 13 healthy individuals. The daily monitoring of blood pressure with a BPLab apparatus and the analysis of peripheral and central aortic pressure were performed. Comparison of groups was carried out using the Mann-Whitney test. The combination of hypertension and COPD was associated with increased daily and average daily peripheral and central aortic pressure compared with isolated essential hypertension and the control group. During daily monitoring of peripheral blood pressure the "dipper" type predominated in patients with isolated essential hypertension (41, 95%) and "non-dipper" type in those with comorbid disorders (44, 44%). The analysis of nocturnal blood pressure reduction in the aorta in patients with essential hypertension and COPD revealed the increased frequency of "non-dipper" type (55, 55%). The analysis of the central aortic pressure in patients with isolated essential hypertension showed the decreased incidence of "dipper" type (21, 87%). It is concluded that daily monitoring of the central aortic pressure permits to identify abnormal profiles with a higher frequency than the study of peripheral blood pressure.

[Lipid peroxidation in hypertensive disease concurrent with chronic obstructive pulmonary disease].

A hundred and thirty-four hypertensive patients were examined, 75 of them had concomitant first-degree chronic obstructive pulmonary disease (COPD). As compared with the control group, the patients were found to have elevated levels of primary, secondary, and intermediate products of serum lipid peroxidation and lower activities of catalase of red blood cells and their peroxide resistance. All changes were most pronounced in concomitant COPD.

[Production of certain cytokines in blood sera of patients with hypertensive disease and early stages of concomitant chronic obstructive pulmonary disease].

The results of investigation of blood serum interleikins in hypertensive patients in combination with early stages of chronic obstructive pulmonary disease (COPD) are presented. The increase of interleikin 1beta, tumor necrosis factor-alpha in hypertensive patients of the I - II stages in comparison with healthy person was marked. In the presence of accompanied COPD of the I stage more increased number of cytokins was determined. Changes of interleukin-4 patients of both groups were not found.

[Gastric cytomedines effects on immune response in acute immobilization stress in rats].

Effects of gastric cytomedines on repair and immune response were studied in 137 white non-inbred rats. Erosions of gastric mucosa were induced by acute immobilization stress. A decrease in antibody production, titers of hemagglutinins and hemolysins was found on day 2 after stress. Gastric cytomedines in a dose 0.15 mg/kg intramuscularly stimulate immune response (increased production of antibodies, antibody dependent cellular cytotoxicity index, titers of hemagglutinins and hemolysins), fast erosions epithelization and have a protective action.

[Ventramine and lipid peroxidation in children with erosive gastroduodenitis].

43 patients and 20 healthy children, aged 11-15, were examined. Increased contents of primary, secondary, intermediary and final products of lipid peroxidation (LPO) in serum lipids as well as an intensified antioxidant activity were registered in children with erosive gastroduodenitis. Ventramine, when used in the treatment of erosive gastroduodenitis in children, arrests rapidly the clinical signs of the disease and normalizes LPO.

Polynomial neural network for linear and non-linear model selection in quantitative-structure activity relationship studies on the internet.

This article presents a self-organising multilayered iterative algorithm that provides linear and non-linear polynomial regression models thus allowing the user to control the number and the power of the terms in the models. The accuracy of the algorithm is compared to the partial least squares (PLS) algorithm using fourteen data sets in quantitative-structure activity relationship studies. The calculated data show that the proposed method is able to select simple models characterized by a high prediction ability and thus provides a considerable interest in quantitative-structure activity relationship studies. The software is developed using client-server protocol (Java and C++ languages) and is available for world-wide users on the Web site of the authors.

Pharmaceutical fingerprinting in phase space. 1. Construction of phase fingerprints.

The present study proposes a general method for constructing pharmaceutical fingerprints in the analysis of HPLC trace organic impurity patterns. The approach considers signals in phase space and accounts for two different types of noise: additive and perturbative. The first type, additive noise, contributes to distortion of the absolute values of signal peaks. The second type, perturbative noise, contributes to variations of the retention times of signal peaks and distorts the time scale of the trace organic impurity patterns. The ability of the proposed approach to consider both types of noise significantly distinguishes it from existing methods of data analysis that are usually designed to treat only the additive noise. Analysis of the HPLC signals in phase space eliminates the problem of perturbation noise and enables detection and comparison of similar signal segments recorded at different retention times. The current study analyzes the chromatographic trace organic impurity patterns collected from six different manufacturers of L-tryptophan using three HPLC columns. For five manufacturers the variability of data recorded with the same column are in perfect agreement with the proposed model. A significant variance of parameters is detected for one manufacturer, thus indicating a possible change in its product consistency. The analysis in phase space is also used to explain the previously detected variability of HPLC signals across columns. The accompanying paper reports an application of the proposed approach for the pattern recognition of HPLC data.

Pharmaceutical fingerprinting in phase space. 2. Pattern recognition.

The current study introduces an approach for pattern recognition of drug manufacturers according to their HPLC trace impurity data. This method considers signals in phase space and accounts for two different types of noise: additive and perturbative. The pharmaceutical fingerprints are estimated as mean trajectories of HPLC trace impurity data and are used as reference models for recognition of new data by the minimal length classifier. The chromatographic trace organic impurity patterns collected from six different manufacturers of L-tryptophan are analyzed as an example. The prediction ability of the new method tested using three different cross-validation procedures remains about 95% even if the number of available data in the training sets decreases by 5 times. The accuracy of prediction in phase space is superior compared to results calculated using a Window Preprocessing method and artificial neural networks. The difference in performance between new and previous methods becomes more significant under particular conditions that are more adequate for practical application of the method. In addition, the current approach enables simple and comprehensive interpretation of the calculated results.

Application of a pruning algorithm to optimize artificial neural networks for pharmaceutical fingerprinting.

The present study investigates an application of artificial neural networks (ANNs) for use in pharmaceutical fingerprinting. Several pruning algorithms were applied to decrease the dimension of the input parameter data set. A localized fingerprint region was identified within the original input parameter space from which a subset of input parameters was extracted leading to enhanced ANN performance. The present results confirm that ANNs can provide a fast, accurate, and consistent methodology applicable to pharmaceutical fingerprinting.

[The mechanisms of hemodynamic shifts in normovolemic hemodilution]. / Mekhanizmy gemodinamicheskikh sdvigov pri normovolemicheskoi gemodiliutsii.

Normovolemic hemodilution is shown to activate adaptation mechanisms of the heart, regional circulation and microvasculature. This is accompanied by a decline in the total peripheral resistance, an increase in venous return and intensification of the regional tissue blood flow. An increase in the cardiac output is due to mobilization of the functional cardiac reserve and is not accompanied by intensification of the heart work. Accelerated pulmonary circulation in normovolemic hemodilution may lead to functional shunting and blood oxygenation disturbances in patients with anatomic and functional respiratory changes.

[Effect of controlled normovolemic hemodilution on the microcirculatory bed and the incidence of postoperative complications in abdominal surgery]. / Vliianie napravlennoi normovolemicheskoi gemodiliutsii na mikrotsirkuliatornoe ruslo i chastotu posleoperatsionnykh oslozhnenii v abdominal'noi khirurgii.

Directed normovolemic hemodilution with the preoperative reservation of part of the patients' blood considerably reduced the pathologic effect of the operative aggression on the microcirculation system, allowed reduction of the frequency of postoperative complications and increased the efficiency of treatment of 93 patients with diseases of organs of the abdominal cavity.