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31.
Joseph H. Fleisher Klaus Brendel Milos Chvapil Erle E. Peacock 《Analytical biochemistry》1976,74(1):254-259
Thin-layer chromatography of β-aminopropionitrile (BAPN) in acetone and 1 m ammonium hydroxide (9:1) allowed separation of that compound from amino acids present in rat-liver perfusion fluid without prior solvent extraction. Direct densitometry of the spots obtained with ninhydrin yielded satisfactory quantitation of β-aminopropionitrile present. Utilization of [14C]nitrile-labeled β-aminopropionitrile and concurrent analysis of cyanoacetic acid allowed almost complete accountability of BAPN added to isolated rat liver. 相似文献
32.
1. Some of the individual members of the polymeric series of proteins from human haptoglobin types 2-1 and 2-2 were isolated by gel electrophoresis. By reacting this purified material with less than an equivalent amount of hemoglobin and analyzing the result by electrophoresis, the number of haptoglobin-hemoglobin complexes could be clearly counted. For the haptoglobin 2-1 series, the number of complexes formed was n+1, where n is the serial order, in decreasing electrophoretic mobility, of the haptoglobin polymeric form used. For the haptoglobin 2-2 series, the number of complexes was n+2. 2. For the first three members of haptoglobin 2-1 series, the haptoglobin-hemoglobin composition of the complexes was estimated from scans of the unstained gels. The data indicated that this series consists of 2,3,4... alpha beta haptoglobin subunits, each of which can combine with an alpha beta subunit of hemoglobin. 相似文献
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37.
Vikki Ho Sarah Peacock Thomas E. Massey Roger W. Godschalk Frederik J. van Schooten Janet E. Ashbury 《Biomarkers》2013,18(8):735-741
AbstractPurpose: Examine the association between bulky DNA adduct levels in colon mucosa and colorectal adenoma prevalence, and explore the correlation between adduct levels in leukocytes and colon tissue.Methods: Bulky DNA adduct levels were measured using 32P-postlabelling in biopsies of normal-appearing colon tissue and blood donated by 202 patients. Multivariable logistic regression was used to examine associations between DNA adducts, and interactions of DNA adduct-DNA repair polymorphisms, with the prevalence of colorectal adenomas. Correlation between blood and tissue levels of DNA adducts was evaluated using Spearman’s correlation coefficient.Results: An interaction between bulky DNA adduct levels and XPA rs1800975 on prevalence of colorectal adenoma was observed. Among individuals with lower DNA repair activity, increased DNA adduct levels were associated with increased colorectal adenoma prevalence (OR?=?1.41 per SD increase, 95%CI: 0.92–2.18). Conversely, among individuals with normal DNA activity, an inverse association was observed (OR?=?0.60 per SD increase, 95%CI: 0.34–1.07). Blood and colon DNA adduct levels were inversely correlated (ρ?=??0.20).Conclusions: Among genetically susceptible individuals, higher bulky DNA adducts in the colon was associated with the prevalence of colorectal adenomas. The inverse correlation between blood and colon tissue measures demonstrates the importance of quantifying biomarkers in target tissues. 相似文献
38.
Narisara Chantratita Sarunporn Tandhavanant Nicolle D. Myers Sudeshna Seal Arkhom Arayawichanont Aroonsri Kliangsa-ad Lauren E. Hittle Robert K. Ernst Mary J. Emond Mark M. Wurfel Nicholas P. J. Day Sharon J. Peacock T. Eoin West 《PloS one》2013,8(11)
B. pseudomallei is a gram-negative bacterium that causes the tropical infection melioidosis. In northeast Thailand, mortality from melioidosis approaches 40%. As exemplified by the lipopolysaccharide-Toll-like receptor 4 interaction, innate immune responses to invading bacteria are precipitated by activation of host pathogen recognition receptors by pathogen associated molecular patterns. Human melioidosis is characterized by up-regulation of pathogen recognition receptors and pro-inflammatory cytokine release. In contrast to many gram-negative pathogens, however, the lipopolysaccharide of B. pseudomallei is considered only weakly inflammatory. We conducted a study in 300 healthy Thai subjects to investigate the ex vivo human blood response to various bacterial pathogen associated molecular patterns, including lipopolysaccharide from several bacteria, and to two heat-killed B. pseudomallei isolates. We measured cytokine levels after stimulation of fresh whole blood with a panel of stimuli. We found that age, sex, and white blood cell count modulate the innate immune response to B. pseudomallei. We further observed that, in comparison to other stimuli, the innate immune response to B. pseudomallei is most highly correlated with the response to lipopolysaccharide. The magnitude of cytokine responses induced by B. pseudomallei lipopolysaccharide was significantly greater than those induced by lipopolysaccharide from Escherichia coli and comparable to many responses induced by lipopolysaccharide from Salmonella minnesota despite lower amounts of lipid A in the B. pseudomallei lipopolysaccharide preparation. In human monocytes stimulated with B. pseudomallei, addition of polymyxin B or a TLR4/MD-2 neutralizing antibody inhibited the majority of TNF-α production. Challenging existing views, our data indicate that the innate immune response to B. pseudomallei in human blood is largely driven by lipopolysaccharide, and that the response to B. pseudomallei lipopolysaccharide in blood is greater than the response to other lipopolysaccharide expressing isolates. Our findings suggest that B. pseudomallei lipopolysaccharide may play a central role in stimulating the host response in melioidosis. 相似文献
39.
Direk Limmathurotsakul David A. B. Dance Vanaporn Wuthiekanun Mirjam Kaestli Mark Mayo Jeffrey Warner David M. Wagner Apichai Tuanyok Heiman Wertheim Tan Yoke Cheng Chiranjay Mukhopadhyay Savithiri Puthucheary Nicholas P. J. Day Ivo Steinmetz Bart J. Currie Sharon J. Peacock 《PLoS neglected tropical diseases》2013,7(3)
Background
Burkholderia pseudomallei, a Tier 1 Select Agent and the cause of melioidosis, is a Gram-negative bacillus present in the environment in many tropical countries. Defining the global pattern of B. pseudomallei distribution underpins efforts to prevent infection, and is dependent upon robust environmental sampling methodology. Our objective was to review the literature on the detection of environmental B. pseudomallei, update the risk map for melioidosis, and propose international consensus guidelines for soil sampling.Methods/Principal Findings
An international working party (Detection of Environmental Burkholderia pseudomallei Working Party (DEBWorP)) was formed during the VIth World Melioidosis Congress in 2010. PubMed (January 1912 to December 2011) was searched using the following MeSH terms: pseudomallei or melioidosis. Bibliographies were hand-searched for secondary references. The reported geographical distribution of B. pseudomallei in the environment was mapped and categorized as definite, probable, or possible. The methodology used for detecting environmental B. pseudomallei was extracted and collated. We found that global coverage was patchy, with a lack of studies in many areas where melioidosis is suspected to occur. The sampling strategies and bacterial identification methods used were highly variable, and not all were robust. We developed consensus guidelines with the goals of reducing the probability of false-negative results, and the provision of affordable and ‘low-tech’ methodology that is applicable in both developed and developing countries.Conclusions/Significance
The proposed consensus guidelines provide the basis for the development of an accurate and comprehensive global map of environmental B. pseudomallei. 相似文献40.
Cherry Lim Prapass Wannapinij Lisa White Nicholas P. J. Day Ben S. Cooper Sharon J. Peacock Direk Limmathurotsakul 《PloS one》2013,8(11)