Co-abuse of amphetamine and alcohol harms kidney and liver.

The prevalence of alcohol use disorder was found 75% higher among amphetamine dependent patients. Alcohol and amphetamine alone have nephrotoxicity and hepatoxicity. But, the degree of risk with coabuse of alcohol and amphetamine is unknown. The objective of this study was to assess toxic effects of amphetamine-alcohol co-abuse on the liver and kidney. he present study was a cross-sectional study conducted et al. Amal Hospital for Mental Health, Qassim region, KSA and include one hundred participants. Seventy-five participants were patients hospitalized for the treatment of abuse, and twenty-five participants, were healthy voluntaries, have no history of abuse. An experienced psychiatrist conducted patient interviews and assessed the patients using the DSM-5 criteria. The data from healthy participants were considered as a control. The abuse group was paired with the control group by age and lifestyle. Participants were split into: Group I: Control group (n = 25); Group II: Amphetamine (AMP) abuser group (n = 25); Group III: Alcohol abuser group (n = 25) and Group IV: Combined drug abuser group (AMP and alcohol) (n = 25). The socio-demographic data was collected. Complete medical examination, Body Mass Index and samples of blood and urine were collected from all participants for analytical tests; determination of alcohol and AMP levels, kidney functions and liver functions. The mean BMI values in groups II, III, and IV showed no significant change from the control group. The serum level of albumin and alkaline phosphatase showed significant decrease in all abuser groups. While, alanine transaminase (ALT), Aspartate transaminase (AST) and osteopontin levels showed significant increase in all abuser groups. Fasting blood sugar values showed significant increase in alcohol abusers. On the other hand, it revealed no significant change in AMP and combined groups. The mean values of urea showed no significant change in AMP and alcohol abusers and significant increase in combined drug abuser group. The serum creatinine and all abuser groups showed significant increase in Cystatin C. The alteration in the most of studied biochemical parameters were more than two folds in combined group compared with that of AMP or alcohol groups. Study reveals synergistic liver and kidney toxicity. Amphetamine-alcohol co-abuse significantly heightens kidney and liver toxicity.

Association Between Inflammatory Cytokines, Executive Function, and Substance Use in Patients With Opioid Use Disorder and Amphetamine-Type Stimulants Use Disorder.

BACKGROUND: Long-term opioid and amphetamine-type stimulants (ATS) abuse may affect immunological function and impair executive function. We aimed to determine whether biomarkers of inflammation and executive function were associated with substance use in individuals with opioid use disorder (OUD) and ATS use disorder (ATSUD). The interactions between these biomarkers were also explored. METHODS: We assessed plasma cytokines [tumor necrosis factor (TNF)-α, C-reactive protein (CRP), interleukin (IL)-8, IL-6, transforming growth factor (TGF)-ß1, brain-derived neurotrophic factor (BDNF), and executive function in terms of the Wisconsin Card Sorting Test (WCST) and Continuous Performance Test (CPT) in OUD and ATSUD patients and healthy controls (HC). OUD and ATSUD patients were followed for 12 weeks, and their urine morphine and amphetamine tests, cytokine levels, and executive function were repeatedly measured. RESULTS: We enrolled 483 patients and 145 HC. Plasma TNF-α, CRP, IL-8, IL-6, and BDNF levels and most subscale scores on the WCST and CPT significantly differed between OUD and ATSUD patients and HC. Increased TNF-α levels and more perseveration error on the WCST were significantly associated with more urine drug-positive results and less abstinence. Plasma IL-6 and CRP levels were significantly negatively correlated with WCST and CPT performance. CONCLUSION: OUD and ATSUD patients had more inflammation and worse executive function than HC. Inflammatory markers and WCST performance were associated with their urinary drug results, and higher inflammation was associated with poor executive function. Studies on regulating the inflammatory process and enhancing executive function in OUD and ATSUD are warranted.

A Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Efficacy and Safety of AR19, a Manipulation-Resistant Formulation of Amphetamine Sulfate, in Adults With Attention-Deficit/Hyperactivity Disorder.

Objective: To assess the efficacy and safety of AR19 in the treatment of attention-deficit/hyperactivity disorder (ADHD) diagnosed by DSM-5 criteria in adults from 18 through 55 years of age. AR19 is a pellets-in-capsule, immediate-release amphetamine sulfate investigational formulation with physical and chemical barriers designed to resist manipulation to deter snorting, smoking, and intravenous injection.Methods: This randomized, double-blind, placebo-controlled, fixed-dose, forced titration, multicenter trial investigated the safety and efficacy of AR19 from September 2018 to April 2019. Study participants were randomized and titrated to 20 mg or 40 mg AR19 daily or placebo. Study medication was dosed once in the morning and again 4 to 6 hours later for a period of 5 weeks. The primary efficacy measure was the total score on the Adult ADHD Investigator Symptom Rating Scale (AISRS).Results: Participants (N = 320) were randomized and received at least 1 dose of study medication. Demographics and baseline characteristics were similar across treatment groups. The least squares mean treatment differences versus placebo (97.5% CI) were -7.2 (-11.3 to -3.1) for the AR19 20-mg group and -7.3 (-11.4 to -3.2) for the AR19 40-mg group (each P < .001). The most common treatment-emergent adverse events occurring in participants in the AR19 treatment groups were insomnia, dry mouth, decreased appetite, palpitations, headache, and tachycardia and are consistent with the known safety profile of amphetamine sulfate.Conclusions: AR19 demonstrated efficacy on all endpoints and was generally well tolerated, supporting the efficacy and safety of AR19 20 mg and 40 mg in adults with ADHD.Trial Registration: ClinicalTrials.gov Identifier: NCT03659929.

Prevalence of Amphetamine-Type Stimulant Use and Related Factors among Methadone Maintenance Patients in Ho Chi Minh City Vietnam: A Cross-Sectional Study.

The objective of this study was to determine the prevalence of amphetamine-type stimulant use and associated factors among methadone maintenance treatment (MMT) patients. In 2018, a cross-sectional study was conducted on 967 MMT patients at two methadone clinics in Ho Chi Minh City that serve Vietnamese patients. Amphetamine-type stimulant use was assessed by rapid urine test and face-to-face interview using the Alcohol, Smoking, Substance Involvement Screening Test (ASSIST) tool. The prevalence of amphetamine-type stimulant use assessed by urine test was 25.4%. According to ASSIST, the prevalence of moderate and high risk amphetamine-type stimulant use was 15.5% and 1.1%, respectively. Amphetamine-type stimulant use and hazardous use were more prevalent in younger patients, having a part-time job, drug injection, having a lower score of self-health assessment, treated with a higher dose of methadone and missing methadone dose in the past 3 months. By contrast, patients who were HIV positive were less likely to use amphetamine-type stimulants. Cannabis and heroin use were significantly associated with amphetamine-type stimulant use (OR = 1.46; 95% CI: 1.38-8.67; and OR = 1.50; CI: 1.04-2.18, respectively) and hazardous use (OR = 4.07; CI: 1.67-9.92; and OR = 2.38; CI: 1.56-3.63, respectively). Screening and interventions are needed to cope with this issue on time, particularly in young patients, having drug injection and concurrent drugs user groups.

Pharmacologic treatment of attention deficit hyperactivity disorder in adults: A systematic review and network meta-analysis.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) affects approximately 3% of adults globally. Many pharmacologic treatments options exist, yet the comparative benefits and harms of individual treatments are largely unknown. We performed a systematic review and network meta-analysis to assess the relative effects of individual pharmacologic treatments for adults with ADHD. METHODS: We searched English-language published and grey literature sources for randomized clinical trials (RCTs) involving pharmacologic treatment of ADHD in adults (December 2018). The primary outcome was clinical response; secondary outcomes were quality of life, executive function, driving behaviour, withdrawals due to adverse events, treatment discontinuation, serious adverse events, hospitalization, cardiovascular adverse events, and emergency department visits. Data were pooled via pair-wise meta-analyses and Bayesian network meta-analyses. Risk of bias was assessed by use of Cochrane's Risk of Bias tool, and the certainty of the evidence was assessed by use of the GRADE framework. RESULTS: Eighty-one unique trials that reported at least one outcome of interest were included, most of which were at high or unclear risk of at least one important source of bias. Notably, only 5 RCTs were deemed at overall low risk of bias. Included pharmacotherapies were methylphenidate, atomoxetine, dexamfetamine, lisdexamfetamine, guanfacine, bupropion, mixed amphetamine salts, and modafinil. As a class, ADHD pharmacotherapy improved patient- and clinician-reported clinical response compared with placebo (range: 4 to 15 RCTs per outcome); however, these findings were not conserved when the analyses were restricted to studies at low risk of bias, and the certainty of the finding is very low. There were few differences among individual medications, although atomoxetine was associated with improved patient-reported clinical response and quality of life compared with placebo. There was no significant difference in the risk of serious adverse events or treatment discontinuation between ADHD pharmacotherapies and placebo; however, the proportion of participants who withdrew due to adverse events was significantly higher among participants who received any ADHD pharmacotherapy. Few RCTs reported on the occurrence of adverse events over a long treatment duration. CONCLUSIONS: Overall, despite a class effect of improving clinical response relative to placebo, there were few differences among the individual ADHD pharmacotherapies, and most studies were at risk of at least one important source of bias. Furthermore, the certainty of the evidence was very low to low for all outcomes, and there was limited reporting of long-term adverse events. As such, the choice between ADHD pharmacotherapies may depend on individual patient considerations, and future studies should assess the long-term effects of individual pharmacotherapies on patient-important outcomes, including quality of life, in robust blinded RCTs. REGISTRATION: PROSPERO no. CRD 42015026049.

Adolescent drug exposure: A review of evidence for the development of persistent changes in brain function.

Over the past decade, many studies have indicated that adolescence is a critical period of brain development and maturation. The refinement and maturation of the central nervous system over this prolonged period, however, makes the adolescent brain highly susceptible to perturbations from acute and chronic drug exposure. Here we review the preclinical literature addressing the long-term consequences of adolescent exposure to common recreational drugs and drugs-of-abuse. These studies on adolescent exposure to alcohol, nicotine, opioids, cannabinoids and psychostimulant drugs, such as cocaine and amphetamine, reveal a variety of long-lasting behavioral and neurobiological consequences. These agents can affect development of the prefrontal cortex and mesolimbic dopamine pathways and modify the reward systems, socio-emotional processing and cognition. Other consequences include disruption in working memory, anxiety disorders and an increased risk of subsequent drug abuse in adult life. Although preventive and control policies are a valuable approach to reduce the detrimental effects of drugs-of-abuse on the adolescent brain, a more profound understanding of their neurobiological impact can lead to improved strategies for the treatment and attenuation of the detrimental neuropsychiatric sequelae.

Critical View on the Usage of Ribavirin in Already Existing Psychostimulant-Use Disorder.

Substance-use disorder represents a frequently hidden non-communicable chronic disease. Patients with intravenous drug addiction are at high risk of direct exposure to a variety of viral infections and are considered to be the largest subpopulation infected with the hepatitis C virus. Ribavirin is a synthetic nucleoside analog that has been used as an integral component of hepatitis C therapy. However, ribavirin medication is quite often associated with pronounced psychiatric adverse effects. It is not well understood to what extent ribavirin per se contributes to changes in drug-related neurobehavioral disturbances, especially in the case of psychostimulant drugs, such as amphetamine. It is now well-known that repeated amphetamine usage produces psychosis in humans and behavioral sensitization in animals. On the other hand, ribavirin has an affinity for adenosine A1 receptors that antagonistically modulate the activity of dopamine D1 receptors, which play a critical role in the development of behavioral sensitization. This review will focus on the current knowledge of neurochemical/ neurobiological changes that exist in the psychostimulant drug-addicted brain itself and the antipsychotic-like efficiency of adenosine agonists. Particular attention will be paid to the potential side effects of ribavirin therapy, and the opportunities and challenges related to its application in already existing psychostimulant-use disorder.

Construction and Analysis of Protein-Protein Interaction Network of Heroin Use Disorder.

Heroin use disorder (HUD) is a complex disease resulting from interactions among genetic and other factors (e.g., environmental factors). The mechanism of HUD development remains unknown. Newly developed network medicine tools provide a platform for exploring complex diseases at the system level. This study proposes that protein-protein interactions (PPIs), particularly those among proteins encoded by casual or susceptibility genes, are extremely crucial for HUD development. The giant component of our constructed PPI network comprised 111 nodes with 553 edges, including 16 proteins with large degree (k) or high betweenness centrality (BC), which were further identified as the backbone of the network. JUN with the largest degree was suggested to be central to the PPI network associated with HUD. Moreover, PCK1 with the highest BC and MAPK14 with the secondary largest degree and 9th highest BC might be involved in the development HUD and other substance diseases.

Longitudinal patterns of amphetamine use from adolescence to adulthood: A latent class analysis of a 20-year prospective study of Australians.

BACKGROUND: To examine the longitudinal patterns of amphetamine use over twenty years from adolescence to the mid-thirties; and identify adolescent antecedents of future problematic patterns of use. DESIGN: Ten-wave longitudinal study following participants from age 15 to age 35 in Victoria, Australia. Participants (N = 1755; 47% males) first enrolled in the Victoria Adolescent Health Cohort Study in 1992. MEASUREMENTS: Outcome: Self-reported frequency of amphetamine use. PREDICTORS: Gender, depression and anxiety, peer alcohol and tobacco use; self-reported alcohol, tobacco and cannabis use, self-reported adolescent antisocial behavior. FINDINGS: Three different longitudinal patterns were identified: Non-user (83.7%); Occasional user (14.5%); Regular user (1.8%). Among the two user patterns, amphetamine use was commonly initiated in late teenage years or early 20s, peaked at mid-20s, and declined substantially by mid-30s. Participants who used cannabis and had smoking peers during adolescence were at significantly more likely to become an occasional or regular user (p < .05). CONCLUSION: Regular cannabis use and peer tobacco use during adolescence were the two strongest predictors of a longitudinal pattern of regular amphetamine use in the mid-30s. This suggests that prevention programs could be implemented around or before mid-adolescence and interventions to reduce amphetamine harms focus on high-risk individuals in their 20s when amphetamine use was at its peak.

Khat (Catha edulis) and its oral health effects: An updated review.

Khat or qat (Catha edulis) is a plant that grows in East Africa and southern Arabia. The leaves and twigs of this small tree are chewed by several millions of people worldwide for their stimulating amphetamine-like effects. The reported prevalence of khat chewing in Europe and the USA is on the rise, especially with global migration. Long-term khat chewing has several detrimental general and oral health effects. The aim of the present study was to review the current literature regarding khat use and its association with oral and dental diseases, with particular emphasis on its link with oral keratotic white lesions and oral cancer. We searched the literature to identify all relevant articles. Studies showed that khat is associated with several oral and dental conditions, including keratotic white lesions, mucosal pigmentation, periodontal disease, tooth loss, plasma cell stomatitis, and xerostomia. There are limited data on the incidence of dental caries among khat chewers. The evidence that khat chewing is a risk factor for oral cancer is still weak, and is mainly based on anecdotal case reports and uncontrolled studies.

[Amphetamine abuse is a possible cause of pontine haemorrhage].

This is a case report of a 55-year-old male, who was admitted due to right-sided sensorimotor deficits and one-and-a-half syndrome He had snorted 5 g of amphetamine over 24 h two months prior to admission. He was normotensive on admission. A CT brain scan showed left pontine haemorrhage, but a CT angiogram showed no vascular malformations nor vessel beading, and a two-month follow-up MRI showed no vascular malformations nor tumours. To the best of our knowledge, this is the fifth published case of pontine haemorrhage, and the first published case of one-and-a-half syndrome related to amphetamine abuse.

Safety and efficacy of fenproporex for obesity treatment: a systematic review / Segurança e eficácia do fenproporex para tratamento da obesidade: revisão sistemática

ABSTRACT OBJECTIVE To evaluate clinical evidence on the safety and efficacy of fenproporex for treating obesity. METHODS MEDLINE, LILACS and Cochrane Controlled Trials Register were searched as well as references cited by articles and relevant documents. Two authors independently assessed the studies for inclusion and regarding risk of bias, collected data, and accuracy. Eligible studies were all those placebo-controlled that provided data on the efficacy and safety of Fenproporex to treat obesity. RESULTS Only four controlled studies met the inclusion criteria. One randomized, placebo-controlled trial on Fenproporex was found on electronic databases. Three placebo-controlled studies (in non-indexed journals) were identified by hand-searching. Patients with cardiovascular and other comorbidities were excluded in all studies. Trials lasted from 40 to 364 days and doses ranged from 20 to 33.6 mg/d. All controlled studies found that weight loss among Fenproporex-treated patients was greater than that produced by the placebo, but drug effect was modest. Fenproporex produced additional weight reductions of 4.7 kg (one year), 3.8 kg (six months) and 1.55 kg (two months) in average, in relation to diet and exercise only (three trials). Insomnia, irritability, and anxiety were the most frequently reported side effects in the four studies. CONCLUSIONS There is a paucity of randomized, placebo-controlled trials on Fenproporex and those identified here present major methodological flaws. These studies suggest that Fenproporex is modestly effective in promoting weight loss. Nonetheless, they failed to provide evidence that it reduces obesity-associated morbidity and mortality. Data from these studies are insufficient to determine the risk-benefit profile of Fenproporex. Abuse potential and amphetamine-like adverse effects are causes for concern.

RESUMO OBJETIVO Avaliar a evidência clínica de segurança e eficácia do Fenproporex para tratamento da obesidade. MÉTODOS Pesquisamos publicações em qualquer idioma nas bases Medline, Lilacs Cochrane Controlled Trials Register e também referências citadas por artigos e documentos relevantes. Dois autores avaliaram independentemente os estudos para inclusão e quanto ao risco de viés, dados coletados e precisão. Foram elegíveis estudos controlados com placebo que forneceram dados sobre a eficácia e segurança do Fenproporex para tratar a obesidade. RESULTADOS Apenas quatro estudos controlados preencheram critérios de inclusão. Um estudo placebo-controlado aleatorizado do Fenproporex foi encontrado nas bases eletrônicas. Três estudos controlados (em periódicos não indexados) foram identificados por buscas manuais. Pacientes com comorbidades (cardiovasculares ou outras) foram excluídos em todos os estudos. A duração dos estudos foi de 40 a 364 dias, com doses de 20 a 33,6 mg/d. Todos os estudos controlados encontraram maior perda de peso entre pacientes tratados com Fenproporex, comparados aos que receberam placebo, mas o efeito foi modesto. O Fenproporex causou reduções adicionais de peso de 4,7 kg (após um ano), 3,8 kg (após seis meses) e 1,55 kg (após dois meses), em média, em relação à dieta e exercício apenas (três ensaios). Insônia, irritabilidade e ansiedade foram os eventos colaterais mais frequentes nos quatro estudos. CONCLUSÕES Ensaios clínicos placebo-controlado aleatorizado do Fenproporex são escassos e os estudos controlados identificados apresentam importantes falhas metodológicas. Esses estudos sugerem que o Fenproporex é modestamente eficaz em promover perda de peso. Entretanto, eles não fornecem evidências de que o Fenproporex atenua a morbidade e mortalidade associada à obesidade. Esses estudos são insuficientes para avaliar o perfil risco-benefício do Fenproporex. Potencial de abuso e efeitos adversos do tipo anfetamínico são motivos de preocupação.

N-acetylcysteine prevents increased amphetamine sensitivity in social isolation-reared mice.

Treating individuals at risk to develop schizophrenia may be strategic to delay or prevent transition to psychosis. We verified the effects of N-acetylcysteine (NAC) in a neurodevelopmental model of schizophrenia. C57 mice were reared in isolation or social groups and treated with NAC from postnatal day 42-70; the locomotor response to amphetamine was assessed at postnatal day 81. NAC treatment in isolated mice prevented the hypersensitivity to amphetamine, suggesting neuroprotection relevant to striatal dopamine. Considering its safety and tolerability profile, complementary studies are warranted to further evaluate the usefulness of NAC to prevent conversion to schizophrenia in at-risk individuals.

Drugs induced pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a rare disorder characterized by progressive obliteration of the pulmonary microvasculature, resulting in elevated pulmonary vascular resistance and premature death. According to the current classification, PAH can be associated with exposure to certain drugs or toxins, particularly appetite suppressant drugs, such as aminorex, fenfluramine derivatives and benfluorex. These drugs have been confirmed to be risk factors for PAH and were withdrawn from the market. The supposed mechanism is an increase in serotonin levels, which was demonstrated to act as a growth factor for the pulmonary arterial smooth muscle cells. Amphetamines, phentermine and mazindol were less frequently used but are also considered as possible risk factors for PAH. Dasatinib, a dual Src/Abl kinase inhibitor, used in the treatment of chronic myelogenous leukaemia was associated with cases of severe PAH, in part reversible after its withdrawal. Recently several studies raised the potential endothelial dysfunction that could be induced by interferon, and few cases of PAH have been reported with interferon therapy. Other possible risk factors for PAH include: nasal decongestants, like phenylpropanolamine, dietary supplement - L-Tryptophan, selective serotonin reuptake inhibitors, pergolide and other drugs that could act on 5HT2B receptors. Interestingly, PAH remains a rare complication of these drugs, suggesting possible individual susceptibility and further studies are needed to identify patients at risk of drugs induced PAH.

Uso de anfetaminas por motoristas de caminhão em rodovias do Estado de São Paulo: um risco à ocorrência de acidentes de trânsito? / Amphetamine use by truck drivers on highways of Sao Paulo State: a risk for the occurrence of traffic accidents?

The use of amphetamines in Brazil is common among truck drivers, which may be an important factor in the occurrence of traffic accidents. This article seeks to estimate the prevalence of amphetamine use among truck drivers. Drivers (N = 134) were stopped on two different highways in Sao Paulo state and they were asked to answer a questionnaire and provide a urine sample for toxicological analysis. All data were analyzed on Stata 8.0. All participants were males with low levels of schooling, whose mean age was 40.8 years. The presence of amphetamines was detected in 10.8% of all urine samples collected, being commonly justified in order to make truck drivers able to maintain their state of awareness. Amphetamine use was detected among truck drivers on Sao Paulo highways. The problem is that when the stimulant effects wear off, sleepiness due to sleep deprivation reduces concentration and good driver performance, making drivers vulnerable to traffic accidents and the related effects.

No Brasil, é comum o uso de anfetaminas por motoristas de caminhão, o que pode culminar na ocorrência de acidentes de trânsito. O objetivo deste artigo é estimar a prevalência do uso de anfetaminas entre caminhoneiros. Motoristas (N = 134) foram abordados em duas rodovias do Estado de São Paulo e solicitados a responder um questionário, assim como a fornecer uma amostra de urina para realização de análises toxicológicas. Todos os dados foram analisados em Stata 8.0. Todos os participantes eram do sexo masculino, de idade média de 40,8 anos e de baixa escolaridade. A presença de anfetaminas foi detectada em 10,8% das amostras de urina, cujo uso foi justificado para manter a vigília durante o trabalho. O uso de anfetaminas foi detectado entre caminhoneiros em rodovias de São Paulo. Cessado o efeito estimulante, a sonolência advinda de uma possível privação de sono diminui a atenção e o bom desempenho na direção, predispondo o condutor aos acidentes de trânsito e seus custos relacionados.

Is nicotine protective against Parkinson's disease? An experimental analysis.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) and its projections. Reports show a lower incidence of PD in smokers compared to nonsmokers. Nicotine reduce motor symptoms of patients already diagnosed with PD. However, the mechanisms underlying the effects of nicotine in the dopamine (DA) depleted striatum remain elusive. This study evaluates the effects of chronic nicotine administration on PD motor symptoms in an attempt to mimic the chronic self-administration of nicotine in smokers. To achieve this, we used the 6-OHDA hemiparkinson rat model evaluating the amphetamine/apomorphine induced circling behavior, in rats whose daily water intake included nicotine. We found that chronic nicotine reduced amphetamine (AMPH) induced circling behavior by 40%, whereas apomorphine (APO) increased this behavior by 230%. High-performance liquid chromatography (HPLC) revealed that AMPH produced a 50% decrease of DA release in the intact hemisphere, while on the striatum of the lesioned side, receptor binding assays showed an increased affinity to D1 receptors and a concurrent decrease in D2 receptors. c-Fos activity showed through double labeling, that cell types involved in nicotine action were low threshold (LTS) and fast spiking (FS) inter-neurons, which increased in the DA-depleted striatum. We also observed an increase in the activity of D1 medium spiny neurons (D1 MSN), a striatal population with a major role in motor control. Our results show that chronic nicotine does not specifically protect against degeneration, but rather modifies DA receptor dynamics, suggesting that it could be used as a therapeutic element in PD pathology.

The role of endogenous neurotensin in psychostimulant-induced disruption of prepulse inhibition and locomotion.

The neuropeptide neurotensin (NT) is closely associated with dopaminergic and glutamatergic systems in the rat brain. Central injection of NT into the nucleus accumbens (NAcc) or peripheral administration of NT receptor agonists, reduces many of the behavioral effects of psychostimulants. However, the role of endogenous NT in the behavioral effects of psychostimulants (e.g. DA agonists and NMDA receptor antagonists) remains unclear. Using a NTR antagonist, SR142948A, the current studies were designed to examine the role of endogenous NT in DA receptor agonist- and NMDA receptor antagonist-induced disruption of prepulse inhibition of the acoustic startle response (PPI), locomotor hyperactivity and brain-region specific c-fos mRNA expression. Adult male rats received a single i.p. injection of SR142948A or vehicle followed by D-amphetamine, apomorphine or dizocilpine challenge. SR142948A had no effect on baseline PPI, but dose-dependently attenuated d-amphetamine- and dizocilpine-induced PPI disruption and enhanced apomorphine-induced PPI disruption. SR142948A did not significantly affect either baseline locomotor activity or stimulant-induced hyperlocomotion. Systemic SR142948A administration prevented c-fos mRNA induction in mesolimbic terminal fields (prefrontal cortex, lateral septum, NAcc, ventral subiculum) induced by all three psychostimulants implicating the VTA as the site for NT modulation of stimulant-induced PPI disruption. Further characterization of the NT system may be valuable to find clinical useful compounds for schizophrenia and drug addiction.

Amphetamine-induced dyskinesia in the transplanted hemi-Parkinsonian mouse.

The transplantation of dopamine-rich tissue into the putamen of patients with Parkinson's disease shows much potential for use as a therapeutic strategy. However, a number of grafted individuals subsequently developed a set of abnormal involuntary movements (AIMs), unrelated to the dyskinesia caused by L-DOPA treatment, which have been termed graft-induced dyskinesia. Given the small number of patients, pre-clinical modeling of graft-induced dyskinesia in animal models will be critical to determine the underlying mechanisms and amelioration potential of this technique. Here we show that abnormal involuntary movements of the limbs, trunk and face can be observed in transplanted hemi-parkinsonian mice following amphetamine administration, similar to those previously described to model graft-induced dyskinesias in rats. C57Bl6 and CD1 mice were first rendered hemi-parkinsonian with 6-hydroxydopamine, treated with L-DOPA for 21 days until dyskinetic, and then transplanted with a single cell suspension of embryonic ventral mesencephalon (VM E12.5) tissue from corresponding strains into the denervated striatum. At 16 weeks post-transplantation, a single injection of amphetamine-elicited dyskinesia in a subgroup of mice of both strains, behavioural pattern not observed pre-transplantation. The number of surviving dopaminergic cells in the graft did not differ between those that developed AIMs and those that did not. The movements were phenotypically comparable to those seen in the rat model and parallels can be drawn to the human form of the movements, although the mouse model maybe less reproducible than the rat equivalent. This mouse model will facilitate assessment of graft-induced dyskinesia with mouse-derived stem cell lines and exploration of mechanisms using transgenic mice in future studies.

Chemical cardiomyopathies: the negative effects of medications and nonprescribed drugs on the heart.

The heart is a target of injury for many chemical compounds, both medically prescribed and not medically prescribed. Pathophysiologic mechanisms underlying the development of chemical-induced cardiomyopathies vary depending on the inciting agent, including direct toxic effects, neurohormonal activation, altered calcium homeostasis, and oxidative stress. Numerous chemicals and drugs are implicated in cardiomyopathy. This article discusses examples of medication and nonprescribed drug-induced cardiomyopathies and reviews their pathophysiologic mechanisms.