The relationship between social network factors, HIV, and Hepatitis C among injection drug users in Chennai, India

Objective

The purpose of this study was to examine whether social network factors predict HIV and Hepatitis C (HCV) serostatus after controlling for individual-level factors at baseline among a cohort of male injection drug users in Chennai, India.

Methods

The sample, which was recruited through street outreach, consists of 1078 males who reported having injected drugs in the last 6 months.

Results

The participants reported 3936 social support and risk network members. HIV and HCV positive serostatus were negatively associated with network member providing emotional support, and positively associated with network member providing material support. In addition, HCV positivity was associated with network member being an active drug user known for more than 10 years and network member being male kin networks, even after adjusting for individual demographic factors and risk behaviors.

Conclusions

These findings suggest that social network factors are significantly linked to HIV and HCV status among IDUs in Southern India and highlight the mixed effects of social capital on health. Future HIV/HCV prevention efforts should incorporate IDU peers to alter drug network injection risk norms. For drug users who have minimal network support, support groups and other informal and formal support mechanisms may be need to help them with health care and psychological support needs for dealing with HIV/HCV.     

Anxiogenic and stress-inducing effects of peripherally administered acetaldehyde in mice: similarities with the disulfiram-ethanol reaction

Peripheral accumulation of acetaldehyde, the first metabolite of ethanol, produces autonomic responses in humans called “flushing”. The aversive characteristics of flushing observed in some populations with an isoform of aldehyde dehydrogenase (ALDH2) less active, are the basis for treating alcoholics with disulfiram, an ALDH inhibitor. Although ethanol and centrally formed acetaldehyde have anxiolytic effects, peripheral accumulation of acetaldehyde may be aversive in part because it is anxiogenic.

Objectives

We investigated the effect of direct administration of acetaldehyde on behavioral measures of anxiety and on hormonal markers of stress in mice. The impact of disulfiram on the anxiolytic actions of ethanol was evaluated. Acetate (a metabolite of acetaldehyde) was also studied.

Methods

CD1 male mice received acetaldehyde (0, 25, 50, 75 or 100 mg/kg) at different time intervals and were assessed in the elevated plus maze and in the dark-light box. Corticosterone release after acetaldehyde administration was also assessed. Additional experiments evaluated the impact of disulfiram on the anxiolytic effect of ethanol (0 or 1 mg/kg), and the effect of acetate on the plus maze.

Results

Direct administration of acetaldehyde (100 mg/kg) had an anxiogenic effect at 1, 11 or 26 min after IP administration. Acetaldehyde was ten times more potent than ethanol at inducing corticosterone release. Disulfiram did not affect behavior on its own, but blocked the anxiolytic effect of ethanol at doses of 30 and 60 mg/kg, and had an anxiogenic effect at the highest dose (90 mg/kg) when co-administered with ethanol. Acetate did not affect any of the anxiety parameters.

Conclusions

Peripheral administration or accumulation of acetaldehyde produces anxiogenic effects and induces endocrine stress responses. This effect is not mediated by its metabolite acetate.     

BZP-party pills: a review of research on benzylpiperazine as a recreational drug

Background

BZP-party pills are yet another ‘designer drug’ which mimics the stimulant qualities of amphetamines and MDMA/Ecstasy. As legal markets for the substance have developed in the last decade (especially amongst young people) so has public and governmental concern.

Methods

This article provides a summary of the available international research on benzylpiperazine (BZP) and its popular use in the compound form known as ‘party pills’. Through performing an analysis of the available medical and social scientific literature, the review outlines current knowledge on the compound, the prevalence of usage of BZP-party pills, as well as the associated harms, risks and rationales for use of the drug.

Results

Despite moves towards legislative control of BZP-party pills, the evidence presented suggests limited social and health harms associated with the drug, although research on long term effects is a significant gap in the literature. It also remains inconclusive as to whether BZP-party pills act as a ‘gateway’ to illegal drugs or, conversely, play a role in harm reduction with illegal drug users turning to legal alternatives; there is some evidence for both positions.

Conclusion

With increasing controls of BZP-party pills, and with the increasing numbers of ‘legal highs’ and new designer drugs on the market, we conclude that new legal alternatives will continue to surface to replace the drug in the future. Considering a harm reduction approach to drug taking, it is suggested that policy makers consider the creation of a legal holding category which restricts and regulates the market in legal highs whilst the social and health harms associated with each drug can be thoroughly investigated.     

Biological definition of multiple chemical sensitivity from redox state and cytokine profiling and not from polymorphisms of xenobiotic-metabolizing enzymes

Background

Multiple chemical sensitivity (MCS) is a poorly clinically and biologically defined environment-associated syndrome. Although dysfunctions of phase I/phase II metabolizing enzymes and redox imbalance have been hypothesized, corresponding genetic and metabolic parameters in MCS have not been systematically examined.

Objectives

We sought for genetic, immunological, and metabolic markers in MCS.

Methods

We genotyped patients with diagnosis of MCS, suspected MCS and Italian healthy controls for allelic variants of cytochrome P450 isoforms (CYP2C9, CYP2C19, CYP2D6, and CYP3A5), UDP-glucuronosyl transferase (UGT1A1), and glutathione S-transferases (GSTP1, GSTM1, and GSTT1). Erythrocyte membrane fatty acids, antioxidant (catalase, superoxide dismutase (SOD)) and glutathione metabolizing (GST, glutathione peroxidase (Gpx)) enzymes, whole blood chemiluminescence, total antioxidant capacity, levels of nitrites/nitrates, glutathione, HNE-protein adducts, and a wide spectrum of cytokines in the plasma were determined.

Results

Allele and genotype frequencies of CYPs, UGT, GSTM, GSTT, and GSTP were similar in the Italian MCS patients and in the control populations. The activities of erythrocyte catalase and GST were lower, whereas Gpx was higher than normal. Both reduced and oxidised glutathione were decreased, whereas nitrites/nitrates were increased in the MCS groups. The MCS fatty acid profile was shifted to saturated compartment and IFNgamma, IL-8, IL-10, MCP-1, PDGFbb, and VEGF were increased.

Conclusions

Altered redox and cytokine patterns suggest inhibition of expression/activity of metabolizing and antioxidant enzymes in MCS. Metabolic parameters indicating accelerated lipid oxidation, increased nitric oxide production and glutathione depletion in combination with increased plasma inflammatory cytokines should be considered in biological definition and diagnosis of MCS.     

Psychosocial treatments for cocaine dependence: the role of depressive symptoms

Background

The association between cocaine use and depression has been frequently observed. However, less is known about the significance of depression in the treatment of cocaine use disorders. This study examined possible interrelations between drug use and depression severity among cocaine-dependent patients in psychosocial treatments for cocaine dependence.

Methods

Monthly assessed drug use and depression severity scores of N = 487 patients during 6-month psychosocial treatments for cocaine dependence were analyzed using hybrid latent growth models.

Results

Results indicated a moderate but statistically significant (z = 3.13, p < .01) influence of depression severity on increased drug use in the upcoming month, whereas drug use did not affect future depression severity.

Conclusions

Findings suggest that depression symptoms are an important predictor of drug use outcomes during psychosocial treatments for cocaine dependence and, hence, underline the importance of adequately addressing depression symptoms to improve treatment outcomes.     

Studying up harm reduction policy: the office as an assemblage

Background

By recounting the making of the office that contributed to the implementation of the harm reduction policy in Taiwan, this paper aims to answer two questions: Who and what assembled to make this policy possible? Which conceptual tool works best to understand what this policy-making was all about?

Methods

The research was designed as a multi-sited qualitative study whose materials were collected through archival research, in-depth interviews, and direct field observation. The data were analysed on the basis of the constructivist version of grounded theory.

Result

Formulating the office as an assemblage with heterogeneous components and shifting territories, the present work endeavours to show how it was constituted by way of guanxi, or webs of social relationship that blur the boundary between the private and the public, the governmental and the social.

Conclusion

This “studying up” approach is hoped to elicit more research on the office in which harm reduction policies are made into the backdrop of drug users on the street.     

Tetrodotoxin reduces cue-induced drug craving and anxiety in abstinent heroin addicts

Background

Tetrodotoxin (TTX) is a neurotoxin found in puffer fish and other marine animals. New clinical studies suggest that low-dose TTX can safely relieve severe, treatment-resistant cancer pain. The therapeutic potential of TTX in addiction is supported by studies in laboratory animals. The purpose of this double-blind, placebo-controlled study was to assess the effect of a single intramuscular dose of TTX on cue-induced craving and anxiety in abstinent heroin addicts.

Methods

Forty-five abstinent heroin addicts were randomly assigned to three treatment groups: placebo, 5 µg TTX, or 10 µg TTX. Participants were exposed to a neutral video or a heroin-related video. Craving, anxiety, blood pressure, and heart rate were measured pre- and post-exposure.

Results

Heroin-related cues increased both craving and anxiety and had no effect on blood pressure and heart rate. A single dose of TTX dose-dependently attenuated the increases in craving and anxiety while having no effect on blood pressure or heart rate.

Conclusion

The results suggest that low-dose TTX is acutely effective in reducing cue-induced increases in heroin craving and associated anxiety.     

Treatment costs of hepatitis C infection among injection drug users in Canada, 2006-2026

Background

Canadian injection drug users (IDUs) are at high risk of hepatitis C virus infection (HCV). However, little is known about the costs associated with their HCV-related medical treatment. We estimated the medical costs of treating HCV-infected IDUs from 2006 to 2026.

Methods

We employed a Markov model of entry through birth or immigration to exposure-related behaviours or experiences, HCV infection, progression to HCV sequelae and mortality for active and ex-IDUs in Canada. We estimated direct and indirect treatment costs using data from the Ontario Case Costing Initiative (OCCI).

Result

Approximately 137,000 IDUs will suffer from HCV-related disease each year until 2026. Applying the OCCI cost data to the prevalence of HCV-related disease from 2006 to 2026 yielded an estimated cost of $3.96 billion CND to treat HCV-infected IDUs.

Conclusions

Substantial costs are associated with the treatment of HCV-related disease among Canadian IDUs. Given the lack of effective HCV prevention strategies in Canada, we must develop targeted evidence-based responses to prevent HCV transmission and ensure appropriate allocation of medical resources to meet the present and future treatment needs of HCV-infected IDUs.     

Estimating national-level syringe availability to injecting drug users and injection coverage: Switzerland, 1996-2006

Background

Measuring syringe availability and coverage is essential in the assessment of HIV/AIDS risk reduction policies. Estimates of syringe availability and coverage were produced for the years 1996 and 2006, based on all relevant available national-level aggregated data from published sources.

Methods

We defined availability as the total monthly number of syringes provided by harm reduction system divided by the estimated number of injecting drug users (IDU), and defined coverage as the proportion of injections performed with a new syringe, at national level (total supply over total demand). Estimates of supply of syringes were derived from the national monitoring system, including needle and syringe programmes (NSP), pharmacies, and medically prescribed heroin programmes. Estimates of syringe demand were based on the number of injections performed by IDU derived from surveys of low threshold facilities for drug users (LTF) with NSP combined with the number of IDU. This number was estimated by two methods combining estimates of heroin users (multiple estimation method) and (a) the number of IDU in methadone treatment (MT) (non-injectors) or (b) the proportion of injectors amongst LTF attendees. Central estimates and ranges were obtained for availability and coverage.

Results

The estimated number of IDU decreased markedly according to both methods. The MT-based method (from 14,818 to 4809) showed a much greater decrease and smaller size of the IDU population compared to the LTF-based method (from 24,510 to 12,320). Availability and coverage estimates are higher with the MT-based method. For 1996, central estimates of syringe availability were 30.5 and 18.4 per IDU per month; for 2006, they were 76.5 and 29.9. There were 4 central estimates of coverage. For 1996 they ranged from 24.3% to 43.3%, and for 2006, from 50.5% to 134.3%.

Conclusion

Although 2006 estimates overlap 1996 estimates, the results suggest a shift to improved syringe availability and coverage over time.     

Cigarette, marijuana, and alcohol use and prior drug treatment among newly homeless young adults in New York City: Relationship to a history of foster care

Background

This study examined whether a history of foster care was associated with the risk for substance use among newly homeless young adults, controlling for demographics and other risk factors.

Methods

Multiple logistic regression analyses, adjusted for controls, among consecutive admissions of 424 newly homeless young adults (18-21 years), determined the association between foster care and substance use.

Results

A history of foster care was reported by 35% of the sample. Alcohol, marijuana, and cigarettes were the most frequently used substances. After adjusting for demographics, childhood emotional, physical, and sexual abuse, prior arrest, unemployment, lack of high school diploma, and family drug use, homeless young adults with histories of foster care were: three times as likely to smoke cigarettes (AOR = 3.09); more than three times as likely to use marijuana (AOR = 3.30); and almost nine times as likely to have been in drug treatment (AOR = 8.81) than those without such histories.

Conclusions

It is important to screen homeless young adults who exited foster care for substance use, particularly cigarettes and marijuana. Risk reduction interventions should be targeted and tailored to their substance prevention needs.     

Lessepsian migration and tetrodotoxin poisoning due to Lagocephalus sceleratus in the eastern Mediterranean

Background

The Suez Canal permits migration of fish from the Indo-Pacific Ocean to the Mediterranean Sea. This phenomenon (Lessepsian migration) has enabled poisonous fish species to colonize the Mediterranean Sea.

Objective

To report clinical tetrodotoxin poisoning after consumption of the Lessepsian immigrant fish Lagocephalus sceleratus caught on the Israeli coast of the eastern Mediterranean.

Case series

Thirteen patients aged 26-70 years were admitted after consuming L. sceleratus. Signs of toxicity appeared within 1 h. The main manifestations included vomiting, diarrhea, headache, paraesthesias, slurred speech, muscle weakness, dyspnea, hypertension, tachycardia, respiratory arrest, seizures and coma. Treatment was supportive, including mechanical ventilation (two patients). Patients recovered within 4 days. All fish were identified as L. sceleratus, a species known to contain tetrodotoxin.

Discussion

The diagnosis of tetrodotoxin poisoning was suggested by typical clinical manifestations together with temporal proximity to consumption of tetrodotoxin-containing fish. To the best of our knowledge, this is the first case series of tetrodotoxin poisoning reported from the eastern Mediterranean and due to L. sceleratus. Man made disruption of the ecological balance has resulted in the spread of tetrodotoxin-containing fish from the Indo-Pacific region to the Mediterranean Sea. Increased awareness is required to identify tetrodotoxin poisoning in an atypical fauna.     

5-HT induces temporomandibular joint nociception in rats through the local release of inflammatory mediators and activation of local β adrenoceptors

Objectives

The present studies assessed the effects of adolescent and adult ethanol exposure on the rewarding effects of cocaine as measured with the conditioned place preference procedure.

Methods

Male rats were exposed to intraperitoneal (IP) injections of ethanol or vehicle for 10 days [postnatal days (PNDs) 30-39 or PNDs 70-79; 2 mg/kg]. Place preference conditioning began on PND 65 or PND 105, respectively, and consisted of a baseline test followed by four conditioning cycles with either 0, 5, 10 or 20 mg/kg cocaine. Following the fourth conditioning cycle a final preference test was performed. Changes in time on the drug-paired side between the baseline and final test were analyzed.

Results

Animals exposed to vehicle (during adolescence or adulthood) showed a significant place preference at 20 mg/kg cocaine. Animals exposed to ethanol (during adolescence or adulthood) showed a significant place preference at 10 mg/kg cocaine.

Conclusions

Exposure to ethanol (adolescents or adults) sensitized the rewarding effects of cocaine. This may indicate an increase in the abuse liability of cocaine following a history of ethanol exposure.     

Neuroprotective effect of Bacopa monniera on ischemia induced brain injury

Purpose

Brain stroke is a leading cause of death without effective treatment. B. monniera, an Indian herbal medicine, exerts antioxidant activity and antistress activity by modulating the antioxidative defence system. We wanted to test if B. monniera could alleviate the ischemia induced brain injury and cognitive dysfunction in Wistar rats.

Procedure

We studied the effect of B. monniera (120 mg kg^− 1, 160 mg kg^− 1 and 240 mg kg^− 1 P.O.) on transient intracarotid artery (ICA) occlusion induced ischemia by testing the neurobehavioral and biochemical parameters on treated and control rats.

Findings

B. monniera attenuated the reduced transfer latency in ischemic rats in a step through test and showed a protective effect on ischemia induced memory impairment in the plus maze task. It also showed a marginal improvement in neurodeficit score and fore limb muscle grip strength. B. monniera reduced the infarct size in the ischemic brain. It also decreased nitrite, nitrate and lipid peroxidation and significantly improved catalase activity.

Conclusion

These observations suggest the neuroprotective and antioxidant activity of B. monniera on ischemia induced brain injury and pave the way for future investigations.     

Percutaneous penetration of 5-methoxypsoralen in rhesus monkeys

Objective and design

5-methoxypsoralen (bergapten) has been used in the treatment of psoriasis and vitiligo, and as a sun tanning accelerator. While low plasma concentrations have previously been detected, there is no data on its dermatopharmacokinetics.

Materials and methods

Three rhesus monkeys were used as a model for human skin. [14C]-5-methoxypsoralen, as a parenteral excretion control, was injected in propylene glycol with an activity of 1.12 uCi/ml at a concentration of 80 mcg/ml and urine was collected at 4, 8, 12, 24 h, and then daily for a total of 6 days. [14C]-5-methoxypsoralen was then applied topically in acetone with a dose of 1.19 mc (72 mcg) and urine was collected at 4 and 24 h and then daily for a total of 7 days. The amount excreted was corrected for the previously determined parenteral excretion kinetics.

Results

Intramuscular [14C]-5-methoxypsoralen had an average of 71.87 ± 7.77% of excretion and percutaneously applied [14C]-5-methoxypsoralen had an average of 58.4 ± 11.8% of excretion.

Conclusion

A high percentage of the administered 5-methoxypsoralen was absorbed. This provides a foundation of methodology to evaluate the efficacy of other delivery vehicles for 5-methoxypsoralen and serves as part of its dermatotoxic profile.     

Sleep disturbance and the effects of extended-release zolpidem during cannabis withdrawal

Background

Sleep difficulty is a common symptom of cannabis withdrawal, but little research has objectively measured sleep or explored the effects of hypnotic medication on sleep during cannabis withdrawal.

Methods

Twenty daily cannabis users completed a within-subject crossover study. Participants alternated between periods of ad libitum cannabis use and short-term cannabis abstinence (3 days). Placebo was administered at bedtime during one abstinence period (withdrawal test) and extended-release zolpidem, a non-benzodiazepine GABA_A receptor agonist, was administered during the other. Polysomnographic (PSG) sleep architecture measures, subjective ratings, and cognitive performance effects were assessed each day.

Results

During the placebo-abstinence period, participants had decreased sleep efficiency, total sleep time, percent time spent in Stage 1 and Stage 2 sleep, REM latency and subjective sleep quality, as well as increased sleep latency and time spent in REM sleep compared with when they were using cannabis. Zolpidem attenuated the effects of abstinence on sleep architecture and normalized sleep efficiency scores, but had no effect on sleep latency. Zolpidem was not associated with any significant side effects or next-day cognitive performance impairments.

Conclusions

These data extend prior research that indicates abrupt abstinence from cannabis can lead to clinically significant sleep disruption in daily users. The findings also indicate that sleep disruption associated with cannabis withdrawal can be attenuated by zolpidem, suggesting that hypnotic medications might be useful adjunct pharmacotherapies in the treatment of cannabis use disorders.     

Physiological and subjective effects of acute intranasal methamphetamine during extended-release alprazolam maintenance

Background

Medications development for methamphetamine dependence is ongoing, but no widely accepted, effective pharmacotherapy has been identified. Previous studies have demonstrated neurobiological perturbations to central GABA_A activity following chronic stimulant use, and that positive modulation of GABA_A receptors attenuates the neurochemical and behavioral response to stimulant drugs such as methamphetamine. Therefore, GABA_A modulators could be useful as pharmacotherapies for stimulant-use disorders.

Methods

This study tested the hypothesis that intranasal methamphetamine would be safe and well tolerated during maintenance on extended-release alprazolam (XR), and that the effects of methamphetamine would be attenuated. Eight non-treatment-seeking, stimulant-dependent individuals completed an inpatient experiment in which ascending doses of intranasal methamphetamine (0, 5, 10, 20 and 30 mg) were administered after four days of alprazolam XR maintenance (0 and 1 mg/day).

Results

Intranasal methamphetamine produced prototypical effects (e.g., increased positive subjective ratings and elevated cardiovascular signs). The combination of intranasal methamphetamine and alprazolam XR was safe and well tolerated. Alprazolam XR produced small, but orderly, reductions in some of the subjective effects of methamphetamine, and performance impairment.

Conclusions

The present results demonstrate that methamphetamine use during alprazolam XR treatment would not pose a significant safety risk. Given the potential of GABA_A positive modulators to manage certain aspects of stimulant abuse and dependence (i.e., drug-induced seizures, anxiety and stress), but the relatively small impact on the acute abuse-related effects of methamphetamine observed here, additional research with GABA_A positive modulators is warranted, but should consider their use as an adjunct component of combination behavioral and/or drug treatment.     

Rapid absorption of nicotine from new nicotine gum formulations

Rationale

A clinically limiting feature of currently-available nicotine gum is its slow rate of nicotine delivery and consequently slow onset of therapeutic effects. Previous research suggested that a nicotine hydrogen tartrate gum (NHTG1) that delivered nicotine more rapidly provided more effective craving relief. A subsequent gum formulation (NTHG2) was developed to further increase speed of delivery.

Objective

Compare the plasma nicotine absorption and clinical tolerability of NHTG2 to NHTG1 and Nicorette® FreshMint™.

Methods

A single-dose, randomized, crossover study evaluated the early kinetics of nicotine absorption and tolerability of 4 mg NHTG2 compared to NHTG1 and Nicorette.

Results

NHTG2 gum reached higher C_max (p = 0.059 versus Nicorette; p = 0.006 versus NHTG1) and delivered significantly more nicotine than Nicorette or NHTG1 within the first 10-30 min of chewing (AUCs_{0-10, 0-30}) and overall (AUC_0-180). NHT gums and Nicorette were well tolerated, with little difference in their AE profiles.

Conclusions

Study results indicate that NHTG2 gum provided more rapid uptake of nicotine in blood without notable decreases in tolerability. To the extent that rate of delivery and onset of therapeutic effects are related, these gums would be expected to provide more rapid therapeutic effects.     

Opium poppy monitoring with remote sensing in North Myanmar

Background

Myanmar has long been a focus of the international community as a major opium poppy cultivation region.

Method

This study used remote sensing technology and ground verification to monitor opium poppy cultivation for three opium poppy growth seasons in North Myanmar.

Results

The study found that opium poppy cultivation has remained high. In 2005-6, 2006-7 and 2007-8 growing seasons the total areas monitored were 52,482 km², 178,274 km² and 236,342 km² and the total cultivated area of opium poppy was 8959 ha, 18,606 ha and 22,300, respectively. This was significantly less than cultivation levels reported during the 1990s. The major cultivation regions were located in Shan State, producing 88% of total poppy cultivation in North Myanmar in 2007-8. The opium poppy was mainly cultivated in the interlocking regions controlled by the local armed forces in Shan State. The field survey noted that most households in this area were poor and poppy cultivation was a main source of income. There were also differences between our figures on poppy cultivation and those reported by United Nations Office on Drugs and Crime.

Conclusion

Our study shows that although the opium poppy cultivation in North Myanmar has reduced over recent years, it remains a major producer of opium and to which the international community needs to pay attention, especially in those areas controlled by local armed forces.     

Internet-based group contingency management to promote abstinence from cigarette smoking: a feasibility study

Background

In contingency management (CM) interventions, monetary consequences are contingent on evidence of drug abstinence. Typically, these consequences are contingent on individual performance. Consequences contingent on group performance may promote social support (e.g., praise).

Methods

Thus, to combine social support with the monetary incentives of CM, we integrated independent and interdependent group contingencies of reinforcement into an Internet-based intervention to promote smoking abstinence. Breath carbon monoxide (CO) measures were compared between treatment conditions and a baseline control condition. Thirteen participants were divided into 5 groups or “teams” (n = 2-3 per team). Each participant submitted video recordings of CO measurement twice daily via the Internet. Teammates could monitor each other's progress and communicate with one another through an online peer support forum. During a 4-day tapering condition, vouchers exchangeable for goods were contingent on gradual reductions in breath CO. During a 10-day abstinence induction condition, vouchers were contingent on abstinence (CO ≤ 4 ppm). In both treatment conditions, concurrent independent and interdependent group contingencies were arranged (i.e., a mixed contingency arrangement).

Results

Less than 1% of CO samples submitted during baseline were ≤ 4 ppm, compared to 57% submitted during abstinence induction. Sixty-five percent of participants’ comments on the online peer support forum were rated as positive by independent observers. Participants rated the intervention favorably on a treatment acceptability questionnaire.

Conclusion

The results suggest that the intervention is feasible and acceptable for promoting abstinence from cigarette smoking.     

Cerebral edema induced in mice by a convulsive dose of soman. Evaluation through diffusion-weighted magnetic resonance imaging and histology

Purpose

In the present study, diffusion-weighted magnetic resonance imaging (DW-MRI) and histology were used to assess cerebral edema and lesions in mice intoxicated by a convulsive dose of soman, an organophosphate compound acting as an irreversible cholinesterase inhibitor.

Methods

Three hours and 24 h after the intoxication with soman (172 μg/kg), the mice were anesthetized with an isoflurane/N₂O mixture and their brain examined with DW-MRI. After the imaging sessions, the mice were sacrificed for histological analysis of their brain.

Results

A decrease in the apparent diffusion coefficient (ADC) was detected as soon as 3 h after the intoxication and was found strongly enhanced at 24 h. A correlation was obtained between the ADC change and the severity of the overall brain damage (edema and cellular degeneration): the more severe the damage, the stronger the ADC drop. Anesthesia was shown to interrupt soman-induced seizures and to attenuate edema and cell change in certain sensitive brain areas. Finally, brain water content was assessed using the traditional dry/wet weight method. A significant increase of brain water was observed following the intoxication.

Conclusions

The ADC decrease observed in the present study suggests that brain edema in soman poisoning is mainly intracellular and cytotoxic. Since entry of water into the brain was also evidenced, this type of edema is certainly mixed with others (vasogenic, hydrostatic, osmotic). The present study confirms the potential of DW-MRI as a non-invasive tool for monitoring the acute neuropathological consequences (edema and neurodegeneration) of soman-induced seizures.