A comparison of the analgesic effects of caudal epidural methadone and lidocaine in the horse

Objective To evaluate and compare the effects of caudal epidural administration of methadone (METH) and lidocaine (LIDO) on tolerance to thermal stimulation over the dermatomes of the perineal, sacral, lumbar and thoracic regions in the horse. Study design A blinded, randomized, prospective, experimental cross‐over study. Animals Seven healthy horses, 15.7 ± 4.9 years (mean ± SD) of age, weighing 536 ± 37 kg. Methods The horses were randomly assigned to receive two treatments (group M: METH, 0.1 mg kg^?1 or group L: LIDO, 0.35 mg kg^?1) at intervals of at least 28 days. An 18‐gauge 80‐mm Tuohy epidural needle was placed in the first intercoccygeal space (Co1–Co2) in awake standing horses restrained in stocks. Analgesia was assessed by use of a probe maintained at a constant 62 °C by circulating hot water. The maximum stimulation time was 30 seconds. Bilateral stimulation was performed at five defined points. Before drug administration, baseline values of response time to thermal stimuli were obtained. Time to response was then measured 15 and 60 minutes after METH or LIDO administration and then hourly until the response returned to baseline at all stimulation points on two further assessments. Development of any ataxia and/or sedation was recorded. Positive pain responses were defined as purposeful avoidance movements of the head, neck, trunk, limbs and tail. Absence of attempts to kick, bite and turning of the head toward the stimulation site were used to indicate analgesia. Results Caudal epidural administration of METH and LIDO significantly increased reaction time to thermal stimulation (one‐sample t‐test; p = 0.05). Analgesia in the perineal region was present 15 minutes after both METH and LIDO administration and progressed from caudal to cranial dermatones with time. The duration of a significant increase in reaction time was 5 hours after METH injection compared to 3 hours following LIDO. All horses defaecated and urinated normally, and no excitement, sedation or ataxia were observed after METH administration. The horses were unable to defaecate normally and were moderately to severely ataxic with hindlimb weakness after LIDO. Conclusions Caudal epidural administration of methadone has considerable potential in the management of perineal, lumbo‐sacral and thoracic pain in horses. Regional differences exist in the onset, duration and intensity of the pain relief. Clinical relevance Epidural methadone administration provides analgesia with no measured side effects in these healthy adult horses.     

Influence of feeding malt, bread crust, and a pronylated protein on the activity of chemopreventive enzymes and antioxidative defense parameters in vivo

The aim of the present study was to investigate whether feeding of malt, bread crust, and a pronylated albumin modulates chemoprevention enzymes, such as glutathione-S-transferase (GST) and UDP-glucuronyl-transferase (UDP-GT), and antioxidative defense parameters in vivo and whether the intake of these foods rich in Maillard reaction compounds results in an accumulation of compounds formed in in vivo glycation reactions. After quantitation of pronylated lysine in malt and bread crust, male Wistar rats were fed a standard chow supplemented with 28% of protein containing different amounts of casein, bread crust, caraffa malt, or pronyl bovine serum albumin (BSA) for 15 days. GST activity in the kidneys was increased by 18% (p > 0.05) in animals of the bread crust group, while UDP-GT activity was elevated by 27% in the liver of animals administered pronyl-BSA. Contents of tocopherol in plasma were increased by 33, 14, and 14% in the bread crust, malt, and pronyl-BSA group compared to the control group, while the levels of thiobarbituric acid reactive substances were decreased and the total antioxidant capacity was increased. Parameters of endogenous glycation indicated a 32 and 46% higher load of advanced glycation end products in the kidneys after administration of the malt and the pronyl-BSA containing diet. However, the main systemic effects of dietary malt, bread crust, and pronyl-BSA were, for the first time, demonstrated to be the enhanced antioxidant capacity and the particulate increase in chemopreventive enzymes.     

Effect of different levels of mannan‐oligosaccharide supplementation on the apparent ileal digestibility of nutrients,N‐balance and growth performance of weaned piglets

Several studies report that dietary mannan‐oligosaccharides (MOSs) improve the growth performance of piglets, however, only a few studies focus on nutrient digestibility. The aim of the study was to investigate the effect of dietary MOS on ileal digestibility of nutrients and on N‐balance and growth performance of piglets weaned at 28 days of age. Three experiments were conducted: a digestibility trial with a total of 30, simple T‐cannulated piglets (Exp. 1), a N‐balance trial with a total of 48 intact piglets (Exp. 2) and a performance trial with a total of 324 piglets (Exp. 3). In Exp. 1 and 2, the same five dietary treatments were carried out by supplementing the basal diet with 0, 1, 2, 4 g MOS or with 0.2 g antibiotic growth promoter (AGP, Avilamycin) per kg of diet. In Exp. 3, three dietary treatments were used as follows: the basal diet was supplemented no additive, 2 g MOS or 0.2 g AGP (Avilamycin) per kg of diet. Dietary MOS (2 or 4 g/kg) enhanced the ileal digestibility of crude protein similar to antibiotics. Addition of 1 g/kg MOS significantly increased the digestibility of Ca and P by 8.4% and 7.7% units, respectively; however, further increment did not enhance the absorption. Addition of 1 or 2 g/kg MOS significantly increased the ileal digestibility of lysine, methionine, cystine and threonine with the same magnitude or even more than the AGP. In our study, MOS supplementation had no influence on N‐balance and growth parameters. Because of the better apparent ileal digestibility of certain nutrients, however, the protein, lysine, methionine, cystine, threonine, Ca and P contents of the diet can probably be reduced without weakening the rearing performance of piglets, when the diet is supplemented with 2 g/kg MOS.     

Biochemical parameters in Tubifex tubifex as an integral part of complex sediment toxicity assessment

Background, aim, and scope

Restoration of lakes and reservoirs with extensive cyanobacterial water bloom often requires evaluation of the sediment quality. Next to the chemical analysis of known pollutants, sediment bioassays should be employed to assess toxicity of the present contaminants and to make predictions of associated risk. Brno reservoir in the Czech Republic is a typical example of water bodies with long-term problems concerning cyanobacterial water blooms. Comprehensive assessment of reservoir sediment quality was conducted since successful reservoir restoration might require sediment removal. An important part of this survey focused on an examination of the utility of Tubifex tubifex and its sublethal biochemical markers for the assessment of direct sediment toxicity.

Materials and methods

This complex study included chemical analysis of contaminants (heavy metals, organic pollutants), ecotoxicity testing of sediment elutriates (tests with Daphnia magna, Pseudomonas putida, Sinapis alba, Scenedesmus subspicatus), and other parameters. We have tested in more detail the applicability of T. tubifex as a test organism for direct evaluation of contact sediment toxicity. Survival tests after 14 days of exposure were complemented by an assessment of parameters serving as biomarkers for sublethal effects [such as total glutathione content (GSH), activities of the enzymes glutathione transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR)]. The data matrix was subjected to multivariate analysis to interpret relationships between different parameters and possible differences among locations.

Results

The multivariate statistical techniques helped to clearly identify the more contaminated upstream sites and separate them from the less contaminated and reference samples. The data document closer relationships of the detected sediment contamination with results of direct sediment exposure in the T. tubifex test regarding mortality but namely regarding the sublethal endpoints rather than the results obtained with other test organisms exposed to sediment elutriates. Aside from the reduction in T. tubifex survival, the sediments with organic pollution caused an increase in glutathione content and increased activities of glutathione S-transferase and glutathione peroxidase in the exposed T. tubifex worms.

Discussion

Results of our study confirm the suitability of T. tubifex for toxicity testing of raw waters and sediments. This longer-lasting direct contact test has proven more sensitive and appropriate to reflect a lower level of pollution than do the elutriate tests. Sensitive biochemical changes in T. tubifex, including an elevation in GSH levels and GST activities, reflect a general stimulation of detoxification metabolisms in the presence of xenobiotics. The results also suggest an important role of glutathione and related enzymes in detoxification processes and possible involvement of oxidative stress in toxicity mechanisms in benthic sediment-dwelling worms such as T. tubifex.

Conclusions

The complex assessment has identified the more contaminated samples with locally increased concentration of organic pollutants and significant ecotoxicity. The direct sediment contact test with T. tubifex and especially the biochemical parameters corresponded better to the lower level of pollution than the other tests with sediment elutriates. Despite its greater time and cost demands, the direct sediment contact test can provide a more realistic picture of exposure.

Recommendations and perspectives

Sediment bioassays should always be included as an integral part of the sediment quality assessment. The direct contact tests also take into account the more hydrophobic pollutants that are not easily available for the water elution but can still be accessible to the organisms. The T. tubifex test is a suitable option for contact sediment toxicity tests also because these animals show measurable sublethal biochemical changes that can be associated with this exposure.     

Genetic differentiation between local populations of Ips typographus in the high Tatra Mountains range

Many studies have addressed the question of dispersal potential of Ips typographus, however the approach of molecular ecology have been used only in a few of them. Moreover, none of them has done it on fine scale of just one mountain range. Molecular analysis using a set of six polymorphic microsatellite markers was applied in this study. Adult beetles of I. typographus collected in 22 localities of the High Tatra Mountains were used for the study of genetic differentiation between rapidly expanded local populations of bark beetles after windstorm calamities in spruce stands. Almost none genetic differentiation among local populations or among larger spatial units has been revealed. Analyses did not indicate isolation of populations by distance or formation of population structure. This suggests high potential of I. typographus to disperse over large distances and even the possibility to overcome high mountains ridges.     

Impact of thermal modification on color and chemical changes of spruce and oak wood

Thermal modification of wood is an environment-friendly alternative method for improving several properties of wood without the use of chemicals. This paper deals with the examination of color and chemical changes in spruce (Picea abies L.) and oak wood (Quercus robur F.) that occur due to thermal treatment. The thermal modification was performed at 160, 180, and 210 °C according to thermowood process. The color changes were measured by the spectrophotometer and described in the L*a*b* color system. Chemical changes were examined by wet chemistry methods, infrared spectroscopy and liquid chromatography. During the experiment, oak samples showed smaller color changes than spruce samples at all temperature values. During thermal modification, the content of cellulose, lignin, and extractives increases; however, the hemicellulose content drops by 58.85% (oak) and by 37.40% (spruce). In addition to deacetylation, new carbonyl and carboxyl groups are formed as a result of oxidation. Bonds in lignin (mainly β-O-4) and methoxyl groups are cleaved, and lignin is condensed at higher temperatures.     

Effect of leached cement paste samples with different superplasticiser content on germination and initial root growth of white mustard (<Emphasis Type="Italic">Sinapis alba</Emphasis>) and cress (<Emphasis Type="Italic">Lepidium sativum</Emphasis>)

With an annual production of about 10 Gt concrete is by far the most used solid man-made material. In order to adjust the workability of fresh concrete most often so-called superplasticisers, essentially water-soluble organic polymers, are utilised. As concrete is commonly in direct contact with soil or water, the leaching of organic and inorganic compounds and their environmental impact need to be assessed. The present study contributes to this purpose by investigating leachates from hardened cement pastes gained using the horizontal dynamic surface leaching test. Pastes were prepared with and without superplasticiser. The root growths as well as the germination behaviour of cress (Lepidium sativum) and white mustard (Sinapis alba) were examined with respect to phytotoxicity. Different proportions (100, 50, 25 and 12.5%) of the leachates were considered in the test scheme. The results indicate a positive effect of most of the leachates on seed germination and root growth, although statistical significance was only found in some cases. Both test species showed no or only slight harmful effects as relative root growth exceeded always 66% for S. alba and 74% for L. sativum. Seed germination was not negatively influenced by the leachates. Slight beneficial effects on both test species could be observed for leachates containing superplasticiser compared to samples in absence of superplasticiser.     

Radiographic and ultrasonographic diagnosis of stenosing tenosynovitis of the abductor pollicis longus muscle in dogs

Stenosing tenosynovitis of the abductor pollicis longus muscle causes chronic front limb lameness in dogs. The lesion, similar to de Quervain's tenosynovitis in people, is caused by repetitive movements of the carpus. Thirty dogs with front limb lameness, painful carpal flexion, and a firm soft tissue swelling medial to the carpus were examined prospectively. Seven dogs had bilateral abductor pollicis longus tenosynovitis. Radiographs of the carpus were characterized by a deeper radiolucent medial radial sulcus and bony proliferations medial and slightly cranial to the distal radius, resulting in stenosis of the tendon sheath and subsequent tendinitis. Ultrasonographic examination of the firm soft tissue swelling medial to the carpus was characterized by an irregular hypoechoic abductor pollicis longus tendon or tendinitis in 22 of 37 dogs. Nineteen of 37 abductor pollicis longus tendon sheaths were fluid-filled and all tendon sheaths were thickened, more hyperechoic, with small hyperechoic mineralizations embedded in the connective tissue of the abductor pollicis longus tendon sheath in 25 dogs. Enthesopathy of the abductor pollicis longus tendon was identified in seven dogs. While radiographs of stenosing tenosynovitis of the abductor pollicis longus are helpful in visualizing the deep radial sulcus and osteophytes medial to the distal radius, ultrasonography is useful to distinguish between lesions of the tendon or tendon sheath and to determine thickness and fluid content of the abductor pollicis longus tendon sheath.     

Biological control of helminths in grazing animals using nematophagous fungi

For the last 50 years the control of gastro-intestinal nematodes (GIN) in grazing animals has almost entirely been alleviated by the use of anthelmintics. Due to development of resistance against the drugs, especially in the GIN of sheep and goats it has become necessary to develop new, innovative strategies such as the use of nematode destroying fungi. Despite experiments to employ various species against plant and animal parasitic nematodes were already attempted in the 1930's, it was not until the 1990's when selection by simulating passage through the gastro-intestinal tract of cattle led to isolation of the fungus Duddingtonia flagrans that a major breakthrough was achieved. This fungus, producing sticky three-dimensional network and now isolated world-wide, is special due to its capacity to prolifically produce high numbers of thick-walled resting spores, chlamydospores. These spores survive passage through the gastro-intestinal tract of grazing livestock and are capable of growing and subsequently trap nematodes, including larval stages of parasitic nematodes. The great potential of this fungus as a biological control agent has been demonstrated through numerous trials with cattle, sheep, horses, and pigs. But these trials have also pointed towards some potential limitations in the activity spectrum of the fungus (Dictyocaulus, Nematodirus) beside the whole group of parasites spreading through infective stages protected inside resistant eggs (e.g. Ascaris, Trichuris). So far, in the few reported studies conducted, no negative environmental impact has been found, but it is important that further studies are conducted on this important issue. Although the potential use of D. flagrans chlamydospores has been verified through numerous trials it is necessary to develop practical delivery systems such as slow release devices, feed-blocks or similar to be able to implement this tool in future integrated control strategies. Such control strategies could include the use of biological control, grazing management, smart use of existing drugs, parasite resistant animal breeds, bioactive forages, and possibly vaccines.     

Individual administration of three tanniferous forage plants to lambs artificially infected with Haemonchus contortus and Cooperia curticei

We investigated direct anthelmintic effects associated with the feeding of fresh tanniferous forages against established populations of Haemonchus contortus and Cooperia curticei in lambs. Twenty-four parasite naive lambs were inoculated with a single dose of infective larvae of these two parasites 27 days prior to the start of the feeding experiment. Lambs were individually fed with either chicory (Cichorium intybus), birdsfoot trefoil (Lotus corniculatus), sainfoin (Onobrychis viciifolia) or a ryegrass/lucerne mixture (control) for 17 days. Animals where then united to one flock and subjected to control feeding for another 11 days to test the sustainability of potentially lowered egg excretion generated by tanniferous forage feeding. When compared to the control, administration of all tanniferous forages was associated with significant reductions of total daily faecal egg output specific to H. contortus (chicory: 89%; birdsfoot trefoil: 63%; sainfoin: 63%; all tests P<0.05) and a tendency of reduced H. contortus worm burden (chicory: 15%; birdsfoot trefoil: 49% and sainfoin: 35% reduction). Irrespective of the condensed tannin (CT) containing fodder, no anthelmintic effects were found against C. curticei. Cessation of CT-feeding followed by non-CT control feeding did not result in a re-emergence of faecal egg counts based on faecal dry matter (FECDM) in any group, suggesting that egg output reductions are sustainable. The moderate to high concentrations of CTs in birdsfoot trefoil (15.2 g CTs kg(-1) dry matter (DM)) and sainfoin (26.1 g CTs kg(-1) DM) were compatible with the hypothesis that the antiparasitic effect of these forages is caused by their content of CTs. For chicory (3 g CTs kg(-1) DM), however, other secondary metabolites need to be considered. Overall, birdsfoot trefoil and in particular sainfoin seem promising candidates in contributing to an integrated control strategy against H. contortus not only by mitigating parasite related health disturbances of the host but also by a sustained reduction of pasture contamination.