The incidence of myelodysplastic syndromes in Western Greece is increasing.

Descriptive epidemiology of the myelodysplastic syndromes (MDS) is always interesting and may reveal time-dependent and geographical variations, as well as occupational exposure. Epidemiological data in Greece are not available by now. We have collected and analyzed medical records of all patients with a documented diagnosis of MDS, performed by an expert hematologist and/or hematopathologist, in the geographical area of Western Greece, during the 20-year period, defined between 1990 and 2009. We have then calculated and described demographic and clinical features of the diagnosed MDS patient population, and assessed the incidence and prevalence rates of MDS in Western Greece, during the above-mentioned period. A total of 855 patients with newly diagnosed MDS have been identified. Refractory anemia was the most common subtype in both FAB and WHO classification systems and in both genders. Del-5q and RARS were more commonly encountered among females, and the dysplastic subtype of chronic myelomonocytic leukemia among males. Trisomy 8 was the most common single cytogenetic abnormality. The crude mean annual incidence rate of MDS was 6.0 per 100,000 inhabitants aged ≥15 years old (all subtypes according to FAB), and it was 4.8 per 100,000 when CMML and RAEB-T were excluded. Crude incidence rate was higher in rural than in urban areas, but this finding was not confirmed after age standardization. Age-standardized mean annual incidence rate in men was 7.9/100,000 and in women 3.4/100,000. A continuously increasing incidence rate of MDS has been observed throughout the study period.

Acid-catalyzed cyclization of terpenes under homogeneous and heterogeneous conditions as probed through stereoisotopic studies: a concerted process with competing preorganized chair and boat transition states.

Based on stereoisotopic studies and beta-secondary isotope effects, we propose that the acid-catalyzed cyclization of geranyl acetate proceeds through a concerted mechanism. Under heterogeneous conditions (zeolite Y confinement), a preorganized chairlike transition state predominates, whereas under homogeneous conditions the boat- and chairlike transition states are almost isoenergetic. For the case of farnesyl acetate, we propose that under homogeneous conditions a concerted dicyclization occurs with a preorganized boat-chair transition state competing with the chair-chair transition state. Under zeolite confinement conditions, the chair-chairlike dicyclization transition state is highly favorable. The preference of chairlike transition states within the cavities of zeolite Y is attributed to a transition state shape selectivity effect.

Divergent synthesis of the co-isolated mycotoxins longianone, isopatulin, and (Z)-ascladiol via furan oxidation.

Longianone and the biosynthetically related mycotoxins isopatulin and (Z)-ascladiol were prepared following a divergent route from a readily available furan diol. The route toward longianone features an unprecedented TBAF-promoted intramolecular oxa-Michael reaction to a conjugated keto enoate, and the oxidation of dihydrolongianone to longianone with stabilized IBX. The route to isopatulin features a chemoenzymatic synthesis of (Z)-ascladiol, and the regioselective oxidation of (Z)-ascladiol to isopatulin with MnO(2).

Selective isomerization of epoxides to allylic alcohols catalyzed by TiO2-supported gold nanoparticles.

ReacTiO(2)ns for rings: Gold nanoparticles supported on TiO(2) are used as a novel heterogeneous catalyst for the isomerization of epoxides to allylic alcohols by a concerted mechanism (see scheme). The reaction proceeds in high yields and the product selectivity is often remarkable.

Selective monocyclization of epoxy terpenoids promoted by zeolite NaY. A short biomimetic synthesis of elegansidiol and farnesiferols B-D.

Epoxy terpenes cyclize readily, by confinement within zeolite NaY, to form exomethylenic cyclohexanols as the major products. The selective monocyclization of 10,11-epoxyfarnesyl acetate within NaY provides a short and efficient biomimetic route to (+/-)-elengasidiol and (+/-)-farnesiferols B-D. [reaction: see text].

Cyclization of 1,6-enynes catalyzed by gold nanoparticles supported on TiO2: significant changes in selectivity and mechanism, as compared to homogeneous Au-catalysis.

Gold nanoparticles supported on TiO(2) (1.2 mol %) catalyze, for the first time under heterogeneous conditions, the cycloisomerization of a series of 1,6-enynes in high yields. In several cases, the product selectivity differs significantly as compared to homogeneous Au(I)-catalysis. Based on product analysis and stereoisotopic studies it is proposed that the major or exclusive pathway involves a 5-exo cyclization mode to form stereoselectively gold cyclopropyl carbenes that undergo a single cleavage pathway, in contrast to homogeneous Au-catalysis where the double cleavage pathway operates substantially.