2,157 research outputs found
MSc, PhD theses and scientific papers, on the subject of field crops biotechnology in Turkey
Eurobiotech Agriculture Symposium -- APR 12-14, 2012 -- Erciyes Univ, Kayseri, TURKEYWOS: 000318064700042âŠEuropean Biotechnol Themat Network Asso
Intravenous selfâadministration studies with l âdeprenyl (selegiline) in monkeys *
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110034/1/cptclpt1994208.pd
Effects of Endocannabinoid System Modulation on Cognitive and Emotional Behavior
Cannabis has long been known to produce cognitive and emotional effects. Research has shown that cannabinoid drugs produce these effects by driving the brainâs endogenous cannabinoid system and that this system plays a modulatory role in many cognitive and emotional processes. This review focuses on the effects of endocannabinoid system modulation in animal models of cognition (learning and memory) and emotion (anxiety and depression). We review studies in which natural or synthetic cannabinoid agonists were administered to directly stimulate cannabinoid receptors or, conversely, where cannabinoid antagonists were administered to inhibit the activity of cannabinoid receptors. In addition, studies are reviewed that involved genetic disruption of cannabinoid receptors or genetic or pharmacological manipulation of the endocannabinoid-degrading enzyme, fatty acid amide hydrolase (FAAH). Endocannabinoids affect the function of many neurotransmitter systems, some of which play opposing roles. The diversity of cannabinoid roles and the complexity of task-dependent activation of neuronal circuits may lead to the effects of endocannabinoid system modulation being strongly dependent on environmental conditions. Recent findings are reviewed that raise the possibility that endocannabinoid signaling may change the impact of environmental influences on emotional and cognitive behavior rather than selectively affecting any specific behavior
Reinforcing and neurochemical effects of cannabinoid CB1 receptor agonists, but not cocaine, are altered by an adenosine A2A receptor antagonist
Several recent studies suggest functional and molecular interactions between striatal adenosine A2A and cannabinoid CB1 receptors. Here, we demonstrate that A2A receptors selectively modulate reinforcing effects of cannabinoids. We studied effects of A2A receptor blockade on the reinforcing effects of deltaâ9âtetrahydrocannabinol (THC) and the endogenous CB1 receptor ligand anandamide under a fixedâratio schedule of intravenous drug injection in squirrel monkeys. A low dose of the selective adenosine A2A receptor antagonist MSXâ3 (1âmg/kg) caused downward shifts of THC and anandamide doseâresponse curves. In contrast, a higher dose of MSXâ3 (3âmg/kg) shifted THC and anandamide doseâresponse curves to the left. MSXâ3 did not modify cocaine or food pellet selfâadministration. Also, MSXâ3 neither promoted reinstatement of extinguished drugâseeking behavior nor altered reinstatement of drugâseeking behavior by nonâcontingent priming injections of THC. Finally, using in vivo microdialysis in freelyâmoving rats, a behaviorally active dose of MSXâ3 significantly counteracted THCâinduced, but not cocaineâinduced, increases in extracellular dopamine levels in the nucleus accumbens shell. The significant and selective results obtained with the lower dose of MSXâ3 suggest that adenosine A2A antagonists acting preferentially at presynaptic A2A receptors might selectively reduce reinforcing effects of cannabinoids that lead to their abuse. However, the appearance of potentiating rather than suppressing effects on cannabinoid reinforcement at the higher dose of MSXâ3 would likely preclude the use of such a compound as a medication for cannabis abuse. Adenosine A2A antagonists with more selectivity for presynaptic versus postsynaptic receptors could be potential medications for treatment of cannabis abuse
Modification of pharmacokinetic and abuse-related effects of cocaine by human-derived cocaine hydrolase in monkeys
Although substantial research effort has focused on developing pharmacological treatments for
cocaine abuse, no effective medications have been developed. Recent studies show that enzymes
that metabolize cocaine in the periphery, forestalling its entry into the brain, can prevent cocaine
toxicity and its behavioral effects in rodents. Here we report on effects of one such enzyme (Albu-
CocH) on the pharmacokinetic and behavioral effects of cocaine in squirrel monkeys. Albu-CocH
was developed from successive mutations of human butyrylcholinesterase (BChE) and has 1000-
fold greater catalytic activity against cocaine than naturally occurring BChE. Pharmacokinetic
studies showed that Albu-CocH (5 mg/kg) had a half-life of 56.6 hours in squirrel monkeys. In
these studies, plasma levels of cocaine following i.v. 1 mg/kg cocaine were reduced two hours
after administration of Albu-CocH, whereas plasma levels of the cocaine metabolite ecgonine
methyl ester were increased. These effects were still evident 72 hrs following Albu-CocH
administration. In behavioral experiments in monkeys, pretreatment with 5 mg/kg Albu-CocH
dramatically decreased self-administration of a reinforcing dose of i.v. cocaine (30 ÎŒg/kg/
injection) for over 24 hours. Pretreatment with 5 mg/kg Albu-CocH also attenuated the
reinstatement of extinguished cocaine self-administration by an i.v. priming injection of cocaine
(0.1 or 0.3 mg/kg) and, in separate studies, attenuated the discriminative stimulus effects of
cocaine. The ability of Albu-CocH to attenuate the abuse-related effects of cocaine in squirrel monkeys indicates that further investigation of BChE mutants as potential treatment for cocaine
abuse and toxicity is warranted.This research was supported in part by the Intramural Research Program of the NIH, National Institute on Drug
Abuse
Investigation of antihypertensive class, dementia, and cognitive decline: A meta-analysis
Objective High blood pressure is one of the main modifiable risk factors for dementia. However, there is conflicting evidence regarding the best antihypertensive class for optimizing cognition. Our objective was to determine whether any particular antihypertensive class was associated with a reduced risk of cognitive decline or dementia using comprehensive meta-analysis including reanalysis of original participant data.
Methods To identify suitable studies, MEDLINE, Embase, and PsycINFO and preexisting study consortia were searched from inception to December 2017. Authors of prospective longitudinal human studies or trials of antihypertensives were contacted for data sharing and collaboration. Outcome measures were incident dementia or incident cognitive decline (classified using the reliable change index method). Data were separated into mid and late-life (>65 years) and each antihypertensive class was compared to no treatment and to treatment with other antihypertensives. Meta-analysis was used to synthesize data.
Results Over 50,000 participants from 27 studies were included. Among those aged >65 years, with the exception of diuretics, we found no relationship by class with incident cognitive decline or dementia. Diuretic use was suggestive of benefit in some analyses but results were not consistent across follow-up time, comparator group, and outcome. Limited data precluded meaningful analyses in those â€65 years of age.
Conclusion Our findings, drawn from the current evidence base, support clinical freedom in the selection of antihypertensive regimens to achieve blood pressure goals.
Clinical trials registration The review was registered with the international prospective register of systematic reviews (PROSPERO), registration number CRD42016045454.The corresponding author is
funded by the Australian National Health and Medical Research Council, National Institute for Dementia Research,
and Dementia Centre for Research Collaboration (NHMRC
NNIDR DCRC)
Evaluation of the Effect of Systolic Blood Pressure and Pulse Pressure on Cognitive Function: The Women's Health and Aging Study II
Evidence suggests that elevated systolic blood pressure (SBP) and pulse pressure (PP) in midlife is associated with increased risk for cognitive impairment later in life. There is mixed evidence regarding the effects of late life elevated SBP or PP on cognitive function, and limited information on the role of female gender.Effects of SBPand PPon cognitive abilities at baseline and over a 9-year period were evaluated in 337 non-demented community-dwelling female participants over age 70 in the Women's Health and Aging Study II using logistic and Cox proportional hazards regression analyses. Participants aged 76-80 years with SBPâ„160 mmHg or PPâ„84 mmHg showed increased incidence of impairment on Trail Making Test-Part B (TMT, Part B), a measure of executive function, over time when compared to the control group that included participants with normal and pre-hypertensive SBP (<120 and 120-139 mmHg) or participants with low PP (<68 mmHg) (HRâ=â5.05 [95%CIâ=â1.42, 18.04], [HRâ=â5.12 [95%CIâ=â1.11; 23.62], respectively). Participants aged 70-75 years with PPâ„71 mmHg had at least a two-fold higher incidence of impairment on HVLT-I, a measure of verbal learning, over time when compared to participants with low PP (<68 mmHg) (HRâ=â2.44 [95%CIâ=â1.11, 5.39]).Our data suggest that elevated SBP or PP in older non-demented women increases risk for late-life cognitive impairment and that PP could be used when assessing the risk for impairment in cognitive abilities. These results warrant further, larger studies to evaluate possible effects of elevated blood pressure in normal cognitive aging
Analysis of the common genetic component of large-vessel vasculitides through a meta- Immunochip strategy
Giant cell arteritis (GCA) and Takayasu's arteritis (TAK) are major forms of large-vessel vasculitis (LVV) that share clinical features. To evaluate their genetic similarities, we analysed Immunochip genotyping data from 1,434 LVV patients and 3,814 unaffected controls. Genetic pleiotropy was also estimated. The HLA region harboured the main disease-specific associations. GCA was mostly associated with class II genes (HLA-DRB1/HLA-DQA1) whereas TAK was mostly associated with class I genes (HLA-B/MICA). Both the statistical significance and effect size of the HLA signals were considerably reduced in the cross-disease meta-analysis in comparison with the analysis of GCA and TAK separately. Consequently, no significant genetic correlation between these two diseases was observed when HLA variants were tested. Outside the HLA region, only one polymorphism located nearby the IL12B gene surpassed the study-wide significance threshold in the meta-analysis of the discovery datasets (rs755374, P?=?7.54E-07; ORGCA?=?1.19, ORTAK?=?1.50). This marker was confirmed as novel GCA risk factor using four additional cohorts (PGCA?=?5.52E-04, ORGCA?=?1.16). Taken together, our results provide evidence of strong genetic differences between GCA and TAK in the HLA. Outside this region, common susceptibility factors were suggested, especially within the IL12B locus
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