Physiological-biochemical aspects of omission of the spawning period in the Barents Sea cod Gadus morhua

Using histological and biochemical methods, ovaries of the Barents Sea cod Gadus morhua were studied in different physiological states (immature fish, normal maturation, omission of spawning). Among the fish missing spawning, two categories are identified: without signs of occyte maturation and with massive resorption of maturing oocytes. The maximal activity of lysosomal and cytoplasmic proteolytic enzymes was revealed in the fish ovaries with histological signs of massive oocyte resorption. In the ovaries of maturing fish the highest concentrations of water-soluble proteins was found. The molecular-mass protein composition and the fraction responsible for the cytosol proteinase activity were determined by electrophoresis and high-performance liquid chromatography (HPLC). The obtained results allow some suggestions to be made about mechanisms of degradation of cellular proteins and functions of proteinases in various physiological states of the cod gonads.     

Role of L-type Ca channels in Ca2+ accumulation and changes in distribution of myosin heavy chain and SERCA isoforms in rat M. soleus under gravitational unloading

It is known that hindlimb unloading brings about the intracellular Ca2+ accumulation and MyHC slow-to-fast shift in m.soleus. SERCA (sarcoendoplasmatic reticulum Ca ATPase) function as a Ca pump to uptake to sarcoendoplasmatic reticulum after skeletal muscle contraction, and can modulate intracellular resting Ca level. The study was aimed at investigation of the role of intracellular Ca2+ level for MyHC and SERCA isoforms transformation in m.soleus under hindlimb unloading. To determine role of intracellular Ca we administrated nifedipin--specific blocker of L-type calcium channel in myofibers. We hypothesized that decrease of intracellular calcium level prevented-NFATc1 nuclear translocation and MyHC slow-to-fast transformation. 42 male Wistar rats (180-200 g) were divided in 3 groups: cage control (C, n = 14), 14 days HU (HU, n = 14), 14 days HU with 7 mg/kg/day of nifedipin administration with water (HUN, n = 14). The study has shown that increase of intracellular Ca2+ level under HU leads to MHC slow-to-fast shift via activation of calcineurin-NFATc1 signaling pathway. Percentage of muscle fibers with SERCA I increased under hindlimb unloading, being dependent of intracellular calcium level, percentage of muscle fibers with SERCA II decreased under hindlimb unloading but did not depend on calcium. We suppose that nifedipin administration decreases intracellular Ca level, prevents MHC slow-to-fast shift via prevention of NFATcl accumulation in nuclear extract of m.soleus, and prevent increase of SERCAI expression. The work was supported by grants RFBR N05-04-49255a, 04-04-49044, 05-04-08200-ofi-a, contract with Federal Agency for Science and Iinnovation N02.467.11.3005, and Presidium of RAS program "Basic sciences for medicine".     

Effect of deafferentation on the size and myosin phenotype of muscle fibers during stretching of rat m. soleus and gravitational unloading

The study was purposed to evaluate the contribution of the reflectory and local components during the chronic stretch of the postural muscle to the attenuation of the unloading-induced fiber size reduction and changes in the myosin heavy chain (MHC) profile. The surgical unilateral deafferentation (dorsal rhizotomy) was used. It was shown that unilateral deafferentation didn't influence on the amelioration of unloading-induced fiber size reduction in chronically stretched soleus muscle. Thus, the results obtained in the present study don't confirm the hypothesis, supposing the predominant contribution of the muscle afferent activation to the attenuation of unloading-induced fiber atrophy. Deafferentation of unloaded as well as control rats leads to the increase of the percentage of fibers expressing slow MYC isoforms.     

A structural and thermodynamic analysis of novatrone and flavin mononucleotide heteroassociation in aqueous solution by 1H NMR spectroscopy

A heteroassociation of antitumor antibiotic novatrone (NOV) and flavin mononucleotide (FMN) in aqueous solution was studied by one- and two-dimentional 1H NMR spectroscopy (500 MHz) to elucidate the molecular mechanism of the possible combined action of the antibiotic and vitamin. The equilibrium reaction constants, induced proton chemical shifts, and the thermodynamic parameters (deltaH and deltaS) of the NOV and FMN heteroassociation were determined from the concentration and temperature dependences of proton chemical shifts of the aromatic molecules. The most favorable structure of the 1 : 1 NOV-FMN complex was determined by both the method of molecular mechanics (X-PLOR software) and the induced proton chemical shifts of the molecules. An analysis of the results suggests that the NOV-FMN intermolecular complexes are mainly stabilized by stacking interactions of their aromatic chromophores. An additional stabilization is possible due to intermolecular hydrogen bonds. It was concluded that the aromatic molecules of vitamins, in particular, FMN, can form energetically favorable heterocomplexes with aromatic antitumor antibiotics in aqueous solutions, which could result in a modulation of their medical and biological action.     

Characterization of oligonucleotides with LNA-monomers for PCR detection of point mutations in <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> genome

Point mutations associated with isoniazid resistance in Mycobacterium tuberculosis (MTB) have been analyzed in codon 315 of the katG gene by conventional polymerase chain reaction (PCR) using primers containing locked nucleic acid (LNA) modified nucleotides. Purity and structure of primers containing 5 LNA monomers of 17 nucleotides in length were characterized by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and a 17-mer duplex formed by two complementary oligonucleotides was characterized by the method of thermal denaturation. The duplex containing five LNA monomers per each strand was characterized by a higher melting temperature than it was expected using extrapolation of theoretical calculation for nucleotide modification of one strand of the duplex. Detection of any of six possible mutations in katG codon 315 (i.e. discrimination between sensitive and resistant MTB) requires just one PCR employing a set of two primers with one LNA-modified primer; this is an important advantage of oligonucleotides containing LNA over unmodified nucleotides: employment of multiplex PCR would require up to 12 primers. Problems of control of oligonucleotide modification by LNA monomers are discussed.     

Prebreeding selection of rice with colored pericarp based on genotyping <Emphasis Type="Italic">Rc</Emphasis> and <Emphasis Type="Italic">Pb</Emphasis> genes

The research was aimed at developing prebreeding resources of Kazakhstan rice varieties with colored pericarp for breeding. During the study, hybrid analysis of inheritance of the trait “colored pericarp” in breeding material used for the work was performed. Rice genotypes with colored pericarp, as well as white rice varieties possessing important breeding traits and maturing under conditions of the republic, were selected from the collection of the Institute of Plant Biology and Biotechnology, Republic of Kazakhstan. Identification of allelic status of Rc (red pericarp) and Pb (anthocyanin pericarp) genes was performed for selected samples using the PCR method. When selecting parental forms for crossing, foreign rice varieties with colored pericarp (Rubin, Mavr, Black rice, etc.) were used as recipient forms. As donors, we used local white rice varieties of Kazakhstan breeding adapted to the soil and climate conditions of rice growing regions (Madina, Marzhan, Bakanasskiy, PakLi) as well as foreign varieties. The ability to set hybrid caryopses and the percentage of sterility were determined in obtained F1 rice hybrids. As a result, the most promising prebreeding material was selected, which will be used for breeding Kazakhstan rice varieties with colored pericarp.     

Chemotactic effect of urokinase plasminogen activator: a major role for mechanisms independent of its proteolytic or growth factor domains.

Urokinase type plasminogen activator (uPA) converts plasminogen to plasmin and is highly chemotactic for many cell types. We examined, using recombinant wild type and mutated forms of uPA, the extent to which its proteolytic properties, its growth-like domain (GFD) and/or interactions with the specific receptor (uPAR) contribute to the chemotactic activity towards vascular smooth muscle cells (SMC). Recombinant wild type uPA (r-uPA) stimulated cell migration nearly 5.8-fold, inactive r-uPA, with a mutation in the catalitic domain (r-uPA(H/Q)), 3-fold, uPA without growth factor like domain (r-uPA(GFD )), 2.6-fold, and a form containing both mutations (r-uPA(H/Q, GFD ), 3.3-fold. All recombinant forms of uPA, wild type and those with mutations were equally and highly effective (IC50 approximately 20 nM) in displacing 125I-r-uPA bound to SMC. These results indicate that additional mechanisms, not dependent on uPA's proteolytic activity or the binding ability of its GFD to uPAR, are the major contributors to its chemotactic action on SMC.     

Epidemiological characteristics of meningococcal infection in a number of territories of the RSFSR (1969-1984)

In this work the dynamics and morbidity level in respect of meningococcal infection at 11 territories of the RSFSR at the period of 1969-1984 are analyzed. The study covered altogether 16 cities and 211 districts. The role of big cities as the sources of infection spreading into rural areas and further "fixation" of this infection mainly in regions with a population of 60,000 and more had been established. The data on meningococcal morbidity and carriership among different age groups are presented. The study has shown a pronounced increase in the incidence rate of meningococcal infection among children aged up to 2 years, as well as an increase in the proportion of these children among patients with meningococcal infection in recent years.