Showing papers by "Karl V. Wood published in 2010"
TL;DR: The data indicate that the recent amplification of a single-copy MgDNMT gene made it susceptible to RIP, resulting in complete loss of cytosine methylation in M. graminicola, which most likely occurred within the past 10,500 years since the divergence between M. Graminicola and S1.
Abstract: A de novo search for repetitive elements in the genome sequence of the wheat pathogen Mycosphaerella graminicola identified a family of repeats containing a DNA cytosine methyltransferase sequence (MgDNMT). All 23 MgDNMT sequences identified carried signatures of repeat induced point mutation (RIP). All copies were subtelomeric in location except for one on chromosome 6. Synteny with M. fijiensis implied that the nontelomeric copy on chromosome 6 served as a template for subsequent amplifications. Southern analysis revealed that the MgDNMT sequence also was amplified in 15 additional M. graminicola isolates from various geographical regions. However, this amplification event was specific to M. graminicola; a search for MgDNMT homologs identified only a single, unmutated copy in the genomes of 11 other ascomycetes. A genome-wide methylation assay revealed that M. graminicola lacks cytosine methylation, as expected if its MgDNMT gene is inactivated. Methylation was present in several other species tested, including the closest known relatives of M. graminicola, species S1 and S2. Therefore, the observed changes most likely occurred within the past 10,500 years since the divergence between M. graminicola and S1. Our data indicate that the recent amplification of a single-copy MgDNMT gene made it susceptible to RIP, resulting in complete loss of cytosine methylation in M. graminicola.
33 citations
TL;DR: The combination of (1)H NMR and PCA is a useful tool for the discrimination of maize silks in respect to their chemical composition, including rapid authentication of the raw material of current pharmacological interest.
Abstract: Aqueous extract from maize silks is used by traditional medicine for the treatment of several ailments, mainly related to the urinary system. This work focuses on the application of NMR spectroscopy and chemometric analysis for the determination of metabolic fingerprint and pattern recognition of silk extracts from seven maize landraces cultivated in southern Brazil. Principal component analysis (PCA) of the 1H NMR data set showed clear discrimination among the maize varieties by PC1 and PC2, pointing out three distinct metabolic profiles. Target compounds analysis showed significant differences (p < 0.05) in the contents of protocatechuic acid, gallic acid, t-cinnamic acid, and anthocyanins, corroborating the discrimination of the genotypes in this study as revealed by PCA analysis. Thus the combination of 1H NMR and PCA is a useful tool for the discrimination of maize silks in respect to their chemical composition, including rapid authentication of the raw material of current pharmacological interest.
29 citations
TL;DR: Addition of the nonsteroidal anti-inflammatory, COX-2 selective drug, NM, to SIS attenuates adhesion extent and tenacity when compared with surgical placement of SIS or PPM alone.
Abstract: Adhesion formation is a common complication in abdominal surgery with incidence as high as 93% and small bowel obstruction a common complication. Because the extracellular matrix material, small intestinal submucosa (SIS), is commonly used in various surgical procedures, methods to inhibit adhesiogenesis are of great interest. This study was undertaken to determine if incorporation of nimesulide (NM), a selective cyclooxygenase (COX)-2 inhibitor, could reduce the extent and tenacity of intraabdominal adhesion formation associated with SIS implantation. Female Sprague–Dawley rats underwent a cecal abrasion surgical procedure to induce adhesiogenesis. Rats were either left untreated or treated by direct application over the injured cecum with polypropylene mesh (PPM); SIS; SIS containing a low dose of NM; or SIS containing a high dose of NM. Rats were euthanized 21 days later, and adhesion extent and tenacity were evaluated using standard scales (0 = minimal adhesiogenesis; 4 = severe adhesiogenesis). Addition of NM to SIS resulted in a significant (p < 0.05) reduction in adhesion extent and in a similar reduction in adhesion tenacity for SIS containing a low dose of NM. Adhesions typically extended from the abraded cecal surface to the body wall and were characterized histologically by fibrous tissue adherent to the cecal wall. In conclusion, addition of the nonsteroidal anti-inflammatory, COX-2 selective drug, NM, to SIS attenuates adhesion extent and tenacity when compared with surgical placement of SIS or PPM alone. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
6 citations
TL;DR: Using lethality to brine shrimp, activity-directed fractionation of extracts of Asimina parviflora (Michx.) Dunal has led to the isolation of two new and four known acetogenins (1, 6) as mentioned in this paper.
Abstract: Using lethality to brine shrimp, activity-directed fractionation of extracts of Asimina parviflora (Michx.) Dunal. (Annonaceae) has led to the isolation of two new and four known acetogenins (1–6). Compound 1, parvifloracin, is the first nonadjacent bistetrahydrofuran acetogenin with 35 carbons. Compound 2, parviflorin, is an unusual adjacent bistetrahydrofuran acetogenin with 35 carbons. Bullatacin (3), molvizarin (4), annonacin (5), and goniothalamicin (6) are also reported for the first time from this plant. Brine shrimp lethality test data and comparative cytotoxicities of 1–6 against three human solid tumor cell lines are presented.