Effects of naloxone and naltrexone on meal patterns of freely-feeding rats

The effects of naloxone and naltrexone on the night-time meal patterning of freely-feeding male rats were investigated using a Kissileff-type eatometer. Naloxone (5.0 mg/kg) and naltrexone (2.5 mg/kg) reduced intake for two hours after IP injection. This effect resulted from a shortening of duration of meals and an extension of postmeal intervals. Unlike other anorexic agents neither drug affected meal frequency or the eating rate within meals. These particular opioid antagonists therefore appear to produce anorexia by advancing meal termination and extending the inhibition of feeding which follows a meal. These specific changes in the structure of the meal pattern consolidate previous findings and support the hypothesis that naloxone and naltrexone reduce food intake in rats by promoting satiation and prolonging satiety.     

Take‐home naloxone and the politics of care

‘Take‐home naloxone’ refers to a life‐saving intervention in which a drug (naloxone) is made available to nonmedically trained people for administration to other people experiencing an opioid overdose. In Australia, it has not been taken up as widely as would be expected, given its life‐saving potential. We consider the actions of take‐home naloxone, focusing on how care relations shape its uses and effects. Mobilising Science and Technology Studies insights, we suggest that the uses and effects of naloxone are co‐produced within social relations and, therefore, this initiative ‘affords’ multiple outcomes. We argue that these affordances are shaped by a politics of care, and that these politics relate to uptake. We analyse two complementary case studies, drawn from an interview‐based project, in which opioid consumers discussed take‐home naloxone and its uses. Our analysis maps the ways take‐home naloxone can afford (i) a regime of care within an intimate partnership (allowing a terminally ill man to more safely consume opioids) and (ii) a political process of care (in which a consumer takes care of others treated with the medication by administering it ‘gently’). We conclude by exploring the political affordances of a politics of care approach for the uptake of take‐home naloxone.     

A multivariate meta-analysis approach for reducing the impact of outcome reporting bias in systematic reviews

Multivariate meta‐analysis allows the joint synthesis of multiple correlated outcomes from randomised trials, and is an alternative to a separate univariate meta‐analysis of each outcome independently. Usually not all trials report all outcomes; furthermore, outcome reporting bias (ORB) within trials, where an outcome is measured and analysed but not reported on the basis of the results, may cause a biased set of the evidence to be available for some outcomes, potentially affecting the significance and direction of meta‐analysis results. The multivariate approach, however, allows one to ‘borrow strength’ across correlated outcomes, to potentially reduce the impact of ORB. Assuming ORB missing data mechanisms, we aim to investigate the magnitude of bias in the pooled treatment effect estimates for multiple outcomes using univariate meta‐analysis, and to determine whether the ‘borrowing of strength’ from multivariate meta‐analysis can reduce the impact of ORB. A simulation study was conducted for a bivariate fixed effect meta‐analysis of two correlated outcomes. The approach is illustrated by application to a Cochrane systematic review. Results show that the ‘borrowing of strength’ from a multivariate meta‐analysis can reduce the impact of ORB on the pooled treatment effect estimates. We also examine the use of the Pearson correlation as a novel approach for dealing with missing within‐study correlations, and provide an extension to bivariate random‐effects models that reduce ORB in the presence of heterogeneity. Copyright © 2012 John Wiley & Sons, Ltd.     

Magnesium and Fluoride Distribution in Human Cementum with Age

Sixty-two human teeth, obtained from subjects aged 11 to 80 years, were used to determine the magnesium and fluoride concentration and distribution with age in human cementum. Transverse sections were prepared from the root region of teeth. Samples, each 30 μm thick, were abraded in sequence from the cementum surface and the cemento-dentine junction by an abrasive micro-sampling technique. Magnesium concentrations were lower in the cementum surface, and increased towards the cemento-dentine junction (CDJ), while fluoride concentrations were higher in cementum surfaces and tended to decrease towards CDJ. Fluoride distribution patterns were similar to that reported earlier while average fluoride concentration increased with age, however, either no change or decreasing tendencies were observed with magnesium. Received: 5 January 1998 / Accepted: 20 July 2000 / Online publication: 2 November 2000     

Asbestos fibres in bronchoalveolar lavage fluid from asbestos workers: examination by electron microscopy

The uncoated and coated fibre load in bronchoalveolar lavage (BAL) fluid was assessed using light microscopy, scanning electron microscopy, and x ray microanalysis in 15 subjects with previous, unprotected exposure to asbestos, including three with clinical and radiological evidence of asbestosis, and in 13 urban dwelling control subjects with no known occupational exposure to asbestos. The mean ferruginous body count per ml BAL fluid in asbestos exposed subjects as determined by light microscopy was 52 (range 0-333). No ferruginous bodies were detected in control subjects. The mean fibre count per ml BAL fluid in asbestos exposed subjects as determined by electron microscopy was 793 (133-3700), significantly greater than 239 (44-544) in controls (p less than 0.05). Electron microscopic counts correlated with duration of previous exposure to asbestos (r = 0.47, p less than 0.05) and with percentage neutrophil counts (r = 0.53, p less than 0.025). There was no relation between electron microscopic fibre counts and light microscopic ferruginous body counts. In 11 asbestos exposed cases x ray microanalysis confirmed the presence of asbestos and in six the asbestos fibre type was clearly identified. Of five subjects showing no asbestos bodies by light microscopy, all showed fibres by electron microscopy, and in three cases the presence of asbestos was confirmed by microanalysis. Among control subjects, fibres were either large organic fibres or smaller particles which microanalysis showed were not asbestos. In only one control case were a few fibres identified which were confirmed as asbestos fibres on microanalysis. Electron microscopic examination of BAL fluid may confirm past exposure to asbestos and probably gives a crude quantitative estimate of asbestos load.     

Local anaesthetic adjuncts for peripheral regional anaesthesia: a narrative review

Moderate-to-severe postoperative pain persists for longer than the duration of single-shot peripheral nerve blocks and hence continues to be a problem even with the routine use of regional anaesthesia techniques. The administration of local anaesthetic adjuncts, defined as the concomitant intravenous or perineural injection of one or more pharmacological agents, is an attractive and technically simple strategy to potentially extend the benefits of peripheral nerve blockade beyond the conventional maximum of 8–14 hours. Historical local anaesthetic adjuncts include perineural adrenaline that has been demonstrated to increase the mean duration of analgesia by as little as just over 1 hour. Of the novel local anaesthetic adjuncts, dexmedetomidine and dexamethasone have best demonstrated the capacity to considerably improve the duration of blocks. Perineural dexmedetomidine and dexamethasone increase the mean duration of analgesia by up to 6 hour and 8 hour, respectively, when combined with long-acting local anaesthetics. The evidence for the safety of these local anaesthetic adjuncts continues to accumulate, although the findings of a neurotoxic effect with perineural dexmedetomidine during in-vitro studies are conflicting. Neither perineural dexmedetomidine nor dexamethasone fulfils all the criteria of the ideal local anaesthetic adjunct. Dexmedetomidine is limited by side-effects such as bradycardia, hypotension and sedation, and dexamethasone slightly increases glycaemia. In view of the concerns related to localised nerve and muscle injury and the lack of consistent evidence for the superiority of the perineural vs. systemic route of administration, we recommend the off-label use of systemic dexamethasone as a local anaesthetic adjunct in a dose of 0.1–0.2 mg.kg⁻¹ for all patients undergoing surgery associated with significant postoperative pain.