An investigation of factors associated with depressive symptoms among a sample of regular ecstasy consumers

AIMS/OBJECTIVES

Methylenedioxymethamphetamine affects the central serotonergic system, and there is some evidence for an association between ecstasy use (drugs sold as methylenedioxymethamphetamine) and depression. The aim of the present study was to investigate the incidence of self-reported depression and associated help-seeking among a sample of regular ecstasy users. A further aim was to examine the correlates of depressive symptomatology in this population.

MATERIALS AND METHODS

100 regular ecstasy consumers (at least monthly use) were interviewed as part of the Ecstasy and Related Drug Reporting System in Tasmania, Australia. Participants were also administered epidemiological measures of depression (Center for Epidemiological Studies Depression Scale) and psychological distress (Kessler Psychological Distress Scale).

RESULTS

One quarter (23%) of participants self-reported recent experience of depression, a rate notably greater than the general population. However, only one third of these participants had attended a health professional for this issue. A range of drug use factors (e.g. frequency and quantity of ecstasy use, frequent cannabis or methamphetamine use, intravenous drug use, polydrug use, binge drug use, harmful alcohol use, and elevated psychological dependence scores for ecstasy and methamphetamine) were associated with high levels of depressive symptomatology.

CONCLUSION

These findings are consistent with an association between depressive symptomatology and ecstasy and other drug use. Harm reduction strategies which target drug use factors such as those identified in this study may also aid in the reduction of the experience of depression. Considering the low levels of help-seeking among this population, improving awareness and access to information and treatment for depression may also be important.

The behavioural and electrophysiological effects of visual task difficulty and bimanual coordination mode during dual-task performance

The difficulty of a visual three stimulus and a bimanual coordination task was manipulated by varying discrimination difficulty (easy, hard) and coordination mode (in-phase, anti-phase) respectively. Electroencephalographic activity was recorded from 32 sites whilst participants (n = 16) completed four dual-task conditions in counterbalanced order. Longer reaction time and lower accuracy were found for the hard relative to the easy visual task and, for the hard visual task, accuracy was lower under anti-phase relative to in-phase conditions. Amplitude and latency of event-related potential components P3a and P3b were recorded and measured. There was a reduction in P3b amplitude and increase in P3a amplitude for the hard visual task overall and a further reduction in frontal P3b amplitude under the more demanding anti-phase condition. For the easy visual task, however, P3b and P3a amplitude were greater under the anti-phase relative to in-phase coordination condition at left hemisphere frontal sites. These findings suggest that the attentional cost of stabilising anti-phase bimanual coordination is largely associated with top-down automatic processes subserved by the frontal attentional network.

Population quantile-quantile plots for monitoring assay performance in newborn screening

Immunoreactive trypsinogen (IRT) used in screening for cystic fibrosis is heterogeneous, poorly characterized, and displays marked matrix effects when incorporated into blood spots, making long-term control of assay calibration difficult. The cut-off required to select a fixed proportion of samples (0.5% for the UK protocol) for second-tier mutation analysis varies over time, partly owing to slight differences in calibration of individual lots of assay kit. To investigate this and possible inter-laboratory differences in analytical performance, we developed a monitoring system based on the distribution of measured IRT concentrations in the screened samples. Results were collected fortnightly from five UK screening laboratories in the form of numbers of samples in histogram 'bins' of IRT concentration. These data were converted to cumulative percentages and the IRT concentrations at fixed centiles then approximated by triangulation. The quantile-quantile plot of any subset (by laboratory or by kit lot) of these data using pooled results (all-laboratories all-kit-lots, approximately 270,000 samples) as the reference distribution is analogous to a calibration curve and gives a measure of bias in terms of sensitivity (slope) and baseline (y-intercept). This allows a revised 99.5th centile cut-off for each subset to be calculated directly. A similar approach has allowed inter-laboratory comparison of tandem-mass spectrometric assays for free carnitine (with emphasis on low values) and phenylalanine and has demonstrated that apparently trivial differences in instrumentation and procedures have resulted in marked variation in resultant assay performance.

Body posture during simulated tracheal intubation

Seventeen experienced anaesthetists and 15 novices were filmed intubating the trachea of a training manikin. Measurements were made of the distance from manikin's chin to subject's nose and of the angles at the elbow, the shoulder and of the forearm with the horizontal. Trained subjects stood further back (trained: median 43 cm, interquartile range 41-56 cm; novices 35 cm, 26-38 cm; Mann-Whitney U, p < 0.01), with a straighter arm (trained elbow angle: 108 degrees, 99-121 degrees; novices': 92 degrees, 88-102 degrees; Mann-Whitney U, p < 0.01). Trained subjects tended to hold the laryngoscope closer to the hinge, with a pincer grip; novices were more likely to use a full grip of the handle. Trainers should consider giving novices explicit instructions on how to stand and how to hold the laryngoscope.

Iron and atherosclerosis: inhibition by the iron chelator deferiprone (L1)

BACKGROUND

Accumulating evidence suggests that oxidative modification of lipoproteins may play a significant role in atherogenesis. In this study, we hypothesized that the iron chelator deferiprone (L1) would function as an antioxidant and decrease atherosclerosis progression.

MATERIALS AND METHODS

For the in vitro studies, human low-density lipoprotein (LDL) was collected and then subjected to oxidation by either hemin/H2O2 or copper sulfate in the presence of various concentrations of L1. Lag time to oxidation was measured to assess antioxidant activity of L1. In addition, human umbilical vein endothelial cells (HUVEC) were subjected to oxidized LDL in the presence of varying concentrations of L1 to assess the antioxidant cytoprotective ability of L1. For the in vivo studies, rabbits (n = 21) were maintained on a 0.25% by weight cholesterol diet for 10 weeks; 9 rabbits also received twice daily L1 by gavage (total dose = 100 mg/kg/day). Lipid profiles were measured during the study. At 10 weeks, rabbits were sacrificed, and thoracic aorta cholesterol content (TACC) and planimetry were determined to assess atherosclerosis severity.

RESULTS

In vitro, L1 prevented oxidation of LDL and protected HUVEC from the cytotoxic effects of oxidized LDL in a concentration-dependent manner. In vivo, L1 reduced TACC (P = 0.001), while also significantly decreasing total plasma cholesterol (P = 0.003), very-low-density lipoprotein cholesterol (P = 0.01), and LDL cholesterol (P = 0.002) compared to control animals. However, no significant differences between L1-treated animals and controls were evident for the surface area of plaque involvement by planimetry (P = 0.3) or in the serum iron levels (P = 0.3).

CONCLUSIONS

These results confirm that L1 possesses antioxidant activity in vitro and may reduce atherogenesis in vivo.

Lack of effect of vitamin E on cholesteryl ester transfer and lipoprotein composition in cholesterol-fed rabbits

The concentration and activity of cholesteryl ester transfer protein (CETP) is increased in plasma in hypercholesterolemic humans and in experimental animals fed cholesterol. While the concentration of lipo-proteins appears to be the major determinant of CETP activity, we have found previously that dietary measures and pharmacologic agents that alter their lipid composition reduce the activity of CETP in plasma (CET). Since vitamin E is lipophilic and is incorporated into lipoproteins, we have examined the question of whether it too attenuates CET in cholesterol-fed New Zealand White rabbits prior to and 14 weeks after treatment with differing doses (5, 15, 30, 45 mg/kg) of vitamin E. Plasma triglycerides (TG), cholesterol (TC) and phospholipids (Lys, Sph, Lec, PI, PE) all increased significantly to a comparable degree in the rabbits fed cholesterol compared to those fed chow (p < 0.05; p < 0.01); the levels achieved were similar in the vitamin E-treated and untreated groups. As was observed with plasma lipids, cholesteryl ester transfer (CET) was accelerated to the same degree in each of the cholesterol-fed groups independent of whether they received vitamin E compared to chow-fed controls (p < 0.01) and the distribution of cholesterol in apo-B containing lipoproteins (VLDL, IDL, and LDL) was similar in the vitamin E-treated and untreated groups. These findings indicate that vitamin E has no discernible effect on CET when cholesterol levels are markedly elevated.

Epidural anaesthesia in von Hippel-Lindau disease. Management of childbirth and anaesthesia for caesarean section

The management of childbirth, including epidural anaesthesia for Caesarean section is described in a patient with von Hippel-Lindau disease. The reasons for the choice of epidural anaesthesia are explained and the anaesthetic significance of the disease is discussed.

Acid-base control during hypothermia. Acid-base control in children during hypothermia without temperature correction of pH and PCO2

In 28 children undergoing cardiopulmonary bypass with deep hypothermia for open heart surgery, an attempt was made to maintain pH at 7.4 not corrected for temperature by varying the CO2 concentration supplied to the oxygenator so that the PaCO2 was 5.33 kPa, not corrected for temperature. One to two percent CO2 gave satisfactory results. Five percent CO2 had previously been given. No adverse clinical side effects were noted, and the acid-base status remained stable for 24 hours in 16 patients. There are strong theoretical reasons for maintaining a pH of 7.4, uncorrected for temperature, during hypothermia and a clinical impression was gained of better myocardial function and improved systemic and cerebral perfusion.