No description available.

No description available.

No description available.

No description available.

UDP-glucose, the precursor for cellulose biosynthesis, can be produced via the catalysis of sucrose by sucrose synthase (SuSy) or through the phosphorylation of glucose-I-phosphate by UDP-glucose pyrophosphorylase (UGPase). As such, these genes, together with sucrose phosphate synthase (SPS) which recycles fructose (an inhibitor of SuSy), are interesting targets for altering carbon allocation in plants. In an attempt to alter cell wall biosynthesis in plants, targeted overexpression of SuSy, UGPase and SPS independently and in a pyramiding strategy was assessed in tobacco. All lines displayed enhanced growth and biomass production, and in the case of double and triple transgenics, there was an additive effect. Despite the increased growth rates, there was no consistent change in soluble carbohydrate pools. Furthermore, only the triple transgenics had constant changes in structural carbohydrates: with increased hemicellulose content and slight increases in cellulose. Collectively, these results support the role of SPS, SuSy and UGPase in maintaining sink strength, but suggest that the reallocation of carbon to cellulose production in tobacco may not be possible by overexpressing these genes. In contrast, transgenic poplar overexpressing UGPase produced significantly more cellulose than wild-type trees. However, this was accompanied by a severe reduction in growth and the production of a salicylic acid glucoside (SAG) in significant quantities. The UDP-glucose generated by UGPase overexpression appeared to participate in both the synthesis of cellulose and SAG, suggesting that cellulose biosynthesis may be limited by the cellulose synthase complex. Poplar transformed with SuSy and with SuSy x UGPase also had increased cellulose production. The trees were phenotypically normal, with only minor reductions in height growth in some lines. It appears that UDP-glucose may be channelled directly to the cellulose synthase complex by SuSy. The increased cellulose content was associated with an increase in cell wall crystallinity, but there was no change in microfibril angle, confirming the re-allocation to cellulose synthesis was not the result of tension wood formation, again supporting the hypothesis that the cellulose synthase complex is the limiting factor. Clearly, it is possible to alter cellulose deposition in trees by augmenting sucrose metabolism to produce UDP-glucose, the precursor to cellulose biosynthesis.

This cross-sectional study examines data from the 2008-2009 Youth Smoking Survey among never, current and former smoking grade 9-12 students using logistic regression. Path analysis examining correlates of former from current smoking was conducted for females and males. Former smokers represent a distinct, often intermediary, group of students between current and never smokers. Former smokers have similarities with current smokers on individual factors but more closely resemble never smokers on social and environmental factors. Among females, social factors were most influential; whereas environmental and individual factors played more of a role in male smoking cessation. These results further describe youth who quit smoking. The strong effects from social factors suggest the importance of family and peer support for quitting. These findings inform the development of youth cessation programming by providing a target profile and highlighting areas for intervention focus.

No description available.

No description available.

A method was developed for rapid plant regeneration from protoplasts of birdsfoot trefoil (Lotus corniculatus cv. Leo) using in vitro cotyledons and a new enzyme formula. Protoplasts of a transgenic Nicotiana tabacum cv. Xanthi line KCR were isolated from leaves, in vitro shoots, and calli by an enzyme formula consisting of 0.5 % Cellulase R-10 and 0.05 % Pectolyase Y23 with either 0.4 M sucrose or 0.5 M mannitol as the osmoticum. Nine asymmetric fusion experiments were conducted between iodoacetate inactivated birdsfoot trefoil and irradiated transgenic tobacco protoplasts. The fusion products underwent several divisions but no visible colonies were obtained. Resistance analyses revealed the inactivation of the herbicide resistant gene in the transgenic tobacco calli. A putative chlorsulfuron resistant line has been obtained by in vitro selection from birdsfoot trefoil cotyledonous protoplasts. Their regenerants had normal ploidy, and expressed improved tolerance when sprayed with chlorsulfuron at the rate of 30 g/ha.

Chronic pain and tobacco dependence are two highly prevalent and comorbid conditions. The rate of smoking among persons in pain may be greater than twice the rate observed in the general population. Smokers tend to experience more adverse pain-treatment outcomes than do nonsmokers, and there is mounting evidence to suggest that smokers with comorbid pain disorders may have more difficulty abstaining from tobacco. The main goal of the current study was to examine cross-sectional relations between chronic pain status and past use of pharmacotherapy for smoking cessation. We also tested associations between chronic pain status and frequency of past quit attempts. Data were derived from a nationally-representative survey of households in the continental United States. After adjusting for sociodemographic factors, substance use, mood and anxiety disorders, and number of attempts to quit smoking, smokers with chronic pain were found to be 1.67 times more likely to endorse past use of pharmacotherapy for smoking cessation, relative to smokers with no chronic pain. Chronic pain status was not associated with number of past attempts to quit smoking. These data suggest that smokers with chronic pain are motivated to quit smoking, and may be particularly amenable to pharmacologic intervention. Results are discussed with regard to clinical implications and directions for future research.