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Abstract: Analysis of planned endomyocardial biopsy specimens of heart allotransplants from 22 recipients revealed signs of humoral type rejection (slight, medium, and severe) presenting as fixation of IgG, IgM, and complement components (C3, C4d) in 61 of 63 sections. Permanent presence of rejection signs attests to rheumatoid course of this process.

Abstract Addition of splenocytokine therapy to combined therapy of peptic ulcer accelerated healing and prolonged remission.

The role of the metabolic status of the donor and the recipient in graft survival was studied with skin grafting between genetically different mouse strains (BALB/C, C3HA, DBA/2, and C57Bl/6). It was concluded that the donor must have a lower metabolic rate than the recipient when the involvement of structural elements of the graft is required for healing in skin plastic surgery. In contrast, when it is necessary to strongly biologically stimulate the reparative processes of the recipient, the donor must have a higher metabolic rate than the recipient.

Regeneration of deep burn wounds after transplantation of allogenic and autogenic fibroblast-like bone marrow mesenchymal stem cells and embryonic fibroblasts on burn surface was studied in 40 Wistar rats. Transplantation of allogenic and autogenic fibroblast-like bone marrow mesenchymal stem cells and transplantation of embryonic fibroblasts decreased cell infiltration of the wound and accelerated the formation of new vessels and granulation tissue in the wound in comparison with the control (burn wounds without cell transplantation). Regeneration processes were most active after transplantation of fibroblast-like bone marrow mesenchymal stem cells, in particular, autogenic cells, which was confirmed by more rapid decrease in burn surface area. Wound healing after transplantation of fibroblast-like bone marrow mesenchymal cells and embryonic fibroblasts was associated with long functioning of transplanted cells (as was shown by staining for β-galactosidase, the cells were transfected with an adenovirus vector carrying the marker gene). It is hypothesized that more rapid regeneration of burn wounds after transplantation of fibroblast-like bone marrow mesenchymal stem cells was due to low differentiation of these cells in comparison with embryonic fibroblasts.

We describe the possibility of obtaining cardiomyocyte-like cell cultures from rat, guinea pig, and human bone marrow stromal stem cells. The content of troponin I-positive cells attains 35-45% of the total number of cells in the cultures and persists at this level for up to 4 months under differentiation conditions. Spontaneous contractions of cardiomyocyte-like cells were observed after the formation of cell monolayer under differentiation conditions.

The possibility of using the atrial myocardium to control artificial ventricles is examined. Correlation was studied between the tension of the atrial wall and the tension and pressure in the ventricles during random variation of the cardiac rhythm was studied. Tension in the wall of the corresponding part of the heart was recorded by means of arch strain gauges and the intraventricular pressure by means of an electromanometer during catheterization of the chambers of the ventricles. The cardiac rhythm varied from 2.0 to 4.0 sec-1. Correlation was demonstrated in the atria between the tension and interspike interval (coefficient of correlation 0.62±0.05). Close correlation was detected between tension in the atrial wall and the intraventricular pressure. The coefficient of correlation in this case varied from 0.713±0.09 to 0.874±0.02 depending on the mean duration of the interspike interval. Information on atrial contractions can be used to control an artificial heart.

Conclusions: 1. Direct mechanical heart massage using the assistor can maintain in a stable manner for a prolonged period both the frequency and the constrictive force, and can also regulate the durations of the systolic and diastolic phases. 2. Direct mechanical heart massage is an effective method of restoring blood circulation when employed immediately after a sudden heart stoppage as well as after a lapse of 10 minutes. 3. The increased pressure in the left auricle during heart massage indicates the deficiency of the left ventricle and is apparently one of the basic causes that limit the duration of effective blood circulation.

Conclusion: We have considered the thermodynamic bases for the application of heat engines to drive the ventricles of artificial hearts in humans. An analysis of the Carnot, Brighton, Stirling, and Rankine cycles indicated that the Rankine cycle is preferable, specifically in its implementation in the steam piston engine. In this context it is essential that the optimal operating frequency for the motion of the steam engine's piston lies in the range of physiological frequencies for the contraction of the human heart, which allows the application of this engine for driving IAH ventricles without converting frequencies. We have further considered the physiological criteria for the application of heat engines as part of IAH, such as overall size, mass, efficiency, and provision of hemodynamics. It is pointed out that from the perspective of physiological compatibility the steam piston engine is optimal. With this in mind, for the implanting of a complete IAH it is necessary to supply separate drives for the ventricles by utilizing independent piston engines, as achieved in the “Mikron” project.

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Conclusions: 1. System design of an ABC device allows it to be compatible with various procedures of blood clearance and increases clinical efficacy, safety, and availability. The system approach to the ABC design implies computerization, automation, use of disposable blood-conducting elements, and electrochemical regeneration of dialyzate. 2. The multi-piece structure of ABC devices with universal perfusion unit and centralized control is invariant to the used procedures of blood clearance. It allows main perfusion unit to be supplemented with control and executive elements of artificial organs.

Strips of myocardium from the auricles of the hearts of patients with mitral stenosis (MS) and patients with cardiac septal defects (CSD) were treated with a solution of EDTA (3 mM) to increase the permeability of the cell membrane (scarification). In a 3 mM solution of ethylene-hexaminetetraacetic acid (EHTA), against the background of increased permeability of the membrane to the Ca-EHTA complex, whereby the Ca2+ concentration in the myofibrils can be regulated between 10-9 and 10-4 M, a mechanical response of the contractile proteins to a change in Ca2+ concentration was recorded. Despite identical threshold concentrations (5·10-8 M) and saturation concentrations (10-4 M) of Ca2+, strips from patients with MS were found to develop a maximal force per unit cross section of the strip only half as high as preparations from patients with CSD, which suggests a probable lesion of the contractile proteins in the hearts of patients with MS. The ratio between the amplitudes of contraction under conditions of complete calcium activation of the contractile proteins and a single isometric contraction for preparations obtained from patients with MS was 8–10 and from patients with CSD 4–5. It is suggested that this is the result of more profound changes in the apparatus of electromechanical coupling of the myocardium of patients with MS.

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The effect of a method of assisted circulation (counterpulsation) on the ultrastructure of the myocardium was studied in dogs. Electron microscopy revealed a sharp increase in the glycogen content in the heart muscle cells, mitochondria with a highly osmophilic, finely granular matrix, and high pinocytotic activity of the capillary endothelial cells. The results are evidence of metabolic changes in the myocardium and, in particular, that the myocardial muscle cells are functioning at a lower energy level. The changes discovered in the myocardial ultrastructure evidently account for the beneficial therapeutic effect of the method.

An artificial heart in which the output is automatically controlled by the venous return, when implanted into dogs in the orthotopic position was found to be highly sensitive to changes in the hemodynamic conditions (a decrease in the venous return, hypo- and hypervolemia, increased peripheral resistance) and prevented the development of critical situations. For 24 h the principal vital functions of the experimental animals were maintained.

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Cultures of human fetal pancreatic islet cells were transplanted into the liver of rats with diabetes induced by alloxan. This heterografting led to a prolonged fall of the blood sugar. Histological examination of the recipients'liver revealed groups of implanted islet cells.

Cultures of islets cells were obtained from the cadaveric pancreas of 16–25-week human fetuses. During culture two waves of mitotic activity were observed. An increase in the insulin concentration in the culture medium took place after a wave of mitotic activity.

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Experiments on rabbits showed that the period of organization of a venous thrombus and the first 24 h after thrombosis is characterized by a decrease in the number of platelets and in their coagulation, adhesive, and electrophoretic activity and by an increase in their aggregation and sedimentation rate. The changes in platelet function became less marked 2–5 days after thrombosis and were actually characteristic of hemorrhage.

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