Influence of some 1,3,5-triazine herbicides on peroxidase activity in corn seedlings

The effect of some 1,3,5-triazine herbicides, on the rate of oxidative decarboxylation of tryptophan by peroxidase from corn seedlings, varied with the concentration. Atrazine was stimulatory in vivo at 10-⁶M but not at 10⁸ M or lower, whereas terbutryne was inhibitory at 10-⁶M but not at 10-⁸M or below. Prometryne inhibited enzyme activity at 10-⁶M and stimulated it at 10-¹⁰M and at 10¹²M, while simazine caused stimulation at 10-⁶M and inhibition at 10^?10M and 10^?12M. Atraton reduced enzyme activity at 10^?6M and 10^?8M but had no effect at 10^?10M and 10^?12M. When peroxidase activity was assayed in acetone-dried powders from seeds, harvested from fields that had received typical atrazine applications, the quantities of tryptophan consumed were significantly less than the quantity determined in the control powder. From the results obtained, by incorporating dealkylated and 2-hydroxy metabolites of atrazine at 10^?6M into the culture solutions, it seems possible that the inhibition observed may have been due to the presence of 4-amino-6-ethylamino-1, 3, 5-triazin-2-ol and/or 4, 6-diamino-1, 3, 5-triazin-2-ol residues in seeds from treated plots, even if, in previously reported experiments, analyses had not detected their presence.     

Genetic analysis and molecular characterisation of laboratory and field mutants of Botryotinia fuckeliana (Botrytis cinerea) resistant to QoI fungicides

BACKGROUND: QoI fungicides, inhibitors of mitochondrial respiration, are considered to be at high risk of resistance development. In several phytopathogenic fungi, resistance is caused by mutations (most frequently G143A) in the mitochondrial cytochrome b (cytb) gene. The genetic and molecular basis of QoI resistance were investigated in laboratory and field mutants of Botryotinia fuckeliana (de Bary) Whetz. exhibiting in vitro reduced sensitivity to trifloxystrobin. RESULTS: B. fuckeliana mutants highly resistant to trifloxystrobin were obtained in the laboratory by spontaneous mutations in wild‐type strains, or from naturally infected plants on a medium amended with 1–3 mg L^?1 trifloxystrobin and 2 mM salicylhydroxamic acid, an inhibitor of alternative oxidase. No point mutations were detected, either in the complete nucleotide sequences of the cytb gene or in those of the aox and Rieske protein genes of laboratory mutants, whereas all field mutants carried the G143A mutation in the mitochondrial cytb gene. QoI resistance was always maternally inherited in ascospore progeny of sexual crosses of field mutants with sensitive reference strains. CONCLUSIONS: The G143A mutation in cytb gene is confirmed to be responsible for field resistance to QoIs in B. fuckeliana. Maternal inheritance of resistance to QoIs in progeny of sexual crosses confirmed that it is caused by extranuclear genetic determinants. In laboratory mutants the heteroplasmic state of mutated mitochondria could likely hamper the G143A detection, otherwise other gene(s) underlying different mechanisms of resistance could be involved. Copyright © 2012 Society of Chemical Industry     

Effect of extradurally administered morphine on postoperative analgesia in dogs undergoing surgery for thoracolumbar intervertebral disk extrusion

Objective-To investigate the effect of intraoperative extradural morphine administration on postoperative analgesia in dogs undergoing thoracolumbar spinal surgery to treat disk extrusion. Design-Prospective clinical trial. Animals-26 client-owned dogs undergoing thoracolumbar spinal surgery. Procedures-Animals were randomly allocated to receive morphine (0.1 mg/kg [0.045 mg/lb], extradurally) or no treatment (control group). Following preanesthetic medication with methadone (0.25 mg/kg [0.11 mg/lb], IM), anesthesia was induced with propofol and maintained with isoflurane or sevoflurane in oxygen. Lidocaine and fentanyl were administered during surgery in both groups at fixed rates. In the morphine administration group, morphine was splashed over the dura mater immediately prior to wound closure. Postoperative analgesia was assessed for 48 hours by assessors unaware of group allocation, and methadone was administered as rescue analgesic. Demographic characteristics, urinary output, days of hospitalization, and perioperative use of analgesics were compared via a Mann-Whitney U test. Results-Demographic data were similar between groups. In the morphine administration group, 2 of 13 dogs required postoperative methadone, and in the control group, methadone was administered to 11 of 13 dogs. The total number of doses of methadone administered in the 48 hours after surgery was 28 in the control group and 3 in the morphine administration group. No adverse effects were recorded in any group. Conclusions and Clinical Relevance-Intraoperative extradural morphine administration was effective in reducing postoperative analgesic requirement. Dogs undergoing thoracolumbar spinal surgery benefited from topical administration of preservative-free morphine administered directly on the dura mater as part of analgesic management.     

A relevant long-term impact of the circulation of a potentially contaminated vaccine on the distribution of scrapie in Italy. Results from a retrospective cohort study

ABSTRACT: A sudden increase in the incidence of scrapie in Italy in 1997 was subsequently linked to theuse of a potentially infected vaccine against contagious agalactia. The relative risk for theexposed farms ranged between 6 and 40. The aim of this study was to assess the long-termimpact of exposure to the potentially scrapie-contaminated vaccine on the Italian classicalscrapie epidemic. We carried out a retrospective cohort study, fitting mixed-effects Poissonregression models, dividing national geographic areas into exposure categories on the basis ofthe vaccine circulation levels. We took into account the sensitivity of the surveillance systemapplied in the different areas. The population attributable fraction (PAF) was used to assessthe impact on the total population of farms associated with the effect of circulation of thevaccine. The provinces where the vaccine was more often sold were noted to have a higherlevel of disease when compared to those provinces where the vaccine was sold less often(incidence rate ratio [IRR]: 2.7; 95% confidence interval [CI]: 1.1-6.5). The populationattributable fraction was high (68.4%). Standardization techniques allowed to account for thepotential of geographical variability in the sensitivity of the Italian surveillance system.Although the number of the directly exposed farms was limited, an important long-termimpact of the vaccine circulation could be quantified in terms of secondary outbreaks likelydue to the exchange of animals from directly exposed flocks.     

Microsatellite analyses for evaluation of genetic diversity among Sicilian grapevine cultivars

A total of 82 grapevine genotypes were sampled from several areas of the Italian region of Sicily where vineyards are widely spread. The grapevines were characterized using six microsatellite markers (VVS2, VVMD5, VVMD7, VVMD27, VrZAG62 and VrZAG79) to evaluate genetic diversity. Thirty-seven of the 82 cultivars sampled had their names quoted in historical and literary sources, while 45 cultivars from old vineyards did not have their names reported in ancient literature. According to their genetic profiles at SSR loci, 70 different cultivars were found, while interesting cases of synonymies (Regina and Moscato bianco, Alicante and Dolcetta or among different clones of Zibibbo and Catarratto) and cases of homonymy (Frappato and Nerello Mascalese) were discovered. Several genetic parameters were calculated to assess the efficacy of the loci chosen in this work. Pairwise genetic distances between all cultivars were calculated. A dendrogram representing the genetic similarities among cultivars was depicted using the UPGMA method to investigate their relationships, explaining them from a historical point of view. The cluster distribution of cultivars clearly does not reflect their current geographical distribution, suggesting successive introductions of cultivars in Sicily from different areas of origin.     

Influence of time of food administration on daily rhythm of total locomotor activity in ponies

The activity rhythm can be entrained by nonphotic cues, especially food availability. Daily feeding schedules can act as “Zeitgeber” to synchronize the circadian system. In this study, the authors evaluated the influence of different feeding schedules on the daily rhythm of total locomotor activity in ponies. Six clinically healthy Shetland ponies were kept under natural 12/12-h light/dark cycle and monitored during 4 different feeding schedules: fed twice (at 8 am and 8 pm), fasted, fed at 8 pm, fed at 8 am, and fed twice a day again. Water was available ad libitum. To record total activity, we equipped the animals with actigraphy-based data loggers (Actiwatch-Mini). Two-way analysis of variance revealed a significant main effect of the time of day and no effect of feeding schedules on the amount of total locomotor activity. Locomotor activity showed daily rhythmicity in all experimental conditions, with diurnal acrophase. The amplitude of the rhythms and their robustness statistically changed across all experimental conditions. Our findings support the theory that when given essentially free choice hay, the time of feeding did not entrain activity, and suggest that feeding behavior can influence the distribution of locomotor activity during a 24-hour period in ponies, with changes in the amplitude and robustness of the rhythm.     

Cortisol response to road transport stress in calm and nervous stallions

Cortisol may be useful as a marker in predicting how an animal will respond to stressful stimuli, thus providing information on animal's temperament. To quantify the level of transport stress and the effect of temperament on the adrenocortical response, the change in circulating cortisol levels was evaluated in 84 healthy experienced thoroughbred and crossbred stallions, mean age 11.4 ± 4.5 years old, after road transport in a commercial trailer (6 horses per load, stocking density: 2 m²/horse), over mean distances of 210 ± 11.8 km for about 3 hours. Several experienced caretakers were asked to complete 2 questionnaires, one that used a 5-point scale to subjectively evaluate temperament and another that used a 3-point scale to assess tendencies in response to ordinary care and daily management. The scores for the latter were defined as follows: a score of 1 indicated that the horse had never or rarely troubled the caretaker during management, 2 occasionally, and 3 usually. On this basis, the subjects were distinguished between calm and nervous stallions. Blood samples were taken same daytime (8.00 am), in single box, immediately before loading, then after transport and unloading. Serum cortisol concentrations were analyzed in duplicate by immunoenzymatic assay. Compared with basal levels, cortisol increases were observed in both calm (P < 0.001) and nervous (P < 0.05) stallions after transport. Repeated-measures analysis of variance showed significant effects of transport on cortisol changes (P < 0.001). Nervous subjects showed lower (P < 0.01) cortisol levels than did calm subjects after transport, and basal cortisol levels did not differ between calm and nervous subjects. No significant differences (P > 0.05) between different age, breed, and orientation were detected.The results showed that temperament could influence the adrenocortical responses of stallions after short-term transportation. The presence of the same staff for handling, loading, confinement, and unloading, the same veterinarian taking all blood samples, and the presence of cospecifics did not reduce the response to short transport stress both in calm and nervous stallions already accustomed to transport. Lower cortisol concentrations in nervous subjects might be because of failure of the adrenal cortex to respond normally to transport stress. Moreover, signs of transport stress were less pronounced in nervous stallions.