Antioxidant activity of knotwood extractives and phenolic compounds of selected tree species

The antioxidant potency and the radical scavenging capacity of superoxide and peroxyl radicals were assessed for 13 hydrophilic knotwood extracts of commercially important wood species, or fractions thereof, as well as for five pure wood-derived lignans and the flavonoid taxifolin. The chemical composition of the knotwood extracts was determined by gas chromatography combined with mass spectrometry. Most of the investigated wood species were rich in hydrophilic extractives (10-20% of the dry wood) with one or a few compounds dominating in each extract. All extracts had a high antioxidative potency and/or radical scavenging capacity as compared to the well-known antioxidants Trolox and butylated hydroxyanisole. The pure wood-derived lignans and taxifolin also had a high antioxidative potency and/or radical scavenging capacity. However, the antioxidant potency and/or radical scavenging capacity of several of the hydrophilic knotwood extracts were higher than that of the dominating compounds in pure form.     

Epidemiology of methicillin resistant Staphylococcus pseudintermedius in guide dogs in Finland

Background

Methicillin resistant Staphylococcus pseudintermedius (MRSP) and Staphylococcus aureus (MRSA) are common multi-drug resistant (MDR) bacteria in dogs. In 2012–2013 three dogs of the Guide Dog School of the Finnish Federation of the Visually Impaired were found to be MRSP positive. Guide dogs have regular contact with each other during their first year of life and prolonged contact when in training. Since dogs are placed in different parts of Finland after training, there is a risk for national spread of MDR bacteria. In this study the prevalence of MRSP and MRSA, as well as the risk factors for MRSP were determined in the Finnish guide dog population. MRSP isolates were investigated using molecular methods and compared to the earlier isolates.

Results

Out of 132 tested dogs 4 were MRSP positive thus giving the prevalence estimate of 3% (95% CI: 1–8%) for MRSP in the target population. MRSA was not detected (prevalence estimate 0%, 95% CI: 0–3%). Risk factors associated with MRSP were being a breeding bitch (OR = 8.4; 95% CI: 1.1–64.1, P = 0.012), the number of veterinary visits (OR = 1.23; 95% CI: 1.0–1.5, P = 0.025) and number of antimicrobial courses (OR = 1.63; 95% CI: 1.0–2.55; P = 0.035). Identified MRSP isolates belonged to five different sequence types (ST45, 71, 402, 403 and 404). All ST71 isolates carried SCCmec II-III, while the SCCmec type of the ST45 and ST402 (a single locus variant of ST45) isolates were non-typeable with the method used.

Conclusions

MRSP and MRSA had low prevalence in the studied dog population despite the close contact between dogs, and the MRSP population was heterogenic. Antimicrobial therapy and veterinary visits are risk factors for MRSP even among a small case group.

Electronic supplementary material

The online version of this article (doi:10.1186/s13028-015-0129-8) contains supplementary material, which is available to authorized users.     

Solution properties of single-walled carbon nanotubes

Naked metallic and semiconducting single-walled carbon nanotubes (SWNTs) were dissolved in organic solutions by derivatization with thionychloride and octadecylamine. Both ionic (charge transfer) and covalent solution-phase chemistry with concomitant modulation of the SWNT band structure were demonstrated. Solution-phase near-infrared spectroscopy was used to study the effects of chemical modifications on the band gaps of the SWNTs. Reaction of soluble SWNTs with dichlorocarbene led to functionalization of the nanotube walls.     

Redox signaling in chloroplasts: cleavage of disulfides by an iron-sulfur cluster

Light generates reducing equivalents in chloroplasts that are used not only for carbon reduction, but also for the regulation of the activity of chloroplast enzymes by reduction of regulatory disulfides via the ferredoxin:thioredoxin reductase (FTR) system. FTR, the key electron/thiol transducer enzyme in this pathway, is unique in that it can reduce disulfides by an iron-sulfur cluster, a property that is explained by the tight contact of its active-site disulfide and the iron-sulfur center. The thin, flat FTR molecule makes the two-electron reduction possible by forming on one side a mixed disulfide with thioredoxin and by providing on the opposite side access to ferredoxin for delivering electrons.     

Elevated concentrations of CSF corticotropin-releasing factor-like immunoreactivity in depressed patients

The possibility that hypersecretion of corticotropin-releasing factor (CRF) contributes to the hyperactivity of the hypothalamo-pituitary-adrenal axis observed in patients with major depression was investigated by measuring the concentration of this peptide in cerebrospinal fluid of normal healthy volunteers and in drug-free patients with DSM-III diagnoses of major depression, schizophrenia, or dementia. When compared to the controls and the other diagnostic groups, the patients with major depression showed significantly increased cerebrospinal fluid concentrations of CRF-like immunoreactivity; in 11 of the 23 depressed patients this immunoreactivity was greater than the highest value in the normal controls. These findings are concordant with the hypothesis that CRF hypersecretion is, at least in part, responsible for the hyperactivity of the hypothalamo-pituitary-adrenal axis characteristic of major depression.     

Interspecies conversion of Clostridium botulinum type C to Clostridium novyi type A by bacteriophage

When Clostridium botulinum type C is cured of its prophage it simultaneously ceases to produce toxin. This nontoxigenic culture can then be converted to another toxigenic bacterial species, Clostridium novyi type A or to toxigenic Clostridium botulinum types C or D, by specific bacteriophages. The toxigenicity and type of toxin produced by these cultures depends upon the continued presence of these bacteriophages.     

Some chemical and biological properties of a protein concentrate from nigerseed (Guizotia abyssinica Cass.)

A protein concentrate has been prepared from nigerseed (Guizotia abyssinica Cass.) by a method involving extraction of the protein with NaCl-solution.The protein concentrate contains about 65% of protein (N×5.5) calculated from the dry weight, and the amino acid pattern is fairly well balanced. The chemical score is 82 calculated from the A/E values.The nutritional value of the product has been tested on young rats. These tests revealed the presence of antinutritional factors in the protein concentrate. The PER was only 1.5.It was also found that the rate of digestion by pancreatin was much slower for the protein concentrate than for casein, possibly due to enzyme resistent linkages.The protein concentrate seems to be devoid of hemagglutinin activity. Antibodies against the nug extracts could not be found.

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Zusammenfassung Ein Proteinkonzentrat wurde aus Nug-Samen (Guizotia abyssinica Cass.) durch eine Methode gewonnen, die eine Extraktion des Proteins mit NaCl-Lösung einschließt.Das Proteinkonzentrat enthalt etwa 65% Protein (N x 5,5), berechnet auf das Trockengewicht. Das Aminosäuregleichgewicht ist relativ gut balanziert. Die chemical score nach den A/E Werten berechnet, beträgt 82.Der Nährwert des Produktes ist an jungen Ratten getestet worden. Diese Tests zeigten das Vorhandensein von Antinähr-Faktoren im Proteinkonzentrat. Die PER (protein efficiency ratio) betrug nur 1,5.Es wurde außerdem festgestellt, daß die Geschwindigkeit der enzymatischen Verdauung (mit Pankreatin) für das Proteinkonzentrat viel langsamer abläuft als für Casein. Dieses ist vielleicht bedingt durch Enzymresistente Bindungen.Das Proteinkonzentrat scheint von Hämagglutininaktivität frei zu sein. Es wurden keine Antikörper gegen Nug-Extrakte gefunden.

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Résumé Une solution concentrée de protéine a été préparée de grains de nug (Guizotia abyssinica Cass.) par une méthode contenant l'extraction de la protéine avec la solution NaCl.La solution concentrée contient environ 65% de protéine (N X 5,5) calculée du poids sec, et le modèle des aminoacides est assez bien balancé. Le chemical score est 82 calculé des valeurs A/E. La valeur nutritive du produit a été éprouvé à de jeunes rats. Ces épreuves ont révélé la présence d'éléments antinutritives dans la solution concentrée de protéine. La PER (protein efficiency ratio) était seulement 1,5.On a aussi trouvé que la rapidité de digestion enzymatique (avec la pancréatine) pour la solution concentrée de protéine était beaucoup plus lente que pour le casein. Ceci est peut-être du à des liaisons qui résistent aux enzymes.Il semble que la solution concentrée de protéine manque d'activité hemagglutinine. On n'a pas pu trouver des anticorps dirigés contre les extraits de nug.

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CNU Report No. 34.     

Fresh Water: Temperature of Maximum Density Calculated from Compressibility

Measurement of sonic velocities in water provides an accurate method for determining the equation of state for water. A simple equation of state for fresh water yields the temperature of maximum density as a function of pressure.     

Bioavailability of cadmium from in vitro digested infant food studied in Caco-2 cells

The solubility and bioavailability of cadmium (Cd) in infant foods, three cereal- and milk-based diets and two ready-to-use baby dishes, were studied after in vitro digestion and by using human intestinal Caco-2 cells. The solubility of Cd after in vitro digestion varied between diets; liver casserole had the highest solubility and was lower after infant as compared to adult digestion conditions. Generally, more Cd was soluble in infant intestinal than gastric juice in contrast to the results from the adult digestion. Caco-2 cells were incubated with supernatants of infant digests that had been equilibrated with (109)Cd during the in vitro digestion procedure, and cellular uptake and transport of (109)Cd were measured after 180 min. Statistically significant differences in both uptake and transport of Cd were detected between some of the diets and a control solution containing only digestive enzymes and (109)CdCl(2). Uptake of soluble Cd in the cells varied between diets from 4 to 6%, and the transport over the monolayers was 1-2% of the dose. We conclude that age specific digestion conditions as well as composition of diets affect both solubility and bioavailability of Cd.     

Standardized ileal digestibility of amino acids in European soya bean and rapeseed products fed to growing pigs

This study was conducted to determine the chemical composition and standardized ileal digestibility coefficients (SID) of crude protein (CP) and amino acids (AA) of European soya bean and rapeseed products in pigs. Six soya bean and two rapeseed products were used as the sole dietary source of CP and AA, including raw (FFSB) and roasted full‐fat soya beans (FFSB_Roasted), soya bean (SBC) and rapeseed cake (RSC), and rapeseed meal (RSM) from Bavaria (Germany), soya bean meal (SBM) from the Danube region (Austria; SBM_Austria), a commercially available standard SBM (SBM_Std) and an imported genetically modified organism‐free SBM (SBM_GMO‐free). Eight ileal‐ cannulated pigs with an initial body weight of 32 ± 2 kg were allotted to a row‐column design with eight diets and six periods of seven days each. Trypsin inhibitor activity (TIA) ranged from 1.8 in SBM_Std to 24.5 mg/g DM in FFSB. The SID of CP and all AA in FFSB_Roasted were greater than in FFSB, but lower when compared to SBC and SBM_Austria (p < .05). The SID of CP and all AA (except glutamic acid) were not different between SBC and SBM_Austria, but the SID of CP and all AA (except methionine) were greater (p < .05) in SBC than in SBM_GMO‐free. Furthermore, the SID of CP and most AA showed a quadratic response with decreasing TIA, and there exists a quadratic response in SID of CP and all AA with increasing lysine to CP ratio and neutral detergent insoluble nitrogen (p < .05). In conclusion, variation in chemical composition and SID of CP and AA was observed in different European soya bean and rapeseed products as influenced by differences in processing conditions. European SBC and SBM_Austria can be used as alternative to imported SBM_GMO‐free and SBM_Std in diets for growing pigs.