The effects of restriction of movement on the reliability of heart rate variability measurements in the horse (Equus caballus)

Analysis of heart rate variability (HRV) is a noninvasive approach for investigating the sympathovagal balance of the autonomic nervous system. In recent years, HRV has been increasingly evaluated in animal research. In horses, it has been suggested that basal resting conditions can be achieved by restraining them. The aim of this study was to verify how restriction of movement influences HRV i2n horses. Ten healthy standardbred mares were used to measure the electrocardiographic signal under 2 conditions: free to move in the stall and restrained in the stock. Results indicate that the restriction of movement is associated with increased nervous system sympathetic activity not consistent with resting conditions.     

Thromboelastography platelet mapping in healthy dogs using 1 analyzer versus 2 analyzers

The objective of this study was to describe the results of thromboelastography platelet mapping (TEG-PM) carried out using 2 techniques in 20 healthy dogs. Maximum amplitudes (MA) generated by thrombin (MA_thrombin), fibrin (MA_fibrin), adenosine diphosphate (ADP) receptor activity (MA_ADP), and thromboxane A₂ (TxA₂) receptor activity (stimulated by arachidonic acid, MA_AA) were recorded. Thromboelastography platelet mapping was carried out according to the manufacturer’s guidelines (2-analyzer technique) and using a variation of this method employing only 1 analyzer (1-analyzer technique) on 2 separate blood samples obtained from each dog. Mean [± standard deviation (SD)] MA values for the 1-analyzer/2-analyzer techniques were: MA_thrombin = 51.9 mm (± 7.1)/52.5 mm (± 8.0); MA_fibrin = 20.7 mm (± 21.8)/23.0 mm (± 26.1); MA_ADP = 44.5 mm (± 15.6)/45.6 mm (± 17.0); and MA_AA = 45.7 mm (± 11.6)/45.0 mm (± 15.4). Mean (± SD) percentage aggregation due to ADP receptor activity was 70.4% (± 32.8)/67.6% (± 33.7). Mean percentage aggregation due to TxA₂ receptor activity was 77.3% (± 31.6)/78.1% (± 50.2). Results of TEG-PM were not significantly different for the 1-analyzer and 2-analyzer methods. High correlation was found between the 2 methods for MA_fibrin [concordance correlation coefficient (r) = 0.930]; moderate correlation was found for MA_thrombin (r = 0.70) and MA_ADP (r = 0.57); correlation between the 2 methods for MA_AA was lower (r = 0.32). Thromboelastography platelet mapping (TEG-PM) should be further investigated to determine if it is a suitable method for measuring platelet dysfunction in dogs with thrombopathy.     

Variability in in vitro macrophage activation by commercially diverse bulk echinacea plant material is predominantly due to bacterial lipoproteins and lipopolysaccharides

We previously reported that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea and other botanicals depends upon bacterial lipopolysaccharides and Braun-type bacterial lipoproteins. We determined the contribution made by these bacterial components to the overall immune-enhancing activity detected in E. purpurea and E. angustifolia bulk root and aerial material obtained from six major growers/suppliers in North America. Substantial variation in activity (up to 200-fold) was observed in extracts of these materials when tested in two monocyte/macrophage cell lines. The majority of activity was negated by treatment with agents that target bacterial lipoproteins (lipoprotein lipase) and lipopolysaccharides (polymyxin B). Experiments comparing the activity of freeze-dried, freshly harvested Echinacea plants to those harvested and dried using various commercially relevant conditions suggest that postharvesting procedures do not substantially contribute to the variation observed in the commercial material.     

Integrating land cover structure and functioning to predict biodiversity patterns: a hierarchical modelling framework designed for ecosystem management

Context

Land-use/land-cover (LU/LC) dynamics is one of the main drivers of global environmental change. In the last years, aerial and satellite imagery have been increasingly used to monitor the spatial extent of changes in LU/LC, deriving relevant biophysical parameters (i.e. primary productivity, climate and habitat structure) that have clear implications in determining spatial and temporal patterns of biodiversity, landscape composition and ecosystem services.

Objectives

An innovative hierarchical modelling framework was developed in order to address the influence of nested attributes of LU/LC on community-based ecological indicators.

Methods

Founded in the principles of the spatially explicit stochastic dynamic methodology (StDM), the proposed methodological advances are supported by the added value of integrating bottom-up interactions between multi-scaled drivers.

Results

The dynamics of biophysical multi-attributes of fine-scale subsystem properties are incorporated to inform dynamic patterns at upper hierarchical levels. Since the most relevant trends associated with LU/LC changes are explicitly modelled within the StDM framework, the ecological indicators’ response can be predicted under different social-economic scenarios and site-specific management actions. A demonstrative application is described to illustrate the framework methodological steps, supporting the theoretic principles previously presented.

Conclusions

We outline the proposed multi-model framework as a promising tool to integrate relevant biophysical information to support ecosystem management and decision-making.

     

Duration of Anthelmintic Effect of Three Formulations of Ivermectin (Oral,Injectable and Pour-on) Against Multiple Anthelmintic-Resistant <Emphasis Type="Italic">Haemonchus contortus</Emphasis> in Sheep

We report the results of investigations that were conducted in a sheep flock in Uttaranchal, India where repeated failure of anthelmintic medication was noted. The study revealed that Haemonchus contortus in sheep had developed resistance to benzimidazoles (fenbendazole, mebendazole and albendazole), imidazothiazole (levamisole) and salicylanide (rafoxanide), while it was fully susceptible to avermectins (ivermectin). Further, the suppression of nematode egg output in faeces of sheep naturally infected with multiple anthelmintic-resistant H. contortus following treatment with ivermectin tablet (0.4 mg/kg body weight (bw), orally), ivermectin injection (1% w/v, 0.2 mg/kg bw, subcutaneously) and ivermectin pour-on (0.5 w/v, 0.5 mg/kg bw) was also studied over a period of 10 weeks post treatment. It was noted that ivermectin tablet after initial clearance of infection (faecal egg count reduction 100%), could not prevent establishment of new patent natural infection for even a single day, while ivermectin pour-on and injection prevented the establishment of new infection for 7 and 14 days post treatment, respectively. Maximum protection period (duration for which mean faecal egg count of sheep reaches 500 eggs per gram of faeces or more) of 68 days was recorded in sheep treated with injectable ivermectin, followed by pour-on (60 days) and oral (53 days) preparations.     

Comparison of 99mTcO4(-) trans-splenic portal scintigraphy with per-rectal portal scintigraphy for diagnosis of portosystemic shunts in dogs

Objective— To evaluate trans-splenic portal scintigraphy (TSPS) and per-rectal portal scintigraphy (PRPS) for diagnosis of congenital portosystemic shunts (CPSS) in dogs, and compare these results with surgical findings.
Study Design— Prospective, randomized cross over clinical trial.
Animals— Dogs (n=42) with suspected CPSS.
Methods— Dogs had TSPS and PRPS 48 hours apart; quantity of radionuclide administered was recorded. Three independent, blinded reviewers evaluated each scintigraphic study for study quality, shunt presence, number, and location of shunt termination (caudal vena cava, azygos vein). All dogs had exploratory celiotomy. Negative scintigraphic findings were confirmed with intraoperative mesenteric portography. Ameroid constrictors were placed on all extrahepatic CPSS, and hepatic biopsies were obtained.
Results— TSPS was 100% sensitive and specific for diagnosis of CPSS and significantly ( P <.05) more likely than PRPS to detect shunt number and termination. Interpretation was consistent between observers, and TSPS required significantly less radionuclide than PRPS.
Conclusion— TSPS was as sensitive as PRPS for detection of shunting vessels, and consistently yielded studies of higher quality, allowing detection of shunt number and location with consistent interpretation among radiologists.
Clinical Relevance— TSPS provides information about shunt number and location, which allows improved surgical planning. Because it requires significantly less radionuclide, TSPS improves safety, allows for more comprehensive patient care, and earlier surgical intervention.     

Environmental impact of razor clam harvesting using salt in Ria Formosa lagoon (Southern Portugal) and subsequent recovery of associated benthic communities

• 1. Razor clams are found in different habitats ranging from sheltered systems (e.g. lagoons and estuaries) to open coasts. They are distributed worldwide and comprise a small number of species of high economic value. Depending on the specific habitat and species exploited, different mechanical and hand‐harvesting techniques are employed. While the environmental effects resulting from mechanized methods have been described by several authors, the impacts caused by traditional hand‐harvesting methods remain unknown. Therefore, a study was undertaken in Ria Formosa lagoon (South of Portugal) addressing the environmental effects resulting from harvesting Solen marginatus with salt.
• 2. No significant impact on the sediment was found; the main effect was an increase in salinity after covering the area with salt, which decreased rapidly with the flood tide and after a few hours had returned to pre‐harvesting levels.
• 3. No effects on benthic communities were observed, with similar fluctuation patterns recorded in control and experimental areas, the observed differences being attributed to the natural variability of benthic populations.
• 4. Based on the results obtained in the present study, a razor clam fishery using salt in intertidal areas can be considered environmentally ‘friendly’.

Copyright © 2008 John Wiley & Sons, Ltd.