Early postresuscitation centralization of the blood circulation

Experiments on cats were made to study the cardiac output and its main fractions supplying blood to the epi- and subdiaphragmal parts of the body during the postresuscitation period. The phenomenon of early postresuscitation centralization of circulation was established, correlating with the gravity of the sustained terminal state in the severity and duration.     

Effect of blood components on the stability of liposomes

The human blood plasma is studied for its effect on the outlet of different substances from lecithin liposomes. It is shown that in the presence of the whole blood the permeability of liposomal membrane for the low-molecular weight compounds increases sharply. Blood plasma proteins play a key role in this process but the influence of albumin, gamma-globulins, fibrinogen as well as of serum lipases is rather insignificant. An increase in the rate of outlet of substances in the presence of blood plasma depends on their molecular weight and may be explained by the formation of dynamic defects or pores of definite size in the liposomal membrane. The formation of these defects (pores) is supposed to proceed due to insertion of blood plasma proteins into the phospholipid matrix of liposomes.     

Humoral mechanisms in the regulation of work hyperthermia

Thermal reactions were investigated in rabbits: blood plasma donors running on treadmill to exhaustion and resting blood plasma recipients. Blood plasma was infused in the ear's vein and in the third brain ventricle cavity. Small elevation of body cork temperature (0.3-0.4 degree C) with the latent period 40-50 min was found on plasma infusion in the ear's vein of recipient. Plasma perfusion through the third brain ventricle of the recipient caused two peaks of nearly the same amplitude (0.8-1.0 degrees C) in body core temperature. The second peak, which was registered in 12-15 min after the perfusion began, was induced, as the authors suggest, by the accumulation of "work factor" of thermoregulation in donor's plasma during muscular work. Humoral regulation of working hyperthermia is discussed.     

Adrenocortical and thyroid systems of rats at the initial stage of nociceptive influence

There are two phases in the initial period of formation of adrenocortical response to sharp nociceptive influence. The first phase (within 10-15 sec.) involves emergency mobilization of "basal" reserves of hormone active substances. It is characterized by reduction of corticoliberine activity in hypothalamic and extrahypothalamic structures of the rat brain with a parallel increase of corticotrophin concentration in plasma, devastation of corticosteroid reserves in adrenal glands; a decrease in the level of corticosteroids in blood against the background of accumulating hormone in bodies-targets. In the second phace: the phase of hypercompensation, the progressive increase of credit of the substances under study was quite obvious. The authentic changes in a level of aldosterone in adrenal glands and blood took place only in 2.5 minutes after the stress. The nociceptive influence was also biphasic when acting upon the reorganization of thyroid status number. However, unlike the initial adrenocortical response to stress in the first phase of thyroid reaction, the elevation of plasma thyroxine and tri-iodothyronine level was obvious. At the second stage, selective decrease in concentration of thyroxine to normal amounts occurred.     

Humate-induced activation of human granulocytes

Naturally occurring humic substances are particular chemical compounds which are found in humus. They bind to carbohydrates, amino acids and steroids by means of hydrogen bonds, covalent bonds and epsilon donor-acceptor complexes. Three specimens of low-molecular humic substances were tested (two naturally occurring humates and one synthetically prepared humate). They were all capable of stimulating certain functions of human neutrophils (PMN), such as the respiratory burst which results in the production of toxic oxygen compounds. This PMN stimulation can be demonstrated with the help of chemiluminescence, as well as by cytochemistry and with the electron microscope. The main product of the humate-induced PMN response is H2O2. There was no activation of neutrophilic chemokinesis or chemotaxis. It is suggested that the low-molecular humic substances originating from decaying organic material contain chemical structures which can act as signals to change dormant PMN into activated cells.     

Effect of temporary hypovolemia on the early central pooling of the blood circulation following resuscitation and the survival of animals experiencing clinical death

The experiments were conducted on cats under pentobarbitone sodium anesthesia (40 mg/kg). The effect of 30-min hypovolemia (Wiggerse's model, 13.3 kPa or 100 mm Hg) on the cardiac output, its main fractions and the survival of animals recovered after clinical death (5 min) were studied. Hypovolemia was induced after cardiac contractions were recovered. In experimental (19 cats) and control (23 cats) studies clinical death was caused by arterial blood loss. The animals had been previously subject to hemorrhagic hypotension (according to Wiggerse, 6.7 kPa or 50 mm Hg, for 30 minutes). Temporary exclusion of part of blood volume from the circulation was found to abolish the phase of cardiac output increase in the postresuscitation period, attenuate the reaction of blood circulation centralization, improve the course of reparative processes and increase the survival of animals recovered after clinical death.     

The use of acridine orange for testing blood platelet integrity

Two processes are involved in the accumulation of acridine orange in human blood platelets. One follows a diffusion like kinetics and is independent of the ATP level whereas the second one can be completely abolished by ATP depletion. The acridine orange incorporation rate seems to be a suitable parameter for testing platelet integrity. It reflects very sensitively the influence of the preparation method as well as of anticoagulating substances used on the stability of platelet suspensions. The rates of acridine orange incorporation and of aggregation were measured in platelet-rich plasma and in saline suspended platelets after gel filtration, respectively, over a period of 120 min storage. Both rates are influenced to a different degree by anticoagulating agents such as citrate, heparin and EDTA. When contact with anticoagulating agents during platelet preparation is avoided, platelets show a constant acridine orange incorporation and aggregation during storage and the smallest morphological alteration.     

Correction of disorders of the system of blood aggregation regulation by ionol in the post-resuscitation period

In the experiments on white rats resuscitated after a 7-minute mechanical asphyxia, phase disorders in the indices of the system of regulation of aggregate state of the blood in postresuscitation period have been revealed. They appear in the shape of a syndrome of disseminated intravascular blood coagulation with the development of hypercoagulation phase by the 3rd hour. Prophylactic introduction of ionol in a dose of 100 mg/kg in 48, 24 and 1 hour before the experiment prevents the development and progressing of the above syndrome.     

The effect of low-intensity laser radiation on blood metabolic indices in the postresuscitation period]

The effect of He-Ne laser radiation (632.8 nm; 0.3 mW/cm parallel to oxygenation on metabolism indices of blood, taken in early postresuscitation period after discontinuation of hemorrhagic shock was studied in vitro. Compared to oxygenation alone, combined therapy resulted in more marked oxygen consumption of the blood, normalization of plasma antioxidant total activity, superoxydismutase erythrocyte catalase activity, the number of double connections in fatty acid chain of general lipids and membrane viscosity were elevated. Regular dependence of lipid peroxidation on a number of metabolic blood parameters is revealed.     

Vanadium accumulation and subcellular distribution in relation to vanadate induced cytotoxicity in vitro

A bovine kidney cell culture system was used to assess the relationship of vandium uptake and subcellular distribution to orthovanadate induced cytotoxicity. Twenty-four hr incubations with 20–1000 µM vanadium elicited 15–75% cytotoxicity. Concentration-related morphological changes from the control polygonal shape to the treated biopolar appearance were detected. Vanadium accumulated in cells via a multiphasic process; peak accumulation was achieved by 1 hr post-treatment and was followed by apparent decline, completed by 3 hr. A slower second phase of accumulation occured during the remainder of the 24 hr incubation period. A concentration-dependent accumulation resulted in a 50-fold increase in cellular vanadium content. Near maximum toxicity was achieved at a cellular vandium burden of approximately 5 nmoles/ 10⁶ cells; further accumulation (up to 35 nmoles/ 10⁶ cells) resulted in only a slight increase in the degree of toxicity. Subcellular distribution studies indicated 90% accumulation of vanadium in the soluble supernatant fraction (105,000xg supernatant) at varying stages of cytotoxicity. It was concluded that the multifaceted dependency of vanadium cytotoxicity on its cellular content may have resulted from a cellular balancing between proposed regulatory functions for vanadium and the interactions incurred with an excessive content.Abbreviations EDTA ethylenediaminetetraacetic acid - MDBK Madin Darby bovine kidney - MEM minimum essential medium - Na₃VO₄ sodium orthovanadate     

Fasting and refeeding in carp,Cyprinus carpio L.: the mobilization of reserves and plasma metabolite and hormone variations

Summary Carp, Cyprinus carpio, were subjected to a short term of fasting (2 months) and 12 days of refeeding. The early changes produced in plasma metabolites and hormones (insulin and glucagon) and their respective energy contribution in liver and muscle during fasting and refeeding was studied. Two phases of fasting were differentiated. The first phase (until day 8 of fasting) was characterized by a reduction in the hepatosomatic index mainly due to glycogen mobilization. A transitory increase in plasma glucose and lactate suggested an initial increase in energy demand. No changes were produced in the percentage of glycogen and protein in muscle, but musculosomatic index and the total body muscle protein decreased. Although the most depleted tissue in this phase was the liver, the loss of energy content of total muscle was higher. Stabilization of liver glycogen content, plasma glucose and lactate levels, decreased muscle protein levels and a reduction in the rate of body weight loss characterized the second phase (from day 8 of fasting). Protein content in whole muscle decreased by 22%, similar to the first phase. The energy expenditure of both liver and muscle was lower in this phase. Plasma insulin levels decreased two-fold and plasma glucagon three-fold in the first phase and remained low in the second phase of fasting. Twelve days of refeeding produced a greater increase in daily growth rate than in the control group and a recovery of plasma insulin, glucagon and glucose levels. Liver completely recovered. In contrast, musculosomatic index, protein and lipid content indicated that muscle did not completely recover from the 2 months of fasting, although and overshoot of muscle glycogen was observed.Abbreviations ANOVA analysis of variance - bw body weight - D1, D2, D5, D8, D19, D50 1, 2, 5, 8, 19 and 50 days of fasting, respectively - GSI gonadosomatic index - HSI hepatosomatic index - MSI musculosomatic index - P-DNA deoxyribonucleic acid phosphorus     

Quantifying patterns in the evolution of reproductive isolation

We present a likelihood-based statistical method for examining the pattern or rate of evolution of reproductive isolation. The method uses large empirical datasets to estimate, for a given clade, the average duration of two phases in the divergence of populations. The first phase is a lag phase and refers to the period during which lineages diverge but no detectable reproductive isolation evolves. The second is an accumulation phase, referring to the period during which the magnitude of reproductive isolation between diverging lineages increases. The pattern of evolution is inferred from the relative durations of these two phases. Results of analyses of postzygotic isolation data indicate significant differences among taxa in the pattern of evolution of postzygotic isolation that are consistent with predictions based on genetic differences among these groups. We also examine whether the evolution of postzygotic isolation is best explained by either of two models for the rate of accumulation: a linear model or a quadratic function as may be suggested by recent studies. Our analysis indicates that the appropriateness of either model varies among taxa.     

Change in concentration of cholesterol and lipoprotein fractions of rabbit blood serum in the dynamics of hypercholesterolemia]

Three quantitatively different periods have been detected as a result of 21-week monitoring of blood serum total cholesterol at hypercholesterolemia in rabbits. The first of them (4th week) ends by a relative decrease of cholesterol concentration: the second one (4th-13th weeks) is characterized by its sharp increase; in the third period (13th-21st weeks) the sterol accumulation slows down. Concentration variations of all main lipoprotein fractions are observed in each of the above periods. Their specific features enable us to suppose that in the first period the cholesterol transport system is activated which, probably, reflects the development of adaptation mechanisms of hypocholesterolemia. The second period can be considered as a transition stage from norm to pathology and is most likely, connected with atherogenesis induction. In the third period, in spite of relative stabilization of total cholesterol level clear signs of hyperbeta and hypoalpha dyslipoproteinemias are observed.     

Morphologic changes of the pancreas in hemorrhagic shock and the postresuscitation period

The canine pancreas (20) in the terminal period of hemorrhagic shock and postresuscitation period was studied histologically and electronmicroscopically. There were detected ultrastructural signs of the plasmatic membranes of pancreatocytes and membranes of secretory granules with "leakage" of pancreatic ferments in the interstitial tissue. The incretion of pancreatic ferments in the vascular bed is conditioned by the elevation of proteolytic activity of blood serum in hemorrhagic shock and postresuscitation period.     

Rapid blunting of sympathetic vasoconstriction in the human forearm at the onset of exercise.

The purpose of this study was to test the hypothesis that sympathetic vasoconstriction is rapidly blunted at the onset of forearm exercise. Nine healthy subjects performed 5 min of moderate dynamic forearm handgrip exercise during -60 mmHg lower body negative pressure (LBNP) vs. without (control). Beat-by-beat forearm blood flow (Doppler ultrasound), arterial blood pressure (finger photoplethysmograph), and heart rate were collected. LBNP elevated resting heart rate by approximately 45%. Mean arterial blood pressure was not significantly changed (P = 0.196), but diastolic blood pressure was elevated by approximately 10% and pulse pressure was reduced by approximately 20%. At rest, there was a 30% reduction in forearm vascular conductance (FVC) during LBNP (P = 0.004). The initial rapid increase in FVC with exercise onset reached a plateau between 10 and 20 s of 126.6 +/- 4.1 ml. min(-1). 100 mmHg(-1) in control vs. only 101.6 +/- 4.1 ml. min(-1). 100 mmHg(-1) in LBNP (main effect of condition, P = 0.003). This difference was quickly abolished during the second, slower phase of adaptation in forearm vascular tone to steady state. These data are consistent with a rapid onset of functional sympatholysis, in which local substances released with the onset of muscle contractions impair sympathetic neural vasoconstrictor effectiveness.     

Phenolic substances in the cell suspension culture ofCentaurium erythraea

The content of phenolic substances in the cell suspension culture ofCentaurium erythraea fluctuated during a 21-day-long subcultivation period in dependence on the growth phase. The total relative content of the phenolics reached its maximum at the time of transition to the exponential growth phase, similarly as the fraction of free phenolic acids, glycosides, and the fraction of phenolic acids released from the cells after alcaline hydrolysis. On the other hand, the content of phenolic acid esters decreased at this growth phase of the culture. Changes in the level of phenolic substances in the culture medium corresponded in their character to changes in the relative content of the phenolics in the cells.     

Inhibitors of reverse serotonin uptake and of specific imipramine binding in human blood plasma

Human blood plasma contains low-molecular substances that inhibit in a dose-dependent manner both high-affinity specific binding of imipramine and reverse serotonin uptake by platelets. Incubation of human blood plasma with alumina was made use of to extract and study these imipramine-like inhibitors. The extract obtained from human blood plasma inhibited imipramine binding and reverse uptake of serotonin with median inhibitory concentrations of 0.18 +/- 0.1 and 0.36 +/- 0.15 mg/ml, respectively. After gel chromatography on Biogel P-2 the elution profile of the extract showed 2 major peaks of reverse serotonin uptake and imipramine binding inhibition and 3 additional peaks of reverse serotonin uptake inhibition, which did not have any considerable effect on imipramine specific binding. It is assumed that endogenous inhibitors of imipramine binding and reverse serotonin uptake are involved in the development of affective disorders.     

Influence of the chronic gamma-irradiation at the low doses during the near ontogenesis periods on the oxidative processes in rodent organs

It is shown that the effect of the low intensity gamma-irradiation at the dose of 5.5 cGy during the 4 months including the antenatal period causes the most substantial changes of the peroxide content in the liver and in brain lipids and of TBA-reactive substances amount in organs and blood plasma of tundra vole F2 which are reproduced from parents during long-term inhabiting on the Ra-contaminated area in the Komi Republic. The consequences of the chronic gamma-irradiation at the doses of 4 cGy (the dose rate is 5 mR/h) and 31 cGy (the dose rate is 40 mR/h) are studied by the morphophysiological and by biochemical parameters in organs of mice CBA (males) within 3 months after exposure. The change of the scale of the interrelation between the liver and body masses and also between the sums of the more easily to the more poorly oxidizable fractions and the phosphatidyl choline to phosphatidyl ethanolamine ratio in the liver phospholipids in groups of the irradiated mice is found as compared with that in the control group. The absence of interrelation between the lipid peroxidation process intensity and the catalase activity in the murine liver and also between the disbalance of the biochemical functions and the dose rate and/or the dose of the gamma-irradiation is revealed. The analysis of the data obtained allow to conclude that the chronic gamma-radiation under low intensity has the systemic effect on the animal organism causing of its function on the other level.     

影响蝴蝶兰类原球茎耐脱水性的主要因素

为探讨蝴蝶兰(Phalaenopsis spp.)类原球茎(protocorm-like body,PLB)耐脱水性的主要影响因素,对PLB的平均粒重、含水率、脱水相对湿度、时间、温度、光周期与耐脱水性的关系进行了研究.结果表明,PLB的平均粒重与脱水后失水率、含水率、相对电导率、成活率呈显著或极显著相关.在较高湿度下...     

The prevention of the translocation of intestinal microflora after the rescue of an organism from a terminal state]

In experiments on guinea pigs, the animals were resuscitated from clinical death caused by the acute loss of blood and subsequently treated intragastrically with enterosorbents: activated carbon fibrous material, alone and in combination with polymyxin B, polyphepan (a lignin derivative), polymethyloxan hydrogel and the sorbent Enterocat. In the animals, not treated during the postresuscitation period, a high population level of enterobacteria and Gram-positive aerobic cocci was registered in the contents of the small and large intestines and their translocation to mesenteric lymph nodes, liver, spleen and blood was observed. The amount of lactobacilli in the small intestine was decreased. Enterosorbents were found to decrease a high population level of intestinal microflora, to prevent the translocation of Gram-positive aerobic cocci and to inhibit the penetration of enterobacteria through the enteric barrier in the postresuscitation period. Combined use of activated carbon fibrous material with polymyxin B proved to be most effective for the elimination of enterobacteria.