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941.
Inhibition of Plant-Pathogenic Bacteria by Short Synthetic Cecropin A-Melittin Hybrid Peptides 总被引:6,自引:2,他引:6 下载免费PDF全文
Rafael Ferre Esther Badosa Lidia Feliu Marta Planas Emili Montesinos Eduard Bardají 《Applied microbiology》2006,72(5):3302-3308
Short peptides of 11 residues were synthesized and tested against the economically important plant pathogenic bacteria Erwinia amylovora, Pseudomonas syringae, and Xanthomonas vesicatoria and compared to the previously described peptide Pep3 (WKLFKKILKVL-NH2). The antimicrobial activity of Pep3 and 22 analogues was evaluated in terms of the MIC and the 50% effective dose (ED50) for growth. Peptide cytotoxicity against human red blood cells and peptide stability toward protease degradation were also determined. Pep3 and several analogues inhibited growth of the three pathogens and had a bactericidal effect at low micromolar concentrations (ED50 of 1.3 to 7.3 μM). One of the analogues consisting of a replacement of both Trp and Val with Lys and Phe, respectively, resulted in a peptide with improved bactericidal activity and minimized cytotoxicity and susceptibility to protease degradation compared to Pep3. The best analogues can be considered as potential lead compounds for the development of new antimicrobial agents for use in plant protection either as components of pesticides or expressed in transgenic plants. 相似文献
942.
Mazoir N Benharref A Bailén M Reina M González-Coloma A Martínez-Díaz RA 《Zeitschrift für Naturforschung. C, Journal of biosciences》2011,66(7-8):360-366
The in vitro activity on Leishmania infantum promastigotes and Trypanosoma cruzi epimastigotes of 25 semisynthetic terpenoid derivatives has been evaluated. These compounds were obtained through chemical modifications of the major components of Euphorbia resinifera (alpha-euphol and alpha-euphorbol) and Euphorbia officinarum (obtusifoliol and 31-norlanosterol). Leishmaniasis and Chagas' disease are major worldwide health problems. The drugs of choice for their treatment are still problematic in both cases, and therefore there is an urgent need to discover new drugs with high activity and low side effects. Natural products have become a key source of new drugs in the last years. The genus Euphorbia has been the subject of abundant phytochemical and pharmacological research because of its potential medical applications, but the antiparasitic effects of derivatives from plants of this genus are still unknown. Our results showed that 76% and 64% of the test compounds had antiparasitic effects on L. infantum and T cruzi, respectively. The different activities on both parasites, especially their moderate effects on mammalian cells, indicate an interesting selective toxicity. 相似文献
943.
Lertxundi U Peral J Hernández R 《Revista espa?ola de geriatría y gerontología》2011,46(3):170-1; author reply 170
944.
Genotoxicity of diphenyl diselenide in bacteria and yeast 总被引:2,自引:0,他引:2
Rosa RM Sulzbacher K Picada JN Roesler R Saffi J Brendel M Henriques JA 《Mutation research》2004,563(2):107-115
Diphenyl diselenide (DPDS) is an electrophilic reagent used in the synthesis of a variety of pharmacologically active organic selenium compounds. This may increase the risk of human exposure to the chemical at the workplace. We have determined its mutagenic potential in the Salmonella/microsome assay and used the yeast Saccharomyces cerevisiae to assay for putative genotoxicity, recombinogenicity and to determine whether DNA damage produced by DPDS is repairable. Only in exponentially growing cultures was DPDS able to induce frameshift mutations in S. typhimurium and haploid yeast and to increase crossing over and gene conversion frequencies in diploid strains of S. cerevisiae. Thus, DPDS presents a behavior similar to that of an intercalating agent. Mutants defective in excision-resynthesis repair (rad3, rad1), in error-prone repair (rad6) and in recombinational repair (rad52) showed higher than WT-sensitivity to DPDS. It appears that this compound is capable of inducing single and/or double strand breaks in DNA. An epistatic interaction was shown between rad3-e5 and rad52-1 mutant alleles, indicating that excision-resynthesis and strand-break repair may possess common steps in the repair of DNA damage induced by DPDS. DPDS was able to enhance the mutagenesis induced by oxidative mutagens in bacteria. N-acetylcysteine, a glutathione biosynthesis precursor, prevented mutagenesis induced by DPDS in yeast. We have shown that DPDS is a weak mutagen which probably generates DNA strand breaks through both its intercalating action and pro-oxidant effect. 相似文献
945.
Background
Recent work has revealed that many biological systems keep functioning in the face of mutations and therefore can be considered genetically robust. However, several issues related to robustness remain poorly understood, such as its implications for evolvability (the ability to produce adaptive evolutionary innovations). 相似文献946.
Rosana S Lopes Marcelo M Cardoso Arthur O Sampaio Mario Santos BarbosaJr Celice C Souza Michelle C da Silva Elane Magno N Ferreira Marco Aurelio M Freire Rafael Rodrigues Lima Walace Gomes-Leal 《Journal of biosciences》2016,41(3):381-394
Neuroblasts from the subventricular zone (SVZ) migrate to striatum following stroke, but most of them die in the ischaemic milieu and this can be related to exacerbated microglial activation. Here, we explored the effects of the non-steroidal anti-inflammatory indomethacin on microglial activation, neuronal preservation and neuroblast migration following experimental striatal stroke in adult rats. Animals were submitted to endothelin-1 (ET-1)-induced focal striatal ischaemia and were treated with indomethacin or sterile saline (i.p.) for 7 days, being perfused after 8 or 14 days. Immunohistochemistry was performed to assess neuronal loss (anti-NeuN), microglial activation (anti-Iba1, ED1) and migrating neuroblasts (anti-DCX) by counting NeuN, ED1 and DCX-positive cells in the ischaemic striatum or SVZ. Indomethacin treatment reduced microglia activation and the number of ED1+ cells in both 8 and 14 days post injury as compared with controls. There was an increase in the number of DCX+ cells in both SVZ and striatum at the same survival times. Moreover, there was a decrease in the number of NeuN+ cells in indomethacin-treated animals as compared with the control group at 8 days but not after 14 days post injury. Our results suggest that indomethacin treatment modulates microglia activation, contributing to increased neuroblast proliferation in the SVZ and migration to the ischaemic striatum following stroke. 相似文献
947.
Carsten Schwarz Jean-Philippe Bouchara Walter Buzina Vanda Chrenkova Hanna Dmeńska Elia Gomez Garcia de la Pedrosa Rafael Cantón Ersilia Fiscarelli Yohann Le Govic Nahid Kondori Tadeja Matos Ewa Romanowska Stefan Ziesing Ludwig Sedlacek 《Mycopathologia》2018,183(1):7-19
The achievement of a better life for cystic fibrosis (CF) patients is mainly caused by a better management and infection control over the last three decades. Herein, we want to summarize the cornerstones for an effective management of CF patients and to give an overview of the knowledge about the fungal epidemiology in this clinical context in Europe. Data from a retrospective analysis encompassing 66,616 samples from 3235 CF patients followed-up in 9 CF centers from different European countries are shown. 相似文献
948.
Cássio S. Meira José Maurício dos Santos Filho Caroline C. Sousa Pâmela S. Anjos Jéssica V. Cerqueira Humberto A. Dias Neto Rafael G. da Silveira Helena M. Russo Jean-Luc Wolfender Emerson F. Queiroz Diogo R.M. Moreira Milena B.P. Soares 《Bioorganic & medicinal chemistry》2018,26(8):1971-1985
4-(Nitrophenyl)hydrazone derivatives of N-acylhydrazone were synthesized and screened for suppress lymphocyte proliferation and nitrite inhibition in macrophages. Compared to an unsubstituted N-acylhydrazone, active compounds were identified within initial series when hydroxyl, chloride and nitro substituents were employed. Structure-activity relationship was further developed by varying the position of these substituents as well as attaching structurally-related substituents. Changing substituent position revealed a more promising compound series of anti-inflammatory agents. In contrast, an N-methyl group appended to the 4-(nitrophenyl)hydrazone moiety reduced activity. Anti-inflammatory activity of compounds is achieved by modulating IL-1β secretion and prostaglandin E2 synthesis in macrophages and by inhibiting calcineurin phosphatase activity in lymphocytes. Compound SintMed65 was advanced into an acute model of peritonitis in mice, where it inhibited the neutrophil infiltration after being orally administered. In summary, we demonstrated in great details the structural requirements and the underlying mechanism for anti-inflammatory activity of a new family of hydrazone-N-acylhydrazone, which may represent a valuable medicinal chemistry direction for the anti-inflammatory drug development in general. 相似文献
949.
950.
Christine Acevedo-Schermerhorn Julie Gray-Bablin Rafael Gama Paulette J. McCormick 《Experimental cell research》1997,236(2):510
Previously we described an embryonic cell surface glycoprotein, ESGp, associated with the t-embryonic lethal alleles of the mouse t complex. This antigen is expressed on the cell surface of both early mouse embryos and embryonal carcinoma (EC) cell lines. The antigen is localized to areas of cell–cell contact in EC lines and redistributes to the outer edges of the blastomeres during compaction, thereby indicating a potential role in embryonic cell–cell interaction. We now report that this t-complex-associated ESGp is homologous to the mouse lysosomal-associated membrane protein-1 (LAMP-1). Limited protein sequence analyses of the amino terminal and an internal peptide indicate considerable homology with the LAMP-1 protein. Biochemical parameters such as protein core size, sulfation and phosphorylation status, and resistance to proteolysis also demonstrate homology. While we detect only a single message with a mouse LAMP-1 cDNA probe via Northern blotting, Southern analyses indicate the existence of at least two homologous LAMP-1 genes. Additionally, we present evidence suggesting that ESGp/LAMP-1 serves as a substrate which may be differentially glycosylated by the activities of the gene products of the different t-lethal alleles. 相似文献