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The globally abundant, uncultured unicellular cyanobacterium UCYN- A was recently discovered living in association with a eukaryotic cell closely related to a prymnesiophyte. Here, we established a double CAtalysed Reporter Deposition-Fluorescence In Situ Hybridization ( CARD- FISH) approach to identify both partners and provided quantitative information on their distribution and abundance across distinct water masses along a transect in the North Atlantic Ocean. The N2 fixation activity coincided with the detection of UCYN- A cells and was only observed in oligotrophic (< 0.067 [ABSTRACT FROM AUTHOR]

Highlights: [•] Single-crystal EPR spectra allow a detailed characterization of the center in quartz. [•] Three distinct A(17O) provide the first direct proof of an oxygen vacancy for E′ centers. [•] The single-oxygen-vacancy V(O)+ model cannot account for the new A(17O) data. [•] The tri-vacancy with an Al impurity model V(SiO2)Al reproduces all EPR hyperfine data. [ABSTRACT FROM AUTHOR]

The crystal structures of two elbaites from the Paraiba deposit with copper contents of 3.51 and 1.61 wt% CuO [a = 15.881(1), 15.840(3); c = 7.112(1), 7.1028(9), respectively], as well as a synthetic Cu-bearing olenite with a CuO content of 8.39 wt% [a = 15.840(4), c = 7.091(1)] have been refined to R-indices of 2.2, 3.1, and 4.1% using X-ray single-crystal diffraction. On the basis of original and published data (for six structures) the crystal-chemical relationships of copper-bearing tourmalines has been analyzed. It is shown that copper cations and cations of other 3d elements (Mn, Zn, Fe) occupy almost exclusively the Y site. Such an ordered distribution results in a change of the size of the Y-octahedra. There is an inverse correlation between the content of 3d elements (mainly Cu2+ cations) and Al3+-cations in the Y-octahedron and also between the value of and the content of Al3+ cations in the Y site. The direct correlation between values of -distance in the structures of Cu-bearing elbaites and the parameters (a, c) of the unit cell have been found. Distortions of polyhedra in the structures of Cu-bearing elbaites are similar, and significantly higher than those present in the structure of the synthetic Cu-bearing olenite. [ABSTRACT FROM AUTHOR]

Abstract: Nitrogen (N2) fixation is a globally important process often mediated by diazotrophic cyanobacteria in the open ocean. In 2010, seawater was collected near Cape Verde to identify and measure N2 and carbon (C) fixation by unicellular diazotrophic cyanobacteria. The nifH gene abundance (104–106 nifH L−1) and nifH gene transcript abundance (102–104 cDNA nifH L−1) for two unicellular groups, UCYN-A and UCYN-B, were detected. UCYN-A was also identified and quantified (104–105 cellsL−1) by new probes (UCYN-A732 and UCYN-A159) using Catalyzed Reporter Deposition-Fluorescence In Situ Hybridization (CARD-FISH) assays. The UCYN-A were observed as free cells or attached to a larger unidentified eukaryotic cell. A Halogen In Situ Hybridization-Secondary Ion Mass Spectrometry (HISH-SIMS) assay using the UCYN-A732 probe was applied on samples previously incubated with 13C-bicarbonate and 15N2. Free UCYN-A cells were enriched in both 13C and 15N and estimated C and N2 fixation rates for UCYN-A were lower compared to co-occurring unicellular cyanobacteria cells similar in size (3.1–5.6μm) and pigmentation to diazotroph Crocosphaera watsonii. Here, we identify and quantify two common co-occurring unicellular groups and measure their cellular activities by nanoSIMS. [Copyright &y& Elsevier]

Synthetic stishovite before and after electron- and γ-ray irradiation has been investigated by single-crystal electron paramagnetic resonance (EPR) spectroscopy for the first time. Room-temperature single-crystal EPR spectra of as-is stishovite reveal two high-spin (S = 3/2) Cr3+ centers: one with D2h symmetry and another of triclinic symmetry. Quantitatively determined spin Hamiltonian parameters, including matrices g, D, and A(53Cr) and high-spin Zeeman term BS³, suggest that the D2h center represents a substitutional Cr3+ ion at the Si site without an immediate charge compensator. The triclinic center, which is characterized by a well-resolved ¹H superhyperfine structure, also arises from a substitutional Cr3+ ion at the Si site but has an H+ charge compensator bonded to one of the four equatorial oxygen atoms. The magnitude and orientation of the ¹H superhyperfine structure yield the location of the H atom at (0.46, 0.12, 0). These structural models for Cr and H in stishovite also have been corroborated by periodic density functional theory (DFT) calculations using the Vienna ab initio simulation package (VASP), with 2 x 2 x 4 supercells, plane-wave basis sets and the projector augmented wave (PAW) potentials. In addition, 85 K EPR spectra of irradiated stishovite show that the two Cr3+ centers are both converted to an S = 1/2 Cr5+ center characterized by two 29Si superhyperfine structures arising from interactions with two nearest and eight second-nearest Si atoms, respectively. The spin Hamiltonian parameters of this Cr5+ center provide further support for the location of the two Cr3+ centers at the Si site. [ABSTRACT FROM AUTHOR]

A total of 151 bacterial isolates were recovered from different developmental stages (larvae, nymphs and adults) of field-collected ticks (67 strains from Ixodes ricinus, 38 from Dermacentor reticulatus, 46 from Haemaphysalis concinna). Microorganisms were identified by means of 16S rRNA gene sequencing. Almost 87 % of the strains belonged to G+ bacteria with predominantly occurring genera Bacillus and Paenibacillus. Other G+ strains included Arthrobacter, Corynebacterium, Frigoribacterium, Kocuria, Microbacterium, Micrococcus, Plantibacter, Rhodococcus, Rothia, and Staphylococcus. G− strains occurred less frequently, comprising genera Advenella, Pseudomonas, Rahnella, Stenotrophomonas, and Xanthomonas. Several strains of medical importance were found, namely Advenella incenata, Corynebacterium aurimucosum, Microbacterium oxydans, M. schleiferi, Staphylococcus spp., and Stenotrophomonas maltophilia. Data on cultivable microbial diversity in Eurasian tick species D. reticulatus and H. concinna are given, along with the extension of present knowledge concerning bacterial flora of I. ricinus. [ABSTRACT FROM AUTHOR]

Members of the Bacteroidetes, formerly known as the Cytophaga-Flavobacteria-Bacteroides (CFB) phylum, are among the major taxa of marine heterotrophic bacterioplankton frequently found on macroscopic organic matter particles (marine snow). In addition, they have been shown to also represent a significant part of free-living microbial assemblages in nutrient-rich microenvironments. Their abundance and distribution pattern in combination with enzymatic activity studies has led to the notion that organisms of this group are specialists for degradation of high molecular weight compounds in both the dissolved and particulate fraction of the marine organic matter pool, implying a major role of Bacteroidetes in the marine carbon cycle. Despite their ecological importance, comprehensive molecular data on organisms of this group have been scarce so far. Here we report on the first whole genome analysis of a marine Bacteroidetes representative, ‘ Gramella forsetii’ KT0803. Functional analysis of the predicted proteome disclosed several traits which in joint consideration suggest a clear adaptation of this marine Bacteroidetes representative to the degradation of high molecular weight organic matter, such as a substantial suite of genes encoding hydrolytic enzymes, a predicted preference for polymeric carbon sources and a distinct capability for surface adhesion. [ABSTRACT FROM AUTHOR]

Questing Ixodes ricinus L. (Acari: Ixodidae) ticks were collected on a forest trail that had been completely cleared of shrubs and ground vegetation in winter 2002 and on a nearby control uncleared forest transect in South Moravia (Czech Republic). Samples were collected each May in 2003, 2004 and 2005. Nymphal ticks were 3.4 times, 1.9 times and 1.2 times less frequent on cleared forest than on uncleared forest trails in the three respective years, whereas adult tick abundance was 27.2 times, 4.0 times and 2.2 times lower, respectively. The ticks were examined for borreliae by dark-field microscopy: prevalence of nymphal ticks infected with Borrelia burgdorferi sensu lato (12.6% to 20.0%) did not differ significantly between the cleared and uncleared trail during the 3 years. In conclusion, the habitat modification appeared to result in a decreased abundance of I. ricinus as well as a reduced frequency of infected ticks (and thus indirectly a lower potential risk of Lyme borreliosis), which lasted, however, for only 2 years. Eight cultures of borreliae isolated from the ticks were all identified as the ‘ornithophilic’ genomic species Borrelia garinii, possibly indicating a greater role of forest birds than that of forest rodents as the hosts of immature I. ricinus in the tick (and borrelial) colonization of the cleared part of the forest. [ABSTRACT FROM AUTHOR]

The primary purpose of this study was to define the clinical and morphological features of cataractogenesis in the OXYS strain of rats that generate excess reactive oxygen species. Rats were sequentially examined from birth to the development of mature cataracts with slit lamp biomicroscopy. Morphology of selected stages of cataract development was studied using light and transmission electron microscopy (TEM), immunohistochemical localization of the lipid peroxidation product 4-hydroxynonenal (HNE) and fluorescent antibody labeling for DNA oxidation products. Lenses from age-matched normal rats were used as controls.OXYS rats developed cataracts as young as two weeks of age with progression to maturity by 1 year. Clinically, cataracts appeared initially either as nuclear or sub-capsular cortical changes and progressed to pronounced nuclear cataracts within months. TEM confirmed the light microscopic impression of region-specific alterations in both fiber cell cytoplasmic protein matrix and membrane structure. The outer adult nuclear region showed extensive cellular damage similar to osmotic cataracts, which is consistent with the postulated high uptake of glucose in the OXYS strain. The adult and outer fetal nuclear cells displayed several types of focal damage. The inner fetal and embryonic nuclear cells demonstrated textured cytoplasm, suggesting protein degradation or redistribution. Staining for HNE was increased in epithelium, cortex and nucleus compared to control lenses. Fluorescent antibody probes demonstrated increased levels of DNA oxidation products in OXYS rat lenses compared to age-matched controls. Fourier analysis of nuclear cytoplasm revealed significant components with corresponding sizes greater than 100 nm and, using a new theoretical approach, the texturing of the cytoplasm was shown to be sufficient to cause opacification of the nucleus. The OXYS rat appears to be an ideal model for oxidative stress cataractogenesis. The potential oxidative damage observed is extensive and characteristic of the developmental region. The source of oxidative damage may in part be a response to elevated levels of glucose. Because oxidative stress is thought to be a major factor in cataract formation in both diabetic and non-diabetic aging humans, this animal model may be a useful tool in assessing efficacy of antioxidant treatments that may slow or prevent cataract formation. [Copyright &y& Elsevier]

The unexpected presence of archaea-like genes for tetrahydromethanopterin (H4MPT)-dependent enzymes in the completely sequenced genome of the aerobic marine planctomycetePirellulasp. strain 1 (“Rhodopirellula baltica”) and in the currently sequenced genome of the aerobic freshwater planctomyceteGemmata obscuriglobusstrain UQM2246 revives the discussion on the origin of these genes in the bacterial domain. We compared the genomic arrangement of these genes inPlanctomycetesand methylotrophic proteobacteria and performed a phylogenetic analysis of the encoded protein sequences to address the question whether the genes have been present in the common ancestor ofBacteriaandArchaeaor were transferred laterally from the archaeal to the bacterial domain and therein. Although this question could not be solved using the data presented here, some constraints on the evolution of the genes involved in archaeal and bacterial H4MPT-dependent C1-transfer may be proposed: (i) lateral gene transfer (LGT) fromArchaeato a common ancestor ofProteobacteriaandPlanctomycetesseems more likely than the presence of the genes in the common ancestor ofBacteriaandArchaea; (ii) a single event of interdomain LGT can be favored over two independent events; and (iii) the archaeal donor of the genes might have been a representative of theMethanosarcinales. In the bacterial domain, the acquired genes evolved according to distinct environmental and metabolic constraints, reflected by specific rearrangements of gene order, gene recruitment, and gene duplication, with subsequent functional specialization. During the course of evolution, genes were lost from some planctomycete genomes or replaced by orthologous genes from proteobacterial lineages. [ABSTRACT FROM AUTHOR]

We hypothesized that the phytosterols β-sitosterol (BSS), β-sitosterol glucoside (BSSG), and Moducare (MC; BSS:BSSG = 99:1) could modulate the growth of estrogen-dependent human breast cancer cells in vitro and in vivo. The present study evaluated the estrogenic and antiestrogenic effects of BSS, BSSG, and MC (0.001 to 150 μmol/L) on the proliferation of Michigan Cancer Foundation 7 (MCF-7) cells in vitro. Both BSS (>1 μmol/L) and MC (>50 μmol/L) increased MCF-7 cell proliferation. Treatment with 150 μmol/L of BSS and MC increased cell growth by 2.4 and 1.5 times, respectively, compared to the negative control (NC) group. However, BSSG had no effect at the concentrations tested. The effects of dietary BSS, BSSG, and MC on the growth of MCF-7 cells implanted in ovariectomized athymic mice were also evaluated. Estrogenic effects of the phytosterols were evaluated in the NC, BSS, BSSG, and MC treatment groups, and antiestrogenic effects were evaluated in the 17β-estradiol (E2), E2 + BSS, E2 + BSSG, and E2+ MC treatment groups. Mice were treated with dietary BSS (9.8 g/kg AIN93G diet), BSSG (0.2 g/kg diet), or MC (10.0 g/kg diet) for 11 wk. Dietary BSS, BSSG, and MC did not stimulate MCF-7 tumor growth. However, dietary BSS, BSSG, and MC reduced E2-induced MCF-7 tumor growth by 38.9% (P < 0.05), 31.6% (P = 0.08), and 42.13% (P < 0.05), respectively. The dietary phytosterols lowered serum E2 levels by 35.1, 30.2, and 36.5% in the E2 + BSS, E2 + BSSG, and E2+ MC groups, respectively (P < 0.05), compared to that of the E2 treatment group. Estrogen-responsive pS2 mRNA expression in tumors did not differ among groups, but expression of the antiapoptotic marker B-cell lymphoma/leukemia-2 (bcl-2) in tumors from the E2 + MC group was downregulated, compared to that of the E2 treatment group. In summary, BSS and MC stimulated MCF-7 cell growth in vitro. Although BSSG comprises only 1% of MC, BSSG made MC less estrogenic than BSS alone in vitro. However, dietary BSS and MC protected against E2-stimulated MCF-7 tumor growth and lowered circulating E2 levels. [ABSTRACT FROM AUTHOR]

Summary Filamentous sulphide-oxidizing Beggiatoa spp. often occur in large numbers in the coastal seabed without forming visible mats on the sediment surface. We studied the diversity, population structure and the nitrate-storing capability of such bacteria in the Danish Limfjorden and the German Wadden Sea. Their distribution was compared to the vertical gradients of O2 , NO3 – and H2 S as measured by microsensors. The main Beggiatoa spp. populations occurred in a 0.5–3 cm thick intermediate zone, below the depth of oxygen and nitrate penetration but above the zone of free sulphide. The Beggiatoa spp. filaments were found to store nitrate, presumably in liquid vacuoles up to a concentration of 370 mM NO3 – , similar to the related large marine sulphur bacteria, Thioploca and Thiomargarita . The observations indicate that marine Beggiatoa spp. can live anaerobically and conserve energy by coupling sulphide oxidation with the reduction of nitrate to dinitrogen and/or ammonia. Calculations of the diffusive nitrate flux and the potential sulphide oxidation by Beggiatoa spp. show that the bacteria may play a critical role for the sulphur cycling and the nitrogen balance in these coastal environments. 16S rDNA sequence analysis shows a large diversity of these uncultured, nitrate-storing Beggiatoa spp. Smaller (9–17 µm wide) and larger (33–40 µm wide) Beggiatoa spp. represent novel phylogenetic clusters distinct from previously sequenced, large marine Beggiatoa spp. and Thioploca spp. Fluorescence in situ hybridization (FISH) of the natural Beggiatoa spp. populations showed that filament width is a conservative character of each phylogenetic species but a given filament width may represent multiple phylogenetic species in a mixed population. [ABSTRACT FROM AUTHOR]

Apoptosis, or regulated cell suicide, eliminates unwanted and damaged cells, including precancerous and cancerous cells. Since reactive oxygen species (ROS) act as essential apoptotic mediators, we reasoned that increasing the ROS level might enhance apoptosis and thereby slow down tumor growth. Here, using a defined transgenic brain tumor model with known tumor apoptosis rates, we test the impact of antioxidant-depleted diet, capable of increasing ROS levels, or antioxidant-enriched diets on tumor growth. Dramatically increased apoptosis occurs within tumors, but not in normal tissues of antioxidant-depleted mice. The presence of detectable increased oxidant stress within tumors indicates that the likely mechanism of enhanced tumor apoptosis is via ROS and DNA oxidative impairment. Importantly, due to the ROS-enhanced apoptosis, tumor growth is inhibited in mice fed an antioxidant-depleted diet. In clear contrast, an antioxidant-rich diet had no impact on tumor growth. [ABSTRACT FROM PUBLISHER]

Electron paramagnetic resonance (EPR) in a synthetic Si 0.975 Ge 0.025 O 2 single crystal of α–quartz structure has been studied. After fast electron irradiation previously studied and new Ge-related paramagnetic centers (PCs) have been recognized using computer simulation of the observed EPR spectra. Increasing radiation doses allow to distinguish four paramagnetic [GeO 4 /M+]0 centers A GeLi , C GeLi , D GeLi , and A GeNa as well as four oxygen-vacancy electron centers Ge E ˊ 1 , Ge E ˊ 2 , Ge(IV) and a new Ge(V) center. The selective UV bleaching and distinct thermal stability of different centers allow us to determine the spin Hamiltonian parameters for the Ge(V) center. Electron paramagnetic resonance (EPR) in a synthetic Si 0.975 Ge 0.025 O 2 single crystal of α–quartz structure has been studied. Detailed EPR measurements after different storage times, radiation doses, thermal annealing, and UV bleaching as well as computer simulations allow us to distinguish four [GeO 4 /M+]0 centers A GeLi , C GeLi , D GeLi , and A GeNa as well as four oxygen-vacancy electron centers Ge E ˊ 1 , Ge E ˊ 2 , Ge(IV) and Ge(V). The spin Hamiltonian parameters (g , A (73Ge) and P (73Ge) of the new Ge(V) center have been determined and are closely comparable to those of the Ge E ˊ 1 center. [Display omitted] • Single crystals of Ge-rich α-quartz were grown hydrothermally. • Ge-related paramagnetic defects are induced by fast electron irradiation. • Paramagnetic defects are identified using computer simulations of EPR spectra. • Spin Hamiltonian parameters for new Ge(V) oxygen vacancy defect are determined. [ABSTRACT FROM AUTHOR]

Examines the use of in situ hybridization method for the specific detection of pathogenic Candida species by designing an oligonucleotide probe which binds to the 18S rRNA of Candida albicans and Candida tropicalis. Selection of an oligonucleotide probe specific for C. albicans and C. tropicalis; Confirmation of probe specificity.

Presents a method in the identification and in situ detection of individual microbial cells without cultivation. Use of a combination of direct retrieval of ribosomal RNA (rRNA) sequences and whole-cell oligonucleotide probing in identifying and detecting uncultured bacteria; Problems associated with direct microscopic observation in detecting bacteria.

In situ hybridization with rRNA-targeted, fluorescent (Cy3-labeled) oligonucleotide probes was used to analyze bacterial community structure in ethanol- or paraformaldehyde-fixed bulk soil after homogenization of soil samples in 0.1% pyrophosphate by mild ultrasonic treatment. In ethanol-fixed samples 37 ± 7%, and in paraformaldehyde 41 ± 8% of the 4′, 6-diamidino-2-phenylindole(DAPI)-stained cells were detected with the bacterial probe Eub338. The yield could not be increased by enzymatic and/or chemical pretreatments known to enhance the permeability of bacterial cells for probes. However, during storage in ethanol for 7 months, the detectability of bacteria increased in both ethanol- and paraformaldehyde-fixed samples to up to 47 ± 8% due to an increase in the detection yield of members of the α-subdivision of Proteobacteria from 2 ± 1% to 10 ± 3%. Approximately half of the bacteria detected by probe Eub338 could be affiliated to major phylogenetic groups such as the α-, β-, γ-, and δ-subdivisions of Proteobacteria, gram-positive bacteria with a high G+C DNA content, bacteria of the Cytophaga-Flavobacterium cluster of the CFB phylum, and the planctomycetes. The analysis revealed that bacteria of the α- and δ-subdivision of Proteobacteria and the planctomycetes were predominant. Here, members of the α-subdivision of Proteobacteria accounted for approximately 10 ± 3% of DAPI-stained cells, which corresponded to 44 ± 16 × 108 cells (g soil, dry wt.)–1, while members of the δ-subdivision of Proteobacteria made up 4 ± 2% of DAPI-stained cells [17 ± 9 × 108 cells (g soil, dry wt.)–1]. A large population of bacteria in bulk soil was represented by the planctomycetes, which accounted for 7 ± 3% of DAPI-stained cells [32 ± 12 × 108 cells (g soil, dry wt.)–1]. The detection of planctomycetes in soil confirms previous reports on the occurrence of planctomycetes in soil and indicates a yet unknown ecological significance of this group, which to date has never been isolated from terrestrial environments. [ABSTRACT FROM AUTHOR]

Target regions specific for the class Prymnesiophyceae and the genus Phaeocystis (Har.) Lag., were identified from 18S ribosomal RNA coding regions, and two complementary probes were designed (PRYMN01 and PHAEO01). Detection of whole cells hybridized with these probes labeled with fluorescein isothiocyanate was difficult using epifluorescence microscopy because autofluorescence of the chlorophylls seriously interfered with the fluorescence of the probes. In contrast, flow cytometry proved very useful to detect and quantify the fluorescence of the hybridized cells. Hybridization conditions were opotimized, especially with respect to formamide concentration. Both probes were tested on a large array of both target and nontarget strains. Positive and negative controls were also analyzed. Specificity was tested by adding a competing nonlabled probe. Whereas probe PHAEO01 appeared less specific and must be used with stringent positive and negative controls. [ABSTRACT FROM AUTHOR]

The nitrogen mustard mechlorethamine (NH2) is a potent contact allergen, sensitizing up to 75% of those exposed. An attempt was made to prevent allergic contact sensitization, i.e. to induce specific immunologic tolerance, in 9 patients who were to be treated topically with NH2 for widespread and persistent psoriasis. Fourteen and 7 days before the first topical application of NH2, they were given intravenous injections of 3 trig NH2. Topical treatment with NH2 was repeated weekly for 8 to 10 weeks in 4 patients and daily for about 4 weeks in 5 patients. Two of the 9 patients became contact allergic to NH2. Despite the apparent failure to induce tolerance, further trials in a larger series of patients and trials with different "tolerogenic" schedules and different topical treatment schedules are warranted. [ABSTRACT FROM AUTHOR]