A pilot study of the effectiveness of D-cycloserine during cue-exposure therapy in abstinent alcohol-dependent subjects.

RATIONALE: Cue-exposure therapy (CET) has been advocated as a potentially effective treatment of addictive behaviours. Strategies that enhance learning may improve the outcome of CET. D-cycloserine (DCS), a partial N-methyl-D-aspartate receptor agonist, has been shown to facilitate extinction of learned fear in rats and augment exposure-based treatment in some anxiety disorders in man. OBJECTIVE: This double-blind placebo-controlled pilot study used a cue-exposure paradigm, salient for an individual's alcohol drinking, to see if DCS would reduce cue-reactivity compared with placebo. METHODS: Sixteen abstinent, alcohol-dependent individuals were randomised to receive either a single-dose (250 mg) DCS or placebo before CET sessions, separated by at least 1 week. Subjective responses were assessed using the Alcohol Urge Questionnaire (AUQ) and visual analogue scales. Cardiovascular responses were assessed using Finapres©. RESULTS: The cue-exposure paradigm significantly increased craving assessed with the AUQ during the first session. In subsequent sessions, the degree of craving was reduced. However, no significant difference was seen between the DCS and placebo groups in any outcome measure. The variability of responses between individuals was great with more than half the groups reporting no or very small changes in AUQ scores. CONCLUSION: This is the first human study to our knowledge to assess the efficacy of DCS in facilitating CET in alcohol dependence. The high proportion of subjects with little or no response to cue-exposure would make any effect of DCS very difficult to detect. It is important that future studies carefully consider the criteria for inclusion.

A multi centre telephone survey of compliance with postoperative instructions.

Patients undergoing procedures under general anaesthesia as day cases are routinely given a set of instructions regarding activities to avoid in the first 24 h after discharge. Day surgery units generally specify the need for a responsible carer from time of discharge for a period of 24 h. This study looks at the compliance of 240 patients with postoperative instructions. Of the patients studied, 4.1% drove, 1.7% made important decisions, 3.3% drank alcohol, 0.8% took sedatives and 10% cooked, ironed or looked after children. All patients were discharged into the care of a responsible adult. However, 13.3% failed to have a carer with them for 24 h and 1.3% spent the night alone at home. Of our cohort, 25% were unable to comply with the postoperative instructions in full. The majority of non-compliance occurred on the day following surgery, suggesting that patients may feel that the advice is excessively cautious.

Remifentanil in combination with propofol for spontaneous ventilation anaesthesia.

We have investigated the effect of four doses of remifentanil on the incidence of respiratory depression and somatic response at incision. Remifentanil was administered as a loading dose of 0.125, 0.25, 0.375 or 0.5 microgram kg-1 and at a maintenance infusion rate of 0.025, 0.05, 0.075 or 0.1 microgram kg-1 min-1, respectively, with an infusion of propofol 6 mg kg-1 h-1. Responses occurred in 88% of patients with remifentanil 0.025 microgram kg-1 min-1 compared with 30-40% in the other groups. Respiratory depression after incision increased from 6% with remifentanil 0.025 microgram kg-1 min-1 to 73% with 0.1 microgram kg-1 min-1. Increases in propofol infusion rate to 7.2-8.4 mg kg-1 h-1 produced adequate maintenance of anaesthesia. Reductions in remifentanil doses to 0.025-0.05 microgram kg-1 min-1 resulted in adequate respiration at the end of surgery in 88% of patients. Maintenance infusions of the two drugs for spontaneous ventilation are likely to be in these ranges. However, the ideal loading doses and infusion rates for induction remain to be established.

Stereotaxic atlas of the brainstem of the muskrat, Ondatra zibethicus.

The muskrat is an aquatic rodent of moderate size and possesses dramatic respiratory and cardiovascular behaviors in response to submersion, stimulation of the upper respiratory tract, or environmental cues. This report provides a stereotaxic atlas of the muskrat's brainstem in the transverse plane to facilitate studies requiring an accurate localization of discrete brain structures. Plates are presented of brainstem sections between the obex and superior colliculus separated by 450 microns. Each figure shows a Nissl stained hemisection complemented by a line drawing. Our data shows mature muskrats have relatively uniform craniometric dimensions promoting their use for stereotaxic placements in their brains.

The muskrat in biomedical research.

Muskrats are aquatic rodents of moderate size which are plentiful throughout North America, but are not used commonly in the laboratory. Recently, we tested the feasibility of muskrats as experimental models and have found them to be acquired and cared for easily in conventional laboratory animal facilities. Some of their natural characteristics and diseases are described. The husbandry techniques that we used are presented and form a base for the preparation of future guidelines for the maintenance and use of feral animals in research. The results of some initial experiments testing the muskrat's utility for investigations of cardiorespiratory control mechanisms also are presented. Our data show that even anesthetized muskrats possess brisk and dramatic cardiovascular and respiratory reflexes. Our findings that their brains possess the cytoarchitectural and myeloarchitectural features comparable to other mammals, combined with their relative uniformity in size, has allowed us to locate specific neuronal loci stereotaxically. We suggest that the muskrat be considered as an experimental animal model for studies of the neural control of cardiorespiratory systems.

Preservation of the dissected and surgical anatomic detail in the human temporal bone.

Preservation and usefulness of human gross temporal bones that have been dissected or drilled have always been a problem. This article describes application of the technique of plastination developed by von Hagens to the temporal bone. The use of this technique permits development of a collection of both anatomically dissected and surgically drilled temporal bones which can be studied by the otolaryngologist at any level. The procedure involves impregnation of the specimen with uncured polymers--a silicone rubber of medium viscosity followed by curing in a vapor bath. The advantages of this technique are that the plastinated temporal bone can be studied and handled without any unpleasant odor and there is no need for liquid preservation. The potential problem of the specimen drying out and becoming useless is thus avoided.