ALBERT

Description: Enteropathogenic Escherichia coli (EPEC) is distinguished mainly by the presence of EPEC adherence factor plasmid (pEAF) in typical EPEC (tEPEC) and its absence in atypical EPEC (aEPEC). The initial adherence to ...

Description: Background: T-cell intracellular antigen (TIA) proteins function as regulators of cell homeostasis. These proteins control gene expression globally at multiple levels in response to dynamic regulatory changes and environmental stresses. Herein we identified a micro(mi)RNA signature associated to transiently TIA-depleted HeLa cells and analyzed the potential role of miRNAs combining genome-wide analysis data on mRNA and miRNA profiles. Results: Using high-throughput miRNA expression profiling, transient depletion of TIA-proteins in HeLa cells was observed to promote significant and reproducible changes affecting to a pool of up-regulated miRNAs involving miR-30b-3p, miR125a-3p, miR-193a-5p, miR-197-3p, miR-203a, miR-210, miR-371-5p, miR-373-5p, miR-483-5p, miR-492, miR-498, miR-503-5p, miR-572, miR-586, miR-612, miR-615-3p, miR-623, miR-625-5p, miR-629-5p, miR-638, miR-658, miR-663a, miR-671-5p, miR-769-3p and miR-744-5p. Some up-regulated and unchanged miRNAs were validated and previous results confirmed by reverse transcription and real time PCR. By target prediction of the miRNAs and combined analysis of the genome-wide expression profiles identified in TIA-depleted HeLa cells, we detected connections between up-regulated miRNAs and potential target genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database analysis suggest that target genes are related with biological processes associated to the regulation of DNA-dependent transcription, signal transduction and multicellular organismal development as well as with the enrichment of pathways involved in cancer, focal adhesion, regulation of actin cytoskeleton, endocytosis and MAPK and Wnt signaling pathways, respectively. When the collection of experimentally defined differentially expressed genes in TIA-depleted HeLa cells was intersected with potential target genes only 7 out of 68 (10%) up- and 71 out of 328 (22%) down-regulated genes were shared. GO and KEGG database analyses showed that the enrichment categories of biological processes and cellular pathways were related with innate immune response, signal transduction, response to interleukin-1, glomerular basement membrane development as well as neuroactive ligand-receptor interaction, endocytosis, lysosomes and apoptosis, respectively. Conclusion: All this considered, these observations suggest that individual miRNAs could act as potential mediators of the epigenetic switch linking transcriptomic dynamics and cell phenotypes mediated by TIA proteins.

Description: Background: Clostridium thermocellum is an anaerobic thermophilic bacterium that exhibits high levels of cellulose solublization and produces ethanol as an endproduct of its metabolism. Using cellulosic biomass as a feedstock for fuel production is an attractive prospect, however, growth arrest can negatively impact ethanol production by fermentative microorganisms such as C. thermocellum. Understanding conditions that lead to non-growth states in C. thermocellum can positively influence process design and culturing conditions in order to optimize ethanol production in an industrial setting. Results: We report here that Clostridium thermocellum ATCC 27405 enters non-growth states in response to specific growth conditions. Non-growth states include the formation of spores and a L-form-like state in which the cells cease to grow or produce the normal end products of metabolism. Unlike other sporulating organisms, we did not observe sporulation of C. thermocellum when subjected to low carbon or nitrogen environments. However, sporulation did occur in response to transfers between soluble and insoluble substrates, resulting in approximately 7% mature spores. Exposure to oxygen caused a similar sporulation response. Starvation conditions during continuous culture did not result in spore formation, but caused the majority of cells to transition to a L-form state. Both spores and L-forms were determined to be viable. Spores exhibited enhanced survival in response to high temperature and prolonged storage compared to L-forms and vegetative cells. However, L-forms exhibited faster recovery compared to both spores and stationary phase cells when cultured in rich media. Conclusions: Both spores and L-forms cease to produce ethanol, but provide other advantages for C. thermocellum including enhanced survival for spores and faster recovery for L-forms. Understanding the conditions that give rise to these two different non-growth states, and the implications that each has for enabling or enhancing C. thermocellum survival may promote the efficient cultivation of this organism and aid in its development as an industrial microorganism.

Description: Background: Cecropin A is a natural antimicrobial peptide that exhibits rapid, potent and long-lasting lytic activity against a broad spectrum of pathogens, thus having great biotechnological potential. Here, we report a system for producing bioactive cecropin A in rice seeds. Results: Transgenic rice plants expressing a codon-optimized synthetic cecropin A gene drived by an endosperm-specific promoter, either the glutelin B1 or glutelin B4 promoter, were generated. The signal peptide sequence from either the glutelin B1 or the glutelin B4 were N-terminally fused to the coding sequence of the cecropin A. We also studied whether the presence of the KDEL endoplasmic reticulum retention signal at the C-terminal has an effect on cecropin A subcellular localization and accumulation. The transgenic rice plants showed stable transgene integration and inheritance. We show that cecropin A accumulates in protein storage bodies in the rice endosperm, particularly in type II protein bodies, supporting that the glutelin N-terminal signal peptides play a crucial role in directing the cecropin A to this organelle, independently of being tagged with the KDEL endoplasmic reticulum retention signal. The production of cecropin A in transgenic rice seeds did not affect seed viability or seedling growth. Furthermore, transgenic cecropin A seeds exhibited resistance to infection by fungal and bacterial pathogens (Fusarium verticillioides and Dickeya dadantii, respectively) indicating that the in planta-produced cecropin A is biologically active. Conclusions: Rice seeds can sustain bioactive cecropin A production and accumulation in protein bodies. The system might benefit the production of this antimicrobial agent for subsequent applications in crop protection and food preservation.

Description: The simultaneous presence of a heterozygous β-thalassemia with α-gene triplication may cause anything from a thalassemia trait to thalassemia intermedia of mild to moderate severity.

Description: Background: In this research, an extension to our previous work published in the Clinical Journal of Sports Medicine in 2009, we studied subjects that differed in terms of age and training status and assessed the impact of prolonged exercise on systolic and left ventricular diastolic function and cardiac biomarkers levels, recognized as identifiers of cardiac damage and dysfunction. We also assessed the possible influence of event duration, exercise intensity and weight loss (dehydration) on left ventricular diastolic function.FindingsNinety-one male cyclists were assessed by echocardiography and serum biomarkers before and after the 2005 Quebrantahuesos cycling event (206 km long and with an accumulated slope of 3800 m). Cardiac function was assessed by echocardiography and cardiac biomarkers were assessed in blood serum. Echocardiograms measured left ventricular internal dimension during diastole and systole, left ventricular posterior wall thickness during diastole, interventricular septum thickness during diastole, left ventricular ejection fraction and diastolic filling. The heart rate of 50 cyclists was also monitored during the race to evaluate exercise intensity. Echocardiograph results indicated that left ventricular diastolic and systolic function decreased after the race, with systolic function reduced to a significant degree. Left ventricular ejection fraction was below 55% in 29 cyclists. The decrease in left ventricular systolic and diastolic function did not correlate with age, training status, race duration, weight loss or exercise intensity. Conclusions: Left ventricular systolic and diastolic function was reduced and cardiac biomarkers were increased after the cycling event, but the mechanisms behind such outcomes remain unclear.

Description: Background: In this research, an extension to our previous work published in the Clinical Journal of Sports Medicine in 2009, we studied subjects that differed in terms of age and training status and assessed the impact of prolonged exercise on systolic and left ventricular diastolic function and cardiac biomarkers levels, recognized as identifiers of cardiac damage and dysfunction. We also assessed the possible influence of event duration, exercise intensity and weight loss (dehydration) on left ventricular diastolic function.FindingsNinety-one male cyclists were assessed by echocardiography and serum biomarkers before and after the 2005 Quebrantahuesos cycling event (206 km long and with an accumulated slope of 3800 m). Cardiac function was assessed by echocardiography and cardiac biomarkers were assessed in blood serum. Echocardiograms measured left ventricular internal dimension during diastole and systole, left ventricular posterior wall thickness during diastole, interventricular septum thickness during diastole, left ventricular ejection fraction and diastolic filling. The heart rate of 50 cyclists was also monitored during the race to evaluate exercise intensity. Echocardiograph results indicated that left ventricular diastolic and systolic function decreased after the race, with systolic function reduced to a significant degree. Left ventricular ejection fraction was below 55% in 29 cyclists. The decrease in left ventricular systolic and diastolic function did not correlate with age, training status, race duration, weight loss or exercise intensity. Conclusions: Left ventricular systolic and diastolic function was reduced and cardiac biomarkers were increased after the cycling event, but the mechanisms behind such outcomes remain unclear.

Description: Background: Percutaneous coronary intervention with placement of a drug-eluting stent in a diabetic patient with ST-elevation myocardial infarction is a relatively common procedure, and always requires subsequent treatment with dual antiplatelet therapy. It is sometimes necessary to add oral anticoagulation therapy because of individual clinical circumstances, which further increases the risk of bleeding.Case presentationA 66-year-old hypertensive diabetic man with a history of gastrointestinal bleeding was admitted with an ST-elevation inferior myocardial infarction that had been evolving over 72 h. Electrocardiography showed ST segment elevation in the inferior leads and Q waves in the inferior and anterior leads. He reported a similar episode of chest pain 1 month previously, for which he had not sought medical treatment. Coronary angiography showed chronic occlusion of the mid-left anterior descending coronary artery, and acute occlusion of the mid-right coronary artery. He was treated by percutaneous coronary intervention, with placement of a drug-eluting stent in the right coronary artery. Soon after admission, transthoracic echocardiography showed abnormal left ventricular contractility and a large left intraventricular thrombus. Three weeks after admission, the patient was discharged on dual antiplatelet therapy (clopidogrel and aspirin) and oral anticoagulation therapy (acenocoumarol). Four months after discharge, transthoracic echocardiography showed absence of left ventricular thrombus and resolution of the abnormal contractility in the area supplied by the revascularized right coronary artery. Given the high risk of bleeding, oral anticoagulation therapy was stopped. Six months later, transthoracic echocardiography showed recurrent left ventricular apical thrombus, and an underlying hypercoagulable state was ruled out. Oral anticoagulation therapy was restarted on an indefinite basis, and dual antiplatelet therapy was continued. Conclusion: The present case illustrates the need for repeat transthoracic echocardiography following the withdrawal of oral anticoagulation therapy in patients with ST-elevation myocardial infarction, both to monitor thrombus status and to assess left ventricular segmental contraction. In patients who require anticoagulation, avoidance of a drug-eluting stent is strongly preferred and second-generation stents are recommended. The alternative regimen of oral anticoagulation and clopidogrel may be considered in this scenario. In patients with recurrent intraventricular thrombus an underlying hypercoagulable state should be ruled out.

Description: Background: Percutaneous coronary intervention with placement of a drug-eluting stent in a diabetic patient with ST-elevation myocardial infarction is a relatively common procedure, and always requires subsequent treatment with dual antiplatelet therapy. It is sometimes necessary to add oral anticoagulation therapy because of individual clinical circumstances, which further increases the risk of bleeding.Case presentationA 66-year-old hypertensive diabetic man with a history of gastrointestinal bleeding was admitted with an ST-elevation inferior myocardial infarction that had been evolving over 72 h. Electrocardiography showed ST segment elevation in the inferior leads and Q waves in the inferior and anterior leads. He reported a similar episode of chest pain 1 month previously, for which he had not sought medical treatment. Coronary angiography showed chronic occlusion of the mid-left anterior descending coronary artery, and acute occlusion of the mid-right coronary artery. He was treated by percutaneous coronary intervention, with placement of a drug-eluting stent in the right coronary artery. Soon after admission, transthoracic echocardiography showed abnormal left ventricular contractility and a large left intraventricular thrombus. Three weeks after admission, the patient was discharged on dual antiplatelet therapy (clopidogrel and aspirin) and oral anticoagulation therapy (acenocoumarol). Four months after discharge, transthoracic echocardiography showed absence of left ventricular thrombus and resolution of the abnormal contractility in the area supplied by the revascularized right coronary artery. Given the high risk of bleeding, oral anticoagulation therapy was stopped. Six months later, transthoracic echocardiography showed recurrent left ventricular apical thrombus, and an underlying hypercoagulable state was ruled out. Oral anticoagulation therapy was restarted on an indefinite basis, and dual antiplatelet therapy was continued. Conclusions: The present case illustrates the need for repeat transthoracic echocardiography following the withdrawal of oral anticoagulation therapy in patients with ST-elevation myocardial infarction, both to monitor thrombus status and to assess left ventricular segmental contraction. In patients who require anticoagulation, avoidance of a drug-eluting stent is strongly preferred and second-generation stents are recommended. The alternative regimen of oral anticoagulation and clopidogrel may be considered in this scenario. In patients with recurrent intraventricular thrombus an underlying hypercoagulable state should be ruled out.

Description: Background: Faba bean (Vicia faba L.) is among the earliest domesticated crops from the Near East. Today this legume is a key protein feed and food worldwide and continues to serve an important role in culinary traditions throughout Middle East, Mediterranean region, China and Ethiopia. Adapted to a wide range of soil types, the main faba bean breeding objectives are to improve yield, resistance to biotic and abiotic stresses, seed quality and other agronomic traits. Genomic approaches aimed at enhancing faba bean breeding programs require high-quality genetic linkage maps to facilitate quantitative trait locus analysis and gene tagging for use in a marker-assisted selection. The objective of this study was to construct a reference consensus map in faba bean by joining the information from the most relevant maps reported so far in this crop. Results: A combination of two approaches, increasing the number of anchor loci in diverse mapping populations and joining the corresponding genetic maps, was used to develop a reference consensus map in faba bean. The map was constructed from three main recombinant inbreed populations derived from four parental lines, incorporates 729 markers and is based on 69 common loci. It spans 4,602 cM with a range from 323 to 1041 loci in six main linkage groups or chromosomes, and an average marker density of one locus every 6 cM. Locus order is generally well maintained between the consensus map and the individual maps. Conclusion: We have constructed a reliable and fairly dense consensus genetic linkage map that will serve as a basis for genomic approaches in faba bean research and breeding. The core map contains a larger number of markers than any previous individual map, covers existing gaps and achieves a wider coverage of the large faba bean genome as a whole. This tool can be used as a reference resource for studies in different genetic backgrounds, and provides a framework for transferring genetic information when using different marker technologies. Combined with syntenic approaches, the consensus map will increase marker density in selected genomic regions and will be useful for future faba bean molecular breeding applications.