Comparison of the cardiopulmonary parameters after induction of anaesthesia with alphaxalone or etomidate in dogs

ObjectiveTo compare the cardiorespiratory effects and quality of induction of and recovery from anaesthesia following etomidate or alphaxalone-HPCD IV.Study designRandomized ‘blinded’ cross-over study. Twenty-four hours was allowed between phases.AnimalsEight healthy adult Beagles (four male, four female).MethodsDogs were anaesthetized with sevoflurane for instrumentation, then allowed to awake. They then received etomidate (treatment E) or alphaxalone-HPCD (treatment A) intravenously to effect. Heart rate (HR), body temperature, invasive arterial pressures (AP), systemic vascular resistance index (SVRI), stroke volume index, cardiac index (CI), contractility, respiratory rate, central venous pressure, and capnometry were obtained before anaesthetic induction (baseline), 30 seconds and 1 minute after induction, after intubation, one minute after intubation, and for every 5 minutes afterwards until the dog began to swallow and the trachea was extubated. Arterial bloods were taken for analyses before induction, after intubation and every 10 minutes thereafter. The dogs breathed room air. The quality of induction of and recovery from anaesthesia were scored categorically. Statistical analyses used anova for repeated measures, paired t-tests or Wilcoxon signed rank-test as relevant. Significance was set at p < 0.05.ResultsThe induction doses required were (mean ± SD) 2.91 ± 0.41 mg kg^?1 and 4.15 ± 0.7 mg kg^?1 for treatment E and A respectively. No significant changes in cardiovascular parameters were observed with treatment E. Treatment A resulted in statistically significant increases in HR and CI and reductions of APs and SVRI. Time to extubation was longer with treatment A (25 ± 7 minutes) than with treatment E (17 ± 4 minutes). Dogs became hypoxic with both treatments. The quality of induction and recovery were excellent with treatment A, but significantly less satisfactory with treatment E (recovery score, treatment E median 1, range 0–2; treatment A median 0, range 0–1).Conclusions and clinical relevanceAlphaxalone-HPCD caused significant tachycardia and increase in CI, and statistically (but not clinically) significant decreases in APs and SVRI. Etomidate caused no statistically significant cardiovascular changes. Quality of recovery was better with alfaxalone-HPCD. Both agents caused short-lived hypoxia, and oxygen supplementation is advisable.     

Crocetin esters, picrocrocin and its related compounds present in Crocus sativus stigmas and Gardenia jasminoides fruits. Tentative identification of seven new compounds by LC-ESI-MS

Crocetin esters present in saffron (Crocus sativus L.) stigmas and in Gardenia jasminoides Ellis fruit are the compounds responsible for their color. Of the fifteen crocetin esters identified in this study, five new compounds were tentatively identified: trans and cis isomers of crocetin (beta-D-triglucoside)-(beta-D-gentibiosyl) ester, trans and cis isomers of crocetin (beta-D-neapolitanose)-(beta-D-glucosyl) ester, and cis crocetin (beta-D-neapolitanose)-(beta-D-gentibiosyl) ester. The most relevant differences between both species were a low content of the trans crocetin (beta-D-glucosyl)-(beta-D-gentibiosyl) ester, the absence of trans crocetin di-(beta-D-glucosyl) ester in gardenia, and its higher content of trans crocetin (beta-D-gentibiosyl) ester and cis crocetin di-(beta-D-gentibiosyl) ester. With the same chromatographic method it was possible to identify, in a single run, ten glycosidic compounds in saffron extracts with a UV/vis pattern similar to that of picrocrocin; among them, 5-hydroxy-7,7-dimethyl-4,5,6,7-tetrahydro-3H-isobenzofuranone 5-O-beta-D-gentibioside and 4-hydroxymethyl-3,5,5-trimethyl-cyclohexen-2-one 4-O-beta-D-gentibioside were tentatively identified for the first time in saffron. Of these ten glycosides, only the O-beta-D-gentibiosyl ester of 2-methyl-6-oxo-2,4-hepta-2,4-dienoic acid was found in gardenia samples, but it was possible to identify the iridoid glycoside, geniposide.     

Ultrastructural changes and structure and mobility of myowater in frozen-stored hake (Merluccius merluccius L.) muscle: relationship with functionality and texture

The ultrastructural changes and the main Raman spectral features of water (3100-3500 and 50-600 cm(-)(1) ranges) in frozen-stored hake were studied with the aim of connecting these changes with loss of some functional properties such as water holding capacity, and with modifications of muscle texture. The following results were obtained: (a) The changes in the spaces between myofibrils can be related to modifications of shear resistance. (b) The behavior of the strong 160 cm(-)(1) band can be related to conformational transitions of muscle proteins, to changes in the structure of muscle water, and/or to alterations in protein-water interactions. (c) There were intensity changes in the nu(s)(OH) band that may be attributable to transfer of water to larger spatial domains during frozen storage.     

Humic substances increase the effectiveness of iron sulfate and Vivianite preventing iron chlorosis in white lupin

The main objective of this work was to study the influence of humic substances (HS) on the effectiveness of Fe sulfate and Vivianite in preventing Fe chlorosis in white lupin with a view of performing cost-effective methods to overcome the problem. Two consecutive crops were performed using calcareous sand treated with different Fe sources (FeSO₄·7H₂O and Vivianite, at three different rates, and Fe-EDDHA) and five HS rates. Vivianite was more effective and persistent than Fe sulfate in increasing Soils and Plant Analysis Development (SPAD) readings and lupin yield expressed as dry matter (DM), probably due to the type of alteration products formed upon Vivianite oxidation. The effect of Fe sulfate and Vivianite in preventing Fe chlorosis was significantly increased by HS, and the best results were obtained with Vivianite and HS applied at 0.32 g Fe kg⁻¹ and 0.06 g kg⁻¹ growing media, respectively. SPAD readings with this treatment accounted for 85% and 70% of those obtained with Fe-EDDHA in the first and second crop, respectively, whereas DM production was greater with the Vivianite + HS treatment than with Fe-EDDHA. These results showed the potential effectiveness of treatments based on the application of Vivianite and HS in overcoming Fe chlorosis. However, HS applied with Fe sources at rates of 0.5 and 1 g kg⁻¹ growing media decreased SPAD readings and plant yield. These positive and negative effects of HS in preventing Fe chlorosis were more evident with Fe sulfate and Vivianite than with chelated Fe, probably due to the effect of HS on the solubility of Fe forms of the growing medium.     

Structural and environmental characterization of old-growth temperate rainforests of northern Chiloé Island,Chile: Regional and global relevance

Old-growth forests are ecologically relevant reservoirs of biodiversity and provide valuable and unique ecosystem functions in the landscape. However, what constitutes an old-growth stand is confusing because the definition depends largely on the forest type under study. Despite the ecological importance of old-growth temperate rainforests in southern Chile in comparison to other global forests, no attempts have been made to characterize them as a way to assess their structural variability. Here, we characterized old-growth stands of Valdivian and North Patagonian rain forest types located in Chiloé Island (Chile, 42°30′S) using inventory data from 23 permanent plots (0.1 ha each) located in rural landscapes and protected areas of northern Chiloé Island. For each stand, its age (average age of the oldest trees present in each stand) and disturbance regimes (evidence of recent human impact, e.g. cuttings or fires, and tree growth rates) were used as defining old-growth criteria. We characterized the structure (tree species richness, size-density distributions, vertical stratification and presence of snags) and floristic composition of each stand. Environmental variables (i.e. temperature, distance to coastline and elevation) were related to stand structure using multivariate constrained correspondence analysis. Old-growth forests were commonly characterized by (a) tree basal areas >80 m²/ha; (b) density of shade-tolerant tree species in the emergent and dominant canopy layer >36%; (c) higher tree species richness (>7 tree species) than successional stands; (d) presence of large canopy emergents (>80 cm dbh, >25 m tall); (e) high vertical heterogeneity; and (f) minimum stand ages older than 200 years. Old-growth forests showed a distinctive structural variability and floristic diversity influenced both by stand age and disturbance history of the stands. Structural variability was also related to environmental differences among sites (e.g. air temperature, distance to coastline, soil types). Old-growth forest features described here can offer a baseline for managers interested in maintaining and restoring old-growth forest structure in southern temperate rain forests.     

Kinetics of individual crocetin ester degradation in aqueous extracts of saffron (Crocus sativus L.) upon thermal treatment in the dark

Kinetics of individual crocetin ester degradation in aqueous extracts of saffron upon thermal treatment in the dark has been studied. Special attention has been paid to the comparison between saffron extracts and aqueous solutions of a crocetin ester rich fraction, with a lower stability of the latter observed. The degradation reaction was the same for all crocetin esters whether they were in saffron extracts or whether they were purified, although it was affected by external factors that modified their kinetic and thermodynamic parameters, making some of them less stable than others.     

A multi-criteria approach to identify favorable areas for goat production systems in Veracruz,México

This research identifies favorable areas for goat production systems in the state of Veracruz, Mexico. Through the use of the analytic hierarchy process, layers of biophysical and soil information were combined to generate a model of favorability. Model validation was performed by calculating the area under the curve, the true skill statistic, and a qualitative comparison with census records. The results showed the existence of regions with high (4494.3 km²) and moderate (2985.8 km²) favorability, and these areas correspond to 6.25 and 4.15%, respectively, of the state territory and are located in the regions of Sierra de Huayacocotla, Perote, and Orizaba. These regions are characterized as mountainous and having predominantly temperate-wet or cold climates, and having montane mesophilic forests, containing pine, fir, and desert scrub. The reliability of the distribution model was supported by the area under the curve value (0.96), the true skill statistic (0.86), and consistency with census records.