221 research outputs found

    Overexpression of a Glutathione S-Transferase gene from P. vulgaris L. Improves salt stress Tolerance in Transgenic Tobacco Plants

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    Glutathione S-transferases (GSTs) are multifunctional proteins and forms major part, of plant cellular detoxification system and antioxidant enzyme network. Previously, a novel GST gene PvGSTU3-3 has been isolated from roots of Phaseolus vulgaris L. plants. The isoenzyme shows high antioxidant catalytic function and acts as hydroperoxidase, thioltransferase, and dehydroascorbate reductase. In the present study, with a view to investigate the biological function of PvGSTU3-3 a constitutive plant overexpression vector of PvGST3-3 was constructed and transferred into tobacco (Nicotiana tabacum. L. cv Xanthi) plants via A. tumefaciencs. The PvGSTU3-3 gene was successfully integrated into the genome of the transgenic tobacco lines as confirmed by Real time PCR and expressed in the transformants, validated through quantitative reverse transcription PCR. Three tobacco transgenic lines overexpressing PvGSTU3-3 tested for their salt tolerance (200mM NaCl) under in vitro conditions. All lines were more tolerant compared to wt plants, as demonstrated by the increased root length. These results suggest that PvGSTU3-3 isoenzyme can mediate physiological pathways that enhance salt stress tolerance

    Supervised learning based multimodal MRI brain tumour segmentation using texture features from supervoxels

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    BACKGROUND: Accurate segmentation of brain tumour in magnetic resonance images (MRI) is a difficult task due to various tumour types. Using information and features from multimodal MRI including structural MRI and isotropic (p) and anisotropic (q) components derived from the diffusion tensor imaging (DTI) may result in a more accurate analysis of brain images. METHODS: We propose a novel 3D supervoxel based learning method for segmentation of tumour in multimodal MRI brain images (conventional MRI and DTI). Supervoxels are generated using the information across the multimodal MRI dataset. For each supervoxel, a variety of features including histograms of texton descriptor, calculated using a set of Gabor filters with different sizes and orientations, and first order intensity statistical features are extracted. Those features are fed into a random forests (RF) classifier to classify each supervoxel into tumour core, oedema or healthy brain tissue. RESULTS: The method is evaluated on two datasets: 1) Our clinical dataset: 11 multimodal images of patients and 2) BRATS 2013 clinical dataset: 30 multimodal images. For our clinical dataset, the average detection sensitivity of tumour (including tumour core and oedema) using multimodal MRI is 86% with balanced error rate (BER) 7%; while the Dice score for automatic tumour segmentation against ground truth is 0.84. The corresponding results of the BRATS 2013 dataset are 96%, 2% and 0.89, respectively. CONCLUSION: The method demonstrates promising results in the segmentation of brain tumour. Adding features from multimodal MRI images can largely increase the segmentation accuracy. The method provides a close match to expert delineation across all tumour grades, leading to a faster and more reproducible method of brain tumour detection and delineation to aid patient management

    Early Major Worsening in Ischemic Stroke: Predictors and Outcome

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    Introduction: We aimed to investigate the characteristics and outcome of patients suffering early major worsening (EMW) after acute ischemic stroke (AIS) and assess the parameters associated with it. Methods: All consecutive patients with AIS in the ASTRAL registry until 10/2010 were included. EMW was defined as an NIHSS increase of ≥8 points within the first 24h after admission. The Bootstrap version of the Kolmogorov-Smirnov test and the χ 2-test were used for the comparison of continuous and categorical covariates, respectively, between patients with and without EMW. Multiple logistic regression analysis was performed to identify independent predictors of EMW. Results: Among 2155 patients, 43 (2.0%) had an EMW. EMW was independently associated with hemorrhagic transformation (OR 22.6, 95% CI 9.4-54.2), cervical artery dissection (OR 9.5, 95% CI 4.4-20.6), initial dysarthria (OR 3.7, 95% CI 1.7-8.0), and intravenous thrombolysis (OR 2.1, 95% CI 1.1-4.3), whereas a negative association was identified with initial eye deviation (OR 0.4, 95% CI 0.2-0.9). Favorable outcome at 3 and 12months was less frequent in patients with EMW compared to patients without (11.6 vs. 55.3% and 16.3 vs. 50.7%, respectively), and case fatality was higher (53.5 vs. 12.9% and 55.8 vs. 16.8%, respectively). Stroke recurrence within 3months in surviving patients was similar between patients with and without EMW (9.3 vs. 9.0%, respectively). Conclusions: Worsening of ≥8 points in the NIHSS score during the first 24h in AIS patients is related to cervical artery dissection and hemorrhagic transformation. It justifies urgent repeat parenchymal and arterial imaging. Both conditions may be influenced by targeted interventions in the acute phase of strok

    Patients with Neovascular Age-Related Macular Degeneration Requiring Intensive Intravitreal Aflibercept Treatment: An ARIES Post Hoc Analysis.

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    INTRODUCTION The aim of this post hoc analysis of the ARIES study is to explore the requirement for intravitreal aflibercept (IVT-AFL) treatment intervals of < 8 weeks (w) in patients with neovascular age-related macular degeneration (nAMD), and to assess vision and anatomic outcomes in such patients who require more intensive treatment. METHODS ARIES was a multicenter, randomized, phase 3b/4 study that investigated the efficacy of two IVT-AFL proactive, individualized, treat-and-extend regimens over 2 years in treatment-naïve patients with nAMD. Patients were determined as injection-intensive if the study investigator identified that a treatment interval of < 8 w was needed and if they had ≥ 1 interval of < 8 w after three initial monthly doses. Treatment intervals could be extended subsequently if extension criteria were met. This is a post hoc analysis of patients enrolled in ARIES and statistical analysis is descriptive. RESULTS Of 269 patients in the combined treatment arms, 23.0% (n = 62) were injection-intensive (Year 1: 13.8% [n = 37]; Year 2: 9.3% [n = 25]). Time from IVT-AFL initiation to injection-intensive determination varied (range, 16-100 w; median: 43.2 w). Mean treatment interval was 8.4 w before and 6.1 w after injection-intensive determination. Overall, 59.7% achieved treatment intervals of ≥ 8 w following injection-intensive determination. Vision improvements from baseline to Week 104 were smaller for injection-intensive patients than non-injection-intensive patients (mean [SD] best-corrected visual acuity change: + 2.3 [15.6] vs.  + 5.9 [12.3] letters). Anatomic outcomes were similar between injection-intensive and non-injection-intensive patients (central retinal thickness change from baseline to Week 104: - 160 [154] vs.  - 167 [136] µm). CONCLUSIONS In ARIES, 23% of treatment-naïve patients with nAMD experienced at least one treatment interval of < 8 w. Injection-intensive patients showed improved vision and anatomic outcomes. For most, treatment intervals could be extended to ≥ 8 w following injection-intensive determination. CLINICALTRIALS gov Identifier: NCT02581891

    Association Between Visual Acuity and Fluid Compartments with Treat-and-Extend Intravitreal Aflibercept in Neovascular Age-Related Macular Degeneration: An ARIES Post Hoc Analysis.

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    INTRODUCTION Recently, there has been growing interest in exploring the relationship between visual acuity and fluid localization in different retinal compartments. This post hoc analysis of the ARIES study explores the relationship between the presence of intraretinal fluid (IRF) and subretinal fluid (SRF), both at baseline and throughout treatment, and best-corrected visual acuity (BCVA) in patients with neovascular age-related macular degeneration (nAMD) treated with intravitreal aflibercept (IVT-AFL) in a treat-and-extend regimen. METHODS ARIES (NCT02581891) was a multicenter, randomized, phase 3b/4 study comparing the efficacy of two IVT-AFL treat-and-extend regimens over 2 years in patients with treatment-naïve nAMD. This post hoc analysis explores the relationship between the presence of SRF/IRF and absolute BCVA (letter score) at baseline and fixed visits. RESULTS In 210 patients (treat-and-extend treatment arms combined), SRF presence at baseline was associated at every time point with a numerically higher mean BCVA than if absent, with 10 more letters at week 104. IRF presence at baseline was associated at all but one time point with a numerically lower mean BCVA than if absent (week 104, 8-letter difference). Baseline SRF+IRF was associated with lower BCVA (week 104, 7-letter difference) than if only SRF was present, but higher BCVA (week 104, 8-letter difference) than if only IRF was present. Absence of SRF+IRF was not associated with better BCVA at any time point during the study. CONCLUSION In ARIES, in patients with nAMD treated with IVT-AFL, the presence of SRF was associated with better visual acuity, whereas IRF was associated with poorer visual acuity. The findings of this post hoc analysis suggest that differentiating IRF from SRF may offer better prognostic value in guiding treatment-extension decisions than the use of combined or "any" IRF and SRF. Prospective trials are needed to validate these results and determine their clinical relevance. TRIAL REGISTRATION NUMBER (CLINICALTRIALS.GOV): NCT02581891. Association between Visual Acuity and Fluid Compartments with Treat-and-Extend Intravitreal Aflibercept in Neovascular Age-Related Macular Degeneration: An ARIES Post Hoc Analysis: A Video Abstract (MP4 308264 KB)

    The impact of the COVID-19 pandemic on the learning and wellbeing of secondary school students: a survey in Southern Europe

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    The transition from the traditional model of learning and teaching to full online mode had to be implemented in many countries, in an extremely short time, as the 2020-2021 school year was in mid-stream. Secondary education, which includes students in the age range of 12-18, faced many challenges in this rapid change, as many research studies have shown. Researchers raise questions regarding the readiness of the secondary education community to transition to fully online learning. The pilot study reported in this paper deals with the impact of the transition to online learning on secondary schools in southern European countries. More specifically, this paper presents the results of a literature survey and an empirical survey using an online questionnaire which captured non-traceable responses from secondary schools that, voluntarily and anonymously, completed the questionnaire. The questions were mainly closed, with some open-ended questions for students to fill in. The study also aims to capture data on the socio-economic dimension, accessibility/ availability of the necessary technologies that enable online learning, as well as the families’ employment status and their ability to support students. A total of 90 students participated (62% female, 28% male) from three Mediterranean countries. The students’ perspectives as seen by the students themselves along with the difficulties and the issues they faced are compared and contrasted. This investigation offers a pedagogical and socio-technical analysis and highlights the needs for wellbeing as well as quality learning and teaching in the new social distance reality

    Subjective Cognitive Decline Higher Among Sexual and Gender Minorities in the United States, 2015–2018

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    Introduction: Subjective cognitive decline (SCD) represents self-reported problems with memory, a possible early sign of dementia. Little is known about SCD among sexual and gender minority (SGM) adults who identify as lesbian, gay, bisexual, and/or transgender or gender non-binary. Methods: Data were weighted to represent population estimates from 25 states’ 2015–2018 Behavioral Risk Factor Surveillance System to describe SCD in adults ≥ 45 years by SGM status. Logistic regression tested associations between demographic and health conditions. Results: SCD prevalence was higher in SGM (15.7%; 95% confidence interval [CI]:13.1–18.2) than in non-SGM adults (10.5%; 95% CI:10.1–10.9; P \u3c .0001). SGM adults with SCD were also more likely to report functional limitations due to SCD than non-SGM adults with SCD, 60.8% versus 47.8%, P =.0048. Differences in SCD by SGM status were attenuated after accounting for depression. Discussion: Higher prevalence of SCD in SGM adults highlights the importance of ensuring inclusive screenings, interventions, care services, and resources for SGM adults
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