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1.
Matthew G. Permenter William E. Dennis Thomas E. Sutto David A. Jackson John A. Lewis Jonathan D. Stallings 《PloS one》2013,8(12)
Cobalt is a transition group metal present in trace amounts in the human diet, but in larger doses it can be acutely toxic or cause adverse health effects in chronic exposures. Its use in many industrial processes and alloys worldwide presents opportunities for occupational exposures, including military personnel. While the toxic effects of cobalt have been widely studied, the exact mechanisms of toxicity remain unclear. In order to further elucidate these mechanisms and identify potential biomarkers of exposure or effect, we exposed two rat liver-derived cell lines, H4-II-E-C3 and MH1C1, to two concentrations of cobalt chloride. We examined changes in gene expression using DNA microarrays in both cell lines and examined changes in cytoplasmic protein abundance in MH1C1 cells using mass spectrometry. We chose to closely examine differentially expressed genes and proteins changing in abundance in both cell lines in order to remove cell line specific effects. We identified enriched pathways, networks, and biological functions using commercial bioinformatic tools and manual annotation. Many of the genes, proteins, and pathways modulated by exposure to cobalt appear to be due to an induction of a hypoxic-like response and oxidative stress. Genes that may be differentially expressed due to a hypoxic-like response are involved in Hif-1α signaling, glycolysis, gluconeogenesis, and other energy metabolism related processes. Gene expression changes linked to oxidative stress are also known to be involved in the NRF2-mediated response, protein degradation, and glutathione production. Using microarray and mass spectrometry analysis, we were able to identify modulated genes and proteins, further elucidate the mechanisms of toxicity of cobalt, and identify biomarkers of exposure and effect in vitro, thus providing targets for focused in vivo studies. 相似文献
2.
Sigbritt Karlsson Zoltan G. Banhidi Ann-Christine Albertsson 《Applied microbiology and biotechnology》1988,28(3):305-310
Summary Reports on malodour in buildings constructed in the late 1970s gave rise to thorough investigations on the possible role of vapours of chemical compounds emitted by building materials. The odour could be related to the use of casein as an additive to improve the fluidity of concrete materials used as a self-levelling floor topping compound. Casein was suggested to be degraded by microorganisms, resulting in an accumulation of malodorous substances in the topping compounds.Bacteria isolated from biodeteriorated concrete materials containing caseins exhibited unusual tolerance towards high pH. Two dominant species were found among a total of 80 sporeforming, anaerobic isolates from concrete and raw products of caseins, namely Clostridium bifermentans and Clostridium sporogenes. C. bifermentans had a maximal pH tolerance of 12.2 while C. sporogenes could reproduce up to pH 11.7. The study includes the identification of the clostridia with API multitest as well as an investigation of the volatile organic acid and monoamine patterns. About 100 cfu clostridia/g material could be obtained during the isolation procedures. 相似文献
3.
4.
Mineral uptake by winter wheat (Trilicum aestivum L. cv. Martonvasari 8) was studied throughout the life cycle. Accumulation of macronutrients (i.e. total nitrogen, phosphorus, potassium, sodium, magnesium and calcium) and the water content of roots and shoots of plants grown in complete nutrient solution were higher than those of plants grown in two types of soils. The supply of macronutrients was in some cases limiting for soil-grown plants as revealed by a comparison of available and accumulated amounts of these nutrients. Their supply was abundant, however, for solution-grown plants. This led to a doubling of grain yield for the latter plants with a three fold increase in accumulation of dry matter and a five-fold increase in fresh weight. The efficiency ratios of solution-grown plants to soil-grown plants were approximately 1 for N and Na, 0.5 for Mg and Ca, and 0.3 for P and K. 相似文献
5.
The application of cellulose-based stationary phases for chiral separations has been extended to open tubular column chromatography. Efficient columns were obtained by coating the capillaries with mixtures of chiral cellulose materials and conventional achiral stationary phases for gas chromatography. In this study, various siloxane and polyethylene glycol polymers were used as achiral components and mixed with different substituted benzoylcellulose derivatives as chiral components. Systematic investigations were carried out to determine the optimal ratio for the components of the stationary phase. Depending on the chromatographic mode—gas chromatography (GC) or supercritical fluid chromatography (SFC)—the stationary phases were found to behave differently. The applicability of the technique was demonstrated by the resolution of various racemic compounds. © 1993 Wiley-Liss, Inc. 相似文献
6.
7.
Sujay K. Singh Edward K. Wakeland Ivica Vučak Zoltan A. Nagy Jan Klein 《Immunogenetics》1981,14(3-4):273-281
The B10.STA62 strain carries the H-2
w27 haplotype derived from a wild mouse captured in the vicinity of Ann Arbor, Michigan. Products of two class II loci composing this haplotype, A
and A
, are serologically, biochemically (by tryptic peptide mapping), and functionally indistinguishable from products controlled by the A
b
and A
/b
genes of the B10.A(5R) strain. In contrast, the polypeptide chain controlled by the third class II locus, E
, is different from that controlled by the E
/b
gene. This E
/w27
chain lacks an antigenic determinant present on the Eb molecule and carries determinants lacking on the Eb molecule, the E
/b
and E
/w27
peptide maps differ in at least six peptides, and cytotoxic T cells specific for the E
b
chains do not react with B10.STA62 target cells. This great difference between the E
/b
and E
/w27
chains suggests that the corresponding genes have not been derived from one another by a direct mutational conversion; instead, H-2
w27 appears to be a recombinant haplotype derived by crossing-over between the A
A
duplex and the E
locus. This is the first recombinant discovered separating these class II loci. 相似文献
8.
Summary Hydrophobie zeolite Y was used to adsorb detergents from protein solutions and within one minute the commonly used detergents sodium dodecyl sulfate, cetyl trimethyl ammonium bromide, and Triton X-100 at concentrations of 10 mg/ml were adsorbed to a level below their critical micelle concentrations. From the detergent depleted solutions 77 to 85 % of the proteins were recovered; the lower value was obtained with protein concentration below one mg/ml. 相似文献
9.
Cell-mediated lymphocytotoxicity was generated in four strain combinations differing only by the cell-surface expression of the class II E molecule controlled by the H-2 complex. The four combinations were: B10.D2(R107) anti-B10.A(3R), B10.A(4R) anti-B10.A(2R), B10.GD anti-B10.D2(R101), and B10.S(7R) anti-B10.S(9R). In all four of these combinations, the stimulator expresses E molecules on the cell surface, while the responder does not. The cytolytic T lymphocytes generated in the B10.D2(R107) anti-B10.A(3R) and B10.A(4R) anti-B10.A(2R) combinations reacted not only with the stimulator but also with strains that do not express cell-surface E molecules, in particular, strains carrying the H-2
f
and H-2
q
haplotypes. The cross-reactivity with E-negative strains could be blocked by monoclonal antibodies specific for the Af or Aq molecules but not by antibodies recognizing determinants on E or class I (K) molecules. The anti-H-2f cross-reactivity could be inhibited by H-2
q
cold targets and, reciprocally, the anti-H-2q reactivity could be blocked by H-2
f
cold targets. These findings are interpreted as indicating that the cytolytic T lymphocytes stimulated by E molecules can recognize and lyse cells lacking E molecules but expressing A molecules. The observed E-A cross-reactivity supports the notion of structural and functional relatedness between the A and E molecules and suggests a common evolutionary origin of the A- and E-encoding loci. 相似文献
10.
Waldemar Adam Zoltan Lukacs Claudia Kahle Chantu R. Saha-Mller Peter Schreier 《Journal of Molecular Catalysis .B, Enzymatic》2001,11(4-6):377-385
Screening of soil bacteria with allylbenzene resulted in a Bacillus megaterium strain, which hydroxylates simple hydrocarbons in high enantiomeric excess (ee up to 99%). Benzylic and nonbenzylic hydroxylation products were obtained, without the usually observed high preference for the benzylic position. The immobilization of the B. megaterium cells in alginate gel effectively improved the stability of the cells and increased the amounts of products formed, without loss of enantioselectivity. The product ratio ( vs. β hydroxylation) was shifted towards benzylic hydroxylation, which suggests that at least two hydroxylating enzymes with distinct regioselectivity are involved. Comparison to free-cell fermentations in small- and large-scale bioreactors (up to 2000 ml) showed that the use of immobilized cells is advantageous, as they are easier to handle and yield higher amounts of oxidation products. 相似文献