Left-ventricular heart aneurism as a new source of resident cardiac stem cells

In the past few years, it has been established that the heart contains a reservoir of stem and progenitor cells. These cells are able to differentiate in cardiomyogenic, endothelial, and smooth muscle lineages in vitro and in vivo and, following injection into an infarcted myocardium, these cells prevent the remodeling of the left ventricle and improve cardiac function. The aim of the present study was the immunophenotypic characterization of resident stem cells in the tissue of a chronic left aneurism, an analysis of their localization, and distribution in various aneurism areas.     

Distribution of iron- and manganese-oxidizing bacteria in the bottom sediments of Lake Baikal

The specific features of the distribution, abundance, and taxonomic diversity of bacteria oxidizing iron and manganese in the bottom sediments sampled from different areas of Lake Baikal are studied. These bacteria are widespread in Baikal bottom sediments. Cultivated iron- and manganese-oxidizing microorganisms are ascribed to six genera: Metallogenium, Leptothrix, Siderocapsa, Naumaniella, Bacillus, and Pseudomonas. The surface layers of the ground and the border between oxidized and reduced sediments serve as ecological niches for iron- and manganese-oxidizing microorganisms. Redox conditions of the environment and the availability of dissolved forms of iron and manganese, as well as of organic matter, which are controlled by the conditions of sedimentation in the lake, are the main factors affecting the abundance and distribution of iron bacteria.     

The functional morphology of erythrocytes of the black scorpion fish <Emphasis Type="Italic">Scorpaena porcus</Emphasis> (Linnaeus, 1758) (scorpaeniformes: scorpaenidae) during hypoxia

The influence of hypoxia on the morphological characteristics of circulating erythrocytes of the scorpion fish Scorpaena porcus (Linnaeus, 1758) has been investigated in an in vivo experiment. Under a 4-h adaptation of the fish to the conditions of ranked hypoxia their erythrocytes demonstrated a number of consecutive reactions. The volume and the surface area of the red blood cells was reduced by 4–5% (p < 0.001) at an oxygen concentration of 2.6 mg/L (30% saturation of water with oxygen) and increased by 4% (p < 0.001) at a concentration of 1.3 mg/L (15% saturation), relative to the control values (normoxia: 7–8 mg/L). The observed reaction of erythrocytes coincided quantitatively and qualitatively (the order of events) with the results of the experiments we performed previously in vitro. Our study has shown that the physiology of the black scorpion fish is tolerant to hypoxia and allows autonomous functioning of red blood cells under conditions of oxygen deficit.     

Synthesis and antimicrobial activity of quinopimaric and maleopimaric acids

A number of nitrogen-, bromine-, and sulfur-containing derivatives of diene adducts of levopimaric acid have been synthesized. The testing of the compounds on Staphylococcus aureus and Klebsiella pneumoniae bacteria has shown that the compounds possess a weak antimicrobial activity.     

Hydrogen sulfide and cerebral microvascular tone in newborn pigs

Hydrogen sulfide (H2S) is a gaseous signaling molecule that appears to be involved in numerous biological processes, including regulation of blood pressure and vascular tone. The present study is designed to address the hypothesis that H2S is a functionally significant, endogenous dilator in the newborn cerebrovascular circulation. In vivo experiments were conducted using newborn pigs with surgically implanted, closed, cranial windows. Topical application of H2S concentration-dependently (10(-6) to 2×10(-4) M) dilated pial arterioles. This dilation was blocked by glibenclamide (10(-6) M). L-cysteine, the substrate of the H2S-producing enzymes cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS), also dilated pial arterioles. The dilation to L-cysteine was blocked by the CSE inhibitor d,l-propargylglycine (PPG, 10 mM) but was unaffected by the CBS inhibitor amino-oxyacetate (AOA, 1 mM). Western blots detected CSE, but not CBS, in cerebral microvessels, whereas CBS is detected in brain parenchyma. Immunohistological CSE expression is predominantly vascular while CBS is expressed mainly in neurons and astrocytes. L-cysteine (5 mM) increased H2S concentration in cerebrospinal fluid (CSF), measured by GC-MS, from 561±205 to 2,783±818 nM before but not during treatment with PPG (1,030±70 to 622±78 nM). Dilation to hypercapnia was inhibited by PPG but not AOA. Hypercapnia increased CSF H2S concentration from 763±243 to 4,337±1789 nM before but not during PPG treatment (357±178 vs. 425±217 nM). These data show that H2S is a dilator of the newborn cerebral circulation and that endogenous CSE can produce sufficient H2S to decrease vascular tone. H2S appears to be a physiologically significant dilator in the cerebral circulation.     

Nox4 NADPH oxidase-derived reactive oxygen species, via endogenous carbon monoxide, promote survival of brain endothelial cells during TNF-α-induced apoptosis

We investigated the role of reactive oxygen species (ROS) in promoting cell survival during oxidative stress induced by the inflammatory mediator tumor necrosis factor-α (TNF-α) in cerebral microvascular endothelial cells (CMVEC) from newborn piglets. Nox4 is the major isoform of NADPH oxidase responsible for TNF-α-induced oxidative stress and apoptosis in CMVEC. We present novel data that Nox4 NADPH oxidase-derived ROS also initiate a cell survival mechanism by increasing production of a gaseous antioxidant mediator carbon monoxide (CO) by constitutive heme oxygenase-2 (HO-2). TNF-α rapidly enhanced endogenous CO production in a superoxide- and NADPH oxidase-dependent manner in CMVEC with innate, but not with small interfering RNA (siRNA)-downregulated Nox4 activity. CORM-A1, a CO-releasing compound, inhibited Nox4-mediated ROS production and enhanced cell survival in TNF-α-challenged CMVEC. The ROS-induced CO-mediated survival mechanism requires functional interactions between the protein kinase B/Akt and extracellular signal-related kinase (ERK)/p38 MAPK signaling pathways activated by TNF-α. In Akt siRNA-transfected CMVEC and in cells with pharmacologically inhibited Akt, Erk1/2, and p38 mitogen-activated protein kinase (MAPK) activities, CORM-A1 was no longer capable of blocking Nox4 activation and apoptosis caused by TNF-α. Overall, Nox4 NADPH oxidase-derived ROS initiate both death and survival pathways in TNF-α-challenged CMVEC. The ROS-dependent cell survival pathway is mediated by an endogenous antioxidant CO, which inhibits Nox4 activation via a mechanism that includes Akt, ERK1/2, and p38 MAPK signaling pathways. The ability of CO to inhibit TNF-α-induced ERK1/2 and p38 MAPK activities in an Akt-dependent manner appears to be the key element in ROS-dependent survival of endothelial cells during TNF-α-mediated brain inflammatory disease.     

Ca2+-protease--an enzyme of the metabolism of cytoskeletal proteins in the olfactory membrane of vertebrates

Two forms of Ca(++)-activated protease (calpain I and calpain II) associated with an endogenous inhibitor (calpastatin) were detected in a cytosolic fraction of the olfactory tissue of vertebrates (pig, rat). Using ion exchange chromatography on DEAE-cellulose column, calpain I is divided into 2 peaks (eluting by 0.07-0.15 and 0.22-0.25 M NaCl), and calpain II is eluted by 0.35-0.40 M NaCl. The calpain activity was detected in fractions eluted by 0.1-0.17 M NaCl. The Ca(++)-activated protease was demonstrated also in a fraction of cytoskeleton of olfactory tissue insoluble in a 1% solution of Triton X-100. The activity can be detected by Ca(++)-dependent destruction of exogenous substrate (casein), and by Ca(++)-dependent degradation of cytoskeletal endogenous proteins (16, 18 and 20 kDa), of which one may be calmodulin.     

Changes in the complex conditioned reflex activity of rat pups under the influence of penta-peptide]

Influence of YFRKD, modified fragment of interferon-alpha, on the formation of two-links system of feed-procuring conditioned reflexes was studied in rats in ontogenesis. The experiments have shown that YFRKD impedes both current learning and use of previous experience. The process of synthesis of two reflexes in united complicated functional complex is disturbed.     

The quantitative analysis of polymorphism on human chromosomes 1, 9, 16, and Y

This study was made to establish a stable quantitative characteristic of C segments on chromosomes 1, 9, 16, and Y in an individual karyotype that was reproducible in successive experiments. The C segment of these chromosomes were measured in successive cultures of cells from three males and the C segments of chromosomes 1, 9, and 16 in cells from three pairs of female monozygotic twins were measured. The results show that the absolute lengths of C segments tend to vary considerably with the cell samples analyzed, while the relative length, i.e., the length of a single C segment as a percentage of the total length of all C segments of the chromosomes being studied, is more stable and can be used for individual characteristics.     

Antagonistic activity of actinomycetes of Lake Baikal

It was demonstrated that the actinomycetes of Lake Baikal are strong antagonists of other microorganisms. Representatives of the genera Streptomyces and Micromonospora inhibit the growth of bacteria isolated from the lake, as well as of antibiotic-resistant microorganisms causing various human diseases. Baikal actinomycetes display a wide range of antagonistic activity and are potential producers of new biologically active substances.