Prediction of gastric ulcers based on the change in electrical resistance of acupuncture points using fuzzy logic decision-making

Many theories of reflexology use ancient concepts which do not coincide with the modern medical terminology of anatomy, physiology and biophysics. This substantially reduces the trust of physicians in reflexology methods. During this research, several mathematical models for the interaction of the internal and biological active points of meridian structures have been proposed. The analysis of these models allows the specification of a list of gastric diseases for which reflex diagnostics and reflex therapy methods are most effective and also allows increasing the effectiveness of these procedures. It is shown that good results for the prediction and early diagnosis of diseases from the reaction energy of biologically active points (acupuncture points) are obtained using fuzzy logic decision making.     

Prediction and prenosological diagnostics of heart diseases based on energy characteristics of acupuncture points and fuzzy logic

Many theories of reflexology use ancient concepts which do not coincide with the modern medical terminology of anatomy, physiology and biophysics. This substantially reduces the trust of physicians in reflexology methods. During this research, several mathematical models for the interaction of the internal and biological active points of meridian structures have been proposed. The analysis of these models allows the specification of a list of heart diseases for which reflex diagnostics and reflex therapy methods are most effective and also allows increasing the effectiveness of these procedures. It is shown that good results for the prediction and early diagnosis of diseases from the reaction energy of biologically active points (acupuncture points) are obtained using fuzzy logic decision making.     

Experimental study of displays in contralateral acoustic reflex auditory stimulation

The results of an experimental study of manifestations of the acoustic reflex with contralateral auditory stimulation at a frequency of 1 kHz are presented, and the principal possibility and informativeness of its use for diagnosing the diseases of the organ of hearing are demonstrated. The principal difference of the developed approach is the use of polyharmonic signal for measuring acoustic reflex manifestations during contralateral stimulation, which allows accelerating the examination procedure.     

The effects of foot reflexology on pain and physiological indicators in children with leukemia under chemotherapy: a clinical trial study

BackgroundFoot reflexology is a popular complementary medicine method; however, previous studies have shown conflicting results. This study aimed to investigate the impact of foot reflexology on pain and physiological responses caused by intrathecal injection of chemotherapy drugs in children with leukemia.Materials and methodsThis clinical trial included 80 children with leukemia. The participants received 20 min foot reflexology (10 min each foot). The primary measured outcomes included pain and physiological indicators (blood pressure and heart rate).ResultsThe results showed that foot reflexology had a significant effect on reducing pain (p = 0.002) and improving physiological indicators [blood pressure (p = 0.002) and heart rate (p = 0.003)].ConclusionBased on the results of the present study, which shows the positive effect of foot reflexology on the improvement of pain and physiological indicators, foot reflexology can be used as a complementary treatment along with conventional therapies.     

Tumor micro-ecology and competitive interactions

Three nested models describing the growth of individual subpopulations in a heterogeneous environment are described. The models represent the dynamics of two populations which compete, to varying degrees, for common resources. The first model describes growth in a totally non-competitive micro-environment, the second model describes an ecology in which competition is proportional to competitor population size, and the third model ecology extends the model described by Jansson & Revesz (1974), which allows one population to emerge from the other. The critical points for each model are defined using the isoclines derived from the Ordinary Differential Equations (ODE's) describing competitive growth. The critical points for each model are characterized by the signs of the eigenvalues of the variational matrix at each point. The theoretical results of the analysis show that a competitive model ecology with Verhulstian logistics allows four critical points: the origin which is a repeller, two competitive exclusion points, and an equilibrium state (Waltman, 1983). The extended model ecology of Jansson & Revesz (1974), allows three critical points: the origin which is a repeller, competitive exclusion of the first population, and an equilibrium point. Data from a human adenocarcinoma of the colon and murine mammary tumors are used as qualitative measures of the dynamics of the three micro-ecologies. Issues such as stochastic extension to model small populations either for clonal extinction or heterogeneous emergence are discussed.     

Mathematical modelling of neuronal dendritic branching patterns in two dimensions: application to retinal ganglion cells in the cat and rat

Sholl’s analysis has been used for about 50years to study neuron branching characteristics based on a linear, semi-log or log—log method. Using the linear two- dimensional Sholl’s method, we call attention to a relationship between the number of intersections of neuronal dendrites with a circle and the numbers of branching points and terminal tips encompassed by the circle, with respect to the circle radius. For that purpose, we present a mathematical model, which incorporates a supposition that the number of dendritic intersections with a circle can be resolved into two components: the number of branching points and the number of terminal tips within the annulus of two adjoining circles. The numbers of intersections and last two sets of data are also presented as cumulative frequency plots and analysed using a logistic model (Boltzmann’s function). Such approaches give rise to several new morphometric parameters, such as, the critical, maximal and mean values of the numbers of intersections, branching points and terminal tips, as well as the abscissas of the inflection points of the corresponding sigmoid plots, with respect to the radius. We discuss these parameters as an additional tool for further morphological classification schemes of vertebrate retinal ganglion cells. To test the models, we apply them first to three groups of morphologically different cat’s retinal ganglion cells (the alpha, gamma and epsilon cells). After that, in order to quantitatively support the classification of the rat’s alpha cells into the inner and outer cells, we apply our models to two subgroups of these cells grouped according to their stratification levels in the inner plexiform layer. We show that differences between most of our parameters calculated for these subgroups are statistically significant. We believe that these models have the potential to aid in the classification of biological images.     

Effect of acute melipramine administration on motor activity and defensive conditioned reflexes of passive and active avoidance in rats

The administration of threecyclic antidepressant melipramine to Wistar rats (15 mg/kg, intraperitonaly, 2 h before of experiments) increases time of an "open field" centre leaving. Thus melipramine does not influence horizontal and vertical activity, and also the number of bolus. At the development of a passive avoidance conditioned reflex melipramine significantly slows down realization of a unconditional mink reflex by untrained rats, increasing the latency of call in a dark compartment of the chamber. After training significant deterioration of a reflex reproduction is observed. At research of a defensive conditioned reflex of active avoidance melipramine worsens both development and reproduction of a reflex. The comparative analysis of the literary data of imipramine action on uptake of serotonine and noradrenaline and the analysis of the literary data on a role of these systems in the processes of learning and memory allows to suggest, that the effect of melipramine is connected mainly to amplification activity of serotoninergic system of a brain. It is supposed, that acute administration of melipramine creates emotionally negative state, worsens processes of learning and memory, strengthening mainly activity of a brain serotoninergic system. It specifies that serotoninergic system of a brain is system of punishment. Its activation interferes with formation and consolidation of connections between conditional and unconditional irritation.     

A Method of Estimation of Change Points in Multiphasic Growth Models

The least-squares estimation (LSE) of change points and the phase parameters is considered for two growth models with piecewise continuously connected exponential and stationary phases. The calculation of a LSE is reduced to the solution of a finite number of simpler least-squares problems for which methods of calculation are well known.     

Visual motion,binocular correspondence and binocular rivalry

The human pupillary control system has been the subject of interest to biologists and engineers as an example of a sensorimotor reflex which can be embedded in a control system paradigm. We present a nonlinear feedback model whose compact structure allows us to hypothesize possible physiological mechanisms which generate the proper behavior of the pupil system. The important pupil responses, including pupil size effect, asymmetry, and response to high-frequency stimuli, are defined. This model was simulated on a digital computer and comparisons to the paradigm experimental responses were performed, demonstrating a fit to each of the observed conditions. Improvements on previous models are discussed.     

Immunology of fungal infections: lessons learned from animal models

The continuing AIDS epidemic coupled with increased usage of immunosuppressive drugs to prevent organ rejection or treat autoimmune diseases has resulted in an increase in individuals at risk for acquiring fungal diseases. These concerns highlight the need to elucidate mechanisms of inducing protective immune responses against fungal pathogens. Consequently, several experimental models of human mycoses have been developed to study these diseases. The availability of transgenic animal models allows for in-depth analysis of specific components, receptors, and signaling pathways that elicit protection against fungal diseases. This review focuses on recent advances in our understanding of immune responses to fungal infections gained using animal models.     

Direct and Model Free Calculation of Force-Dependent Dissociation Rates from Force Spectroscopic Data

Force spectroscopy allows testing the free energy landscapes of molecular interactions. Usually, the dependency of the most probable rupture force on the force rate or the shape of the rupture force histogram is fitted with different models that contain approximations and basic assumptions. We present a simple and model free approach to extract the force-dependent dissociation rates directly from the force curve data. Simulations show that the dissociation rates at any force are given directly by the ratio of the number of detected rupture events to the time this force was acting on the bond. To calculate these total times of acting forces, all force curve data points of all curves measured are taken into account, which significantly increases the amount of information which is considered for data analysis compared to other methods. Moreover, by providing force-dependent dissociation rates this method allows direct testing and validating of any energy landscape model.     

Structural adaptations and mechanism of reflex bleeding in the larvae of the myrmecophilous ladybird Diomus thoracicus

Reflex bleeding is an effective defensive mechanism against predators. When attacked, some insects emit hemolymph, which coagulates, quickly entangling their aggressor. Bleeding occurs at weak intersegmental membranes or through dedicated organs, which can be associated or not with glandular cells.Here, we describe the behavior and morphological structures involved in reflex bleeding in the larvae of the ladybird, Diomus thoracicus, which are intranidal parasites of the ant Wasmannia auropunctata. The larvae are tolerated by the ants thanks to odor mimicry, but some rare aggressive ant behaviors were observed that trigger reflex bleeding both at a pair of thoracic tubercles and a pair of posterodorsal abdominal humps. No glandular structure was found in association with these emission points, which suggests that the material emitted was hemolymph only. A 3D reconstruction suggested that reflex bleeding seems to be controlled by muscles whose contraction increases the internal hydrostatic pressure and pushes the hemolymph into a funnel-like structure with an opening to the outside. In D. thoracicus, the morphological structures involved in reflex bleeding are among the most complex and prominent described to date.     

Changes in stretch reflexes and muscle stiffness with age in prepubescent children.

Musculo-articular stiffness of the triceps surae (TS) increases with age in prepubescent children, under both passive and active conditions. This study investigates whether these changes in muscle stiffness influence the amplitude of the reflex response to muscle stretch. TS stiffness and reflex activities were measured in 46 children (7-11 yr old) and in 9 adults. The TS Hoffmann reflex (H reflex) and T reflex (tendon jerk) in response to taping the Achilles tendon were evaluated at rest and normalized to the maximal motor response (Mmax). Sinusoidal perturbations of passive or activated muscles were used to evoke stretch reflexes and to measure passive and active musculoarticular stiffness. The children's Hmax-to-Mmax ratio did not change with age and did not differ from adult values. The T-to-Mmax ratio increased with age but remained significantly lower than in adults. Passive stiffness also increased with age and was correlated with the T-to-Mmax ratio. Similarly, the children's stretch reflex and active musculoarticular stiffness were significantly correlated and increased with age. We conclude that prepubescent children have smaller T reflexes and stretch reflexes than adults, and the lower musculoarticular stiffness is mainly responsible for these smaller reflexes, as indicated by the parallel increases in reflex and stiffness.     

Antigen receptor signaling in the rheumatic diseases

Antigen receptor signaling in lymphocytes has been clearly implicated in the pathogenesis of the rheumatic diseases. Here, we review evidence from mouse models in which B-cell and T-cell signaling machinery is perturbed as well as data from functional studies of primary human lymphocytes and recent advances in human genetics. B-cell receptor hyper-responsiveness is identified as a nearly universal characteristic of systemic lupus erythema-tosus in mice and humans. Impaired and enhanced T-cell receptor signaling are both associated with distinct inflammatory diseases in mice. Mechanisms by which these pathways contribute to disease in mouse models and patients are under active investigation.     

Effect of the dry-cold season dormancy on the tonic and phasic neural control of heart rate in the toad, Bufo paracnemis

This work examined basal heart rate and autonomic cardiac tone as well as sympathetic cardiac reactivity to hypotension induced by systemic nitroprusside injection in dormant toads (dry-cold season), Bufo paracnemis, comparing the values with those of toads collected during the active months (hot-rainy season). Autonomic tone was calculated according to the method of Lin and Horwath ('72), which allows its evaluation as a percentage of intrinsic heart rate. Specimens were maintained in an outdoors terrarium except for the week preceding surgery, when they were transferred to indoor nonclimatized tanks. The heart rate of dormant toads (27.8 +/- 2.7 beats/min) was lower than that of active toads at rest (38.6 +/- 2. 3). Cholinergic tone was higher than adrenergic tone both in active (26.2% and 7.8%, respectively) and aestivated (19.5% and 4.8%, respectively) animals. Thus, cholinergic tone and adrenergic tone were both lower in dormant animals. The reflex tachycardia elicited by nitroprusside-induced hypotension was lower in aestivated toads (9.3 +/- 0.9 beats/min) when compared to active toads (19.9 +/- 1.0), indicating a reduced sympathetic reactivity. Nitroprusside-induced hypotensions were not different in the two groups. We conclude that at rest Bufo paracnemis heart is under the influence of a double cholinergic and adrenergic tone, and that both influences, as well as the reflex adrenergic reactivity to the unloading produced by nitroprusside-induced hypotension, are reduced in aestivated toads.     

Analysis of Nonlinear Gene Expression Progression Reveals Extensive Pathway and Age-Specific Transitions in Aging Human Brains

Several recent gene expression studies identified hundreds of genes that are correlated with age in brain and other tissues in human. However, these studies used linear models of age correlation, which are not well equipped to model abrupt changes associated with particular ages. We developed a computational algorithm for age estimation in which the expression of each gene is treated as a dichotomized biomarker for whether the subject is older or younger than a particular age. In addition, for each age-informative gene our algorithm identifies the age threshold with the most drastic change in expression level, which allows us to associate genes with particular age periods. Analysis of human aging brain expression datasets from three frontal cortex regions showed that different pathways undergo transitions at different ages, and the distribution of pathways and age thresholds varies across brain regions. Our study reveals age-correlated expression changes at particular age points and allows one to estimate the age of an individual with better accuracy than previously published methods.     

Tertiary templates for the design of diiron proteins.

Diiron proteins represent a diverse class of structures involved in the binding and activation of oxygen. This review explores the simple structural features underlying the common metal-ion-binding and oxygen-binding properties of these proteins. The backbone geometries of their active sites are formed by four-helix bundles, which may be parameterized to within approximately 1 A root mean square deviation. Such parametric models are excellent starting points for investigating how asymmetric deviations from an idealized geometry influence the functional properties of the metal ion centers. These idealized models also provide attractive frameworks for de novo protein design.     

Population genetics models of common diseases

The number and frequency of susceptibility alleles for common diseases are important factors to consider in the efficient design of disease association studies. These quantities are the results of the joint effects of mutation, genetic drift and selection. Hence, population genetics models, informed by empirical knowledge about patterns of disease variation, can be used to make predictions about the allelic architecture of common disease susceptibility and to gain an overall understanding about the evolutionary origins of such diseases. Equilibrium models and empirical studies suggest a role for both rare and common variants. In addition, increasing evidence points to changes in selective pressures on susceptibility genes for common diseases; these findings are likely to form the basis for further modeling studies.     

Tremor and other oscillations in neuromuscular systems

A model has been analyzed which is based on recent experimental evidence concerning the properties of muscles and the sensory feedback pathways from muscles. Damped oscillations can arise in the absence of sensory feedback due to the interaction of a muscle with inertial loads. These mechanical oscillations can have a wide range of frequencies depending on the inertial and elastic loads that are attached to the muscle. Small amounts of sensory feedback will tend to reduce deviations from a steady muscle length, but larger amounts of feedback can produce oscillations. The frequency of these reflex oscillations is determined by the properties of the muscle and feedback pathway, and is rather independent of load. If the strength of the sensory feedback is sufficient, either the mechanical oscillations or the reflex oscillations or both can grow, rather than decay, with time. The growth of these oscillations is limited by saturation non-linearities in the muscle receptors and the muscle itself, so that the oscillations approach a steady amplitude and frequency. Using typical properties of muscles and spinal reflex pathways, the frequency of reflex oscillations will be within the range 8–12 Hz found for physiological tremor. With the longer latency found for supraspinal reflexes, oscillations will occur in the range 4–6 Hz which is characteristic of Parkinson's and cerebellar diseases. The role of longer latency reflexes in the generation of these tremors is discussed.