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61.
Glycogen synthesis, whether in mammalian tissue, yeast, or Agrobacterium tumefaciens or other bacteria, is initiated by autoglucosylation of a protein. Initiation in muscle, by a self-glucosylating protein, glycogenin-1, is the most thoroughly studied system, as is described here. These relatively recent findings have prompted a rekindling of interest in the intermediates lying between the primer and mature mammalian glycogen. 相似文献
62.
Navet R Douette P Puttine-Marique F Sluse-Goffart CM Jarmuszkiewicz W Sluse FE 《FEBS letters》2005,579(20):4437-4442
In isolated potato tuber mitochondria, palmitic acid (PA) can induce a H+ leak inhibited by GTP in the phosphorylating (state 3) respiration but not in the resting (state 4) respiration. The PA-induced H+ leak is constant when state 3 respiration is decreased by an inhibition of the succinate uptake with n-butyl malonate (nBM). We show that the efficiency of inhibition by GTP is decreased when state 3 respiration is progressively inhibited by antimycin A (AA) and is restored following subsequent addition of nBM. We propose that in phosphorylating potato tuber mitochondria, the redox state of ubiquinone, which can antagonistically be varied with AA and nBM, modulates inhibition of the PA-activated UCP-sustained H+ leak by GTP. 相似文献
63.
Guttenplan JB Spratt TE Khmelnitsky M Kosinska W Desai D El-Bayoumy K 《Mutation research》2004,559(1-2):199-210
We have studied the effects of three chemopreventive agents alone or in binary combinations on benzo[a]pyrene (BaP)-induced mutagenesis in the oral cavity and esophagus of lacZ mice using galE(-) selection. The mice were fed diets supplemented with 1,4-phenylenebis(methylene)selenocyanate (p-XSC) at 2.5 and 10 ppm Se, selenium-enriched yeast (SeY) at 2.5 and 10 ppm Se, and 3H-1,2-dithiole-3-thione (D3T) at 65 and 250 ppm, for 6 weeks. Two weeks after the start of the dietary regimen, mice were gavaged with five doses of 125 mg/kg BaP over 2 weeks, and the experiment was terminated 2 weeks later. Mutagenesis was measured in tongue, other pooled oral tissues (OTs), and esophagus. In mice treated with BaP alone, mutagenesis in the above tissues was in the range of 21-32 mutants/10(5)pfu (ca. 6-10 background levels for the corresponding tissues). p-XSC modestly inhibited mutagenesis (10-33% inhibition) in all tissues, but statistical significance was only observed at the low dose in esophagus, and pooled OT. SeY was not inhibitory alone. Greater inhibitory effects were observed with D3T, and inhibition was statistically significant at the high dose in tongue and esophagus (ca. 33%). Two combinations of low doses of the inhibitors were tested, and the D3T + SeY mix was most effective, leading to statistically significant inhibition in all three tissues (ca. 30-40% inhibition). The mixture D3T + p-XSC was of similar effectiveness as the low dose of D3T alone. This study combined with those previously done in our laboratory demonstrates effectiveness of D3T and to a lesser extent, p-XSC in the inhibition of mutagenesis, and provides support for the use of certain combinations of inhibitors as a means to increase effectiveness and reduce the dose of chemopreventive agents. 相似文献
64.
Cryptosporidium parvum and Giardia lamblia recovered from flies on a cattle farm and in a landfill 总被引:3,自引:0,他引:3
Szostakowska B Kruminis-Lozowska W Racewicz M Knight R Tamang L Myjak P Graczyk TK 《Applied and environmental microbiology》2004,70(6):3742-3744
Filth flies associated with a cattle barn and a municipal landfill were tested positive by combined immunofluorescent antibody and fluorescent in situ hybridization for Cryptosporidium parvum and Giardia lamblia on their exoskeletons and in their guts. More pathogens were carried by flies from the cattle barn than from the landfill; 81% of C. parvum and 84% of G. lamblia pathogens were presumptively viable. 相似文献
65.
In this study we show that mitochondria of Dictyostelium discoideum contain both alternative oxidase (AOX) and uncoupling protein (UCP). AOX was stimulated by purine mononucleoside and was monomeric. UCP was stimulated by free fatty acids and was poorly sensitive to GTP. Both proteins collaborated in energy dissipation when activated together. AOX expression in free-living ameboid cells decreased strongly from exponential to stationary phase of growth but much less during starvation-induced aggregation. In contrast, UCP expression was constant in all conditions indicating permanent need. Our results suggest that AOX could play a role in cell differentiation, mainly by protecting prespore cells from programmed cell death. 相似文献
66.
Differentiation of Acerpseudoplatanus L. cells into tracheary elements (TE) and an increase in the number of TE inHaplopappus gracilis (Nutt.) A. Gray calli were observed after pulse-treatment of the cultures grown in glass tubes with indole-3-acetic acid
(IAA) solutions. The effect was enhanced if the treatment was repeated in three subsequent days. The manner of IAA application
which caused a wave-like pattern of IAA flow through the callus culture appeared to be more important than the IAA concentration.
Induction of differentiation of A.pseudoplatanus cells and an increase in the number of TE inH. gracilis callus did not occur when the calli were grown on agar media supplemented with increased concentrations of IAA. 相似文献
67.
INHIBITION OF ALANINE AND ASPARTATE AMINOTRANSFERASES BY α-OXODERIVATIVES OF THE BRANCHED-CHAIN AMINO ACIDS 总被引:1,自引:1,他引:0
Wieslawa Lysiak Maria Pienkowska-Vogel A. Szutowicz S. Angielski 《Journal of neurochemistry》1974,22(1):77-83
Abstract—
- 1 L-Alanine: α-oxoglutarate aminotransferase was partly purified from rat brain and liver. The enzyme from the brain has about 10 times less activity than that from the liver.
- 2 Both enzymes have identical apparent Km values for L-alanine, L-glutamate, α-oxoglutarate and pyruvate. Moreover they are competitively inhibited by L-leucine. α-oxoisocaproate and α-oxotsovalerate. Obtained K, values are very similar and do not depend on the course of reaction.
- 3 α-Oxoisocaproate inhibits the activity of crystalline L-aspartate: α-oxoglutarate aminotransferase; Kj is about 4–7 mM.
- 4 The pyridoxamine form of L-alanine: α-oxoglutarate aminotransferase seems to be more sensitive to the inhibitory effect of the compounds investigated.
- 5 The effect of branched-chain amino acids and their α-oxoanalogues on the metabolism of amino groups in maple syrup urine disease is discussed.
68.
Moss RB Richieri SP Ferre F Daigle AE Trauger R Theofan G Giermakowska W Lanza P Brostoff S Carlo DJ Jensen FC 《Journal of biomedical science》1997,4(4):127-131
The impairment of lymphocytes to proliferate to HIV antigen is a relatively early functional defect of cell-mediated immunity found in HIV-infected individuals. The finding of strong proliferative responses in nonprogressive HIV disease as well as its inverse association with viral load and clinical manifestation of AIDS supports the further use of this marker as a surrogate of disease progression. The observation that HIV-specific lymphocyte proliferation is associated with the production of CD8-derived HIV suppressive factors such as the -chemokines further supports this conclusion. These functional immune measurements provide an additional marker to monitor disease progression in HIV-infected individuals, along with the current standards of CD4 counts and viral load. 相似文献
69.
Sulewska A Niklinska W Kozlowski M Minarowski L Naumnik W Niklinski J Dabrowska K Chyczewski L 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2007,45(4):315-324
The methods of molecular biology allow for analyzing the methylation pattern in the whole genome and in particular genes. We differentiate methylated sequences from unmethylated ones by means of cutting the genomic template with methylation-sensitive restriction enzymes or by sodium bisulfite DNA modification. Chemical modification precedes most quantitative and qualitative PCR techniques: MS-PCR, MS-nested PCR, Real-Time PCR, QAMA, HeavyMethyl, MSHRM. Restriction enzymes, on the other hand, may be used together with PCR or hybridisation methods (Southern blot and microarrays). PCRs are conducted with primers specific for methylated and unmethylated sequences and sometimes, similarly to hybridisation techniques, with specifically labeled probes or dyes intercalating to double-stranded nucleic acids. The most advanced methylation detection techniques (MALDI-TOF MS and HPLC) significantly reduce the amount of biological material used for tests, but they require specialist equipment. 相似文献
70.
Integrated genomics identifies five medulloblastoma subtypes with distinct genetic profiles, pathway signatures and clinicopathological features 总被引:1,自引:0,他引:1
Kool M Koster J Bunt J Hasselt NE Lakeman A van Sluis P Troost D Meeteren NS Caron HN Cloos J Mrsić A Ylstra B Grajkowska W Hartmann W Pietsch T Ellison D Clifford SC Versteeg R 《PloS one》2008,3(8):e3088