Dietary carbohydrate modification alters serum metabolic profiles in individuals with the metabolic syndrome.

BACKGROUND AND AIMS: Whole-grain cereals and diets with a low glycemic index may protect against the development of type 2 diabetes and heart disease, but the mechanisms are poorly understood. We studied the effect of carbohydrate modification on serum metabolic profiles, including lipids and branched chain amino acids, and dependencies between these and specific gene expression pathways in adipose tissue. METHODS AND RESULTS: Twenty subjects with metabolic syndrome were selected from the larger FUNGENUT study population, randomized either to a diet high in oat and wheat bread and potato (OWP) or rye bread and pasta (RP). Serum metabolomics analyses were performed using ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry (UPLC/MS), gas chromatography (GC) and UPLC. In the OWP group multiple proinflammatory lysophosphatidylcholines increased, while in the RP group docosahexaenoic acid (DHA 22:6n-3) increased and isoleucine decreased. mRNA expression of stress reactions- and adipose tissue differentiation-related genes were up-regulated in adipose tissue in the OWP group. In the RP group, however, pathways related to stress reactions and insulin signaling and energy metabolism were down-regulated. The lipid profiles had the strongest association with the changes in the adipose tissue differentiation pathway when using the elastic net regression model of the lipidomic profiles on selected pathways. CONCLUSION: Our results suggest that the dietary carbohydrate modification alters the serum metabolic profile, especially in lysoPC species, and may, thus, contribute to proinflammatory processes which in turn promote adverse changes in insulin and glucose metabolism.

Efficient enantioselective separation of drug enantiomers by immobilised antibody fragments.

There is an increasing need for methods for efficient enantioselective separation and purification of chiral drugs. Genetic engineering provides the means for generating recombinant antibodies exhibiting extremely high specificity for even small molecular mass compounds. Here, recombinant antibody fragments have been generated for the drug diarylalkyltriazole that contains two chiral centres. Immobilised antibody fragments has been used successfully for efficient, step-wise separation of two enantiomers of the drug. Owing to the antibody specificity, one enantiomer came out in the flow-through, while the bound enantiomer could be specifically eluted. One of the antibodies tolerated solvents required both for dissolving the target molecules and for their elution for extended times and was shown to function over multiple cycles of the separation process.

Ropy slime formation in vacuum-packed cooked meat products caused by homofermentative lactobacilli and a Leuconostoc species.

This paper deals with the cause of the formation of ropy slime on the surface of vacuum-packed cooked meat products. Two different homofermentative lactobacilli and a Leuconostoc strain were isolated from different ropy vacuum-packed meat products. The strains were able to produce slime experimentally on vacuum-packed cooked sausages. The slime had a molecular weight in the range of 70000-30000 and contained glucose and galactose in a ratio 10:1-10:2. The formation of ropy slime also occurred on sausages without added sugars.

Preliminary characterization of the mutagenic properties of 'necatorin', a strongly mutagenic compound of the mushroom Lactarius necator.

The mutagenic activity of 'necatorin', a strongly mutagenic compound isolated from the wild edible mushroom Lactarius necator, was studied with the Ames test, the bacterial intraperitoneal host-mediated assay and the micronucleus test. Whereas the results of the Ames tests were clearly positive, no evidence of mutagenicity was detectable in host-mediated assays or micronucleus tests.

Stability of necatorin, a highly mutagenic compound from Lactarius necator mushroom.

The mutagenic compound necatorin [7-hydroxycoumaro(5,6-c)cinnoline] was present in fresh Lactarius necator mushrooms at concentrations ranging from 3 to 20 mg/kg. Blanching decreased the concentration of necatorin in the mushrooms to about 25% of the original value. Pure necatorin was shown to be susceptible to decomposition by light, especially at high pH. The destruction of pure necatorin by boiling was most effective at pH 5.0, whereas at the other pH values studied (0.5 and 13.5) necatorin was relatively stable during boiling.

Determination of phenol in poly(vinyl chloride).

There are strong indications that some poly(vinyl chloride) (PVC) plastics may contain phenol. This would be particularly harmful in the case of PVC used as a raw material for toys. An analytical method for determining phenol in PVC was therefore designed. The method is based on dissolving the whole sample in tetrahydrofuran and precipitating PVC by addition of water. After filtration the solution is ready for injection into an HPLC instrument. For quantitative analysis p-cresol is used as internal standard and it is added to the THF solution before precipitation. The method is applicable in the concentration range 50-3000 mg phenol/kg PVC. The detection limit is about 10 mg phenol/kg PVC but may be easily increased ten-fold by gentle removal of tetrahydrofuran from the sample solution and cleaning of the sample with C18 cartridge, which allows the injection of larger volumes and thus improves sensitivity. The method has been submitted for collaborative study in municipal laboratories in Finland.

Size-exclusion chromatographic determination of beta-glucan with postcolumn reaction detection.

Using the specific interaction of beta-glucan with calcofluor dye as a detection method for size-exclusion chromatographic analysis, very simple direct extractions can be used for sample preparation. Either fluorescence or UV detection is employed. The calibration graphs are linear between 200 and 20 mg/l, although much more sensitive analyses are possible. The response remained independent of relative molecular mass in the range studied (1.7 x 10(6)-1.85 x 10(5)). Results for barley and malt show good correlation with those obtained by flow-injection analysis using calcofluor.

Intestinal degradation of dietary fibre in green beans--effects of microwave treatments.

Intestinal degradation of dietary fibre in blanched and microwaved green beans was studied by using a rat experimental model. Content and composition of dietary fibre as well as molecular weight distribution of water-soluble polysaccharides (WSP) were analysed. There was a solubilization and a shift towards lower Mw of mainly uronic acid-containing polysaccharides with repeated microwave treatment in the raw material. Thus, the apparent Mw of water-soluble polysaccharides decreased from approximately 1,550,000 to approximately 300,000. After the beans had been digested the Mw of the WSP was significantly reduced, to approximately 100,000, and the differences in Mw seen between various processed raw materials had been evened out. After fermentation the Mw of the WSP decreased further approximately 10 times. Fibre fermentability was high (approximately 90%) and similar for the various processed beans.

Separation of cyclosporins by high-performance liquid chromatography and mass spectrometric study of cyclosporin metabolites.

A semi-preparative (high-performance liquid chromatography) method for separation of cyclosporin metabolites in a fungal fermentation sample was developed. By using the optimized chromatographic separation, 20 cyclosporin metabolites in a process sample were isolated, and their molecular masses measured by double focusing sector mass spectrometry. The structures of some of the cyclosporin congeners were investigated by tandem sector mass spectrometry using fast atom bombardment ionization. The isobaric cyclosporins D ([Val2] CS) and G ([Nva2] CS) were differentiated by significantly different relative intensities of a fragment ion at m/z 30 [CH4N]+ from a precursor ion at m/z 72 [C4H10N]+. Otherwise the tandem mass spectrometry (MS/MS) spectra of the fragment ions of the two isomers are very similar. Cyclosporin A and iso-cyclosporin A were also analysed by high energy MS/MS. No significant fragment ions were found to provide distinctions between them. Relatively good overviews of process samples containing very similar structures were achieved by combining LC separation, molecular ion recognition and MS/MS characterization.