Use of plan quality degradation to evaluate tradeoffs in delivery efficiency and clinical plan metrics arising from IMRT optimizer and sequencer compromises

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135043/1/mp8118.pd

Two Origins for the Gene Encoding α-Isopropylmalate Synthase in Fungi

BACKGROUND: The biosynthesis of leucine is a biochemical pathway common to prokaryotes, plants and fungi, but absent from humans and animals. The pathway is a proposed target for antimicrobial therapy. METHODOLOGY/PRINCIPAL FINDINGS: Here we identified the leuA gene encoding alpha-isopropylmalate synthase in the zygomycete fungus Phycomyces blakesleeanus using a genetic mapping approach with crosses between wild type and leucine auxotrophic strains. To confirm the function of the gene, Phycomyces leuA was used to complement the auxotrophic phenotype exhibited by mutation of the leu3+ gene of the ascomycete fungus Schizosaccharomyces pombe. Phylogenetic analysis revealed that the leuA gene in Phycomyces, other zygomycetes, and the chytrids is more closely related to homologs in plants and photosynthetic bacteria than ascomycetes or basidiomycetes, and suggests that the Dikarya have acquired the gene more recently. CONCLUSIONS/SIGNIFICANCE: The identification of leuA in Phycomyces adds to the growing body of evidence that some primary metabolic pathways or parts of them have arisen multiple times during the evolution of fungi, probably through horizontal gene transfer events

Status Update and Interim Results from the Asymptomatic Carotid Surgery Trial-2 (ACST-2)

Objectives: ACST-2 is currently the largest trial ever conducted to compare carotid artery stenting (CAS) with carotid endarterectomy (CEA) in patients with severe asymptomatic carotid stenosis requiring revascularization. Methods: Patients are entered into ACST-2 when revascularization is felt to be clearly indicated, when CEA and CAS are both possible, but where there is substantial uncertainty as to which is most appropriate. Trial surgeons and interventionalists are expected to use their usual techniques and CE-approved devices. We report baseline characteristics and blinded combined interim results for 30-day mortality and major morbidity for 986 patients in the ongoing trial up to September 2012. Results: A total of 986 patients (687 men, 299 women), mean age 68.7 years (SD ± 8.1) were randomized equally to CEA or CAS. Most (96%) had ipsilateral stenosis of 70-99% (median 80%) with contralateral stenoses of 50-99% in 30% and contralateral occlusion in 8%. Patients were on appropriate medical treatment. For 691 patients undergoing intervention with at least 1-month follow-up and Rankin scoring at 6 months for any stroke, the overall serious cardiovascular event rate of periprocedural (within 30 days) disabling stroke, fatal myocardial infarction, and death at 30 days was 1.0%. Conclusions: Early ACST-2 results suggest contemporary carotid intervention for asymptomatic stenosis has a low risk of serious morbidity and mortality, on par with other recent trials. The trial continues to recruit, to monitor periprocedural events and all types of stroke, aiming to randomize up to 5,000 patients to determine any differential outcomes between interventions. Clinical trial: ISRCTN21144362. © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved

One molecule of molybdopterin guanine dinucleotide is associated with each subunit of the heterodimeric Mo-Fe-S protein transhydroxylase of Pelobacter acidigallici as determined by SDS/RAGE and mass spectrometry

The molybdenum-containing iron-sulfur protein 1,2,3,5-tetrahydroxybenzene:1,2,3-trihydroxyben-zene hydroxyltransferase (transhydroxylase) of Pelobacter acidigallici was investigated by various techniques including mass spectrometry and electron paramagnetic resonance. Mass spectrometry confirmed that the 133-kDa protein is a heterodimer consisting of an α subunit (100.4 kDa) and a β subunit (31.3 kDa). The presence of a molybdenum cofactor was documented by fluorimetric analysis of the oxidized form A of molybdopterin. The enzyme contained 1.55 ± 0.14 mol pterin and 0.92 ± 0.25 mol molybdenum/mol enzyme (133 kDa). Alkylation of the molybdenum cofactor with iodoacetamide formed di(carboxamidomethyl)-molybdopterin. Upon acid hydrolysis, 1.4 mol 5'GMP/mol enzyme (133 kDa) was released indicating that molybdenum is bound by a molybdopterin guanine dinucleotide. The α and β subunits were separated by preparative gel electrophoresis. Both subunit fractions were free of molybdenum but contained equal amounts of a fluorescent form of the molybdenum cofactor. Mass spectrometry at various pH values revealed that an acid-labile cofactor was released from the large subunit and also from the small subunit. At X-band, 5 25 K, transhydroxylase (as isolated) showed minor EPR resonances with apparent g values around 4.3, 2.03 and, depending on the preparation, a further signal at g of approximately 1.98. This signal was still detectable above 70 K and was attributed to a Mo(V) center. Upon addition of dithionite, a complex set of intense resonances appeared in the region g 2.08 1.88. From their temperature dependence, three distinct sites could be identified: the Fe-S center I with gx,y,z at approximately 1.875, 1.942 and 2.087 (gav 1.968, detectable 20K); and the Mo(V) center consisting of a multiple signal around g 1.98 (detectable >70 K)

Cloning and expression analysis of beta-isopropylmalate dehydrogenase from potato

A full-length cDNA clone for β-isopropylmalate dehydrogenase from potato has been isolated and sequenced. The open reading frame is 1071 by in length encoding a protein of 357 amino acids which includes a 29 amino acid, putative chloroplastic transit peptide. The amino acid sequence shows 33.3% and 28.6% identity to β-isopropylmalate dehydrogenases from rape and Bacillus subtilis, respectively. Southern analysis shows that the gene is present in low copy number in potato, and in single copy in tomato and Arabidopsis. The gene is expressed in all tissues of the potato plant and its expression is increased by leucine, and leucine plus threonine, in contrast to the situation in yeast and prokaryotes. The gene is also induced by sucrose in a manner similar to that seen with genes involved in carbohydrate metabolism, which indicates that there may be some interaction at the transcriptional level between genes involved in carbon and nitrogen metabolism