[Molecular Aspects of Translational Cardiology in Vascular Wall Research].

Clinical-biochemical research of vascular wall hydrated state, water-electrolyte balance has broadened substantially our notions concerning initiation mechanism of vessel damages, methods of their prevention and treatment. Consecutive study of endothelial glycocalyx functioning, computational research of its interaction with oxidative stress, regulation of its state has been aimed at development of novel means of the vascular system protection. Mutual efforts of clinicians and scientists should contribute to the productivity of results of translational cardiology.

Subterahertz chaos generation by coupling a superlattice to a linear resonator.

We investigate the effects of a linear resonator on the high-frequency dynamics of electrons in devices exhibiting negative differential conductance. We show that the resonator strongly affects both the dc and ac transport characteristics of the device, inducing quasiperiodic and high-frequency chaotic current oscillations. The theoretical findings are confirmed by experimental measurements of a GaAs/AlAs miniband semiconductor superlattice coupled to a linear microstrip resonator. Our results are applicable to other active solid state devices and provide a generic approach for developing modern chaos-based high-frequency technologies including broadband chaotic wireless communication and superfast random-number generation.

[Experimental rationale for possible clinical use of biodialysis].

At biodialysis, the bloods of a patient and a donor simultaneously pass through the individual mass exchangers. The cavities of the dialyzing fluid of both mass exchangers hydraulically interconnected with recurculating transport medium. The metabolites accumulating in the patient's blood pass through the membrane to the transport medium and then the second membrane to the donor's blood and they are eliminated via his/her liver and kidney. At the same time, regression occurs: the substances required for normal vital activity move from the donor's body to the patient's one. Experiments on pigs in one of which both kidneys were removed yielded clearances of major toxic metabolites by approximately 2 times less than that at routine dialysis. Daily sessions of biodialysis ensured a satisfactory state and stable levels of metabolites. At biodialysis, the state did not deteriorate. In the other series of experiments, choledochus was ligated in one of the pigs and sessions of biodialysis were initiated following 24 hours. Daily sessions could achieve stabilization of the level of bilirubin within 135 micromol/l. In the donor pig, the level of bilirubin slightly increased. Its condition remained to be satisfactory.

[Hemodialysis with biological object].

The essence of the method of biodialysis (hemodialysis with biological object) developed and suggested by the authors for clinical use consists in that the healthy organism exerts, through a system of mass transfer, a therapeutic action on the sick organism. Blood from the affected and healthy organisms is perfused through individual mass exchangers (dialyzers, hemodiafilters and hemofilters), which are hydraulically connected by a circulating transport medium. Metabolites that accumulate in blood of the affected organism diffuse into the transport medium and, from there, into blood of the healthy organism, which metabolizes them. The reverse process occurs simultaneously: substances, whose concentration in blood of the sick organism is less versus the healthy organism, diffuse from blood of the healthy organism to blood of patient. The method suggested by us can be used in clinical practice for normalizing a variety of parameters in patients with hepatic and renal insufficiency. Besides, a number of substances can be transferred from the healthy donor to patient in the process of biodialysis, which opens promising potentialities for the treatment of many diseases.

[Electrochemical regeneration of the dialyzing solution]. / Elektrokhimicheskaia regeneratsiia dializiruiushchego rastvora.

The system with electrochemical regeneration (ER) of the dialyzing solution functions as effectively as a conventional hemodialysis system: ER eliminates creatinine and potassium ions, is inferior in eliminating urea and non-organic phosphorus but superior to hemodialysis in elimination of middle-size molecular toxins. ER enables continuous purification of dialyzing solution, electrolyzer is a constant element of the regeneration system, produced by electrolyzer sodium hypochlorite warrants the system self-sterilization. ER works without systems of water purification, water communications and dialyzer concentrate that is why the procedure of detoxication can be performed outside specially equipped laboratories.

[Electrochemical regeneration of dialysis solution in experimental and clinical conditions]. / Elektrokhimicheskaia regeneratsiia dializiruiushchego rastvora v éksperimente i klinike.

The authors have created a new system for electrochemical regeneration of dialysis solution and conducted 67 experiments using a model solution. Two groups of patients with terminal renal failure were treated. The regeneration system was applied in the treatment of Group 1 patients (n = 14), the traditional acetate hemodialysis procedure was used in Group 2 (n = 11). Hemodialysis with electrochemical regeneration of dialysis fluid removed creatinine and potassium ions from critically ill patients' blood as effectively as the traditional hemodialysis procedure. During electrochemical hemodialysis, middle-molecular toxins were removed better those with the traditional one, but urea and inorganic phosphorus were eliminated slowler. Electrochemical regeneration provided continuous purification of dialysis fluid. The regenerator block can be used many times. Sodium hypochlorite ensured self-sterilization of the system. The use of electrochemical regeneration does not require water purification, water communications and dialysis concentrate, which enables the detoxification procedure to be performed outside the specially equipped rooms.

[Experimental and clinical studies of methods for regenerating the dialysis solution]. / Eksperimental'noe i klinicheskoe izuchenie metodov regeneratsii dializiruiushchego rastvora.

The efficacy of artificial kidney apparatuses was assessed by using 5 different methods of regenerating the dialysis solution. In the series of model experiments the authors have studied the quality of the solution purification from urea, creatinine, uric acid, nonorganic phosphorus and potassium ions. Clinical trial of the regeneration systems was performed in patients with chronic renal failure on preparation for renal transplantation. The efficacy of the regeneration systems by elimination from the blood of metabolic products was not inferior to the standard hemodialysis system working in the discharge mode. The most promising method was that of electrochemical regeneration of the dialysis solution.

[Criteria for the choice of the extracorporeal detoxication method in patients with postoperative renal failure]. / Kriterii vybora metoda ékstrakorporal'noi detoksikatsii u bol'nykh s posleoperatsionnoi pochechnoi nedostatochnost'iu.

Criteria for the choice of a method for extracorporeal detoxication (acetate hemodialysis, intermittent or continuous hemofiltration or hemodiafiltration, or plasmapheresis) were defined on the basis of a detailed examination of cardiorespiratory function (central hemodynamics, oxygen-transporting function of the blood) in 88 patients with acute postoperative renal failure (PRF). Multiple organ failure occurred in 90% of the patients examined in the postoperative period. The severity of visceral and metabolic disorders was the principal criterion in the choice of extracorporeal detoxication method. Hemofiltration is the method of choice for the treatment of PRF combined with multiple organ disorders, primarily with acute circulatory, respiratory, and metabolic disorders, due to its stabilizing effect on the hemodynamics and a wide spectrum of pathologic substances removed by it. Acetate hemodialysis is indicated for patients with PRF and slow recovery of renal function only after elimination of grave hemodynamic and respiratory disorders, provided there are no general cerebral symptoms, because of its negative effect on the circulation and oxygen balance of the organism and central nervous system. Plasmapheresis is a pathogenetically valid method for the treatment of the initial stages of PRF in cases with massive intravascular hemolysis and sepsis, which may be combined with other methods for extracorporeal detoxication, if necessary.

[Hemodialysis with electrochemical regeneration of dialysis solution]. / Gemodializ s élektrokhimicheskoi regeneratsiei dializnogo rastvora.

The method of electrochemical regeneration of dialysis solution is virtually as effective as the traditional hemoperfusion system in removing creatinine and potassium ions from the body, but inferior to it as regards urea and inorganic phosphorus and superior in removal of medium-weight toxins. A more smooth reduction of urea level in the blood provides relatively stable hemodynamics in patients liable to hypotension. Electrochemical regeneration permits a continuous purification of dialysis solution, the regeneration block may be used many times, and sodium hypochlorite produced during electrolysis operation maintains the sterility of the system. Electrochemical regeneration does not require water purification systems, water communication, and dialysis concentrate, this permitting the performance of detoxication in rooms without special equipment.

[The electrical impedance indicator dilution method in studying the basic hemodynamic parameters during dialysis]. / Metod razvedeniia élektroimpedansnykh indikatorov v issledovanii osnovnykh parametrov gemodinamiki vo vremia dializa.

The procedure for measuring cardiac output and circulating blood volume is based on blood ability to modify its electrical conductance due to the amount of introduced ions (0.9% sodium chloride solution) or undissociated molecules (5% glucose solution). The cardiac output and circulating blood volume were calculated after measuring an area under the electrical impedance indicator dilution curve using the given formulas. With the described and thermodilution methods, the cardiac output was compared (r = 0.95). The correlation factor with the radioisotopic method in measuring the circulating blood volume was 0.88. Clinical investigations carried out in 47 patients on a programmed hemodialysis showed a significant decrease in cardiac output approximately by 700 ml/mi (7.9%) and circulating blood volume by an average of 900 ml (15.2%) by the end of a hemodialysis session, the rate of the circulating blood volume to body weight being also decreased. There was a predominant fluid "release" from the vascular bed.

[Study of parameters of central hemodynamics in patients during hemodialysis]. / Issledovanie parametrov tsentra'lnoi gemodinamiki u bo'lnykh vo vremia gemodializa.

The article discusses the results of study of the cardiac output (CO) and circulation blood volume (CBV) in patients at the beginning and end of hemodialysis. The dynamics of changes of these parameters during hemodialysis was studied in 31 patients (42 sessions). The CO and CBV reduced significantly. In a group of 10 patients who felt worse, the CO reduced by more than 30 per cent in 7, the CBV diminished by 25 and 30 per cent in 2, and CBV and CO reduced by more than 30 per cent in 1 patient in relation to the initial level. The CO and CBV were measured by means of the method of dilution of electroimpedance indicators.