Drug driving from a user's perspective

The bulk of research into drug driving in Australia has been undertaken from a road safety orientation where drug driving is viewed within the broader context of road safety and driver behaviour. Such a specific focus precludes the broader behavioural, contextual and cultural issues associated with substance use. This study aimed to address this issue by focusing on drug driving behaviour within the context of illicit substance use. A series of focused interviews were conducted with 211 illicit drug users from urban and regional centres. A consistent theme identified in the interviews was that drug driving was not necessarily viewed as risky behaviour but rather as an outcome of illicit substance use. Further, some interviewees saw their drug use as enhancing their driving skills and frequently the motor vehicle was viewed as a safe place to use. Overall there was agreement among interviewees that the likelihood of being apprehended for drug driving by police was minimal; this perception was reinforced by past experience. The lack of concern for detection of drug driving behaviour suggests that research should continue into the development and implementation of enforcement programs and roadside detection.     

Localization of acetylcholine receptors and cholinesterase on nerve-contacted and noncontacted muscle cells grown in the presence of agents that block action potentials

The possible role of nerve activity in triggering changes in the localization of acetylcholine receptors (AChRs) and cholinesterase (ChE) on nerve-contacted Xenopus muscle cells has been assessed. The localization of these molecules was examined on nerve-contacted and noncontacted muscle cells in cultures of spinal cord and myotomal muscle derived from Xenopus embryos. Sites of high AChR density were revealed by staining with fluorescent alpha-bungarotoxin and sites of ChE localization were revealed histochemically. Localization of AChRs and ChE at sites of nerve-muscle contact occurred when the culture medium contained 1.2 micron tetrodotoxin (TTX), 1.2 micron TTX, 10 mM magnesium, and no calcium salts, 1.2 micron TTX and 2 mM manganese, or 106 mM potassium methyl sulfate instead of sodium chloride. The nerve-contacted muscle cells in each of these modified culture media also exhibited a reduced incidence of AChR and ChE patches away from the site of contact. It is concluded that the neural factor(s) that triggers the local and remote changes in AChR and ChE distribution can be supplied to the neurites and externalized in the absence of nerve impulses, and that the nerve and muscle cells can interact even when they are largely depolarized.     

Methodological issues in drug-drug conditioning in rats: nonassociative factors in heart rate and avfail.

Sodium pentobarbital injections followed 30 min later by d-amphetamine sulfate produce an effect over trials in the form of an increase in heart rate in response to pentobarbital in relation to rats that receive the 2 drugs 24 hr apart (long-delayed control: Revusky, Davey, & Zagorski, 1989). This study found equivalent increases in heart rate in forward and backward groups in relation to a long-delayed control regardless of whether training or testing was carried out in a heart rate recording apparatus or in the home cage, which suggests that a drug interaction due to drug administrations in forward and backward groups has yet to be eliminated in accounting for the heart rate effect. Comparison of backward and long-delayed controls in a drug-drug procedure that used a taste aversion test revealed that both forward and delayed pairings can produce attenuated aversions in relation to a backward group regardless of whether the unconditional stimulus is amphetamine (Experiment 1) or lithium chloride (Experiment 2).     

Emergency use of the laryngeal mask airway in severe upper airway obstruction caused by supraglottic oedema

We report two cases of severe upper airway obstruction caused by supraglottic oedema which developed rapidly at the time of anaesthesia. Conventional methods to relieve the obstruction failed and it was only overcome when a laryngeal mask airway (LMA) was inserted and positive pressure applied manually during inspiration. In one case a fibrescope was passed via the LMA and this revealed two cushions of oedematous false vocal cords protruding into the bowel of the LMA which were pushed out of the way when positive pressure was applied during inspiration. We believe that the LMA should be considered in the emergency management of severe upper airway obstruction even when this involves supraglottic oedema.      

Does too much urology damage your eyesight? Study of macular function.

A study comparing the macular function of both eyes of 130 urological surgeons was carried out to investigate whether the increased light exposure to the endoscoping eye caused any deterioration of macular function. The non-endoscoping eye was used as a control. A sophisticated computer test of colour contrast sensitivity was used. The computer assesses the degree of brightness at which the subject is just able to detect a coloured grating, and for each eye this is expressed as a threshold for the red/green axis and the blue/yellow (tritan) axis. The subjects also completed a questionnaire about their working patterns and their general and ophthalmic history and had a brief examination of the fundus. The results do not suggest that urologists are suffering any significant macular damage as a result of their work with endoscopes.     

Effect of sodium hyaluronate (0.1%) on break-up time (NIBUT) in patients with dry eyes.

We evaluated the effect of 0.1% sodium hyaluronate (unpreserved) in 10 patients with dry eyes. The precorneal tear film break-up time was assessed by the non-invasive technique, and the severity of symptoms was recorded before and after treatment on a 0 to +3 scale. It was found that the tear film stability was significantly increased (p less than 0.05) in eyes treated with sodium hyaluronate. The symptoms of grittiness and burning were also significantly alleviated in the treated eyes.