97 research outputs found

    Maternal effect on thermotolerance in lettuce seeds

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    O objetivo deste trabalho foi avaliar a ocorrência do efeito materno na tolerância à termoinibição em sementes de alface (Lactuca sativa), bem como encontrar um marcador enzimático para esta característica em mudas de alface. Foram utilizadas sementes da cultivar termotolerante Everglades, da cultivar suscetível Verônica e de seus híbridos recíprocos. Para cada cultivar e híbrido recíproco, foram conduzidos testes de germinação e vigor (índice de velocidade de germinação) a 20 e 32°C. A termotolerância foi definida pela capacidade de germinação a 32°C. Para encontrar marcadores que pudessem ser associados com a termotolerância, foram realizados testes enzimáticos. As bandas eletroforéticas dos extratos enzimáticos foram quantificadas por meio do programa ImageJ. Os híbridos apresentaram comportamento semelhante ao dos seus genitores femininos. Quando a cultivar Verônica foi o genitor feminino, as sementes dos híbridos não germinaram sob alta temperatura e apresentaram menor expressão da enzima esterase. Porém, quando a cultivar Everglades foi o genitor feminino, os híbridos apresentaram alta germinação sob temperatura elevada e maior expressão da esterase. Portanto, há efeito materno na tolerância à termoinibição em sementes de alface, e a enzima esterase apresenta potencial como marcador para identificar progênies homozigotas para essa característica.The objective of this work was to evaluate the occurrence of the maternal effect on thermotolerance in lettuce (Lactuca sativa) seeds, as well as to find an enzymatic marker for this trait in lettuce seedlings. Seeds from the Everglades thermotolerant cultivar, the Verônica susceptible cultivar, and their reciprocal hybrids were used. For each cultivar and reciprocal hybrid, germination percentage and vigor (germination speed index) tests were carried out at 20 and 32°C. Thermotolerance was defined as the capacity to germinate at 32°C. To obtain markers that could be associated with thermotolerance, enzymatic tests were performed. The bands of the electrophoretic enzymatic extracts were quantified using the ImageJ software. The hybrids behaved similarly to their female genitors. When cultivar Verônica was the female genitor, hybrid seeds did not germinate at high temperatures and showed a lower expression of the esterase enzyme. However, when the female genitor was the Everglades cultivar, hybrids showed a high germination at high temperatures and a greater esterase expression. Therefore, there is a maternal effect on tolerance to thermoinhibition in lettuce seeds, and the esterase enzyme can be used as a selective marker to identify homozygous progenies for this trait

    Microenxertia ex vitro para eliminação do vírus CABMV em maracujá-azedo

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    The objective of this work was to evaluate the effect of different culture media, used over grafting spot, in ex vitro micrografting, in order to eliminate the Cowpea aphid-borne mosaic virus (CABMV) in sour passion fruit plants (Passiflora edulis Sims f. flavicarpa Deg.). Cauline apexes, originated from infected plants, were micrografted in seedlings obtained by the germination of seeds in commercial sterilized substrate. Experiments were conducted with the micrografting performed on the hypocotyl and epicotyl using five culture media, which differed on their concentration of phytoregulators applied on the grafting spot. The average rate of micrografting showing expanded leaf was 27.22 and 32.22%, when micrografting was performed on hypocotyl and epicotyl, respectively. In the micrografting performed on the hypocotyl, there was no effect of the culture media applied. In the micrografting performed on epicotyl, the MS medium supplemented with 0.1 mg L-1 3-indolbutiric acid (IBA) and 1 mg L-1 6-benzylaminopurine (BAP) resulted in 53.3% of micrografting showing expanded leaf, a number superior to the other treatments, and in a larger development of shoots. The indexing performed by the indirect ELISA test, within 80 to 100 days after micrografting, showed that 93% of the plants tested presented no detectable virus.O objetivo deste trabalho foi avaliar diferentes meios de cultura, utilizados sobre o ponto da enxertia, na microenxertia ex vitro para a eliminação do Cowpea aphid-borne mosaic virus (CABMV), em plantas de maracujá-azedo (Passiflora edulis Sims f. flavicarpa Deg.). Ápices caulinares, provenientes de plantas infectadas, foram microenxertados em plântulas obtidas pela germinação de sementes em substrato comercial esterilizado. Foram conduzidos experimentos com a microenxertia realizada no hipocótilo e no epicótilo, e foram utilizados cinco meios de cultura, que diferiam na concentração de fitorreguladores, aplicados no local da enxertia. O índice médio de microenxertos com folha expandida foi de 27,22 e 32,22%, quando a microenxertia foi realizada no hipocótilo e no epicótilo, respectivamente. Na microenxertia realizada no hipocótilo, não houve efeito da aplicação de meios de cultura. Na microenxertia realizada no epicótilo, o meio MS acrescido de 0,1 mg L-1 de AIB e 1 mg L-1 de BAP proporcionou 53,3% de microenxertos com folha expandida, número superior aos demais tratamentos e maior desenvolvimento das brotações. A indexação realizada pelo teste ELISA indireto, 80 a 100 dias após a microenxertia, mostrou que 93% das plantas testadas não apresentavam vírus detectável

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

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    Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

    Improved risk stratification of patients with atrial fibrillation: an integrated GARFIELD-AF tool for the prediction of mortality, stroke and bleed in patients with and without anticoagulation.

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    OBJECTIVES: To provide an accurate, web-based tool for stratifying patients with atrial fibrillation to facilitate decisions on the potential benefits/risks of anticoagulation, based on mortality, stroke and bleeding risks. DESIGN: The new tool was developed, using stepwise regression, for all and then applied to lower risk patients. C-statistics were compared with CHA2DS2-VASc using 30-fold cross-validation to control for overfitting. External validation was undertaken in an independent dataset, Outcome Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). PARTICIPANTS: Data from 39 898 patients enrolled in the prospective GARFIELD-AF registry provided the basis for deriving and validating an integrated risk tool to predict stroke risk, mortality and bleeding risk. RESULTS: The discriminatory value of the GARFIELD-AF risk model was superior to CHA2DS2-VASc for patients with or without anticoagulation. C-statistics (95% CI) for all-cause mortality, ischaemic stroke/systemic embolism and haemorrhagic stroke/major bleeding (treated patients) were: 0.77 (0.76 to 0.78), 0.69 (0.67 to 0.71) and 0.66 (0.62 to 0.69), respectively, for the GARFIELD-AF risk models, and 0.66 (0.64-0.67), 0.64 (0.61-0.66) and 0.64 (0.61-0.68), respectively, for CHA2DS2-VASc (or HAS-BLED for bleeding). In very low to low risk patients (CHA2DS2-VASc 0 or 1 (men) and 1 or 2 (women)), the CHA2DS2-VASc and HAS-BLED (for bleeding) scores offered weak discriminatory value for mortality, stroke/systemic embolism and major bleeding. C-statistics for the GARFIELD-AF risk tool were 0.69 (0.64 to 0.75), 0.65 (0.56 to 0.73) and 0.60 (0.47 to 0.73) for each end point, respectively, versus 0.50 (0.45 to 0.55), 0.59 (0.50 to 0.67) and 0.55 (0.53 to 0.56) for CHA2DS2-VASc (or HAS-BLED for bleeding). Upon validation in the ORBIT-AF population, C-statistics showed that the GARFIELD-AF risk tool was effective for predicting 1-year all-cause mortality using the full and simplified model for all-cause mortality: C-statistics 0.75 (0.73 to 0.77) and 0.75 (0.73 to 0.77), respectively, and for predicting for any stroke or systemic embolism over 1 year, C-statistics 0.68 (0.62 to 0.74). CONCLUSIONS: Performance of the GARFIELD-AF risk tool was superior to CHA2DS2-VASc in predicting stroke and mortality and superior to HAS-BLED for bleeding, overall and in lower risk patients. The GARFIELD-AF tool has the potential for incorporation in routine electronic systems, and for the first time, permits simultaneous evaluation of ischaemic stroke, mortality and bleeding risks. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier for GARFIELD-AF (NCT01090362) and for ORBIT-AF (NCT01165710)

    Two-year outcomes of patients with newly diagnosed atrial fibrillation: results from GARFIELD-AF.

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    AIMS: The relationship between outcomes and time after diagnosis for patients with non-valvular atrial fibrillation (NVAF) is poorly defined, especially beyond the first year. METHODS AND RESULTS: GARFIELD-AF is an ongoing, global observational study of adults with newly diagnosed NVAF. Two-year outcomes of 17 162 patients prospectively enrolled in GARFIELD-AF were analysed in light of baseline characteristics, risk profiles for stroke/systemic embolism (SE), and antithrombotic therapy. The mean (standard deviation) age was 69.8 (11.4) years, 43.8% were women, and the mean CHA2DS2-VASc score was 3.3 (1.6); 60.8% of patients were prescribed anticoagulant therapy with/without antiplatelet (AP) therapy, 27.4% AP monotherapy, and 11.8% no antithrombotic therapy. At 2-year follow-up, all-cause mortality, stroke/SE, and major bleeding had occurred at a rate (95% confidence interval) of 3.83 (3.62; 4.05), 1.25 (1.13; 1.38), and 0.70 (0.62; 0.81) per 100 person-years, respectively. Rates for all three major events were highest during the first 4 months. Congestive heart failure, acute coronary syndromes, sudden/unwitnessed death, malignancy, respiratory failure, and infection/sepsis accounted for 65% of all known causes of death and strokes for <10%. Anticoagulant treatment was associated with a 35% lower risk of death. CONCLUSION: The most frequent of the three major outcome measures was death, whose most common causes are not known to be significantly influenced by anticoagulation. This suggests that a more comprehensive approach to the management of NVAF may be needed to improve outcome. This could include, in addition to anticoagulation, interventions targeting modifiable, cause-specific risk factors for death. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P &lt; 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    Maturation and Desiccation Tolerance in Seeds of Sesbania virgata (Cav.) Pers.

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    ABSTRACT The maturation process of Sesbania virgata seeds was investigated through fruits and seeds at different maturation stages, where they were described morphologically. For the seeds, fresh and dry mass and moisture were determined and structural analysis of the tegument under a light microscope was performed. Germination tests in the presence and absence of drying and the electrophoretic profile of heat resistant proteins were also performed. The results showed that the seeds reached physiological maturity at 44 days after anthesis (DAA), evidencing a secondary cell wall. The acquisition of desiccation tolerance was observed at 44 DAA, with the seeds responding to the drying treatment. Protein bands were observed from 32 DAA, which remained constant until the end of maturation. These results allowed the characterization of the development and acquisition of desiccation tolerance in S. virgata seeds
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