Characterization of Dog Glutathione Transferase P1-1, an Enzyme Relevant to Veterinary Medicine

Glutathione transferases (GSTs) form a family of detoxication enzymes instrumental in the inactivation and elimination of electrophilic mutagenic and carcinogenic compounds. The Pi class GST P1-1 is present in most tissues and is commonly overexpressed in neoplastic cells. GST P1-1 in the dog, Canis lupus familiaris, has merits as a marker for tumors and as a target for enzyme-activated prodrugs. We produced the canine enzyme CluGST P1-1 by heterologous bacterial expression and verified its cross-reactivity with antihuman-GST P1-1 antibodies. The catalytic activity with alternative substrates of biological significance was determined, and the most active substrate found was benzyl isothiocyanate. Among established GST inhibitors, Cibacron Blue showed positive cooperativity with an IC₅₀ value of 43 nM. Dog GST P1-1 catalyzes activation of the prodrug Telcyta, but the activity is significantly lower than that of the human homolog.     

A trout (Oncorhynchus mykiss) perfusion model approach to elucidate the role of blood removal for lipid oxidation and colour changes in ice-stored fish muscle

Whole body saline-perfused rainbow trout (Oncorhynchus mykiss) was ice-stored for 4 weeks and compared with unwashed/washed minces from unbled and bled trout in terms of rancid odour, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and redness loss. Muscle from saline-perfused fish, which had 72% less total haem, was deficient in rancid odour during the whole storage, while bled (54% less haem) and unbled samples developed rancid odour already after ~4 and 2 days; higher intensity without bleeding. PV/TBARS also developed in the order unbled > bled > perfused samples; however, PV/TBARS were not as completely prevented as rancid odour after perfusion. Saline washing (3 × 3 volumes) of unbled mince removed 84% haem and yielded the second most stable sample while saline washing (1 × 1 volumes) destabilised unbled mince, despite 64% haem removal. Concurrent antioxidant removal during washing of minces obviously counteracted the effect of blood removal and washing fish mince with small volumes of solution should be used with great care.     

ErgoVSM: A Tool for Integrating Value Stream Mapping and Ergonomics in Manufacturing

Value stream mapping (VSM) is a lean tool aiming at waste reduction. Previous research suggests that the use of VSM may result in work intensification and thus an increased risk for the workers of developing work‐related musculoskeletal disorders (MSD). In the current study, VSM was developed to also consider physical exposure in the analyzed production system (ErgoVSM). As the VSM, ErgoVSM is based on a participatory approach. ErgoVSM was tested in a Swedish manufacturing company. The results suggest that ErgoVSM catalyzes change processes to include intervention proposals emphasizing ergonomics in addition to waste reduction. Thus, ErgoVSM appeared useful for the investigated target group of production engineers and experienced operators. The performance improvements suggested when using the ordinary VSM seemed not to be hampered by adding the ergonomics complement. However, the use of ErgoVSM was somewhat more time consuming than the use of VSM. In conclusion, ErgoVSM is suggested as a feasible tool to be used by production engineers and experienced operators for including ergonomics considerations in the rationalization process.     

Freie und gebundene Sterine in Pflanzenfetten

Free and Bound Sterols in Vegetable Fats Investigations of 15 different vegetable fats have shown that lipoproteins, detected in raw palm oil, occur in other fats, too. The cholesterol content in the sterols of lipoproteins is not always the same; but it is in any case higher than in other sterol containing fractions of these fats. The investigation of the free sterols, sterol esters, sterol glycosides and sterol containing lipoproteins in these 15 fats shows that cholesterol occurs more or less in all vegetable fats, but in an analytically difficult accessible way.     

Relaxed step functions for evaluation of CCN counter data on size-separated aerosol particles

Atmospherically important data are gained from cloud condensation nucleus counter (CCNC) analysis of aerosols that are particle mobility separated using differential mobility analysers (DMA). We present relaxed step functions that can be fitted to these data to obtain critical diameters or critical supersaturations. The step functions are based on the DMA transfer function. We treat the case with fixed supersaturation and varied particle diameter as well as fixed particle size and varied supersaturation. Comparison with experimental data shows that the width of the DMA transfer function controls the steepness of the relaxed step function. The less steep slope in the activation curve caused by the presence of a slightly soluble compound in the particle is discussed. Also in this case, the DMA transfer function width influences the steepness of the activation curve. Finally we demonstrate the errors made if doubly charged particles are not accounted for and a wide DMA transfer function is used.     

The influence of complexing agents on the solubility and absorption of aluminium in rats exposed to aluminium in water

The influence of citrate (0-31mm), fluoride (0 or 2.6mM) and silicate (0 or 2.6mM) on the absorption of Al (0-18mM) was studied in rats. We tested the hypothesis that the solubility and absorption of Al increases in the gastrointestinal (GI) tract in the presence of the complexing agents. Male rats were exposed for 6 or 7 weeks to soluble Al in acidic drinking water (pH 2.5-3.0) with or without the complexing agents. At the end of exposure Al was fractionated in the stomach content, in order to study if the solubility of Al was changed after ingestion. Al absorption was estimated by Al analysis of the right femur bone. Speciation calculations indicated that citrate and fluoride caused formation of soluble Al-citrate (97%) and -fluoride (>60%) complexes in the water. Silicate did not affect the theoretical speciation. In all cases, a large fraction of soluble Al became insoluble in the stomach after ingestion. The concentration of soluble Al increased only in the presence of citrate or a mixture of fluoride and silicate, but citrate was the only complexing agent that influenced the absorption of Al in the rat. This indicates that the form of Al may be changed in the GI tract when soluble drinking-water Al is ingested, and that the solubility of Al in drinking water and GI tract may not be good predictors of the bioavailability of Al even when chelating agents are present.     

An HPLC Method for Analysis of HNIW and TNAZ in an explosive mixture

This paper presents a general HPLC method for qualitative and quantitative analysis of mixtures of explosives. The method has successfully been tested on the following explosives: RDX, 2,4,6-TNT, 2,4-DNT, HMX, PETN, Tetryl, HNS, TNAZ and HNIW. The method permits a nine component explosive mixture analysis in less than 10 minutes. For HNIW and TNAZ the detection limit was less than 5 ng.     

Local Superfluidity in 4He and para-H2 Clusters

No Heading We present a new definition of local superfluidity around impurities in quantum fluids that provides a consistent analysis of the response of the inhomogeneous fluid density to the impurity rotations. This definition is based on the local decomposition of the moments of inertia of the fluid, which can be estimated from the projected area of exchange-coupled Feynman paths in path integral Monte Carlo calculations. Application to helium droplets doped with a planar phthalocyanine molecule shows that the first solvation layers parallel to the molecular plane consist of localized helium atoms that are totally inert to superfluid response, while the second solvation layers and capping regions at the end of the molecule exhibit partial and anisotropic superfluidity. Application to weakly bound complexes of the linear OCS molecule with para-hydrogen molecules shows evidence for the existence of molecular supersolids. We find that five H₂ molecules constitute a single ring around OCS which possesses both a solid-like pair correlation function and a complete superfluid response to rotation around the molecular axis below T ~ 1 K.PACS numbers: 36.40.–c, 36.40.Mr, 67.40.–w. 67.40. Yv