Polyunsaturated fatty acids in tumour-induced cachexia

A transplantable murine colon adenocarcinoma (MAC16) was utilised as a model of human cancer cachexia. This tumour has been found to produce extensive weight loss, characterised by depletion of host body protein and lipid stores at a small tumour burden. This weight loss has been found to be associated with production by the tumour of a lipolytic factor, activity of which was inhibited in vitro by the polyunsaturated fatty acid (PUFA) eicosapentaenoic acid (EPA). EPA has also been shown to possess anti-tumour and anti-cachectic activity in vivo, leading to the hypothesis that fatty acids mobilised by the lipolytic factor supply a growth requirement of the MAC16 tumour. In this study mobilisation and sequestration of fatty acids by the tumour was found to be non-specific, although a relationship between weight loss and arachidonic acid (AA) concentration was found in both tumour-bearing mice, and human cancer patients. The anti-tumour effect of EPA, which was found to be associated with an increase in cell loss, but not its anti-cachectic activity, was reversed by the administration of the PUFAs oleic acid (OA) and linoleic acid (LA). LA was also found to be capable of stimulating tumour growth. Inhibition of either the cyclooxygenase or lipoxygenase pathways was found to result in reduction of tumour growth, leading to the implication of one of the metabolites of LA or AA in tumour growth and cachexia. The ethyl ester of EPA was found to be inactive against the growth and cachexia of the MAC16 tumour, due to its retarded uptake compared with the free acid. The anti-proliferative agent 5-fluorouracil was found to cause tumour growth inhibition, and when given in combination with EPA, reduced the phase of tumour regrowth observed after 4 to 5 days of treatment with EPA.

Role of β-adrenergic receptors in the anti-obesity and anti-diabetic effects of zinc-α2-glycoprotien (ZAG)

Objectives: The goal of the current study is to determine whether the ß-adrenoreceptor (ß-AR) plays a role in the anti-obesity and anti-diabetic effects of zinc-a2-glycoprotein (ZAG). Material and methods: This has been investigated in CHO-K1 cells transfected with the human ß1-, ß2-, ß3-AR and in ob/ob mice. Cyclic AMP assays were carried out along with binding studies. Ob/ob mice were treated with ZAG and glucose transportation and insulin were examined in the presence or absence of propranolol. Results: ZAG bound to the ß3-AR with higher affinity (Kd 46±1nM) than the ß2-AR (Kd 71±3nM) while there was no binding to the ß1-AR, and this correlated with the increases in cyclic AMP in CHO-K1 cells transfected with the various ß-AR and treated with ZAG. Treatment of ob/ob mice with ZAG increased protein expression of ß3-AR in gastrocnemius muscle, and in white and brown adipose tissues, but had no effect on expression of ß1- and ß2-AR. A reduction of body weight was seen and urinary glucose excretion, increase in body temperature, reduction in maximal plasma glucose and insulin levels in the oral glucose tolerance test, and stimulation of glucose transport into skeletal muscle and adipose tissue, were completely attenuated by the non-specific ß-AR antagonist propranolol. Conclusion: The results suggest that the effects of ZAG on body weight and insulin sensitivity in ob/ob mice are manifested through a ß-3AR, or possibly a ß2-AR.

Type 2 diabetes and dog walking:patients' longitudinal perspectives about implementing and sustaining physical activity

Background - Physical activity is particularly important for people with type 2 diabetes, as evidence suggests that any reduction in sedentary time is good for metabolic health. Aim - To explore type 2 diabetes patients' talk about implementing and sustaining physical activity. Design of study - Longitudinal, qualitative study using repeat in-depth interviews with 20 patients over 4 years following clinical diagnosis. Setting - Patients were recruited from 16 general practices and three hospitals across Lothian, Scotland. Results - Discussion, and salience, of physical activity was marginal in patient accounts of their diabetes management. Patients claimed to have only received vague and non-specific guidance about physical activity from health professionals, and emphasised a perceived lack of interest and encouragement. Aside from walking, physical activities which were adopted tended to attenuate over time. Patients' accounts revealed how walking a dog assisted this kind of activity maintenance over time. Three main themes are highlighted in the analysis: 1) incidental walking; 2) incremental physical activity gains; and 3) augmenting physical activity maintenance. The problems arising from walking without a dog (for example, lack of motivation) are also examined. Conclusion - Asking patients about pet preferences might seem tangential to medical interactions. However, encouraging dog walking or identifying another interest that promotes a regular commitment to undertake physical activity may yield long-term health benefits.

Functional CB2 type cannabinoid receptors at CNS synapses

To date, it has been thought that cannabinoid receptors in CNS are primarily of the CB1R subtype, with CB2R expressed only in glia and peripheral tissues. However, evidence for the expression of CB2 type cannabinoid receptors at neuronal sites in the CNS is building through anatomical localization of receptors and mRNA in neurons and behavioural studies of central effects of CB2R agonists. In the medial entorhinal area of the rat, we found that blockade of CB1R did not occlude suppression of GABAergic inhibition by the non-specific endogenous cannabinoid 2-AG, suggesting that CB1R could not account fully for the effects of 2-AG. Suppression could be mimicked using the CB2R agonist JWH-133 and reversed by the CB2R inverse agonist AM-630, indicating the presence of functional CB2R. When we reversed the order of drug application AM-630 blocked the effects of the CB2R agonist JWH-133, but not the CB1R inverse agonist LY320135. JTE-907, a CB2R inverse agonist structurally unrelated to AM-630 elicited increased GABAergic neurotransmission at picomolar concentrations. Analysis of mIPSCs revealed that CB2R effects were restricted to action potential dependent, but not action potential independent GABA release. These data provide pharmacological evidence for functional CB2R at CNS synapses.

Increased salience of gains versus decreased associative learning differentiate bipolar disorder from schizophrenia during incentive decision making

Background Abnormalities in incentive decision making, typically assessed using the Iowa Gambling Task (IGT), have been reported in both schizophrenia (SZ) and bipolar disorder (BD). We applied the Expectancy-Valence (E-V) model to determine whether motivational, cognitive and response selection component processes of IGT performance are differentially affected in SZ and BD. Method Performance on the IGT was assessed in 280 individuals comprising 70 remitted patients with SZ, 70 remitted patients with BD and 140 age-, sex-and IQ-matched healthy individuals. Based on the E-V model, we extracted three parameters, 'attention to gains or loses', 'expectancy learning' and 'response consistency', that respectively reflect motivational, cognitive and response selection influences on IGT performance. Results Both patient groups underperformed in the IGT compared to healthy individuals. However, the source of these deficits was diagnosis specific. Associative learning underlying the representation of expectancies was disrupted in SZ whereas BD was associated with increased incentive salience of gains. These findings were not attributable to non-specific effects of sex, IQ, psychopathology or medication. Conclusions Our results point to dissociable processes underlying abnormal incentive decision making in BD and SZ that could potentially be mapped to different neural circuits. © 2012 Cambridge University Press.

Pre-attentive auditory sensory processing in autistic spectrum disorder:are electromagnetic measurements telling us a coherent story?

Sensory processing is a crucial underpinning of the development of social cognition, a function which is compromised in variable degree in patients with pervasive developmental disorders (PDD). In this manuscript, we review some of the most recent and relevant contributions, which have looked at auditory sensory processing derangement in PDD. The variability in the clinical characteristics of the samples studied so far, in terms of severity of the associated cognitive deficits and associated limited compliance, underlying aetiology and demographic features makes a univocal interpretation arduous. We hypothesise that, in patients with severe mental deficits, the presence of impaired auditory sensory memory as expressed by the mismatch negativity could be a non-specific indicator of more diffuse cortical deficits rather than causally related to the clinical symptomatology. More consistent findings seem to emerge from studies on less severely impaired patients, in whom increased pitch perception has been interpreted as an indicator of increased local processing, probably as compensatory mechanism for the lack of global processing (central coherence). This latter hypothesis seems extremely attractive and future trials in larger cohorts of patients, possibly standardising the characteristics of the stimuli are a much-needed development. Finally, specificity of the role of the auditory derangement as opposed to other sensory channels needs to be assessed more systematically using multimodal stimuli in the same patient group. (c) 2006 Elsevier B.V. All rights reserved.

5-Hydroxytryptamine induced excitation and inhibition in the subthalamic nucleus:action at 5-HT2C, 5-HT4 and 5-HT1A receptors

Extracellular single-unit recordings in mouse brain slices were used to determine the effect of exogenously applied 5-HT on STN neurones. Recordings were made from 74 STN cells which fired action potentials at a regular rate of 7.19 ± 0.5 Hz. In 61 cells (82%), 5-HT application increased STN neurone firing rate (10 μM, 180 ± 16.8%, n = 35) with an estimated EC 50 of 5.4 μM. The non-specific 5-HT2 receptor agonist α-methyl 5-HT (1-10 μM) mimicked 5-HT induced excitations (15 cells). These excitations were significantly reduced by pre-perfusion with the specific 5-HT2C receptor antagonist RS102221 (500 nM, 9 cells) and the 5HT4 antagonist GR113808 (500 nM, 7 cells). In 6 cells (8%) 5-HT induced biphasic responses where excitation was followed by inhibition, while in 7 cells (9%) inhibition of firing rate was observed alone. Inhibitory responses were reduced by the 5-HT1A antagonist WAY100135 (1 μM, 4 cells). No inhibitory responses were observed following α-methyl 5-HT applications. Both the excitations and inhibitions were unaffected by picrotoxin (50 μM, n = 5) and CNQX (10 μM, n = 5) indicative of direct postsynaptic effects. Thus, in STN neurones, 5-HT elicits two distinct effects, at times on the same neurone, the first being an excitation which is mediated by 5-HT 2C and 5-HT4 receptors and the second an inhibition which is mediated by 5-HT1A receptors. © 2005 Elsevier Ltd. All rights reserved.

Can surface energy measurements predict the impact of catalyst hydrophobicity upon fatty acid esterification over sulfonic acid functionalised periodic mesoporous organosilicas?

Sulfonic acid functionalised periodic mesoporous organosilicas (PrSO3 H-PMOs) with tunable hydrophobicity were synthesised via a surfactant-templating route, and characterised by porosimetry, TEM, XRD, XPS, inverse gas chromatography (IGC) and ammonia pulse chemisorption. IGC reveals that incorporation of ethyl or benzyl moieties into a mesoporous SBA-15 silica framework significantly increases the non-specific dispersive surface energy of adsorption for alkane adsorption, while decreasing the free energy of adsorption of methanol, reflecting increased surface hydrophobicity. The non-specific dispersive surface energy of adsorption of PMO-SO3H materials is strongly correlated with their activity towards palmitic acid esterification with methanol, demonstrating the power of IGC as an analytical tool for identifying promising solid acid catalysts for the esterification of free fatty acids. A new parameter [-ΔGCNP-P], defined as the per carbon difference in Gibbs free energy of adsorption between alkane and polar probe molecules, provides a simple predictor of surface hydrophobicity and corresponding catalyst activity in fatty acid esterification. © 2014 Elsevier B.V.

Functional neuroanatomy and behavioural correlates of the basal ganglia:evidence from lesion studies

Introduction: The basal ganglia are interconnected with cortical areas involved in behavioural, cognitive and emotional processes, in addition to movement regulation. Little is known about which of these functions are associated with individual basal ganglia substructures. Methods: Pubmed was searched for literature related to behavioural, cognitive and emotional symptoms associated with focal lesions to basal ganglia structures in humans. Results: Six case-control studies and two case reports were identified as relevant. Lesion sites included the caudate nucleus, putamen and globus pallidus. These were associated with a spectrum of behavioural and cognitive symptoms, including abulia, poor working memory and deficits in emotional recognition. Discussion: It is often difficult to precisely map associations between cognitive, emotional or behavioural functions and particular basal ganglia substructures, due to the non-specific nature of the lesions. However, evidence from lesion studies shows that most symptoms correspond with established non-motor frontal-subcortical circuits. © 2013-IOS Press and the authors. All rights reserved.

Investigating ocular allergy:can we determine a better measurement?

Objective: Ocular allergy is a broad group of allergic conditions involving inflammation of the conjunctiva and the most common forms are seasonal allergic conjunctivitis (SAC; 90% of cases) and perennial allergic conjunctivitis (PAC; 5% of cases). The main symptom is ocular itching caused by mast cell degranulation leading to the release of histamine and other mediators such as tryptase. Tryptase is a neutral protease that is selectively concentrated in the secretory granules of human mast cells and has been shown to be a sensitive and specific marker of type I hypersensitivity reaction. The objective was to ascertain the best assay method for determining the tryptase levels in tear samples and whether this can be used to determine the efficacy of non-pharmacological treatments compared to no treatment or their combined effect with anti-allergic medication for SAC and PAC. Method: Thirty patients with a history of SAC were recruited into a randomised blind study during winter months when all the patients were asymptomatic. Suitability was determined by skin prick and conjunctival provocation tests. Patients were randomly assigned to either a non-pharmacological or a pharmacological Intervention group and received each test condition assigned to their group in a randomly assigned order. Symptoms were provoked by exposure to pollen in an environmental test chamber where the temperature, humidity and grass pollen levels were set to a high pollen count day. Tear samples were taken set intervals during the visit and then processed by enzyme linked immunosorbent assay (ELISA) for the detection of tryptase levels. Preliminary results: Results are still being analysed but the preliminary optimisation experiments tested four different ELISA systems; two indirect assays and two capture ‹sandwich› assays. The results suggest that in both sandwich assay systems non-specific binding occurred which could not be easily overcome. The indirect assay systems both showed specific reactions, and the sensitivity achieved was greater with the monoclonal than the polyclonal antibody. Using these findings the indirect assay system was optimised to provide a standardised system for measuring tryptase. Initial trials using human tear samples displayed tryptase levels between 23.1 and 175.1 ng/ml; levels which fall within the anticipated range for patients with SAC. Further statistical work is needed to determine whether tryptase levels vary between the treatments 75.

Rapid tonicity induced re-localisation of endogenous aquaporin 4 in primary rat astrocytes - a therapeutic target for cytotoxic brain oedema?

It is estimated that 69-75 million people worldwide will suffer a traumatic brain injury (TBI) or stroke each year. Brain oedema caused by TBI or following a stroke, together with other disorders of the brain cost Europe €770 billion in 2014. Aquaporins (AQP) are transmembrane water channels involved in many physiologies and are responsible for the maintenance of water homeostasis. They react rapidly to changes in osmolarity by transporting water through their highly selective central pore to maintain tonicity and aid in cell volume regulation. We have previously shown that recombinant AQP1-GFP trafficking occurs in a proteinkinase C-microtubule dependant manner in HEK-293 cells in response to hypotonicity. This trafficking mechanism is also reliant on the presence of calcium and its messenger-binding protein calmodulin and results in increased cell surface expression of AQP1 in a time-scale of ~30 seconds. There is currently very little research into the trafficking mechanisms of endogenous AQPs in primary cells. AQP4 is the most abundantly expressed AQP within the brain, it is localised to the astrocytic end-feet, in contact with the blood vessels at the blood-brain-barrier. In situations where the exquisitely-tuned osmotic balance is disturbed, high water permeability can become detrimental. AQP4-mediated water influx causes rapid brain swelling, resulting in death or long term brain damage. Previous research has shown that AQP4 knock-out mice were protected from the formation of cytotoxic brain oedema in a stroke model, highlighting AQP4 as a key drug target for this pathology. As there are currently no treatments available to restrict the flow of water through AQP4 as all known inhibitors are either cytotoxic or non-specific, controlling the mechanisms involved in the regulation of AQP4 in the brain could provide a therapeutic solution to such diseases. Using cell surface biontinylation of endogenous AQP4 in primary rat astrocytes followed by neutraavidin based ELISA we have shown that AQP4 cell surface localisation increases by 2.7 fold after 5 minutes hypotonic treatment at around 85 mOsm/kg H2O. We have also shown that this rapid relocalisation of AQP4 is regulated by PKA, calmodulin, extra-cellular calcium and actin. In summary we have shown that rapid translocation of endogenous AQP4 occurs in primary rat astrocytes in response to hypotonic stimuli; this mechanism is PKA, calcium, actin and calmodulin dependant. AQP4 has the potential to provide a treatment for the development of brain oedema.

An exploration of pharmacy-specific reasons for non-adherence to prescribed medicines in a socioeconomically deprived, ethnically diverse UK cohort

Methods - Ethical approval for the study was granted by both the local National Health Service (NHS) Research Ethics Committee (REC) and Aston University’s REC. Seven focus groups were conducted between October and December 2011 in medical or community settings within inner-city Birmingham (UK). Discussions were guided by a theme plan which was developed from key themes identified by a literature review and piloted via a Patient Consultation Group. Each focus group had between 3 and 7 participants. The groups were digitally recorded and subsequently transcribed verbatim. The transcriptions were then subjected to thematic analysis via constant comparison in order to identify emerging themes. Results - Participants recognised the pharmacist as an expert source of advice about prescribed medicines, a source they frequently felt a need to consult as a result of the inadequate supply of medicines information from the prescriber. However, an emerging theme was a perception that pharmacists had an oblique profit motive relating to the supply of generic medicines with frequent changes to the ‘brand’ of generic supplied being attributed to profit-seeking by pharmacists. Such changes had a negative impact on the patient’s perceived efficacy of the therapy which may make non-adherence more likely. Conclusions - Whilst pharmacists were recognised as medicines experts, trust in the pharmacist was undermined by frequent changes to generic medicines. Such changes have the potential to adversely impact adherence levels. Further, quantitative research is recommended to examine if such views are generalisable to the wider population of Birmingham and to establish if such views impact on adherence levels.