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—In terms of mobile apps, mHealth technology might enhance public health. However, despite the development of hundreds of health-related mobile applications, few studies have studied their relationship to psychological constructs. This study aimed to evaluate the association between the intensity of mHealth app use and nutrition knowledge, healthy-eating self-efficacy, and positive body image among Jordanian students and to measure their levels. In the first semester of the academic year 2022-2023, a structured, self-administered web-based questionnaire containing valid and reliable measures (i.e., positive body image scale, healthy eating self-efficacy, general nutrition knowledge questionnaire, and the adopted intensity use of mHealth apps scale) was administered to 414 undergraduates. The findings reported that their usage of mHealth-related mobile applications was low, as they had inadequate nutrition knowledge, low healthy-eating self-efficacy, and a moderate positive body image. The Pearson correlation analysis revealed a significant and positive correlation between the degree of usage of health-related mobile applications and nutrition knowledge, healthy eating self-efficacy, and positive body image (p

This study aimed to explore the meaning of life among Syrian adolescent refugees enrolled in public schools in Jordan. In particular, it investigated the relationship between the meaning of life and unhealthy behaviors among Syrian adolescent refugees enrolled in public schools in Jordan. The sample comprises 225 Syrian adolescent refugees (104 males and 121 females). The clustering random sampling method was used. Moreover, a scale for exploring the meaning of life was developed to meet the study’s goals. A scale for exploring unhealthy behaviors was also developed. The psychometric characteristics of those scales explored were validity and reliability. The respondents’ meaning of life level is moderate, and the extent of practicing unhealthy behaviors is moderate. There is a negative statistically significant relationship between the meaning of life and unhealthy behaviors among the respondents. In addition, there is a significant difference between the respondents’ meaning of life levels, which can be attributed to gender in favor for females. Conversely, there is a significant difference between the respondents’ extent of practicing unhealthy behaviors, which can be attributed to gender for the favor of males. As a result, the researchers recommend exerting effort to reduce the extent of practicing unhealthy behaviors by Syrian adolescent refugees. Furthermore, they recommend exerting effort to improve the meaning of life among them.

Background: Many meta-analyses studied the association between vitamin D receptor (VDR) gene polymorphism and type 1 diabetes (T1DM) susceptibility. Objective: This study was designed to assess the role of VDR gene (FOK-I) polymorphisms in type 1 diabetic children from Zagazig University Hospitals in Egypt. Patients and Method: In this case-control study, the genotypes of VDR gene (FOK-I) polymorphisms were assessed in 180 type 1 diabetic children and 120 healthy matched age controls by PCR-RFLP analysis. Results: A high statistical difference between patient and control regarding VDR gene (FOK-I) polymorphisms, where 44% of the patient group had heterozygous genotype (AG) compared to 8.3% in the control group. AG genotype has almost a higher risk nine times odds ratio (OR) = 8.8 than AA genotype in diabetic patients. There was a significant increase in the G allele in the patient group. Moreover, a significant association between (FOK-I) polymorphisms and T1DM complications was also observed. Conclusion: (AG) genotype of VDR gene (FOK-I) polymorphisms could be a risk factor for T1DM complications. So, VDR gene (FOK-I) polymorphisms should be performed with other genetic studies for early prediction, detection and prevention of microvascular complications of T1DM that adversely affect health-related quality of life of Egyptian children and burden the primary care units.

The study aimed to reveal the level of intellectual security and its relationship to life satisfaction among students at the University of Mutah, Jordan. A correlation approach was used. To achieve those objectives, intellectual security and life satisfaction scales were developed, and their psychometric characteristics were verified. The sample consisted of 297 students (146 males, 151 females). The study results showed moderate levels of intellectual security and life satisfaction among the students, and that there is a relationship between intellectual security, social-life satisfaction, and personal-life satisfaction. Intellectual security did not differ between genders, and the life satisfaction of the females was better than that of the males. Intellectual security and life satisfaction did not differ by academic year. The study recommends paying attention to students struggling academically and providing therapeutic programmes to help them, and especially the males, in the development of life satisfaction.

This research paper aimed to identify the level of psychological hardiness, the level of death anxiety, and the level of existential vacuum among the elderly, also the role of the predictive ability of death anxiety and existential vacuum in the psychological hardiness of the elderly at the governorates of Tafilyah and Ma’an in light of the Corona pandemic in Jordan. The descriptive-analytical approach was utilized. sample consists (500) elderly, that were selected by a simple random approach. Then the needed statistical measure was operated to achieve the required results. The results indicated a low level of psychological hardiness, a high level of death anxiety, and an existential vacuum in the elderly. The results show a suitable predictive ability for each of death anxiety and the existential vacuum in reducing psychological hardiness. The research paper recommended the necessity of rehabilitating the elderly in Jordan regarding the mental and psychological aspects.

This study aimed to reveal the level of happiness and psychosocial Adjustment among teenagers living in protection and care houses in Amman, to know the possible relationships between these factors and the possible differences according to brothers exist and age. By using a quantitative approach, 82 Teenager were selected from the teenagers their ages are between (12-16) years, to achieve the objectives of the study, the study measures were developed and the indications of validity and reliability of the two scales were verified and applied to the study sample. Their levels of happiness and psychosocial Adjustment were found to be moderate, with a statistically significant positive correlation between the variables. Also, the results revealed a statistically significant difference in the level of both happiness and psychosocial Adjustment according to brothers exist in favor to who has brothers and according to age in favor of less than 15 years.

The purpose of this study is to reveal the level of TechnoWellness (TW), Happiness and Optimism among bachelor’s degree students of the University of Jordan, and discover if there is a relationship between them, also to discover the difference according to gender and faculty. Participants selected in stratified random sampling consisted of (450) students registered for bachelor’s degree in 2017/2018 year at the University of Jordan. The results of this study show that the level of TW and Happiness among students came in average level, while the level of Optimism was “high”. There is statistically significant positive correlation between the variables, Also the results show that there is statistically significant difference according to gender variable on the TW to male and doesn’t reveal statistically significant due to gender on the Happiness or Optimism, finally the result didn’t reveal statistically significant differences due to faculty on any of the three variables.

The purpose of this study was to investigate the efficacy of a preventive counseling program for improving psychological hardiness (PsyH) and the positive use of social network sites (SNSs). The sample consisted of 30 students from Mu’tah University in Jordan who were randomly assigned into either an experimental group (15) or a control group (15). Two constructed scales - the PsyH scale and the Positive Use of SNSs scale - were administered to both groups pre-test and post-test, and a one-month follow-up measure was also administered to the experimental group. The findings revealed that the preventive counseling program significantly improved the level of PsyH and the positive use of SNSs and seemed to have sustained efficacy.

Background The localized monitoring of brain temperature is crucial to the understanding of the mechanisms underlying brain hyperthermia, such as that caused by stimulant drugs. Many animal studies investigating brain hyperthermia have utilized thermocouple electrodes for temperature measurement, however optical fiber sensors have proven to be an attractive alternative to conventional measurement techniques. Despite their advantages, optical fiber sensors in their current form have struggled to find effective use in studies involving free-moving animals. New method We have developed an improved optical fiber temperature probe and implantation method suitable for sensing in free-moving animals. By altering the structure of the probe, conventional guide cannulae can be used for stereotaxic implantation thus increasing ease-of-use and probe durability. Results The new probe structure was easily implanted and extremely durable both pre-experimentation and during sampling in vivo. Probe re-usability also allowed for increased experimental workflow. Rats administered MDMA showed pathological increases in brain temperature. Comparison with existing method(s) Thermocouples commonly used for temperature measurement in deep brain structures lack the advantages offered by optical fiber sensors. Unlike our improved design, previous optical fiber temperature probes were unable to be removed from the brains of rats without removing the dental cement affixing it to the skull. This made the probe susceptible to breakage and often resulted in the complete loss of the animal from the experiment. Conclusions Our fiber temperature probe and revised implantation technique can be easily employed in brain thermorecording using advantageous optical fiber sensors suitable for use in awake free-moving animals.

We report on the development of an optical fiber based probe for in vivo measurements of brain temperature. By using a thin layer of rare-earth doped tellurite glass on the tip of a silica optical fiber a durable probe, suitable for long-term in vivo measurements of temperature can be fabricated. The probe can be interrogated using a portable optical measurement setup, allowing for measurements to be performed outside of standard optical laboratories as no alignment of components is required. This setup is deployed to a medical research laboratory to show preliminary results on the use of these optical fibers for in vivo pre-clinical measurements of brain temperature. Refereed/Peer-reviewed

This work reports on the development of an optical fiber based probe for in vivo measurements of brain temperature. By utilizing a thin layer of rare-earth doped tellurite glass on the tip of a conventional silica optical fiber a robust probe, suitable for long-term in vivo measurements of temperature can be fabricated. This probe can be interrogated using a portable optical measurement setup, allowing for measurements to be performed outside of standard optical laboratories. Refereed/Peer-reviewed

International audience; This paper presents two approaches of observer based stabilization for Takagi-Sugeno (T-S) systems with immeasurable premise variables in continuous time case. These approaches are based on the description of the state estimation error by a T-S model. To design the observer based stabilization law, the concept of PDC (Parallel Distributed Compensation) is employed, the sufficient stabilization conditions are proved and expressed in the form of Linear Matrix Inequalities (LMI). The perform-ances of these approaches are tested by simulation for an illustrate example and a physical system representing a two-link robot.

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is associated with increases in core body temperature (T(C)) and depressive mood states in users. Flinders Sensitive Line (FSL) rats represent a rat model of depression originally bred from Sprague-Dawley (SD) rats. They are more sensitive to both muscarinic and serotonergic agonists and have altered thermoregulatory responses to various drugs. To examine the link between MDMA and depression, eight FSL and eight SD rats were administered saline and 5 and 7.5 mg/kg MDMA. Immediately following administration, rats were confined to an area with an ambient temperature (T(A)) of 30 ± 1°C for 30 minutes before being allowed access to a thermal gradient for four hours. The brains were removed one week after final dose of MDMA and concentrations of serotonin and dopamine were measured. Treatment with MDMA at both doses led to a higher T(C) in the FSL rats than the SD rats at high T(A) (P < 0.01). Fatalities due to hyperthermia occurred in the FSL rats after both doses, whereas all but one of the SD rats recovered well. Heart rate was also much higher after MDMA in the FSL rats throughout the experiments. The FSL rats showed significant decreases in all transmitters measured (P < 0.05). These differences between strains were not accounted for by altered blood or brain concentrations of MDMA. The results indicate that the FSL rats may be more susceptible to developing MDMA-induced hyperthermia and possible damage to the brain. These findings may be of importance to human users of MDMA who also have depression.

Methadone used for opioid dependence therapy is associated with increased pain sensitivity. This study aimed to investigate whether methadone administration lowers nociceptive threshold in adult male Sprague-Dawley (SD) rats, and if this threshold could be altered by the NMDA receptor antagonist memantine. Rats were implanted with osmotic pumps delivering 1 mg/kg/day methadone (n=6), or saline placebo (n=6) (0.51 μl/h). A separate cohort of rats received either methadone 1 mg/kg/day (n=8) or methadone 1 mg/kg/day with 20 mg/kg/day memantine (n=8). Nociception was measured by the Hargreave's paw withdrawal test. Baseline nociception was measured on day 0 prior to osmotic pump implantation and was measured daily for the following 21 days. Osmotic pumps were removed following nociceptive testing on day 14. Methadone only treated rats had a mean paw withdrawal latency significantly lower than the corresponding values for saline on days 8, 9, 10, 11, 12, 14, and 17 (P0.05). Paw withdrawal latency of rats treated with methadone co-administered with memantine did not differ significantly compared to methadone only (P>0.05). This demonstrates that methadone induces hyperalgesia in the SD rat yet this hyperalgesia resolves following discontinuation of methadone administration. Furthermore, memantine does not alter the development of methadone-induced hyperalgesia. Refereed/Peer-reviewed

3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") disrupts thermoregulation in rats and can lead to life-threatening hyperthermia in humans. MDMA administration can also lead to long-term neurotoxicity in animals and possibly humans.The purpose of the current study was to extend previous results on the acute effects of MDMA on behavioral thermoregulation to a repeated dosing regime, simulating regular weekend use of ecstasy, on measures of thermoregulation and heart rate (HR).Sprague-Dawley rats with telemetry implants were administered 40 micromol/kg MDMA on three consecutive days each week for 1 or 6 weeks before being confined to an elevated ambient temperature (TA) (HOT; 30+/-1 degrees C) or an area at room temperature (ROOM; 21.5+/-1.5 degrees C) for 30 min. After the final drug administration, rats were placed in a thermal gradient for 4 h to allow behavioral thermoregulation.HOT rats showed higher core temperature (TC), HR, and locomotor activity than ROOM rats during confinement to a set TA (P0.001). HR responses to MDMA over 6 weeks at both TAs progressively decreased with repeated dosing (P0.05). TC was significantly higher in both 6-week groups compared to the 1-week groups (P0.05) at the end of time in the gradient. Cortical concentrations of dihydroxyphenylacetic acid (DOPAC; P0.05) and 5-hydroxyindole acetic acid (5-HIAA; P0.001) decreased significantly irrespective of TA, while concentrations of dopamine and 5-HT did not change.Long-term treatment with MDMA resulted in apparent tolerance to the effects of the drug on HR, dysregulation of TC in thermal gradient, and depletion of cortical DOPAC and 5-HIAA.

The effects of the selective A 1 adenosine receptor agonist N 6 -cyclopentyladenosine (CPA) and the selective A 2a agonist 2-[p-(2-carboxethyl)phenylethyl-ethylamino]-5′-ethylcarboxamidoadenosine (CGS 21680) (each at 0.03, 0.1 and 0.3 mg/kg, SC) as well as the selective A 1 adenosine receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), non-selective antagonists 3-isobutyl-1-methylxanthine (IBMX), aminophylline, 3,7-dimethyl-1-propargyl-xanthine (DMPX) and 8(p-sulfophenyl)-theophylline (8-SPT) were investigated (each at 5, 10 and 30 mg/kg, SC) for their ability to alter the naloxone-precipitated opiate withdrawal syndrome in morphine-dependent rats. Effects of CPA and CGS 21680 on opiate withdrawal in the presence of aminophylline were also investigated. Both CPA and CGS 21680, caused a significant reduction in the incidence of body shakes, teeth chatter and paw shakes and decreased the amount of faecal matter produced. DPCPX, IBMX, DMPX, 8-SPT and aminophylline significantly increased the incidence of jumps and decreased the amount of faecal matter produced. The incidence of body shakes was significantly increased by DMPX, 8-SPT and IBMX. Neither CPA nor CGS 21680 were able to reverse the significant increase in the incidence of jumps caused by aminophylline. These data suggest that there is a role for endogenous adenosine in the modulation of the opiate abstinence syndrome and both A 1 and A 2a adenosine receptors are involved in this phenomenon.

A solid-phase extraction method and sensitive reversed phase high-performance liquid chromatography analysis with electrochemical detection of buprenorphine and its metabolite, norbuprenorphine, in rat plasma is described. Adequate separation of the compounds of interest was achieved on a Phenomenex C 18 reversed-phase column using a mobile phase comprising phosphate buffer: acetonitrile (75:25, pH 3.0) and 0.25 mM 1-octane-sulfonic acid, at a flow rate of 1 ml/min. Electrochemical detection was performed at a potential of 0.75 V and sensitivity of 2 nA. Buprenorphine and norbuprenorphine were extracted from plasma by solid-phase extraction technique using naltrindole as an internal standard (IS). Recoveries of buprenorphine and norbuprenorphine following the extraction method were high (70%–89%) over the concentration range used (25–100 ng/ml) and no endogenous substances in plasma interfered with any of the sample components. The retention times for norbuprenorphine, IS, and buprenorphine were 8, 12.5, and 30.5 min, respectively. The limits of detection of buprenorphine and norbuprenorphine in spiked plasma samples were 25 and 5 ng/ml, respectively. Using this method, buprenorphine was detected in rat plasma in animals acutely treated with the drug (5 mg/kg, s.c.).

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is associated with increases in core body temperature (T(C)) and depressive mood states in users. Flinders Sensitive Line (FSL) rats represent a rat model of depression originally bred from Sprague-Dawley (SD) rats. They are more sensitive to both muscarinic and serotonergic agonists and have altered thermoregulatory responses to various drugs. To examine the link between MDMA and depression, eight FSL and eight SD rats were administered saline and 5 and 7.5 mg/kg MDMA. Immediately following administration, rats were confined to an area with an ambient temperature (T(A)) of 30 ± 1°C for 30 minutes before being allowed access to a thermal gradient for four hours. The brains were removed one week after final dose of MDMA and concentrations of serotonin and dopamine were measured. Treatment with MDMA at both doses led to a higher T(C) in the FSL rats than the SD rats at high T(A) (P0.01). Fatalities due to hyperthermia occurred in the FSL rats after both doses, whereas all but one of the SD rats recovered well. Heart rate was also much higher after MDMA in the FSL rats throughout the experiments. The FSL rats showed significant decreases in all transmitters measured (P0.05). These differences between strains were not accounted for by altered blood or brain concentrations of MDMA. The results indicate that the FSL rats may be more susceptible to developing MDMA-induced hyperthermia and possible damage to the brain. These findings may be of importance to human users of MDMA who also have depression.

Cocaine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA, ecstasy), and para-methoxyamphetamine (PMA) disrupt normal thermoregulation in humans, with PMA being associated with more severe cases of hyperthermia. Harm minimization advice on how to prevent overheating depends on appropriate thermoregulatory behavior by drug users.The purpose of the current study was to establish dose-response relationships for the effects of a number of commonly used illicit stimulants and investigate the behavioral response to increased core temperature.Sprague-Dawley rats with telemetry implants were administered either saline or 4, 12, 26, 40 or 80 micromol/kg of cocaine, methamphetamine, MDMA, or PMA and confined to an ambient temperature of 30 degrees C for 30 min, before being able to choose their preferred temperature on a thermally graded runway (11-41 degrees C).The increased core temperature caused by administration of cocaine, methamphetamine, and MDMA treatment led to the animals seeking the cool end of the runway to correct their core temperature, although this did not occur in PMA-treated rats. The order of potency for increasing core temperature was methamphetaminePMA = MDMAcocaine. This differed to the slopes of the dose-response curves where MDMA and PMA showed the steepest slope for the doses used followed by methamphetamine then cocaine.These results suggest that behavioral aspects of thermoregulation are important in assessing the potential of individual drugs to cause harmful increases in core temperature.

Worldwide growth in p-methoxyamphetamine (PMA) usage amongst 'ecstasy' users indicates a proportionally greater incidence of acute toxicity compared to 3,4-methylenedioxymethamphetamine (MDMA). While longer-term use of MDMA appears to produce degeneration of 5-hydroxytryptamine (5-HT, serotonin) neurons, PMA effects are poorly understood. The aim of this study was to determine the effect of repeated PMA administration on two indices of 5-HT axonal degeneration, cortical brain 5-HT transporter (SERT) density and 5-HT/5-hydroxyindolacetic acid (5-HIAA) content. Treatment of male rats once daily for 4 days (10 or 20 mg/kg) with PMA or MDMA resulted in significant reductions (20 mg/kg: 53% and 23% of vehicle treatment respectively) in [(3)H]-paroxetine binding (SERT density) one week after final drug administration. When rats were housed at a higher ambient temperature (28 degrees C vs. 22 degrees C) for 6 h after dosing, no additive effect was seen for either drug. A more intensive dosing regimen (10 or 20 mg/kg twice daily for 4 days) was used to examine PMA/MDMA effects on cortical 5-HT content. Two weeks after MDMA treatment, significant reductions in cortical 5-HT content (20 mg/kg: 39% of vehicle treatment) were seen. However, PMA did not alter cortical 5-HT content, yet reduced cortical 5-HIAA content (20 mg/kg: 72% of vehicle treatment). These data suggest PMA has severe long-term implications clinically for alteration of 5-HT neurotransmission that may differ from MDMA, but may not necessarily be interpreted as a degeneration of 5-HT fibres.

3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") and para-methoxyamphetamine (PMA) are commonly used recreational drugs. PMA, often mistaken for MDMA, is reported to be more toxic in human use than MDMA. Both of these drugs have been shown to facilitate the release and prevent the reuptake of 5-hydroxytryptamine (5-HT, serotonin). PMA is also a potent inhibitor of monoamine oxidase type A (MAO-A), an enzyme responsible for the catabolism of 5-HT, and this characteristic may contribute to its increased toxicity. In humans, co-administration of MDMA with the reversible MAO-A inhibitor moclobemide has led to increased apparent toxicity with ensuing fatalities. In the present study, using microdialysis, we examined the effects of co-administration of MDMA and PMA with moclobemide on extracellular concentrations of 5-HT and 5-hydroxy indol acetic acid (5-HIAA) in the striatum of the rat. 5-HT-mediated effects on body temperature and behavior were also recorded. Rats were pretreated with saline or 20 mg/kg (i.p.) moclobemide and 60 min later injected with 10 mg/kg MDMA, PMA, or saline. Dialysate samples were collected every 30 min for 5 h and analyzed by HPLC-ED. Both MDMA and PMA produced significant increases in extracellular 5-HT concentrations (590% and 360%, respectively, P0.05). Rats treated with PMA and MDMA displayed significantly increased 5-HT-related behaviors (P0.05). Furthermore, only MDMA was capable of producing additional significant increases in 5-HT concentrations (980%, P0.05) when co-administered with moclobemide. These data suggest that co-administration of MDMA with moclobemide increases extracellular 5-HT and 5-HT-mediated behaviors and may cause increased 5-HT related toxicity similar to that reported with PMA.

Project Background The main MDMA-induced adverse effect is disruption of normal thermoregulation leading to life threatening hyperthermia which is exacerbated by high ambient temperature and linked to chronic neurotoxicity. Although the focus of the majority of research on MDMAinduced loss of thermoregulation has been on brain serotonergic and dopaminergic systems, results obtained from our recent studies suggest an association between microglial activation and MDMA-induced hyperthermia. We have demonstrated that pretreatment with minocycline, an antibiotic with glial attenuating properties, can significantly reduce the severity of MDMA-induced hyperthermia in rats. We have also demonstrated that minocycline’s ability to inhibit MDMA induced hyperthermia is time-dependent process and you need up to three days pre-treatment with minocycline to achieve maximum effects.

Hyperthermia is a key clinical outcome from recreational use of MDMA and is the leading cause of MDMA related hospital admissions as well as being linked to enhanced neurotoxicity [1, 2]. Animal models of ischemia which also display hyperthermia have shown an inflammatory process mediated by microglia and the release of the proinflammatory cytokine interleukin 1(IL-1 ) play a role in hyperthermicreactions [3]. Previous studies showed that microglia is prominently activated and IL-1 levels increased following MDMA administration [4], lending support to the hypothesis microglia play a role in MDMA induced hyperthermia. Minocycline is a tetracycline antibiotic with powerful anti-inflammatory properties, thought to be a result of its ability to attenuate glial activation [5]. This study examined whether preventing microglial activation through the administration of minocycline could limit or prevent the hyperthermia induced by MDMA.

The possibility that naloxone-precipitated opiate withdrawal behaviors varied qualitatively over the course of the year was investigated. The experiments were carried out at monthly intervals over a 2-year period using rats treated with a morphine-containing slow-release emulsion. The results obtained from these experiments were equivocal, neither providing support for seasonal variance in the expression of the opiate abstinence syndrome, nor showing a complete lack of time-related differences. Although some behavioral signs of opiate abstinence showed seasonally related alterations in frequency over one of the years, this was not consistent from one year to another. It was therefore concluded that no significant relationship between the severity of the abstinence syndrome and the time of the year in which the experiment carried out could be demonstrated.

This study was performed to measure absorption of morphine from the injection site following treatment of rats with slow-release emulsions formulated with morphine hydrochloride and morphine base. Samples of emulsion were collected from the injection site of halothane anesthetized animals at 24 and 48 h following emulsion treatment and concentrations of morphine remaining in the emulsion were analyzed using high-performance liquid chromatography (HPLC). In another group of morphine-treated rats, at times equivalent to collecting samples of emulsion, the intensity of naloxone-precipitated withdrawal behaviors was monitored. Both morphine base- and hydrochloride-containing emulsions induced a high degree of physical dependence in animals treated over 48 h. Release of morphine from emulsions containing morphine base was slower than that from the hydrochloride formulations. In the 24-h morphine base-treated animals, approximately 45% was absorbed from the injection site as opposed to 99% in the 24-h morphine hydrochloride-treated animals. These results suggest that morphine base containing emulsions provide a more sustained exposure to the opioid.

Samples of extracellular fluid from striatum and nucleus accumbens of anaesthetised rats undergoing opiate withdrawal were collected using microdialysis and then analysed for adenosine and its metabolites using high performance liquid chromatography (HPLC) and ultraviolet (UV) detection. Although the amount of adenosine present in the dialysate from either brain region was below the limit of detection by 90 min after probe placement, the metabolites could still be detected. Samples of dialysates collected from the nucleus accumbens contained significantly higher concentrations of hypoxanthine and inosine following naloxone challenge. The data are compatible with the hypothesis that endogenous adenosine might be involved in the expression of the opiate abstinence syndrome.