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Biomedical subjects

E B Sirovskiĭ

Publications and source records attributed to E B Sirovskiĭ.

At least 19 recordsLinked to original sources
PubMed1992

[Intracranial distension in neurosurgical pathology].

In contrast to the classic research into the problem of intracranial pressure based on the assumption that pressure in the cranial cavity is distributed uniformly, the initial methodological principle of the present work rests on the concept of the nonuniform distribution of pressure in the intracranial system both in health and disease. Comparative dynamic measurements of cerebrospinal fluid and brain tissue pressures were carried out in the early postoperative period to reveal absolute magnitudes of pressures and their correlations. Under examination were 166 neurosurgical patients with different levels of brain injury. The magnitude of cerebrospinal fluid pressure was demonstrated to depend on the level of brain injury. In the groups examined, intracerebral pressure of interstitial fluid in "normal" brain tissue was approximately the same (from -3 to +2 mm Hg). In brain edema, that pressure increased, sometimes to a considerable measure (up to 50 mm Hg). Neurosurgical pathology was shown to be characterized by nonuniform distribution of pressure in the main intracranial media: brain tissue and cerebrospinal fluid, which disturbs the physiological ratio of these pressures. It should be mentioned that some of the structures are under normal pressure whereas the other ones under elevated or lowered as compared to the physiological norm. Such a state can be correctly characterized by the term "intracranial distension" bearing in mind nonuniformity of tension in the intracranial system, a possible one-staged coexistence in the crane of the areas with elevated, normal and lowered pressures.

Brain Neoplasms↗
PubMed1991

[Mechanisms of development of brain edema in neurosurgical pathology].

As many as 120 neurosurgical patients were examined after the excision of hemispheric gliomas, basal and subtentorial tumors. Based on an the computer-aided analysis biochemical and clinical data, attempts have been made to unify the mechanisms responsible for brain edema development in patients with neurosurgical pathology. In the early postoperative period, brain edema occurs in 95% of neurosurgical patients. Edema development, spreading and intensity depend on the site and nature of the primary pathological focus as well as on traumatism of surgical interventions. It is proved that edema is an original, biologically expedient brain response to its injury. This response manifests in hyperhydration of all tissues, with the maximum intensity being concentrated in the focus of injury. Specific (neurogenic neurohumoral) and nonspecific (biochemical, autoimmune, mechanical, and so forth) factors of brain edema development may be distinguished. The differences in the neurogenic and neurohumoral mechanisms by which brain edema develops may be accounted for by the topography of the focus of injury. The closer the pathological focus is to the stem and diencephalic structures, the more remarkable the action of neurogenous and neurohumoral factors and the more distinct the tendency toward edema generalization are. At the diencephalic level of injury, damaged are the structures responsible for central regulation of metabolism and trophicity of nerve cells. The neurogenously precipitated diffuse impairment of permeability of the cells entails their hyperhydration, which marks cellular (cytotoxic) edema. The subtentorial process that affects the vasomotor centre of the stem triggers the neurogenic diffuse alterations in the vascular tone, manifesting in an increase of permeability for water and plasma proteins which is characteristic of vasogenic edema.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Water↗
PubMed1983

[Clinical aspects, EEG and biophysical and biochemical parameters of the intracranial system in large fractionated-dose irradiation].

Seven patients operated on for intracerebral tumors received a course of large fractionating irradiation during which the patients' clinical status, changes of the ventricular CSF pressure, intracerebral pressure of the interstitial liquid, biochemical parameters of the blood and CSF and the EEG summary rate were assessed over time. The patients' reaction was characterized by a moderately expressed change of the above parameters in response to irradiation which returned to normal within 12 hrs. following large fractionating irradiation.

Biophysical Phenomena↗
PubMed1981

[Intracerebral pressure and the EEG following graded changes in cerebrospinal fluid volume].

The effect of graded change of the CSF amount on the clinical status, intracerebral pressure and brain bioelectrical activity was studied in 31 patients operated on for brain tumors of various sites. Normally, the graded change in the CSF amount made with an object of examining the biophysical characteristics of the intracranial system did not produce the impairment of the patients status. Discomfort sensation that occurred in rare cases was not a consequence of either hypo- or hypertension as such but of the absence of CNS ability to adapt rapidly to the changes of the pressure in the cranium. The graded change in the CSF amount and thus in the CSF pressure caused minimum transitory changes in the intracerebral pressure of interstitial liquid and in brain bioelectrical activity. The data obtained indicate the feasibility of studying the biophysic characteristics of the intracranial system by means of graded changes of the CSF amount in neurosurgical patients undergoing acute postoperative period.

Biophysical Phenomena↗
PubMed1979

[Results of mass spectrometry studies of oxygen and carbon dioxide tension and blood flow in the brain tissue of neurosurgical patients].

The results of composite appraisal of the tissue tension of oxygen, carbon dioxide, and regional blood flow in the brain of 21 patients during the early period after neurosurgical operations are discussed. The dynamics of the efficacy indices of the cerebral circulation and gas exchange were studied during intensive therapy of postoperative pathological conditions. It was established that the use of some of the components of intensive therapy in severe intracranial pathological conditions is attended with changes in cerebral gas homeostasis.

Adolescent↗
PubMedDate not supplied

[Comparative study of intracerebral and cerebrospinal fluid pressure in neurosurgical clinical practice].

Comparative measurements of cerebrospinal fluid pressure(CSPF), total local intrabrain pressure (IBP) and interstitial fluid pressure(ISFP) have been made in 32 neurosurgical patients in the postoperative period. The obtained data prove that IBP is almost twice higher than ISFP and 1.5 times higher than CSFP. The data of this study show that no direct hydrostatic relation exists between the cerebrospinal fluid and the interstitial fluid. The reasons of "negative" values of ISFP are also discussed. The intracranial pressure is to be considred as a combination of selective mechanical pressures of the main intracranial components. Therefore a more precise term "intracranial pressures" is suggested.

Brain↗
PubMedDate not supplied

[The mechanism of the development of spontaneous fluctuations in the cerebrospinal fluid pressure ("plateau" and B waves)].

The peculiarities of the development of spontaneous fluctuations of the c.s.f. pressure (CSFP) (B- and plato-waves) in the early postoperative period in 169 neurosurgical patients were studied according to the location of the pathological process and the severity of the clinical condition. The dependence between the CSPF spontaneous fluctuations, the changes of intracerebral pressure, and the dynamics of bioelectrical activity of the brain was studied. The development of spontaneous wave CSFP fluctuations was found to be dependent on the location of the tumor and the severity of the clinical condition. These fluctuations occurred most frequently in patients who were in a critical state (12-8 marks on Glasgow's scale) with the process located in the diencephalo-stem brain areas. A hypothesis is suggested, according to which the cause of the wave CSFP fluctuations of the B-wave type is connected with the change of the vasomotor center to the cyclic regimen of work: the neurogenic change of the vascular tonus, causing in succession constriction and dilatation of the vessels, leads to rhythmic CSFP oscillations. CSFP plato-waves occur in cases in which the constriction phase fails to appear after the dilatation phase, i.e., the tonic pressor effect of the vasomotor center does not occur, which may be due to its exhaustion. In death of the brain and in terminal states the vasomotor center loses the ability to cause neurogenic regulation of the vascular tonus, to provide the pressor effect in particular, which leads to the disappearance of spontaneous CSFP fluctuations.

Brain Death↗
PubMedDate not supplied

[Brain edema as a cause of critical states in neurosurgical patients].

The results of the studies in 120 patients after resection of tumours located in cranial fossa (40 cases), basal-diencephalic area (45 cases), hemispheres (35 cases) have shown the role of brain edema in the onset of critical conditions after neurosurgery (with consideration of a new concept concerning the mechanisms of brain edema development). It has been demonstrated that brain edema at its early stages is a biologically expedient adaptation response to any damage and is manifested in hyperhydration of all the tissues, most marked in the affected focus. Specific (neurogenic, neurohumoral) and non-specific (biochemical, autoimmune, mechanical, etc.) factors of brain edema onset have been identified. It turned out that the location of the affected focus determines the differences in neurogenic and neurohumoral mechanisms of the edema onset. The nearer the affected focus to the stem and diencephalic structures, the more marked the effect of neurogenic and neurohumoral factors and the more distinct the tendency towards edema generalization. Brain edema may be a cause of critical conditions and lethal outcomes only when it leads to dislocation and strangulation of them brain structures, and disturbances of brain metabolism and blood flow.

Brain Edema↗
PubMedDate not supplied

[Postoperative edema in brain tumors].

CT examination of postoperative edema of the brain in 251 neurosurgical patients showed edema to be determined by the location and histostructure of the tumor. The data obtained suggested that the pathogenesis of edema differs. Thus, vasogenous edema develops predominantly after removal of hemispheric gliomas, cytotoxic (hypoxic) edema--after removal of basal-diencephalic tumors, and hydrostatic edema--after removal of subtentorial tumors. It is shown that operative trauma causes hyperhydration of all brain structures.

Adult↗
PubMedDate not supplied

[The level of middle molecules in endogenous intoxication in neurosurgical patients].

The article deals with the results of study of the level of medium-size molecules in blood and urine of neurosurgical patients in the early postoperative period. It correlated with the severity of the patients' condition and with the values of osmolarity and the level of consciousness in a complicated postoperative period and a fatal outcome. The presence of pyoseptic complications may be judged according to the P value and prognosticated.

Blood Donors↗
PubMedDate not supplied

[Regulation of carbohydrate metabolism in patients with tumors of the sellar-diencephalic area before and after surgery].

Clinical and biochemical examination conducted in 40 patients with tumors of the sellar-diencephalic region before and after operation and in 8 healthy individuals revealed in the patients disorders of the function of the hypothalamus and alpha- and beta-cells of the pancreas in the presence of neurological and endocrine disorders. Radioimmunologic determination of insulin and glucagon in the blood disclosed activation of alpha- and beta-cells of the islets of Langerhans in patients with normal blood glucose content before surgery and inadequacy of the reaction of the pancreatic alpha- and beta-cells to the operation stress in patients with diminished or increased concentration of glucose in blood before surgery. Dysfunction of the hypothalamus and endocrine cells of the pancreas in tumors of the sellar-diencephalic region gives grounds for applying postoperative corrective therapy including preparations of insulin and glucagon in patients with progressive signs of a brain lesion.

Adult↗
PubMedDate not supplied

[Mechanism of glucose tolerance disorders in tumors located in the sellar-diencephalic area].

Clinical and biochemical examination carried out in 20 patients with tumors of the sellar-diencephalic area and 10 healthy persons revealed a dependence between functional disorders of the thalamus and hypophysis and the pancreatic beta-cells, which was attended by the development of obesity in patients with large endosuprasellar tumors of the hypophysis and diminution of glucose tolerance in all patients. Hyperinsulinemia revealed during intravenous glucose tolerance test and reduced glucose tolerance are evidence of relative insular insufficiency and substantiate pathogenetically the inclusion of insulin in the complex of intensive therapy applied in the early postoperative treatment of patients with tumors located in the sellar-diencephalic area.

Adult↗
PubMedDate not supplied

[Features of the hormonal regulation of water-electrolyte balance in patients with tumors of the chiasmatic-sellar area in the early postoperative period].

The response of water-electrolyte metabolism regulating hormones to neurosurgical stress was studied in 54 patients with tumors of the chiasma-sellar area of the brain. Three types of responses of hormones (the activity of renin, aldosterone, cortisol, and vasopressin) were revealed. Type I was characterised by a sharp activation of the hormones studied, type II by an absence of a response, type III by activation of renin and aldosterone and a decrease in vasopressin activity. Responses of types II and III were attended by deep disorders of water-electrolyte balance. The work substantiates the necessity of taking into account the state of the humoral mechanisms of regulation in conducting intensive therapy in neurosurgical patients.

Adolescent↗