bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conversion of linoleic acid into novel oxylipins by the mushroom Agaricus bisporus
Authors: Wadman Mayken W. , van Zadelhoff Guus , Hamberg Mats , Visser Tom , Veldink Gerrit A. , Vliegenthart Johannes F. G. 
Published: November 2006

AbstractOxylipins are associated with important processes of the fungal life cycle, such as spore formation. Here, we report the formation of FA metabolites in Agaricus bisporus. Incubation of a crude extract of lamellae with linoleic acid (18∶2) led to the extensive formation of two oxylipins. They were identified as 8(R)‐hydroxy‐9Z,12Z‐octadecadienoic acid (8‐HOD) and 8(R),11(S)‐dihydroxy‐9Z,12Z‐octadecadienoic acid (8,11‐diHOD) by using RP‐HPLC, GC‐MS, IR, GC‐MS analysis of diastereomeric derivatives, and 1H NMR and 13C NMR spectroscopy. Neither compound has been reported before in A. bisporus. Oleic (18∶1), α‐linolenic (18∶3n−3), and γ‐linolenic (18∶3n−6) acids were converted into their 8‐hydroxy derivatives as well, and 18∶3n−3 was further metabolized to its 8,11‐diol derivative. Reactions with [U‐13C]18∶2 demonstrated that the compounds 8‐HOD and 8,11‐diHOD were formed from exogenously supplied 18∶2. When [U‐13C]8‐HOD was supplied, it was not converted into 8,11‐diHOD, indicating that it was not an intermediate in the formation of 8,11‐diHOD. When a crude extract of A. bisporus was incubated under an atmosphere of 16O2/18O2, the two hydroxyl groups of 8,11‐diHOD contained either two 18O atoms or two 16O atoms. Species that contained one of each isotope could not be detected. We propose that the formation of the 8,11‐dihydroxy compounds occurs through either an 8,11‐endoperoxy, an 8‐peroxo free radical, or an 8‐hydroperoxy intermediate. In the latter case, the reaction should be catalyzed by dioxygenase with novel specificity.
The fate and intermediary metabolism of stearic acid
Authors: Sampath Harini , Ntambi James M. 
Published: November 2006

AbstractComing from the Greek for “hard fat”, stearic acid represents one of the most abundant FA in the Western diet. Otherwise known as n‐octadecanoic acid (18∶0), stearate is either obtained in the diet or synthesized by the elongation of palmitate, the principal product of the FA synthase system in animal cells. Stearic acid has been shown to be a very poor substrate for TG synthesis, even as compared with other saturated fats such as myristate and palmitate, and in human studies stearic acid has been shown to generate a lower lipemic response than medium‐chain saturated FA. Although it has been proposed that this may be due to less efficient absorption of stearic acid in the gut, such findings have not been consistent. Along with palmitate, stearate is the major substrate for the enzyme stearoyl‐CoA desaturase, which catalyzes the conversion of stearate to oleate, the preferred substrate for the synthesis of TG and other complex lipids. In mice, targeted disruption of the stearoyl‐CoA desaturase‐1 (SCD1) gene results in the generation of a lean mouse that is resistant to diet‐induced obesity and insulin resistance. SCD1 also has been shown to be a key target of the anorexigenic hormone leptin, thus underscoring the importance of this enzyme, and consequently the cellular stearate‐to‐oleate ratio, in lipid metabolism and potentially in the treatment of obesity and related disorders.
Comparative effect of fenofibrate on hepatic desaturases in wild‐type and peroxisome proliferator‐activated receptor α‐deficient mice
Authors: Guillou Hervé , Martin Pascal , Jan Sophie , D'Andrea Sabine , Roulet Alain , Catheline Daniel , Rioux Vincent , Pineau Thierry , Legrand Philippe 
Published: November 2006

AbstractIn this study is presented the effect of fenofibrate, a prototypical peroxisome proliferator of the fibrate class, on wild‐type and peroxisome proliferator‐activated receptor α (PPARα)‐/‐mouse liver FA profile, desaturase mRNA levels, and activities. We established that, following peroxisome proliferator exposure, the hepatic FA profile was greatly modified. These modifications in hepatic FA content required the expression of PPARα, as they are suppressed in transgenic mice deficient in this nuclear receptor. Following peroxisome proliferator exposure, Δ6‐ and Δ5‐desaturase mRNA levels and activities were increased in wild‐type but not in PPARα‐deficient mouse liver. These results suggest the involvement of PPARα in the control of hepatic Δ6‐ and Δ5‐desaturases in mice. Their roles in minimizing long‐chain PUFA depletion in the liver during peroxisome proliferator exposure are discussed.
The bottom‐up solution to the triacylglycerol lipidome using atmospheric pressure chemical ionization mass spectrometry
Authors: Byrdwell William Craig 
Published: November 2006

AbstractPresented here is an approach to representing the data from atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) of triacylglycerols (TAG) using a set of one, two, or three Critical Ratios. These Critical Rations may be used directly to provide structural information concerning the regioisomeric composition of the triacylglycerols (TAG), and about the degree of unsaturation in the TAG. An AAA‐type, or Typel, TAG has only one Critical Ratio, the ratio of the protonated molecule, [M+H]+, to the DAG fragment ion, [AA]+. The Critical Ratio for a Type I TAG is [MH]+/Σ[DAG]+, and the mass spectrum of a Type I TAG can be reproduced from only this one ratio. An ABA/AAB/BAA, or Type II, TAG has two Critical Ratios, the [MH]+/Σ[DAG]+ ratio and the [AA]+/[AB]+ ratio. The [AA]+/[AB]+ ratio for a single TAG or TAG mixture can be compared with the [AA]+/[AB]+ ratios of pure regioisomeric standards, and the percentage of each regioisomer can be estimated. The abundance of the protonated molecule and the abundances of the two [DAG]+ fragment ions can be calculated from the two Critical Ratios for a Type II TAG. To calculate the abundances, the Critical Ratios are processed through the Bottom‐Up Solution to the TAG lipidome. First, Critical Limits are calculated from the Critical Ratios, and then the Critical Ratios are classified into Cases by comparison with the Critical Limits. Once the Case classification is known, the equation for the abundance of each ion in the mass spectrum is given by the Bottom‐Up Solution. A Type III TAG has three different FA and three Critical Ratios. The [MH]+/Σ/[DAG]+ ratio is the first Critical Ratio, the [AC]+/([AB]++[BC]+) ratio is the second Critical Ratio, and the [BC]+/[AB]+ ratio is the third Critical Ratio. The second critical ratio for a Type III TAG can be compared with regioisomeric standards to provide an estimate of the percentage composition of the regioisomers. The three Critical Ratios for a Type III TAG can be processed through the Bottom‐Up Solution to calculate the four ion abundances that make up the APCI‐MS mass spectrum. The Critical Ratios constitute a reduced data set that provides more information in fewer values than the raw abundances.
Application of supercritical fluid chromatography in the quantitative analysis of minor components (carotenes, vitamin E, sterols, and squalene) from palm oil
Authors: Choo Yuen May , Ng Mei Han , Ma Ah Ngan , Chuah Cheng Hock , Hashim Mohd Ali 
Published: November 2006

AbstractThe application of supercritical fluid chromatography (SFC) coupled with a UV variable‐wavelength detector to isolate the minor components (carotenes, vitamin E, sterols, and squalene) in crude palm oil (CPO) and the residual oil from palm‐pressed fiber is reported. SFC is a good technique for the isolation and analysis of these compounds from the sources mentioned. The carotenes, vitamin E, sterols, and squalene were isolated in less than 20 min. The individual vitamin E isomers present in palm oil were also isolated into their respective components, α‐tocopherol, α‐tocotrienol, γ‐tocopherol, γ‐tocotrienol, and δ‐tocotrienol. Calibration of all the minor components of palm as well as the individual components of palm vitamin E was carried out and was found to be comparable to those analyzed by other established analytical methods.
A semiautomated enzymatic method for determination of nonesterified fatty acid concentration in milk and plasma
Authors: Christmass Michael A. , Mitoulas Leon R. , Hartmann Peter E. , Arthur Peter G. 
Published: November 2006

AbstractAn enzymatic assay for the determination of non‐esterified fatty acid concentrations in milk and plasma is described. The procedure is semiautomated for use with a plate luminometer or plate spectrophotometer and enables routine batch processing of large numbers of small samples (≤5 μL). Following the activation of nonesterified fatty acids (NEFA) by acyl‐CoA synthetase, the current assay utilizes UDP‐glucose pyrophosphorylase to link inorganic pyrophosphate to the production of NADH through the reactions catalyzed by phosphoglucomutase and glucose‐6‐phosphate 1‐dehydrogenase. With this assay sequence the formation of NADH from NEFA is complete within 50 min at 37°C. Enzymatic spectrophotometric techniques were unsuitable for NEFA determination in human milk due to the opacity of the sample. The use of the NADH‐luciferase system has overcome this problem, allowing the enzymatic determination of NEFA in human milk. Sample collection and treatment procedures for milk and plasma have been developed to prevent enzymatic lipolysis and to limit interference from enzymes present in milk. The recovery of palmitic acid added to milk and plasma samples was 94.9±2.9 and 100±4.5%, respectively. There was no difference (P=0.13) in plasma NEFA concentrations determined by the current method and a commercially available enzymatic spectrophotometric technique (Wako NEFA‐C kit). Plasma NEFA concentrations determined by gas chromatography were 28% higher compared to both the Wako NEFA‐C kit and the current method.
Effect of tetracosahexaenoic acid on the content and release of histamine, and eicosanoid production in MC/9 mouse mast cell
Authors: Ishihara Kenji , Murata Masakazu , Kaneniwa Masaki , Saito Hiroaki , Shinohara Kazuki , Maeda‐Yamamoto Mari , Kawasaki Ken‐ichi , Ooizumi Tooru 
Published: November 2006

Abstract6,9,12,15,18,21‐Tetracosahexaenoic acid (24∶6n−3) was isolated from a brittle star,Ophiura sarsiLütken, at>95% purity to evaluate its physiological functions. The effects of 24∶6n−3 on the production of leukotriene (LT)‐related compounds such as LTB4, LTC4and 5‐hydroxyeicosatetraenoic acid, and the accumulation and release of histamine in an MC/9 mouse mast cell line were studied. We found that 24∶6n−3 could inhibit the antigen‐stimulated production of LT‐related compounds as well as other n−3 polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (20∶5n−3) and docosahexaenoic acid (22∶6n−3), which are major n−3 PUFA in fish oils; 24∶6n−3 was also shown to reduce the histamine content in MC/9 cells at 25 μM (27% reduction from the control), and the effect was diminished with increase of the fatty acid concentration (up to 100 μM). These two n−3 PUFA, 20∶5n−3 and 22∶6n−3, also reduced the histamine content (16 and 20% reduction at 25 μM, respectively), whereas arachidonic acid (20∶4n−6) increased it (18% increase at 25 μM). Spontaneous‐ and antigen‐induced release of histamine was not influenced with these PUFA (at 25 μM). Ionophore‐stimulated release of histamine was suppressed by the PUFA (13,9,15, and 11% reduction with 20∶4n−6, 20∶5n−3, 22∶6n−3, and 24∶6n−3, respectively). The patterns of the effects of 24∶6n−3 on the synthesis of eicosanoids and histamine content were more similar to those of 22∶6n−3 than 20∶5n−3. From these results, 24∶6n−3 can be expected to have anti‐inflammatory activity and antiallergic activities similar to those of 22∶6n−3.
Quantitative determination of butylated hydroxyanisole, butylated hydroxytoluene, and tert‐butyl hydroquinone in oils, foods, and biological fluids by high‐performance liquid chromatography with fluorometric detection
Authors: Yankah Vivienne V. , Ushio Hideki , Ohshima Toshiaki , Koizumi Chiaki 
Published: November 2006

AbstractConcentrations of synthetic antioxidants butylated hydroxyanisole, butylated hydroxytoluene, and tert‐butyl hydroquinone were quantified using a high‐performance liquid chromatograph with spectrofluorometric detector. The antioxidants were separated and eluted on a reversed‐phase column by gradient of a mixture of H2O/acetonitrile/acetic acid (66.5: 28.5∶5, by vol) and a mixture of acetonitrile/acetic acid (95∶5, vol/vol). The eluants were monitored at emission and excitation wavelengths of 310 and 280 nm, respectively. Calibration curves obtained using peak areas against concentration showed ligh coefficients of multiple determination (R2>0.99) for all antioxidants. Known concentrations of added antioxidant standards were recoverable within 98–99% from oils and over 93% from mouse blood. This method requires minimum sample extraction and purification before analysis and provides a relatively high percentage recovery. The method has been applied successfully for the measurement of antioxidant concentrations in oils, dried foods, and biological fluids.
6q deletion in Waldenström macroglobulinemia is associated with features of adverse prognosis
Authors: Ocio E. M. , Schop R. F. J. , Gonzalez B. , Van Wier S. A. , Hernandez‐Rivas J. M. , Gutierrez N. C. , Garcia‐Sanz R. , Moro M. J. , Aguilera C. , Hernandez J. , Xu R. , Greipp P. R. , Dispenzieri A. , Jalal S. M. , Lacy M. Q. , Gonzalez‐Paz N. , Gertz M. A. , San Miguel J. F. , Fonseca R. 
Published: November 2006

SummaryFluorescence in situ hybridisation (FISH) is an effective technique for the cytogenetic analysis of Waldenström macroglobulinemia (WM), but the potential impact of molecular cytogenetics on disease evolution and as a prognostic marker is still unknown. Deletion of the long arm of chromosome 6 (6q−) is the most frequent cytogenetic abnormality in WM. This study analysed the prevalence of this aberration in 102 WM patients, and correlated it with disease characteristics. The incidence of 6q21 deletion was 7% by conventional cytogenetics and 34% when analysed by FISH (54% when cytoplasmic immunoglobulin M‐FISH was used). Patients with deletion of 6q displayed features of adverse prognosis, such as higher levels of β2‐microglobulin and monoclonal paraprotein and a greater tendency to display anaemia and hypoalbuminemia. Interestingly, there was a correlation between the presence of 6q deletion and the International Staging System prognostic index (incidence of 6q− among patients stratified in stages 1, 2 and 3 was 24%, 42% and 67% respectively). Those patients diagnosed with smouldering WM who displayed the abnormality showed a trend to an earlier requirement of treatment. Finally, the survival analysis did not show differences between the two groups of patients, probably due to the short follow up of our series.
Possibility of selection of chondrogenic progenitor cells by telomere length in FGF‐2‐expanded mesenchymal stromal cells
Authors: Yanada S. , Ochi M. , Kojima K. , Sharman P. , Yasunaga Y. , Hiyama E. 
Published: November 2006

Abstract.  Telomere length plays an important role in regulating the proliferative capacity of cells, and serves as a marker for cell cycle history and also for their remaining replicative potential. Mesenchymal stromal cells (MSC) are known to be a significant cell source for therapeutic intervention and tissue engineering. To investigate any possible limitations in the replicative potential and chondrogenic differentiation potential of fibroblast growth factor‐2‐expanded MSCs (FGF(+)MSC), these cells were differentiated at various population doublings (PDs), and telomere length and telomerase activity were measured before and after differentiation. FGF(+)MSC cultured at a relatively low density maintained proliferation capability past more than 80 PD and maintained chondrogenic differentiation potential up to at least 46 PD and long telomeres up to 105 PD, despite expressing low levels of telomerase activity. Interestingly, upon chondrogenic differentiation of these cells, telomeres showed a remarkable reduction in length. This shortening was more extensive when FGF(+)MSC of higher PD levels were differentiated. These findings suggest that telomere length may be a useful genetic marker for chondrogenic progenitor cells.
Assessment of pluripotency and multilineage differentiation potential of NTERA‐2 cells as a model for studying human embryonic stem cells
Authors: Pal Rajarshi , Ravindran Geeta 
Published: November 2006

Abstract.  Embryonal carcinoma cells are pluripotent stem cells derived from teratocarcinomas and are considered to be the malignant counterparts of human embryonic stem cells. As there are few reliable experimental systems available to study the molecular mechanisms governing normal embryogenesis, well‐characterized human embryonal carcinoma stem cell lines may provide a robust and simple model to study certain aspects of pluripotency and cellular differentiation. Here, we have analysed NTERA‐2 cL.D1 cells at molecular and cellular levels during expansion and differentiation, via formation of cell aggregates similar to embryoid bodies in embryonic stem cells. Thus, human embryonal carcinoma cells may provide a valuable insight into cell fate determination, into the embryonic ectoderm, mesoderm and endoderm and their downstream derivatives.
Targeting adenosine receptors in the treatment of allergic rhinitis: a randomized, double‐blind, placebo‐controlled study
Authors: Rimmer J. , Peake H. L. , Santos C. M.C. , Lean M. , Bardin P. , Robson R. , Haumann B. , Loehrer F. , Handel M. L. 
Published: November 2006

SummaryBackground
There is evidence that adenosine plays a role in the pathogenesis of asthma and rhinitis; however, it is currently unclear whether adenosine receptors are useful therapeutic targets in the treatment of allergic airway diseases.Objective
The study evaluated the efficacy of intranasal treatment with an adenosine A2A receptor agonist/adenosine A3 receptor antagonist (50 μg), administered twice daily for 7 days, to reduce nasal symptoms and release of inflammatory mediators following intranasal allergen challenge in patients with allergic rhinitis (AR). The compound was compared with twice‐daily treatment with intranasal fluticasone proprionate nasal spray (FPANS) for 7 days.Methods
A randomized, double‐blind, double‐dummy, placebo‐controlled, three‐way balanced, incomplete block, crossover study was conducted on 48 males with verified AR. Following intranasal challenge with either an extract from the house dust mite (HDM), Dermatophagoides pteronyssinus, rye grass or cat dander, nasal responses and the concentrations of albumin, tryptase, myeloperoxidase, eosinophilic cationic protein, epithelial neutrophil‐activating protein‐78 (ENA‐78), IL‐5 and IL‐8 in nasal secretions were measured and treatment groups were compared.Results
Drug improved nasal blockage but had no significant effect on rhinorrhoea, number of sneezes or peak nasal inspiratory flow measurements when compared with placebo. Drug reduced tryptase release after EAR but did not significantly reduce the levels of other mediators.Conclusion
A novel agonist/antagonist of adenosine A2A and A3 receptors appears to have limited clinical benefit in both the early‐phase and the late‐phase response to intranasal allergen challenge. However, reduction of some pro‐inflammatory mediators suggests that comparable, more selective compounds may have additional benefits meriting further investigation.
Effects of elevated O3, alone and in combination with elevated CO2, on tree leaf chemistry and insect herbivore performance: a meta‐analysis
Authors: VALKAMA ELENA , KORICHEVA JULIA , OKSANEN ELINA 
Published: November 2006

AbstractWe reviewed the effects of elevated ozone (O3), alone and in combination with elevated carbon dioxide (CO2) on primary and secondary metabolites of trees and performance of insect herbivores by means of meta‐analysis. Our database consisted of 63 studies conducted on 22 species of trees and published between 1990 and 2005. Ozone alone had no overall effect on concentrations of carbohydrates or nutrients, whereas in combination with CO2, elevated O3 reduced nutrient concentrations and increased carbohydrate concentrations. In contrast to primary metabolites, concentrations of phenolics and terpenes were significantly increased by 16% and 8%, respectively, in response to elevated O3. Effects of ozone in combination with elevated CO2 were weaker than those of ozone alone on phenolics, but stronger than those of ozone alone on terpenes. The magnitude of secondary metabolite responses depended on the type of ozone exposure facility and increased in the following order: indoor growth chamber <open‐top chamber <free‐air ozone exposure. The results of meta‐analysis demonstrated that, in terms of leaf chemistry, angiosperms are more responsive to elevated O3 than gymnosperms, as shifts in concentrations of carbohydrate and phenolics were observed in the former, but not in the latter. Elevated O3 had positive effects on some indices of insect performance: pupal mass increased and larval development time shortened, but these effects were counteracted by elevated CO2. Therefore, despite the observed increase in secondary metabolites, elevated O3 tends to increase tree foliage quality for herbivores, but elevated CO2 may alleviate these effects. Our meta‐analysis clearly demonstrated that effects of elevated O3 alone on leaf chemistry and some indices of insect performance differed from those of O3+CO2, and therefore, it is important to study effects of several factors of global climate change simultaneously.
Durum wheat quality: II. The relationship of kernel physicochemical composition to semolina quality and end product utilisation
Authors: Samaan Jihad , El‐Khayat Ghassan H. , Manthey Frank A. , Fuller Mick P. , Brennan Charles S. 
Published: November 2006

SummaryKernel quality characteristics, semolina milling potential, dough rheology and pasta making properties of kernels from nine fully irrigated Syrian durum wheat genotypes were observed. Protein content of the kernels exerted a significant affect on the physical characteristics hardness and the degree of kernel vitreousness, both of which were highly correlated with superior end‐use product. Gluten composition of semolina appeared as significant as overall protein content in determining the optimum end‐use product cooking quality (cooking time and pasta texture). The final viscosity of durum flour exhibited positive correlations with semolina recovery, protein content, gluten content, vitreousness, the optimum‐cooking time of pasta and pasta firmness. This indicates the relevance of using the rapid visco analyser technique in evaluating the durum wheat and pasta qualities. Dough rheology measurements confirmed that farinograph and extensograph are useful indicators of the cooking properties of pasta. The research also illustrates that although variability between Syrian durum wheat genotypes were observed, their milling and processing parameters were similar to those previously reported for Canadian and American durum wheats, indicating the potential to use these lines in mainstream pasta production.