Motor and Cognitive Functions in Aging C57BL/6 Mice: Association with Activity of the Monoaminergic Systems in the Cerebellum and Frontal Cortex.

The activity in the open field, short- and long-term memory in the novel object recognition test, and gait features were evaluated in 6- and 12-month-old male C57BL/6 mice. The levels of norepinephrine, dopamine, serotonin, and their metabolites were determined in the cerebellum and frontal cortex. In the observed age range, a decrease in locomotion speed, impairment of gait initiation and stability, and long-term memory deficit were revealed. In the cerebral cortex, reduced levels of dopamine and its metabolites and accelerated metabolism of all neurotransmitters under study were found. In the cerebellum, the content of all studied monoamines was elevated, while dopamine metabolism was decelerated. Analysis of correlations between the neurochemical and behavioral parameters showed that the mechanisms of compensation of brain functions during the early aging may be associated with an increase in activity of the monoaminergic systems in the cerebellum.

Prognostic Model of Prehypertension Risk Based on Molecular Markers.

The prognostic models assessing the risk of prehypertension in coming 1-2-year period for 30-60-year-old subjects were developed with the help of computer recognition technology using 6 recognition methods. These models are based on the content of molecular markers in blood serum and the risk factors for the development of prehypertension in men and women who had "optimal" BP for last 3 years and in patients with newly diagnosed prehypertension. The models were compared for their prediction power. The most effective model was obtained with gradient boosting method based on the content of molecular markers. It is characterized with a high predictive power (ROC AUC=0.76), specificity (96.4%), and overall accuracy (86.6%) accompanied with close relationship between prognosis and actual symptoms of prehypertension (p=0.001).

Serum Level of HLDF24 Peptide as an Objective Marker of Prehypertension.

The concentrations of the key factors of molecular pathogenesis of prehypertension (angiotensin II, HLDF24, S100b, endothelin, autoantibodies to these molecules, and VEGF) were analyzed in subjects with optimal BP (<120/80 mm Hg) and prehypertension (120-139/80-89 mm Hg). Comparative and correlation analysis of the levels of these molecules was performed. A statistically significant decrease in HLDF24 level in prehypertension in comparison optimal BP was observed. Specific features and interactions between the studied factors in optimal BP and in prehypertension were studied. The mechanisms underlying the observed associations between serum concentration of HLFF24 and the development of prehypertension were discussed.

Studying the Specific Activity of the Amide Form of HLDF-6 Peptide using the Transgenic Model of Alzheimer's Disease.

The neuroprotective and nootropic activities of the amide form (AF) of the HLDF-6 peptide (TGENHR-NH2) were studied in transgenic mice of the B6C3-Tg(APPswe,PSEN1de9)85Dbo (Tg+) line (the animal model of familial Alzheimer's disease (AD)). The study was performed in 4 mouse groups: group 1 (study group): Tg+ mice intranasally injected with the peptide at a dose of 250 µg/kg; group 2 (active control): Tg+ mice intranasally injected with normal saline; group 3 (control 1): Tg- mice; and group 4 (control 2): C57Bl/6 mice. The cognitive functions were evaluated using three tests: the novel object recognition test, the conditioned passive avoidance task, and the Morris water maze. The results testify to the fact that the pharmaceutical substance (PhS) based on the AF of HLDF-6 peptide at a dose of 250 µg/kg administered intranasally efficiently restores the disturbed cognitive functions in transgenic mice. These results are fully consistent with the data obtained in animal models of Alzheimer's disease induced by the injection of the beta-amyloid (ßA) fragment 25-35 into the giant-cell nucleus basalis of Meynert or by co-injection of the ßA fragment 25-35 and ibotenic acid into the hippocampus, and the model of ischemia stroke (chronic bilateral occlusion of carotids, 2VO). According to the overall results, PhS based on AF HLDF-6 was chosen as an object for further investigation; the dose of 250 µg/kg was used as an effective therapeutic dose. Intranasal administration was the route for delivery.

Pattern of Notch2, Numb, and Cas8 Gene Expression in Relevant Structures of the Rat Brain during Formation of Spatial Memory.

The expression of Notch2, Numb, and Cas8 genes, whose protein products are involved in regulation of neurogenesis/neuroapoptosis processes, was studied in the relevant cerebral structures of male Wistar rats trained in a spatial habit. The formation of long-term spatial memory was found to be associated with the formation of a specific pattern of transcription activity of the studied genes in different brain structures. The maximum expression of Notch2 gene was found in the hippocampus and cerebellum, the maximum expression of Numb was detected in the prefrontal cortex and cerebellum, and the maximum expression of Cas8 was revealed in the prefrontal cortex of trained animals.

Molecular markers of arterial hypertension in patients with normotony, pre-hypertension and hypertension.

We studied concentrations of angiotensin II, HLDF24 peptide, endothelin proteins, S100B, and autoantibodies to them and serum levels of blood natriuretic peptide in patients with different categories of "normal" arterial BP and hypertension. The relationship between blood levels of the above factors and normotony, pre-hypertension, and hypertension in the examined groups was analyzed. The results suggest that the studied molecular factors can serve as potential predictors of arterial hypertension and used for personalized hypertension risk assessment.

Content of S100b protein, HLDF24 peptide and autoantibodies to these factors as potential biomarkers for arterial hypertension in blood serum of healthy people.

The content of S100b protein, HLDF24 peptide, and autoantibodies to these factors in blood serum was measured in healthy individuals (35-64-year-old men and women) with various levels of "normal" BP. Significant differences in the amount of these molecular factors were found in individuals with various categories of BP. We revealed age-related and gender differences in the content of molecular factors in the serum. Our results indicate that variations in the concentration of S100b, HLDF24, and autoantibodies to these factors in blood serum from adult people can serve as a reliable criterion for the risk of arterial hypertension.

[Spontaneous enhancement of long-term memory retrieval during a few days after training].

The dynamics of long-term memory retrieval on the 1st and 5th days after rat training in spatial Morris water maze and snail conditioned taste aversion models was studied. It was found that animals trained for several days displayed stable and high level of memory retrieval both on 1st and on 5th days after training. Under conditions of single-session training the rate of memory retrieval in snails and rats on the 5th day was higher than on the 1st day after training. It has been proposed that spontaneous enhancement of habit retrieval during 5-days time interval after training is a result of "lingering" memory consolidation processes, which includes trace reorganization in particular molecular and morphological changes in animal brain neurons.

Delayed effects of NMDA receptor antagonist MK-801 on storage and reconsolidation of spatial memory in rats.

We studied the effects of NMDA receptor antagonist MK-801 on the storage and reconsolidation of spatial memory in Morris water maze in adult rats. MK-801 (50 µg/kg) administered 24 h after the completion of training was shown to improve the resistance of spatial memory to spontaneous extinction, while reminder against the background of MK-801 suppresses its ameliorating effect on memory storage. The detected behavioral effects of MK-801 persisted over 60 days after administration and can be associated with its influence on coupled neurogenesis/apoptosis processes induced during memory trace formation in adult animals.

Involvement of HLDF protein and anti-HLDF antibodies in the mechanisms of blood pressure regulation in healthy individuals and patients with stable hypertension and hypertensive crisis.

We studied the relationships between the blood serum levels of human leukemia differentiation factor HLDF, idiotypic and anti-idiotypic antibodies to HLDF, and clinical indicators of cardiovascular function in apparently healthy individuals and patients with essential hypertension and cerebral hypertensive crisis. Markedly reduced HLDF levels and anti-HLDF antibody titers were found in the blood of the examined patients. Correlations between HLDF levels, duration of hypertension, and systolic and diastolic BP were revealed. These findings suggest that the studied molecular factors are involved in the mechanisms of BP regulation under normal conditions and during hypertension development. The protein HLDF and anti-HLDF antibodies can be considered as biomarkers for early diagnosis of hypertension and its cerebral complications.

Specific changes in c-fos expression and colocalization with DNA in identified neuronal nuclei of edible snail following neurotransmitter application.

The effects of serotonin and glutamate on c-fos expression and c-Fos colocalization with DNA were immunohistochemically studied in defense behavior command neurons R-LPa2-3 in snail Helix lucorum. Simultaneous neurotransmitter application resulted in increased c-Fos-immunoreactivity and colocalization with DNA-specific stain Hoechst 33342 in LPa2 and RPa2 neurons with specific dynamics for each identified cell. In the nuclei of LPa3 and RPa3 neurons, neurotransmitter application did not significant change the c-Fos level. These findings are indicative of specific spatiotemporal changes in c-fos expression and c-Fos colocalization with DNA in investigated neurons of edible snail under the influence of neurotransmitters.

Regional features of the expression of genes involved in neurogenesis and apoptosis in the brain of adult rats.

The expression of mRNA of genes involved in neurogenesis and apoptosis (Apaf1, Ascl1, Bax, Bcl2, Casp3, Casp8, Casp9, Dffb, Myh10, Naip2, Napa, Notch2, Numb, Pura, S100a6, Tnf) in the prefrontal cortex, hippocampus, and cerebellum was studied in adult rats. The content of mRNA of these genes (except Apaf1) was several-fold higher in the cerebellum than in the hippocampus and brain cortex. In the hippocampus, the expression of Apaf1 was significantly lower than in the prefrontal cortex, while the expression of Ascl1, Pura, S100b, and Tnf was higher. Regional differences in the direction, strength, and numbers of significant correlations between the expression of the studied genes were detected. Documented differences in gene expression were regarded as validation of the structural and functional cooperation of neurogenesis and apoptosis at the molecular genetic level.

Neurogenesis enhancer RO 25-6981 facilitates repeated spatial learning in adult rats.

The effects of Ro 25-6981 (selective NMDA receptor blocker) in a dose stimulating neurogenesis on repeated learning, reversal learning, and memory reconsolidation were studied in adult rats in Morris water maze. Ro 25-6981 facilitated repeated learning 13 days after injection, but did not influence reversal learning. The blocker injected directly before reminder did not disturb repeated learning and reversal learning in Morris water maze. These effects of Ro 25-6981 on the dynamics of repeated learning seemed to be due to its effects on neurogenesis processes in adult brain.

[Effects of the neurogenesis stimulator Ro 25-6981 upon formation of spatial skill in adult rats depend on the term of its administration and the animals' ability to learn].

Effect of administration of selective N-methyl-D-aspartate (NMDA) receptor antagonist Ro 25-6981 on learning and memory in a dose which is known to stimulate neoneurogenesis was assessed in adult rats with different abilities to formation of spatial skills in different time periods after the antagonist injection. Wistar male rats were trained to find hidden platform in the Morris water maze for 5 consecutive days. Rats' learning ability for spatial skill formation was evaluated depending on platform speed achievements. In re-training sessions (cues and platform location changed), it was found that all rats received Ro 25-6981 13 days before the re-training demonstrated impaired spatial memory. At the same time the inhibitor injected 29 days before re-training selectively facilitated the formation of spatial skill in animals with initially low learning abilities.

Irreversible amnesia in rats and edible snails under conditions of associative memory reconsolidation disturbance caused by NMDA-glutamate receptor antagonist.

The effect of MK-801, an antagonist to NMDA-glutamate receptors, on reconsolidation of olfactory discrimination task in rats and taste discrimination in edible snails was examined. Twenty-four hours after conditioning, the animals received a single systemic injection of MK-801 followed by a reminding conditional stimulus. Disturbances in retrieval of the acquired task were observed 10 days after injection followed by a reminding procedure. Repeated conditioning of these animals did not restore the task. Injection of MK-801 without reminding stimulation had no effect on task retention. Thus, disturbances of NMDA-dependent reconsolidation of the associative memory in animals of different taxonomic groups irreversibly eliminated long-term memory.

[Serum immunoboichemical markers in patients suffered with hypertension-induced cerebrovascular diseases].

Complex evaluation neurotrophic protein S100b, differentiation factor HLDF, idio-and antiidiotypic antibodies against these proteins in patient sera with hypertension-induced cerebrovascular disorders was performed by ELISA. In patients with essential hypertension, cerebral hypertensive crisis and ischemic stroke S100b and anti-S100b concentration was found to be higher, whereas HLDF and anti-HLDF ones were lower compared with control. Different dynamics of S100b, HLDF content and antibody level was shown within 21 days of observation. These findings may be useful in further diagnostic and prognostic studies of hypertension-induced cerebrovascular disorders.

Specific features of molecular postsynaptic excitation processes of different sensory modalities in edible snail neurons.

Stimulations of different sensory modalities result in selective activation of second messengers and genes controlled by them in defensive behavior command neurons (LPl-1 and RPl-1) in edible snail. Excitation induced by stimulation of chemoreceptors of snail head results in cAMP accumulation in command neurons and induction of associated transcriptional factors of immediate early gene C/EBP, whereas regulating mechanisms of another sensory input mediating excitation after tactile head stimulation, involve protein kinase C and associated transcriptional factor SRF. These findings reflect specific features of postsynaptic processes providing excitation of different sensory modalities converging to defensive behavior command neurons in edible snails.

[Clinical and epidemiological study of lacrimal neoplasms].

A cross-sectional mass epidemiological survey of 18,320 urban and rural citizens of the Republic of Tadjikistan revealed 31 patients with orbital tumors, of which lacrimal neoplasms were determined in 4 (0.022% in the general population and 12.9% of the identified orbital tumors). According to the referral data, the prevalence of lacrimal neoplasms was 1.03% of all the tumors of the organ of vision and 5.26% of the orbital neoplasms. Epithelial tumors were more common (52%), their malignant forms dominated over benign ones (55.7% versus 44.3%). Inflammatory processes (22.6%) as acute and chronic dacryoadenitis (9.5%) and pseudotumors (13.1) were the second most common conditions. Lymphoid tissue tumors (13.6%), cystoid masses (8.6%), and neoplasms of unclear genesis (1.4%) were noticeably less prevalent. The severest difficulties in recognizing lacrimal epithelial tumors were to clinically and morphologically identify what determined the specific features of the lacrimal structure and evident structural polymorphism. With the higher grade of anaplasia, the likelihood of a recurrence of a tumor and the rate of its growth increased (r = +0.83). The survival rates closely correlated with the higher rates of recurrent adenocarcinoma and adenocystic cancer (r = -0.87).

[Morphological features of regenerative-reparative processes in the cornea exposed to synthetic analogues of endogenous peptide fragments of protein S100b in an experiment].

The effects of two 5-membered (SP5, SP6) endogenous synthetic peptide fragments of protein S100b on the course of regenerative-reparative processes in the corneas of Wistar rats were morphologically studied after making a graduated injury. Conjunctival or endonasal injection of the peptides was made at two concentrations of 10(-6) and 10(-8) M. The study peptides were found to have a modulating effect on regenerative-reparative processes regardless of the route of administration and to induce accelerated and qualitative corneal wound healing as compared with the controls. The specific feature of SP5 was the formation of a fibroblastic membrane. When SP5 was injected at a concentration of 10(-6) M, the membrane was more pronounced and occupied the whole area of keratectomy whereas when this peptide was administered at a concentration of 10(-8) M, its formation was observed in the deep and middle corneal layers. The most marked effect of SP6 revealed during the study was the formation of newly-formed vessels over the entire wound surface independently of the concentration of the injected substance. Of the two study peptide fragments, SP5 is, in the authors' opinion, promising for clinical application. Significant keratocytic proliferation noted in the use of SP5 at a concentration of 10(-6) M may be used to accelerate scarring when the sclera and cutaneous covering are damaged. The effects detected with administration of SP6 at two concentrations were regarded as negative as they did not answer the purpose set during the study performed.