One-Year In Situ Incubation of Pyrite at the Deep Seafloor and Its Microbiological and Biogeochemical Characterizations.

In this study, we performed a year-long in situ incubation experiment on a common ferrous sulfide (Fe-S) mineral, pyrite, at the oxidative deep seafloor in the hydrothermal vent field in the Izu-Bonin arc, Japan, and characterized its microbiological and biogeochemical properties to understand the microbial alteration processes of the pyrite, focusing on Fe(II) oxidation. The microbial community analysis of the incubated pyrite showed that the domain Bacteria heavily dominated over Archaea compared with that of the ambient seawater, and Alphaproteobacteria and Gammaproteobacteria distinctively codominated at the class level. The mineralogical characterization by surface-sensitive Fe X-ray absorption near-edge structure (XANES) analysis revealed that specific Fe(III) hydroxides (schwertmannite and ferrihydrite) were locally formed at the pyrite surface as the pyrite alteration products. Based on the Fe(III) hydroxide species and proportion, we thermodynamically calculated the pH value at the pyrite surface to be pH 4.9 to 5.7, indicating that the acidic condition derived from pyrite alteration was locally formed at the surface against neutral ambient seawater. This acidic microenvironment at the pyrite surface might explain the distinct microbial communities found in our pyrite samples. Also, the acidity at the pyrite surface indicates that the abiotic Fe(II) oxidation rate was much limited at the pyrite surface kinetically, 3.9 × 103- to 1.6 × 105-fold lower than that in the ambient seawater. Moreover, nanoscale characterization of microbial biomolecules using carbon near-edge X-ray absorption fine-structure (NEXAFS) analysis showed that the sessile cells attached to pyrite excreted the acidic polysaccharide-rich extracellular polymeric substances at the pyrite surface, which can lead to the promotion of biogenic Fe(II) oxidation and pyrite alteration. IMPORTANCE Pyrite is one of the most common Fe-S minerals found in submarine hydrothermal environments. Previous studies demonstrated that the Fe-S mineral can be a suitable host for Fe(II)-oxidizing microbes in hydrothermal environments; however, the details of microbial Fe(II) oxidation processes with Fe-S mineral alteration are not well known. The spectroscopic and thermodynamic examination in the present study suggests that a moderately acidic pH condition was locally formed at the pyrite surface during pyrite alteration at the seafloor due to proton releases with Fe(II) and sulfidic S oxidations. Following previous studies, the abiotic Fe(II) oxidation rate significantly decreases with a decrease in pH, but the biotic (microbial) Fe(II) oxidation rate is not sensitive to the pH decrease. Thus, our findings clearly suggest that the pyrite surface is a unique microenvironment where abiotic Fe(II) oxidation is limited and biotic Fe(II) oxidation is more prominent than that in neutral ambient seawater.

[Transpupillary laser photocoagulation of ocular fundus: history, the present, and the future]. / Transpupillyarnaya lazernaya fotokoagulyatsiya tkanei glaznogo dna: proshloe, nastoyashchee i budushchee.

The present review covers the use of chorioretinal photocoagulation, which is now a popular treatment for many diseases of the ocular fundus. The review includes a detailed 50-year history of the technology with account to both Russian and foreign achievements. The current state of the field is shown through Russian and foreign literature data. A particular emphasis is placed on subthreshold, pattern, and navigated techniques. Breakthrough solutions, such as optoacoustic monitoring, that ensure high precision of the procedure, maximum saving of tissues, and high therapeutic effectiveness are described.

[Species-specific features of tocopherol content in carnivorous mammals during autumn period].

A comparative study of the major liposoluble antioxidant, vitamin E (α-tocopherol), content was conducted in carnivorous mammals (polar fox, silver fox, raccoon dog, mink, sable) during late autumn under natural lowering of temperature. The highest vitamin E content in liver and kidney was found in polar fox and raccoon dog, obviously due to seasonal metabolic changes and ecological specialization determining the accumulation of considerable amounts of tocopherol both in polar and hibernating species. To investigate the features of vitamin E accumulation, the tocopherol loading experiment was implemented on three species (polar fox, silver fox, mink). It was shown that polar fox, as compared to silverfox and mink, exhibits a higher ability to reserve vitamin E. The established differences in tocopherol content and distribution in different species should be considered as a genetically fixed reaction to the effect of environment underlain by metabolic differences in animals with different ecological specialization. The ability of tocopherol to accumulate in tissues and organs allows considering its essential role in stabilization of the antioxidant system and ensuring thereby a seasonal cold resistance.

[Light pollution, desynchronosis and aging: the state of problem and solutions].

The effect of different light conditions (constant illumination, light deprivation, the standard regime of lighting and natural for Northwest Russia lighting in different seasons of the annual cycle) on indicators of biological age and homeostasis, the development of age-related pathology, oncogenesis and longevity of rats was investigated. Exposure to constant light on the studied parameters was evaluated at different ages--antenatal, early and late postnatal period. The data about influences of substances and hormones of pineal gland on biomarkers of aging, homeostasis, spontaneous oncogenesis and longevity in experimental animals was obtained. It has been established that the light pollution and disturbance of photoperiod lead to desynchronosys and as a result to premature aging of the organism and age associated diseases. Ways of preventing accelerated aging were outlined.

[Double-component bacterial regulation systems as a target for searching new antimicrobial agents].

A review of the literature data concerning double-component bacterial regulation systems was given. The observed data concern: a) structural and functional organization based on the example of systems of the family OmpR (EnvZ/OmpR, PhoQ/PhoP), which regulate a number of processes providing adaptation to stress conditions in the environment and host body providing the virulence and biofilm formation, the cause of different human chronic infections; b) the genes and functions regulated by the double-components systems, based on the example of EnvZ/OmpR system, especially OmpR protein, and PhoQ/PhoP system. The possibilities for the searching of the double-component system protein inhibitors and their role in depressing pathogenic bacteria virulence were discussed.

[Plastid stromules as specific elements of the multipurpose endoplasmic reticulum].

It is supposed, that the compromise between all groups of researchers of stromules can be reached if to accept, that an external membrane of stromules together with an external membrane of initial plastid are the specific domain of endoplasmic reticulum. Such domain co-operates with other membranes of a cell by means of membrane contact sites with free permeability for small molecules (presumably to 1.5 KDa).

Angle-resolved XPS analysis and characterization of monolayer and multilayer silane films for DNA coupling to silica.

We measure silane density and Sulfo-EMCS cross-linker coupling efficiency on aminosilane films by high-resolution X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. We then characterize DNA immobilization and hybridization on these films by (32)P-radiometry. We find that the silane film structure controls the efficiency of the subsequent steps toward DNA hybridization. A self-limited silane monolayer produced from 3-aminopropyldimethylethoxysilane (APDMES) provides a silane surface density of ~3 nm(-2). Thin (1 h deposition) and thick (19 h deposition) multilayer films are generated from 3-aminopropyltriethoxysilane (APTES), resulting in surfaces with increased roughness compared to the APDMES monolayer. Increased silane surface density is estimated for the 19 h APTES film, due to a ∼32% increase in surface area compared to the APDMES monolayer. High cross-linker coupling efficiencies are measured for all three silane films. DNA immobilization densities are similar for the APDMES monolayer and 1 h APTES. However, the DNA immobilization density is double for the 19 h APTES, suggesting that increased surface area allows for a higher probe attachment. The APDMES monolayer has the lowest DNA target density and hybridization efficiency. This is attributed to the steric hindrance as the random packing limit is approached for DNA double helices (dsDNA, diameter ≥ 2 nm) on a plane. The heterogeneity and roughness of the APTES films reduce this steric hindrance and allow for tighter packing of DNA double helices, resulting in higher hybridization densities and efficiencies. The low steric hindrance of the thin, one to two layer APTES film provides the highest hybridization efficiency of nearly 88%, with 0.21 dsDNA/nm(2). The XPS data also reveal water on the cross-linker-treated surface that is implicated in device aging.

[Mobile ISCR elements: structure, functions, and role in the emergence, increasing and spreading of blocks of bacterial genes of multiple antibiotic resistance].

The recently discovered method of horizontal distribution of bacterial genes with atypical ISCR sequences is reviewed using an example of drug resistance genes. The adjacent DNA segment mobilization is provided by the transposition of such elements, including rolling circle replication, formation of autonomous nonreplicable circular structures, and homological recombination. The gene distribution capacity with the ISCR elements is more significant than the capacity of transposons and integrons, thereby providing formation of groups of mobile genes, including antibiotic-resistance genes of pathogenic bacteria. The structure and functions of the ISCR elements were discussed together with their similarity and dissimilarity with the group of IS91-similar elements and their role in the emergence of blocks of bacterial genes encoding of multiple antibiotic resistance and their contribution to evolution of bacterial and plasmid genes.

[Specific immunity and polymorphism of breeding plumage in pied flycatcher (Ficedula hypoleuca) males (Aves: passeriformes)].

The relationship between the type of melanin-based plumage coloration and the strength of experimentally induced immune response was studied using as an example a pied flycatcher population from the Moscow Region. The plumage of pied flycatcher males exhibits the full spectrum of transitions from contrasting black-and-white to cryptic brownish, the latter being very similar to the coloration of females. In spite of numerous studies, the nature of this polymorphism still remains vague. Unlike many other avian species with monocyclic breeding, a considerable fraction of pied flycatchers combines two energy-consuming productive processes, breeding and molt. During the main experimental treatment we activated the humoral immunity of free-living males in chick-rearing period by injection of nonpathogenic multigenic antigen (sheep red blood cells, SRBC) and estimated the strength of the immune responses after repeated captures in 6-8 days. In addition, after each capture we estimated the numbers of leucocytes (WBC), heterophil to lymphocyte ratios (H/L) and measured night time basal metabolic rates (BMR). Non-molting males of different color types showed the same immune responses. Among molting birds, the strength of the immune response was significantly higher in pale males (morphs 4-7 by Drost's scale) than in bright males with rich melanin-based coloration (morphs 2-3). This difference resulted from two opposite processes. During molting, pale males heightened the antibody titer after immunization, while bright males tended to reduce the strength of immune response. Possibly such an asymmetry in immunocompetence at the first stage of molt reflects the different life strategies of pied flycatcher males - conspicuous birds less commonly combine breeding with molt than cryptic ones.

[Laser cyclodestructive procedures in glaucoma treatment].

The history of development of cyclodestructive procedures is given, their advantages and disadvantages are discussed. Different techniques of laser use, relative and absolute contraindications to various laser cyclophotodestructive procedures are considered. Their potential complications and effecting mechanisms are discussed.

[Correction of secondary hyperlipidemia in children with diabetes].

At 25 children with insulin dependent diabetes mellitus (IDDM, Type I) in a decompensation stage was estimated efficiency of correction secondary hyperlipidemia. The basic group (n = 11) along with insulinotherapy and a lipotrophic preparation (methionine) accepted probiotic Bifiform Baby in a dose 0.5 g once a day within 10 days; the comparison group (n = 14) received insulin therapy and a lipotrophic preparation. Efficiency of treatment was estimated on dynamics of lipids in serum of blood: triglycerides (TG), the total cholesterol (TH), betalipoproteides (BLP). At patients of the basic group authentic decrease TG, TH, BLP was established; at patients of group of comparison--decrease TH and BLP. Advantage of therapy secondary hyperlipidemia at children with diabetic ketoacidosis with use of Bifiform Baby consists in the elimination of the main infringement of a metabolismus of lipids in the given disease--hypertriglyceridemia.

[Stromules-like protrusions of the membrane environment of plastids in the root cells].

The results of visualization of the stromules-like protrusions of the membrane environment of plastids in the root cells with the help of an electronic microscope are submitted. The cases of occurrence of long narrow protrusion of the external membrane with more short protrusion of the internal membrane of plastid environment inside it are discussed. The possible role of cytoskeleton and plastoskeleton in formation, accordingly, of "external" and "internal" protrusions is considered. The conclusion that the structure and functions of stromules in plant cells should be considered in unity with the structure and functions of the endoplasmic reticulum internal space is made.

[Intranuclear dynamics of chromosome 6 in nurse cells of Calliphora erythrocephala Mg. (Diptera: Calliphoridae)].

Intranuclear dynamics of chromosome 6 in nurse cell nuclei of Calliphora erythrocephala Mg. (Diptera: Calliphoridae) was studied. The 3D FISH method was used for the first time to study chromosome territories in highly polyploid nuclei whose chromosomes undergo morphological changes. A considerable change in the intranuclear location of chromosome 6 and a morphological alteration of the chromosome territory in the course of chromatin polytenization were revealed.

[Analysis of sex chromosome homologies in representatives of the family Calliphoridae].

The distribution of sequences homologous to the Calliphora erythrocephala Mg. sex chromosome was studied in Protophormia terranovae R-D and Lucilia sp. The chromatin structure was found to be similar in regions containing homologous DNA sequences.

[Analysis of the spatial organization of the XL chromosome attachment site in nurse cell nuclei of the malaria mosquito Anopheles atroparvus].

The spatial position of the site of XL chromosome attachment to the nuclear envelope of ovarian nurse cells relative to the oocyte has been analyzed in the malaria mosquito Anopheles atroparvus. The XL chromosome attachment sites in the oocyte-nurse cell system of this species have been demonstrated to be orderly arranged, with the attachment sites in two out of three nurse cells in the same layer identically oriented relative to the oocyte.

[Development of ovarioles and nurse cells cytoskeleton in Calliphora erythrocephala Mg. (Diptera; Calliphoridae)].

We have carried out the analysis of ovariole development and morphology in Calliphora erythrocephala Mg. (Diptera: Calliphoridae). It has been shown that several regions can be distinguished in C. erythrocephala germarium. In these regions cyst morphogenesis goes on stage by stage right up to the separation of formed egg chamber. There are fusomes of different degree of branching in germarium. Two egg chambers develop in C. erythrocephala vitellarium. We have researched distribution of actin filaments and ring canals formation in the nurse cells of C. erythrocephala. Diameter of ring canals increases from 1.5 microm in germarium zone to 14.7 microm at 3 and 4 stadies oogenesis. We suggest the scheme that illustrates irregular stretching of actin rollers which are formed during middle and late oogenesis around the ring canals joining proximal, sharply increased in size nurse cells with neighboring nurse cells.

[Results of clinical trials on reactogenicity, safety, and immunogenicity of influenza allantoic intranasal live vaccine "Ultragrivac" (type A/H5N2)].

Results of phase II of a clinical trial of the influenza allantoic intranasal live vaccine "Ultragrivac" (type A/H5N2) are presented. The vaccine was developed based on strain /17/Duck/Potsdam/86/92 H5N2 [17/H5] - reassortant of two viruses, /Leningrad/134/17/57 (H2N2) and /Duck/Potsdam/1402-86 (H5N2), obtained from the Virology Department, St. Petersburg Institute of Experimental Medicine.Two schemes of immunization (with revaccination on days 10 and 21) were used. Evaluation of vaccine immunogenicity included determination of local, cellular and humoral immunity. A significant rise in the level of secretory IgA in the nasal cavity of vaccinated volunteers (with revaccination on days 10 and 21) was documented after application of the vaccine. The postvaccination humoral immune response was estimated from the level of significant (4-fold and more) antibody seroconversions, geometric mean titers of antibodies to two strains of influenza virus /17/Duck/Potsdam/86/92 H5N2 [17/H5] and /Chicken/Suzdalka/Nov-11/2005 (H5N1), and their incremental rate. Results of measurement of antibody titers in hemagglutination-inhibition assay are presented, with two antigens being used to analyse all serum samples from volunteers twice vaccinated with influenza vaccine "Ultragrivac" at 10 and 21 day intervals. Result of phase II of this clinical study show that influenza allantoic intranasal live vaccine "Ultragrivac" is nonreactogenic and safe for both vaccinated and surrounding individuals. Moreover, it is sufficiently immunogenic with respect not only to homologous virus A(H5N2) but also to the A(H5N1) strain.

[Alternative of laser treatment optimization in retinoschisis].

In this study a new original technique is proposed for treatment of II-III retinoschisis using diode laser Milon Lachta (Saint-Petersburg). Laser radiation parameters were wave length 0,83 microm, energy 350-850 m W, time 0,2-0,3 s, spot diameter 150-200 microm. Original technique of gradual progressive laser coagulation was performed in 72 patients with II-I1 retinoschisis using diode laser. This treatment allowed to preserve macular function to the maximum.

[Efficiency of laser coagulation in the treatment of rhegmatogenous retinal detachment].

A hundred and seventeen (143 eyes) patients with different types of retinal detachment were examined. The patients were treated by laser coagulation on a LAHTA device (Milon). The clinical findings indicated the efficiency of retinal laser coagulation as an independent treatment for retinal rhegmatogenous detachment and indications for laser coagulation were defined in the following types of retinal detachment: subclinical local retinal detachment; fresh mobile retinal detachment (Stages A and B); non-mobile retinal detachment occupying not more than one quadrant, and partially self-circumscribed retinal detachment (Stages B and C1) taking up the lower quadrants. The benefits of this method are noninvasiveness and high functional results, which enables laser coagulation to be regarded as an independent effective treatment for the above types of retinal detachment.

[The influences of geroprotectors on age-related changes of antioxidant system in rats liver under different light condition].

The influences of different light condition, melatonin and epithalon on liver antioxidant system in 6-, 12-, 18- and 24-month-old rats of both sexes were studied. The activities of antioxidant enzymes as well as concentration of tocopherol demonstrate high stability. The maximal number of significant changes in antioxidant system parameters was found under continuous light exposure. Light condition, sex and preparation modulated age-related changes of antioxidant system.