280 research outputs found

    First Report of Tomato yellow leaf curl virus in Tomato in Costa Rica

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    One of the most important invasive and harmful members of the genus Begomovirus (family Geminiviridae) is the monopartite Tomato yellow leaf curl virus (TYLCV), which is widespread over the world associated with tomato yellow leaf curl disease (TYLCD). Tomato (Solanum lycopersicum) plants infected with TYLCV show upward leaf curling and yellowing. In Latin America, isolates of TYLCV have been reported from Cuba, the Dominican Republic, Mexico and Puerto Rico (1), Guatemala (GenBank Accession No. GU355941), and Venezuela (partial genome sequence DQ302033). In Costa Rica, only isolates of the bipartite begomoviruses Tomato leaf curl Sinaloa virus (TLCSiV) (3) and Tomato yellow mottle virus (KC176780, KC176781) have been reported infecting tomatoes. During a survey conducted in 2012, similar begomovirus-like symptoms (leaf yellowing and upward leaf curling) were observed in tomato plants of five commercial growing areas in the Central Valley (Grecia region) of Costa Rica. In total, 65 tomato samples were randomly collected, 14 from greenhouses and 41 from open fields. Symptoms of upward leaf curling and yellowing were observed in three samples. Total DNA was extracted from collected samples and tested by dot blot hybridization using a probe to the coat protein (CP) gene of a Guatemalan isolate of Bean golden yellow mosaic virus (3). Only the three symptomatic samples tested positive, which represents an incidence of 14% (2 samples) in greenhouses and 2.4% (1 sample) in open field crops. These samples were subjected to rolling circle amplification (RCA) for viral circular genome amplification (2). The amplified products were then digested with MspI restriction endonuclease, which resulted into DNA fragments of 2,320 and 458 bp for all three samples. This suggested infection with a monopartite begomovirus. In order to obtain the full-length clone, the RCA product of two samples (5240 and 5241) was digested with BamHI, and the ~2.8 kb DNA fragment was cloned into pBluescript II SK(+) (Stratagene, La Jolla, CA) vector. After transformation of Escherichia coli DH5α, recombinant plasmids with inserts of expected size were selected and the insert was sequenced by primer walking (Macrogen Inc., Korea). The inserts of three clones from the two samples (CR:5240-16:2012, CR:5240-17:2012, and CR:5241-14:2012) were sequenced (deposited in GenBank as KF533855, KF533856, and KF533857, respectively). Sequences were all 2,781 nt long and shared 100% identity between themselves (1-nt mismatch between CR:5240-16:2012 and CR:5240-17:2012, and CR:5240-16:2012 and CR:5241-14:2012; and 2-nt mismatches between CR:5240-17:2012 and CR:5241-14:2012) and 99% with the sequence of Tomato yellow leaf curl virus-Israel[Japan:Haruno:2005] (TYLCV-IL[JR:Har:05]) (AB192966). These sequences represented full length genomes of isolates of the monopartite begomovirus TYLCV-IL and grouped in a phylogenetic clade (4) that comprised TYLCV-IL isolates reported from Asia (China and Japan) and from Mexico, while more distantly related to the clade comprising TYLCV-IL isolates reported from Central America (Cuba, Guatemala, Puerto Rico) and the United States, suggesting a distinct introduction event in Costa Rica. This is the first report of the presence of TYLCV in Costa Rica, therefore it is imperative to study the incidence and geographical spread of this virus in the country as well as its genetic diversity, since TYLCV infections might lead to significant yield losses, as reported in other countries.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM

    Annexin A6 Is Critical to Maintain Glucose Homeostasis and Survival During Liver Regeneration in Mice

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    Background and Aims: Liver regeneration requires the organized and sequential activation of events that lead to restoration of hepatic mass. During this process, other vital liver functions need to be preserved, such as maintenance of blood glucose homeostasis, balancing the degradation of hepatic glycogen stores, and gluconeogenesis (GNG). Under metabolic stress, alanine is the main hepatic gluconeogenic substrate, and its availability is the rate‐limiting step in this pathway. Na+‐coupled neutral amino acid transporters (SNATs) 2 and 4 are believed to facilitate hepatic alanine uptake. In previous studies, we demonstrated that a member of the Ca2+‐dependent phospholipid binding annexins, Annexin A6 (AnxA6), regulates membrane trafficking along endo‐ and exocytic pathways. Yet, although AnxA6 is abundantly expressed in the liver, its function in hepatic physiology remains unknown. In this study, we investigated the potential contribution of AnxA6 in liver regeneration. Approach and Results: Utilizing AnxA6 knockout mice (AnxA6−/−), we challenged liver function after partial hepatectomy (PHx), inducing acute proliferative and metabolic stress. Biochemical and immunofluorescent approaches were used to dissect AnxA6−/− mice liver proliferation and energetic metabolism. Most strikingly, AnxA6−/− mice exhibited low survival after PHx. This was associated with an irreversible and progressive drop of blood glucose levels. Whereas exogenous glucose administration or restoration of hepatic AnxA6 expression rescued AnxA6−/− mice survival after PHx, the sustained hypoglycemia in partially hepatectomized AnxA6−/− mice was the consequence of an impaired alanine‐dependent GNG in AnxA6−/− hepatocytes. Mechanistically, cytoplasmic SNAT4 failed to recycle to the sinusoidal plasma membrane of AnxA6−/− hepatocytes 48 hours after PHx, impairing alanine uptake and, consequently, glucose production. Conclusions: We conclude that the lack of AnxA6 compromises alanine‐dependent GNG and liver regeneration in mice

    What to consider when pseudohypoparathyroidism is ruled out: IPPSD and differential diagnosis

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    Background: Pseudohypoparathyroidism (PHP) is a rare disease whose phenotypic features are rather difficult to identify in some cases. Thus, although these patients may present with the Albright''s hereditary osteodystrophy (AHO) phenotype, which is characterized by small stature, obesity with a rounded face, subcutaneous ossifications, mental retardation and brachydactyly, its manifestations are somewhat variable. Indeed, some of them present with a complete phenotype, whereas others show only subtle manifestations. In addition, the features of the AHO phenotype are not specific to it and a similar phenotype is also commonly observed in other syndromes. Brachydactyly type E (BDE) is the most specific and objective feature of the AHO phenotype, and several genes have been associated with syndromic BDE in the past few years. Moreover, these syndromes have a skeletal and endocrinological phenotype that overlaps with AHO/PHP. In light of the above, we have developed an algorithm to aid in genetic testing of patients with clinical features of AHO but with no causative molecular defect at the GNAS locus. Starting with the feature of brachydactyly, this algorithm allows the differential diagnosis to be broadened and, with the addition of other clinical features, can guide genetic testing. Methods: We reviewed our series of patients (n = 23) with a clinical diagnosis of AHO and with brachydactyly type E or similar pattern, who were negative for GNAS anomalies, and classify them according to the diagnosis algorithm to finally propose and analyse the most probable gene(s) in each case. Results: A review of the clinical data for our series of patients, and subsequent analysis of the candidate gene(s), allowed detection of the underlying molecular defect in 12 out of 23 patients: five patients harboured a mutation in PRKAR1A, one in PDE4D, four in TRPS1 and two in PTHLH. Conclusions: This study confirmed that the screening of other genes implicated in syndromes with BDE and AHO or a similar phenotype is very helpful for establishing a correct genetic diagnosis for those patients who have been misdiagnosed with "AHO-like phenotype" with an unknown genetic cause, and also for better describing the characteristic and differential features of these less common syndromes

    Role of age and comorbidities in mortality of patients with infective endocarditis

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    Purpose: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. Methods: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015. Patients were stratified into three age groups:<65 years, 65 to 80 years, and = 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. Results: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 = 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients =80 years who underwent surgery were significantly lower compared with other age groups (14.3%, 65 years; 20.5%, 65-79 years; 31.3%, =80 years). In-hospital mortality was lower in the <65-year group (20.3%, <65 years;30.1%, 65-79 years;34.7%, =80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%, =80 years; p = 0.003).Independent predictors of mortality were age = 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI = 3 (HR:1.62; 95% CI:1.39–1.88), and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared, the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. Conclusion: There were no differences in the clinical presentation of IE between the groups. Age = 80 years, high comorbidity (measured by CCI), and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

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    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Overview of the JET ITER-like wall divertor

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    Power exhaust by SOL and pedestal radiation at ASDEX Upgrade and JET

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    Multi-machine scaling of the main SOL parallel heat flux width in tokamak limiter plasmas

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