Vibrissal inputs into the motor cortex of adult and developing rats

Field potentials (FP) and responses of single neurones to electrical stimulation of vibrissal pads have been recorded in motor cortex in the albino mature and developing rats. The FPs were characterized by 3-phasic shape and high stability in mature rats. The FPs evoked by contralateral stimuli have a range of onset latency of 4 to 24 ms (peak of distribution 8-11 ms); those to ipsilateral stimuli have a latency of 4 to 23 ms (peak of distribution 12-16 ms). Responses of single neurones were evoked with a latency of 9 to 20 ms. Usually, the FPs were evoked by both contralateral and ipsilateral stimulation, and in some tracks were effective only ipsilateral stimuli in the developing rats beginning from the 11th day of life. The FPs in such animals were less stable and more fatigable. During 2-4 weeks of life, FPs evoked by contralateral stimulation appeared with a latency of 15 to 46 ms; during the same period, a latency of single unit responses ranged between 20 to 33 ms. The FPs to ipsilateral stimuli appeared with a latency of 18 to 47 ms, a latency of single unit responses of 27 to 47 ms. The results indicate functional immaturity of vibrissal system up to the end of the first month of rat life.     

Psychophysiologic parameters of reproducing emotions in healthy subjects and patients during the first episode of depression

We analyzed the spectral power of EEG rhythms and some psychological features in patients with depression (first episode) and in healthy subjects. In the control group, the distributions of the spectral power of the alpha3 and gamma rhythms was symmetrical. In reproducing joy, the power of the alpha3 rhythm increased in the occipital and that of the gamma rhythm increased in the temporal areas of the left hemisphere. In depressive patients, predominant activation of the left posterior cortical quadrant in the alpha3 band was observed both in the baseline activity and during reproducing emotions of both valences. In these patients, the gamma rhythm predominated in the anterior regions of the right hemisphere during rest. The mental reproduction of joy and grief in depressive patients shifted the maximal gamma rhythm spectral power to the occipital cortical regions. Thus, in depressive patients, any emotional load, regardless of its valence, results in a decrease in the pathologic gamma activity and makes the distribution of cortical electric activity more close to that of healthy subjects.     

Comparison of the homologous SfeI and LlaBI restriction-modification systems

A fragment containing the SfeI restriction-modification system (RMS) operon was cloned from a Streptococcus faecalis SE72 plasmid. Nucleotide sequence analysis revealed its high (99.2%) homology to the operon for Lactococcus lactis subsp. cremoris W56 LlaBI RMS recognizing the same site, 5'-CTRYAG-3'. A substantial difference was that SfeI RMS operon had an additional 198-bp fragment and a larger gene for the putative control protein. No homology was observed between operon-flanking sequences of the two closely related species, suggesting horizontal transfer of the operon.     

Comparative Study of the M.BstF5I-1 and M.BstF5I-3 DNA Methyltransferases from the Bacillus stearothermophilus F5 Restriction–Modification System

The BstF5I restriction–modification system from Bacillus stearothermophilus F5, unlike all known restriction–modification systems, contains three genes encoding DNA methyltransferases. In addition to revealing two DNA methylases responsible for modification of adenine in different DNA strands, it has been first shown that one bacterial cell has two DNA methylases, M.BstF5I-1 and M.BstF5I-3, with similar substrate specificity. The boundaries of the gene for DNA methyltransferase M.BstF5I-1 have been verified. The bstF5IM-1 gene was cloned in pJW and expressed in Escherichia coli. Homogeneous samples of M.BstF5I-1 and M.BstF5I-3 were obtained by chromatography with different sorbents. The main kinetic parameters have been determined for M.BstF5I-1 and M.BstF5I-3, both modifying adenine in the recognition site 5"-GGATG-3".     

Immune system function in candidiasis patients

To compare the clinical picture and the immunological characteristics, 58 candidiasis patients differing by the severity and dissemination of the disease were examined. Chronic candidiasis of the skin and mucous membranes, the most severe and disseminated form of the disease, is associated with a decrease in the number of T-lymphocytes and changes in their subpopulations, as well as high titers of Candida albicans antigen and antibodies to it in blood sera. The immune system of patients with visceral candidiasis and chronic vulvovaginal candidiasis was similar to that of healthy persons in the characteristics under study. Immediate and mixed hypersensitivity occurred in candidiasis patients more frequently than in healthy persons. In extremely severe forms of Candida infection immediate hypersensitivity prevailed.     

Component parasite communities in the minnow Phoxinus phoxinus (L.) from ecologically safe and polluted reservoirs

A comparative analysis of the structure of component parasite communities in the minnow from ecologically safe or polluted to variable extent reservoirs was made. The analysis showed that the increase of the reservoir pollution by everyday drains, washings of fertilizers from the fields around and the dacha sections causes the change of dominant parasite species in the minnow, alteration of the sum of errors in the regression equation characterizing the spread of values of biomasses of the species forming the parasite community, and change of the "graphic" structure of the community. It is proved, that the high concentration of biogens has a destructive effect on natural systems, and at the same time causes the process of self-organizing, leading to the alteration of the community structure. As soon as even a small part of biogens is stopped to come into the reservoir, and the quality of environment is restored, the community restores its structure.     

Cloning of the Genes for DNA Methyltransferases of the SfaNI and Bst19I Restriction–Modification Systems and Primary Structure Analysis of Protein Products

The Streptococcus faecalis ND547 and Bacillus stearothermophilus 19 genes that code for DNA methyltransferases (MTases, M.) of restriction–modification (RM) systems with the same recognition sequence, 5-GCATC-3 were cloned and sequenced. The Bst19I RM system includes two MTases, M1.Bst19I and M2.Bst19I. The SfaNI RM system has only one MTase, M.SfaNI, whose N and C domains are homologous to M2.Bst19I and M1.Bst19I, respectively. Both M1.Bst19I and M2.Bst19I and the two domains of M.SfaNI contain conserved elements, which are arranged in the order characteristic of class N6-adenine MTases. The enzymes of the SfaNI and Bst19I RM systems proved to be highly homologous to their FokI and BstF5I counterparts, which was explained by the presence of the common tetranucleotide 5-GATG-3 in their recognition sites. Based on sequence homology, the spatial arrangement of highly conserved amino acid residues was determined using the known three-dimensional model of M.DpnIIA, which belongs to the same MTase class.     

M.BstF5I-2 and M.BstF5I-4 DNA Methyltransferases from BstF5I Restriction–Modification System of Bacillus stearothermophilus F5

The BstF5I restriction–modification system from Bacillus stearothermophilus F5 includes four site-specific DNA methyltransferases, thus differing from all known restriction–modification systems. Here we demonstrated for the first time that one bacterial cell can possess two pairs of methylases with identical substrate specificities (methylases BstF5I-1 and BstF5I-3 recognize GGATG, whereas methylases BstF5I-2 and BstF5I-4 recognize CATCC) that modify adenine residues on both DNA strands. Different chromatographic methods provide homogenous preparations of methylases BstF5I-2 and BstF5I-4. We estimated the principal kinetic parameters of the reaction of transfer of methyl group from the donor S-adenosyl-L-methionine to the recognition site 5"-CATCC-3" catalyzed by BstF5I-2 and BstF5I-4 DNA [N6-adenine]-methyl-transferases from the BstF5I restriction–modification system.     

M.BstF5I-4, the Forth DNA-Methyltransferase of the BstF5I Restriction–Modification System from Bacillus stearothermophilus F5

The fourth DNA-methyltransferase of the BstF5I restriction–modification (RM) system from Bacillus stearothermophilus F5 (M.BstF5I-4) was discovered, which modifies the adenine residue within the upper strand of the recognition site 5"-GGATG-3"/5"-CATCC-3". Thus, unlike other known RM systems, the BstF5I RM system comprises four genes encoding DNA-methyltransferases, three of which possess the same substrate specificity and methylate adenine within the 5"-GGATG sequence.