Biomedical subjects
Publications and source records attributed to D B Saprygin.
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Using a panel of monoclonal antibodies against human myoglobin (Mb), we have shown that the sensitivity of antigen-capture ELISA can be significantly increased by simultaneous immobilization of two cooperating capture monoclonal antibodies on a solid phase. This method ("triple-site ELISA") uses three monoclonal antibodies to different epitopes of the same antigen (two capture/one tracer) unlike the traditional double-site assay using one capture and one tracer monoclonal antibody. We developed double- and triple-site ELISA for Mb by varying the capture and tracer monoclonal antibodies. Triple-site assays showed 4-6-fold increase in sensitivity compared to the double-site assays. A model for this effect is suggested; according to the model, in triple-site ELISA, high-affinity cyclic configurations can be formed by an antigen, two capture monoclonal antibodies, and the surface of the solid phase.
In Wistar male rats, 1-h acute immobilization stress resulted in the increased plasma adrenalin, noradrenaline and dopamine in approximately 13, 8 and 23 times, respectively. Plasma PGF2 alpha increased in 3.5 times while PGE remained unchanged; this resulted in the decreased PGE/PGF2 alpha relation in 2.8 times. The PGI2/TXA2 relation also decreased in 1.5 times due to a more pronounced growth of TXA2 than that of PGI2. In rats adapted to the repeated stress (12 sessions), the plasma catecholamine level was higher than that in control but 2-3 fold lower than in unadapted rats after acute single stress. In this situation, PGE was increased by 70% as compared to the control. This is why PGE/PGF2 alpha relation was similar to the control whereas the level of PGF2 alpha increased. PGI2 increased by 53% and TXA2--in two times as compared to the control. In these rats, acute stress induced neither plasma catecholamine enhancement nor PGE/PGF2 alpha relation decrease in comparison with the initial levels; the TXA2 content was increased but it was by 33% less than that in unadapted rats exposed to such stress. One can suggest that the decreased activation of adrenergic system respondent to acute stress in unadapted rats is associated with the increase in plasma PGE and PGI2 which are known to limit the catecholamine release from adrenergic terminals and their harmful effects.
The article deals with a new method of treatment of the Wolff-Parkinson-White syndrome. The operation for epicardial destruction of Kent's bundle by pulsating current was developed by the authors. It is distinguished by its simplicity and the possibility to determine the efficacy of the procedures during the operation itself. The results of examination of 44 patients in the early postoperative period and in late-term periods after this operation are discussed. It was found that the electric factor does not cause structural changes of the underlying structures and does not affect the pumping function of the myocardium. The revealed changes were recorded by means of angiocardiography, coronarography, radionuclide ventriculography, and the enzyme spectrum.
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Blood thyroid hormones were measured before and after the rationed exercise test in 79 patients with angiographically verified diagnosis of coronary heart disease. A relationship was demonstrated between postexercise blood T3 variation and functional coronary circulation reserve. Hormonal baselines, and exercise-induced blood T4 changes were basically similar in patients with coronary disease of different severity. The results are suggestive of pathogenetic importance of thyroid function in these patients.
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During surgical correction of Fallot's tetrad the authors discovered the decrease of macroergic phosphate concentration and moderately marked signs of cardiomyocytic ultrastructural changes, such as mitochondrial injuries, decrease of glycogen levels, insignificant intracellular edema, no increase of membrane penetration. Changes of endothelial cells were absent. In children not over 1 year old under myocardial protection with hypothermic perfusion (at low volume rates) some decrease of macroergic phosphates occurred, as well as a moderate decrease of the mitochondrial index, glycogen content decrease, there was no intracellular edema. The discovered structural changes are minimal and reversible. A close correlation was found between the electron microscopic data and the character of myocardial energetic metabolism, the biochemical changes preceding the ultrastructural ones. Comparison of morpho- and biochemical changes in the myocardium of the majority of patients with impaired myocardial function confirmed the existence of a complex relationship between them.
A difference between baseline and final plasma hormonal (insulin, cortisol, somatotrophic hormone, triiodothyronine (T3) and thyronine (T4) levels, related to the pattern of response to physical stress, was demonstrated in 67 coronary patients with angiographically verified diagnosis. Post-exercise increase in these hormones was associated with their lowered baseline and elevated final blood levels, as compared to those patients who showed a decrease in hormonal levels in response to exercise, with the baselines exceeding final values.
The purpose of the study was to find out the character of the restructuring of enzymes and isoenzymes of creatine kinase (CK), lactate dehydrogenase (LDH) and glucose-6-phosphate-dehydrogenase (G 6 P-DH) in the myocardium, which occurs in patients with ischaemic heart disease (IHD), and to compare the activity of the aforementioned enzymes in the myocardium of patients with IHD, examined intra vitam, and in patients who died suddenly. An analysis was made of 11 samples obtained by myocardial biopsy from the left ventricle of patients with IHD and of 11 samples obtained at autopsy of patients with IHD who have died a sudden death. Serving as controls was bioptic material from the myocardium of 12 patients without IHD. In the myocardium of patients with IHD, examined intra vitam, a decrease in the activity of the mitochondrial isoenzyme CK (MiMi) and the isoenzyme LDH-1, and a considerable rise in the activity of G 6 P-DH were found. In patients with IHD, who have died suddenly, there was found only a decrease in isoenzyme LDH-1 activity and a reduced concentration of CK B-units. The experiments proved that the differences in the myocardial isoenzyme spectrum between the two groups of patients with IHD are not connected with the process of autolysis.
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Plasma insulin, cortisol and somatotropic hormone (STH) levels of coronary patients are related to the extent of atherosclerotic lesion of coronary arteries. The relationship between coronary atherosclerosis and hormonal activity becomes particularly evident through the pattern of hormonal response (a rise or a fall) to rationed exercise. An elevated insulin baseline and reduced postexercise levels are typical for coronary patients with only slightly narrowed (25% or less) coronary arteries. A tendency to higher baseline and postexercise plasma cortisol levels was noted in more severe coronary cases. Increased postexercise plasma STH levels were significantly more frequent in patients with less marked atherosclerotic lesions of coronary arteries.
The protective effects of cardioplegic solutions (CS) containing creatine phosphate (CP) were studied in a rat heart model of cardiopulmonary bypass and ischemic cardiac arrest. Isolated rat hearts were subjected to a 3-minute coronary infusion with CS containing CP in normothermic (37 degrees C) and hypothermic (4-6 degrees C) regimes. In the normothermia group, the postischemic functional recovery was 70-75% of the preischemic control value, while the cellular ATP and CP content was reduced but insignificantly. By contrast, in the hypothermia group, the postischemic functional recovery was markedly depressed, with the tissue high-energy phosphate content being appreciably lowered. The data obtained confirm high efficacy of CP-containing cardioplegic solutions administered under normothermia conditions.
Central hemodynamics, myocardial contractility and consumption of major energy substrates (lactate, glucose, non-esterified fatty acids, NEFA), as well as the total R wave amplitude from 12 standard leads were assessed in 20 patients with neurocirculatory dystonia (the control group) and 36 patients with chronic coronary disease. The changes in central hemodynamics and contractility were particularly marked in 12 of the more severe coronary cases with a raised total R wave amplitude. Myocardial energy supply in such patients is provided at the expense of NEFA. The mildest cases, whose total R wave amplitude was as low as that of the controls, showed unchanged left-ventricular contractility and normal hemodynamic response to the atrial stimulation test. Myocardial glucose and lactate extraction prevails in these patients. It is suggested that a relationship may exist between the pattern of myocardial energy metabolism and the amplitude of electrocardiographic R wave.
Sixty-seven patients with angiographically-confirmed coronary heart disease (CHD) were investigated. Three patterns of thyroid hormone (T3 and T4) response to exercise were identified: rising, falling and unchanged levels. Coronary patients with rising T3 levels in response to exercise typically showed smaller left-ventricular ejection values as compared to those patients whose T3 levels declined. Coronary patients with low baseline T3 tended to have elevated left-ventricular end diastolic pressure after exercise. The demonstrated changes in plasma thyroid hormone levels are related to the severity of coronary disease and can be "protective" or, on the contrary, aggravating. Because of smaller biologic activity, T4 does not basically affect clinical manifestations of CHD.
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