Effect of NMDA on production of reactive oxygen species by human lymphocytes.

Low concentrations (<20 microM) of N-methyl-D-aspartate (NMDA), an agonist of specific receptors of brain glutamatergic systems, promote the formation of reactive oxygen species (ROS) both in the whole blood and in lymphocyte fraction. Further increase in NMDA concentrations led to progressive increase in ROS content in the whole blood, but to its decrease in lymphocyte suspension. The activating effect of NMDA is abolished by antioxidant N-acetylcysteine (5 mM) and NMDA-type glutamate receptor antagonist MK-801 (5 microM).

[Effect of antenatal and postnatal hypoxia on the central nervous system and its correction with peptide hormones].

Ante- and postnatal acute hypoxia significantly aggravated the postnatal development. The posthypoxic behaviour patterns included hyperactivity and training ability inhibition typical for the attention deficit syndrome. A preventive injection of peptide constellation significantly improved the posthypoxic postnatal development and abolished the most of the negative modifications of behavioural patterns.

[Concepts of taxonomy and concepts of biodiversity: the problem of interaction].

There is, or there should be, an interaction between concepts of taxonomy and biodiversity. On the one hand, taxonomy develops some general and particular classificatory paradigms, which own diversity is to be taken into account to understand the nature of variety of natural kinds. On the other hand, analysis of the properties of biodiversity may put forward nontrivial problems for taxonomy that cannot be deduced directly from its own statements.

[Geometric morphometrics of the skull of various murid rodents (Mammalia, Rodentia): relation of the skull shape to the trophic specialization].

Presented is a brief overview of basic principles and notions of geometric morphometrics, a new approach to quantitative analysis of shape variations. This approach is applied to analysis of variation of the skull shape in the sample of 18 muroid genera belonging to the families Cricetidae, Arvicolidae and Gerbillidae. The skull shape is described by landmarks, and skulls are compared by resistant fit and superimposition methods.

Dipyridamole and its derivatives modify the kinetics of the electron transport in reaction centers from Rhodobacter sphaeroides.

A well known vasodilator dipyridamole (DIP), 2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4-d]pyrim idine, and its derivatives have recently been shown as potential co-activators (modulators) in the phenomenon of multidrug resistance (MDR) in cancer therapy. They inhibit the specific function of a transmembrane P-glycoprotein responsible for the ex-flux of anti-cancer drugs from tumor cells. To clarify molecular mechanisms of the anti-MDR activity of DIP and its two derivatives, RA25 and RA47, we have studied their effects on electron transport in reaction centers (RC) from purple photosynthetic bacteria Rb.

The effect of prolil-glycil-proline (PGP) peptide and PGP-rich substances on haemostatic parameters of rat blood.

The effect of intravenous and intranasal administration of proline-containing peptide, especially prolil-glycil-proline (PGP), on the haemostatic system of rats was investigated. Tripeptide PGP after single intravenous (0.2, 1.

Mass spectrometric determination of appearance energies for ions formed from CoF(4) and CoF(3) molecules.

Knudsen cell mass spectrometry was applied to the evaluation of the ionization efficiency curves for the ions originating from CoF(4) molecules. Cobalt tetrafluoride was obtained in the gas phase over the CoF(3)(s)-TbF(4)(s) system in the temperature range from 640 to 690 K. From the ionization efficiency curves the appearance energies of the ions formed from the CoF(4) molecules were determined by means of Vogt's deconvolution method.

[Peptides as inhibitors of thrombin coagulation activity and of thrombocyte aggregation].

The analysis of literature and our own data of regulatory peptides influence on the blood coagulation system is presenting. Various natural and synthetic peptides inhibit the activity of thrombin and platelet aggregation. Direct specific inhibitors of thrombin are peptides developed on the base of D-Phe-Pro-Arg sequence.

ATP-dependent proteolysis in mitochondria. m-AAA protease and PIM1 protease exert overlapping substrate specificities and cooperate with the mtHsp70 system.

To analyze protein degradation in mitochondria and the role of molecular chaperone proteins in this process, bovine apocytochrome P450scc was employed as a model protein. When imported into isolated yeast mitochondria, P450scc was mislocalized to the matrix and rapidly degraded. This proteolytic breakdown was mediated by the ATP-dependent PIM1 protease, a Lon-like protease in the mitochondrial matrix, in cooperation with the mtHsp70 system.

Comparative neurobiology of color vision in humans and animals.

Discrimination of colors was studied using an instrumental learning paradigm in monkeys (Macaque rhesus) and fishes (Carpio cyprinus L.). The confusion matrices composed of probabilities of instrumental responses were treated by factor analysis.

Sperm angiotensin-converting enzyme activity in Chernobyl victims and patients with chronic prostatitis.

The method for determination of angiotensin-converting enzyme activity in human spermatozoa and seminal plasma was developed. The number of total and active-motile spermatozoa was shown to be lower in Chernobyl victims than in healthy donors. The specific activity of angiotensin-converting enzyme in spermatozoa from Chernobyl victims was 12 times higher than that in donors.

Life span prediction from the rate of age-related DNA demethylation in normal and cancer cell lines.

A method has been proposed for the Hayflick Limit prediction by the analysis of the 5-methylcytosine content in DNA at earlier and later cell passages. The following facts were used as the basis of the method: (i) the rate of m5C loss from DNA remains approximately constant during cell divisions and it does not depend on the cell donor age; (ii) this rate is inversely proportional to the Hayflick Limit as well as to the life span of cell donor species; (iii) the period corresponded to loss of all m5C residues from the genome coincides with or somewhat exceeds the Hayflick Limit of normal cells. The prognosis of the Hayflick Limit has usually been found in good agreement with the experimental evidences for various human, hamster, and mouse cell lines.

Inheritance of androgen program of male-specific expression of unusual estrogen-binding protein by daughter hepatocytes at rat liver regeneration.

A possibility of inheritance of androgen and basic genetic programs at the level of unusual estrogen-binding protein (UEBP) by daughter hepatocytes was investigated. Liver regeneration after partial (2/3) hepatectomy or after selective poisoning of hepatocytes of the central zone of hepatic lobules with CCl4 in adult rats were used as models of total and zonal proliferation of hepatocytes, respectively. UEBP content and the pattern of its tissue expression in the course of liver regeneration were monitored by radioligand and immunocytochemical technique.

The structural features of beef heart mitochondrial creatine kinase.

Two forms of mitochondrial creatine kinase (Mi-CK) having Mr 320 kDa and 240 kDa as determined by gel-filtration on Sephacryl S-300 in 0.1 M Tris-HCl pH 7.4 were investigated.

Sorption of noble-metal ions on silica with chemically bonded nitrogen-containing ligands.

A study has been made of the sorption of Ir(IV), Rh(III), Pt(IV), Ru(IV), Os(VIII), Pd(II) and Au(III) from aqueous solutions by silica chemically modified with nitrogen-containing organic ligands, as a function of hydrochloric acid concentration, time of contact, concentration of the element and the ionic strength. Sorption of noble-metal ions at pH > 1 on a sorbent containing monoamine groups seems to be due to a complexation mechanism, and to an anion-exchange mechanism at pH < 1. With aminopropyl-silica 1000-fold concentration of Ir(IV) and Rh(III) from their 10(-8)-10(-7)M solutions was achieved and these metals were subsequently determined on the sorbent surface by X-ray fluorescence.

Constructing DNA by polymerase recombination.

Polymerase-mediated recombination based on DNA polymerase chain reactions (PCRs) has been used to carry out directed joining at a present point of two DNA fragments initially contained in a plasmid and a single-stranded synthetic DNA. The process includes copying of these fragments by PCR with generation of an overlapping homologous region. Such overlap of 12 base pairs in length was found to be sufficient to provide further DNA joining also by use of PCR.

Characterization of kinetoplast minicircle DNA in the lower trypanosomatid Crithidia oncopelti.

The kinetoplast DNA of the lower trypanosomatid Crithidia oncopelti contains minicircles of four major size classes. Attempts to clone these molecules revealed the unclonability of the full-length minicircles in pUC and M13 vectors. A few clones were obtained using a lambda insertion vector lambda XIII.

Effect of replacing the primary quinone by different species on the ultrafast photosynthetic electron transfer in bacterial reaction centres.

Using picosecond absorption spectroscopy it has been shown that in Rhodobacter sphaeroides reaction centres the substitution of the primary quinone acceptor (QA), ubiquinone-10, by other quinone species (with redox potentials higher or lower than that of ubiquinone-10) has essentially no modifying effect on the reaction centre protein. The molecular relaxation processes that accompany the localization and stabilization of a photo-excited electron on the intermediate acceptor, bacteriopheophytin (I), are not affected, although the subsequent transfer of the electron from I to QA is slowed down. Consequently, this leads to a lower quantum efficiency of high rate of direct I-----QA reaction is normally due to the specificity of the primary quinone species and its binding site in the reaction centre protein which provide optimum steric and chemical conditions for an effective interaction between I and QA.

Calcium-dependent phospholipid binding proteins associated with the membranes of rabbit skeletal muscle.

By using extraction in the presence of Ca2+ and Triton X-100 and then in the presence of EGTA without detergent, a set of Ca2+-dependent phospholipid binding proteins has been identified in the membranes of transverse tubules (T-tubules) and sarcoplasmic reticulum (SR), isolated from rabbit skeletal muscles. Longitudinal SR, junctional SR and T-tubule membranes yielded about 9, 14 and 3.3 micrograms of EGTA-soluble proteins per 1 mg of membrane protein, respectively.

Temperature dependence of cytochrome photooxidation and conformational dynamics of Chromatium reaction center complexes.

A temperature dependence of multiheme cytochrome c oxidation induced by a laser pulse was studied in photosynthetic reaction center preparations from Chromatium minutissimum. Absorbance changes and kinetic characteristics of the reaction were measured under redox conditions where one or all of the hemes of the cytochrome subunit are chemically reduced (E h =+300 mV or E h =-20 to -60 mV respectively). In the first case photooxidation is inhibited at temperatures lower than 190-200 K with the rate constant of the photooxidation reaction being practically independent on temperature over the range of 300 to 190 K (k=2.

Evidence for the presence of a new NAD+-dependent formate dehydrogenase in Pseudomonas sp. 101 cells grown on a molybdenum-containing medium.

The facultatively methylotrophic bacterium Pseudomonas sp. 101, grown on methanol in presence of molybdate, contains a new formate dehydrogenase (N-FDH) catalyzing NAD+-dependent oxidation of formate. The activity of this N-FDH could also be measured in presence of artificial electron acceptors, ferricyanide and 2,6-dichlorophenol indophenol.

Short-chain alkanols and the functional efficiency of the Ca pump in the sarcoplasmic reticulum of rabbit skeletal muscles.

The effect of 10 low molecular mass alkanols on the activity of Ca-ATPase (EC 3.6.1.