Steven Engelen

Sucrose (Suc) synthase (Sus) is the major enzyme of Suc breakdown for cellulose biosynthesis in cotton (Gossypium hirsutum) fiber, an important source of fiber for the textile industry. This study examines the tissue-specific expression, relative abundance, and temporal expression of various Sus transcripts and proteins present in cotton. A novel isoform of Sus (SusC) is identified that is expressed at high levels during secondary cell wall synthesis in fiber and is present in the cell wall fraction. The phylogenetic relationships of the deduced amino acid sequences indicate two ancestral groups of Sus proteins predating the divergence of monocots and dicots and that SusC sequences form a distinct branch in the phylogeny within the dicot-specific clade. The subcellular location of the Sus isoforms is determined, and it is proposed that cell wall-localized SusC may provide UDP-glucose for cellulose and callose synthesis from extracellular sugars.

Objective To assess the clinically optimal tibolone dose for the relief of climacteric complaints. Design A randomised, double blind, placebo‐controlled trial. Setting Twenty‐eight centres in Norway, The Netherlands, Sweden and Finland. Population Seven hundred and seventy‐five healthy postmenopausal women were randomised to tibolone in a daily dose of 0.625, 1.25, 2.5 or 5.0 mg or placebo for 12 weeks. Methods At baseline, and after 4, 8 and 12 weeks, hot flushes, sweating, vaginal bleeding and adverse experiences were recorded. Main outcome measures Change in frequency and intensity of hot flushes and sweating over 12 weeks. Results From week four onwards, 2.5 and 5.0 mg tibolone were significantly more effective than placebo, regarding the frequency of hot flushes and sweating ( P < 0.001 ), whereas the 0.625 mg dose was not significantly different from placebo during the study. The frequency of hot flushes with the 1.25 mg dose was statistically significantly different from placebo, only from week eight onwards. The incidence of dropouts due to insufficient therapeutic effect was much higher in the tibolone 1.25 mg group (9.5%) than in the 2.5 (1.9%) and 5.0 mg (1.3%) groups. A dose‐related increase in incidence of vaginal bleeding or spotting was observed ( P < 0.0001 ). Bleeding incidence in the 5.0 mg dose group was about twice as high as in the 2.5 mg dose group. There was no difference in incidence of adverse experiences between the 2.5‐ and the 1.25 mg dose group. Conclusion A daily dose of 2.5 mg tibolone is the clinically optimal dose for the treatment of climacteric complaints in postmenopausal women.