Chloride regulates leaf cell size and water relations in tobacco plants

19 páginas.-- 9 figuras.-- 5 tablas.-- 77 referencias.-- Supplementary Data: Supplementary_figures_S1_S7___Tables_S1_S7.pdfChloride (Cl–) is a micronutrient that accumulates to macronutrient levels since it is normally available in nature and actively taken up by higher plants. Besides a role as an unspecific cell osmoticum, no clear biological roles have been explicitly associated with Cl– when accumulated to macronutrient concentrations. To address this question, the glycophyte tobacco (Nicotiana tabacum L. var. Habana) has been treated with a basal nutrient solution supplemented with one of three salt combinations containing the same cationic balance: Cl–-based (CL), nitrate-based (N), and sulphate+phosphate-based (SP) treatments. Under non-saline conditions (up to 5mM Cl–) and no water limitation, Cl– specifically stimulated higher leaf cell size and led to a moderate increase of plant fresh and dry biomass mainly due to higher shoot expansion. When applied in the 1–5mM range, Cl– played specific roles in regulating leaf osmotic potential and turgor, allowing plants to improve leaf water balance parameters. In addition, Cl– also altered water relations at the whole-plant level through reduction of plant transpiration. This was a consequence of a lower stomatal conductance, which resulted in lower water loss and greater photosynthetic and integrated water-use efficiency. In contrast to Cl–, these effects were not observed for essential anionic macronutrients such as nitrate, sulphate, and phosphate. We propose that the abundant uptake and accumulation of Cl– responds to adaptive functions improving water homeostasis in higher plants.This work was supported by the Spanish Ministry of Science and Innovation-FEDER grant AGL2009-08339/AGR. The help, expertise, and technical assistance of C. Rivero, A. Vázquez, S. Luque, B.J. Sañudo, F.J. Durán, Y. Pinto, and J. Espartero are gratefully acknowledged. We would like to extend our gratitude to the valuable reviews and contributions by the anonymous referees and the editor, Timothy Colmer, which helped us to improve the manuscript substantially.Peer reviewe

Disorder-specific functional abnormalities during sustained attention in youth with Attention Deficit Hyperactivity Disorder (ADHD) and with Autism

Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are often comorbid and share behavioural-cognitive abnormalities in sustained attention. A key question is whether this shared cognitive phenotype is based on common or different underlying pathophysiologies. To elucidate this question, we compared 20 boys with ADHD to 20 age and IQ matched ASD and 20 healthy boys using functional magnetic resonance imaging (fMRI) during a parametrically modulated vigilance task with a progressively increasing load of sustained attention. ADHD and ASD boys had significantly reduced activation relative to controls in bilateral striato–thalamic regions, left dorsolateral prefrontal cortex (DLPFC) and superior parietal cortex. Both groups also displayed significantly increased precuneus activation relative to controls. Precuneus was negatively correlated with the DLPFC activation, and progressively more deactivated with increasing attention load in controls, but not patients, suggesting problems with deactivation of a task-related default mode network in both disorders. However, left DLPFC underactivation was significantly more pronounced in ADHD relative to ASD boys, which furthermore was associated with sustained performance measures that were only impaired in ADHD patients. ASD boys, on the other hand, had disorder-specific enhanced cerebellar activation relative to both ADHD and control boys, presumably reflecting compensation. The findings show that ADHD and ASD boys have both shared and disorder-specific abnormalities in brain function during sustained attention. Shared deficits were in fronto–striato–parietal activation and default mode suppression. Differences were a more severe DLPFC dysfunction in ADHD and a disorder-specific fronto–striato–cerebellar dysregulation in ASD

A diphenyldiselenide derivative induces autophagy via JNK in HTB-54 lung cancer cells

Symmetric aromatic diselenides are potential anticancer agents with strong cytotoxic activity. In this study, the in vitro anticancer activities of a novel series of diarylseleno derivatives from the diphenyldiselenide (DPDS) scaffold were evaluated. Most of the compounds exhibited high efficacy for inducing cytotoxicity against different human cancer cell lines. DPDS 2, the compound with the lowest mean GI50 value, induced both caspase-dependent apoptosis and arrest at the G0/G1 phase in acute lymphoblastic leucemia CCRF-CEM cells. Consistent with this, PARP cleavage; enhanced caspase-2, -3, -8 and -9 activity; reduced CDK4 expression and increased levels of p53 were detected in these cells upon DPDS 2 treatment. Mutated p53 expressed in CCRF-CEM cells retains its transactivating activity. Therefore, increased levels of p21CIP1 and BAX proteins were also detected. On the other hand, DPDS 6, the compound with the highest selectivity index for cancer cells, resulted in G2/M cell cycle arrest and caspase-independent cell death in p53 deficient HTB-54 lung cancer cells. Autophagy inhibitors 3-methyladenine, wortmannin and chloroquine inhibited DPDS 6-induced cell death. Consistent with autophagy, increased LC3-II and decreased SQSTM1/p62 levels were detected in HTB-54 cells in response to DPDS 6. Induction of JNK phosphorylation and a reduction in phospho-p38 MAPK were also detected. Moreover, the JNK inhibitor SP600125-protected HTB-54 cells from DPDS 6-induced cell death indicating that JNK activation is involved in DPDS 6-induced autophagy. These results highlight the anticancer effects of these derivatives and warrant future studies examining their clinical potential

Chloride Nutrition Regulates development, Water Balance and Drought Resistance in Plants

6 páginas.-- 5 figuras.-- 9 referencias.-- Poster presentado en el XII Luso-Spanish Symposium on Plant Water Relations – Water to Feed the World. 30th of September – 3rd of October (Evora) PortugalCl- is a strange micronutrient since actual Cl- concentration in plants is about two orders of magnitude higher than the content required as essential micronutrient. This accumulation requires a high cost of energy, and since Cl- is a major osmotically active solute in the vacuole, we propose that Cl- plays a role in the regulation of water balance in plants. We show here that, when accumulated to macronutrient levels, Cl- specifically regulates leaf cell elongation and water balance parameters, improving water relations at both the leaf tissue and the whole plant levels, increasing drought resistance in higher plants.This work was supported by the Spanish Ministry of Science and Innovation-FEDER grant AGL2009-08339/AGR.Peer Reviewe

Occupational exposure to nano-TiO2 in the life cycle steps of new depollutant mortars used in construction

The present work is focused on the measurement of workers exposure to nano-TiO2 in the life cycle steps of depollutant mortars. It has been done in the framework of the SCAFFOLD project, which aims at the management of potential risks arising from the use of manufactured nanomaterials in construction. Main findings can be summarized as follows: (1) The occupational exposure to nano- TiO2 is below 0.3 mg/m3 for all measured scenarios. The highest concentrations were measured during the cleaning task (in the nano- TiO2 manufacturing process) and during the application (spraying) of depollutant coatings on a wall. (2) It was found a high release of particles above the background in several tasks as expected due to the nature of the activities performed. The maximum concentration was measured during drilling and during adding powder materials (mean total particle concentration up to 5.591E+04 particles/cm3 and 5.69E+04 particles/cm3). However, considering data on total particle concentration released, no striking differences have been observed when tasks have been performed using conventional materials in the sector (control) and when using materials doped with nano-objects.European Commission's FP

Identification of a novel quinoxaline-isoselenourea targeting the STAT3 pathway as a potential melanoma therapeutic

The prognosis for patients with metastatic melanoma remains very poor. Constitutive signal transducer and activator of transcription 3 (STAT3) activation has been correlated to metastasis, poor patient survival, larger tumor size, and acquired resistance against vemurafenib (PLX-4032), suggesting its potential as a molecular target. We recently designed a series of isoseleno- and isothio-urea derivatives of several biologically active heterocyclic scaffolds. The cytotoxic effects of lead isoseleno- and isothio-urea derivatives (compounds 1 and 3) were studied in a panel of five melanoma cell lines, including B-RAFV600E-mutant and wild-type (WT) cells. Compound 1 (IC50 range 0.8–3.8 µM) showed lower IC50 values than compound 3 (IC50 range 8.1–38.7 µM) and the mutant B-RAF specific inhibitor PLX-4032 (IC50 ranging from 0.4 to >50 µM), especially at a short treatment time (24 h). These effects were long-lasting, since melanoma cells did not recover their proliferative potential after 14 days of treatment. In addition, we confirmed that compound 1 induced cell death by apoptosis using Live-and-Dead, Annexin V, and Caspase3/7 apoptosis assays. Furthermore, compound 1 reduced the protein levels of STAT3 and its phosphorylation, as well as decreased the expression of STAT3-regulated genes involved in metastasis and survival, such as survivin and c-myc. Compound 1 also upregulated the cell cycle inhibitor p21. Docking studies further revealed the favorable binding of compound 1 with the SH2 domain of STAT3, suggesting it acts through STAT3 inhibition. Taken together, our results suggest that compound 1 induces apoptosis by means of the inhibition of the STAT3 pathway, non-specifically targeting both B-RAF-mutant and WT melanoma cells, with much higher cytotoxicity than the current therapeutic drug PLX-4032

Quality of life in metastatic pancreatic cancer patients receiving liposomal irinotecan plus 5-fluorouracil and leucovorin

Abstract Background The NAPOLI-1 study (NCT01494506) reported that liposomal irinotecan plus 5-fluorouracil and leucovorin (nal-IRI+5-FU/LV) improved overall survival vs 5-FU/LV with manageable toxicity in patients with metastatic pancreatic adenocarcinoma previously treated with gemcitabine-based therapy. Yet, clinicians need treatment strategies that also maintain the patient's health-related quality of life (HRQOL). Here, we report the HRQOL data. Methods Patients completed the European Organisation for Research and Treatment of Cancer QOL core questionnaire C30 (EORTC QLQ-C30) at baseline, every 6 weeks, and at 30 days after discontinuation of study treatment. Patient-reported outcomes (PROs) were scored according to EORTC guidelines. nal-IRI+5-FU/LV HRQOL was compared with 5-FU/LV. The PRO population comprised intent-to-treat patients who completed baseline and at least one subsequent assessment on the EORTC QLQ-C30. Data were also analysed for missingness. Results Of 236 patients in the intent-to-treat population, 128 (54.2%) comprised the PRO population (71 in the nal-IRI+5-FU/LV arm; 57 the in 5-FU/LV arm). Of the remaining 108 patients (45.8%) not included in the PRO population, most progressed rapidly, making participation difficult. Median change from baseline was ≤10 points at weeks 6 and 12 in global health status or functional and symptom scale scores, except for fatigue, which deteriorated by 11.1 points with nal-IRI+5-FU/LV but did not change vs 5-FU/LV. The proportion of patients whose HRQOL improved or deteriorated was not significantly different between the arms. Conclusion In the NAPOLI-1 study, HRQOL was maintained with nal-IRI+5-FU/LV in patients with metastatic pancreatic adenocarcinoma previously treated with a gemcitabine-based regimen, while survival was significantly extended

Quality of life: international and domestic students studying medicine in New Zealand

International students form a significant proportion of students studying within universities in Western countries. The quality of life perceptions of international medical students in comparison with domestic medical students has not been well documented. There is some evidence to suggest that international medical students may have different educational and social experiences in relation to their domestic peers. This study investigates the levels of quality of life experienced by international and domestic students studying medicine. A total of 548 medical students completed the abbreviated version of the World Health Organization Quality of Life questionnaire. The focus of the analysis was to evaluate differences between international and domestic students in their early clinical years. The responses were analysed using multivariate analysis of variance methods. International medical students are experiencing lower social and environmental quality of life compared with domestic peers. International medical students in New Zealand have expressed quality of life concerns, which likely have an impact on their academic achievement, feelings of wellness, acculturation, and social adaptation. The findings reinforce the need for creating stronger social networks and accessible accommodation, as well as developing systems to ensure safety, peer mentorship and student support.published_or_final_versio