Analysis Of Reaction Products Research Articles

Association of the SLC11A1 Gene Polymorphisms With Susceptibility to Mycobacterium Infections in a Japanese Population

Abstract Genetic factors may be involved in the susceptibility to mycobacterium infection. We studied the association of polymorphisms in the candidate gene, SLC11A1 (solute carrier family 11 member 1; formerly NRAMP1), which controls immune reactions to intracellular pathogens, with susceptibility to active Mycobacterium tuberculosis and nontuberculous mycobacterium infections in a Japanese population, who was admitted to a local hospital in the Kanagawa prefecture. A case-control study was performed by comparing the frequency of polymorphisms in the SLC11A1 gene in patients with pulmonary tuberculosis (57 cases) or with Mycobacterium avium-intracellulare infection (17 cases) and ethnically matched healthy controls (51 cases). Three SLC11A1 genetic polymorphisms, G/C at intron 4 (496+14G/C), transformation of aspartic acid to asparagine at 543 codon (D543N), and TGTG deletion in 3′ untranslated region (1729+55del4) were examined, using restriction fragment length polymorphism analysis of polymerase chain reaction products. The polymorphism of D543N wasfound closely associated with both pulmonary tuberculosis (P = 0.009) and M. avium-intracellulare infection (P = 0.01). The polymorphism of intron 4 was closely associated only with pulmonary tuberculosis (P = 0.05). The polymorphisms in SLC11A1 may partly explain the susceptibility to active M. tuberculosis and M. avium-intracellulare infections without predisposing factors in a Japanese population.

Antioxidation Mechanism Studies of Caffeic Acid: Identification of Antioxidation Products of Methyl Caffeate from Lipid Oxidation

As a part of a research project on the elucidation of the chain-breaking antioxidation mechanism of natural phenols in food components, caffeic acid, a polyphenolic acid widely distributed in edible plants, was investigated. The identification and time course analysis of the antioxidation reaction products from methyl caffeate were carried out in the ethyl linoleate oxidation system. The antioxidation reaction produced a quinone derivative of methyl caffeate as an antioxidation product during the initial stage, which was identified by (13)C NMR. The quinone, however, was not the final product, and a further reaction occurred to produce several new peroxides. The isolation and structure determination of the peroxides revealed that they had tricyclic structures, which consisted of ethyl linoleate, methyl caffeate, and molecular oxygen. On the basis of the formation pathway of these products, an antioxidation reaction mechanism of methyl caffeate, including the redox reaction of the caffeate and Diels-Alder reaction of the produced peroxides, was proposed.

Prevalence, disease associations and risk factors for colonization with intestinal spirochaetes (Brachyspira spp.) in flocks of laying hens in north-eastern Italy

The present study investigated the occurrence of anaerobic intestinal spirochaetes of the genus Brachyspira in laying hen flocks in Treviso province, north-eastern Italy, with respect to prevalence, spirochaete species present, disease associations and risk factors for colonization. A total of 450 faecal samples from 45 sheds on 29 laying hen farms were cultured for intestinal spirochaetes. Nineteen sheds on 12 farms contained chickens with symptoms consistent with avian intestinal spirochaetosis, including reduced egg production, wet litter and/or pasty vents. Spirochaetes were isolated from 157 (34.8%) samples from 21 (72.4%) farms, and from 32 (71.1%) sheds. From these positive samples, 189 spirochaetal isolates were speciated using three polymerase chain reaction assays and a restriction fragment polymorphism analysis of 16S rDNA polymerase chain reaction products. Overall, 52 (27.5%) isolates were identified as pathogenic Brachyspira intermedia, 26 (13.8%) as pathogenic Brachyspira pilosicoli, 93 (49.7%) as non-pathogenic (Brachyspira innocens/Brachyspira murdochii), and 18 (9.6%) were unidentified. Faeces from 14 sheds (31%) on 10 farms (34.5%) contained B. intermedia and/or B. pilosicoli, and disease consistent with avian intestinal spirochaetosis was observed in nine of these sheds on seven farms. There was a significant association (P=0.042) between the presence of spirochaetes and using deep pits rather than conveyor belts for manure disposal. Sheds housing chickens >40 weeks of age were significantly more likely to contain spirochaetes (P=0.048) and pathogenic species (P=007) than sheds housing younger chickens. A significant association (P=0.02) was found between infection with pathogenic spirochaetes and reduced egg production.

Kinetics and Ligand-Binding Preferences of Mycobacterium tuberculosis Thymidylate Synthases, ThyA and ThyX

Background Mycobacterium tuberculosis kills approximately 2 million people each year and presents an urgent need to identify new targets and new antitubercular drugs. Thymidylate synthase (TS) enzymes from other species offer good targets for drug development and the M. tuberculosis genome contains two putative TS enzymes, a conventional ThyA and a flavin-based ThyX. In M. tuberculosis, both TS enzymes have been implicated as essential for growth, either based on drug-resistance studies or genome-wide mutagenesis screens. To facilitate future small molecule inhibitors against these proteins, a detailed enzymatic characterization was necessary.Methodology/Principal FindingsAfter cloning, overexpression, and purification, the thymidylate-synthesizing ability of ThyA and ThyX gene products were directly confirmed by HPLC analysis of reaction products and substrate saturation kinetics were established. 5-Fluoro-2′-deoxyuridine 5′-monophosphate (FdUMP) was a potent inhibitor of both ThyA and ThyX, offering important clues to double-targeting strategies. In contrast, the folate-based 1843U89 was a potent inhibitor of ThyA but not ThyX suggesting that it should be possible to find ThyX-specific antifolates. A turnover-dependent kinetic assay, combined with the active-site titration approach of Ackermann and Potter, revealed that both M. tuberculosis enzymes had very low k cat values. One possible explanation for the low catalytic activity of M. tuberculosis ThyX is that its true biological substrates remain to be identified. Alternatively, this slow-growing pathogen, with low demands for TMP, may have evolved to down-regulate TS activities by altering the turnover rate of individual enzyme molecules, perhaps to preserve total protein quantities for other purposes. In many organisms, TS is often used as a part of larger complexes of macromolecules that control replication and DNA repair.Conclusions/SignificanceThus, the present enzymatic characterization of ThyA and ThyX from M. tuberculosis provides a framework for future development of cell-active inhibitors and the biological roles of these TS enzymes in M. tuberculosis.

Tn5 mutants of Bradyrhizobium japonicum Is-1 with altered compatibility with Rj 2-soybean cultivars

Bradyrhizobium japonicum Is-1 is incompatible with soybean (Glycine max L. Merr.) cv. CNS (Rj 2 Rj 3) and compatible with cv. Hill (Rj 4) and is, therefore, classified into nodulation-type B. Tn5 mutants (1C1, 1C2, 5C1, 6C1, 7C1, 7C2, 10C1 and 10C2) were isolated from eight nodules produced on CNS that had been inoculated with the kanamycin-resistant (Kmr) transconjugants of strain Is-1. To investigate the shift of host range, Tn5 mutants were inoculated to soybean cvs. CNS, D-51 (Rj 3), Hardee (Rj 2 Rj 3), Hill and IAC-2 (Rj 2 Rj 3). They acquired the ability to nodulate Rj 2 Rj 3 soybeans without losing the ability to nodulate both Rj 3 and Rj 4. These results suggest that the Tn5 mutation in B. japonicum strain Is-1 is only related to the ability to nodulate Rj 2 soybean. Although the host ranges were common to Tn5 mutants and all sections of nodules produced by Tn5 mutants indicate a red color, the nodule numbers and nitrogen fixation activities were different for each mutant. These results suggest that Tn5 insertion sites are different from each other. Tn5-flanking sequences in these mutants were specifically amplified. The electrophoresis analyses of the polymerase chain reaction (PCR) products showed that Tn5 mutants contained a single copy of Tn5, except for 10C1. These PCR products were cloned and sequenced. The sequence analysis of Tn5-flanking sequences revealed that these Tn5 insertion sites were different from each other and all homologous sequences to them were found in the complete genome sequence of B. japonicum USDA 110. These results are in good accordance with our expectation that Tn5 insertion sites are different for each mutant. Most Tn5-inserted gene products relate to the cell membrane structure. This suggests that the change in the cell surface structure in Tn5 mutants may overcome nodulation restriction conditioned by Rj 2 soybean.

Arsenite sorption at the magnetite–water interface during aqueous precipitation of magnetite: EXAFS evidence for a new arsenite surface complex

The interaction of aqueous As(III) with magnetite during its precipitation from aqueous solution at neutral pH has been studied as a function of initial As/Fe ratio. Arsenite is sequestered via surface adsorption and surface precipitation reactions, which in turn influence the crystal growth of magnetite. Sorption samples were characterized using EXAFS spectroscopy at the As K-edge in combination with HRTEM observations, energy dispersive X-ray analysis at the nanoscale, electron energy loss spectroscopy at the Fe L 3-edge, and XRD-Rietveld analyses of reaction products. Our results show that As(III) forms predominantly tridentate hexanuclear As(III)O 3 complexes ( 3 C), where the As(III)O 3 pyramids occupy vacant tetrahedral sites on {1 1 1} surfaces of magnetite particles. This is the first time such a tridentate surface complex has been observed for arsenic. This complex, with a dominant As–Fe distance of 3.53 ± 0.02 Å, occurs in all samples examined except the one with the highest As/Fe ratio (0.33). In addition, at the two highest As/Fe ratios (0.133 and 0.333) arsenite tends to form mononuclear edge-sharing As(III)O 3 species ( 2 E) within a highly soluble amorphous As(III)–Fe(III,II)-containing precipitate. At the two lowest As/Fe ratios (0.007 and 0.033), our results indicate the presence of additional As(III) species with a dominant As–Fe distance of 3.30 ± 0.02 Å, for which a possible structural model is proposed. The tridentate 3 C As(III)O 3 complexes on the {1 1 1} magnetite surface, together with this additional As(III) species, dramatically lower the solubility of arsenite in the anoxic model systems studied. They may thus play an important role in lowering arsenite solubility in putative magnetite-based water treatment processes, as well as in natural iron-rich anoxic media, especially during the reductive dissolution-precipitation of iron minerals in anoxic environments.

Effect of the Spilt-Over Hydrogen Species on the Product Yields of the Hybrid Catalysts Used in the Thermocatalytic Cracking (TCC) Process for the Production of Light Olefins

The supported Ni co-catalyst surface of the thermocatalytic cracking (TCC) hybrid catalyst produces very active hydrogen species. Such species, once transferred (spilt-over) onto the surface of the main catalyst component (cracking sites), interact with the adsorbed reaction intermediates, resulting in a decreased formation of coke precursors (polynuclear aromatics) and the dearomatization/ring-opening of some heavy compounds of the feed. Simultaneously, there is a significant increase in the product yields of light olefins, particularly ethylene and propylene. Analysis of reaction products after 10 h of continuous reaction shows the very significant effects of these co-catalysts on heavy feedstocks such as vacuum gas oils, although the amounts of these (spilt-over) hydrogen species are very small, in comparison to the molecular hydrogen produced by the cracking reactions.

Photocatalytic Removal of Pesticide Dichlorvos from Indoor Air: A Study of Reaction Parameters, Intermediates and Mineralization

This paper presents for the first time the investigation of TiO2 photocatalysis for the removal of pesticides in gas phase. Dichlorvos was used as a model pesticide, and experiments were carried out using both static and dynamic reaction systems to explore the different aspects of the process. Thus, adsorption, reaction kinetics, and the influence of several operational parameters such as relative humidity (RH), inlet concentration, flow rate, and association of TiO2 with activated carbon (AC) were all examined in detail. Furthermore, a special attention was devoted to the analysis of reaction products by means of various analytical techniques such as Fourier transform infrared spectroscopy, automated thermal desorption technique coupled to gas chromatography-mass spectrometry instrument, gas chromatography equipped with a pulse discharge helium photoionization detector, and ion chromatography. The results showed an immediate and total removal of dichlorvos at ppbv levels (50-350 ppbv) along with a high mineralization extent (50-85%) into harmless final products (CO2, HCl, PO43-). Moreover, RH was found to significantly affectthe mineralization extent and the formation of reaction intermediates. On the basis of identification data, direct charge transfer and chlorine radical (Cl*) attack were shown to play a key role in the reaction mechanism at low RH, whereas at high RH, HO* radicals were the predominant active species.

Coupled redox transformations of catechol and cerium at the surface of a cerium(III) phosphate mineral

Highly insoluble Ce-bearing phosphate minerals form by weathering of apatite [Ca5(PO4)3.(OH,F,Cl)], and are important phosphorous repositories in soils. Although these phases can be dissolved via biologically-mediated pathways, the dissolution mechanisms are poorly understood. In this paper we report spectroscopic evidence to support coupling of redox transformations of organic carbon and cerium during the reaction of rhabdophane (CePO4·H2O) and catechol, a ubiquitous biogenic compound, at pH 5. Results show that the oxic–anoxic conditions influence the mineral dissolution behavior. Under anoxic conditions, the release of P and Ce occurs stoichiometrically. In contrast, under oxic conditions, the mineral dissolution behavior is incongruent, with dissolving Ce3+ ions oxidizing to CeO2. Reaction product analysis shows the formation of CO2, polymeric C, and oxalate and malate. The presence of more complex forms of organic carbon was also confirmed. Near edge X-ray absorption fine structure spectroscopy measurements at Ce-M4,5 and C-K absorption edges on reacted CePO4·H2O samples in the absence or presence of catechol and dissolved oxygen confirm that (1) the mineral surface converts to the oxide during this reaction, while full oxidation is limited to the near-surface region only; (2) the Ce valence remains unchanged when the reaction between CePO4·H2O and O2 but in the absence of catechol. Carbon K-edge spectra acquired from rhabdophane reacted with catechol under oxic conditions show spectral features before and after reaction that are considerably different from catechol, indicating the formation of more complex organic molecules. Decreases in intensity of characteristic catechol peaks are accompanied by the appearance of new π∗ resonances due to carbon in carboxyl (ca. 288.5eV) and carbonyl (ca. 289.3eV) groups, and the development of broad structure in the σ∗ region characteristic of aliphatic carbon. Evolution of the C K-edge spectra is consistent with aromatic-ring cleavage and polymerization. These results further substantiate that the presence of catechol, O2 (aq) causes both the oxidation of structural Ce3+ and the transformation of catechol to more complex organic molecules. Scanning Transmission X-Ray Microscopy measurements at the C K and Ce M4,5 edges indicate three dominant organic species, varying in complexity and association with the inorganic phase. Untransformed catechol is loosely associated with CeO2, whereas more complex organic molecules that exhibit lower aromaticity and stronger CO π∗ resonances of carboxyl-C and carbonyl-C groups are only found in association with the grains. These results further serve as basis to postulate that, in the presence of O2, CeO2 can mediate the oxidative polymerization of catechol to form higher molecular weight polymers. The present work provides evidence for a pathway of biologically-induced, non-enzymatic oxidation of cerium and formation of small CeO2 particles at room temperature. These findings may have implications for carbon cycling in natural and cerium-contaminated soils and aqueous environments.

Purification and physicochemical properties of - amylase from cockroach, Periplaneta americana (LINNAEUS), for starches saccharification

An
-amylase was purified from the American cockroach Periplaneta americana (Linnaeus) to homogeneity by four steps purification via ammonium sulphate crude extract precipitation, Sephacryl S-100 HR gel permeation chromatography, anion exchange chromatography on DEAE-Sepharose CL-6B and hydrophobic interaction chromatography on phenyl Sepharose CL-4B. The purification was approximatively 38.42 fold with a 24.31% yield. Optimums pH and temperature of the purified
-amylase were found to be 5.6 and 55°C, respectively. The enzyme was stable up to 55°C and its pH stability was in range of 5.6 - 6.6. The KM and Vmax of the enzyme with soluble starch as substrate were 5 mg/ml and 100 imol/min/mg, respectively, and the energy of activation (Ea), was 50.32 Kj/mol. The
-amylase was inhibited by Tris, Fe3+, Ba2+, Mo+ and EDTA. While Ca2+, K+, Cu2+, Mg2+ and para-hydroxymercuribenzoate (pHMB) activated the enzyme. Analysis of the amylolytic reaction products by HPLC showed the presence of maltose and maltodextrin but not glucose in the starch hydrolysate (2 h of reaction). This result indicated that the amylolytic enzyme of P. americana is an
-amylase (an endoamylase). The purified
-amylase hydrolysed maltopentose, maltohexose and maltoheptose. Maltose, maltotriose and maltotetrose were not hydrolysed by this enzyme. Therefore, the purified
-amylase is active only on substrates with more than four residues of glucose.

Molecular and cytogenetic evidence of three sibling species of the Anopheles barbirostris Form A (Diptera:Culicidae) in Thailand

Nine isoline colonies of Anopheles barbirostris Form A, derived from individual isofemale lines from Chiang Mai, Phetchaburi, and Kanchanaburi, were established in our insectary at Chiang Mai University. All isolines shared the same mitotic karyotype (X(1), X(2), Y(1)). Molecular analysis of deoxyribonucleic acid (DNA) sequences and polymerase chain reaction (PCR) products of ITS2, COI, and COII regions revealed three distinct groups: A1 (Chiang Mai), A2 (Phetchaburi), and A3 (Kanchanaburi). Crossing experiments among the three groups exhibited strong reproductive isolation, producing low and/or non-hatched eggs, and inviable and/or abnormal development of the reproductive system of F(1)-progenies. Asynaptic regions along the five polytene chromosome arms of F(1)-hybrid larvae clearly supported the existence of three sibling species within A. barbirostris Form A, provisionally named species A1, A2, and A3.

Genetic Polymorphisms and Haplotype Structures of the Human CYP2W1 Gene in a Japanese Population

A novel human cytochrome P450, designated CYP2W1, has recently been identified and is found to be present mainly in tumor cells, particularly in colon cancer cells. In the present study, we report the first systematic investigation of polymorphisms in the human CYP2W1 gene. Based on denaturing high performance liquid chromatography analyses of polymerase chain reaction products, we analyzed nine exons and exon-intron junctions of the gene in DNA samples from 200 Japanese subjects and identified six single nucleotide polymorphisms (SNP). Three of the novel nonsynonymous SNPs were as follows: 173A>C (Glu58Ala) in exon 1 and 5432G>A (Val432Ile) and 5584G>C (Gln482His) in exon 9. Two previously known nonsynonymous SNPs, that is, 2008G>A (Ala181Thr) in exon 4 and 5601C>T (Pro488Leu) in exon 9, were also found. On haplotype analyses, in addition to the wild-type CYP2W1*1A (frequency, 0.295) allele, other alleles, namely, CYP2W1*1B (0.318), CYP2W1*2 (0.005), CYP2W1*3 (0.005), CYP2W1*4 (0.008), CYP2W1*5 (0.003), and CYP2W1*6 (0.368), were also characterized. The most common allele, CYP2W1*6, exhibited the amino acid substitution Pro488Leu. These results were in good agreement with the expected genotype distributions that were calculated using the Hardy-Weinberg equation. The data on variant alleles and comprehensive haplotype structures would be useful for predicting the metabolic phenotypes of CYP2W1 substrates in the Japanese population.

Non‐invasive monitoring of oxidative skin stress by ultraweak photon emission (UPE)‐measurement. I: mechanisms of UPE of biological materials

Oxidation of proteins and amino acids is associated with generation of ultraweak photon emission (UPE), which may be used to assess oxidative processes in the skin in a non-invasive way. This first part of a series of reports addresses the physicochemical basis of oxidation-induced UPE in the skin, with a special focus on the contribution of amino acid oxidation. UPE of biological samples and protein/amino acid solutions following oxidation with H(2)O(2) in the presence of Fe(2+) was recorded using a sensitive photomultiplier system. Signals were analyzed with regard to overall signal intensity and spectral distribution. Increasing concentrations of H(2)O(2) in aqueous bovine serum albumin solutions induced linearly correlated UPE and protein carbonyl compounds, with a substantially higher sensitivity for the measurement of UPE. In single amino acid solutions, strong UPE signals were generated by oxidation from Phe, Trp, His, and Cys, and weak signals from Lys and Thr. Analysis of reaction products by MS revealed high oxidative material turnover for Cys and His, whereas barely detectable oxidative material turnover seems to be sufficient to generate a UPE signal of similar strength from Trp and Phe. Combination of different amino acids did not result in a simple addition of individual oxidation-induced UPE signals, but in interactions ranging from antagonism to clear synergism. Synergism was evident between Trp- and UPE-generating amino acids such as Thr, Cys, and His, with the strongest synergism by far observed between Trp and His. The strikingly different individual UPE spectra of His and Trp, despite being of comparable overall strength, were congruent with a pure Trp UPE spectrum after combining His with Trp in solution, indicating energy transfer between both amino acids. Combination of Trp and DNA, which also gives UPE signals following oxidation, did not result in a synergistically enhanced or antagonized overall UPE signal, but in a simple addition of individual UPE signals. Measurement of UPE could be proven to be a highly sensitive method to assess oxidative processes in biological molecules. The reported data indicate that UPE generated by oxidation stressed skin is mainly due to non-fluorescent photon emission via Trp, whereby Trp acts as an energy receptor from other excited species of oxidation-modified amino acids.

BRAF mutations in melanocytic lesions and papillary thyroid carcinoma samples identified using melting curve analysis of polymerase chain reaction products.

Abstract Context.—Mutations of the proto-oncogene B-raf (BRAF) have been detected in melanocytic lesions and papillary carcinomas of the thyroid, and identification of these mutations could be useful in resolving some diagnostic problems. Objective.—To develop a method to evaluate mutations of BRAF that could provide results much more rapidly than conventional polymerase chain reaction and DNA sequencing assays. Design.—An assay using a LightCycler was developed to evaluate DNA sequences encoding amino acids within the activation loop of BRAF. Results.—Using this real-time polymerase chain reaction method, we analyzed 55 paraffin-embedded melanoma or nevus samples. The V600E mutation was found in 0 (0%) of 13 samples diagnosed histologically as Spitz nevi, 9 (24.3%) of 37 invasive melanomas, and 5 (100%) of 5 other melanocytic nevi. Two additional mutations, V600K and VK600-1E, also were identified in cases of invasive melanoma. We analyzed 14 paraffin-embedded papillary thyroid cancer (PTC) samples, 6 of...

Single molecule analysis of bacterial polymerase chain reaction products in submicrometer fluidic channels

Laser induced fluorescence in submicrometer fluidic channels was used to characterize the synthesis of polymerase chain reaction (PCR) products from a model bacterial system in order to explore the advantages and limitations of on chip real time single molecule PCR analysis. Single oligonucleotide universal bacterial primers and PCR amplicons from the 16S rDNA of Thermobifida fusca (325 bp) were directly detected at all phases of the reaction with low sample consumption and without post-amplification purification or size screening. Primers were fluorescently labeled with single Alexa Fluor 488 or Alexa Fluor 594 fluorophores, resulting in double labeled, two color amplicons. PCR products were driven electrokinetically through a fused silica channel with a 250 nm by 500 nm rectangular cross section. Lasers with 488 nm and 568 nm wavelengths were focused and overlapped on the channel for fluorescence excitation. All molecules entering the channel were rapidly and uniformly analyzed. Photon burst analysis was used to detect and identify individual primers and amplicons, and fluorescence correlation and cross-correlation spectroscopy were used to account for analyte flow speed. Conventional gel and capillary electrophoresis were also used to characterize the PCR amplification, and the results of differences in detection sensitivity and analyte discrimination were examined. Limits were imposed by the purity and labeling efficiency of the PCR reagents, which must be improved in parallel with increases in detection sensitivity.

Analysis of NPM1 Gene Mutations in Chinese Adults with Acute Myeloid Leukemia

Many European groups have recently described that mutations at exon-12 of the nucleophosmin (NPM1) gene are the most frequent genetic lesion in patients with acute myeloid leukemia (AML), especially in the presence of a normal karyotype. This study explored the prevalence and clinical profile of NPM1 mutations in a cohort of 156 Chinese adults with AML. NPM1 exon-12 mutations were detected using direct sequencing or fragment analysis of genomic DNA polymerase chain reaction products. NPM1 mutations were present in 28.2% of the overall population, including 1/1 (100%) of M0, 11/27 (40.7%) of M1, 11/46 (23.9%) of M2, 0/29 (0%) of M3, 2/9 (22.2%) of M4, 18/39 (46.2%) of M5, and 1/5 (20.0%) of M6. NPM1 gene mutations were more prevalent in patients with a normal karyotype (37 of 90; 41.1%) when compared with patients with karyotypic abnormalities (7 of 66; 10.6%;P < .001). Sequence analysis of 25 NPM1-mutated cases revealed known mutations (type A, D, N(M), and P(M)) as well as one novel sequence variation (here named as type S). All mutational types were heterozygous and showed a 4 bp insertion. NPM1 mutations were significantly associated with old age (P < .05), high peripheral white blood cell count (P < .05), and the subtypes of French-American-British categories M1/M5, but negatively associated with expression of CD34 (P < .05) and CD117 (P < .05). Thus, this study provides the methods of NPM1 exon-12 mutations detection and related clinical data of NPM1 mutated cases in a Chinese population.

A variant of position −308 of the Tumour necrosis factor alpha gene promoter and the risk of coronary heart disease

The aim of this study was to investigate whether the variability between individuals with coronary heart disease (CHD) is related to the prevalence of TNF-alpha gene promoter -308 variant in un-matched British Caucasian population from East Midlands. Genotypes and allele frequencies were determined using restriction fragment length polymorphism analysis of polymerase chain reaction (PCR) products. Genomic DNA prepared from peripheral blood leukocytes of patients (n=97) and healthy controls (n=95) demonstrated two alleles TNF*1 (G) and TNF*2 (A). The genotype distribution in patients was GG, n=59; GA, n=36; and AA, n=2 and in controls was GG, n=41; GA, n=40; and AA, n=14 (P=0.014). The association analysis demonstrated that TNF*1 allele in patients appears to be associated with greater incidences of CHD (OR 2.15; CI, 1.36-3.39; P=0.001). Our results suggest that TNF*1 allele (TNF-alpha -308 GG or GA) has a high prevalence among British Caucasian population that correlates with an increased CHD risk.

Investigations into the kinetics and mechanism of gas–solid state processes in MgO–MgR 2O 4 (R: Al, Cr, Fe) spinels–SO 2–O 2 system

In refractory ceramics magnesia-spinel materials continue to play an important role for both economic and research reasons. Although their basic properties are considered to be well-known, problems connected with production technology and improvement of application remain to be solved. The aim of this work is to describe and explain the behaviour of spinels in gaseous environment having high concentration of sulfur oxides. Thermodynamic analysis of chemical reactions in MgO–MgR 2O 4 (R: Al, Cr, Fe) spinels–SO 2–O 2 system as well as kinetic investigations and phase analysis of reaction products were carried out. Kinetic investigation results enabled to compare the chemical reactivity of spinels: MgAl 2O 4, MgCr 2O 4, MgFe 2O 4 and MgO at temperature 773, 1073 and 1273 K. On the basis of shrinking core model activation energy of the reaction MgO + SO 3 → MgSO 4 was calculated. Kinetic measurements confirmed the influence of early suggested phase changes on chemical reactivity of spinels within characteristic temperature range and revealed unexpectedly high reactivity of MgFe 2O 4 in comparison with the other spinels and MgO. It points out the criteria of selecting raw materials in basic refractory ceramics.

The reactions and composition of the surface intermediate species in the selective catalytic reduction of NO x with ethylene over Co-ZSM-5

A pretreatment-transient reaction product analysis method was applied to study the reactions and average composition of the possible surface intermediate species in selective catalytic reduction with ethylene of NOx over Co-ZSM-5. The reactions of the surface species, formed by the pretreatment of Co-ZSM-5 in a NO/C2H4/O2 mixture at 275°C, with the NO/O2 flow produced much more N2 than that with the individual NO or O2 flow. The similarity of N2/COx/H2O product distribution generated from the above surface species-NO/O2 reactions and that from the normal NO/C2H4/O2 flow reactions implies that the surface species NCaObHc formed in the three-component pretreatment process is very likely the primary intermediate surface species generated during the real flow reactions. The in situ FT-IR (DRIFT) spectroscopy measurements of the surface species support the above conclusion.

Atmospheric oxalic acid and SOA production from glyoxal: Results of aqueous photooxidation experiments

Aqueous-phase photooxidation of glyoxal, a ubiquitous water-soluble gas-phase oxidation product of many compounds, is a potentially important global and regional source of oxalic acid and secondary organic aerosol (SOA). Reaction kinetics and product analysis are needed to validate and refine current aqueous-phase mechanisms to facilitate prediction of in-cloud oxalic acid and SOA formation from glyoxal. In this work, aqueous-phase photochemical reactions of glyoxal and hydrogen peroxide were conducted at pH values typical of clouds and fogs (i.e., pH=4–5). Experimental time series concentrations were compared to values obtained using a published kinetic model and reaction rate constants from the literature. Experimental results demonstrate the formation of oxalic acid, as predicted by the published aqueous phase mechanism. However, the published mechanism did not reproduce the glyoxylic and oxalic acid concentration dynamics. Formic acid and larger multifunctional compounds, which were not previously predicted, were also formed. An expanded aqueous-phase oxidation mechanism for glyoxal is proposed that reasonably explains the concentration dynamics of formic and oxalic acids and includes larger multifunctional compounds. The coefficient of determination for oxalic acid prediction was improved from 0.001 to >0.8 using the expanded mechanism. The model predicts that less than 1% of oxalic acid is formed through the glyoxylic acid pathway. This work supports the hypothesis that SOA forms through cloud processing of glyoxal and other water-soluble products of alkenes and aromatics of anthropogenic, biogenic and marine origin and provides reaction kinetics needed for oxalic acid prediction.