Analysis of Visual Cognitive Impairments in Schizophrenia at the Early Stages of the Disease and Their Correction by Interactive Virtual Environment

The paper describes the results of studies aimed at evaluating the effect of interactive virtual environments on the visual system, including the magno-and parvo-systems. Analysis was conducted in patients diagnosed with paranoid schizophrenia diagnosed from one to five years ago. Comparative analysis of visual evoked potentials during the perception of images that differed in their semantic (animate/inanimate) and physical characteristics (filtration images at high/low spatial frequencies) was used for the assessment of the impact of virtual environments. The images of objects were filtered via digital filtration for selective effect on the magno-and parvo-channels of the visual system. To evaluate the function of visual perception, the measurement of contrast sensitivity using Gabor elements was used. At the early stages of schizophrenia, the patients exhibited a decrease in the amplitudes of the components of cognitive visual evoked potentials to stimuli filtered at high spatial frequencies and reduced contrast sensitivity at high spatial frequencies. The effect of virtual environments on the visual system resulted in a significant increase in the amplitude of the cognitive components of visual evoked potentials in the paradigm of presentation of images filtered at the high spatial frequencies, which allows the conclusion about a stimulating effect of the virtual environment on the parvo-system functioning. The activation of the magno-system occurred to a lesser extent. The present study represents the findings obtained by the studies of cognitive impairments in schizophrenia and the methods of their correction conducted at the Laboratory of Physiology of Vision of the Pavlov Institute of Physiology of the Russian Academy of Sciences and at the Laboratory of Neurobiology of Action Programming of the Bechtereva Institute of the Human Brain of the Russian Academy of Sciences.     

Effects of NaCl, Na2SO4, and mannitol on storage lipid mobilization in the cotyledons and roots of purple alfalfa seedlings

The effects of NaCl, Na₂SO₄, and mannitol on mobilization of storage lipids in the cotyledon mesophyll and root meristem cells during the germination of purple alfalfa (Medicago sativa L.) seeds were studied using the transmission electron microscopy technique. The ultrastructural analysis showed that the number and shape of specific organelles, oleosomes, depended on the osmotic effects of a salt used. In control seedlings grown on distilled water, lipid mobilization in roots terminated by the 4th day, and in cotyledons, only by the 8th day. The disruptions in the storage lipid mobilization in the treated seedlings were specific and depended on the stress agent used, the osmotic pressure induced by this agent, as well as on the tissue type. The presence of a great number of oleosomes in the cytoplasm of cells subjected to osmotic stress, in contrast to the control ones, demonstrated the inhibition of mobilization processes. All concentrations of Na₂SO₄ and mannitol suppressed lipid mobilization in the cotyledons and roots. At the same time, NaCl markedly suppressed this process in the root cells only at a higher osmotic pressure of the solution. The results obtained suggest that the cytological analysis of cotyledon storage-lipid mobilization can tentatively assess the resistance of dicotyledonous plants to abiotic stresses.     

Analysis of the interference electromyogram of the human soleus muscle under vibrational stimulation

The characteristics of EMG structure are studied for the voluntarily contracting human m. soleus against the background of vibrational stimulation. Averaging over the vibration cycle and spectral analysis are used. Averaging reveals EMG nonuniformity over the cycle; narrow peaks appear in the spectrum at the vibration frequency. EMG analysis proves informative at high vibration frequencies (70–120 Hz), while analysis of the rectified EMG proves informative at low frequencies (30–70 Hz). In the case of tibial ischemic blockade the peak disappears earlier than the tendon reflex. As the force increases, the peak amplitude normalized to the EMG power decreases. The peak rises with prolonged contraction under vibration. These effects are thought to reflect the changes in the relative contribution to the stimulating influx to the motoneurons of the part which is delivered via short connections from the muscle receptors.Institute for Problems of Information Transmission, Acdemy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 23, No. 1, pp. 57–65, January–February, 1991.     

Structural organization of chloroplast of tomato plants <Emphasis Type="Italic">Solanum lycopersicum</Emphasis> transformed by Fe-containing superoxide dismutase

In this work we analyzed the results of the transformation of tomato plants Solanum lycopersicum by gene FeSOD1 from Arabidopsis thaliana, equipped with the signal sequence for targeting into chloroplasts. PCR analysis showed that the gene was integrated into the genome of several tomato plants that underwent transformation followed by selection in the kanamycin-containing medium. Two lines, provisionally denoted as nos. 6 and 8, were selected from the independent transformants. Line 6 was characterized by a reduced growth rate and altered leaves and line 8, by normal growth and leaves typical for control plants. Both lines showed a significant increase in SOD activity. In line 8 the increase in SOD activity was accompanied by an increase of ascorbate peroxidase activity, and in line 6 this effect was not present. Electron microscopic analysis of parenchymal and guard cells of both lines was performed, with an emphasis on the ultrastructural organization of chloroplasts. It is shown that the chloroplasts of the two transgenic lines differ in the number and size of starch grains and deposited plastoglobules as well as in the organization of lamellae and grana. Taken together, the results indicate that the expression of the introduced gene FeSOD1 has a significant effect on metabolic processes in the plastids. The findings are discussed in relation to the hypothesis about the importance of low concentrations of ROS for the integration of structure and function of chloroplasts.     

CFTR Gene Variants and Genotypes in Russian Patients with CBAVD Syndrome

Russian Journal of Genetics - CBAVD syndrome is one of the common genetic causes of male infertility, associated with obstructive azoospermia, commonly resulting from pathogenic CFTR gene variants....     

Characterization of beam patterns of bottlenose dolphin in the transverse plane

The characteristics of absolute auditory sensitivity of the bottlenose dolphin (Tursiops truncatus) in the transverse plane have been measured using short broadband stimuli simulating dolphin clicks (with energy maximum at frequencies 8, 16, 30, 50 and 100 kHz). Experiments were performed using the method of conditioned reflexes with food reinforcement. It is shown that, in the frequency range of 8–30 kHz, the absolute sensitivity of dolphin hearing in any ventral and lateral directions of the transverse plane is only 2–8 dB worse than in the rostral direction. Moreover, it is 25–30 dB better than at 50–100 kHz. At 8–30 kHz, pronounced dorsoventral asymmetry has been observed. In this frequency range, it reaches 15–18 dB whereas at 50–100 kHz this asymmetry decreases to 2–3 dB. In the dorsal direction, the auditory sensitivity is 18 dB worse than in the rostral one at ∼8 kHz, and the difference rises smoothly to 33 dB at ∼100 kHz. At 50–100 kHz, the acoustical thresholds in the transverse plane relative to those for the with rostral direction get worse almost uniformly in all directions by 25–33 dB. As a result, in the transverse plane the beam patterns are nearly circular, unlike those at 8–30 kHz. The results are discussed in terms of the model of sound perception through the left and right mental foramens. The biological relevance of such asymmetry is emphasized.     

Mutation p.E92K is the primary cause of cystic fibrosis in Chuvashes

Molecular genetic study of the CFTR gene in cystic fibrosis patients from the Chuvash Republic is presented. We found linkage disequilibrium of the disease with 22-7-16-13 haplotype using intragenic markers. Major mutation p.E92K was revealed in chromosomes carrying this haplotype. The frequency of this mutation in Chuvash patients was 66.6%. Population study of the distribution of two mutations (p.E92K and F508del) of the CFTR gene revealed that their population frequency in heterozygous carriers was one per 37 subjects while calculated cystic fibrosis frequency in Chuvashia is one per 5420 newborns.     

Short-term fibronectin treatment induces endothelial-like and angiogenic properties in monocyte-derived immature dendritic cells: involvement of intracellular VEGF and MAPK regulation

Fibronectin (FN) is an extracellular matrix protein promoting cell proliferation, adhesion, and survival and is localized in the intimal layer of normal and atherosclerotic blood vessels. Dendritic cells (DCs) are potent antigen-presenting cells located in healthy and diseased intima, and thus may predispose arteries to atherosclerosis. Besides their pro-atherogenic activities DCs can promote neovascularization, by releasing pro-angiogenic mediators and/or by trans-differentiating into endothelial-like cells. Here, we investigated changes in morphology, function and angiogenic properties of monocyte-derived immature DCs (Mo-iDCs) after a short-term FN treatment and some of the signaling pathways involved in these processes. The cells were analyzed by time-lapse, confocal microscopy and flow cytometry. Within 90 min of re-plating, FN induced a swift morphologic transformation of most round iDCs into spindle-shaped iDCs (sp-iDCs). This was characterized by redistribution of mitochondria into dendritic spindles, decreased CD1c, and increased thrombomodulin (CD141) expression. Functionally, sp-iDCs acquired Ulex-europaeus-agglutinin-1 lectin binding, phagocytosis was decreased and intracellular (nuclear and cytosolic) vascular endothelial growth factor (VEGF) was increased. FN also induced ERK1/2 phosphorylation in round-iDCs, and p38MAPK phosphorylation in sp-iDCs. Inhibiting p38MAPK, but not ERK1/2, restrained the FN-induced transformation into sp-iDCs. Furthermore, FN-treatment of Mo-iDCs induced a paracrine angiogenic effect on endothelial tube formation, which was abolished by inhibiting ERK1/2 or VEGF. Inhibiting p38MAPK had no effect on endothelial tube formation. By contrast, in laminin-treated Mo-iDCs, which had round-shaped morphology, CD1c and CD141 expression was similar to control untreated cells, but intracellular VEGF levels were higher, and endothelial tube formation was an individual trait. We conclude that a short-term FN treatment induced angiogenic intracrine and paracrine properties in Mo-iDCs. This may act as an immediate protective mechanism to maintain vascular homeostasis. Moreover, inducing sp-iDCs by short term FN-treatment or ERK1/2 modulation might be considered as new approaches for regulating angiogenesis through the production/inhibition of pro-angiogenic mediators. Collectively, these findings may support a role for FN and Mo-iDCs in vascular function and angiogenesis.