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1.
Educ Health (Abingdon) ; 36(1): 38-46, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38047346

RESUMEN

Background: Despite female genital mutilation/cutting (FGM/C) practices being an illegal form of gender-based violence in Canada, this practice impacts many Canadians. Lack of education and training among Canadian health-care providers has resulted in systematic barriers to care. Awareness and FGM/C-related education among Canadian health-care providers must be urgently assessed. Methods: Canadian medical students were recruited to complete an anonymous survey via E-mails distributed through their schools' student organization between January and March 2021. We evaluated student understanding of FGM/C, attitudes toward medicalization and legislation, and prior clinical experience using multiple choice, Likert scale, and open-response questions. Results: Respondents (n = 135) performed poorly on knowledge assessment questions (mean percent correct <50%). Only 10.4% of respondents indicated knowing how to involve appropriate authorities when necessary, and most never evaluate FGM/C in patient history (86.7%) or clinical examination (57.1%). Subgroup analysis revealed that prior education significantly improved knowledge scores and influenced students' behaviors and attitudes. About 92.2% of respondents supported the integration of FGM/C curricula in undergraduate medical education. Discussion: This study reveals that Canadian medical students have a poor understanding of FGM/C and are not prepared to identify affected patients or intervene when necessary. These results provide rationale for the implementation of FGM/C-learning modules in undergraduate medicine.


Asunto(s)
Circuncisión Femenina , Estudiantes de Medicina , Humanos , Femenino , Circuncisión Femenina/métodos , Conocimientos, Actitudes y Práctica en Salud , Canadá , Aprendizaje
2.
Biochem Cell Biol ; 101(4): 326-360, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37040564

RESUMEN

Graduate students are vital to the creation of research and innovation in Canada. The National Graduate Student Finance Survey was launched in 2021 by the Ottawa Science Policy Network to investigate the financial realities of Canadian graduate students. Closing in April 2022, the survey received 1305 responses from graduate students representing various geographical locations, years of study, fields of education, and demographic backgrounds. The results capture a snapshot into graduate student finances, including an in-depth analysis of stipends, scholarships, debt, tuition, and living expenses. In its entirety, we found that the majority of graduate students are facing serious financial concerns. This is largely due to stagnant funding for students both from federal and provincial granting agencies and from within their institutions. This reality is even worse for international students, members of historically underrepresented communities, and those with dependents, all of whom experience additional challenges that impact their financial security. Based on our findings, we propose several recommendations to the Tri-Council agencies (Natural Sciences and Engineering Research Council, Social Science and Humanities Research Council, and Canadian Institute for Health Research) and academic institutions to strengthen graduate student finances and help sustain the future of research in Canada.


Asunto(s)
Estrés Financiero , Estudiantes , Humanos , Canadá
3.
Sci Rep ; 13(1): 3347, 2023 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-36849805

RESUMEN

We conducted a systematic review and meta-analysis of randomized control trials to formally assess the safety and efficacy of autologous whole cell vaccines as immunotherapies for solid tumors. Our primary safety outcome was number, and grade of adverse events. Our primary efficacy outcome was clinical responses. Secondary outcomes included survival metrics and correlative immune assays. We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published between 1946 and August 2020 using any autologous whole cell product in the treatment of any solid tumor. The Cochrane Randomized Controlled Trial risk of bias tool was used to assess risk of bias. Eighteen manuscripts were identified with a total of 714 patients enrolled in control and 808 in vaccine arms. In 698 patients receiving at least one dose of vaccine, treatment was well tolerated with a total of 5 grade III or higher adverse events. Clinical response was reported in a minority (n = 2, 14%) of studies. Autologous cell vaccines were associated with improved overall (HR 1.28, 95% CI 1.01-1.63) and disease-free survival (HR 1.33, 95% CI 1.05-1.67) over thirteen and ten trials respectively. Where reported, immune assays correlated well with clinical outcomes. Our results suggest that autologous whole cell vaccination is safe and efficacious in increasing survival in patients undergoing treatment for solid tumors.Registration: PROSPERO CRD42019140187.


Asunto(s)
Vacunas contra el Cáncer , Neoplasias , Humanos , Vacunas contra el Cáncer/efectos adversos , Inmunoterapia , Neoplasias/terapia
4.
Commun Biol ; 5(1): 463, 2022 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-35577895

RESUMEN

Top-down effects, like predation, are drivers of insect outbreaks, but bottom-up effects, like host nutritional quality, also influence outbreaks and could in turn be altered by insect-caused defoliation. We evaluated the prediction that herbivory leads to a positive feedback on outbreak severity as nutrient concentration in plant tissues increases through improved soil nutrient availability from frass and litter deposition. Over seven years of a spruce budworm outbreak, we quantified litter nutrient fluxes, soil nitrogen availability, and host tree foliar nutrient status along a forest susceptibility gradient. As the outbreak progressed, both soil nutrient fluxes and availability increased which, in turn, improved foliage quality in surviving host trees. This is consistent with boosted insect fitness and increased population density and defoliation as outbreaks grow. Our results suggest that a positive bottom-up feedback to forest ecosystems from defoliation may result in conditions favorable to self-amplifying population dynamics in insect herbivores that can contribute to driving broad-scale outbreaks.


Asunto(s)
Hemípteros , Mariposas Nocturnas , Animales , Brotes de Enfermedades , Ecosistema , Insectos , Suelo , Árboles
5.
Circ Res ; 130(6): 831-847, 2022 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-35137605

RESUMEN

RATIONALE: Atherosclerosis is characterized by an accumulation of foam cells within the arterial wall, resulting from excess cholesterol uptake and buildup of cytosolic lipid droplets (LDs). Autophagy promotes LD clearance by freeing stored cholesterol for efflux, a process that has been shown to be atheroprotective. While the role of autophagy in LD catabolism has been studied in macrophage-derived foam cells, this has remained unexplored in vascular smooth muscle cell (VSMC)-derived foam cells that constitute a large fraction of foam cells within atherosclerotic lesions. OBJECTIVE: We performed a comparative analysis of autophagy flux in lipid-rich aortic intimal populations to determine whether VSMC-derived foam cells metabolize LDs similarly to their macrophage counterparts. METHODS AND RESULTS: Atherosclerosis was induced in GFP-LC3 (microtubule-associated proteins 1A/1B light chain 3) transgenic mice by PCSK9 (proprotein convertase subtilisin/kexin type 9)-adeno-associated viral injection and Western diet feeding. Using flow cytometry of aortic digests, we observed a significant increase in dysfunctional autophagy of VSMC-derived foam cells during atherogenesis relative to macrophage-derived foam cells. Using cell culture models of lipid-loaded VSMCs and macrophages, we show that autophagy-mediated cholesterol efflux from VSMC foam cells was poor relative to macrophage foam cells, and largely occurs when HDL (high-density lipoprotein) was used as a cholesterol acceptor, as opposed to apoA-1 (apolipoproteinA-1). This was associated with the predominant expression of ABCG1 in VSMC foam cells. Using metformin, an autophagy activator, cholesterol efflux to HDL was significantly increased in VSMC, but not in macrophage, foam cells. CONCLUSIONS: These data demonstrate that VSMC and macrophage foam cells perform cholesterol efflux by distinct mechanisms, and that autophagy flux is highly impaired in VSMC foam cells, but can be induced by pharmacological means. Further investigation is warranted into targeting autophagy specifically in VSMC foam cells, the predominant foam cell subtype of advanced atherosclerotic plaques, to promote reverse cholesterol transport and resolution of the atherosclerotic plaque.


Asunto(s)
Aterosclerosis , Placa Aterosclerótica , Animales , Aterosclerosis/metabolismo , Autofagia , Colesterol/metabolismo , Células Espumosas/metabolismo , Leucocitos/metabolismo , Ratones , Músculo Liso Vascular/metabolismo , Placa Aterosclerótica/patología , Proproteína Convertasa 9/metabolismo
6.
Hematol Oncol ; 39(4): 448-464, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33963789

RESUMEN

Autologous cell vaccines use a patient's tumor cells to stimulate a broad antitumor response in vivo. This approach shows promise for treating hematologic cancers in early phase clinical trials, but overall safety and efficacy remain poorly described. We conducted a systematic review assessing the use of autologous cell vaccination in treating hematologic cancers. Primary outcomes of interest were safety and clinical response, with secondary outcomes including survival, relapse rate, correlative immune assays and health-quality related metrics. We performed a search of MEDLINE, Embase and the Cochrane Register of Controlled Trials including any interventional trial employing an autologous, whole cell product in any hematologic malignancy. Risk of bias was assessed using a modified Institute of Health Economics tool. Across 20 single arm studies, only 341 of 592 enrolled participants received one or more vaccinations. Primary reasons for not receiving vaccination included rapid disease progression/death and manufacturing challenges. Overall, few high-grade adverse events were observed. One death was reported and attributed to a GM-CSF producing allogeneic cell line co-administered with the autologous vaccine. Of 58 evaluable patients, the complete response rate was 21.0% [95% CI, 10.4%-37.8%)] and overall response rate was 35.8% (95% CI, 24.4%-49.0%). Of 97 evaluable patients for survival, the 5-years overall survival rate was 64.9% (95% CI, 52.6%-77.2%) and disease-free survival was 59.7% (95% CI, 47.7%-71.7%). We conclude that, in hematologic malignancies, based on limited available data, autologous cell vaccines are safe and display a trend towards efficacy but that challenges exist in vaccine manufacture and administration.


Asunto(s)
Neoplasias Hematológicas/terapia , Vacunas/uso terapéutico , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vacunas/farmacología
7.
Front Immunol ; 11: 1512, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32655581

RESUMEN

Natural Killer (NK) cells are innate immune responders critical for viral clearance and immunomodulation. Despite their vital role in viral infection, the contribution of NK cells in fighting SARS-CoV-2 has not yet been directly investigated. Insights into pathophysiology and therapeutic opportunities can therefore be inferred from studies assessing NK cell phenotype and function during SARS, MERS, and COVID-19. These studies suggest a reduction in circulating NK cell numbers and/or an exhausted phenotype following infection and hint toward the dampening of NK cell responses by coronaviruses. Reduced circulating NK cell levels and exhaustion may be directly responsible for the progression and severity of COVID-19. Conversely, in light of data linking inflammation with coronavirus disease severity, it is necessary to examine NK cell potential in mediating immunopathology. A common feature of coronavirus infections is that significant morbidity and mortality is associated with lung injury and acute respiratory distress syndrome resulting from an exaggerated immune response, of which NK cells are an important component. In this review, we summarize the current understanding of how NK cells respond in both early and late coronavirus infections, and the implication for ongoing COVID-19 clinical trials. Using this immunological lens, we outline recommendations for therapeutic strategies against COVID-19 in clearing the virus while preventing the harm of immunopathological responses.


Asunto(s)
Traslado Adoptivo/métodos , Betacoronavirus/inmunología , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/inmunología , Células Asesinas Naturales/inmunología , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/inmunología , Corticoesteroides/uso terapéutico , Animales , Antiinflamatorios no Esteroideos/uso terapéutico , Ácido Ascórbico/uso terapéutico , Betacoronavirus/efectos de los fármacos , COVID-19 , Infecciones por Coronavirus/mortalidad , Infecciones por Coronavirus/virología , Citocinas/antagonistas & inhibidores , Citocinas/metabolismo , Susceptibilidad a Enfermedades/inmunología , Humanos , Inmunidad Innata/efectos de los fármacos , Inmunidad Innata/inmunología , Memoria Inmunológica , Interferón Tipo I/metabolismo , Interferón Tipo I/uso terapéutico , Células Asesinas Naturales/efectos de los fármacos , Ratones , Pandemias , Neumonía Viral/mortalidad , Neumonía Viral/virología , SARS-CoV-2
8.
Ecol Appl ; 28(5): 1245-1259, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29645330

RESUMEN

Canada's forests are shaped by disturbances such as fire, insect outbreaks, and droughts that often overlap in time and space. The resulting cumulative disturbance risks and potential impacts on forests are generally not well accounted for by models used to predict future impacts of disturbances on forest. This study aims at projecting future cumulative effects of four main natural disturbances, fire, mountain pine beetle, spruce budworm and drought, on timber volumes across Canada's forests using an approach that accounts for potential overlap among disturbances. Available predictive models for the four natural disturbances were used to project timber volumes at risk under aggressive climate forcing up to 2100. Projections applied to the current vegetation suggest increases of volumes at risk related to fire, mountain pine beetle, and drought over time in many regions of Canada, but a decrease of the volume at risk related to spruce budworm. When disturbance effects are accumulated, important changes in volumes at risk are projected to occur as early as 2011-2041, particularly in central and eastern Canada. In our last simulation period covering 2071-2100, nearly all timber volumes in most of Canada's forest regions could be at risk of being affected by at least one of the four natural disturbances considered in our analysis, a six-fold increase relative to the baseline period (1981-2010). Tree species particularly vulnerable to specific disturbances (e.g., trembling aspen to drought) could suffer disproportionate increases in their volume at risk with potential impacts on forest composition. By 2100, estimated wood volumes not considered to be at risk could be lower than current annual timber harvests in central and eastern Canada. Current level of harvesting could thus be difficult to maintain without the implementation of adaptation measures to cope with these disturbances.


Asunto(s)
Sequías , Incendios , Agricultura Forestal , Herbivoria , Árboles/fisiología , Animales , Canadá , Modelos Biológicos , Mariposas Nocturnas/fisiología , Gorgojos/fisiología
9.
Mol Neurobiol ; 54(9): 7534-7548, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-27826748

RESUMEN

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a 38-amino acid neuropeptide which has been shown to exert various neuroprotective actions in vitro and in vivo; however, the ability of endogenous PACAP to prevent cell death in vivo remains to be elucidated. To explore the capacity of endogenous PACAP to prevent ethanol toxicity, adolescent and adult PACAP knockout (KO) mice were injected with ethanol in a binge drinking-like manner. Biochemical analyses revealed that ethanol administration induced an increase in the production of reactive oxygen species and the activity of caspase-3 in PACAP KO mice in an age-independent manner. In order to characterize the mechanisms underlying the sensitivity of PACAP KO mice, a whole-genome microarray analysis was performed to compare gene regulations induced by ethanol in adolescent and adult wild-type and PACAP KO mice. Gene expression substantially differed between adolescent and adult wild-type mice, suggesting distinct effects of ethanol according to the state of brain maturation. Interestingly, in adolescent and adult PACAP KO mice, the set of genes regulated were also markedly different but seemed to inhibit some similar regulatory network processes associated in particular with DNA repair and cell cycle. These data imply that ethanol induces serious DNA damages and cell cycle alteration in PACAP KO mice. This hypothesis, based on the transcriptomic data, could be confirmed by functional studies which showed that cell proliferation decreased in adolescent and adult PACAP KO mice treated with ethanol but recovered after a 30-day withdrawal period. These data, obtained with PACAP KO animals, demonstrate that endogenous PACAP protects the brain of adolescent and adult mice from alcohol toxicity and modulates distinct sets of genes according to the maturation status of the brain.


Asunto(s)
Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Etanol/toxicidad , Redes Reguladoras de Genes/efectos de los fármacos , Redes Reguladoras de Genes/fisiología , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/deficiencia , Factores de Edad , Animales , Animales Recién Nacidos , Regulación de la Expresión Génica , Ratones , Ratones Noqueados , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/genética
10.
Psychopharmacology (Berl) ; 232(15): 2711-21, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25761842

RESUMEN

RATIONALE: Drug addiction is defined as a recurring cycle of intoxication, abstinence and relapse. The behavioural trait of novelty seeking is frequently observed in alcohol abusers. Moreover, converging evidence indicates that anxious individuals are also predisposed to alcohol abuse. OBJECTIVES: We have analyzed the respective implication of those two behavioural factors on vulnerability to ethanol intake on rats in situations designed to reflect drug intoxication and relapse phases in humans. METHODS: In a general population of Wistar rats, animals were tested in both the light/dark box and the novelty preference tests. Ethanol consumption was measured in a two-bottle free-choice procedure across three successive procedures. Animals were first exposed to increasing concentrations of ethanol (2, 4, 6, 8, 10, 12 % for 8 days at each concentration). Then, the concentration of the solution was diminished from 12 to 6 %. Finally, all rats were re-exposed to 6 % ethanol after 12 days of ethanol deprivation. RESULTS: Novelty preference predicted the amount of ethanol consumed across all phases. In contrast, anxiety was associated with a quicker recovery of ethanol consumption after the concentration drop and a greater increase in ethanol consumption after deprivation. CONCLUSIONS: Novelty seeking and anxiety are both but differentially implicated in predisposition to ethanol abuse. Whereas novelty seeking is related to the amount of ethanol consumed, anxiety is associated to higher ethanol consumption when ethanol concentration is decreased or after ethanol deprivation.


Asunto(s)
Consumo de Bebidas Alcohólicas/psicología , Ansiedad/psicología , Conducta de Elección/efectos de los fármacos , Etanol/administración & dosificación , Conducta Exploratoria/efectos de los fármacos , Animales , Conducta Animal/efectos de los fármacos , Individualidad , Masculino , Ratas , Ratas Wistar
11.
J Neurochem ; 132(6): 629-41, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25556946

RESUMEN

A major cause of alcohol toxicity is the production of reactive oxygen species generated during ethanol metabolism. The aim of this study was to compare the effect of binge drinking-like alcohol exposure on a panel of genes implicated in oxidative mechanisms in adolescent and adult mice. In adolescent animals, alcohol decreased the expression of genes involved in the repair and protection of oxidative DNA damage such as atr, gpx7, or nudt15 and increased the expression of proapoptotic genes such as casp3. In contrast, in the adult brain, genes activated by alcohol were mainly associated with protective mechanisms that prevent cells from oxidative damage. Whatever the age, iterative binge-like episodes provoked the same deleterious effects as those observed after a single binge episode. In adolescent mice, multiple binge ethanol exposure substantially reduced neurogenesis in the dentate gyrus and impaired short-term memory in the novel object and passive avoidance tests. Taken together, our results indicate that alcohol causes deleterious effects in the adolescent brain which are distinct from those observed in adults. These data contribute to explain the greater sensitivity of the adolescent brain to alcohol toxicity. The effects of alcohol exposure were investigated on genes involved in oxidative mechanisms. In adolescent animals, alcohol decreased the expression of genes involved in DNA repair, a potential cause of the observed decrease of neurogenesis. In contrast, in the adult brain, alcohol increased the expression of genes associated with antioxidant mechanisms. Apoptosis was increase in all groups and converged with other biochemical alterations to enhance short-term memory impairment in the adolescent brain. These data contribute to explain the greater sensitivity of the adolescent brain to alcohol toxicity.


Asunto(s)
Consumo Excesivo de Bebidas Alcohólicas/sangre , Consumo Excesivo de Bebidas Alcohólicas/genética , Daño del ADN/fisiología , Etanol/toxicidad , Estrés Oxidativo/fisiología , Factores de Edad , Animales , Consumo Excesivo de Bebidas Alcohólicas/psicología , Daño del ADN/efectos de los fármacos , Etanol/administración & dosificación , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos
12.
Nat Neurosci ; 17(7): 923-33, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24859200

RESUMEN

Neuronal migration disorders such as lissencephaly and subcortical band heterotopia are associated with epilepsy and intellectual disability. DCX, PAFAH1B1 and TUBA1A are mutated in these disorders; however, corresponding mouse mutants do not show heterotopic neurons in the neocortex. In contrast, spontaneously arisen HeCo mice display this phenotype, and our study revealed that misplaced apical progenitors contribute to heterotopia formation. While HeCo neurons migrated at the same speed as wild type, abnormally distributed dividing progenitors were found throughout the cortical wall from embryonic day 13. We identified Eml1, encoding a microtubule-associated protein, as the gene mutated in HeCo mice. Full-length transcripts were lacking as a result of a retrotransposon insertion in an intron. Eml1 knockdown mimicked the HeCo progenitor phenotype and reexpression rescued it. We further found EML1 to be mutated in ribbon-like heterotopia in humans. Our data link abnormal spindle orientations, ectopic progenitors and severe heterotopia in mouse and human.


Asunto(s)
Coristoma/genética , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/fisiología , Mutación/fisiología , Células-Madre Neurales/fisiología , Secuencia de Aminoácidos , Animales , Bromodesoxiuridina , Ciclo Celular/fisiología , Movimiento Celular/fisiología , Corteza Cerebral/citología , Corteza Cerebral/embriología , Lisencefalias Clásicas y Heterotopias Subcorticales en Banda , Proteína Doblecortina , Electroporación , Humanos , Inmunohistoquímica , Malformaciones Arteriovenosas Intracraneales/patología , Intrones/genética , Ratones , Microscopía Confocal , Microtúbulos/fisiología , Mitosis/fisiología , Datos de Secuencia Molecular , Retroelementos/fisiología , Huso Acromático/fisiología
13.
Behav Brain Res ; 197(2): 311-6, 2009 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-18793676

RESUMEN

Some clinical studies have shown that anxiety disorders are often associated with drug dependence, although it remains unclear whether these disorders are primary or secondary to drug abuse. We have investigated whether anxiety may be a factor that predisposes to cocaine use. From an outbred Wistar strain, we have selected male rats regarded as anxious or non-anxious on the basis of their scores on two behavioural tests of unconditioned anxiety, the elevated plus-maze and the light/dark box test. They were also screened for their locomotor activity in an inescapable novel environment and for their preference for novelty presented in a free-choice. Rewarding effects of cocaine (2.5-20 mg/kg; i.p.) were then determined in the conditioned place preference paradigm (CPP). Anxious and non-anxious rats showed no difference in their responsiveness to inescapable novelty or their preference for novelty in a free-choice procedure. Only anxious rats developed a CPP induced by increasing doses of cocaine, the magnitude of CPP induced by the 10 mg/kg dose of cocaine being significantly higher than that observed in anxious rats conditioned with saline. These results suggest that anxiety affects the sensitivity to aversive/anxiogenic effects of cocaine. Thus, anxious rats which were highly responsive to positive effects of cocaine may be more prone to develop cocaine addiction than non-anxious rats.


Asunto(s)
Ansiedad/fisiopatología , Cocaína/farmacología , Condicionamiento Psicológico/efectos de los fármacos , Conducta Exploratoria/efectos de los fármacos , Análisis de Varianza , Animales , Aprendizaje por Asociación/efectos de los fármacos , Aprendizaje por Asociación/fisiología , Reacción de Prevención/efectos de los fármacos , Reacción de Prevención/fisiología , Cocaína/administración & dosificación , Condicionamiento Psicológico/fisiología , Conducta Exploratoria/fisiología , Inyecciones Intraperitoneales , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Ratones , Ratas , Ratas Wistar , Recompensa , Estimulación Química
14.
Eur J Pharmacol ; 586(1-3): 197-204, 2008 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-18400220

RESUMEN

The consequences of the consumption of cannabinoids with other drugs of abuse are of particular medical relevance. Several studies investigated the ability of cannabinoids to induce a locomotor cross-sensitization to other addictive drugs, but results remain inconsistent. Therefore, we investigated in mice the consequences of a repeated treatment with the cannabinoid agonist HU 210 on motor effects of morphine or alcohol. In mice receiving a daily injection of HU 210 (12.5 to 200 microg/kg) during 7 days, no hetero-sensitization to the stimulation induced by either morphine (7.5 mg/kg) or alcohol (1 or 1.5 g/kg) emerged, from 1 day up to 35 days after the end of the sub-chronic treatment with HU 210. Even a chronic treatment with a high dose of HU 210 (14 days, 200 microg/kg) induced no subsequent enhancement of the stimulant effects of morphine or alcohol. In fact, the motor stimulant effect of morphine or alcohol in chronically HU 210 pre-treated mice was even abolished until the 3rd day of abstinence. This reduction was presumably due to residual HU 210 since this effect was prevented by the cannabinoid antagonist rimonabant. Afterwards, chronically cannabinoid pre-treated mice remained less active than vehicle pre-treated mice from the 7th day up to the 35th day after the end of the 14-day treatment with HU 210. In conclusion, we failed to detect any hetero-sensitization whatever the pre-treatment regimen. However, only after the 14-day regimen, HU 210 pre-treated mice displayed a long-lasting decrease in activity, suggesting that some neuronal adaptive changes may have occurred.


Asunto(s)
Analgésicos Opioides/farmacología , Agonistas de Receptores de Cannabinoides , Depresores del Sistema Nervioso Central/farmacología , Dronabinol/análogos & derivados , Etanol/farmacología , Morfina/farmacología , Actividad Motora/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Dronabinol/farmacología , Masculino , Ratones , Piperidinas/farmacología , Pirazoles/farmacología , Rimonabant
15.
Behav Brain Res ; 178(2): 274-82, 2007 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-17254644

RESUMEN

Previous studies evidenced in rats the suppression by cannabinoids of motor stimulant effects of various drugs of abuse. Here we investigated, in mice, the effects of an acute or a chronic administration with the cannabinoid agonist HU 210 on the motor stimulant effects of either morphine or alcohol. HU 210 (12.5-200 microg/kg), when acutely administered, antagonized the stimulant effects of morphine (7.5 mg/kg) or alcohol (1 or 1.5 g/kg). A tolerance to this antagonistic interaction with morphine and alcohol occurred after a 7-day or a 14-day HU 210 treatment, leading to the reappearance of morphine- and alcohol-induced stimulation. The CB1 receptor antagonist rimonabant (10 mg/kg) enhanced the stimulant effect induced by low doses of morphine (5 or 7.5 mg/kg). Rimonabant (3 or 10 mg/kg) altered the locomotor effect of alcohol in a biphasic manner. It enhanced the stimulant effect of low doses of alcohol (1 or 1.5 g/kg) while decreasing the locomotor activity of mice treated with a high dose (3 g/kg) of alcohol. Furthermore, rimonabant (3 and 10 mg/kg) enhanced the duration of alcohol-induced loss of righting reflex (4 g/kg), suggesting a dual implication of cannabinoidergic pathways in acute effects of alcohol.


Asunto(s)
Estimulantes del Sistema Nervioso Central/antagonistas & inhibidores , Etanol/farmacología , Morfina/farmacología , Actividad Motora/efectos de los fármacos , Receptores de Cannabinoides/metabolismo , Análisis de Varianza , Animales , Antagonistas de Receptores de Cannabinoides , Estimulantes del Sistema Nervioso Central/farmacología , Relación Dosis-Respuesta a Droga , Dronabinol/análogos & derivados , Dronabinol/farmacología , Antagonismo de Drogas , Etanol/antagonistas & inhibidores , Ligandos , Ratones , Morfina/antagonistas & inhibidores , Piperidinas , Pirazoles , Rimonabant , Estadísticas no Paramétricas
16.
Brain Res ; 1110(1): 144-9, 2006 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-16860781

RESUMEN

We studied the involvement of endogenous ORL1 (NOP) receptors in the anxiety state. In mice selected as "anxious" and "non-anxious", ORL1 (NOP) receptor has been analysed by means of two autoradiographic approaches: [3H]nociceptin binding and nociceptin-stimulated [35S]GTPgammaS binding. We show that differences in anxiety state are associated with differences in G protein coupling efficiency of ORL1 (NOP) receptor in the nucleus accumbens, without any change in the density of the receptors.


Asunto(s)
Proteínas de Unión al GTP/metabolismo , Núcleo Accumbens/metabolismo , Receptores Opioides/metabolismo , Animales , Ansiedad , Autorradiografía/métodos , Conducta Animal , Modelos Animales de Enfermedad , Guanosina 5'-O-(3-Tiotrifosfato)/farmacocinética , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Ratones , Núcleo Accumbens/efectos de los fármacos , Péptidos Opioides/farmacocinética , Isótopos de Fósforo/farmacocinética , Tritio/farmacocinética , Receptor de Nociceptina , Nociceptina
17.
Pharmacol Biochem Behav ; 84(1): 43-50, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16733065

RESUMEN

Sensation seeking is frequently observed among drug addicts. This behaviour has been modelled in non-primate animals as novelty seeking. We previously determined that novelty preference did not predict amphetamine-induced place conditioning but was positively correlated with the consumption of a low concentrated amphetamine solution. Here, we studied the relationship between novelty seeking and the vulnerability to rewarding and reinforcing effects of morphine. Wistar rats were selected according to their novelty preference. In this model, animals have free choice between a new compartment and a "familiar" compartment to which they were previously exposed during two 30-min sessions, 24 h apart. We measured oral morphine consumption when this drug was presented in tap water (25 or 50 mg/l) in free choice with water or when it was presented (50 mg/l) in a 5% (w/v) sucrose solution in free choice with a sucrose solution. The oral consumption of quinine was also measured. The rewarding effect of morphine (1.25 and 5 mg/kg; i.p.) was determined in a conditioned place preference paradigm. Whereas high and low novelty seekers did not differ in reactivity to the aversive taste of quinine, preference for novelty was associated with a greater oral morphine consumption as well as an increased conditioned place preference induced by the 5 mg/kg dose of morphine. The present results support the hypothesis that novelty preference predisposes to drug abuse.


Asunto(s)
Conducta Animal/efectos de los fármacos , Morfina/farmacología , Administración Oral , Animales , Masculino , Morfina/administración & dosificación , Quinina/administración & dosificación , Ratas , Ratas Wistar
18.
Dev Biol ; 291(1): 53-66, 2006 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-16413525

RESUMEN

The Suppressor of fused (Su(fu)) protein is known to be a negative regulator of Hedgehog (Hh) signal transduction in Drosophila imaginal discs and embryonic development. It is antagonized by the kinase Fused (Fu) since Su(fu) null mutations fully suppress the lack of Fu kinase activity. In this study, we overexpressed the Su(fu) gene in imaginal discs and observed opposing effects depending on the position of the cells, namely a repression of Hh target genes in cells receiving Hh and their ectopic expression in cells not receiving Hh. These effects were all enhanced in a fu mutant context and were suppressed by cubitus interruptus (Ci) overexpression. We also show that the Su(fu) protein is poly-phosphorylated during embryonic development and these phosphorylation events are altered in fu mutants. This study thus reveals an unexpected role for Su(fu) as an activator of Hh target gene expression in absence of Hh signal. Both negative and positive roles of Su(fu) are antagonized by Fused. Based on these results, we propose a model in which Su(fu) protein levels and isoforms are crucial for the modulation of the different Ci states that control Hh target gene expression.


Asunto(s)
Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiología , Drosophila/metabolismo , Proteínas Represoras/metabolismo , Transducción de Señal , Animales , Proteínas de Unión al ADN/metabolismo , Drosophila/embriología , Proteínas de Drosophila/genética , Embrión no Mamífero/metabolismo , Ojo/embriología , Ojo/metabolismo , Femenino , Regulación del Desarrollo de la Expresión Génica , Proteínas Hedgehog , Masculino , Mutación , Fosforilación , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Represoras/genética , Factores de Transcripción/metabolismo , Alas de Animales/embriología , Alas de Animales/metabolismo
19.
Science ; 308(5729): 1758-62, 2005 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-15890843

RESUMEN

Polyglutamylation of tubulin has been implicated in several functions of microtubules, but the identification of the responsible enzyme(s) has been challenging. We found that the neuronal tubulin polyglutamylase is a protein complex containing a tubulin tyrosine ligase-like (TTLL) protein, TTLL1. TTLL1 is a member of a large family of proteins with a TTL homology domain, whose members could catalyze ligations of diverse amino acids to tubulins or other substrates. In the model protist Tetrahymena thermophila, two conserved types of polyglutamylases were characterized that differ in substrate preference and subcellular localization.


Asunto(s)
Dominio Catalítico , Péptido Sintasas/química , Péptido Sintasas/metabolismo , Ácido Poliglutámico/química , Ácido Poliglutámico/metabolismo , Tetrahymena thermophila/enzimología , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Sitios de Unión , Encéfalo/enzimología , Cilios/fisiología , Humanos , Ratones , Microtúbulos/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Movimiento , Péptido Sintasas/genética , Péptido Sintasas/aislamiento & purificación , Filogenia , Ácido Poliglutámico/genética , Ácido Poliglutámico/aislamiento & purificación , Conformación Proteica , Subunidades de Proteína/química , Subunidades de Proteína/aislamiento & purificación , Subunidades de Proteína/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Especificidad por Sustrato , Tetrahymena thermophila/genética , Tetrahymena thermophila/metabolismo , Tubulina (Proteína)/genética , Tubulina (Proteína)/aislamiento & purificación
20.
Alcohol Clin Exp Res ; 29(3): 378-88, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15770113

RESUMEN

BACKGROUND: Depression is frequently observed in drug abusers. However, depression may be a primary factor of predisposition to drug abuse or a consequence of drug abuse. The aim of this study was to analyze the influence of a preexisting depressive-like state/helplessness on subsequent alcohol responsiveness in mice. METHODS: Male and female CD1 mice were selected according to their immobility time in the tail suspension test, and only mice with "high immobility" and "low immobility" time were retained. Using a two-bottle free-choice paradigm, these mice were given continuous access to tap water or solutions of ethanol (3-20% v/v), quinine (12.5-50 mg/liter), or sucrose (1-4% w/v). In female mice, rewarding and aversive effects of ethanol (1.5 and 3 g/kg, intraperitoneally) were also investigated using the conditioned place preference and the conditioned taste aversion paradigms. RESULTS: Female mice were more immobile and drank more ethanol than male mice. No striking sex difference was observed in quinine consumption. Sucrose intake was higher in female than in male mice, whatever the solution concentration. At the 4% concentrated solution, a sucrose-induced increase in daily fluid intake was observed only in female mice. Female mice with high immobility time (HI) consumed more ethanol at the highest concentration than female mice with low immobility time (LI), whereas no difference was observed between HI and LI male mice. Moreover, whereas LI female mice failed to express place conditioning induced by the 3-g/kg dose of ethanol, HI female mice were strongly responsive to the rewarding effect of this high ethanol dose. Ethanol dose-dependently induced a conditioned taste aversion with a similar magnitude in both LI and HI female mice. CONCLUSIONS: The findings indicate that female CD1 mice tend to drink greater amounts of ethanol or sucrose solutions than male CD1 mice, suggesting that female mice may be a better model of excessive alcohol intake. Furthermore, no relationship was found between immobility scores and ethanol consumption in male mice. On the contrary, within female mice, HI mice consumed higher amounts of ethanol than LI mice probably because they experienced greater rewarding effects of ethanol. The present results support the hypothesis that depressive-like responses may predispose to ethanol abuse in female mice.


Asunto(s)
Consumo de Bebidas Alcohólicas/psicología , Depresores del Sistema Nervioso Central/farmacología , Condicionamiento Operante/efectos de los fármacos , Etanol/farmacología , Desamparo Adquirido , Suspensión Trasera/fisiología , Animales , Depresores del Sistema Nervioso Central/sangre , Relación Dosis-Respuesta a Droga , Etanol/sangre , Femenino , Hipotermia/inducido químicamente , Ratones , Actividad Motora/fisiología , Recompensa , Gusto/efectos de los fármacos
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