Exploring the feasibility of an anti-idiotypic cocaine vaccine: analysis of the specificity of anticocaine antibodies (Ab1) capable of inducing Ab2beta anti-idiotypic antibodies

Conventional vaccination with the cocaine molecule conjugated to a protein carrier is a new approach in the treatment of addiction. Experimentally, this strategy has been shown to alter the pharmacokinetics as well as the psychostimulant effect of a cocaine challenge. The purpose of this study was to investigate whether a more stable and less controversial molecule, an anti-idiotypic antibody, which mimics the configuration of the cocaine molecule (Ab2beta), could be successfully used instead of cocaine. Two cocaine conjugates that presented different areas of the cocaine molecule to the immune system were used to produce monoclonal antibodies specific for cocaine (Ab1). Several anti-idiotypic antibodies were then produced. Four were identified as Ab2beta, or internal images of the antigen; when injected into BALB/c mice, they elicited an anticocaine response. The anticocaine response elicited by one of the four Ab2beta (K1-4c) was sufficient to significantly reduce the level of cocaine that targeted the brain following cocaine challenge, compared with the level of cocaine found in the brain of control animals immunized with irrelevant antibody. In conclusion, the possibility of an anti-idiotypic vaccine seems to be worth pursuing.     

Emerging patterns of cocaine use and the epidemic of cocaine overdose deaths in Dade County, Florida

With the increasing use of cocaine in the United States, cocaine overdose deaths are being reported with increasing frequency. To describe patterns of cocaine use involved in cocaine overdose deaths, we reviewed the postmortem records from the Metropolitan Dade County Medical Examiner Department, Miami, Fla. We identified 239 cocaine overdose deaths from 1971 through 1987. During this period, the incidence of cocaine overdose deaths increased 20-fold, with the largest proportional increases occurring among persons aged older than 24 years, white persons, and men. The percentage of deaths that involved use of cocaine by nonparenteral routes, as well as newer and unknown preparations of cocaine (such as "crack" and "free-base" cocaine), increased. For example, the percentage of deaths that involved use of crack or free-base cocaine increased from 8% in 1981 to 20% in 1987. Persons who died after smoking crack or free-base cocaine had lower blood cocaine levels at autopsy (median level, 0.3 mg/L) than persons who died as a result of using cocaine hydrochloride (median level, 3.7 mg/L). Patterns of cocaine use involved in the epidemic of cocaine overdose deaths are changing. The data suggest that the newer preparations of cocaine, such as crack or free-base cocaine are playing an increasingly important role in this epidemic and that these preparations may be more toxic than cocaine hydrochloride.     

Therapeutic vaccines for substance dependence

Immunotherapies are under development as a new approach to the treatment of substance dependence. The drugs of abuse currently being tested using this new approach are nicotine, cocaine, phencyclidine and methamphetamine. In laboratory animal models, a range of immunotherapies, including vaccines, monoclonal antibodies and catalytic antibodies, have been shown to reduce drug seeking. In human clinical trials, cocaine and nicotine vaccines have been shown to induce antibody titers while producing few side effects. Studies in humans determining how these vaccines interact in combination with their target drug are underway. Overall, immunotherapy offers a range of potential treatment options: drug treatment, as well as the treatment of overdose, prevention of brain or cardiac toxicity and fetal protection in pregnant drug abusers.     

Therapeutic vaccines for substance dependence

Several immunotherapies are under development for nicotine, cocaine and phencyclidine and a cocaine vaccine has started human trials. These therapies promise a new approach to diseases that have had limited treatment success and tremendous morbidity. Both the cocaine and nicotine addiction immunotherapies have reduced 'relapse' to drug use in animal model systems. To date, the active cocaine vaccine has few side effects and induces considerable antibody titers after active immunization in humans. Studies with the monoclonal phencyclidine immunotherapy provide intriguing evidence of sustained protection for months after single-dose administration. Other immunotherapy may include treatment of drug overdose, prevention of brain or cardiac toxicity and protection of a fetus during pregnancy in a drug abuser.     

Neuropsychiatric effects of cocaine use disorders

Individuals who use cocaine report a variety of neuropsychiatric symptoms that are yet to be adequately targeted with treatment modalities. To address this problem requires an understanding of these symptoms and their neurobiological origins. Our paper reviewed the existing data on the neuropsychiatic implications of cocaine. We conducted a Medline search from 1984-2004 using terms, such as "cocaine", "cocaine addiction", "cocaine abuse", "cocaine neuropsychiatry" and "dual diagnosis". The search produced additional reference materials that were used in this review, although we focused on data that have likely clinical implications. The literature evidence suggested that, whereas acute cocaine overdose is potentially fatal, the ingestion of mild-to-moderate doses could result in fatal or nonfatal neuropsychiatric events. Also, chronic cocaine use may be associated with deficits in neurocognition, brain perfusion and brain activation patterns. Some of these deficits were unresolved with periods of abstinence ranging from 3-200 days. Taken together, these studies suggest the need for further investigations to fully characterize the neurobiological substrates of cocaine use disorders (CUDs) with the future possibility of more efficient treatment modalities.     

MicroRNAs与可卡因成瘾关系的研究进展

可卡因进入体内会导致海马、前额叶皮层、中脑腹侧被盖区及伏隔核等学习记忆相关脑区的多巴胺、谷氨酸、5-羟色胺(5-hydroxytryptamine,5-HT)等神经递质释放的异常变化,通过作用于相应的受体引发一系列分子事件:包括激活细胞内信号转导通路,改变神经营养因子、转录因子、即刻早期基因或染色体的结构等,并最终引起突触的可塑性,甚     

Association analysis of GRK3 gene promoter variants in cocaine abuse

The G protein-coupled receptor kinase 3 gene (GRK3) is a candidate gene for cocaine addiction because it is involved in the regulation of several neurotransmitter receptors, including the response to dopaminergic agonists such as methamphetamine and cocaine. We hypothesized that genetic variants in the GRK3 gene might be associated with an increased risk of cocaine addiction. To test this, we genotyped three variants located in 5' untranslated and promoter regions of the gene in a sample of 711 cocaine users and 862 healthy control individuals from Sao Paulo, Brazil. Genotypic, allelic and haplotypic analyses provided no evidence for an association between alleles at these polymorphisms and cocaine abuse in this sample. Population stratification was tested for and its effect corrected for, but this did not affect the association test results. In conclusion, our results do not support a major role for GRK3 gene promoter variants in cocaine addiction.     

Neonatal amygdala lesions: co-occurring impact on social/fear-related behavior and cocaine sensitization in adult rats

Neurodevelopmental abnormalities of temporal-limbic structures may underlie both adult psychiatric syndromes and increased addiction vulnerability, leading to high frequencies of "dual diagnosis" disorders. Although the amygdala is implicated in various mental disorders and drug addiction, no studies have explored the impact of early developmental damage to the amygdala on phenotypes relating to mental illness and addictions as co-occurring processes. We tested rats with neonatal amygdala lesions (NAML) vs. SHAM-operated controls in a battery of tests--novel field activity, elevated plus maze (EPM), and social interaction (SI) at baseline and after odor and restraint stress--followed by measures of cocaine sensitization (15 mg/kg vs. saline x 5 days + challenge session 2 weeks later) and remeasurement of SI. NAMLs showed increased novelty-related locomotion, less fear responding in the EPM, and resistance to predator-odor- but not to restraint-induced suppression of SI. NAMLs also had elevated cocaine sensitization profiles, and cocaine history differentially affected subsequent SI in NAMLs compared with SHAMs. NAMLs may provide models for understanding a shared neurobiological basis for and complex interactions among psychiatric symptoms, drug exposure history, and addiction vulnerability.     

Cocaine alters catalase activity in prefrontal cortex and striatum of mice

Catalase is one of the enzymes that convert hydrogen peroxide (H2O2) to H2O presenting a protective role against free radicals. In this study, catalase activity was determined in homogenates of striatum (ST) and prefrontal cortex (PFC) in order to examine the participation of oxidative stress (OS) on cocaine actions in mice brain. Male Swiss mice were injected (i.p.) with cocaine at low (10 and 30 mg/kg) and high doses (90 mg/kg), and observed for 1 h. After cocaine overdose (90 mg/kg) some animals presented only status epilepticus (SE) while others died after seizures. These animals were dissected and divided in two groups, SE and death. Catalase activity was also determined after pretreatment with the anticonvulsant drug, diazepam, alone or injected before cocaine 90 mg/kg, and after seizures induced by a high dose of bupropion, a known inhibitor of NE and DA reuptake used for comparison. Results showed a decrease in catalase activity of the PFC and ST after SE and death induced by cocaine and bupropion overdoses. Cocaine at low doses decreased the enzyme activity only in ST. Diazepam treatment alone and before cocaine overdose did not interfere with catalase activity. This reduction in catalase activity may reflect an increase in H2O2 content in PFC and ST. Previous data reports that H2O2 inhibits dopamine transporter activity, suggesting that the decrease in catalase activity may potentiate the toxic mechanism of drugs that inhibit monoamines reuptake. As far as we know, this is the first report showing an involvement of OS in the cocaine's central mechanism of action.     

Cocaethylene synthesis in Drosophila

Cocaethylene is an active cocaine metabolite that targets mammalian neural reward pathways and thus contributes to the reinforcing and addictive properties of ethanol and cocaine. Using gas chromatography-mass spectrometry, we find that fruit flies (Drosophila melanogaster) possess a cellular mechanism through which cocaine can be converted to cocaethylene, presumably via ethanol-sensitive enzymes. These findings illustrate the striking similarity of gene products in humans and flies, which might reflect a homologous role in the metabolic inactivation of cocaine. Further, this conservation of metabolic steps suggests that Drosophila can be used to study cellular, molecular and biochemical processes leading to polydrug abuse and addiction.     

Preclinical evidence for GABAB agonists as a pharmacotherapy for cocaine addiction

A variety of studies indicate that GABA(B) receptor agonists may be useful in the treatment of addictive disorders. This brief review summarizes self-administration studies in rats which show that baclofen and other GABA(B) agonists may have specific effects on the reinforcing effects of cocaine. Preliminary clinical data with baclofen have also been encouraging. The obstacles and issues related to the use of GABA drugs in addiction therapy are briefly addressed.     

Group II metabotropic glutamate receptors in the striatum of non-human primates: Dysregulation following chronic cocaine self-administration

A growing body of evidence has demonstrated a role for group II metabotropic glutamate receptors (mGluRs) in the reinforcing effects of cocaine. These receptors are important given their location in limbic-related areas, and their ability to control the release of glutamate and other neurotransmitters. They are also potential targets for novel pharmacotherapies for cocaine addiction. The present study investigated the impact of chronic cocaine self-administration (9.0 mg/kg/session for 100 sessions, 900 mg/kg total intake) on the densities of group II mGluRs, as assessed with in vitro receptor autoradiography, in the striatum of adult male rhesus monkeys. Binding of [³H]LY341495 to group II mGluRs in control animals was heterogeneous, with a medial to lateral gradient in binding density. Significant elevations in the density of group II mGluRs following chronic cocaine self-administration were measured in the dorsal, central and ventral portions of the caudate nucleus (P < 0.05), compared to controls. No differences in receptor density were observed between the groups in either the putamen or nucleus accumbens. These data demonstrate that group II mGluRs in the dorsal striatum are more sensitive to the effects of chronic cocaine exposure than those in the ventral striatum. Cocaine-induced dysregulation of the glutamate system, and its consequent impact on plasticity and synaptic remodeling, will likely be an important consideration in the development of novel pharmacotherapies for cocaine addiction.     

Quality of Web-based information on cocaine addiction

OBJECTIVE: To evaluate the quality of web-based information on cocaine use and addiction and to investigate potential content quality indicators. METHODS: Three keywords: cocaine, cocaine addiction and cocaine dependence were entered into two popular World Wide Web search engines. Websites were assessed with a standardized proforma designed to rate sites on the basis of accountability, presentation, interactivity, readability and content quality. "Health on the Net" (HON) quality label, and DISCERN scale scores aiding people without content expertise to assess quality of written health publication were used to verify their efficiency as quality indicators. RESULTS: Of the 120 websites identified, 61 were included. Most were commercial sites. The results of the study indicate low scores on each of the measures including content quality. A global score (the sum of accountability, interactivity, content quality and aesthetic criteria) appeared as a good content quality indicator. CONCLUSIONS: While cocaine education websites for patients are widespread, their global quality is poor. There is a need for better evidence-based information about cocaine use and addiction on the web. PRACTICE IMPLICATIONS: The poor and variable quality of web-based information and its possible impact on physician-patient relationship argue for a serious provider for patient talk about the health information found on Internet. Internet sites could improve their content using the global score as a quality indicator.     

Cocaine and apoptosis in myocardial cells

Toxic effects of cocaine on the heart muscle have been known for many years. Cardiovascular complications related to cocaine abuse include myocardial ischemia and infarction, inflammation, and disease of the heart muscle, rhythm disturbances, and sudden cardiac death. Cocaine toxicity-related cardiac morbidity and mortality are often due to several interacting mechanisms. Cocaine also has a potent pharmacological effect, indirectly stimulating the sympathetic nervous system, and it has a direct toxic effect on the heart. Although apoptosis (also called programmed cell death) has been shown to play an important role in the pathogenesis of several diseases in the heart, including heart failure and ischemic myocardial infarction, the role of apoptosis in the toxic effect of cocaine on the heart has not been explored. Recent studies indicated that cocaine causes apoptotic cell death in both adult and fetal heart muscles. Increased oxidative stress and reactive oxygen species, and the subsequent activation of a "stress responsive" enzyme (p38-mitogen-activated protein kinase) in the heart may play an important role in cocaine-induced apoptosis in the heart muscle. These findings suggest a new way to understand the cardiotoxic effects of cocaine, and may have potential clinical implications in the better management of cocaine-induced heart diseases. Anat Rec (New Anat): 257:208-216, 1999.     

Inhibiting activator protein-1 activity alters cocaine-induced gene expression and potentiates sensitization

We have expressed A-FOS, an inhibitor of activator protein-1 (AP-1) DNA binding, in adult mouse striatal neurons. We observed normal behavior including locomotion and exploratory activities. Following a single injection of cocaine, locomotion increased similarly in both the A-FOS expressing and littermate controls. However, following repeated injections of cocaine, the A-FOS expressing mice showed increased locomotion relative to littermate controls, an increase that persisted following a week of withdrawal and subsequent cocaine administration. These results indicate that AP-1 suppresses this behavioral response to cocaine. We analyzed mRNA from the striatum before and 4 and 24 h after a single cocaine injection in both A-FOS and control striata using Affymetrix microarrays (430 2.0 Array) to identify genes mis-regulated by A-FOS that may mediate the increased locomotor sensitization to cocaine. A-FOS expression did not change gene expression in the basal state or 4 h following cocaine treatment relative to controls. However, 24 h after an acute cocaine treatment, 84 genes were identified that were differentially expressed between the A-FOS and control mice. Fifty-six genes are down-regulated while 28 genes are up-regulated including previously identified candidates for addiction including brain-derived neurotrophic factor and period homolog 1. Using a random sample of identified genes, quantitative PCR was used to verify the microarray studies. The chromosomal location of these 84 genes was compared with human genome scans of addiction to identify potential genes in humans that are involved in addiction.     

Potential benefit of lamotrigine in managing ketamine use disorder

Ketamine is an anesthetic derivative of phencyclidine (PCP; ‘Angel dust’) with dissociative, analgesic and psychedelic properties. Ketamine has become a popular recreational drug of abuse in many parts of the world in recent years. The preclinical studies demonstrate the reinforcing effects of ketamine and long-term ketamine abuse induces a delayed and persistent upregulation of dopamine system. In humans, there have been concerns about its liability to development of addiction. The dilemma of mental professionals in managing the treatment-seeking ketamine abusers comes from a lack of effective pharmacotherapy. Limiting evidence showed that lamotrigine, which inhibits glutamate release, is effective to reduce cocaine craving. We propose that lamotrigine might be beneficial for managing ketamine use disorder clinically. We also reported one case of ketamine use disorder who experienced a great reduction in craving and ketamine use after taking lamotrigine. Although the mechanisms underlying neuroadaptation and reward related to ketamine are not entirely clear, future clinical trials are needed to advance our understanding of the benefit yielded by lamotrigine to treat ketamine use disorder.     

Interaction of carboxypeptidase A with monoclonal antibodies

Several mouse monoclonal antibodies to carboxypeptidase A (CPA) were prepared and purified, and their interaction with the enzyme was investigated. CPA is a well-characterized zinc-containing exopeptidase exhibiting peptidase as well as esterase activity. The antibodies obtained could be classified as follows: antibodies inhibiting mainly the peptidase activity of the enzyme, antibodies inhibiting mainly its esterase activity, antibodies affecting both activities, and antibodies which bind to the enzyme but have no marked effect on its catalytic properties. Binding constants of approximately 10(6) M-1 were obtained for most of the antibody-enzyme complexes tested. Additional information on the effect of the monoclonal antibodies on the active site of CPA was obtained by determining the change in the circular dichroism spectra of arsanilazotyrosine-248 carboxypeptidase A occurring as a result of the interaction of the enzyme with the antibodies studied. These findings suggest that CPA possesses at least three different specific antigenic sites, and that the active site of the enzyme for its peptidase activity differs from that for its esterase activity, though both sites seem to overlap to a considerable extent.     

A combination of buprenorphine and naltrexone blocks compulsive cocaine intake in rodents without producing dependence

Buprenorphine, a synthetic opioid that acts at both μ and κ opioid receptors, can decrease cocaine use in individuals with opioid addiction. However, the potent agonist action of buprenorphine at μ opioid receptors raises its potential for creating opioid dependence in non-opioid-dependent cocaine abusers. Here, we tested the hypothesis that a combination of buprenorphine and naltrexone (a potent μ opioid antagonist with weaker δ and κ antagonist properties) could block compulsive cocaine self-administration without producing opioid dependence. The effects of buprenorphine and various doses of naltrexone on cocaine self-administration were assessed in rats that self-administered cocaine under conditions of either short access (noncompulsive cocaine seeking) or extended access (compulsive cocaine seeking). Buprenorphine alone reproducibly decreased cocaine self-administration. Although this buprenorphine-alone effect was blocked in a dose-dependent manner by naltrexone in both the short-access and the extended-access groups, the combination of the lowest dose of naltrexone with buprenorphine blocked cocaine self-administration in the extended-access group but not in the short-access group. Rats given this low dose of naltrexone with buprenorphine did not exhibit the physical opioid withdrawal syndrome seen in rats treated with buprenorphine alone, and naltrexone at this dose did not block κ agonist-induced analgesia. The results suggest that the combination of buprenorphine and naltrexone at an appropriate dosage decreases compulsive cocaine self-administration with minimal liability to produce opioid dependence and may be useful as a treatment for cocaine addiction.     

Cocaine and the heart

There is increasing evidence that cocaine can have serious adverse effects on the heart. Angina, myocardial infarction, coronary artery spasm, arrhythmia, and sudden death have been reported in association with its use. There have been only two reports of actual myocardial pathology. In an attempt to clarify the pathophysiology of cocaine-associated cardiotoxicity and to search for pathologic changes that might be useful forensically, we reviewed random microscopic sections of hearts from 30 cases of cocaine-associated death seen by the San Francisco Medical Examiner. The age of the patients at death ranged from 25 to 74 years (mean 33.9 years). Pathologic findings included the presence of mild atherosclerotic coronary artery disease without evidence of thrombosis in three cases, associated with mild interstitial fibrosis in one case as well as mild focal myocardial fibrosis without coronary disease in four other cases. The most notable abnormality was the presence of myocardial contraction bands in 28 (93 per cent) cases. In comparison to 20 control cases of death secondary to sedative-hypnotic overdose, the hearts from the cases of cocaine-associated contained significantly more myocardial contraction bands (P less than .001; two-sided). The diffuseness of the contraction bands correlated directly with the level of cocaine found in the urine and blood at autopsy during routine screening. The presence and number of contraction bands in these cases was independent of other drugs found in the urine and blood, the number of sections of myocardium examined, and a history of attempted resuscitation. Contraction bands may act to supply the anatomic substrate for the arrhythmias associated with cocaine use. They may also provide a morphologic marker that can be sought in suspected cases of lethal cocaine overdose. Their presence may also suggest a cause of death in cases of sudden and unexpected death in which autopsy reveals no other pathology, and a drug screen is positive for cocaine.     

Properties of ligninase from Phanerochaete chrysosporium and their possible applications

The wood-degrading fungus Phanerochaete chrysosporium Burds produces a family of enzymes which degrade lignin and lignin-like substrates. These ligninases exhibit a high degree of homology in being hemeprotein peroxidases, in Mr, in cross reactivity to polyclonal antibodies, in being glycosylated, and in catalytic properties. The predominant ligninase is able to generate cation radicals in its aromatic substrates. These radicals can undergo a variety of reactions thus explaining the nonspecific nature of the enzyme. A similar mechanism is suggested for the other isoenzymes. There are numerous potential applications for ligninases. These include: biopulping, waste treatment of byproduct lignins, detoxification of environmental pollutants, and modification of lignins to produce small molecular weight organics.