Pines beyond the polar circle: Adaptation to stress conditions

Summary Plant populations in extreme conditions differ from those in more favorable conditions in many respects. They have developed special physiological adaptations for withstanding e.g. extreme temperatures or drought. On the other hand, low survival and fertility may cause smaller effective population sizes, which in turn influences patterns of genetic variation. Scots pine has the widest range of all pine species, extending in the north far beyond the arctic circle. Close to the tree limit, the growing season is short and survival is low. Very northern populations also have lower and more irregular male and female flowering and seed production than southern ones. The consequences of these conditions on genetic variation have been examined. All Finnish populations have similar patterns of variation at allozyme loci and nuclear DNA markers: high variation but no differentiation between populations. Northern populations seem to have slightly fewer recessive deleterious alleles than southern ones. There is, however, strong differentiation between populations with respect to adaptation to the very short growing season. In common garden experiments, northern populations cease growth and set buds much earlier and develop frost tolerance earlier than southern populations. The genetic basis for this high differentiation in bud set can be explored by using dense maps of molecular markers. The implications of these patterns of variations on conservation of genetic resources and tree breeding will be discussed.     

Clinical effects and pharmacokinetics of medetomidine and its enantiomers in dogs

The clinical effects and pharmacokinetics of medetomidine (MED) and its enanti-omers, dexmedetomidine (DEX) and levomedetomidine (LEVO) were compared in a group of six beagle dogs. The dogs received intravenously (i.v.) a bolus of MED (40 microg/kg), DEX (20 and 10 microg/kg), LEVO (20 and 10 microg/kg), and saline placebo in a blinded, randomized block study in six separate sessions. Sedation and analgesia were scored subjectively, and the dogs were monitored for heart rate, ECG lead II, direct blood pressure, respiratory rate, arterial blood gases, and rectal body temperature. Blood samples for drug analysis were taken. Peak sedative and analgesic effects were observed at mean (+/- SD) plasma levels of 18.5 +/- 4.7 ng/mL for MED40, 14.0 +/- 4.5 ng/mL for DEX20, and 5.5 +/- 1.3 ng/mL for DEX10. The overall level of sedation and cardiorespiratory effects did not differ between MED40, DEX20 and DEX10 during the first hour, apparently due to a ceiling effect. However, the analgesic effect of DEX20 lasted longer than the effect of the corresponding dose of racemic medetomidine, suggesting greater potency for dexmedetomidine in dogs. Levomedetomidine had no effect on cardio-vascular parameters and caused no apparent sedation or analgesia. The pharmacokinetics of dexmedetomidine and racemic medetomidine were similar, but clearance of levomedetomidine was more rapid (4.07 +/- 0.69 L/h/kg for LEVO20 and 3.52 +/- 1.03 for LEVO10) than of the other drugs (1.26 +/- 0.44 L/h/kg for MED40, 1.24 +/- 0.48 for DEX20, and 0.97 +/- 0.33 for DEX10).     

Effects of ovariohysterectomy on canine blood neutrophil respiratory burst: a chemiluminescence study

OBJECTIVE: To examine blood neutrophil counts and luminol-enhanced chemiluminescence (CL) responses in dogs undergoing ovariohysterectomy (OH), premedicated with 2 different drugs. STUDY DESIGN: Randomized clinical study. ANIMALS: Forty-two healthy client-owned bitches. METHODS: Dogs had OH under isoflurane anesthesia with either acepromazine or medetomidine, both in combination with butorphanol, administered as preanesthetic medication. Blood samples were collected when the dog was admitted, at the end of surgery, and the next day (approximately 20 hours after surgery). Blood neutrophils were counted automatically, and neutrophil oxidative activity was assessed by measuring blood CL responses (induced by opsonized zymosan and enhanced by luminol) at 37 degrees C for 40 minutes. RESULTS: Number of circulating neutrophils was significantly increased the day after surgery reflected by enhanced blood CL responses. Neutrophil CL, however, was not significantly altered. No significant differences were detected for perioperative Polymorphonuclear neutrophil (PMN) characteristics between the 2 preanesthetic regimens. CONCLUSIONS: In conclusion, despite clearly increasing the number of circulating neutrophils, OH did not significantly affect neutrophil respiratory burst, as measured by whole-blood CL responses. CLINICAL RELEVANCE: Surgical operation of moderate intensity (e.g., OH) did not significantly alter one of the important immune functions, neutrophil oxidative activity. Further studies are warranted to confirm the significance of this finding, and to assess the value of following this variable in different animal patient populations.     

Enzymatic modification and particle size reduction of wheat bran improves the mechanical properties and structure of bran-enriched expanded extrudates

The aim of this study was to examine enzymatic modification of wheat bran, performed in a low-moisture process, and the reduction of bran particle size as means of improving the technological performance of wheat bran in expanded extrudates. Modification of bran by hydrolytic enzymes increased the crispiness and decreased the hardness and piece density of extrudates containing wheat bran and endosperm rye flour in 20:80 ratio. These improvements correlated (P < 0.01 or 0.05) with an increased content of water extractable arabinoxylan and decreased water holding capacity of the bran, as well as with increased longitudinal expansion of the extrudates. Furthermore, bran with a fine average particle size (84 μm) produced extrudates with improved mechanical properties and higher radial expansion than coarse bran (particle size 702 μm). The impact of bran particle size was also observed in the cellular structure of the extrudates as differences in cell size and homogeneity. The bran drying method, oven or freeze drying after enzymatic modification, did not have a major impact on the properties of the extrudates. The study showed that the functionality of wheat bran in extrusion can be improved by enzymatic modification using a low-water process and by reduction of bran particle size.     

The effect of contrast-enhanced ultrasound on the kidneys in eight cats

Contrast-enhanced ultrasound (CEUS) of the left kidney was performed on eight non-anesthetized, young, purpose bred, domestic shorthaired cats. Each cat underwent a physical examination before and 4h and 48h after CEUS. Complete blood count (CBC), serum biochemical analysis, urinalysis, including evaluation of the enzymatic activities of urinary N-acetyl-β-d-glucosaminidase (NAG) and gamma-glutamyl transferase (GGT), were also performed. No changes were observed in CBC or serum biochemical analyses, with the exception of a decrease in blood urea concentration at 48h post-contrast ultrasound. A small elevation in NAG (U/g creatinine) was observed with a mean (SD) increase from 0.53 (0.35) to 1.43 (0.59) U/g creatinine. The magnitude of the rise was less than the circadian variation reported earlier for healthy cats. These results suggest that CEUS can be safely used to assess kidney perfusion in cats. The changes observed in laboratory values after CEUS did not appear to be related to detrimental effects on the kidneys.     

Sublingual administration of detomidine to calves prior to disbudding: a comparison with the intravenous route

ObjectiveTo study the effects of oromucosal detomidine gel administered sublingually to calves prior to disbudding, and to compare its efficacy with intravenously (IV) administered detomidine.Study designRandomised, prospective clinical study.AnimalsTwenty dairy calves aged 12.4 ± 4.4days (mean ± SD), weight 50.5 ± 9.0 kg.MethodsDetomidine at 80 μg kg^?1 was administered to ten calves sublingually (GEL) and at 30 μg kg^?1 to ten control calves IV (V. jugularis). Meloxicam (0.5 mg kg^?1) and local anaesthetic (lidocaine 3 mg kg^?1) were administered before heat cauterization of horn buds. Heart rate (HR), body temperature and clinical sedation were monitored over 240 minutes. Blood was collected from the V. cephalica during the same period for drug concentration analysis. Pharmacokinetic variables were calculated from the plasma detomidine concentration-time data using non-compartmental methods. Statistical analyses compared routes of administration by Student’s t-test and linear mixed models as relevant.ResultsThe maximum plasma detomidine concentration after GEL was 2.1 ± 1.2 ng mL^?1 (mean ±SD) and the time of maximum concentration was 66.0 ± 36.9 minutes. The bioavailability of detomidine was approximately 34% with GEL. Similar sedation scores were reached in both groups after administration of detomidine, but maximal sedation was reached earlier in the IV group (10 minutes) than in the GEL group (40 minutes). HR was lower after IV than GEL from 5 to 10 minutes after administration. All animals were adequately sedated, and we were able to administer local anaesthetic without resistance to all of the calves before disbudding.Conclusions and clinical relevanceOromucosally administered detomidine is an effective sedative agent for calves prior to disbudding.     

Ranking of physiotherapeutic evaluation methods as outcome measures of stifle functionality in dogs

Background

Various physiotherapeutic evaluation methods are used to assess the functionality of dogs with stifle problems. Neither validity nor sensitivity of these methods has been investigated. This study aimed to determine the most valid and sensitive physiotherapeutic evaluation methods for assessing functional capacity in hind limbs of dogs with stifle problems and to serve as a basis for developing an indexed test for these dogs. A group of 43 dogs with unilateral surgically treated cranial cruciate ligament deficiency and osteoarthritic findings was used to test different physiotherapeutic evaluation methods. Twenty-one healthy dogs served as the control group and were used to determine normal variation in static weight bearing and range of motion.The protocol consisted of 14 different evaluation methods: visual evaluation of lameness, visual evaluation of diagonal movement, visual evaluation of functional active range of motion and difference in thrust of hind limbs via functional tests (sit-to-move and lie-to-move), movement in stairs, evaluation of hind limb muscle atrophy, manual evaluation of hind limb static weight bearing, quantitative measurement of static weight bearing of hind limbs with bathroom scales, and passive range of motion of hind limb stifle (flexion and extension) and tarsal (flexion and extension) joints using a universal goniometer. The results were compared with those from an orthopaedic examination, force plate analysis, radiographic evaluation, and a conclusive assessment. Congruity of the methods was assessed with a combination of three statistical approaches (Fisher’s exact test and two differently calculated proportions of agreeing observations), and the components were ranked from best to worst. Sensitivities of all of the physiotherapeutic evaluation methods against each standard were calculated.

Results

Evaluation of asymmetry in a sitting and lying position, assessment of muscle atrophy, manual and measured static weight bearing, and measurement of stifle passive range of motion were the most valid and sensitive physiotherapeutic evaluation methods.

Conclusions

Ranking of the various physiotherapeutic evaluation methods was accomplished. Several of these methods can be considered valid and sensitive when examining the functionality of dogs with stifle problems.     

Plasma drug concentrations and clinical effects of a peripheral alpha‐2‐adrenoceptor antagonist,MK‐467, in horses sedated with detomidine

ObjectiveTo investigate plasma drug concentrations and the effect of MK-467 (L-659′066) on sedation, heart rate and gut motility in horses sedated with intravenous (IV) detomidine.Study designExperimental randomized blinded crossover study.AnimalsSix healthy horses.MethodsDetomidine (10 μg kg^?1 IV) was administered alone (DET) and in combination with MK-467 (250 μg kg^?1 IV; DET + MK). The level of sedation and intestinal sounds were scored. Heart rate (HR) and central venous pressure (CVP) were measured. Blood was collected to determine plasma drug concentrations. Repeated measures anova was used for HR, CVP and intestinal sounds, and the Student's t-test for pairwise comparisons between treatments for the area under the time-sedation curve (AUC_sed) and pharmacokinetic parameters. Significance was set at p < 0.05.ResultsA significant reduction in HR was detected after DET, and HR was significantly higher after DET + MK than DET alone. No heart blocks were detected in any DET + MK treated horses. DET + MK attenuated the early increase in CVP detected after DET, but later the CVP decreased with both treatments. Detomidine-induced intestinal hypomotility was prevented by MK-467. AUC_sed was significantly higher with DET than DET + MK, but maximal sedations scores did not differ significantly between treatments. MK-467 lowered the AUC of the plasma concentration of detomidine, and increased its volume of distribution and clearance.Conclusions and clinical relevanceMK-467 prevented detomidine induced bradycardia and intestinal hypomotility. MK-467 did not affect the clinical quality of detomidine-induced sedation, but the duration of the effect was reduced, which may have been caused by the effects of MK-467 on the plasma concentration of detomidine. MK-467 may be useful clinically in the prevention of certain peripheral side effects of detomidine in horses.     

Effect of MK‐467 on organ blood flow parameters detected by contrast‐enhanced ultrasound in dogs treated with dexmedetomidine

ObjectiveTo evaluate the dexmedetomidine‐induced reduction in organ blood flow with quantitative contrast‐enhanced ultrasound (CEUS) method and to observe the influence of MK‐467 on such reduction.Study designRandomized cross‐over study.AnimalsSix adult purpose‐bred laboratory beagle dogs (mean body weight 15.3 ± 1.9 kg).MethodsContrast‐enhanced ultrasound was performed on six conscious healthy laboratory beagles. The animals on separate occasions underwent three treatments: awake without any medication (CTRL), dexmedetomidine 10 μg kg^?1 (DEX) and DEX + MK‐467 500 μg kg^?1 (DMK) intravenously (IV). The kidney (10–15 minutes post‐treatment), spleen (25–30 minutes post‐treatment), small intestine (40–45 minutes post‐treatment) and liver (50–55 minutes post‐treatment) were examined with CEUS. A time curve was generated and the following perfusion parameters were analysed: arrival time (AT), time to peak from injection (TTPinj), peak intensity (PI) and wash‐in rate (Wi). In addition to CEUS, renal glomerular filtration rate was indirectly estimated by the rate of iohexol elimination.ResultsAT and TTPinj were significantly higher for DEX than for CTRL in all studied organs. The same parameters were significantly higher for DEX than for DMK in the kidney, spleen and small intestine. PI was significantly lower for DEX than for CTRL or DMK in the kidney. Wi was significantly lower for DEX than for CTRL or DMK in the kidney and significantly lower than for CTRL only in the small intestine. Plasma concentration of iohexol was significantly higher after DEX than CTRL administration.ConclusionsContrast‐enhanced ultrasound was effective in detecting DEX‐induced changes in blood flow. MK‐467 attenuated these changes.Clinical relevanceClinicians should consider the effects of the sedation protocol when performing CEUS. Addition of MK‐467 might beneficially impact the haemodynamic function of sedation with alpha‐2 adrenoceptor agonists.     

Germination of Oat and Quinoa and Evaluation of the Malts as Gluten Free Baking Ingredients

Germination can be used to improve the sensory and nutritional properties of cereal and pseudocereal grains. Oat and quinoa are rich in minerals, vitamins and fibre while quinoa also contains high amounts of protein of a high nutritional value. In this study, oat and quinoa malts were produced and incorporated in a rice and potato based gluten free formulation. Germination of oat led to a drastic increase of α-amylase activity from 0.3 to 48 U/g, and minor increases in proteolytic and lipolytic activities. Little change was observed in quinoa except a decrease in proteolytic activity from 9.6 to 6.9 U/g. Oat malt addition decreased batter viscosities at both proofing temperature and during heating. These changes led to a decrease in bread density from 0.59 to 0.5 g/ml and the formation of a more open crumb, but overdosing of oat malt deteriorated the product as a result of excessive amylolysis during baking. Quinoa malt had no significant effect on the baking properties due to low α-amylase activity. Despite showing a very different impact on the bread quality, both malts influenced the electrophoretic patterns of rice flour protein similarly. This suggests that malt induced proteolysis does not influence the technological properties of a complex gluten free formulation.