1,874 research outputs found
Vanadium-rich Muscovite from Austria: Crystal Structure, Chemical Analysis, and Spectroscopic Investigations
The crystal structure of a green, transparent, vanadium-rich muscovite-2M_1 (V_2O_3 = 11.35 wt.%, one of the highest amounts reported to date in muscovite) with the optimized formula (K_(0.94)Na_(0.06))M2(Al_(1.20)V^(3+)_(0.61)Mg_(0.12)Cr^(3+)_(0.07))T1(Si^(1.54)Al_(0.46))T2(Si_(1.54)Al_(0.46))O_(10)(OH)_2 and space group C2/c, a 5.2255(6), b 9.0704(10), c 20.0321(21) Å, β 95.773(2)°, Z = 4 has been refined to R = 6.97% for 1070 unique reflections (MoKα). This muscovite, which occurs in small quartz veins in graphite schist from Weinberg mountain, near the village of Amstall, Lower Austria, is distinctly low in Cr (Cr_2O_3 ∼1.4 wt.%) and Mg (MgO ∼1.1 wt.%); Fe, Mn, and Ti are below detection limit. All octahedral cations occupy the M2 site, and the average octahedral bond (M2–O) distance is 1.953 Å. Structural distortions include α = 8.89° and Δz = 0.193 Å, resulting in an interlayer spacing of 3.35 Å. The optical absorption spectrum of this V-rich muscovite shows absorption features at 427 and 609 nm that define a transmission window centered at 523 nm. These absorption features are consistent with those expected for V^(3+) in mica, but the 609 nm band has a slightly longer wavelength than in low-V micas
Book Reviews
THE SUPREME COURT AND RELIGION. By Richard E. Morgan. New York: The Free Press, 1972. Pp. 216. 1.95.
PRIVATE INTEREST AND PUBLIC GAIN: THE DARTMOUTH COLLEGE CASE, 1819. By Francis N. Stites. Amherst: The University of Massachusetts Press, 1972. Pp. 176. 6.95
Interleukin-4 induction of the CC chemokine TARC (CCL17) in murine macrophages is mediated by multiple STAT6 sites in the TARC gene promoter
BACKGROUND: Macrophages (Mθ) play a central role in the innate immune response and in the pathology of chronic inflammatory diseases. Macrophages treated with Th2-type cytokines such as Interleukin-4 (IL-4) and Interleukin-13 (IL-13) exhibit an altered phenotype and such alternatively activated macrophages are important in the pathology of diseases characterised by allergic inflammation including asthma and atopic dermatitis. The CC chemokine Thymus and Activation-Regulated Chemokine (TARC/CCL17) and its murine homologue (mTARC/ABCD-2) bind to the chemokine receptor CCR4, and direct T-cell and macrophage recruitment into areas of allergic inflammation. Delineating the molecular mechanisms responsible for the IL-4 induction of TARC expression will be important for a better understanding of the role of Th2 cytokines in allergic disease. RESULTS: We demonstrate that mTARC mRNA and protein are potently induced by the Th2 cytokine, Interleukin-4 (IL-4), and inhibited by Interferon-γ (IFN-γ) in primary macrophages (Mθ). IL-4 induction of mTARC occurs in the presence of PI3 kinase pathway and translation inhibitors, but not in the absence of STAT6 transcription factor, suggesting a direct-acting STAT6-mediated pathway of mTARC transcriptional activation. We have functionally characterised eleven putative STAT6 sites identified in the mTARC proximal promoter and determined that five of these contribute to the IL-4 induction of mTARC. By in vitro binding assays and transient transfection of isolated sites into the RAW 264.7 Mθ cell-line, we demonstrate that these sites have widely different capacities for binding and activation by STAT6. Site-directed mutagenesis of these sites within the context of the mTARC proximal promoter revealed that the two most proximal sites, conserved between the human and mouse genes, are important mediators of the IL-4 response. CONCLUSION: The induction of mTARC by IL-4 results from cooperative interactions between STAT6 sites within the mTARC gene promoter. Significantly, we have shown that transfer of the nine most proximal mTARC STAT6 sites in their endogenous conformation confers potent (up to 130-fold) IL-4 inducibility on heterologous promoters. These promoter elements constitute important and sensitive IL-4-responsive transcriptional units that could be used to drive transgene expression in sites of Th2 inflammation in vivo
Genotoxicity of 3-nitrobenzanthrone and 3-aminobenzanthrone in Mutaâ„¢Mouse and lung epithelial cells derived from Mutaâ„¢Mouse
FE1 lung epithelial cells derived from Muta (TM) Mouse are a new model system to provide in vitro mutagenicity data with the potential to predict the outcome of an in vivo Muta (TM) Mouse test. 3-Nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust and urban air pollution. We investigated the mutagenicity and DNA binding of 3-NBA and its main metabolite 3-aminobenzanthrone (3-ABA) in vitro and in vivo in the Muta (TM) Mouse assay. Mice were treated with 3-NBA or 3-ABA (0, 2 or 5 mg/kg body weight/day) by gavage for 28 days and 28 days later lacZ mutant frequency (MF) was determined in liver, lung and bone marrow. For both compounds, dose-related increases in MF were seen in liver and bone marrow, but not in lung; mutagenic activity was similar to 2-fold lower for 3-ABA than for 3-NBA. With 3-NBA, highest DNA adduct levels (measured by P-32-post-labelling) were found in liver (similar to 230 adducts per 10(8) nucleotides) with levels 20- to 40-fold lower in bone marrow and lung. With 3-ABA, DNA adduct levels were again highest in the liver, but similar to 4-fold lower than for 3-NBA. FE1 cells were exposed to up to 10 mu g/ml 3-NBA or 3-ABA for 6 h with or without exogenous activation (S9) and harvested after 3 days. For 3-NBA, there was a dose-related increase in MF both with and without S9 mix, which was > 10 times higher than observed in vivo. At the highest concentration of 3-ABA (10 mu g/ml), we found only around a 2-fold increase in MF relative to controls. DNA adduct formation in FE1 cells was dose-dependent for both compounds, but 10- to 20-fold higher for 3-NBA compared to 3-ABA. Collectively, our data indicate that Muta (TM) Mouse FE1 cells are well suited for cost-effective testing of suspected mutagens with different metabolic activation pathways as a guide for subsequent in vivo Muta (TM) Mouse testing
Vanadium-rich Muscovite from Austria: Crystal Structure, Chemical Analysis, and Spectroscopic Investigations
The crystal structure of a green, transparent, vanadium-rich muscovite-2M_1 (V_2O_3 = 11.35 wt.%, one of the highest amounts reported to date in muscovite) with the optimized formula (K_(0.94)Na_(0.06))M2(Al_(1.20)V^(3+)_(0.61)Mg_(0.12)Cr^(3+)_(0.07))T1(Si^(1.54)Al_(0.46))T2(Si_(1.54)Al_(0.46))O_(10)(OH)_2 and space group C2/c, a 5.2255(6), b 9.0704(10), c 20.0321(21) Å, β 95.773(2)°, Z = 4 has been refined to R = 6.97% for 1070 unique reflections (MoKα). This muscovite, which occurs in small quartz veins in graphite schist from Weinberg mountain, near the village of Amstall, Lower Austria, is distinctly low in Cr (Cr_2O_3 ∼1.4 wt.%) and Mg (MgO ∼1.1 wt.%); Fe, Mn, and Ti are below detection limit. All octahedral cations occupy the M2 site, and the average octahedral bond (M2–O) distance is 1.953 Å. Structural distortions include α = 8.89° and Δz = 0.193 Å, resulting in an interlayer spacing of 3.35 Å. The optical absorption spectrum of this V-rich muscovite shows absorption features at 427 and 609 nm that define a transmission window centered at 523 nm. These absorption features are consistent with those expected for V^(3+) in mica, but the 609 nm band has a slightly longer wavelength than in low-V micas
Reduction of dioxin-like toxicity in effluents by additional wastewater treatment and related effects in fish
Population-genetic comparison of the Sorbian isolate population in Germany with the German KORA population using genome-wide SNP arrays
<p>Abstract</p> <p>Background</p> <p>The Sorbs are an ethnic minority in Germany with putative genetic isolation, making the population interesting for disease mapping. A sample of N = 977 Sorbs is currently analysed in several genome-wide meta-analyses. Since genetic differences between populations are a major confounding factor in genetic meta-analyses, we compare the Sorbs with the German outbred population of the KORA F3 study (N = 1644) and other publically available European HapMap populations by population genetic means. We also aim to separate effects of over-sampling of families in the Sorbs sample from effects of genetic isolation and compare the power of genetic association studies between the samples.</p> <p>Results</p> <p>The degree of relatedness was significantly higher in the Sorbs. Principal components analysis revealed a west to east clustering of KORA individuals born in Germany, KORA individuals born in Poland or Czech Republic, Half-Sorbs (less than four Sorbian grandparents) and Full-Sorbs. The Sorbs cluster is nearest to the cluster of KORA individuals born in Poland. The number of rare SNPs is significantly higher in the Sorbs sample. FST between KORA and Sorbs is an order of magnitude higher than between different regions in Germany. Compared to the other populations, Sorbs show a higher proportion of individuals with runs of homozygosity between 2.5 Mb and 5 Mb. Linkage disequilibrium (LD) at longer range is also slightly increased but this has no effect on the power of association studies.</p> <p>Oversampling of families in the Sorbs sample causes detectable bias regarding higher FST values and higher LD but the effect is an order of magnitude smaller than the observed differences between KORA and Sorbs. Relatedness in the Sorbs also influenced the power of uncorrected association analyses.</p> <p>Conclusions</p> <p>Sorbs show signs of genetic isolation which cannot be explained by over-sampling of relatives, but the effects are moderate in size. The Slavonic origin of the Sorbs is still genetically detectable.</p> <p>Regarding LD structure, a clear advantage for genome-wide association studies cannot be deduced. The significant amount of cryptic relatedness in the Sorbs sample results in inflated variances of Beta-estimators which should be considered in genetic association analyses.</p
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