Blood gas and acid-base status during tiletamine/zolazepam anaesthesia in dogs

OBJECTIVE: To evaluate the effect of the tiletamine/zolazepam (TZ) combination (Zoletil 100; Virbac, Carros, France) with and without atropine on blood gas values and acid-base status in dogs. STUDY DESIGN: Randomized cross-over experimental study. ANIMALS: Six healthy adult cross-bred dogs, weighing 11.0-18.5 kg. MATERIALS AND METHODS: Each dog received four different drug treatments at intervals of at least 15 days: (i) 5 mg kg(-1) intravenous (IV) TZ (TZ.IV); (ii) 10 mg kg(-1) intramuscular (IM) TZ (TZ.IM); (iii) atropine, 20 microg kg(-1) IV, followed 5 minutes later by 5 mg kg(-1) TZ IV (A.TZ.IV); and (IV) atropine (same dose) given 5 minutes before 10 mg kg(-1) TZ IM (A.TZ.IM). Arterial blood samples were collected from each dog before drug administration (baseline) at induction of anaesthesia (time 0) and 2, 5, 10 and 30 minutes thereafter. RESULTS: Transient hypoxaemia and respiratory acidosis were observed just after induction. PaO(2) and SaO(2) dropped, while H(+) concentration and PaCO(2) rose significantly above baseline values. In groups TZ.IV and A.TZ.IV, PaO(2) values as low as 6.0-6.4 kPa (45-48 mm Hg) were recorded. However, there was no significant difference in blood gas variables among the groups encountered during the evaluation period. The overall change in [HCO(3) (-)] and base excess (BE) was not significant among groups. Atropine did not affect the above variables. CONCLUSIONS AND CLINICAL RELEVANCE: Tiletamine/zolazepam injection may induce transient hypoxaemia and respiratory acidosis, but acid-base status changes are clinically unimportant. Particularly, close observation of dogs is recommended during the first 5-10 minutes after induction with TZ, especially in animals with cardiopulmonary disease. TZ should perhaps not be used in animals intolerant of tachycardia.     

A comparison of propofol, thiopental or ketamine as induction agents in goats

OBJECTIVE: To compare propofol, thiopental and ketamine as induction agents before halothane anaesthesia in goats. STUDY DESIGN: Prospective, randomized cross-over study. Animals Seven healthy adult female goats with mean (+/-SD; range) body mass of 38.9 +/- 3.29 kg; 35-45 kg. METHODS: The seven animals were used on 21 occasions. Each received all three anaesthetics in a randomized cross-over design, with an interval of at least 2 weeks before re-use. Anaesthesia was induced with intravenous (IV) propofol (3 mg kg(-1)), thiopental (8 mg kg(-1), IV) or ketamine (10 mg kg(-1), IV). Following tracheal intubation, anaesthesia was maintained with halothane for 30 minutes. Indirect blood pressure, heart rate, respiratory rate and arterial blood gases were monitored. The quality of induction and recovery, recovery times and incidence of side-effects were recorded. RESULTS: Induction of anaesthesia was smooth and uneventful, and tracheal intubation was easily performed in all but two goats receiving ketamine. Changes in cardiopulmonary variables and acid-base status were similar with all three induction agents and were within clinically acceptable limits. Mean recovery times (time to recovery of swallowing reflex and to standing) were significantly shorter, and side-effects, e.g. apnoea, regurgitation, hypersalivation and tympany, were less common in goats receiving propofol, compared with the other treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Propofol 3 mg kg(-1) IV is superior to thiopental and ketamine as an induction agent before halothane anaesthesia in goats. It provides uneventful recovery which is more rapid than thiopental or ketamine, so reduces anaesthetic risk.     

ORFA: introducing a method for maximizing social profit from soil remediation funds

Purpose  

Contaminated land is a major problem. The remediation cost of brownfields in Europe and the USA exceeds 550 billion €; however, rehabilitation is on a slow pace. It is estimated that the money spent so far correspond to just 5% of the required one to eliminate the problem. The high cost of remediation, along with the inefficiency of the available funds, gives rise to a need for a method to effectively allocate remediation funds.     

Accurate and reproducible determination of lignin molar mass by acetobromination

The accurate and reproducible determination of lignin molar mass by using size exclusion chromatography (SEC) is challenging. The lignin association effects, known to dominate underivatized lignins, have been thoroughly addressed by reaction with acetyl bromide in an excess of glacial acetic acid. The combination of a concerted acetylation with the introduction of bromine within the lignin alkyl side chains is thought to be responsible for the observed excellent solubilization characteristics acetobromination imparts to a variety of lignin samples. The proposed methodology was compared and contrasted to traditional lignin derivatization methods. In addition, side reactions that could possibly be induced under the acetobromination conditions were explored with native softwood (milled wood lignin, MWL) and technical (kraft) lignin. These efforts lend support toward the use of room temperature acetobromination being a facile, effective, and universal lignin derivatization medium proposed to be employed prior to SEC measurements.     

Changes in nutrient allocation between roots and shoots of young maize plants during sulfate deprivation

Hydroponically grown maize (Zea mays L.) plants were deprived of the external source of sulfate following an initial period of 13 d during which the sulfur (S) supply was sufficient. The amounts of dry mass (DM), water, sulfate, sulfur, nitrate, ammonium, nitrogen, phosphorus, potassium, magnesium, calcium, boron, iron, copper, zinc, and manganese were monitored in the shoots and the roots for 10 d. The deprivation altered the nutritional balance between them, causing a 70% decrease of sulfate in shoots and roots after 2 d. At 10 d, 95% of sulfate had vanished in both shoots and roots. Total S remained rather constant in shoots or was slightly decreased in roots after 4 d. This coincided with a decrease of Fe in shoots after 4 d. The calculated decreases of S and Fe in –S shoots, up to 6 d were linearly correlated. Kinetic analysis of the changes revealed a sequence in their onset, and we distinguished early and late changes. Among the early changes, we highlight the following ones: (1) an increased amount of Cu in both shoots and roots at 2 d; Fe was 40% decreased in both shoots and roots at 2 d; (2) a decrease in transpiration rate by 35% after 2 d; (3) alterations in boron allocation; in –S shoots the % changes in S were linearly correlated with the corresponding % changes in B; (4) calcium content was not affected by the S deprivation in –S shoots, whilst it increased in –S root after d 2; (5) Mn and Mg decreased from the beginning and in a uniform fashion in both –S shoots and roots. Day 6 may be considered as the boundary between the early and late changes. The root fraction of DM increased progressively after 4 d. Changes in DM seemed to be similar to those of P. Changes of Zn also took place rather late. In –S shoots and for the time interval between 6 d and 10 d, linear correlations were found between the corresponding % changes of the pairs DM–S, DM–P, DM–N, DM–water, S–N, S–P, and N–P.     

Observations on the increase of wild gilthead seabream,Sparus aurata abundance,in the eastern Adriatic Sea: problems and opportunities

The recent increase of the local population of gilthead seabream, Sparus aurata, in three areas along the southeastern Adriatic Sea: Malostonski Bay (Croatia and Bosnia and Herzegovina), Neretva Estuary (Croatia) and Boka Kotorska Bay (Montenegro) and its adverse effects on shellfish culture by preying on Mediterranean mussels, Mytilus galloprovincialis, and the European flat oyster, Ostrea edulis, are studied. The results from the analysis of the existing information show that the main reason for the recent increase is the escapes from local fish farm which enrich the local population constantly with new gilthead sea bream. The existence of practically endless food in the area of the shellfish farms allows the concentration of the population in the region instead of its dispersion along the Adriatic coast. Moreover, ecological analysis indicates that the gilthead seabream is facing a very low competition from other local species which enhances its capacity to further populate the region. While the impact on the ecosystem is not yet known, the socio-economic impact of the increase of the gilthead seabream population is evident today. Many shellfish farms are closing today in the region since the damages may reach over 90 % of the production.     

Storage of olives (Olea europaea L.) under CO2 atmosphere: liquid chromatography-mass spectrometry characterization of indices related to changes in polyphenolic metabolism

Olives (Olea europaea cv. Chondrolia) were stored under a CO2 atmosphere immediately after harvesting for a period of 12 days. Samples obtained at 24-h intervals were analyzed by HPLC to identify components that may reflect changes in the biochemical behavior of the tissue. Four substances were shown to undergo significant fluctuations during storage, while their evolution was found to be different in olives stored under CO2 from those stored under regular atmospheric conditions (control). On the basis of data provided by liquid chromatography-electrospray ionization mass spectrometry, these substances were tentatively identified as hydroxytyrosol glucoside, demethylated ligstroside aglycone, ibotalactone A methyl ester, and verbascoside. The data are discussed in relation to the effect of postharvest treatments of olives for purposes of manipulating their polyphenolic content and plausible development of novel debittering processes.     

Predicting mean aboveground forest biomass and its associated variance

An approach to simplify the prediction of average aboveground forest biomass values and their associated variability is presented in this study. The advantage of the proposed approach is based on the fact that it can be applied to any form of equation describing tree size–shape relationships and to any tree species. The proposed approach was tested against a tree-level dataset comprising of 1211 pairs of aboveground tree biomass (M) and tree diameter (D) values. The compiled trees were grouped into several D classes and average M estimates (μ_M) with their associated variances (σ_M) were predicted for each class based on second-order Taylor expansion formulas. Nineteen beech (Fagus moesiaca Cz.) plots were also used to derive μ_M and σ_M estimates on an area basis in order to test the applicability of the approach on forest scale. The only assumption made was that the simple allometric model M = aD^b can accurately describe the M–D relationship. The results indicated that the mere recording of D distribution and appropriate selection of a and b values may provide very good estimates for μ_M and σ_M both at global and forest level. It is therefore concluded that biomass studies related to carbon sequestration, biofuel potential, ecophysiological processes and management practices are considerably simplified.