Influences of polymorphic variants of DRD2 and SLC6A3 genes, and their combinations on smoking in Polish population

<p>Abstract</p> <p>Background</p> <p>Polymorphisms in dopaminergic genes may influence cigarette smoking by their potential impact on dopamine reward pathway function. <it>A1 </it>allele of <it>DRD2 </it>gene is associated with a reduced dopamine D2 receptor density, and it has been hypothesised that <it>A1 </it>carriers are more vulnerable to smoking. In turn, the 9-repeat allele of dopamine transporter gene (<it>SLC6A3</it>) has been associated with a substantial reduction in dopamine transporter, what might result in the higher level of dopamine in the synaptic cleft, and thereby protective role of this allele from smoking. In the present study we investigated whether polymorphic variants of <it>DRD2 </it>and <it>SLC6A3 </it>genes and their combinations are associated with the smoking habit in the Polish population.</p> <p>Methods</p> <p>Genotyping for <it>Taq</it>I<it>A </it>polymorphism of <it>DRD2 </it>and <it>SLC6A3 </it>VNTR polymorphism was performed in 150 ever-smokers and 158 never-smokers. The association between the smoking status and smoking phenotypes (related to the number of cigarettes smoked daily and age of starting regular smoking), and genotype/genotype combinations was expressed by ORs together with 95% CI. Alpha level of 0.05, with Bonferroni correction whenever appropriate, was used for statistical significance.</p> <p>Results</p> <p>At the used alpha levels no association between <it>DRD2 </it>and <it>SLC6A</it>3 genotypes and smoking status was found. However, <it>A1 </it>allele carriers reported longer abstinence periods on quitting attempts than non-carriers (p = 0.049). The ORs for heavier smoking were 0.38 (0.17-0.88), p = 0.023, and 0.39 (0.17-0.88), p = 0.021 in carriers compared to non-carriers of <it>A1 </it>or <it>*9 </it>allele, respectively, and the OR for this smoking phenotype was 8.68 (2.47-30.46), p = 0.0005 for the <it>A1</it>-/<it>9</it>- genotype combination, relatively to the <it>A1</it>+/<it>9</it>+. Carriers of <it>*9 </it>allele of <it>SLC6A3 </it>had over twice a lower risk to start smoking before the age of 20 years compared to non-carriers (sex-adjusted OR = 0.44; 95% CI: 0.22-0.89; p = 0.0017), and subjects with <it>A1-/9- </it>genotype combination had a higher risk for staring regular smoking before the age of 20 years in comparison to subjects with <it>A1+/9+ </it>genotype combination (sex-adjusted OR = 3.79; 95% CI:1.03-13.90; p = 0.003).</p> <p>Conclusion</p> <p>Polymorphic variants of <it>DRD2 </it>and <it>SLC6A3 </it>genes may influence some aspects of the smoking behavior, including age of starting regular smoking, the level of cigarette consumption, and periods of abstinence. Further large sample studies are needed to verify this hypothesis.</p

Mycoplasmal mastitis in dairy herds

This paper addresses two main issues of the DOK system [15], that is the design of a framework for enforcing security policies and a secure architecture which implements such a framework. Federated security policies are expressed as logic-based expressions (called &quot;aggregation constraints&quot;) specifying the different combinations of transactions that a user is not allowed to issue, either in single or multiple states of a federation. To enable efficient monitoring of aggregation constraints, state transition graphs are generated to model the different sub-computations of the constraints. Two marking techniques, namely LMT (Linear Marking Technique) and ZMT (Zigzag Marking Technique), are proposed to detect violations of federated security policies. To enable an effective enforcement of security policies, we designed a secure DOK architecture using specialised agents: (i) coordination agents allow the coordination of different federated activities, (ii) task agents perform specific tasks of th..