ABSTRACT
RATIONALE: Biased attention towards drug-related cues and reduced inhibitory control over the regulation of drug-intake characterize drug addiction. The noradrenaline system has been critically implicated in both attentional and response inhibitory processes and is directly affected by drugs such as cocaine. OBJECTIVES: We examined the potentially beneficial effects of the noradrenaline reuptake inhibitor atomoxetine in improving cognitive control during two tasks that used cocaine- and non-cocaine-related stimuli. METHODS: A double-blind, placebo-controlled, and cross-over psycho-pharmacological design was employed. A single oral dose of atomoxetine (40 mg) was administered to 28 cocaine-dependent individuals (CDIs) and 28 healthy controls. All participants performed a pictorial attentional bias task involving both cocaine- and non-cocaine-related pictures as well as a verbal go/no-go task composed of cocaine- and food-related words. RESULTS: As expected, CDIs showed attentional bias to cocaine-related cues whilst controls did not. More importantly, however, atomoxetine, relative to placebo, significantly attenuated attentional bias in CDIs (F 26 = 6.73, P = 0.01). During the go/no-go task, there was a treatment × trial × group interaction, although this finding only showed a trend towards statistical significance (F 26 = 3.38, P = 0.07). CONCLUSIONS: Our findings suggest that atomoxetine reduces attentional bias to drug-related cues in CDIs. This may result from atomoxetine's modulation of the balance between tonic/phasic activity in the locus coeruleus and the possibly parallel enhancement of noradrenergic neurotransmission within the prefrontal cortex. Studying how cognitive enhancers such as atomoxetine influence key neurocognitive indices in cocaine addiction may help to develop reliable biomarkers for patient stratification in future clinical trials.
Subject(s)
Adrenergic Uptake Inhibitors/administration & dosage , Atomoxetine Hydrochloride/administration & dosage , Attentional Bias/drug effects , Cocaine-Related Disorders/psychology , Cues , Administration, Oral , Adrenergic Uptake Inhibitors/blood , Adult , Atomoxetine Hydrochloride/blood , Attention/drug effects , Attention/physiology , Attentional Bias/physiology , Cocaine-Related Disorders/blood , Cocaine-Related Disorders/drug therapy , Cross-Over Studies , Double-Blind Method , Female , Humans , Male , Middle Aged , Photic Stimulation/methods , Psychomotor Performance/drug effects , Psychomotor Performance/physiology , Treatment OutcomeABSTRACT
Soil from a redundant coke oven site has been examined by extraction of soluble materials using 1-methyl-2-pyrrolidinone (NMP) followed by size exclusion chromatography (SEC) of the extracted material. The extracted material was found to closely resemble a high temperature coal tar pitch. Standard humic and fulvic acids were also examined since these materials are very soluble in NMP and would be extracted with pitch if present in the soil. Humic substances derived from peat samples and NMP-extracts of peats were also examined. The results show that the humic and fulvic substances were not extracted directly by NMP from peats. They were extracted using caustic soda solution and were different from the peat extracts in NMP. These results indicate that humic and fulvic acids were soluble in NMP in the protonated polyelectrolyte form but not in the original native polyelectrolyte form. The extraction of soil using NMP followed by SEC appears to be a promising method for identifying contamination by coal-based industries.
Subject(s)
Benzopyrans/analysis , Chromatography, Gel/methods , Coal Tar/analysis , Humic Substances/analysis , Soil Pollutants/analysis , Soil/analysis , Pyrrolidinones/chemistry , Solvents , Spectrometry, FluorescenceABSTRACT
The chaparral shrub Eriodictyon californicum secretes a phenolic leaf resin composed of flavonoid aglycones. We used leaves with artificially altered resin contents to test the effects of resin on the feeding, growth, and oviposition of the specialist herbivore Trirhabda diducta. In addition, we compared Trirhabda feeding and growth on young foliage with that on foliage from the preceding year. Our results show that the Eriodictyon leaf resin affects Trirhabda larvae and adults similarly, having no significant effect on growth rates or on nutrient utilization at up to 5X the resin levels normally encountered by larvae in the field. Both Trirhabda larvae and adults respond to high resin concentrations by increasing their consumption rates, with concomitant decreases in digestibility and the efficiency of conversion of ingested food to biomass. Low-resin foliage is preferred by larvae for feeding and by adults for oviposition. Larvae feeding on leaves of the current season have higher growth efficiencies, consumption, and growth compared to larvae feeding on leaves from the preceding year.
