Effects of exercise-induced stress and dexamethasone on plasma hormone and glucose concentrations and sedation in dogs treated with dexmedetomidine

OBJECTIVE: To compare the effects of pretreatment with dexamethasone, physical stress (exercise), or both on sedation and plasma hormone and glucose concentrations in dogs treated with dexmedetomidine (DEX). ANIMALS: 6 healthy purpose-bred Beagles. PROCEDURE: Dogs received 4 treatments each in a randomized order prior to i.v. administration of DEX (5 fLg/kg). Pretreatments were as follows: (1) i.v. administration of saline (0.9% NaCI) solution and no exercise (control group); (2) IV administration of dexamethasone (0.05 mg/kg) and no exercise (DM group); (3) i.v. administration of saline solution and exercise (EX group; 15 minutes of trotting on a treadmill at a speed of 2 m/s); and (4) i.v. administration of dexamethasone and exercise (DM+EX group). RESULTS: Following DEX administration, all dogs had similar times to recumbency and sedation index values, irrespective of pretreatment with values, irrespective of pretreatment with dexam-d ethasone or exercise. Plasma catecholamine concentrations decreased after DEX administration. Compared with control group dogs, plasma cortisol concentrations were higher in EX-group dogs prior to DEX administration and lower in DM- and DM+EX-group dogs following DEX administration. Administration of DEX decreased plasma cortisol concentration in EX-group dogs only. Plasma glucose concentration was not influenced by exercise or dexamethasone administration was lower than baseline concentrations at 30 minutes after DEX administration and returned to baseline values by 90 minutes. Heart and respiratory rates and rectal temperature increased during exercise. After DEX administration, these values decreased below baseline values. The decrease in heart rate was of shorter duration in dogs that underwent pretreatment with dexamethasone, exercise, or both than in control group dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Pretreatment with dexamethasone, moderate physical stress (exercise), or both did not influence sedation or cause adverse effects in healthy dogs treated with DEX.     

Microbially safe utilization of non-inactivated oats (Avena sativa L.) for production of conjugated linoleic acid

A microbially safe process for the enrichment of conjugated linoleic acid (CLA) in oats was developed. The process consists of hydrolysis of oat lipids by non-inactivated oat flour, followed by propionibacterium-catalyzed isomerization of the resulting free linoleic acid to CLA. The first stage was performed at water activity (a(w)) 0.7, where hydrolysis of triacylglycerols progressed efficiently without growth of the indigenous microflora of flour. Thereafter, the flour was incubated as a 5% (w/v) aqueous, sterilized slurry with Propionibacterium freudenreichii ssp. shermanii. The amount of CLA produced in 20 h was 11.5 mg/g dry matter corresponding to 116 mg/g lipids or 0.57 mg/mL slurry. The oat flour had also the capability to hydrolyze exogenous oils at a(w) 0.7. Sunflower oil, added to increase linoleic acid content in triacylglycerols 2.7-fold, was hydrolyzed rapidly. Isomerization of this oil-supplemented flour as a 5% slurry gave final CLA content of 22.3 mg/g dry matter after 50 h of fermentation, corresponding to 118 mg/g lipids or 1.14 mg/mL slurry. Storage stability of CLA in fermented oat slurries at 4 degrees C was good.     

Impact of water content on the solubilisation of arabinoxylan during xylanase treatment of wheat bran

Arabinoxylan (AX) has a major impact on the functional properties of wheat bran, and it has been shown that technological properties of bran can be improved by using endoxylanases. Enzymatic treatments are typically conducted at high water content. However, in industrial applications, low water content may be advantageous, especially when targeting dry end products. The aim of the study was to examine the impact of water content, ranging from 20 to 90%, on the efficiency of endoxylanase treatment of wheat bran. Interestingly, AX solubilisation was highest at the water contents of 40 and 90%. At water contents 50–80%, AX solubilisation was lower than at 40 and 90%. Furthermore, at low water content, less depolymerisation was detected. At water content of 40%, the bran-water mixture was transformed from powder-like into compact mass. Probably the compact consistency of the material enhanced AX solubilisation by increased breakdown of bran cell walls due to shear forces or via enhanced enzyme binding to the substrate. The results show that solubilisation of bran AX can also be efficiently performed at low water content.     

Odour Monitoring by Combined TD?CGC?CMS?CSniff Technique and Dynamic Olfactometry at the Wastewater Treatment Plant of Low H2S Concentration

Soil, olive leaves, and fruits, were sampled from an olive grove 200 ha, irrigated with treated municipal wastewater (TMWW), located at Al-Tafilah wastewater processing plant (WWPP), Jordan. Similar samples were also taken from plants not irrigated with TMWW (Control). The heavy metal and essential nutrients were determined in all samples, and the data were statistically processed. The following were found: Much smaller quantities of heavy metals than essential elements were accumulated in the leaves and fruits, the accumulation being independent of the TMWW heavy metal concentration, suggesting a selective uptake of the metals by the olive plants. Also the elemental interactions, which occurred in the olive fruits, contributed mainly essential nutrients and secondarily heavy metals. The trend of heavy metal transfer from soil to olive fruits, and leaves, was almost the same, showing a consistency of transfer.     

In vitro cultivation of a newly recognized Babesia sp. in dogs in North Carolina

A novel large Babesia sp. from an infected dog was cultivated in vitro by microaerophilous stationary phase culture methodology. A primary culture initiated in enriched RPMI-1640 medium supplemented with 40% canine serum and incubated in a 2% oxygen environment supported parasite growth in vitro. Subsequent subcultures into enriched HL-1 medium with 20% fetal bovine serum also supported parasite propagation. Cultures were successfully introduced to 5% carbon dioxide in air atmosphere at passage 4. To date, the parasites have been continuously cultured through 35 passages, although the parasitemias are low, ranging from 0.2 to 0.3%. Parasites cultured in RPMI with canine serum were cryopreserved and successfully recovered from liquid nitrogen storage. The small subunit ribosomal rRNA gene sequence was identical in blood-derived and culture-derived parasites, differing in a single base position from the previously reported sequence for this Babesia sp. The ultrastructure of the parasite was consistent with that of other large Babesia spp., except that the spherical body contained numerous round particles unlike the inclusions previously described in Babesia spp.     

Phenotypic and genetic variation in Finnish potato-late blight populations, 1997–2000

This study was conducted on potato late blight samples collected for monitoring early attacks in Finland from 1997 to 2000. Most of the 1726 Phytophthora infestans isolates were collected soon after the onset of the epidemics. Most of the isolates were tested for mating type as well as metalaxyl and propamocarb hydrochloride (HCl) sensitivity, while virulence on potato R-gene differentials and mitochondrial DNA (mtDNA) haplotype were determined for a subset of the isolates. In half of the fields from which more than one isolate was tested, both mating types were detected, indicating strong potential for sexual reproduction. The mating types coexisted more often in organic fields or gardens than in conventional fields. The proportion of A1 mating type decreased from approximately 80% (1997 and 1998) to 22% by the year 2000. Simultaneously, the proportion of isolates resistant to metalaxyl decreased from approximately 40% to 16%. Resistance to metalaxyl was confined to the IIa mtDNA haplotype and clearly associated with the A1 mating type, as resistance was 10 times more common among A1 isolates than among A2 isolates. Resistance to metalaxyl therefore probably derives from common descent from an isolate with the IIa haplotype. Most of the regional variation in metalaxyl sensitivity was also linked to mating type, as both metalaxyl resistance and the A1 mating type were most common in the north and south-west of Finland. In contrast to metalaxyl, only three propamocarb-HCl-insensitive isolates were found, but propamocarb-HCl sensitivity decreased significantly during the study.     

Genotype by environment interaction for length of productive life in Swedish Red and White dairy cattle

In this study the amount of genotype by environment interaction (G×E) for length of productive life of Swedish Red and White dairy cattle was studied. The environmental variables used were the herd-year averages of number of first parity cows, peak yield, protein yield, and productive life. Data were analysed using multi-trait models (using low and high quartile herds) and reaction norm models (using the whole continuous scale). Considerable G×E was found for the trait productive life between environments (herds) with short or long average productive life, and a genetic correlation of 0.74 was found. For productive life in relation to herd size, G×E was negligible, and the genetic correlation was 0.95. For productive life in relation to herd-year average of peak yield or protein yield some G×E was indicated by the reaction norm model, especially between extreme environments. The G×E between herds with short or long average productive life should be studied further and might need to be considered in breeding programmes for dairy cattle.     

Clostridium difficile in faeces from healthy dogs and dogs with diarrhea

Background

This study was conducted to evaluate the faecal occurrence and characterization of Clostridium difficile in clinically healthy dogs (N = 50) and in dogs with diarrhea (N = 20) in the Stockholm-Uppsala region of Sweden.

Findings

Clostridium difficile was isolated from 2/50 healthy dogs and from 2/20 diarrheic dogs. Isolates from healthy dogs were negative for toxin A and B and for the tcdA and tcdB genes. Both isolates from diarrheic dogs were positive for toxin B and for the tcdA and tcdB genes. The C. difficile isolates from healthy dogs had PCR ribotype 009 (SE-type 6) and 010 (SE-type 3) whereas both isolates from dogs with diarrhoea had the toxigenic ribotype 014 (SE-type 21). One of the isolates from healthy dogs was initially resistant to metronidazole.

Conclusions

This study revealed presence of toxigenic C. difficile in faecal samples of diarrheic dogs and low number of non- toxigenic isolates in healthy dogs from Uppsala-Stockholm region in Sweden. However, more comprehensive studies are warranted to investigate the role of C. difficile in gastrointestinal disease in dogs.     

Phenotypic variation in Nordic populations of Phytophthora infestans in 2003

A total of 743 single-lesion isolates of Phytophthora infestans were collected in summer 2003 from Denmark, Finland, Norway and Sweden. Most of the isolates were tested for mating type, and subsets were tested for sensitivity to fungicides and virulence (host specific pathogenicity). Approximately 60% of the isolates were A1 mating type in each country. Both mating types were present in 40% of the fields where more than one isolate was tested, indicating strong potential for sexual reproduction. The proportion of metalaxyl-resistant isolates dropped to under 15% from the 60% observed in the early 1990s in Norway and Finland, possibly due to lower selection pressure because of decreased use of metalaxyl. Propamocarb-HCl sensitivity remained unchanged in the Nordic countries compared to the situation in 1997–2000 in Finland. Four isolates collected from Finland and Sweden were able to sporulate in the presence of this fungicide at a concentration of 1000 mg L⁻¹. In Norway and Finland the frequencies of virulence factors and pathotypes remained nearly unchanged since the 1990s, but the mean number of virulence factors per isolate increased from 5·6 to 6·3. In Denmark and Sweden virulence factors 2 and especially 6 were more common than in Norway and Finland. In addition, in the Swedish population the frequencies of pathotypes were quite even while in other countries pathotype 1,3,4,7,10,11 was most prevalent.     

The elusive role of soil quality in nutrient cycling: a review

Cycling of nutrients, including nitrogen and phosphorus, is one of the ecosystem services we expect agricultural soils to deliver. Nutrient cycling incorporates the reuse of agricultural, industrial and municipal organic residues that, misleadingly, are often referred to as ‘wastes’. The present review disentangles the processes underlying the cycling of nutrients to better understand which soil properties determine the performance of that function. Four processes are identified (i) the capacity to receive nutrients, (ii) the capacity to make and keep nutrients available to crops, (iii) the capacity to support the uptake of nutrients by crops and (iv) the capacity to support their successful removal in harvested crop. Soil properties matter but it is imperative that, as constituents of ‘soil quality’, they should be evaluated in the context of management options and climate and not as ends in their own right. The effect of a soil property may vary depending on the prevailing climatic and hydrologic conditions and on other soil properties. We recognize that individual soil properties may be enhancing one of the processes underlying the cycling of nutrients but simultaneously weakening others. Competing demands on soil properties are even more obvious when considering other soil functions such as primary production, purification and flow regulation of water, climate modification and habitat provision, as shown by examples. Consequently, evaluations of soil properties and management actions need to be site‐specific, taking account of local aspects of their suitability and potential challenges.