Effects of the anaesthetic associations atropine-tiletamine/zolazepam and atropine-ketamine/diazepam on adult emus (Dromaius novaehollandiae)

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0301-732X2009000200008&lang=ptEn el presente estudio se determinó el efecto de las asociaciones anestésicas atropina IM (0,05 mg/kg)-tiletamina/zolazepam EV (4 mg/kg total) y atropina IM (0,05 mg/kg-ketamina EV (5 mg/kg total)/diazepam (0,5 mg/kg) sobre la respuesta fisiológica, anestésica y bioquímica de emúes adultos. Los ejemplares (n = 7 por grupo) fueron asignados al azar a dos tratamientos anestésicos. La frecuencia cardiaca y la temperatura corporal de los emúes mostraron un incremento al inicio del tratamiento experimental (entre 5-10 min, P = 0,001). Sin embargo, la frecuencia respiratoria y pulso disminuyeron (entre 5-15 min, P = 0,003). Estos patrones fueron detectados para ambas asociaciones anestésicas. Por otra parte, la inducción anestésica y el tiempo de recuperación anestésica no fueron afectados por los tratamientos (P = 0,12 y P = 0,13 respectivamente). Los emúes tratados con tiletamina mostraron un mayor tiempo de anestesia quirúrgica, comparados con los emúes tratados con ketamina (P = 0,012). En el caso de A.S.T. y glucosa, ambas variables presentaron un incremento a las 24 h de la aplicación del tratamiento anestésico, resultando los niveles de glucosa más altos en emúes tratados con ketamina (P = 0,006 y P = 0,008 respectivamente). Finalmente, la hemoglobina, proteínas totales y ácido úrico no presentaron diferencias significativas entre tratamientos (P = 0,99, P = 0,97 y P= 0,81 respectivamente). En conclusión, los dos protocolos anestésicos resultaron seguros y eficientes para la manipulación de los animales; sin embargo, el mayor tiempo de anestesia observado en animales tratados con tiletamina podría determinar la preferencia por esta asociación anestésica.Summary: In this study, the effects of the anaesthetic associations atropine IM (0.05 mg/kg)-tiletamine/zolazepam IV (4 mg/kg total) and atropine IM (0.05 mg/kg)-ketamine IV (5 mg/kg total)/diazepam (0.5 mg/kg) on physiological, anaesthetic and biochemical responses were determined on adult emus. Animals (n = 7 per group) were randomly assigned to the two anaesthetic associations. Variables were measured at baseline, during surgical plane and during 30 min of observation. Heart rate and temperature increased at the beginning of the experimental period (between 5-10 min, P = 0.001), while respiratory frequency and pulse decreased (between 5-15 min, P = 0.003). These patterns were detected with both anaesthetic associations. Anaesthetic induction and recuperation time were not affected by treatments (P = 0.12 and P = 0.13 respectively). Emus treated with tiletamine showed a greater anaesthetic time than emus treated with ketamine (P = 0.012). Significant increases in A.S.T. and glucose were observed at 24 h post application of anaesthetic associations, resulting higher in ketamine emus (P = 0.006 and P = 0.008 respectively). Finally, there were no significant differences between anaesthetic treatments for haemoglobin, total proteins and uric acid (P = 0.99, P = 0.97 and P = 0.81 respectively). In conclusion, atropine-tiletamine/zolazepam and atropine- etamine/diazepam protocols resulted safe and efficient for animal manipulation, however the greater anaesthetic time observed in tiletamine-treated animals may determine preference for this anaesthetic combination

Role of the AT2 receptor in modulating the angiotensin II contractile response of the uterine artery at mid-gestation

Introduction: During human pregnancy, circulating concentrations of components of the renin—angiotensin system increase, but pressor refractoriness to angiotensin II (Ang-II) is observed. Given the importance of the Ang-II pressor response in deciding susceptibility to preeclampsia and of the Ang-II system for controlling uterine vasoreactivity, we sought to address the effects of pregnancy on the reactivity of the isolated uterine artery (UA) in mice. Materials and methods : Blood pressure was measured throughout pregnancy in awake C57BL/6J mice. UA segments were isolated from three groups of animals (non-pregnant, mid [day 12—13] and late [day 18—19] gestation) and studied by wire myography. Results: UA diameters, KCl-mediated responses, and acetylcholine-dependent vasorelaxation were greater at mid and late gestation than in non-pregnant animals. Ang-II responses were also greater during pregnancy, with an increased contraction in response to AT2 receptor blockade at mid-gestation. AT1 receptor blockade abolished the Ang-II response in all groups. Conclusions: Study findings are consistent with the possibility that AT2 receptor-mediated vasodilatation plays a role in modulating Ang-II contractile responses in pregnancy

Role of the AT2 receptor in modulating the angiotensin II contractile response of the uterine artery at mid-gestation

Introduction: During human pregnancy, circulating concentrations of components of the renin—angiotensin system increase, but pressor refractoriness to angiotensin II (Ang-II) is observed. Given the importance of the Ang-II pressor response in deciding susceptibility to preeclampsia and of the Ang-II system for controlling uterine vasoreactivity, we sought to address the effects of pregnancy on the reactivity of the isolated uterine artery (UA) in mice. Materials and methods : Blood pressure was measured throughout pregnancy in awake C57BL/6J mice. UA segments were isolated from three groups of animals (non-pregnant, mid [day 12—13] and late [day 18—19] gestation) and studied by wire myography. Results: UA diameters, KCl-mediated responses, and acetylcholine-dependent vasorelaxation were greater at mid and late gestation than in non-pregnant animals. Ang-II responses were also greater during pregnancy, with an increased contraction in response to AT2 receptor blockade at mid-gestation. AT1 receptor blockade abolished the Ang-II response in all groups. Conclusions: Study findings are consistent with the possibility that AT2 receptor-mediated vasodilatation plays a role in modulating Ang-II contractile responses in pregnancy

Acclimatization to chronic intermittent hypoxia in mine workers: a challenge to mountain medicine in Chile

In the past two decades, Chile has developed intense mining activity in the Andes mountain range, whose altitude is over 4,000 meters above sea level. It is estimated that a workforce population of over 55,000 is exposed to high altitude hypobaric hypoxia. The miners work under shift systems which vary from 4 to 20 days at the worksite followed by rest days at sea level, in a cycle repeated for several years. This Chronic Intermittent Hypoxia (CIH) constitutes an unusual condition for workers involving a series of changes at the physiological, cellular and molecular levels attempting to compensate for the decrease in the environmental partial pressure of oxygen (PO2). The mine worker must become acclimatized to CIH, and consequently undergoes an acute acclimatization process when he reaches the worksite and an acute reverse process when he reaches sea level. We have observed that after a period of 3 to 8 years of CIH exposure workers acclimatize well, and evidence from our studies and those of others indicates that CIH induces acute and chronic multisystem adjustments which are effective in offsetting the reduced availability of oxygen at high altitudes. The aims of this review are to summarize findings of the physiological responses to CIH exposure, highlighting outstanding issues in the field

Protection from inflammatory disease in insulin resistance: the role of mannan-binding lectin

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Listening In on the Past: What Can Otolith δ18O Values Really Tell Us about the Environmental History of Fishes?

Oxygen isotope ratios from fish otoliths are used to discriminate marine stocks and reconstruct past climate, assuming that variations in otolith δ18O values closely reflect differences in temperature history of fish when accounting for salinity induced variability in water δ18O. To investigate this, we exploited the environmental and migratory data gathered from a decade using archival tags to study the behaviour of adult plaice (Pleuronectes platessa L.) in the North Sea. Based on the tag-derived monthly distributions of the fish and corresponding temperature and salinity estimates modelled across three consecutive years, we first predicted annual otolith δ18O values for three geographically discrete offshore sub-stocks, using three alternative plausible scenarios for otolith growth. Comparison of predicted vs. measured annual δ18O values demonstrated >96% correct prediction of sub-stock membership, irrespective of the otolith growth scenario. Pronounced inter-stock differences in δ18O values, notably in summer, provide a robust marker for reconstructing broad-scale plaice distribution in the North Sea. However, although largely congruent, measured and predicted annual δ18O values of did not fully match. Small, but consistent, offsets were also observed between individual high-resolution otolith δ18O values measured during tag recording time and corresponding δ18O predictions using concomitant tag-recorded temperatures and location-specific salinity estimates. The nature of the shifts differed among sub-stocks, suggesting specific vital effects linked to variation in physiological response to temperature. Therefore, although otolith δ18O in free-ranging fish largely reflects environmental temperature and salinity, we counsel prudence when interpreting otolith δ18O data for stock discrimination or temperature reconstruction until the mechanisms underpinning otolith δ18O signature acquisition, and associated variation, are clarified

Valorization of By-Products from Biofuel Biorefineries: Extraction and Purification of Bioactive Molecules from Post-Fermentation Corn Oil

The aim of this work was to develop innovative and sustainable extraction, concentration, and purification technologies aimed to recover target substances from corn oil, obtained as side stream product of biomass refineries. Residues of bioactive compounds such as carotenoids, phytosterols, tocopherols, and polyphenols could be extracted from this matrix and applied as ingredients for food and feeds, nutraceuticals, pharmaceuticals, and cosmetic products. These molecules are well known for their antioxidant and antiradical capacity, besides other specific biological activities, generically involved in the prevention of chronic and degenerative diseases. The project involved the development of methods for the selective extraction of these minor components, using as suitable extraction technique solid phase extraction. All the extracted and purified fractions were evaluated by NMR spectroscopic analyses and UV–Vis spectrophotometric techniques and characterized by quali-quantitative HPLC analyses. TPC (total phenolic content) and TFC (total flavonoid content) were also determined. DPPH and ABTS radical were used to evaluate radical quenching abilities. Acetylcholinesterase (AChE), amylase, glucosidase, and tyrosinase were selected as enzymes in the enzyme inhibitory assays. The obtained results showed the presence of a complex group of interesting molecules with strong potential in market applications according to circular economy principles

Estructura y evolución tectónica del sector oriental del margen continental cantábrico: resultados de los perfiles de sísmica multicanal MARCONI

El Golfo de Vizcaya se formó durante el Cretácico como consecuencia de la apertura del Océano Atlántico. La convergencia entre las placas Euroasiática e Ibérica durante el Cenozoico dio lugar al levantamiento de la cordillera pirenaico-cantábrica y al cierre parcial del Golfo de Vizcaya. La mayor parte de esta deformación tiene lugar en el margen Noribérico, haciendo de este área un lugar único para estudiar los estadios iniciales de la deformación de un margen pasivo. En el verano de 2003, el experimento sísmico MARCONI permitió adquirir 11 perfiles de sísmica de reflexión vertical profunda utilizando el buque Hespérides, lo que ha proporcionado una nueva imagen 3D de la estructura cortical del sector SE del Golfo de Vizcaya. Los datos muestran que la estructura de este margen se caracteriza por una espesa secuencia de sedimentos meso-cenozoicos (hasta 4 s TWT, hasta > 6 km) parcialmente deformada por cabalgamiento y pliegues asociados, vergentes al N. Se han diferenciado tres conjuntos sedimentarios separados por discordancias que se corresponden con las secuencias alpinas pre-, sin- y postectónicas. Los datos sísmicos muestran también la existencia de cuencas mesozoicas con evidencias de inversión tectónica y la existencia de fallas y estructuras laterales coincidiendo con los importantes cañones submarinos de dirección aproximada N-S. Teniendo tambien en cuenta otros datos geofísicos, la estructura general del sector SE del Golfo de Vizcaya se ha interpretado como una corteza continental adelgazada o transicional deslizada hacia el S por debajo del extremadamente abrupto y muy deformado talud continental Noribérico