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The aims of the present work were to perform a comparative study of the effects of delta sleep-inducing peptide and Deltaran on neurons in emotiogenic brain structures and to address the question of whether it is possible to prevent or decrease the negative influences of stress loads on the severity of subsequent cerebral ischemia in rats, using glycine with delta sleep-inducing peptide combined in the neuroprotective formulation Deltaran. The results showed that Deltaran and delta sleep-inducing peptide had largely the same actions on the nature of spike activity of neurons in the dorsal hippocampus, paraventricular nucleus of the hypothalamus, and ventral anterior nuclei of the thalamus, evoking activation of some of the neurons in these brain structures. The dorsal hippocampus was dominated by activation of spike activity in response to administration of delta sleep-inducing peptide; Deltaran produced activation mainly in the paraventricular nuclei of the hypothalamus. In all animals given Deltaran, the index of brain blood supply was significantly greater than in animals not given Deltaran. The survival rate of cerebral ischemia was 100% in animals given Deltaran. Death occurred in 38% of animals not given Deltaran.

The article reviews investigations performed in the Research Neurology Institute on blood flow biomechanics which resulted in discovery of a universal permanent theological blood factor--circulating cell-free plasmic DNA reducing hydrodynamic blood resistance in accordance with Toms' effect. In vitro and in vivo experiments were made with use of drag-reducing polymers for correction of circulation. Basic mechanisms were discovered by which cell-free DNA regulates normal and affected circulation. Clinico-experimental investigations demonstrated the role of imbalance between DNA concentration in blood plasma and length of its fragments caused by their change in cerebrovascular diseases, in disorder of circulation pattern. It was shown in animal experiments that it is possible to correct abnormal circulation characteristics in ischemic disorders of brain circulation by intravenous injections of high-molecular DNA solutions.

Adhesive properties of leucocytes were studied using an original technique based on the leukocyte adherence inhibition reaction and measuring the values of spontaneous adhesion index (SAI) and adhesion-strengthening effect (ASE) under the influence of autoserum. One hundred patients with multiple sclerosis (MS) and 53 controls were included in the study. Immunophenotyping of lymphocytes (LP) with monoclonal antibodies--markers CD3, CD4, CD8, CD16, CD20, CD25, HLA-DR and CD95--and determination of IgG, IgA, IgM and content of immune complexes were carried out in parallel. The increase of adhesion parameters (ASE and SAI) was found in MS. It was most significant in patients with primary progressive course and in disease exacerbation. The greatest changes of phenotypic LP content were associated with debut and exacerbation-remission periods. Significant positive correlations between higher SAI values and phenotypes CD20, CD95, HLA-DR and amount of natural killer cells were revealed in patients with MS in contrast to the negative correlations of SAI with CD3 and CD4 in the control group. A role of membrane and soluble forms of adhesion molecules in the initiation and progression of immunopathological process in MS is discussed.

Hemoglobin oxygen affinity within the estimated physiological range plays an adaptive antioxidant role during acute cerebral ischemia. This range depends on individual emotional resistance. Brain ischemia induced by common carotid artery occlusion in low resistant Wistar rats increased hemoglobin oxygen affinity by 12% during the acute period. Emotional stress also increased hemoglobin oxygen affinity and determined shifts in this parameter during the development of cerebral ischemia: moderate increase in hemoglobin oxygen affinity (<25%) was followed by further increase in this parameter, while more pronounced shift (>25%) resulted in a significant drop in this parameter due to hemoglobin deoxygenation. Adaptation to stress shifted the upper physiological limit for self-regulation of this process.

An aim of the present study was a comparative investigation of a delta-sleep inducing peptide and the drug deltaran on the neural activity of the brain structures involved in emotional processing. Another goal was to analyze the possibility to prevent negative effects of emotional stress on brain ischemia using, along with deltaran, glycine and a delta-sleep inducing peptide. Deltaran and the delta-sleep inducing peptide exert in general similar effect on the burst activity of neurons in the dorsal hippocampus, hypothalamic paraventricular nucleus and ventral anterior thalamic nucleus, inducing amplification of the majority of recorded units. The activation of neuronal activity was seen mostly after the delta-sleep inducing peptide microiontophoresis in the dorsal hippocampus and after the deltaran application in the hypothalamic paraventricular nuclei. The index characterizing blood supply was significantly higher in all rats receiving deltaran as compared to the controls. Animals receiving deltaran survived experimental brain ischemia in 100% cases versus 38% in those not exposed to this drug.

Intravenous injection ofpolyethylenoxide WSR-301 reducing hydrodynamic blood resistance (Toms effect) improves gas exchange in the lungs and halved lethality of the animals with cerebral ischemia. The aim of the study was to establish whether free plasma DNA influences blood gases and lethality of the animals with brain ischemia. Common carotid arteries were ligated for 15 min in intact stressed and tested in the open field Wistar male rats, then some of the rats received intravenous solution of homologous long-fragment DNA (20x10(-6) g/ml of blood). Cerebral circulation, acid-base equilibrium, paO2, paCO2, asymptotic blood viscosity, plasmic concentration and length of DNA fragments in plasma, lethality and neurological status of the survivors were studied. It was found that long fragments of rat DNA show hydrodynamic Toms effect. In normal passive rats sensitive to cerebral ischemia part of plasm DNA is fragmented, gas composition and blood viscosity of blood is worse (p < 0.05) than in active animals. There is a direct correlation between the level of long-fragment DNA in plasm and paO2 (r = 0.55) and inverse--with paCO2 (r = -0.84). Intravenous injection of long-fragment DNA improved the course and reduced lethality of brain ischemia 2-3-fold. Thus, qualitative and quantitative characteristics of plasma circulating DNA are responsible for differences in blood gases in rats differently tolerable to cerebral ischemia and can serve as one of the criteria of individual sensitivity to it being essential in pathogenesis of ischemic stroke.

Local cerebral blood flow in the left hemisphere decreased most significantly in low-resistant Wistar rats preexposed to emotional stress. Deltaran selectively increased blood flow in the left hemisphere and improved blood supply to neuronal activity unit of the brain in these animals. This drug prevented progressive decrease in local cerebral blood flow in both hemispheres during the acute stage of ischemia. The effect of Deltaran was related to modulation of collateral blood flow and adequate blood supply to neuronal activity unit in the brain tissue. Deltaran decreased the mortality rate (by 62%) and alleviated the symptoms of cerebral ischemia. The positive effect of Deltaran was more pronounced in the left hemisphere.

Deltaran decreased the amplitude of EEG slow waves and restored neuronal reactivity after carotid artery occlusion in Wistar rats sensitive to cerebral ischemia. Deltaran had no effect on local cerebral blood flow. This drug increased blood supply to a unit of neuronal activity in the brain of intact animals during the acute stage of cerebral ischemia, provided 100% survival rate of rats with cerebral ischemia, and prevented the development of neurological symptoms in survivors. Animal experiments proved the possibility of correcting cerebral ischemia with antistress drug Deltaran.

Adhesive blood properties have been studied in 100 MS patients with the help of the new method developed on the basis of the leucocyte adherence inhibition (LAI) test, which was based on the calculation of the ratio of adhesive cells to non-adhesive ones. The value obtained was called the Index of Spontaneous Adhesion (ISA), while the respective indicator reflecting the effect of adhesion strengthening under the influence of autoserum, being expressed by 30% and more, was named the Effect of the Adhesion Strengthening (ES-a). Blood samples of 54 donors and 31 patients with other neurological diseases were used as controls. Statistically significant increase of ISA values of MS patients was detected as compared to the group of donors. The highest indices of ISA and ES-a were found in the primarily progressive course and at the stage of MS exacerbation in the remitting course. Correlation between levels of adhesion and clinical features as well as parameters of clinical and humoral immunity are described. A role of membrane and soluble forms of adhesion molecules in initiation and progression of the immunologic process in MS is discussed.

The ratio of low-activity and high-activity rats differed in autumn, winter, and spring litters. Initially more intensive cerebral blood flow in low-active rats and its more pronounced decrease after common carotid artery occlusion determined their higher sensitivity to cerebral ischemia (compared to high-activity animals). After 18-h immobilization stress cerebral blood flow decreased by 10-15%, which abolished the difference in the individual resistance to cerebral ischemia. Independently on emotional resistance, cerebral ischemia was not accompanied by the development of collateral blood flow in the acute period and caused death of 90% rats.

The influence of laser therapy on the course of Parkinson's disease (PD) was studied in 70 patients. This influence appeared adaptogenic both in the group with elevated and low MAO B and Cu/Zn SOD activity. Laser therapy resulted in reduction of neurological deficit, normalization of the activity of MAO B, Cu/Zn-SOD and immune indices. There was a correlation between humoral immunity and activity of the antioxidant enzymes (SOD, catalase). This justifies pathogenetically the use of laser therapy in PD.

DNA of blood plasma is the factor which corrects hydrodynamic resistance (HR) of blood flow and provides Thomes' effect. As comparative hydrodynamic effectiveness of various plasma DNA forms (nucleoprotein, thread and denaturated DNA isolated standardly from human leukocytes) remains unknown, the in vitro test identified HR of the flow of the above DNA forms weak solutions--10(-6) to 10(-5) g/ml--necessary for achievement of Thomes' effect in strictly similar hydrodynamic conditions warranting a turbulent flow (Re 8000). Thomes' effect was confirmed in blood samples in its absence in low-molecular solutions (glycerine) with the same asymptotic viscosity. It was found that HR of the flow of synthetic polymer solutions producing Thomes' effect depends on its initial concentrations. Hydrodynamic effectiveness in the used solutions of the nucleoprotein and DNA was high being comparable to that of the synthetic polymer widely used in production for obtaining Thomes' effect.

The paper describes differences of hypoxic and circulatory hypoxias (i.e. brain ischemia) which cause decreases not only in the supply of O2, but in the delivery of glucose and other oxidation substrates and in venous return, which is attended by the accumulation of metabolic products in the brain tissue. It also considers the mechanisms of primary and secondary brain ischemia occurring with decreased cerebral circulation due to breakdown of cerebral blood flow autoregulation at its lower and upper borders to develop cytotoxic or vasogeneous brain tissue edema with possible compression of the microcirculatory bed in the latter case. Emphasis is laid on the significance of autoimmune reactions occurring with the impaired blood-brain barrier due to different types of cerebral circulatory disorders, which gives an insight into the cause of progressive damage to the brain in some cases despite its single damage. The paper outlines current therapies for brain ischemia, including those that exert effects on metabolic disturbances and neurosurgical reparative operations. In conclusion, the paper considers a new nontraditional way of increasing collateral CBF by decreasing blood flow pseudoturbulence with special high molecular-weight linear polymer solutions by the Thoms-effect method (1948). The prospects for using this approach in patients with brain ischemia are substantiated by a number of the established facts: 1) the above patients have higher hemodynamic blood flow resistance which may be corrected by adding a polymer solution into the sample in in vitro tests; 2) there was an inverse relationship of the intrinsic plasma concentrations of high molecular-weight fragments of DNA and hemodynamic resistance to the changes in plasma DNA properties in stroke patients.

The reactivity to the myelin basic protein, brain gangliosides purified derivative and also the influence of the serum on the cells adherence were determined by micromodification of the leukocyte adherence inhibition (LAI) test. 46 multiple sclerosis patients, 21 patients with hereditary disease and 41 donors were examined. The cellular sensitization to the myelin basic protein and brain gangliosides was revealed in 57% of the multiple sclerosis patients. The leukocyte adherence was increase in 53.5% patients when autologous serum was added. The adherence factor was most often found (90% case) in patients with severe neurological deficit. It is suggested that this factor is a connected t the increased levels of circulating adhesion molecules in multiple sclerosis patients.

Lipid peroxidation was studied in the brain of Mongolian gerbils under conditions of complete ischemia followed by recirculation in the left hemisphere without recirculation in the right hemisphere. Thiobarbituric acid reactive products and the intensity of Fe2+-induced chemiluminescence were determined. The content of lipid peroxidation products in the brain tissue was increased not only under conditions of recirculation, but also at the ischemia stage during the limited access of oxygen. Thus, the destructive effect of free radicals may occur even during the early stage of ischemic injury of the brain.

Flow structure and wall shear stress and the changes in these parameters induced by the administration of a drag-reducing polymer polyethylene oxide WSR-301 at a concentration of 10(-5) g/ml were studied in a glass tube with a T-junction by the laser Doppler anemometry technique. The pattern of wall shear stresses is in a good agreement with the data, obtained for rabbits in [1]. For tubes with rigid walls, the location of plaques corresponds to regions of a high wall shear stress.

Open field tests were made on 489 white male rats to distinguish subgroups by baseline higher nervous activity (HNA) to study the effects of cerebrolysin (EBEVE, Austria) on relationships between neuronal activity and cerebral blood supply in normal cerebral circulation (CC) and in acute brain ischemia. Local CC and EEG were measured by laser doppler flowmeter and read from the same point gauge. CC/EEG index was calculated. Cerebrolysin was injected i.p. in a dose 0.3 ml/100 g body mass. Brain ischemia was provoked by occlusion of the common carotid arteries. Neurological symptoms were estimated according to the McGrow scale. Also, 24-h lethality was registered. It was confirmed that cerebrolysin, as an active nootrop, enhances EEG. This effect takes place both in intact and brain ischemia rats. It was also found that cerebrolysin has different effectiveness dependent on the animal's behavior in the open field test, that blood supply to the brain does not increase in cerebrolysin-activated HNA. In stable circulation, this was compensated due to cerebral metabolic reserve, but in intensive EEG activation, recorded by CC/EEG index, cerebrolysin reduces cerebral blood supply aggravating acute brain ischemia.

To reveal the hemodynamic effect of plasma DNA, the authors measured the concentrations of plasma DNA, the length of its molecular fragments, and hemodynamic resistance/Toms effect. The Toms effect was detected in all blood samples from 10 healthy donors and 39 patients without acute stroke caused by atherosclerosis of the head great arteries with and without arterial hypertension. There was a clear inverse relationships between the plasma concentrations of DNA which had only long-molecular fragments in healthy persons and the hemodynamic resistance of its blood flow samples. The patient blood plasma had significant increased DNA concentrations but their molecular fragments were long and short. Inverse relationships between the plasma DNA concentration and the hemodynamic resistance of the patients' blood flow samples had a less correlation coefficient due to the high proportion of short DNA molecular fragments. The Toms effect was shown in the DNA solution prepared only from human funic blood where the DNA molecular fragments were long. The Toms effect was absent in the solutions prepared from the commercial cattle or salmon sperm DNA which contained shorter DNA molecular fragments. It is concluded that plasma DNA has a hemodynamic effect and the origin of long-molecular fragments of DNA which is typical for healthy young persons and short DNA molecular fragments that additionally appear in patients with vascular disorders is different.

The data about the role of blood flow in atherosclerosis development were examined. The aim of the study was determination of hydrodynamic blood resistance and Toms effect in patients with ischemic disorders of cerebral circulation in different periods of the disease. 45 patients with atherosclerotic damages of major arteries of head were observed. Such damages were combined with arterial hypertension in 32 individuals. The value of hematocrit, asymptotic viscosity, hydrodynamic resistance and Toms' effect were determined in blood as well as levels of cholesterol, beta-lipoproteins and platelets. The presence of Toms' effect was found in blood samples of both patients and controls. There was a significant increase of hydrodynamic blood resistance in all the patients as compared to control group. The patients with ischemic disorders of cerebral circulation were compensated by their own blood factor in less degree in acutest and acute periods than later. Low values of Toms' effect in separate patients were prognostic sings for good restoration of neurologic functions; higher values were observed in patients with arterial hypertension. The conclusion was made that hemodynamic properties of blood flow may be considered as predictors of the severity of the course of cerebral circulation disorders.

The contribution of Laboratory of Nervous System's Experimental Pathology (Institute of Neurology of Russian Academy of Medical Sciences) to cerebrovascular circulation investigations is described. The following questions were considered: cerebral circulation in cerebrovascular disturbances, collateral circulation in the "turned off" state of different brain arteries, and immunological brain alterations as the result of brain organic diseases. Results of the investigation of the damaging effect of acute increase in arterial pressure as well as individual sensitivity to brain ischemia and to drug administration were presented. The particular importance of researches of blood circulation biomechanics as well as of factors of its normalization were also emphasized.

In anesthetised Wistar adult male rats, a model of circulatory brain ischemia was created. A behavioural difference as well as a difference in normal focal cerebral blood flow (CBF), were revealed between rats resistant against and predisposed to emotional stress. The mortality level was 10% in former rats and 27% in latter ones.

The changes occurring in the immunity of 118 patients with focal brain injuries verified at surgery and during computed tomography were studied in relation to hemispheric lateralization. Patients with left-sided brain injuries showed more severe abnormalities of immunity and had a considerable lot of pyoinflammatory complications, including extracerebral ones. In patients with right-sided brain injuries, compensation of the changed immune responses occurred more rapidly, but intracranial pyoinflammatory complications took place more frequently. The magnitude and changes in immunity were found to depend upon the hemispheric lateralization of focal brain injuries, which characterizes that the brain regions play unequal role in the formation of an immune response. Differences become significant at week 3 at the peak of secondary immunodeficiency.

The experiments on adult rabbits have demonstrated that high-cholesterol diet given to the animals for 3 months causes a severe hypercholesterolemia and disseminated aortic lesion due to the formation of numerous fatty streaks and plaques of atherosclerotic genesis. The simultaneous intravenous injection of a special linear high molecular-weight polymer solution, which reduces hydrodynamic resistance once a week leads to a significantly less atherogenesis in the same hypercholesterolemia. The highest effect was observed in the descending portions of the aorta and just after its bifurcation, i.e. in the areas of the least unsteady blood flow.

In three series of experiments on 16 randomly inbred adult male rats, specific features of morphological changes in the brain were studied 3 days following the tests of animals for high- or low-resistance to hypoxic hypoxia (HH) during hypobaric HH (Series I), normobaric HH (Series II), and hypobaric normoxia (Series III). The conventional testing was found to result in changes in the rat brain, which were caused both by HH and decompression. The more sparing procedure is testing animal during normobaric HH which eliminates the impact of decompression whose damaging action was pronounced in hypobaric normoxia. Thus, the sensitivity of rats to HH should be detected, by using the least brain-traumatizing modified procedure--normobaric HH.

The increase of blood cell auto- and interactivation and the decrease of aspirin antiaggregant effect were demonstrated under hemodynamic conditions of a stenotic zone in a model maximally approached to the real blood circulation. The lowering of platelet activation, of the release of active agents from platelets, and of platelet-leukocyte interactivation was attained under the conditions of the flow modified by the drag-reducing polymer solution. The recovery of aspirin antiaggregant activity and aspirin-induced reduction of the total platelet release of platelet- and leukocyte-activating agents were demonstrated under the influence of the polymer.

In order to determine the patient blood flow hydrodynamic properties in terms of the Toms-effect, the time blood flow was measured in special apparatus twice: (1) before and (2) after addition of poly(ethylene oxide) WSR-301 (Union Carbide, USA) in concentration of 2 x 10(6) g/ml of blood sample (50 ml with 500 units of heparin) taken from 26 patients with acute ischaemic stroke, 8 patients with vascular encephalopathy after stroke, 5 patients with vascular encephalopathy following atherosclerosis with or without arterial hypertension. The blood samples taken from 8 healthy persons formed the control group. Haematocrit (HCT) and asymptotic blood viscosity were studied also. It was established that hydrodynamic blood flow resistance (HBFR) did not depend on HCT and viscosity, but was significantly higher in all patient groups than in normal persons (p less than 0.05). Addition of polymer solution decreased HBFR of patient blood more intensively that in the control group. We believe that it indicates an insufficiency of an unidentified factor in native human blood.

The search for antiaggregatory compounds is undertaken, as a rule, under in vitro conditions which do not reflect the dynamics of the real process. The present work deals with study of the peculiarities of the development of the collagen induced microembolic syndrome and the effect produced on it by hydrodynamic resistance reducing polymers under conditions modelling real circulation. The authors show the formation of a developed microembolic syndrome under the effect of collagen with accumulation of vasoconstrictors in the environment and increase of red cell hemolysis. Reduction of blood flow turbulence by the addition of solutions of neutral high-molecular linear polymers revealed the inhibiting effect of these polymers on the development of intracellular aggregate formation and concomitant red cell microhemolysis, which was attended by sharp reduction of thromboxane A2 production in the experiment. The authors show the significance of hemodynamic conditions in the development of the microembolic syndrome and the possibility of preventing it under conditions of modification of the blood flow with polymers, which may be of high prophylactic importance.

It was demonstrated in rabbit experiments that in decrease of the hematocrit value by more than 10% the increase of arterial pressure induced by intravenous noradrenaline injection and its additional rise are significantly higher than in the controls. In spite of that, the breakthrough of autoregulation of local cerebral blood flow occurred much less frequently, was less pronounced, and attended by significantly less damage to the permeability of the blood-brain barrier to labelled blood albumin. This phenomenon can be explained by the fact that in reduced blood viscosity the pseudoturbulence of its flow, and the hydrodynamic resistance of blood increase due to which it reaches the microcirculatory bed at a lesser pressure than in the controls. The results of the study substantiate the expediency of blood-letting as a therapeutic measure for patients with hypertensive disease, in hypertensive crises also.

Overall 393 patients with different types of closed brain injury (CBI) were examined for the immunological blood parameters in the acute and late periods. The decrease of immunological defence of the organism and possibilities of inflammatory complications in the lungs were established. CBI was found to run a progredient course in 27.7% of patients who suffered brain concussions++, in 54.5% of cases after repeated mild CBI, and in 73.7% of patients after severe CBI and CBI of medium gravity. Some immunological criteria and an approximate scale of a probability of the progredient course of CBI were proposed.

The dynamics of changes of immunological parameters were studied in 383 patients with various types of craniocerebral trauma (CCT) in the acute and late-term periods. It was established that the immunological processes in CCT occur in stages. The phases can be distinguished in the acute period: stress reaction (1st-3rd day), phase of maximal changes (7th-21st day), and normalization of the immunological parameters (30th-45th day). A wave of recurrent aggravation of the immunological parameters occurs on the 8th-14th day after CCT in an organism sensitized to the brain antigen, which is linked with autoaggressive damage to the brain.

Acute experiments on isolated segments of carotid arteries of cats and on human middle cerebral arteries have demonstrated the narrowing effect (15-18%) during the perfusion with solution of polymer with extraordinary lengthy (WSR-301, USA) in concentration of 2.10(-6) g/ml. Effects were doze- and endothelial dependent. It has been established that arteries responded to minor changes in experiments with the increase of the fluid flow (from 15 to 40 ml/min). It may be concluded that the diminishing of arteries reaction in the presence of polymer solution depended on the drug reduction polymer influence on shear stress, and changing of angio-hemo relationships.

Experiments were conducted on rats with temporary (10-min) clamping of the thoracic vascular bundle and subsequent resuscitation to study the permeability of the blood-brain barrier (BBB) to plasma albumins and globulins and to blood plasma immunoglobulins in different stages of the postresuscitation period. Mild increase of BBB permeability was detected 3 minutes after the beginning of recirculation. Permeability increased markedly in 24 hours and continued growing by the 72nd hour. At a 1-3-hour interval in recirculation the BBB was closed. The obtained results disclose the mechanisms of the development of autoimmune cerebral disorders in an organism that experienced cardiac arrest and resuscitation.

Hematoencephalic barrier (HEB) permeability was studied in 78 rabbits. HEB permeability for 32P was examined in animals with phlegmons on the posterior paws and on the maxillofacial area; HEB permeability was sharply increased in the latter group animals. Central cholinolytics and antioxidants were used to normalize this parameter in the rabbits with maxillofacial phlegmons.

Sera from patients with lateral amyotrophic sclerosis (LAS) were discovered to produce a cytotoxic effect one hour after their intracerebral administration to experimental animals. Coons' test using serum against human gammaglobulins was used to detect their selective binding to separate cells of nervous tissue culture. The data obtained point out that LAS patients' serum contains different anticerebral antibodies whose presence may account for the cytotoxic effect of these sera on the ultrastructure of experimental animals' nervous tissue.

Clinical and immunological studies were performed in 45 patients with HCD. A group of patients was investigated by conventional immunology tests. spontaneous and active rosette formation, theophylline test, immunofluorescent B-lymphocyte investigation, IgA, IgM, IgG and circulating immune complexes (IC) levels measurement. Monoclonal antibodies were used to count T- and B-lymphocytes, T-helpers and T-suppressors in another group. [3H]-spiroperidol binding to blood lymphocytes was studied in 28 patients. Immune indices were found to be related to the disease duration, degree of visceral deterioration and the duration of Cu-depleting drugs administration. After a prolonged treatment with D-Penicillamin or Cuprenil immune indices returned to normal levels while the count of theophylline-sensitive lymphocytes remained unchanged. The mechanisms of metabolic and immune interrelations in HCD are discussed.

The dynamics of acute phase proteins (fibrinogen, alpha 1-antitrypsin, alpha 2-macroglobulin) and immunoglobulin G in the blood serum was studied and compared in 40 patients with ischemic brain stroke to the localization and distribution of those proteins in the cerebral tissue (4 sectional cases). To measure proteins in the blood and cerebral tissue, use was made of laser nephelometry, radial immunodiffusion and chemical methods with the employment of monoclonal antibodies to the proteins under study. It has been demonstrated that acute phase proteins detected in the blood in the acute period penetrate into the brain, being demonstrable there for a longer time than in the blood, thus attesting to the increased permeability of the blood-brain barrier and low intensity of their tissue metabolism in the area of foci of vascular brain impairment.

The ultrastructure of the blood-brain barrier (BBB) was studied in different periods after the effect of acute hypoxic hypoxia. Local changes in the BBB ultrastructure indicating increased transport of blood plasma through certain areas of the vascular wall were seen already 24 hours after the hypoxia session. Four days later these changes were more marked and more diffuse. In 7 days the ultrastructure of the vessels and the surrounding brain tissue showed more significant changes. In later periods a tendency towards restoration of the BBB ultrastructure was revealed, which was also irregular in its course. The greater or lesser vulnerability of the different regions of the brain vessels may be determined both by the uneven decrease of their tonus and by the possible differences in the metabolic changes in the different areas of the brain vascular system under such conditions.

The extravasation of serum albumin and immunoglobulin G (IgG) was assayed by electroimmunoassay in cerebral cortex homogenates of rats subjected to stab wound injury either 2 weeks after immunisation to brain antigens or without prior immunisation. The amount of IgG in the brain was significantly higher in immunised than in non-immunised rats 3 and 24 h after injury. A significantly enhanced extravasation of albumin in immunised rats was found only after 24 h. It is concluded that immunisation to brain antigens enhances the vulnerability of the blood-brain barrier in rats subjected to stab wound injury.

Changes in immunological responsiveness, including humoral and cellular immunity, spontaneous rosette formation of neutrophils and their phagocytic activity were investigated in 100 patients with acute disorder of the cerebral circulation, in 25 clinically healthy individuals and in 20 patients with essential hypertension. The findings made it possible to confirm the presence of immunological changes following cerebral strokes as well as their influence on the course and outcome of acute impairments of the cerebral circulation.

The effect of different dexamethasone doses on the development of edema of the brain in its injury was studied on 79 rabbits, controls and those sensitized with the brain antigen. The local cerebral circulation and the total tissue fluid in the perifocal region of the injured grey and white matter of the rabbit's cerebral hemispheres were studied; EEG was recorded and ultrastructural study of the nervous tissue in the zone of the trauma at the level of the ultrastructures was conducted. The examination showed that dexamethasone had a favourable therapeutic effect on the course of the brain trauma in the early periods after it was inflicted; the agent reduced edema of the brain tissue, which was especially manifest in animals with altered immunological reactivity of the organism. The best effect in these animals was caused by large doses of dexamethasone.