Effects of acute and chronic aripiprazole treatment on choice between cocaine self-administration and food under a concurrent schedule of reinforcement in rats

Rationale  Dopamine D2-like partial agonists such as aripiprazole have received some attention as potential pharmacotherapies for the treatment of psychostimulant addiction. However, the preclinical evaluations so far have focused on acute effects of aripiprazole. Objectives  We tested the hypothesis that aripiprazole, both as acute and as chronic treatment, would preferentially decrease cocaine self-administration while sparing behavior maintained by a natural reinforcer, resulting in a shift in the allocation of behavior from cocaine-taking towards the alternative reinforcer. Materials and methods  Rats were trained to self-administer intravenous cocaine in a concurrent choice procedure, with a palatable food as the competing reinforcer, under a fixed ratio (FR) 1 FR 5 chain schedule. Aripiprazole was then administered as continuous infusion by osmotic minipumps for 5 days, during which performance in the choice procedure was assessed daily. Results  An intermediate dose of aripiprazole decreased cocaine self-administration and shifted the cocaine choice curve to the right as an acute treatment. However, as a chronic treatment, aripiprazole failed to decrease cocaine self-administration or cocaine choice, despite a dose-dependent decrease in overall response rates and food-maintained behavior. Conclusions  Our results confirm and extend earlier findings and indicate that acute administration of aripiprazole can decrease cocaine self-administration. However, based on the present data, chronic treatment with aripiprazole does not show much promise as a potential pharmacotherapy for cocaine addiction. Both acute and chronic treatment data are in agreement with published clinical findings, suggesting that the concurrent choice procedure in rats has predictive validity of efficacy in humans.     

An exploration of the social stigma of tuberculosis in five "municipios" of Nicaragua to reflect on local interventions

OBJECTIVE: The social stigma of tuberculosis is much less studied than those of other diseases such as AIDS or mental problems. However, it has important implications on the affected person's well being and on the epidemic's control. Our study aims at exploring this social stigma in five local health systems of Nicaragua, prior to implementing interventions to reduce it. METHODS: Through in-depth interviews and focus groups involving stakeholders in the care of people affected by tuberculosis (PATBs), we analysed interactions between PATBs and family members, first line government health services' personnel, and community members. RESULTS: According to our results, the interaction between stakeholders and PATBs can be described as the intersection between two sets of contradictory feelings and attitudes: (a) feelings of affection and supportive attitudes toward PATBs opposed to the fear of being infected or that PATBs will infect others and, (b) confidence in PATBs considered to be unlucky opposed to mistrust of PATBs considered to be negligent. PATBs react against this mainly by hiding their condition which leads them to a, loss of confidence and depression. This intricate group of feelings and attitudes is influenced by two sets of determinants related to domination and power between stakeholders and issues of knowledge and information. CONCLUSION: Analysing tuberculosis-related social stigma as a social process enabled us to better understand some key social structural factors of health care system's organisation and identify locally acceptable interventions to reduce such stigma. The fact of analysing, in a more thorough study, some interventions in the currently changing social structural context of health care systems in Nicaragua will give us a better insight into the relevance of our analysis and the interventions' effectiveness in reducing the social stigma of tuberculosis.     

Can the aqueous decoction of mango flowers be used as an antiulcer agent?

This study was designed to determine the effect of Mangifera indica flowers decoction, on the acute and subacute models of induced ulcer in mice and rats. A single oral administration of the aqueous decoction (AD) from M. indica up to a dose of 5 g/kg, p.o. did not produce any signs or symptom of toxicity in the treated animals. The oral pre-treatment with AD (250, 500 and 1000 mg/kg) in rats with gastric lesions induced by ethanol, decreased the gastric lesions from 89.0+/-6.71 (control group) to 9.25+/-2.75, 4.50+/-3.30 and 0, respectively. Pretreatment with AD (250, 500 and 1000 mg/kg) to mice with HCl/ethanol- or stress-induced gastric lesions resulted in a dose-dependent significant decrease of lesion index. In the piroxicam-induced gastric lesions, the gastroprotective effect of AD was reducing with the increase of the AD dose. In the pylorus-ligature, AD (p.o.) significantly decreased the acid output indicating the antisecretory property involved in the gastroprotective effect of M. indica. Treatment with AD during 14 consecutive days significantly accelerated the healing process in subacute gastric ulcer induced by acetic acid in rats. Pretreatment with N-nitro-l-arginine methyl ester (l-NAME), an inhibitor of NO-synthase, did not abolish the gastroprotective effects (99% with saline versus 80% with l-NAME) of AD against ethanol-induced gastric lesions. Pretreatment with N-ethylmaleimide (NEM), a blocker of endogenous sulphydryl group, significantly abolished the protective effects of AD against ethanol-induced gastric ulcers (95% with saline versus 47% with NEM). Phytochemical screening showed the presence of steroids, triterpenes, phenolic compounds and flavonoids. Estimation of the global polyphenol content in the AD was performed by Folin-Ciocalteu method and showed approximately 53% of total phenolic on this extract. These findings indicate the potential gastroprotective and ulcer-healing properties of aqueous decoction of M. indica flowers and further support its popular use in gastrointestinal disorders in Caribbean.     

One health disparities and COVID-19

 The global impact of the COVID-19 pandemic has disproportionately affected some communities and populations more than others. We propose that an interdisciplinary framework of ‘One Health Disparities’ advances understanding of the social and systemic issues that drive COVID-19 in vulnerable populations. One Health Disparities integrates the social environment with One Health perspectives on the interconnectedness of human, animal, and environmental health. To apply this framework, we consider One Health Disparities that emerge in three key components of disease transmission: exposure, susceptibility, and disease expression. Exposure disparities arise through variation in contact with COVID-19’s causative agent, SARS-CoV-2. Disparities in susceptibility and disease expression also exist; these are driven by biological and social factors, such as diabetes and obesity, and through variation in access to healthcare. We close by considering how One Health Disparities informs understanding of spillback into new animal reservoirs, and what this might mean for further human health disparities.Lay summaryOne Health focuses on interconnections between human, animal, and environmental health. We propose that social environments are also important to One Health and help illuminate disparities in the coronavirus pandemic, including its origins, transmission and susceptibility among humans, and spillback to other species. We call this framework One Health Disparities.     

Nicotine improves probabilistic reward learning in wildtype but not alpha7 nAChR null mutants,yet alpha7 nAChR agonists do not improve probabilistic learning

Cognitive impairments, e.g., reward learning, are present in various psychiatric disorders and warrant treatment. Improving reward-related learning could synergistically enhance psychosocial treatments and cognition generally. A critical first step is to understand the mechanisms underlying reward learning. The dopamine system has been implicated in such learning, but less known is how indirect activation of this system may affect reward learning. We determined the role of alpha7 nicotinic acetylcholine receptors (nAChR) on a probabilistic reversal learning task (PRLT) in mice that includes reward and punishment. Male alpha7 knockout (KO), heterozygous (HT), and wildtype (WT) littermate mice (n?=?84) were treated with vehicle, 0.03, or 0.3?mg/kg nicotine. Two cohorts of C57BL/6NJ male mice were treated with various alpha7 nAChR ligands, including the full agonists PNU282877 and AR-R-17779, the positive allosteric modulator CCMI, the partial agonist SSR180711, and the antagonist methyllycaconitine. All mice were then tested in the PRLT. Nicotine (0.3?mg/kg) significantly improved initial reward learning in alpha7 WT and HT mice but did not improve learning in KO mice, suggesting an involvement of the alpha7 nAChR in the pro-learning effects of nicotine. Neither alpha7 nAChR treatments (PNU282987, AR-R-17779, CCMI, SSR180711, nor methyllycaconitine) affected mouse PRLT performance however. Nicotine improved reward learning via a mechanism that may include alpha7 nAChRs. This improvement unlikely relied solely on alpha7 nAChRs however, since no alpha7 nAChR ligand improved reward learning in normal mice. Future assessments of the effects of other nAChR subtypes on reward learning are needed.     

The Relationship Between Diabetes Attitudes and Treatment Among Free Clinic Patients and Volunteers

Free clinics provide free primary care to the under or uninsured and have been playing an important role in serving the socio-economically disadvantaged. Free clinic patients represent a group of people who experience significant barriers to receiving diabetes prevention and intervention. This study examined diabetes attitudes among free clinic patients and volunteers. English or Spanish speaking patients and volunteers (N = 384), aged 18 years or older completed a self-administered survey. Diabetic patients and volunteers shared similar levels of diabetes attitudes compared to non-diabetic patients. Among patients, ethnicity, education level, diabetes education, and family history affected diabetes attitudes. Among volunteers, diabetes education was an important factor associated with positive diabetes attitudes. Whether the volunteer is a healthcare professional or student was related only to one aspect of diabetes attitudes, seriousness of type 2 diabetes. The results, indicating free clinic diabetic patients and volunteers shared similar levels of diabetes attitudes, were positive for maintaining and developing diabetes education programs at a free clinic. Unfortunately, the average length of volunteering at this free clinic was short and student volunteers likely leave the clinic upon graduation. Future research should examine issues of volunteer retention in free clinics. Diabetes education for patients may need to be diversified according to ethnicity, family history of diabetes, and educational level. Finally, non-healthcare professional volunteers could potentially be involved in diabetes education at a free clinic.     

Synthetic N-pyridinyl(methyl)-indol-3-ylpropanamides as new potential immunosuppressive agents

Several N-pyridinyl(methyl)-indol-3-ylpropanamides were synthesized and pharmacological evaluations of their immunosuppressive potential were performed. Among thirteen compounds tested in vitro on murine T proliferation, three showed interesting inhibiting activity. For the most active compound (propanamide 18), immunosuppressive activity was documented both in vitro on human T lymphocytes proliferation and in vivo on mice delayed-type hypersensitivity. These experimental data demonstrated that these compounds hold potential as immunosuppressive agents.     

Identification by genomic immunization of a pool of DNA vaccine candidates that confer protective immunity in mice against Neisseria meningitidis serogroup B

We have shown previously that expression library immunization is viable alternative approach to induce protective immunity against Neisseria meningitidis serogroup B. In this study we report that few rounds of library screening allow identification of protective pools of defined antigens. A previously reported protective meningococcal library (L8, with 600 clones) was screened and two sub-libraries of 95 clones each were selected based on the induction of bactericidal and protective antibodies in BALB/c mice. After sequence analysis of each clone within these sub-libraries, we identified a pool of 20 individual antigens that induced protective immune responses in mice against N. meningitidis infection, and the observed protection was associated with the induction of bactericidal antibodies. Our studies demonstrate for the first time that ELI combined with sequence analysis is a powerful and efficient tool for identification of candidate antigens for use in a meningococcal vaccine.     

Patterns of transcription factor programs and immune pathway activation define four major subtypes of SCLC with distinct therapeutic vulnerabilities

1. Download : Download high-res image (242KB)
2. Download : Download full-size image