Transformation Processes of Fauna of the Abkhazian Coast in the Caucasus and Possible Causes and Mechanisms

This article discusses the species wealth and ecological and faunogenetic structure of nesting avifauna at three different sites on the Black Sea coast in Abkhazia in the vicinity of the Pitsunda–Mussera Reserve (the Pitsunda Lowland, the Mussera Hills, and the Gudauta Plain) versus the avifauna of the Colchis Lowland in Georgia and the Imereti Lowland in the lower reaches of the Mzymta River in Russia. This comparison has revealed the key biotic, abiotic, and anthropogenic factors that determine the formation of regional faunas. The comparative analysis of the avifauna of the Abkhazian coast in four time spans (the beginning of the 20th century, the middle of the 20th century, the 1960s–1980s, and the beginning of the 21st century) has determined the basic trends of its transformation, the rate of changes being observed, and the sources of the formation of the fauna of separate bird species and the causes of their disappearance. The data obtained were used for predicting the development of the avifauna of Colchis landscapes in Abkhazia for the next 100 years.     

Memorial museum to Academician O.V. Palladin (on the 25th anniversary of the foundation

In the article the short information about A.V. Palladin Memorial Museum, displaying some documentary materials on the life, scientific, scientific-administrative and enlightenment activity of the founder of the Institute of Biochemistry and Ukrainian Biochemical school, President of UkSSR Academy of Sciences (1946-1962), outstanding scientist and public figure, Academician Alexander Vladimirovich Palladin (1885-1972). The Museum created according to the Resolution of the UkSSR Soviet of Ministers due to the efforts of the Institute personnel, is officially considered as an affiliate of the State Historical Museum of Kiev and acquired a wide-spread reputation as a center of propagation and study of the history of Ukraine biochemical science, its achievements, contribution of the native scientists into the world treasury of the life sciences.     

Peroxynitrite inhibits relaxation and induces pulmonary artery muscle contraction in the newborn rat

Nitric oxide (NO) reacts with superoxide anion to form the peroxynitrite anion (ONOO-), a molecule with pulmonary vasodilator properties in the adult rat. The purpose of this study was to compare the effects of ONOO- on intrapulmonary arteries from the newborn (days 4-7), juvenile (day 14), and adult rat. Following thromboxane A2 (TXA2) analogue (U46619) prestimulation, newborn vessels were more sensitive to ONOO- -induced muscle contraction, compared to both the juvenile and the adult vessels. Peroxynitrite-induced contraction in newborn vessels was abrogated by ibuprofen, an endothelin B-receptor blocker (A-192621), or a rho-kinase-specific inhibitor (Y27632) (all p < 0.01). Following KCl stimulation and TXA2 receptor blockade, ONOO- induced NO-dependent muscle relaxation in newborn vessels via stimulation of the endothelial and inducible nitric oxide synthases. However, in the presence of ONOO-, the pulmonary artery relaxation response to endothelium-dependent stimulation was significantly reduced (p < 0.01). Finally, newborn but not adult pulmonary arteries exposed to ONOO- showed a 10-fold increase in 8-isoprostane production, a possible mediator of ONOO- -induced contraction. We conclude that exposure to ONOO- results in a unique response in newborn intrapulmonary arteries characterized by increased 8-isoprostane generation, which we believe is responsible for its vasoconstrictor effect. This unique response potentially renders the newborn more susceptible to ONOO- -induced pulmonary hypertension than older animals.     

A new recombinant <Emphasis Type="Italic">endo-</Emphasis>1,3-β-<Emphasis Type="SmallCaps">d</Emphasis>-glucanase from the marine bacterium <Emphasis Type="Italic">Formosa algae</Emphasis> KMM 3553: enzyme characteristics and transglycosylation products analysis

A specific endo-1,3-β-d-glucanase (GFA) gene was found in genome of marine bacterium Formosa algae KMM 3553. For today this is the only characterized endo-1,3-β-d-glucanase (EC 3.2.1.39) in Formosa genus and the only bacterial EC 3.2.1.39 GH16 endo-1,3-β-d-glucanase with described transglycosylation activity. It was expressed in E. coli and isolated in homogeneous state. Investigating the products of polysaccharides digestion with GFA allowed to establish it’s substrate specificity and classify this enzyme as glucan endo-1,3-β-d-glucosidase (EC 3.2.1.39). The amino-acid sequence of GFA consists of 556 residues and shows sequence similarity of 45–85% to β-1,3-glucanases of bacteria belonging to the CAZy 16th structural family of glycoside hydrolases GH16. Enzyme has molecular weight 61 kDa, exhibits maximum of catalytic activity at 45?°C, pH 5.5. Half-life period at 45 °С is 20 min, complete inactivation happens at 55?°C within 10 min. K_m for hydrolysis of laminarin is 0.388 mM. GFA glucanase from marine bacteria F. algae is one of rare enzymes capable to catalyze reactions of transglycosylation. It catalyzed transfer of glyconic part of substrate molecule on methyl-β-d-xylopyranoside, glycerol and methyl-α-d-glucopyranoside. The enzyme can be used in structure determination of β-1,3-glucans (or mixed 1,3;1,4- and 1,3;1,6-β-d-glucans) and enzymatic synthesis of new carbohydrate-containing compounds.     

Quorum sensing and communication in bacteria

Bacteria are able “to sense” an increase in the cell population density and to respond to it by the induction of special sets of genes. This type of regulation, called Quorum Sensing (QS), includes the production and excretion of low-molecular-weight signaling molecules (autoinducers, AI), which diffuse readily through the cell wall, from cells into the medium. As the bacterial population reaches the critical level of density, the concentration of these signaling molecules in the medium increases as a function of population density. On reaching the critical threshold concentration, AIs bind to specific receptor regulatory proteins, which induce the expression of target genes. By means of AIs, bacteria accomplish the communication that is the transmission of information between bacteria belonging to the same or different species, genera, and even families: the signaling molecules of some bacteria affect the receptors of others causing a coordinated reply of cells of the bacterial population. Bacteria of different taxonomic groups use the QS systems in regulation of a broad range of physiological activities. These processes include virulence, symbiosis, conjugation, biofilm formation, bioluminescence, synthesis of enzymes, antibiotic substances, etc. Here we review different QS systems of bacteria, the role of QS in bacterial communication, and some applied aspects of QS regulation application.     

Biochemical aspects of the action of local anesthetics

Notions on the molecular mechanisms of anesthesia are presented. The chemical characteristics are given for main representatives of certain groups of local anesthetics with peculiarities of their membrane-tropic action mentioned. The effect of local anesthetics on the synaptic transmission, membrane enzymes, ion transport through the cell membranes is considered simultaneously with the anesthesia phenomenon on the basis of the data available in literature and results of the authors' investigations.     

Blood-brain barrier to hydrogen ion during acute metabolic acidosis in piglets

The present study investigates the integrity of the blood-brain barrier to H+ or HCO3- during acute plasma acidosis in 35 newborn piglets anesthetized with pentobarbital sodium. Cerebrospinal fluid acid-base balance, cerebral blood flow (CBF), and cerebral oxygenation were measured after infusion of HCl (0.6 N, 0.191-0.388 ml/min) for a period of 1 h at a constant arterial PCO2 of 35-40 Torr. HCl infusion resulted in decreased arterial pH from 7.38 +/- 0.01 to 7.00 +/- 0.02 (P less than 0.01). CBF measured by the tracer microsphere technique was decreased by 12% from 69 +/- 6 to 61 +/- 4 ml.min-1.100 g-1 (P less than 0.05). Infusion of 0.6 N NaCl as a hypertonic control had no effect on CBF. Cerebral metabolic rate for O2 and O2 extraction was not significantly changed from control (3.83 +/- 0.20 ml.min-1.100 g-1 and 5.7 +/- 0.6 ml/100 ml, respectively) during acid infusion. Cerebral venous PO2 was increased from 41.6 +/- 2.1 to 53.8 +/- 4.0 Torr by HCl infusion (P less than 0.02) associated with a shift in O2-hemoglobin affinity of blood in vivo from 38 +/- 2 to 50 +/- 1 Torr. Cisternal cerebrospinal fluid pH decreased from 7.336 +/- 0.014 to 7.226 +/- 0.027 (P less than 0.005), but cerebrospinal fluid HCO3- concentration was not changed from control (25.4 +/- 1.0 meq/l). These data suggest that there is a functional blood-brain barrier in newborn piglets, that is relatively impermeable to HCO3- or H+ and maintains cerebral perivascular pH constant in the face of acute severe arterial acidosis. (ABSTRACT TRUNCATED AT 250 WORDS)     

Soluble guanylate cyclase-dependent relaxation is reduced in the adult rat bronchial smooth muscle

Cyclic nucleotides are relaxants of the airway smooth muscle, yet most of the available data were obtained in adult animals. The expression and activity of cyclases have been reported to be developmentally regulated in the lung, and little is known about the age-related changes in their bronchial muscle relaxation potential. We evaluated and compared the newborn and adult rat bronchial smooth muscle response to cyclic AMP- and GMP-dependent agonists in isometric mounted bronchial rings. In acetylcholine-precontracted bronchial muscle, the relaxant response to the cAMP agonist forskolin was not age dependent, but the relaxant response to the nitric oxide (NO) donor sodium nitroprusside (SNP) was significantly greater (P<0.01) in the newborn. To further evaluate the cGMP pathway, we stimulated the soluble guanylate cyclase (sGC) with the specific agonists BAY 41-2272 and YC-1. In keeping with the SNP dose-response curves, the sGC agonists significantly relaxed the newborn, but not the adult bronchial muscle. Protein expression of the sGC alpha1- and beta1-subunits were significantly lower (P<0.01) in the adult compared with the newborn bronchial tissue. Consistent with these results, the NO-stimulated sGC activity was significantly greater in the newborn compared with the adult (P<0.01). In conclusion, the bronchial smooth muscle cGMP-, but not cAMP-dependent, relaxant response is developmentally regulated and significantly reduced in the adult rat.