Impedance therapy in rehabilitation of degenerative disc disease.

AIM: The aim of this work was to investigate the effects of Impedance Therapy (IT) in the treatment of degenerative disc disease (DDD) by confirming the presence of the "disc grow-up" (DGU) phenomenon. METHOD: The set consisted of 55 patients with DDD with the average age of 51.3 years divided into two groups ­ the experimental group and the control group. The experimental group consisted of 29 patients with the average age of 56.7 years. The control group consisted of 26 patients with the average age of 45.8 years. RESULTS: In the experimental group of patients with DDD, who received IT, the DGU phenomenon with a success rate of 76 % was observed, with the average increase in the volume of the intervertebral disc of 31 % (p < 0.000). In the control group of patients receiving the standard electrotherapy, the DGU phenomenon was not proven ­ the DDD progressed normally with the mean volume reduction of 15 % (p < 0.000). CONCLUSIONS: Degenerative disc disease, as a disease of modern civilization, is treatable. It can be concluded that the theory that degenerative disc changes are irreversible was disproven by the impact of impedance therapy (Tab. 5, Ref. 14)

An application of both principal dynamic modes (PDM) and statistics for rehabilitation estimation related to the patients after ischemic brain stroke.

Ischemic Brain Stroke is considered to be one of the most significant reason causing mortality of patients. During first 60 days after brain stroke some critical symptoms are localized. Eventual registration of physiological parameters or biomedical signals e.g. heart rate variability within that time results in extremely difficult interpretation, most likely at the certain border of commonly understand sense. Therefore proper rehabilitation of such patients associated with well estimated results is very important as significantly decreases their mortality and leaves them in the highest possible well being. Due to rather bad quality of registered signals the need of more sophisticated processing method is necessary. The paper presents application of PDM for decomposition of HRV signals spectrum and separate estimation of behavior of both sympathetic and parasympathetic nervous activity. Simple ANOVA test applied for properly prepared data proved the anticipated results concerning significant difference of certain parameters e.g. sympatho-vagal balance estimated within mentioned 60 days period.

Computer and physical modeling of blood circulation pump support for a new field of application in palliative surgery.

OBJECTIVES: One of the most popular palliative procedures performed to increase pulmonary blood flow in children with congenital heart defects is a shunt operation (Blalock-Taussig graft or Glenn procedure), which creates the new blood channel to the pulmonary artery. The main problem with this kind of surgery is poor shunt effectiveness and the lack of possibility to regulate the flow. The aim of this work is to use advanced computer simulation methods to study the effectiveness of a new idea to introduce a small axial blood pump into a Blalock-Taussig (B-T) or Glenn shunt in order to control the blood flow and prevent any increase in the graft stenosis. METHODS: Physical and computer 3-D simulation based on a finite element mesh (FEM) model was applied. Studies for optimization of the shunt and hybrid shunt with pump were performed for different stages of the disease. RESULTS AND CONCLUSION: The graft with the axial pump creates good conditions for the vascular system and pulmonary artery blood flow as well as regulating blood pressure under variable conditions caused by palliative procedures. Its use permits the afterload of the left heart ventricle to be decreased. A palliative procedure is only a temporary solution. When a child grows, while the graft size is fixed, the blood flow through this graft may be not sufficient under changing hemodynamic conditions. The use of an axial pump for regulating the blood flow volume, during palliative procedures, allows to obtain the optimal flow conditions in pulmonary artery and safely wait on the final cardiac surgery correction later. However, the use of a pump mounted inside the graft increased hemodynamic resistance, which caused the flow to decrease up to 70% in the graft when the axial pump was not working.

Polish cardio-robot 'Robin Heart'. System description and technical evaluation.

BACKGROUND: This paper presents the mechanical structure and control system of the Polish cardio-robot Robin Heart (RIH). METHODS: The Polish project with cardiac surgery robots started in 2000. It was supported by the team from the Foundation of Cardiac Surgery Development, Zabrze, in cooperation with research centers in Lodz and Warsaw. So far three prototypes, RH0, 1 & 2, of the Robin Heart robots family have been designed, constructed and tested. In addition many diagnostic systems have been constructed to aid with the assessment of robot performance. RESULTS: The main focus of this article examines the technical evaluation of our prototypes, based on laboratory test results of both the mechanical and control aspects of the telemanipulator systems. CONCLUSIONS: The presented test results of both mechanical and electrical aspects of Robin Heart telemanipulator systems, show significant progress both in a mechanical and control viewpoint, along with an improvement in the characterisation of the test parameters.

Hybrid feature vector extraction in unsupervised learning neural classifier.

Feature extraction and selection method as a preliminary stage of heart rate variability (HRV) signals unsupervised learning neural classifier is presented. Multi-domain, mixed new feature vector is created from time, frequency and time-frequency parameters of HRV analysis. The optimal feature set for given classification task was chosen as a result of feature ranking, obtained after computing the class separability measure for every independent feature. Such prepared a new signal representation in reduced feature space is the input to neural classifier based on introduced by Grosberg Adaptive Resonance Theory (ART2) structure. Test of proposed method carried out on the base of 62 patients with coronary artery disease divided into learning and verifying set allowed to chose these features, which gave the best results. Classifier performance measures obtained for unsupervised learning ART2 neural network was comparable with these reached for multiplayer perceptron structures.

Supervised and Unsupervised Learning Systems as a Part of Hybrid Structures Applied in EGG Signals Classifiers.

This paper aims at investigating an unsupervised learnt neural networks in classifier applications and comparing them to supervised perceptron type nets. The proposed solutions focus on combing the time-frequency preliminary analysis by means of wavelet transform with application of self organizing maps. Using wavelet transform as a feature extraction tool allowed to reveal important parameters included both in time and frequency domain of non-stationary electrogastrographic signals, which were classified in elaborated systems. Proposed structures were tested using the set of clinically characterized EGG signals of 62 patients, as cases with different level rhythm disturbances from bradygastria up to tachygastria together with some artifacts of non-stationary character such as muscle thrill etc. Additionally similar control group of healthy patients was analyzed. The results of the proposed methodology are illustrated in the measure of sensitivity and specificity, where the best classifier based on Kohonen maps with preliminary wavelet processing reached the performance above 90%.

Physical and computer modelling of blood flow in a systemic-to-pulmonary shunt.

UNLABELLED: The aim of this work was the application of computer and physical in vitro simulation methods for estimating surgery procedure hemodynamics. The modified Blalock-Taussig (mB-T) palliative surgical procedure is performed to increase the pulmonary blood flow in children with congenital heart defects. Such a systemic-to-pulmonary shunt yields substantial modification in the blood flow within the large blood vessels. The objective of the present study was to investigate basic characteristics of the flow, flow pattern and pressure-flow efficiency, before and after opening of the mB-T graft. METHODS: The model was based on the vessel geometry obtained from the Visible Human Project and included the arch of aorta, the three arteries branching from the arch, the pulmonary trunck, and the left and right pulmonary arteries. The graft was added between the left subclavian artery and the left pulmonary artery. The glass model of the vessels was produced and investigated in a physical model of the cardiovascular system with an artificial ventricular device as the blood pump. Flow rate and hydrostatic pressure were measured at the inlet to and outlets from the glass model and in a few points within the system. Laser flow visualization was also performed. Computer simulations were done using the boundary conditions from the physical model. RESULTS: The opening of the mB-T graft changed flow distribution in all branches (including inflow). A complex flow pattern with large eddies and channelling of the flow in the vicinity of the graft and within it was observed in flow visualization and in computer simulations. Because of that complexity the local measurements of hydrostatic pressure at the vessel wall could not predict the average flow rate. The reversed flow in the graft was observed during the systole. CONCLUSIONS: The complex flow pattern developed in the physical model of the mB-T graft. The channelling of the flow and the formation of large eddies may yield high shear stress and modify blood properties. The rigid wall model can describe only some flow characteristics observed in vivo. Computer simulation is a very fast and accurate method which permits earlier qualification of cardiac surgeons on how to change cardiac vascular blood flow after operations.

An improvement of unsupervised hybrid biomedical signal classifiers by optimal feature extraction in system preliminary layer.

In this paper we try to place emphasis especially on the feature extraction stage of classification procedure, where new feature vectors obtained from a high-dimensional data space, which the best match the analysed classification task are proposed. Based on multilevel Mallat wavelet decomposition, parameters obtained directly from the wavelet component as well as feature resulting from energy and entropy analysis are tested. In classifier part of proposed hybrid systems, unsupervised learning systems with self organizing maps (SOM) and adaptive resonance networks (ART2) are verified. T-F methods and particularly wavelet analysis was chosen as feature extraction tool because of its ability to deal with non-stationary signals. It is important to take into consideration, that heart rate variability (HRV) signals, which were classified in elaborated systems are nonstationary and have important parameters included both in time and frequency domain. Proposed structures were tested using the set of clinically characterized heart rate variability (HRV) signals of 62 patients, as cases with a coronary artery disease of different level. Additionally similar control group of healthy patients was analyzed. Whole database was divided into learning and verifying set. Results showed, that the new HRV signal representation obtained in the space created by the feature vector based on Shannon entropy of Mallat component energy distribution gave the best classifier performance with ART2 neural structure used in classifier part of described hybrid system.

Robin Heart 2003--present state of the Polish telemanipulator project for cardiac surgery assistance.

The Polish telemanipulator (Robin Heart), for use in cardiac surgery, has been realized by the Foundation of Cardiac Surgery Development in Zabrze, Poland, in cooperation with specialists from the Technical University of Lodz and Warsaw University of Technology. The brief history of robotic surgery and fundamental advantages of employing robots in this field--safe, reliable and repeatable operative results with less patient pain, trauma and recovery time--follow the assumptions of the Polish Cardio-Robot project. The cardiac surgery robot, Robin Heart, is an original construction with a segment type structure which allows the various combination of its parts for different types of surgery. The telemanipulator for cardiac surgery will consist of two arms equipped with tools and one arm holding the camera. Several models suitable for surgeon contact systems, using the experience of centers designing the artificial hand and haptic systems have been worked out. The detailed mechanical analysis and original construction of main parts of the robot and development of the surgical planning system are presented in further sections.

Role of redox-active iron ions in the decomposition of S-nitrosocysteine in subcellular fractions of porcine aorta.

We recently reported that degradation of S-nitrosocysteine in homogenates of porcine aorta increased severalfold in the presence of Mg2+ ions [Kostka, P., Xu, B. & Skiles, E.H. (1999) J. Cardiovasc. Pharmacol. 33, 665-670]. The objective of the present study was to examine this in greater detail. The rate of S-nitrosocysteine degradation by aortic homogenates in the presence of Mg2+ ions exhibited differential sensitivity to chelators of iron ions. Terpyridine and diethylenetriamine penta-acetic acid (5-500 microM) caused a concentration-dependent inhibition of S-nitrosocysteine decay, whereas deferoxamine (100 microM) was ineffective. o-Phenanthroline (250 microM), a selective chelator of Fe2+ ions, potentiated the reaction at low initial concentrations of S-nitrosocysteine (< or = 15 microM) and inhibited the reaction at higher concentrations. The inhibitory effects of o-phenanthroline were related to suppression of S-nitrosocysteine decay by cysteine-mediated reduction of Fe3+. In the presence of o-phenanthroline, S-nitrosocysteine decomposition followed saturable kinetics with K0.5 = 3.8 +/- 0.3 microM and h = 1.8 +/- 0.1 (mean +/- SE, n = 4). Comparison of the rates of S-nitrosocysteine decay in different subcellular fractions showed selective association with the cytosolic fraction, as documented by copurification with lactate dehydrogenase activity. At non-limiting concentrations of S-nitrosocysteine, the rate of degradation in the cytosolic fraction was 4.1 +/- 0.3 nmol.min-1.(mg protein)-1 (n = 4). It is concluded that the cytosolic fraction of porcine aorta contains a protein factor, presumably an enzyme, capable of catalyzing heterolytic decomposition of the S-NO bond of S-nitrosocysteine in a process involving redox cycling of iron ions.

Formation of peroxynitrite during thiol-mediated reduction of sodium nitroprusside.

Aerobic incubations of equimolar concentrations (5-500 microM) of sodium nitroprusside (SNP) and dithiothreitol (DTT) carried out at pH 7.4 in the absence of light caused a concentration-dependent increase in the rates of oxidation of dihydrorhodamine-123. The enhancement of the rates of oxidation under such conditions was only partially sensitive to the inhibition by 100 mM dimethyl sulfoxide implying the involvement of both peroxynitrite and hydroxyl radicals in the observed effects. The oxidation of dihydrorhodamine-123 in the presence of SNP and DTT was nearly completely abolished by superoxide dismutase (20 U/ml). It was found that such an effect of the enzyme was related primarily to the stabilization of an intermediate of SNP reduction formed upstream to the liberation of nitrosonium ligand. Increased rates of oxidation of dihydrorhodamine-123 were also observed during the reduction of SNP with either L-cysteine or glutathione. It is concluded that thiol-mediated reduction of SNP under aerobic conditions is accompanied by the formation of oxygen-derived free radicals. Nitrosonium ligand liberated from the product(s) of SNP reduction is, under such conditions, converted to peroxynitrite.

Degradation of S-nitrosocysteine in vascular tissue homogenates: role of divalent ions.

The objective of the study was to inquire about the mechanism(s) involved in the catabolism of S-nitrosothiols by vascular tissue under in vitro conditions. Incubations of S-nitrosocysteine (CYSNO) or S-nitrosoglutathione (GSNO) with homogenates isolated from porcine aortic smooth muscle resulted in only a marginal depletion of S-nitrosothiols from the reaction mixtures, which became statistically significant at relatively high concentrations of homogenate (> or =300 microg of protein/ml). Degradation of CYSNO (but not GSNO) was found to be potentiated several-fold by millimolar concentrations of either Mg2+ or Ca2+ ions. Under such conditions, the degradation of CYSNO was significantly suppressed by the removal of proteins by ultrafiltration (>80% inhibition) and eliminated completely by the alkylation of thiol groups with 1 mM N-ethylmaleimide. The potentiating effect of divalent ions on the degradation of CYSNO was insensitive to 0.1 mM neocuproine (selective chelator of Cu+ ions), although it was enhanced in the presence of 0.1 mM o-phenanthroline (selective chelator of Fe2+ ions). It is concluded that the degradation of CYSNO by tissue homogenate involves the interaction with protein-bound sulfhydryl groups, which is stimulated by Mg2+ or Ca2+ ions. The potentiating effect of o-phenanthroline suggests that the liberation of the nitrosonium moiety in such a process may be accompanied by its transfer to sulfur center(s) by transient formation of dinitrosyl-iron complexes.

Superoxide-mediated decomposition of biological S-nitrosothiols.

Incubation of S-nitrosocysteine or S-nitrosoglutathione (5-100 M) in the presence of a generator of superoxide (xanthine/xanthine oxidase) resulted in a time-dependent decomposition of S-nitrosothiols and accumulation of nitrite/nitrate in reaction mixtures. Quantitatively, the amounts of nitrite/nitrate represented >90% of nitrosonium equivalent of S-nitrosothiols degraded during the incubation. The reaction rates were unaffected by the presence catalase (1 unit/ml). Kinetic analysis showed that the degradation of S-nitrosothiols in the presence of superoxide proceeded at second order rate constants of 76,900 M-1 s-1 (S-nitrosocysteine) and 12,800 M-1 s-1 (S-nitrosoglutathione), respectively, with a stoichiometric ratio of 1 mol of S-nitrosothiol per 2 mol of superoxide. The findings provide the evidence for the involvement of superoxide in the metabolism of S-nitrosothiols. Furthermore, substantially slower reaction rates of superoxide with S-nitrosothiols relative to the reaction rate with NO are consistent with the contention that the transient formation of S-nitrosothiols in biological systems may protect NO from its rapid destruction by superoxide, thus enabling these compounds to serve as carriers or buffers of NO.

Fluorometric detection of biological S-nitrosothiols.

A technique is presented for the quantitative detection of S-nitrosothiols formed by model biological thiols, cysteine, glutathione, and serum albumin. The technique is based on the detection of fluorescent compound 1-[H]-naphthotriazole formed between 2,3-diaminonaphthalene and nitrous acid released from S-nitrosothiols by treatment with mercuric chloride in an acidic environment. Concentration of S-nitrosothiols is determined from the difference in fluorescent signal (excitation/emission wavelengths of 363 nm/450 nm, respectively) observed in the presence and absence of 0.18 mM HgCl2. The yield of the reaction between 2,3-diaminonaphthalene and nitrous acid released from the S-NO bond by HgCl2 approaches 90-100% as documented by simultaneous assays of S-nitrosothiols by uv spectrophotometry and by Saville method. The assay can be applied to the analysis of mixtures containing excess of thiol and/or nitrite at neutral pH by pretreatment of samples with N-ethylmaleinimide and/or ammonium sulfamate, respectively. In analysis of S-nitrosothiols in protein-containing mixtures, HgCl2-mediated release of nitrous acid in the presence of 2,3-diaminonaphthalene is followed by neutralization of samples and precipitation of protein with 0.5 M 5-sulfosalicylic acid. The fluorometric assay is carried out at an excitation wavelength of 380 nm to eliminate the background fluorescence of 5-sulfosalicylic acid observed at lower wavelengths. The technique offers simple and rapid determination of S-nitrosothiols in complex reaction mixtures with the detection limit at low nanomolar concentrations.

[Facial eosinophilic granuloma. Healing with cryosurgical therapy]. / Granuloma eosinophilicum faciale. Abheilung unter kryochirurgischer Therapie.

A case of eosinophilic granuloma facial is presented in which the lesions have been successfully treated by cryotherapy, healing with slight pigmentation. Since this disease appears to be difficult to treat, a great many forms of therapy have been proposed in the literature. These will be discussed with the results presented.

Nitric oxide synthase in the autonomic nervous system of canine ileum.

The synaptosomes from canine ileal deep muscular plexus possess a nitric oxide (NO)-sensitive soluble guanylate cyclase, as demonstrated by approximately 3- to 4-fold elevation of synaptosomal cyclic GMP levels in the presence of either 1 mM sodium nitroprusside or L-arginine (20-1,000 microM) plus 1 mM NADPH. The activating effect of L-arginine on synaptosomal soluble guanylate cyclase was related to its enzymatic conversion to citrulline by NO synthase. The synaptosomal NO synthase was found to exhibit both calcium-independent and calcium/calmodulin-dependent components accounting for approximately 2- to 2.5-fold and 7- to 8-fold increases in the basal activity, respectively. The absolute magnitude of these activities was several-fold greater compared to the activities observed in the isolated cells of circular smooth muscle. The synaptosomal Ca-independent and Ca/calmodulin-dependent NO synthase activities were inhibited by methylene blue and L-NG-arginine methyl ester. The NO synthase activity was also attenuated in the presence of cyclic AMP (10 microM). Such an inhibition was related primarily to the suppression of Ca-independent activity. The ability of enteric nerves to generate NO from L-arginine strongly suggests the involvement of this process in the biochemical mechanisms underlying the neurogenic control of intestinal motility.

[The Budapest agglomeration, 1980-1990]. / Budapesti agglomeracio, 1980-1990.

"The study analyses the development of Budapest and [the] 6 towns and 37 communes forming its conurbation between 1980 and 1990." Consideration is given to the city's population dynamics; housing conditions, including availability of utilities, transportation, telecommunications, and retail stores; health conditions of the population; and educational opportunities for residents. (SUMMARY IN ENG AND RUS)

Prejunctional muscarinic receptors in the deep muscular plexus of canine ileum: comparison with smooth muscle receptors.

Prejunctional muscarinic receptors from the deep muscular plexus of canine ileum were studied, and their properties were compared with those of the postjunctional receptors of the circular smooth muscle. In the purified synaptosomal fraction (a fraction containing primarily the axonal varicosities of deep muscular plexus), the muscarinic ligand N-[3H]methylscopolamine labeled an apparently homogenous population of receptors (nH = 1) with a Kd of 2.7 nM and a Bmax of 195 +/- 44 fmol/mg protein (mean +/- S.D., n = 4). These receptors showed a high affinity for the M3/M1-selective antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide (pKi = 7.41); in contrast, the pKi values of pirenzepine (5.60), methoctramine (5.65) and AF-DX 116 (5.21) implied little selectivity for these subtypes. The binding properties of muscarinic receptors in the synaptosomal fraction were different from the binding properties of muscarinic receptors in the purified circular smooth muscle plasma membranes. Most notably, the circular smooth muscle receptors had significantly lower affinity for N-[3H]methylscopolamine (Kd = 16 nM) with a Bmax value of 2088 +/- 276 fmol/mg. The affinities of the M2 subtype-selective muscarinic antagonists methoctramine and AF-DX 116 were similar in both membrane preparations. The receptor population associated with the deep muscular plexus synaptosomal fraction was linked to the inhibition of adenylate cyclase activity, as demonstrated by a concentration-dependent, atropine-sensitive inhibition of the forskolin-stimulated enzyme in the presence of muscarinic agonists carbachol and oxotremorine. Based on the pharmacological observations presented here, the prejunctional muscarinic receptors in the axonal varicosities of deep muscular plexus are different from the postjunctional receptors present in the circular smooth muscle.