Methodological approach for estimating the functional state of the body by the degree of fatigue

The functional state of firefighter (rescuers) from operational units of the Ministry of the Russian Federation for Affairs of Civil Defense, Emergencies and Disaster Relief (persons of an extreme profession, men from health groups I–II, 20–45 years old; n= 136) has been monitored under the conditions of a 24-h workday (WD) in the framework of an integrated study. It has been shown that the signs of acute fatigue appear in individual systems, while general fatigue is formed in the body as a whole. A methodological approach has been developed for estimating their functional state by rating the “general fatigue of the body,” including six methodically different techniques.     

Spectral assessment of the functional state of the stomach

The changes of the parameters of Fourier's transformations of electrogastrorhythmograms of humans after feeding are investigated as well as of dogs after vagotomy. The study has demonstrated that the method of myoelectronic electrical stimulation (with feedback) may be used for estimation of efficiency of vagotomy.     

A symmetry approach to electrocardiogram analysis

A qualitative characteristics of a symmetry of correlations in ECG parameters has been studied in experiments on rats with the adaptation syndrome and hypertonic patients (I-II stages). A geometrical model of cardiac cycle shaped as a rectangular triangle with temporal and amplitude ECG parameters as catheti. A total correlation between the ECG parameters is given: QT--QRS/QT--PQ.RR--PQ/RR--QRS = R--P/R--T = 1,309. In healthy individuals, the deviation from the ideal proportion constitutes less than 5%, and in patients with cardiovascular diseases, the deviations are substantial.     

A quantitative colorimetric method to evaluate the functional state of human polymorphonuclear leukocytes

The colorimetric assay previously described by Mosmann for the measurement of cell viability and proliferation has been modified for the assessment of the functional state of human polymorphnuclear cells (PMNs). The ability of PMNs to reduce the tetrazolium salt MTT to formazan reflects directly the degree of stimulation induced by various agents. The underlying mechanism of MTT-reduction to formazan seems to be similar to that of nitroblue tetrazolium (NBT)-reduction. In contrast to the NBT-reduction assay, the formazan produced from MTT can easily be measured by an ELISA reader. Parallel experiments revealed a qualitative correlation between the concentration of formazan produced from MTT and the concentration of cytochrome C reduced by PMNs. Although oxidative burst may not be the actual lytic mechanism in cellular cytotoxicity of PMN, we also observed an association between MTT-reduction capacity and the cytotoxic activity of PMNs from normal donors in antibody dependent cellular cytotoxicity. Our results indicate that the MTT-reduction assay can be employed to estimate the functional state of polymorphnuclear granulocytes.     

A rate distortion approach to protein symmetry

A spontaneous symmetry breaking argument is applied to the problem of protein folding, via a rate distortion analysis of the relation between genome coding and the final condensation of the protein molten globule that is, in spirit, analogous to Tlusty’s (2007) exploration of the evolution of the genetic code. In the ‘energy’ picture, the average distortion between codon message and final protein structure, under constraints driven by evolutionary selection, serves as a temperature analog, so that low values limit the possible distribution of protein forms, producing the canonical folding funnel. A dual ‘developmental’ perspective sees the rate distortion function itself as the temperature analog, and permits incorporation of chaperons or toxic exposures as catalysts, driving the system to different possible outcomes or affecting the rate of convergence. The rate distortion function appears constrained by the availability of metabolic free energy, with implications for prebiotic evolution, and a nonequilibrium empirical Onsager treatment provides an adaptable statistical model that can be fitted to data, in the same manner as a regression equation. In sum, mechanistic models of protein folding fail to account for the observed spectrum of protein folding and aggregation disorders, suggesting that a biologically based cognitive paradigm describing folding will be needed for understanding the etiology, prevention, and treatment of these diseases. The developmental formalism introduced here may contribute substantially to such a paradigm.     

Biofeedback training and human functional state control

Biofeedback (BFB) training paradigm has outstanding place among various approaches to non-phrarmacological human functional state correction. Being an universal way for voluntary self-regulation of physiological functions, it is characterized by efficacy, accessibility and absence of side effects. However, the lack of fundamental knowledge about the BFB mechanisms leads to existence of numerous difficulties and problems that seriously limit the BFB possibilities. Most difficulties seem to concern the problem of adequate choice of BFB type or parameter being voluntary controlled via feedback signals. Some ways to solve this problem are drown on the base of general systems theory. It is shown that BFB procedures could be especially effective in conditions of close interaction between the BFB mechanisms and the central regulatory mechanisms. Such interaction could be reacheb by utilization of certain characteristics of brain electrical activity reflected in the electroencephalogram (EEG). The most perspective seems to be the utilization of discrete narrow band EEG spectral components, individual resonance EEG oscillators or some correlates of human EEG amplitude modulation processes.     

Modeling transitions in body composition: the approach to steady state for anthropometric measures and physiological functions in the Minnesota human starvation study

Background

This study evaluated whether the changes in several anthropometric and functional measures during caloric restriction combined with walking and treadmill exercise would fit a simple model of approach to steady state (a plateau) that can be solved using spreadsheet software (Microsoft Excel^®). We hypothesized that transitions in waist girth and several body compartments would fit a simple exponential model that approaches a stable steady-state.

Methods

The model (an equation) was applied to outcomes reported in the Minnesota starvation experiment using Microsoft Excel's Solver^® function to derive rate parameters (k) and projected steady state values. However, data for most end-points were available only at t = 0, 12 and 24 weeks of caloric restriction. Therefore, we derived 2 new equations that enable model solutions to be calculated from 3 equally spaced data points.

Results

For the group of male subjects in the Minnesota study, body mass declined with a first order rate constant of about 0.079 wk^-1. The fractional rate of loss of fat free mass, which includes components that remained almost constant during starvation, was 0.064 wk^-1, compared to a rate of loss of fat mass of 0.103 wk^-1. The rate of loss of abdominal fat, as exemplified by the change in the waist girth, was 0.213 wk^-1.On average, 0.77 kg was lost per cm of waist girth. Other girths showed rates of loss between 0.085 and 0.131 wk^-1. Resting energy expenditure (REE) declined at 0.131 wk^-1. Changes in heart volume, hand strength, work capacity and N excretion showed rates of loss in the same range. The group of 32 subjects was close to steady state or had already reached steady state for the variables under consideration at the end of semi-starvation.

Conclusion

When energy intake is changed to new, relatively constant levels, while physical activity is maintained, changes in several anthropometric and physiological measures can be modeled as an exponential approach to steady state using software that is widely available. The 3 point method for parameter estimation provides a criterion for testing whether change in a variable can be usefully modelled with exponential kinetics within the time range for which data are available.

     

Ecosystemic structural–functional approach of the state and transition model

Objective: To contribute to the integration of key ecological concepts such as dynamic equilibrium, critical threshold, resistance and resilience to the ‘State and Transition Model’ (STM), in order to apply them in a more feasible way for rangeland management. Methods: Review and discussion of conceptual models and applied literature, including examples of rangeland dynamics. Results and Conclusions: We propose to enhance the STM considering two principal axes: (a) the x axis determined by structural ecosystem changes (vegetation and soil) and (b) the y axis determined by ecosystem functions and/or processes (recruitment, rain use efficiency). These axes define what we will call Structural–Functional State and Transition Model (SFSTM). Both axes of SFSTM make it possible to determine and quantify states and transitions, critical thresholds and to evaluate the resistance and resilience of an ecosystem to a given disturbance. The critical threshold is identified by structural and functional thresholds (x and y axes), thus defining the point where the ecosystem loses its resilience. Furthermore, in the supplementary file we provide examples with field data from Patagonia to illustrate the SFSTM. The proposed SFSTM has large implications for rangeland research and management, facilitating the understanding and integration of key concepts to enhance the STM. The identification of variables to assess structure and processes makes the model more useful.     

Kinetographic assessment of the functional state of healthy humans: A pilot study

An original method for assessing the human functional state (FS) is described. The method is based on stabilography in a sitting position. Changes in the position of the total center of pressure on a stabilographic support were monitored in 32 healthy subjects who were in an arbitrary sitting position, in the state of quiet wakefulness with the eyes open or closed. The obtained data were analyzed in terms of the theory of complex systems. The recorded signal was considered as an output of a complex, half-open biomechanical system responding to numerous external and internal stimuli. The necessary and sufficient set of parameters for qualifying the FS has been determined, and the ranges of normal values of these parameters have been estimated. The sensitivity of the method to changes in the FS and the individual stability of some calculated kinetographic parameters have been demonstrated. The method is applicable to studies in psychotherapy, perception psychology, operator performance, and neurological rehabilitation science.     

A comprehensive approach to visual and functional assessment of experimental vascular lesions in vivo

The role of metabolic factors derived from cardiac muscle in the development of reactive hyperemia after brief occlusions of the coronary circulation seems to be well established. However, the contribution of occlusion-induced changes in hemodynamic forces to eliciting reactive hyperemia is less known. We hypothesized that in isolated coronary arterioles changes in intraluminal pressure and flow, during and after release of occlusion (O/R), themselves via activating intrinsic mechanosensitive mechanisms, elicit release of vasoactive factors resulting in reactive dilations. Thus in isolated coronary arterioles (diameter: 88 +/- 8 microm) changes in diameter to changes in pressure or pressure plus flow (P+F) during and after a brief period (30, 60, and 120 s) of O/R of cannulating tube were measured by videomicroscopy. In response to both types of O/R, diameter first decreased, then, subsequently increased during occlusions. When only pressure was changed (from 80-10-80 mmHg), after release of occlusion, peak dilations increased as a function of the duration of occlusions. After flow was established (30 microl/min), O/R elicited changes in both pressure and flow (from 80-10-80 mmHg and from 0 to 30 microl/min). In these conditions, after the release of occlusions, not only the peak but also the duration of reactive dilation increased significantly as a function of the length of occlusions. The dilations during, and peak dilations after occlusions both in pressure and P+F protocols were significantly reduced by the inhibition of NO synthase with Nomega-nitro-L-arginine-methyl-ester (L-NAME) or by endothelium removal, whereas duration of postocclusion dilations were reduced by L-NAME or by endothelium removal only in P+F protocols. Furthermore, in both protocols, catalase significantly reduced the peak but not the duration of reactive dilations. Thus, mechanosensitive mechanisms that are sensitive to deformation, pressure, stretch, and wall shear stress elicit release of NO and H2O2, resulting in reactive dilation of isolated coronary arterioles.