Non-D9-tetrahydrocannabinol phytocannabinoids stimulate feeding in rats

Cannabinoid type 1 receptor-mediated appetite stimulation by D9tetrahydrocannabinol (D9THC) is well understood. Recently, it has become apparent that non-D9THC phytocannabinoids could also alter feeding patterns. Here, we show definitively that non-D9THC phytocannabinoids stimulate feeding. Twelve male, Lister-Hooded rats were prefed to satiety prior to administration of a standardized cannabis extract or to either of two mixtures of pure phytocannabinoids (extract analogues) comprising the phytocannabinoids present in the same proportions as the standardized extract (one with and one without D9THC). Hourly intake and meal pattern data were recorded and analysed using two-way analysis of variance followed by one-way analysis of variance and Bonferroni post-hoc tests. Administration of both extract analogues significantly increased feeding behaviours over the period of the test. All three agents increased hour-one intake and meal-one size and decreased the latency to feed, although the zero-D9THC extract analogue did so to a lesser degree than the high-D9THC analogue. Furthermore, only the analogue containing D9THC significantly increased meal duration. The data confirm that at least one non-D9THC phytocannabinoid induces feeding pattern changes in rats, although further trials using individual phytocannabinoids are required to fully understand the observed effects.

Cannabinol and cannabidiol exert opposing effects on rat feeding patterns

Rationale: Increased food consumption following Δ9- tetrahydrocannabinol-induced cannabinoid type 1 receptor agonism is well documented. However, possible non-Δ9- tetrahydrocannabinol phytocannabinoid-induced feeding effects have yet to be fully investigated. Therefore, we have assessed the effects of the individual phytocannabinoids, cannabigerol, cannabidiol and cannabinol, upon feeding behaviors. Methods: Adult male rats were treated (p.o.) with cannabigerol, cannabidiol, cannabinol or cannabinol plus the CB1R antagonist, SR141716A. Prior to treatment, rats were satiated and food intake recorded following drug administration. Data were analyzed for hourly intake and meal microstructure. Results: Cannabinol induced a CB1R-mediated increase in appetitive behaviors via significant reductions in the latency to feed and increases in consummatory behaviors via increases in meal 1 size and duration. Cannabinol also significantly increased the intake during hour 1 and total chow consumed during the test. Conversely, cannabidiol significantly reduced total chow consumption over the test period. Cannabigerol administration induced no changes to feeding behavior. Conclusion: This is the first time cannabinol has been shown to increase feeding. Therefore, cannabinol could, in the future, provide an alternative to the currently used and psychotropic Δ9-tetrahydrocannabinol-based medicines since cannabinol is currently considered to be non-psychotropic. Furthermore, cannabidiol reduced food intake in line with some existing reports, supporting the need for further mechanistic and behavioral work examining possible anti-obesity effects of cannabidiol.

Elevated atmospheric carbon dioxide impairs the performance of root-feeding vine weevils by modifying root growth and secondary metabolites

Predicting how insect crop pests will respond to global climate change is an important part of increasing crop production for future food security, and will increasingly rely on empirically based evidence. The effects of atmospheric composition, especially elevated carbon dioxide (eCO(2)), on insect herbivores have been well studied, but this research has focussed almost exclusively on aboveground insects. However, responses of root-feeding insects to eCO(2) are unlikely to mirror these trends because of fundamental differences between aboveground and belowground habitats. Moreover, changes in secondary metabolites and defensive responses to insect attack under eCO(2) conditions are largely unexplored for root herbivore interactions. This study investigated how eCO(2) (700 mu mol mol-1) affected a root-feeding herbivore via changes to plant growth and concentrations of carbon (C), nitrogen (N) and phenolics. This study used the root-feeding vine weevil, Otiorhynchus sulcatus and the perennial crop, Ribes nigrum. Weevil populations decreased by 33% and body mass decreased by 23% (from 7.2 to 5.4 mg) in eCO(2). Root biomass decreased by 16% in eCO(2), which was strongly correlated with weevil performance. While root N concentrations fell by 8%, there were no significant effects of eCO(2) on root C and N concentrations. Weevils caused a sink in plants, resulting in 8-12% decreases in leaf C concentration following herbivory. There was an interactive effect of CO(2) and root herbivory on root phenolic concentrations, whereby weevils induced an increase at ambient CO(2), suggestive of defensive response, but caused a decrease under eCO(2). Contrary to predictions, there was a positive relationship between root phenolics and weevil performance. We conclude that impaired root-growth underpinned the negative effects of eCO(2) on vine weevils and speculate that the plant's failure to mount a defensive response at eCO(2) may have intensified these negative effects.

Effect on components of the intestinal microflora and plasma neuropeptide levels of feeding Lactobacillus delbrueckii, Bifidobacterium lactis, and inulin to adult and elderly rats

The aim of this study was to compare the effects of the mixture of Lactobacillus delbrueckii subsp. rhamnosus strain GG, Bifidobacterium lactis Bb12, and inulin on intestinal populations of lactobacilli, bifidobacteria, and enterobacteria in adult and elderly rats fed the same (in quality and quantity) diet. The portal plasma levels of two neuropeptides, neuropeptide Y (NPY) and peptide YY (PYY), were also evaluated to assess the physiological consequences of the synbiotic treatment for the gastrointestinal (GI) tracts of rats of different ages. Adult (n = 24) and elderly (n = 24) male rats were fed the AIN-93 M maintenance diet. After 2 weeks of adaptation, the diet of 12 rats of each age group was supplemented with 8% inulin and with strains GG and Bb12 to provide 2.2 x 10(9) CFU of each strain g(-1) of the diet. Blood and different regions of the GI tract were sampled from all rats after 21 days of the treatment. Treatment with the mixture of strain GG, strain BB12, and inulin induced significantly different changes in the numbers of lactobacilli, bifidobacteria, and enterobacteria of the stomach, small intestine, cecum, and colon microflora. Moreover, the GG, BB12, and inulin mixture increased the concentrations of NPY and PYY for adult rats. For the elderly animals, the PYY concentration was not changed, while the NPY concentration was decreased by treatment with the GG, BB12, and inulin mixture. The results of the present study indicate that the physiological status of the GI tract, and not just diet, has a major role in the regulation of important groups of the GI bacteria community, since even the outcome of the dietary modification with synbiotics depends on the ages of the animals.

Investigation of the impact of feeding Lactobacillus plantarum CRL 1815 encapsulated in microbially derived polymers on the rat faecal microbiota

AIMS: The aim of this study was to evaluate the impact of the administration of microencapsulated Lactobacillus plantarum CRL 1815 with two combinations of microbially derived polysaccharides, xanthan : gellan gum (1%:0·75%) and jamilan : gellan gum (1%:1%), on the rat faecal microbiota. METHODS AND RESULTS: A 10-day feeding study was performed for each polymer combination in groups of 16 rats fed either with placebo capsules, free or encapsulated Lact. plantarum or water. The composition of the faecal microbiota was analysed by fluorescence in situ hybridization and temporal temperature gradient gel electrophoresis. Degradation of placebo capsules was detected, with increased levels of polysaccharide-degrading bacteria. Xanthan : gellan gum capsules were shown to reduce the Bifidobacterium population and increase the Clostridium histolyticum group levels, but not jamilan : gellan gum capsules. Only after administration of jamilan : gellan gum-probiotic capsules was detected a significant increase in Lactobacillus-Enterococcus group levels compared to controls (capsules and probiotic) as well as two bands were identified as Lact. plantarum in two profiles of ileum samples. CONCLUSIONS: Exopolysaccharides constitute an interesting approach for colon-targeted delivery of probiotics, where jamilan : gellan gum capsules present better biocompatibility and promising results as a probiotic carrier. SIGNIFICANCE AND IMPACT OF STUDY: This study introduces and highlights the importance of biological compatibility in the encapsulating material election, as they can modulate the gut microbiota by themselves, and the use of bacterial exopolysaccharides as a powerful source of new targeted-delivery coating material.

Optimal sting use in the feeding behavior of the scorpion Hadrurus spadix

Since venom is costly to produce and stinging is not obligatory in prey capture for scorpions, the need to optimize use of resources suggests that venom should be reserved for prey that cannot otherwise be overpowered, (i.e., larger and/or more active prey). In accordance with these predictions, sting use by Hadrurus spadix Stahnke 1940 increased with prey size, reaching 100% once prey items were longer than the scorpion’s pedipalp patella length, and with prey activity, which we manipulated by varying prey temperature. Surprisingly, the scorpions were slower to capture less active (cooler) prey than those that exhibited higher rates of activity. We suggest this is because prey are located by vibrations in the substrate, with less active prey producing fewer vibrations. Keywords: Optimal foraging, venom, pectines

Knowledge Interfaces and Practices of Negotiation: Cases from a Women's Group in Bolivia and an Oil Refinery in Wales

This chapter examines encounters between international institutions that frame their objectives through a global policy language, and people whose lives are the focus for change heralded by these institutions. It explores how a global policy language, which seeks consensus and equality, can be at odds with local understandings, conflict and intentions.

The causes of prescribing errors in English general practices: a qualitative study

Aim: To examine the causes of prescribing and monitoring errors in English general practices and provide recommendations for how they may be overcome. Design: Qualitative interview and focus group study with purposive sampling and thematic analysis informed by Reason’s accident causation model. Participants: General practice staff participated in a combination of semi-structured interviews (n=34) and six focus groups (n=46). Setting: Fifteen general practices across three primary care trusts in England. Results: We identified seven categories of high-level error-producing conditions: the prescriber, the patient, the team, the task, the working environment, the computer system, and the primary-secondary care interface. Each of these was further broken down to reveal various error-producing conditions. The prescriber’s therapeutic training, drug knowledge and experience, knowledge of the patient, perception of risk, and their physical and emotional health, were all identified as possible causes. The patient’s characteristics and the complexity of the individual clinical case were also found to have contributed to prescribing errors. The importance of feeling comfortable within the practice team was highlighted, as well as the safety of general practitioners (GPs) in signing prescriptions generated by nurses when they had not seen the patient for themselves. The working environment with its high workload, time pressures, and interruptions, and computer related issues associated with mis-selecting drugs from electronic pick-lists and overriding alerts, were all highlighted as possible causes of prescribing errors and often interconnected. Conclusion: This study has highlighted the complex underlying causes of prescribing and monitoring errors in general practices, several of which are amenable to intervention.

Pesticide-handling practices of smallholder coffee farmers in Eastern Jamaica

Pesticide use among smallholder coffee producers in Jamaica has been associated with significant occupational health effects. Research on pesticide handling practices, however, has been scarce, especially in eastern Jamaica. This explorative study aims at filling this gap and provides a first basis to develop effective interventions to promote a safer pesticide use. A random sample of 81 coffee farmers was surveyed. The majority of farmers reported to suffer from at least one health symptom associated with pesticide handling, but safety practices were scarcely adopted. There was also the risk that other household members and the wider local community are exposed to pesticides. The lack of training on pesticide management, the role of health services and the cost for protective equipment seemed to be the most significant factors that influence current pesticide handling practices in eastern Jamaica. Further research is recommended to develop a systemic understanding of farmer’s behaviour to provide a more solid basis for the development of future intervention programmes.

Educational reforms, cultural clashes and classroom practices

This article presents an ongoing study of educational policy enactment in Singapore lower primary English classrooms. It explores how teachers react to and interpret educational reforms in their classroom practices against a backdrop ofvtraditional cultural values. Using a prescribed coding scheme, the article presents the instructional organisational patterns and participation structures of the lessons.Through a systematic analysis of the enacted curricula, the paper examines classroom practices as well as teaching and learning activities in Primary 1 (7–8 years) and Primary 2 (8–9 years) English lessons in Singapore. The results suggest that there are cultural clashes between major educational reforms which emphasise independent/critical thinking and ‘Asian values’ which promote respect for authority and conformity.