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Biomedical subjects

O I Gurina

Publications and source records attributed to O I Gurina.

At least 19 recordsLinked to original sources

[Elimination of neurospecific proteins from CNS: pathogenetic and methodical aspects].

Appearance of neurospecific proteins (NSP) outside the brain plays a certain pathogenetic role in the development of autosensitization occurring in many kinds of CNS injuries and diseases. Analysis of modern views of cerebrospinal fluid (CSF) exchange allows us to suppose that NSP are eliminated from the brain tissue within CSF, moving from the subarachnoid space into cranial veins, and by lymphatic way, into deep cervical lymph nodes. Elevation of NSP level in CSF indicates an actual neudegenerative process. Serum levels of NSP are determined by the balance between the elimination of NSP from the brain, on the one hand, and their metabolism and the response of the immune system to the appearance of these autoantigenes in the blood stream, on the other. Basing on their own data on the dynamics of NSP (NSE, GFAR, and MBP) concentrations and the proportions of these proteins in CSF and serum (coefficient of elimination) in rats after ischemic, hypoxic, and autoimmune cerebral lesions, the authors offer an algorithm of pathogenetic evaluation, including, on the one part, a conclusion on the presence or absence of a neurodegenerative process, and, on the other, a conclusion on a normal or lowered rate of NSP elimination (metabolism). The results of such an analysis may have a clinical significance in terms of the development of a pathogenetic therapy, including, in every individual case, not only neuroprotectors, but also pharmaceuticals directed towards correction of the functional condition of the immune system.

Animals↗

Selective accumulation of monoclonal antibodies against neurospecific enolase in brain tissue of rats with middle cerebral artery occlusion.

Preparations of I(125)-labeled monoclonal antibodies against neurospecific enolase and mouse plasma IgG1 were injected intravenously to rats immediately after unilateral occlusion of the middle cerebral artery. Radioactivity of I(125)-labeled monoclonal antibodies against neurospecific enolase in the brain tissue progressively increased, reached a maximum by the 48th hour, and remained practically unchanged after 72 h. At the same time radioactivity of labeled IgG1 in the brain tissue and radioactivity of both preparations in the blood, liver, spleen, kidneys, heart, and lungs decreased over 72 h. Selective accumulation of I(125)-labeled monoclonal antibodies against neurospecific enolase was less significant in the brain tissue of the contralateral hemisphere and cerebellum not exposed to ischemia.

Animals↗

Enzyme immunoassay of NSE and GFAP as the criterion of dynamic evaluation of the rat blood-brain barrier in perinatal hypoxic ischemic injury of the CNS.

Enzyme immunoassay of the serum neurospecific antigens (gliofibrillar acid protein and neurospecific enolase) was used for evaluation of the resistance of the blood-brain barrier in Wistar rats with perinatal hypoxia and ischemia of the CNS. Perinatal hypoxia and ischemia of the CNS was modeled by two methods: ligation of the common carotid artery in 7-day-old rats followed by 3.5-h hypoxic hypoxia or 15-min anoxic exposure of fetuses isolated via hysterectomy on day 21 of gestation. Enzyme immunoassay of serum gliofibrillar acid protein and neurospecific enolase in control an experimental rat pups was carried out once a week during 3 months. In controls serum levels of gliofibrillar acid protein and neurospecific enolase virtually did not change during postnatal development, while in animals with cerebral hypoxia and ischemia induced in fetuses by both methods serum concentration of neurospecific enolase sharply increased 1 week after the injury and increased on weeks 6 and 10. The content of gliofibrillar acid protein was maximum on week 1 and later considerably varied, the peaks of its concentrations observed on weeks 3 and 8 preceded the increase in neurospecific enolase activity in peripheral blood.

Animals↗

Immunoenzyme assay of glial fibrillary acidic protein for evaluation of functional activity of cell grafts from embryonic ventral mesencephalon in rats with experimental hemiparkinsonism.

The relationship between the release of glial fibrillary acidic protein (GFAP) into systemic circulation and the efficacy of transplantation of embryonic nervous tissue was studied on rats with 6-OHDA-induced hemiparkinsonism. It was found that intrastriatal transplantation of cell preparations from embryonic ventral mesencephalon significantly attenuated apomorphine-induced rotation, which points to functional recovery of the dopaminergic nigrostriatal system. The degree of this recovery depends on reactive astrogliosis around the graft and survival of dopaminergic neurons. Analysis of GFAP concentration revealed significant elimination of this antigen into the circulation 7 and 14 days after transplantation. In rats with good consolidation of the graft without pronounced reactive gliosis, the concentration of GFAP reached 253.99+/-79.30 ng/ml on week 4 after transplantation and decreased to 8.2+/-3.3 ng/ml 8-12 weeks after transplantation. In rats with poor graft consolidation associated with death of transplanted neurons and gliosis in the graft and surrounding tissue the concentration GFAP increased to 476.4+/-111.0 ng/ml within 4 weeks after transplantation and remained elevated (235.0+/-44.8 ng/ml) for 12 weeks. Thus, monitoring of serum GFAP concentrations allows in vivo evaluation of the functional state of intracerebral graft and the level of reactive gliosis. This test can be used for the prognosis of transplantation efficacy.

Animals↗

Monoclonal anti-GFAP antibodies: extraction, characteristics, and immunoenzyme assay.

Methods of GFAP purification and obtaining of hybridoma cells producing monoclonal anti-GFAP antibodies and properties of GFAP preparation were described. The immunobloting data on specificity of obtained monoclonal antibodies are presented. A new method of GFAP immunoenzyme assay based on GFAP preparation and anti-GFAP antibodies was elaborated. Standardization of the immunoenzyme system was shown in tests for specificity, accuracy, and reproducibility.

Animals↗

Immunochemical assay of glia-specific antigens as a criterion for blood-brain barrier permeability in rats during acute intoxication with sodium barbital.

Enzyme immunoassay showed penetration of two glia-specific antigens, glial fibrillar acid protein GFAP and specific brain glycoprotein alpha(2)GP, through the blood-brain barrier in rats treated with toxic doses of sodium barbital. The permeability of the blood-brain barrier was completely normalized 3 days after treatment. This method can be used in clinical practice for evaluation of the severity of impairment and dynamics of normalization of blood-brain barrier properties during acute intoxication with barbiturates.

Animals↗

Biochemical parameters in the diagnosis and monitoring of neurotoxicity of antitumor cytostatics.

The significance of neurospecific proteins in the diagnosis of neurotoxicity in patients with breast, lung, testicular, and ovarian cancer treated by taxane and cisplatin drugs was evaluated. The most pronounced increase in the content of these proteins and titers of autoantibodies to these proteins was observed in patients with clinical manifestations of neurotoxicity induced by cytostatics. A strong correlation was found between the concentration of myelin basic protein and cumulative dose of the drug (R=0.922; p<0.0001). These data suggest that myelin basic protein and gliofibrillar acid protein can be used as markers in the diagnosis and monitoring of antitumor drug neurotoxicity.

Antineoplastic Agents↗

[Comparative clinico-immuno-chemical analysis of remittent and secondary-progressive course of multiple sclerosis].

Immunochemical monitoring of remittent and secondary-progressive course of multiple sclerosis (MS) was performed. Examination of 61 patients was performed during 3 years. Inflammatory cytokines: (IL-1, IL-2, IL-6, TNF-alpha), were measured in supernatants of the peripheral blood mononuclear cells while some neurospecific proteins (GFAP and alpha 2-GP), vesicular-cellular molecules of the adhesion (sVCAM-1) were estimated in blood serum. 50 healthy donors entered the control group. The results demonstrated a remaining functional tension of cell immunity and a decrease of the resistance of hematoencephalic barrier (HEB) at all MS stages. However, in secondary-progressive MS concentration of the sVCAM-1 in blood serum was elevated as compared with the control group, patients with remittent course and in clinical improvement. It is suggested that some functional alteration of HEB endothelium, manifest in constant pathologic expression of sVCAM-1 molecule, is one of the pathochemical mechanisms promoting progression of MS process.

Adolescent↗

[Clinical and immunochemical characteristics of remittent multiple sclerosis].

Immunochemical monitoring was used to examine 37 patients with remittent multiple sclerosis (MS) for 3 years. There were changes in the blood concentrations of the supernatants IL-1 beta, IL-2, IL-6, alpha-TNF, in the serum levels of the adhesion molecule sVCAM, the neurospecific proteins GFAP and alpha 2GP. Only does active MS show a simultaneous increase in the serum concentrations of SVCAM and GFAP and alpha 2GP, which may be used as a test for the objectification of MS aggravation, the efficiency of therapy. The revealed higher secretion of antiinflammatory of cytokines at all disease stages, no recovery of blood-brain barrier responsiveness and at remission provide evidence for the likelihood of a permanent immunopathological process in MS with prevailing inflammatory and destructive changes during a clinical exacerbation and of the induction of active astrogliosis at its remission.

Adolescent↗

PEGylated immunoliposomes directed against brain astrocytes.

Polyethylene glycol (PEG)ylated (stealth) immunoliposomes directed against human gliofibrillary acidic protein (GFAP) were prepared by coupling the thiolated monoclonal anti-GFAP antibodies with a maleimide derivative of phosphatidyl ethanolamine of the liposomal membrane. Experiments with cell cultures demonstrated specific and competitive binding of these immunoliposomes to embryonic rat brain astrocytes. Administered intravenously into rats, the immunoliposomes displayed typical kinetics with elimination half-lives of 8-15 hr. Being incapable of penetrating the unimpaired blood-brain barrier (BBB), these immunoliposomes, nevertheless, may be useful in delivering drugs to glial brain tumors (which continue to express GFAP) or to other pathological loci in the brain with a partially disintegrated BBB.

Animals↗

[Myelin basic protein. Structure, properties, function and role in diagnosing demyelinating diseases].

Physico-chemical properties and biological role of myelin basic protein (MBP)--one of the main myelin membrane proteins are reviewed. The data on MBP phosphorylation, methylation, fatty acid acylation and on interaction with lipid molecules in the human and animals bodies are presented. Much attention has been paid to the discussion of the diagnostic and clinical significance of the MBP, as the marker of demyelinating process in the central and peripheral nervous system.

Demyelinating Diseases↗

[Criteria of efficiency of transplantation of embryonic nervous tissue preparations in rats with 6-OHDA-impaired dopaminergic nigrostriatal system].

Effectiveness of transplantation of cells from embryonal nervous tissue of the ventral mesencephalon (VM ENT) and striatum (STR ENT) by apomorphin-induced motor asymmetry (APO-test), consolidation of the transplant (the degree of glyal reaction and amount of dopaminergic neurons) and blood serum levels of GFAP was studied for 3 months in Wistar rats with 6-OHDA-impaired dopaminergic nigrostriatal system. Marked therapeutic effectiveness was registered in VM ENT transplantation in the denervated striatum and in combined transplantation of VM ENT into the lateral cerebral ventricle simultaneously with STR ENT transplantation in the striatum. Separate transplantation of VM ENT in the lateral ventricle and STR ENT in the striatum had no positive effect on recovery of the dopaminergic nigrostriatal system. A correlation was found between the degree of glial reaction of ENT transplants, severity of rotation asymmetry and serum levels of gliofibrillary protein (GFAP). GFAP in the serum for lifetime assessment of transplant consolidation and prognosis of neurotransplantation efficiency was assayed.

Animals↗

[Monoclonal anti-NSE-antibodies: purification, characterization, and immunoenzyme analysis].

The results of NSE purification procedure, as well as hybridoma technology of anti NSE monoclonal antibodies synthesis are presented. The employment of this procedure yielded highly purified NSE preparation. The immunization of BALB/C mice with NSE preparation led to sensitization of the immunocompetent cells, which could form hybridomes, producing the anti-NSE monoclonal antibodies, after the confluence with myeloma cells Sp 2/0-Ag 14. The ELISA test-system for NSE analysis was developed on the basis of highly purified NSE preparation and monoclonal anti-NSE antibodies. This system was characterized by high specificity, accuracy and reliability. This system may be recommended for analysis of blood-brain barrier functions in the neurological and psychiatric diseases.

Animals↗

[Production and characteristics of PEGylated immunoliposome transport vectors specific for neural tissue astrocytes].

PEGylated (stealth) immunoliposomes covalently linked to antibodies against human gliofibrillary acidic protein (GFAP) were prepared by coupling the thiolated monoclonal anti-GFAP antibodies, D4, with a maleimide derivative of the phosphatidyl ethanolamine of the liposomal membrane. Depending on the initial protein-to-lipid ratios, the immunoliposomes prepared (with a diameter of about 70 nm) were coupled with 60 to 240 molecules of the antibodies. In vitro experiments with cultures of the embryonic rat brain astrocytes demonstrated a specific binding of these immunoliposomes, which could be inhibited by the preincubation of the cells with free non-coupled D4 but not with non-specific antibodies. Administered intravenously into rats, the immunoliposomes exhibited a kinetic behaviour typical for the PEGylated liposomes: after 24 h, approximately 20% of the doses injected were still present in the blood; the elimination rate constants were 0.05-0.09 h(-1), the elimination half-lives were 8-15 h. With such a systemic longevity, as well as with such a specificity, these immunoliposomes, non-penetrating through intact blood-brain barrier (BBB), should be useful in delivering pharmacological agents to glial brain tumours (which continue to express GFAP) or to other pathological loci in the brain with a partially disintegrated BBB.

Animals↗