317 research outputs found

    The geographic distribution of the ACE II genotype: a novel finding

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    Association between the Val66Met polymorphism (rs6265/G196A) of the BDNF gene and cognitive performance with SSRI use in Arab Alzheimer’s disease patients

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    Brain derived neutrophic factor (BDNF) is a protein and a member of the neurotrophin family of growth factors, supports the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses. The BDNF gene Val66Met polymorphism (rs6265/G196A) is responsible for BDNF synthesis that impact BDNF function that includes memory and cognition. This study investigated whether the BDNF gene Val66Met polymorphism (rs6265/G196A) is associated with cognitive function changes in both Alzheimer disease (AD) patients and elderly participants. In addition the impact of SSRI use on cognition improvement will be assessed. Healthy young, middle ages (25–59 years old) and elderly (more than 60 years old) participants (140) as well as 40 AD patients of whom are both of Saudi Arabian origin were recruited. The genotyping for the association study was performed by real-time PCR using Taqman chemistry in the ABI Prism 7900HT Sequence Detection System. Both Mini-Mental Status Examination (MMSE) and Clinical Dementia Rating (CDR) were used to assess cognitive function of healthy and AD participants, respectively. The findings showed that the BDNF Val66Met genotype distributions and allele frequencies have significant association with cognitive performance in both elderly control group and AD patients. The main findings showed that carriers of GG homozygotes (Val/Val) have superior cognitive performance among AD patients and elderly control subjects. In addition the use of SSRIs in 13 AD patients and 17 elderly participants positively improved cognitive function in elderly (p > 0.001) but not in AD patients (p = 0.1)

    Scientific U-turns: eight occasions when science changed its mind

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    The Scientific Method is the series of processes by which hypotheses, ideas and theories are shown to be true beyond a reasonable scientific doubt. Most science ‘fact’ is expressed in terms of probabilities rather than certainties. Thus, by means of statistical calculations, researchers aim to determine whether an observed association between two events or characteristics may have occurred by chance (coincidence), whether they frequently occur together (correlation) or whether they occur together because one causes the other (causative relationship). In this article we review the Scientific Method and consider the statistical tests that are applied. We then focus on the occasions when science changes its mind and review eight such occurrences

    Changes of renin-angiotensin system-related aminopeptidases in early stage Alzheimer's disease

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    Activities of aminopeptidases A, B, and N (ApA, ApB & ApN) and insulin-regulated aminopeptidase (IRAP) have been seen to be decreased amongst patients with Alzheimer's disease (AD). All of these enzymes are involved with the brain renin-angiotensin system which is believed to be involved with learning and memory. This study aimed to explore the time course and the mechanisms underlying these changes. Serum samples were collected from 45 AD patients at the start of the study, and again 13 months later (n = 37). The control group was 22 healthy, older, adults. Enzyme activity was determined at two substrate concentrations to allow Michaelis-Menten analysis of the enzyme activity. The results indicated that there was decreased activity of ApA, ApB and ApN amongst AD patients but no difference in serum IRAP activity. There were no associations between enzyme activity and age, gender nor scores on psychomotor tests. Consideration of the data for the two time points for AD patients showed that the changes in ApB occurred at an early stage of the disease and persisted, whilst those of ApA and ApN only became apparent at later stages of the disease. Although differences in Michaelis-Menten parameters were not statistically significant, consideration of the values suggested that the decrease in ApB activity may be a result of changes in enzyme protein conformation, whilst that of ApN may be a consequence of decreased enzyme expression. Importantly, the different time courses of the effects and the differential changes in enzyme affinity and expression indicated that the observed changes with progression of AD were not a ‘class effect’ for serum aminopeptidases but were idiosyncratic for the individual enzymes

    Pharmacist awareness and views towards counterfeit medicine in Lebanon

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    Background:  Pharmacists, as healthcare professionals, have patients’ well-being and safety as their primary concern. However, the safety and efficacy of treatments may be compromised by the availability of counterfeit medicine (CFM) which could have serious consequences for public health. Objectives: To assess pharmacist awareness and views towards CFM in Lebanon. Methods: The study used convenience sampling and selected pharmacists based on their willingness to participate and used a questionnaire as a tool to determine their experiences and views towards CFM. The questionnaires were completed in different regions in Lebanon. Key findings: A total of 223 pharmacists participated in the study, and all were able to define CFM, however were inconsistent in their definitions. The majority reported identifying CFM by the medicine’s effect (67.7%), followed by cost (66.8%). Almost 43% reported knowing of pharmacists who dispensed CFM. Additionally, participants reported that they believed that pharmacists who dealt with CFM were unprofessional (89.2%) and unethical (86.5%), and that they did it for the ‘easy money’ (87.9%) and large profit (86.5%). Conclusion: The study highlighted the need for additional CFM awarenesscampaigns with an emphasis on the role that pharmacists have in protecting patients from using CFM. In addition, there is a need for an official CFM definition that distinguishes between the different types of counterfeiting. Furthermore, the Lebanese Ministry of Public Health and regulatory authorities should control and secure the supply chain of medicine in the country and enforce the law

    Performance monitoring in nicotine dependence: considering integration of recent reinforcement history

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    INTRODUCTION: Impaired monitoring of errors and conflict (performance monitoring; PM) is well documented in substance dependence (SD) including nicotine dependence and may contribute to continued drug use. Contemporary models of PM and complementary behavioural evidence suggest that PM works by integrating recent reinforcement history rather than evaluating individual behaviours. Despite this, studies of PM in SD have typically used indices derived from reaction to task error or conflict on individual trials. Consequently impaired integration of reinforcement history during action selection tasks requiring behavioural control in SD populations has been underexplored. METHODS: A reinforcement learning task assessed the ability of abstinent, satiated, former and never smokers (N=60) to integrate recent reinforcement history alongside a more typical behavioural index of PM reflecting the degree of reaction time slowing following an error (post-punishment slowing; PPS). RESULTS: On both indices there was a consistent pattern in PM data: Former smokers had the greatest and satiated smokers the poorest PM. Specifically satiated smokers had poorer reinforcement integration than former (p=0.005) and never smokers (p=0.041) and had less post-punishment slowing than former (p<0.001), never (p=0.003) and abstinent smokers (p=0.026). CONCLUSIONS: These are the first data examining the effects of smoking status on PM that use an integration of reinforcement history metric. The concordance of the reinforcement integration and PPS data suggest that this could be a promising method to interrogate PM in future studies. PM is influenced by smoking status. As PM is associated with adapting behaviour, poor PM in satiated smokers may contribute towards continued smoking despite negative consequences. Former smokers show elevated PM suggesting this may be a good relapse prevention target for individuals struggling to remain abstinent however prospective and intervention studies are needed. A better understanding of PM deficits in terms of reinforcement integration failure may stimulate development of novel treatment approaches
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