[The neurotoxicity biomarkers as potential indicators of the spinal cord ischemia]. / Biomarkery neirotoksichnosti kak potentsial'nye indikatory ishemii spinnogo mozga.

The study aimed at assessing the level of glutamate receptors antibodies (Abs) in blood serum and cerebrospinal fluid (CSF) of patients with spinal cord ischemia along with traditional diagnostic approaches. MATERIAL AND METHODS: Forty patients with spinal cord ischemia (10 with spinal stroke and 30 with subacute and chronic course of the disease) were enrolled. After exclusion of some participants, 27 patients continued the study. Comparison groups included 30 patients with ischemic stroke and 30 patients with radiculopathy. The control group consisted of 15 healthy volunteers. All participants underwent a neurological examination and spinal cord magnetic resonance imaging (MRI). Abs to glutamate receptors (NR2 subunits of NMDA-receptors, AMPA/kainate receptors) were measured by ELISA. RESULTS: NR2 Abs in patients with spinal cord ischemia were significantly increased in serum (p=0.0001) and CSF (p=0.0005) compared to controls and comparison groups. The NR2 Abs reliably differentiated spinal cord ischemia compared to AMPA/kainate receptors and S100ß protein. On the other hand, increased levels of Abs to the AMPA/kainate have been detected in patients with a more severe impairment associated with extensive white matter damage. CONCLUSION: The results show the potential of the Abs to glutamate receptors assessment in the diagnosis of spinal cord ischemia and severity of the process.

[The biomarkers of cerebral ischemia as a new method for the validation of the efficacy of cytoprotective therapy]. / Biomarkery ishemii golovnogo mozga kak novyi metod dokazatel'stva éffektivnosti neirotsitoprotektorov.

AIM: To study blood plasma concentrations of NR2-peptide in patients with ischemic stroke (IS) to assess its diagnostic value as a biomarker of cerebral ischemia and determine the dynamics of the biomarker during treatment with cortexin. MATERIAL AND METHODS: One hundred and twenty patients, aged from 18 to 70 years, including 36 with transient ischemic attack (TIA) and 84 with IS in the carotid territory (n=70) and vertebral/basilar territory with the Wallenberg-Zakharchenko syndrome (n=14), were enrolled. The National Institute of Health Stroke scale (NIHSS) was used to assess neurological status. Blood plasma concentration of NR2-peptide was measured in all patients at admission and after treatment. All laboratory results were compared with neuroimaging (MRI, CT) data. RESULTS: Concentrations of NR2-peptide detected in all patients were higher than in controls (>1.5 ng/ml), p<0.0001. The direct correlation between NR2-peptide (from 3.38 ng/ml to 15.6 ng/ml) and ischemic lesion (from few to 80 mm) was observed. A decrease in NR2-peptide concentration (from 8.5 to 5,.9 ng/ml, p<0.0001) was noted in patients treated with cortexin after 10-day treatment course. CONCLUSION: NR2-peptide blood assay is a reliable hemotest of brain ischemia. Cortexin has a sufficient therapeutic efficacy.

[Role and place of biochemical markers in diagnosis of cerebral ischemic stroke].

In recent years neurologists pay special attention to biochemical markers of instrumental diagnosis of brain ischemia in its acute phase. Determination of specific biomarkers in the blood of patients at early stages of cerebral blood circulation disorders may be helpful in screening patients at high risk of stroke in the short-term period. We present a review of literature and an analysis of own data (over 200 patients) with chronic and acute cerebral blood circulation disorders on the possibility of using brain biomarkers in clinical practice. The diagnostic value of NR2-antibodies in stroke with ischemic volume 5-70 cm3 is approximately 95,9% and in transitory ischemic attacks--98%.

Detection of antibodies to opioid and glutamate receptors by latex agglutination and enzyme immunoassay.

We studied adsorption capacity of 5 latexes to synthetic peptide fragments of mu- and delta-opioid receptors and to GluR1 and NR2A subunits of glutamate receptor. Levels of autoantibodies to opioid receptors in the latex agglutination test and enzyme immunoassay were in good correlation. The level of autoantibodies to opioid receptors measured by these methods was increased in patients with opium narcomania, while the content of autoantibodies to the glutamate receptor subunits was increased in epileptics.

The effects of substance P after central administration on the activity of the mesolimbic system of the rat brain as studied by microdialysis.

In vivo microdialysis was used to study the effects of substance P on dopamine, dihydroxyphenylacetic acid, and homovanillic acid levels in the nucleus accumbens in rats. Each animal received sequential injections of physiological saline, 0.1 microg of substance P, and 1 microg of substance P into the lateral ventricle over three days. Dialysates showed increases in dopamine levels in response to neuropeptide, by 41% for the 0.1 microg dose and 71% for the 1 microg dose. The dynamics of these changes also depended on the concentration of the agent. Administration of 1 microg of substance P gave a peak dopamine level at 50 min; the neurotransmitter level remained significantly elevated 75 min after dosage with substance P. The dopamine level was increased only at 75 min when the 0.1 microg dose of neuropeptide was used. Changes in metabolite levels were also dose-dependent. After the 1 microg dose, the dihydroxyphenylacetic acid level increased by 28%, while the 0.1 microg dose produced no significant change in the level of this metabolite. The homovanillic acid level did not respond to administration of substance P at either dose. These data support the suggestion that the influence of substance P on the internal compensation system is to a significant extent mediated by dopaminergic mechanisms and provides a possible explanation for the effects of the neuropeptide seen in a conditioned place preference reflex.

[Determination of antibodies to opiate receptors by latex agglutination and immunoenzyme analysis]. / Opredelenie antitel k opiatnym retseptoram metodami latex-aggliutinatsii i immunofermentnogo analiza.

Adsorption ability of few kinds of latex covered by synthetic peptide fragments of mu- and delta-opiate receptors (OR) is investigated. The levels of autoantibodies to opiate receptors fragments in the blood serum of patients with drug abuse are detected by latex agglutination and ELISA. The patients with drug abuse demonstrated positive latex agglutination reaction for level specific antibodies from 10.4 mg/ml and higher in the 71.4% of cases. The levels of autoantibodies to OR in the blood of patients with drug abuse was in 2.8 times higher of control data. The correlation between levels of autoantibodies to opiate receptors obtained by methods of latex agglutination and ELISA is revealed. The obtained data confirms our hypothesis concerning existence of specific changes in immune system linked with some CNS disorders like drug abuse. Thus, the level of autoantibodies to opiate receptors could be used as new criterion for diagnostics of opiate abuse.

Expression of NMDA neuroreceptors in experimental ischemia.

The role of NMDA receptors in molecular mechanisms of neurotoxicity was investigated using rat models of global and focal cerebral ischemia. Expression of NR2A and NR2B receptor mRNAs up-regulated in cortex after 3 h of reperfusion following middle cerebral artery occlusion (MCAo). This effect was accompanied by an increase in NR2A and NR2B immunoreactivity. At six hours of reperfusion, drastic activation of NR2A mRNA expression was observed in the penumbra that returned to the control level at 24 h of reperfusion. The monitoring of NR2A autoantibodies in the blood of the experimental rats showed its reliable increase to the 5-6th day of reperfusion that maintained elevated to the 20th day of the experiment. The data indicate that NR2A and 2B receptor subunits and NR2A autoantibodies are biochemical markers of the neurotoxicity underlying cerebral ischemia.

[Effect of centrally administrated substance P on the brain mesolimbic system activity in rats as measured by microdialysis]. / Vliianie substantsii P posle ee tsentral'nogo vvedeniia na aktivnost' mezolimbicheskoi sistemy mozga krysy, po dannym mikrodializa.

Action of substance P on the contents of dopamine, dihydroxyphenylacetic acid and homovanillic acid in the nucleus accumbens of rats was investigated with microdialysis procedure. During 3 days, each animal daily received i.v. the saline (the 1st day), 0.1 mcg of substance P (the 2nd day), 1 mcg of substance P (the 3rd day). Elevation of accumbal dopamine was observed amounting up to 41% and 71% for 0.1 mcg and 1 mcg of substance P, resp. Rates and duration of these changes also depended on neuropeptide concentration. 1 mcg of substance P produced the dopamine elevation with a peak by the 50th min. Moreover, in 75 min. after infusion of the neuropeptide, the levels of dopamine still remained increased. Response of metabolites also proved to be dose-related. With 1 mcg of substance P, the contents of dihydroxyphenylacetic acid increased by 28%, while with 0.1 mcg of substance P, this parameter did not change. Contents of homovanillie acid was unaffected by central substance P at the above doses. The data obtained corroborate the assumption of influence of the substance P on the reward system arising from its dopaminergic properties and provide a possible explanation of the neuropeptide effects observed in the conditioned place preference paradigm.

Mechanisms of the influences of the central administration of substance P on ethanol consumption in chronically alcoholic rats.

The effects of central administration of substance P (SP) on alcohol consumption and dopamine metabolism in the projections of the mesocorticolimbic and nigrostriatal systems of the brain were studied in chronically alcoholic rats. Rats received 15% ethanol solution for 6 months without choice. Intraventricular administration of SP (1 microg/rat) decreased consumption of 10% ethanol solution by 41% compared with controls in an alcohol free choice test lasting one day. After chronic alcoholism, there was a decrease in the ratio of dihydroxyphenylacetic acid (DOPA) and homovanillic acid (HVA) to dopamine in the nucleus accumbens and striatum in rats subjected to alcoholism, as compared with intact controls. Chronically alcoholic rats treated with SP showed increases in DOPA, HVA, and the DOPA:dopamine and HVA:dopamine ratios in the nucleus accumbens as compared with animals given physiological saline, by 17%, 23%, 9% and 19% respectively. The only increases in the striatum were in the absolute levels of DOPA and HVA, by 28% and 29%, while the ratios of these metabolites to dopamine remained unchanged. Thus, central administration of SP decreased the voluntary consumption of ethanol in the ethanol free choice test and enhanced dopamine metabolism in structures of the mesolimbic and nigrostriatal systems in chronically alcoholic rats.

[The influence of substance P central administration on ethanol intake in rats chronically exposed to alcohol]. / Mekhanizmy vliianiia tsentral'nogo vvedeniia substantsii P na potreblenie étanola u khronicheski alkogolizirovannykh krys.

The influence of central substance P (SP) administration on alcohol intake and brain dopamine metabolism within mesocortico-limbic and nigrostiatal systems of rats exposed to ethanol, was studied. During 6 months, the rats consumed 15% ethanol solution instead of water. Central administration of SP (3 mcg/kg) decreased alcohol consumption by 41% in alcohol-preference animals. After long-term ethanol exposure ratios DOPAC/DA and HVA/DA were reduced in striatum and accumbens. SP in dose 3 mcg/kg increased content of DOPAC by 17% and HVA by 23% as well as DOPAC/DA by 9%, HVA/DA by 19% in accumbens. Whereas in striatum only increased DOPAC (28%) and HVA (29%) were observed as compared with saline-treated rats.

[Levels of autoantibodies to glutamate receptors and immunological blood parameters in patients with epilepsy]. / Uroven' autoantitel k sub''edinitsam glutamatnykh retseptorov i immunologicheskie pokazateli krovi u bol'nykh épilepsiei.

The role of glutamate receptors in the brain spiking activity was evaluated. The electroencephalographic (EEG) spiking activity was monitored and autoreactive antibodies (aAbs) to subunits of glutamate receptors were assessed in the blood serum of epileptic and ischemic stroke patients. We showed that the level of GluR autoantibodies in blood serum of patients correlates to the intensity of the brain paroxysmal activity. These data confirm our previous observations. The level of GluR1 aABs has been proposed as a specific biomarker typical for epilepsy. This approach could be recommended as an additional criterion for diagnostic of nervous diseases such as epilepsy and ischemic stroke.

[Effect of substance P on ethanol consumption in subchronically alcoholized rats in the limited scheduled access paradigm]. / Vliianie substantsii P na potreblenie étanola u subkhronicheski alkogolizirovannykh krys v teste ogranichennogo dostupa k alkogoliu.

The effect of substance P on alcohol intake was studied in rats using a limited scheduled access paradigm. Ascending doses of substance P (100 and 200 micrograms/kg) were administered intraperitoneally to rats approximately 30 minute prior to their 1-hour-per-day access to alcohol. Each dose was administered for 3 successive days, and the effect of substance P was compared to that of saline solution control. Substance P at the dose of 100 micrograms/kg had no effect on alcohol consumption but significantly decreased the alcohol intake at the dose of 200 micrograms/kg. Thus, substance P reduces the alcohol motivation of rats in a limited scheduled access paradigm.

[Significance of the level of auto-antibodies for the NMDA type glutamate receptors in diagnosis of chronic cerebral circulation disorders]. / Prakticheskoe znachenie opredeleniia urovnia autoantitel k NMDA-tipu glutamatnykh retseptorov v diagnostike khronicheskikh rasstroistv mozgovogo krovoobrashcheniia.

For studying diagnostic possibilities of a new laboratory test for cerebral ischemia (CIS-test), thirty patients have been examined. The level of autoantibodies to NMDA type glutamate receptors is shown to increase significantly (3-5 times) in patients with stage 2 dyscirculatory encephalopathy. Parallel measurements of free glutamate and homocysteine levels in the patients blood plasma did not reveal any substantial changes of the given parameters, comparing to indices of autoantibodies to NR2a glutamate receptor. The titer of autoantibodies to this receptor type did not change significantly in patients with epilepsy; the titer dependence on dyscirculatory encephalopathy severity level and its decrease during treatment have been found as well. The possibilities of CIS using for diagnosis and therapy control in patients with chronic cerebral circulation disorders are discussed.

[Level of autoantibodies to opiate receptors in blood of patients with opiate addiction]. / Issledovanie urovnia autoantitel k opiatnym retseptoram v krovi bol'nykh opiinoi narkomaniei.

The level of autoantibodies to opiate receptors was measured in serum of heroin addicts in withdrawal and in the period of long-term abstinence and in healthy volunteers as well. The level of autoantibodies was assessed with ELISA with synthetic peptide specific for subregions of mu and delta opiate receptors. The scores of the level of autoantibodies higher than 150% of the level noted in healthy volunteers was observed in 56% of heroin addicts. The dependence of autoantibodies level from duration of diseases was shown. Elevated level of opiate receptors autoantibodies were detected in the sera of 71% patients with opiate addiction who had been using heroin more then one year. High levels of opiate receptors autoantibodies were observed more frequently in patients with opiate withdrawal syndrome then in patients with long-term remission. Elevated level autoantibodies to opiate receptors were determined in the blood of 38% opiate abusers with remission for 3-8 months. The level of autoantibodies to opiate receptors may be used for diagnostics of heroin dependence and control of treatment efficiency.

Intracerebroventricular administration of substance P increases dopamine content in the brain of 6-hydroxydopamine-lesioned rats.

The interactions existing between substance P- and dopamine-positive neurons, notably in the basal ganglia, suggest that substance P may have therapeutic use in treatment of Parkinson's disease characterized by impaired dopaminergic transmission. The effects of intracerebroventricularly administered substance P were tested on the levels of dopamine and its metabolites in the striatum, nucleus accumbens and frontal cortex of 6-hydroxydopamine-lesioned rats. Intracerebroventricular injection of 6-hydroxydopamine decreased the levels of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the brain structures under investigation. Administration of substance P in low dose (0.35 nmol/kg) had no effect on the 6-hydroxydopamine-induced reduction of the dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid contents in the brain. However, treatment with substance P in higher dose (3.5 nmol/kg) increased the concentrations of dopamine and its metabolites in the striatum, nucleus accumbens and frontal cortex relative to saline-treated group. Additionally, 6-hydroxydopamine lesions significantly increased 3,4-dihydroxyphenylacetic acid/dopamine and homovanillic acid/dopamine ratios in the striatum and nucleus accumbens. Substance P (3.5 nmol/kg) partially reversed lesion-induced increases in 3,4-dihydroxyphenylacetic acid/dopamine and homovanillic acid/dopamine ratios in the striatum, but did not alter these ratios in nucleus accumbens. To test whether substance P fragmentation is responsible for this phenomenon, substance P(5-11), which is one of the main substance P fragments in rat CNS, was administered in equimolar dose. Substance P(5-11) was found to have no effect on the content of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the striatum and nucleus accumbens. In the frontal cortex, substance P(5-11) produced decreases in dopamine levels and increases in homovanillic acid/dopamine ratio. The results of this study suggest that substance P helps to restore dopamine deficit in the brain in an animal model of Parkinson's disease, with the positive effects being more prominent on the nigrostriatal than on the mesocorticolimbic dopaminergic system, but substance P(5-11) is not responsible for this effect.

Neuroprotective effects of glycine for therapy of acute ischaemic stroke.

The aim of this randomized, double-blind, placebo-controlled trial was to assess the safety and the efficacy of the pharmaceutic drug glycine in 200 patients with acute (<6 h) ischaemic stroke in the carotid artery territory. Fifty patients received placebo, 49 glycine 0.5 g/day, 51 glycine 1.0 g/day and 50 glycine 2.0 g/day for 5 days in each group. The efficacy of glycine was assessed by clinical analysis, by an enzyme-linked immunosorbent assay of levels of blood serum autoantibodies to NMDA-binding proteines, by detection of excitatory (glutamate, aspartate) and inhibitory (glycine, GABA) amino acid concentrations and lipid peroxidation products (TBARS) in CSF. The trial confirmed the safety profile of the glycine treatment. Slight sedation was observed in 9 patients (4. 5%) as a side-effect. Other marked side-effects or adverse events were absent. The glycine treatment at the dose of 1.0-2.0 g/day was accompanied by a tendency to a decreased 30-day mortality (5.9% in 1. 0 g/day glycine and 10% in 2.0 g/day glycine groups vs. 14% in the placebo and 14.3% in 0.5 g/day glycine groups), to an improved clinical outcome on the Orgogozo Stroke Scale (p < 0.01) and the Scandinavian Stroke Scale (p < 0.01) and to a favourable functional outcome on the Barthel index (p < 0.01 in 1.0 g/day glycine vs. placebo group in patients with no or mild disability). An early normalization of autoantibody titres to NMDA-binding proteins in serum was found (p < 0.01 vs. placebo), a reduction of glutamate and aspartate levels (p < 0.05 vs. placebo), an increase in GABA concentrations (p < 0.01 vs. placebo in severe stroke patients) and also a reduction of TBARS levels (p < 0.05 vs. placebo) in CSF by day 3. Thus, the trial suggests that sublingual application of 1.0-2. 0 g/day glycine started within 6 h after the onset of acute ischaemic stroke in the carotid artery territory is safe and can exert favourable clinical effects. These results will be verified in further trials with a larger number of patients.

[The use of the clinical biochemical Epitest kit in children with epilepsy]. / Primenenie kliniko-biokhimicheskogo nabora "Epitest" u detei s épilepsiei.

57 children aged 3-15 years were examined: children with epilepsy (n = 26), children with epileptic syndrome (n = 16) and children with other neurologic pathology (n = 15). Control group included 25 healthy children. Diagnostic efficiency of the epileptic test was investigated on the basis of the detection of autoantibodies (aAb) to glutamate receptor of AMPA type in blood serum of the patients. It was shown that children with epilepsy had elevated level of aAb to AMPA receptors in blood in comparison with that of the healthy children. The level of aAb to AMPA receptors correlated with severity of the disease and location of the epileptic focus. The authors recommend the "Epitest" as an additional biochemical tool for differential diagnosis of children's epilepsy.