32 research outputs found
Ectopic expression of dehydration responsive element binding proteins (StDREB2) confers higher tolerance to salt stress in potato
Dehydration responsive element binding proteins (DREB) are members of a larger family of transcription factors, many of which have been reported to contribute to plant responses to abiotic stresses in several species. While, little is known about their role in potato (Solanum tuberosum). This report describes the cloning and characterization of a DREB transcription factor cDNA, StDREB2, isolated from potato(cv Nicola) plants submitted to salt treatment. Based on a multiple sequence alignment, this protein was classified into the A-5 group of DREB subfamily. Expression studies revealed that StDREB2 was induced in leaves, roots and stems upon various abiotic stresses and in response to exogenous treatment with abscisic acid (ABA). In agreement with this expression pattern, over-expression of StDREB2 in transgenic potato plants resulted in enhanced tolerance to salt stress. These data suggest that the isolated StDREB2 encodes a functional protein involved in plant response to different abiotic stresses. An electrophoretic mobility shift assay (EMSA) indicated that the StDREB2 protein bound specifically to the DRE core element (ACCGAGA) in vitro. Moreover, Semi quantitative RT-PCR analysis revealed that the transcript level of a putative target gene i.e. d1-pyrroline-5-carboxylate synthase (P5CS) was upregulated in transgenic plants submitted to salt stress conditions. A concomitant increase in proline accumulation was also observed under these conditions. Taking together, all these data suggest that StDREB2 takes part in the processes underlying plant responses to abiotic stresses probably via the regulation of ABA hormone signaling and through a mechanism allowing proline synthesis
Évoquer et traiter en temps et en heure le paludisme
International audienceMalaria is a medical emergency that kills about 20 people annually in France. Adult and pediatric emergency departments are on the front line for its diagnosis and for evaluating the severity of the cases, which depends on the choice of the initial treatment and the final decision of orientation (ambulatory treatment, admission, admission in intensive care). Integrating the patient upon discharge from the emergency department into a care pathway adapted to their clinical condition and personal and social context is essential to the quality of care and patient safety. But the proper organization of the clinical patient pathway within the emergency department is also crucial. We present here a reminder of the main diagnostic and therapeutic difficulties and the diagnostic and therapeutic decision support tools to be implemented in the emergency department to improve the quality and safety of patient care
Overexpression of StDREB1 Transcription Factor Increases Tolerance to Salt in Transgenic Potato Plants
International audienceIt has been established that drought-responsiveelement binding (DREB) proteins correspond to transcriptionfactors which play important regulatory roles in plant response to abiotic and biotic stresses. In this study, a novel cDNA encoding DREB transcription factor, designatedStDREB1, was isolated from potato (Solanum tuberosum L.). This protein was classified in the A-4 group of DREB subfamily based on multiple sequence alignments and phylogenetic characterization. Semi-quantitativeRT-PCR showed that StDREB1 is expressed in leaves,stems, and roots under stress conditions and it is greatlyinduced by NaCl, drought, low temperature, and abscisicacid (ABA) treatments. Overexpression of StDREB1 cDNAin transgenic potato plants exhibited an improved salt anddrought stress tolerance in comparison to the non-transformed controls. The enhanced stress tolerance may beassociated with the increase in P5CS-RNA expression (d1-pyrroline-5-carboxylate synthetase) and the subsequentaccumulation of proline osmoprotectant in addition to abetter control of water loss. Overexpression of StDREB1also activated stress-responsive genes, such as thoseencoding calcium-dependent protein kinases (CDPKs), intransgenic potatoes under standard and high salt conditions.These data suggest that the StDREB1 transcription factor isinvolved in the regulation of salt stress tolerance in potato by the activation of different downstream gene expression
Identification and functional characterization of ten AP2/ERF genes in potato
International audienceEthylene-responsive element-binding factors (ERF) constitute one of the largest transcription factor families in plants. In this study, we describe the cloning and the characterization of ten cDNAs encoding ERF factors from potato. The alignment of their AP2/ERF (Apetala2/ethylene-responsive factor) domain led to the identification of six StERFs (Solanum tuberosum ERFs) and four StDREBs (dehydration responsive element binding). The phylogeny and the sequence characterization allowed the classification of these StERFs into five ERF families. Expression analysis by semi-quantitative RT-PCR of these genes revealed that most of them are induced by hormone treatment such as abscisic acid, ethephon, jasmonic acid and salicylic acid. However, salt stress induced the expression of all StDREB but only three StERF genes. These results suggest that these transcription factors are involved in salt stress response. The StDREB1 and StDREB2 genes showed strong increase in expression in response to drought stress. In an attempt to improve drought tolerance in potato, we overexpressed StDREB1 and StDREB2 in transgenic potato plants (S. tuberosum L. Group Tuberosum) cv. Belle de Fontenay (BF15) and Spunta, respectively. The level of drought tolerance of these transgenic lines was significantly greater than that of wild-type control plants as measured by relative water content H2O2 content, free proline and total soluble sugars. The results suggest that the StDREB1 and StDREB2 as AP2/ERF transcription factors may play dual roles in response to drought stress in potato
Review on the Correlation of Quantitative PCR Cycle Threshold Values of Gastrointestinal Pathogens with Patient Clinical Presentation and Outcomes
Background: Quantitative (q) polymerase chain reaction (PCR) cycle threshold (Ct) values represent the number of amplification cycles required for a positive PCR result and are a proxy of pathogen quantity in the tested sample. The clinical utility of Ct values remains unclear for gastrointestinal infections. Objectives: This systematic review assesses the global medical literature for associations between Ct values of gastrointestinal pathogens and patient presentation and clinical outcomes. Data Sources: MEDLINE, EMBASE, Cochrane library databases: searched January 14-17, 2020. Study Eligibility Criteria: Studies reporting on the presence or absence of an association between Ct values and clinical outcomes in adult and pediatric populations were included. Animal studies, reviews, meta-analyses, and non-English language studies were excluded. Participants: Humans infected with gastrointestinal pathogens, detected with qPCR. Interventions: Diagnostics assessing Ct values. Extracted data were reported narratively. Results: Thirty-three eligible studies were identified; the most commonly studied pathogens were Clostridioides difficile (n = 15), norovirus (n = 10), and rotavirus (n = 9). Statistically significant associations between low C. difficile Ct values and increased symptom severity or poor outcome were reported in 4/8 (50%) studies, and increased risk of death in 1/2 (50%) studies; no significant associations were found between Ct value and duration of symptoms or length of hospital stay. Among studies of norovirus, 5/7 (71%), mainly genogroup II, reported symptomatic cases with significantly lower median Ct values than controls. Significantly lower rotavirus Ct values were also observed in symptomatic cases vs. controls in 3/7 (43%) studies, and associated with more severe symptoms in 2/2 studies. Contradictory associations were identified for non-C. difficile bacterial and parasitic pathogens. Conclusions: In conclusion, some studies reported clinically useful associations between Ct values and patient or healthcare outcomes; additional, well-designed, large-scale trials are warranted based on these findings. Systematic Review Registration: [PROSPERO], identifier [CRD42020167239]
Factors associated with single-room assignment among patients admitted through the emergency department during influenza epidemics
International audienceIntroduction: Every winter, emergency departments (EDs) face overcrowding with patients presenting influenza-like symptoms, and organisational issues such as single room assignment and droplet precautions to avoid hospital-acquired influenza. Our main objective was to assess the impact of PCR results and patient's severity on single room assignment. Methods: All patients admitted to Bichat-Claude Bernard Hospital through the ED and tested for influenza by PCR (GenXpert, Cepheid) or (FilmArray, BioMérieux) on a nasopharyngeal swab were retrospectively included during three influenza seasons (2015-2018. Results: Of 1,330 included patients, 278 (20.9%) had a positive PCR for influenza. The median time to obtain a PCR result was 19 hours, and 238 (18.3%) patients were assigned a single room. Among patients with positive and negative influenza PCR, 22.3% and 16.7% were assigned a single room (p = 0.03). The multivariable analysis was performed on the two first epidemic periods, excluding the third epidemic because of the concomitant use of influenza immune-chromatic test. Only level 1 of the Emergency severity index (ESI) (aOR, 1.9; 95% CI, 1.3-2.8; p < 0.01) was associated with single-room assignment. PCR result was not statistically associated with the decision of single room assignment (aOR, 1.4; 95%CI, 1.0-1.4; p = 0.07). Conclusion: A PCR positive for influenza was not significantly associated with single-room assignment. Less than one quarter of influenza patients were adequately assigned a single room, likely due to the long turnaround time of PCR result and other conflicting indications for single room-assignment. Accelerating biological diagnosis could improve single-room assignment
Main characteristics of the study population.
<p>Main characteristics of the study population.</p