[Main anthropometric indicators of children and adolescents living in the Chuvash Republic in the dynamics of 137 years]

Anthropometric studies conducted in 1884, 1928, 1946, 1965 and 1999 to study the characteristics of growth and weight indicators of children living in the territory of modern Chuvashia, partly reflected the influence of the living conditions of children in certain historical periods of the country's development: revolutions, civil and domestic wars, post-war stabilization, «perestroika». Over the last 22-year period, from 1999 to 2021, there has been the largest increase in the growth rate of indicators of the physical development of children and adolescents, which is considered as a positive trend, a manifestation of ongoing acceleration processes. It was revealed that in modern children, physiological growth jumps in comparison with their peers in 1884, 1930, and 1999 occur earlier - in the prepubertal period.

[Methodic approaches to evaluation of individual life quality of coal industry workers]

To study influence of social factors on life quality of coal industry workers, the authors designed a new method assessing individual life quality in miners, based on life quality assessment suggested by WHO. According to the study, life quality value averaged 27.7% in the examinees. According to the scale presented, average life quality level in the miners is low. Variability of life quality levels in the miners is determined mostly by social satisfaction index and health satisfaction index. Anxiety about health and quality of social care appeared to be main factors of low life quality in coal industry workers. Keywords: life quality, coal industry workers, psychologic component of health.

[Medical treatment in occupational diseases as a prospective type of care for coal industry workers (review of literature)]

The review covers prospects of pharmaceutic care implementation for coal industry workers and problems of interactions between pharmaceutical workers and medical establishment officers in optimization of medical and pharmaceutic care for miners. The authors present value of pharmaceutic care in treatment of specific diseases, where pharmaceutic care is defined as system providing pharmacotherapy for better results and improving life quality of patients.

[Methodic approaches to pharmaco-economic evaluation of vibration disease inpatient treatment in miners]

The authors justify pharmaco-economic evaluation of vibration disease inpatient treatment in miners, as miners' health improvement necessitates effective use of available means and implementation of economic management methods. Qualitative medical and pharmaceutic care in miners with vibration disease requires considerable financial, material and manpower resources of medical organization.

[Methodologic approaches to farmacologic economic analysis of actual inpatient treatment of occupational diseases]

To improve miners' health nowadays, effective application of available means and implication of economic management methods are necessary, as quality medical and pharmaceutic care for miners requires significant financial, material and working efforts both from the government and from every institution operating in health care.

[Forming a concept of pharmaceutic aid in occupational diseases]

The review covers aspects connected with formation of concept of pharmaceutic aid in occupational diseases. The authors emphasize problems of interactions between pharmacy workers and medical organizations officers for optimizing pharmaceutic aid. Prospects of the pharmaceutic aid concept implementation into treatment of specific diseases including occupational diseases in miners are shown.

Membrane Electromechanics in Biology, with a Focus on Hearing

Cells are ion conductive gels surrounded by a ~5-nm-thick insulating membrane, and molecular ionic pumps in the membrane establish an internal potential of approximately -90 mV. This electrical energy store is used for high-speed communication in nerve and muscle and other cells. Nature also has used this electric field for high-speed motor activity, most notably in the ear, where transduction and detection can function as high as 120 kHz. In the ear, there are two sets of sensory cells: the "inner hair cells" that generate an electrical output to the nervous system and the more numerous "outer hair cells" that use electromotility to counteract viscosity and thus sharpen resonance to improve frequency resolution. Nature, in a remarkable exhibition of nanomechanics, has made out of soft, aqueous materials a microphone and high-speed decoder capable of functioning at 120 kHz, limited only by thermal noise. Both physics and biology are only now becoming aware of the material properties of biomembranes and their ability to perform work and sense the environment. We anticipate new examples of this biopiezoelectricity will be forthcoming.

[Arterial hypertension and coronary heart disease: clinical and functional aspects]

The subjects of the study were 196 men with verified coronary heart disease (CHD). The subjects were divided into 4 groups: 1) patients without arterial hypertension (AH); 2) patients with mild AH, 3) patients with moderate AH, 4) patients with severe AH (SAH). All the patients were tested by means of veloergometry. The study found that the presence and severity of AH affected functional condition of cardiovascular system and clinical manifestations in patients with CHD. The appearance and aggravation of AH in CHD patients: 1) diminished clinical manifestations (angina), and elevated frequency of ECG signs of myocardial ischemia; there was significant growth of the proportion of patients with painless myocardial ischemia and ventricular arrhythmias associated with physical activity; 2) while causing moderate decrease of physical tolerance, substantially decreased the economy of cardiovascular system functioning, associated mostly with 'pressure overload"; pressor reaction effectiveness lowered; 3) worsened disturbances of recovery period, which manifested in prolongation of the time necessary for systolic pressure to return to initial level. These peculiarities were most prominent in patients with CHD and SAH, which allows considering this combination to be a new condition, requiring new approaches to evaluation of its clinical course and therapy.

[Primary osteosynthesis in pediatrics: possibilities and perspectives]

An analysis of results of conservative strategy of treatment of unstable diaphysial fractures of long tubular bones in schoolage children allowed to expand the indications to performance of osteosynthesis as a primary method of treatment (133 children). Extracortical osteosynthesis with planes by such criteria as efficiency, safety, profitability and quality of patient's life is thought to be preferable.

[Arterial hypertension and ischemic heart disease: clinico-echocardiographic aspects]

Doppler M-mode echocardiography was made in 156 males with ischemic heart disease (IHD) verified coronarographically. The patients were normotensive or had mild, moderate and severe arterial hypertension (AH) (groups 1, 2, 3 and 4, respectively). The groups were similar by functional anginal class. Echocardiographic findings were in many cases similar. This supports the hypothesis that IHD and AH are closely related. However, the addition of AH to atherosclerotic affection of the coronary artery or atherosclerosis rise in the presence of AH is associated with development of myocardial hypertrophy which is registered at echocardiography and correlates in severity with severity of AH. Myocardial hypertrophy is, on the one side, compensatory as it prevents dilation of the left ventricle and impairment of its contractility rising at later stage of the disease with depletion of the myocardial and coronary reserves, but, on the other side, it promotes diastolic dysfunction of the left ventricle, lowers its performance. The above phenomena are most pronounced in combination of IHD with severe AH. This combination presents a new qualitative state and, therefore, needs new approaches to its correction.

[Serum concentrations of trace elements and microcirculation during laser therapy for pneumonia]

The impact of laser therapy in the multimodality treatment for pneumonia on the serum levels of trace elements and microcirculation was studied. A total of 105 patients with pneumonia were examined. The patients were divided into 2 groups: 1) 68 patients received laser therapy and 2) 37 patients took drug therapy alone. There was a more substantial reduction in the permeability of cellular membranes, a significant increase in the serum levels of iron and chromium, better circulation at the expense of a vascular component. The above changes highly correlated with laboratory data and external respiratory function parameters.

Interaction of phospholipid bilayers with polyamines of different length

The tip-dip patch clamp method was used to study the effect of three polyamines, putrescine, spermidine and spermine, on bilayer lipid membrane (BLM) stability. Two kinds of mixed lipid-polyamine membranes were investigated. The poration voltage (V(p)), and the closed (sigma(cl)) and open (sigma(op)) state conductances for pure and polyamine-treated lipid membranes were determined by the method of current-voltage surfaces. It was demonstrated that putrescine and spermidine destabilized lipid membranes under all circumstances. BLM stabilization by spermine was observed when it was added to preformed membranes.

[Application of high information technologies in predicting outcomes of cardiovascular diseases]

The authors review their studies conducted for many years on cardiological prognostication in the context of the republican program "Cardiology" performed in the Udmurt Republic. The lines of the research and results obtained are described.

[An algorithm for construction of a mathematical model of coronary circulation disorders]

The paper shows how to improve the quality of diagnosing coronary heart disease (CHD). It proposes a mathematical model of coronary circulatory disorders, which is based on the definition of CHD as a cardiac abnormality caused by the imbalance of coronary blood flow and myocardial oxygen consumption, outlines an algorithm for construction of this model. With this model, a computer system has been designed for examining a patients with CHD, which permits the construction of a virtual model of coronary circulatory disorders.

Pores formed in lipid bilayers and in native membranes by nodularin, a cyanobacterial toxin

Nodularin (NODLN), a cyclic pentapeptide hepatotoxin from the cyanobacterium Nodularia spumigena, induces pores in bilayers of diphytanoyl lecithin (DPhL) and in locust muscle membrane. NODLN increases the surface pressure of a DPhL monolayer; except when the surface pressure of the monolayer is high when the toxin causes a reduction of this parameter. NODLN pores exhibit many open conductance states; the higher state probabilities increasing when the transmembrane pressure is increased. The results from these studies are discussed in terms of two models for a NODLN pore, a torroidal model and a barrel-stave model. The edge energy of the NODLN pore of 1.4 x 10(-12) J/m is determined.

Dip patch clamp currents suggest electrodiffusive transport of the polyelectrolyte DNA through lipid bilayers

Planar lipid bilayers formed from monolayers of diphytanoyl lecithin (DPhL) were found to interact with plasmid DNA (5.6 kbp; M(r) = 3.7 x 10(6)) leading to an increase in the conductance of the membrane. The association of DNA with a lipid bilayer greatly facilitates the transport of the small ions of the main salt KCl. The appearance of long-lived current levels, for instance, of 27.6 pA at Vm = +60 mV membrane voltage, where the actual contact (adsorption) is electrophoretically enhanced, suggests a locally conductive DNA/lipid interaction zone where parts of the DNA strand may be transiently inserted in the bilayer, leaving other parts of the DNA probably protruding out from the outer surface of the bilayer. At Vm = -60 mV, where DNA can be electrophoretically moved away from the membrane, the membrane current is practically zero. This current asymmetry is initially also observed at higher voltages, for instance at 200 mV. However, if the voltage sign (Vm = +200 mV) is changed after a transient positive current (approximately 15 pA) was observed, there is also now (at Vm = -200 mV) a finite negative current at the negative membrane voltage. Thus, it appears that at Vm = +200 mV the adsorbed parts of the polyelectrolyte DNA are not only transiently inserted in, but actually also electrophoretically pulled through, the porous zones onto the other membrane side leaving the bilayer structure basically intact. These data provide direct electric evidence for the electrophoretic transport of a highly charged and hydrated macromolecule, probably together with the associated gegen-ions, through the thin hydrophobic film of the lipid bilayer.

Mechanosensitivity of cell membranes. Ion channels, lipid matrix and cytoskeleton

Physical and biophysical mechanisms of mechano-sensitivity of cell membranes are reviewed. The possible roles of the lipid matrix and of the cytoskeleton in membrane mechanoreception are discussed. Techniques for generation of static strains and dynamic curvatures of membrane patches are considered. A unified model for stress-activated and stress-inactivated ion channels under static strains is described. A review of work on stress-sensitive pores in lipid-peptide model membranes is presented. The possible role of flexoelectricity in mechano-electric transduction, e.g. in auditory receptors is discussed. Studies of flexoelectricity in model lipid membranes, lipid-peptide membranes and natural membranes containing ion channels are reviewed. Finally, possible applications in molecular electronics of mechanosensors employing some of the recognized principles of mechano-electric transduction in natural membranes are discussed.

Flexoelectric effects in model and native membranes containing ion channels

An experimental study of flexoelectricity in model membranes containing ion pores and native membranes containing ion channels has been undertaken with the objective of determining the relationship, if any, between flexoelectricity and ion transport. Model membrane patches containing ion pores induced by a blue-green algal toxin, microcystin-LR, and locust muscle membrane patches containing potassium channels were studied using patch-clamp techniques. A correspondence was established between the presence of open channels and pores and the amplitude of the 1st harmonic of the total membrane current when the membranes or patches were subjected to pressure oscillations. The 2nd harmonic of the membrane current provided a measure of the amplitude of a membrane curvature induced by pressure, thus making it possible to determine the membrane flexoelectric coefficient. This study shows that flexoelectricity could be an effective driving force for ion transport through membrane pores and channels, thus further highlighting the possible biological significance of this mechano-electric phenomenon.

Pure and mixed lipid black foam films as models of membrane fusion

Black foam films (BFF) from water solutions of the phospholipid dilauroyl lecithin (DLL) with admixtures of palmitoyl lysolecithin (Lyso) were formed. Microscopic BFF were studied by the method of Scheludko and Exerowa. The formation probability for BFF and the BFF lifetime in a black state before film rupture were measured as functions of the film composition. At a fixed overal lipid concentration it was shown that an increased percentage of Lyso exponentially increased the lifetime of the film up to the CMC of Lyso. This stabilizing Lyso effect nicely corresponds with its stabilizing action on the waiting time for fusion of two contacting black lipid membranes (BLM), as found by Chernomordik et al. In contrast, Lyso is known to destabilize a single BLM. In this way we have found experimental proof of our earlier prediction that Lyso should have opposite effects on the lifetimes of BLM and BFF. In addition, we have shown for the first time that foam films made of lipids are a convenient model for monolayer membrane fusion studies. This model is characterized by its simplicity and experimental reliability and provides a means for quick screening of the fusogenic capacity of various amphiphilic and hydrophilic admixtures.

Curvature-electric effects in artificial and natural membranes studied using patch-clamp techniques

Methods for applying sound pressure to membrane patches formed at the tips of patch-clamp pipettes have been developed. Artificial membrane patches were formed from diphytanoyl phosphatidylcholine using a pipette dipping technique. Natural membrane patches were excised (inside-out mode) from collagenase-treated locust muscle membrane. Curvature-electric signals were registered under both voltage clamp and current clamp conditions. The phenomenon of flexoelectricity in membranes has previously been attributed to curvature-induced polarization originating from the liquid crystalline properties of membranes. The estimated magnitude (2 x 10(-18) C) of the flexoelectric coefficient of the artificial lipid bilayers is consistent with previous findings while that of the muscle membrane was in certain cases several times larger. The present study is the first to report on flexoelectricity in a natural membrane and raises the question of the biological significance of this phenomenon.

Is flexoelectricity the coupling factor between chemical energy and osmotic work in the pump? A model of pump

The following pump model is proposed. A gate is responsible for pump specificity. The actual driving force of the transport of ions against the electrochemical potential gradient is the electric field originating from an altered curvature of the phospholipid bilayer around the pump. The physical origin of this curvature-induced electric field arises from a basic liquid crystal property of lipid bilayers called flexoelectricity. Alterations occurring in phospholipid bilayer arrangement are due to changed conformation of protein; the main energy source of this change is ATP. Consequently, the energy of ATP is transformed, in our pump model, into osmotic work in following steps: ATP + protein (conformation I)----protein (conformation II)----alterations in phospholipid bilayer arrangement----electric field----active transport of ions. This model is the most simple one. In Na, K-pump there is a bidirectional ion transport. In our model of Na, K-pump three conformational states of pump proteins and two different electric fields formed sequentially in opposite directions are supposed.

Optical detection of phase transitions in simple and mixed lipid-water phases

A simple method for the detection of phase transitions in lipid-water systems by recording the intensity of the transmitted light through a sample placed between crossed polarizers as a function of the temperature was developed. A very small amount of lipid material is sufficient for its effective application. Two zwitterionic lipids in water, dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine (DPPE) as well as their mixtures were studied by means of this method. The results were compared with differential scanning calorimetry (DSC) data and a good correspondence was established. A phase diagram of the DPPC-DPPE mixture is constructed. This study also throws additional light on the nature of the 'pretransition' of DPPC.

[Application of mechanotronic transducers in experimental biological investigations]

Mechanotronic transducers applied usually in technical investigations for the measurement of displacements, tensions, pressures and other mechanical parameters have been studied to register the contractile activity of isolated organs (the frog heart ventricle, the rat ileum strips) and the blood pressure in anesthetized animals. It was found that the mechanotronic transducers are simple, convenient and reliable devices for such investigations.