10 research outputs found

    Tomato leaf curl geminivirus in Australia: occurrence, detection, sequence diversity and host range

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    The occurrence of whitefly transmitted geminiviruses in Australia was studied using a mixed DNA probe capable of detecting a range of distinct geminiviruses. The only geminivirus species detected was Tomato leaf curl virus (TLCV), which is spread across a vast geographical region of far-northern coastal Australia, an area inhabited by the Australasian-Oceania biotype of Bemisia tabaci. The newly introduced silverleaf whitefly, B. tabaci biotype B, forms high population densities in the eastern coastal region of Queensland and is currently located approximately 150 km from the nearest known TLCV-infected area. The viral host range appeared to be narrow and of 58 species of crop plants and weeds inoculated using the B biotype, only 11 became infected with the virus, including five that did not show foliar symptoms. A DNA fragment of 694 nt, including the complete C4 open reading frame (ORF), the overlapping N-terminal part of the C1 ORF and the viral iterons involved in replication, was amplified from 11 TLCV field isolates and sequenced. Sequence analysis revealed an overall sequence variation of up to 14% in this region, as well as the presence of distinct viral iterons

    Tomato leaf curl geminivirus in Australia: occurrence, detection, sequence diversity and host range

    No full text
    The occurrence of whitefly transmitted geminiviruses in Australia was studied using a mixed DNA probe capable of detecting a range of distinct geminiviruses. The only geminivirus species detected was Tomato leaf curl virus (TLCV), which is spread across a vast geographical region of far-northern coastal Australia, an area inhabited by the Australasian-Oceania biotype of Bemisia tabaci. The newly introduced silverleaf whitefly, B. tabaci biotype B, forms high population densities in the eastern coastal region of Queensland and is currently located approximately 150 km from the nearest known TLCV-infected area. The viral host range appeared to be narrow and of 58 species of crop plants and weeds inoculated using the B biotype, only 11 became infected with the virus, including five that did not show foliar symptoms. A DNA fragment of 694 nt, including the complete C4 open reading frame (ORF), the overlapping N-terminal part of the C1 ORF and the viral iterons involved in replication, was amplified from 11 TLCV field isolates and sequenced. Sequence analysis revealed an overall sequence variation of up to 14% in this region, as well as the presence of distinct viral iterons

    The correlation between cardiac magnetic resonance T2* and left ventricular global longitudinal strain in people with β-thalassemia

    No full text
    Background: Heart failure is the biggest cause of mortality and morbidity in people with thalassemia, and iron deposition in cardiac tissue impairs cardiovascular function. Therefore, early detection of cardiac involvement is important to improve the prognosis in these individuals. Method: Two- and three-dimensional echocardiography was performed to evaluate left ventricular ejection fraction (LVEF), left ventricular volumes and diameters, and global longitudinal strain (GLS) in 130 individuals with β-thalassemia using the speckle tracking method. Magnetic resonance imaging (MRI) was carried out on both the heart and liver. The participants were divided into 2 groups based on cardiac T2* values (normal and abnormal cardiac iron load), and the correlation between cardiac T2* MRI and GLS was evaluated. Results: The statistical analysis showed a significant correlation between cardiac T2* MRI and left ventricular global longitudinal strain. There was a significant difference in global longitudinal strain (P <.0001), liver MRI T2*(P <.0001), and left ventricular ejection fraction (P <.001) between the 2 groups. The optimal cutoff value for GLS was �18.5 with sensitivity and specificity 73.0 and 63.0, respectively (postitive predictive value = 50, negative predictive value = 82.3, AUC = 0.742, std. error = 0.046) which predicts T2* value of <20 ms, according to cardiac MRI. Conclusions: The participants with cardiac iron overload had a lower GLS than those without one. This suggests that GLS may be a useful method to predict myocardial iron overload particularly in β-thalassemia patients with subclinical cardiac involvement. © 2018, Wiley Periodicals, Inc

    The correlation between cardiac magnetic resonance T2* and left ventricular global longitudinal strain in people with β-thalassemia

    No full text
    Background: Heart failure is the biggest cause of mortality and morbidity in people with thalassemia, and iron deposition in cardiac tissue impairs cardiovascular function. Therefore, early detection of cardiac involvement is important to improve the prognosis in these individuals. Method: Two- and three-dimensional echocardiography was performed to evaluate left ventricular ejection fraction (LVEF), left ventricular volumes and diameters, and global longitudinal strain (GLS) in 130 individuals with β-thalassemia using the speckle tracking method. Magnetic resonance imaging (MRI) was carried out on both the heart and liver. The participants were divided into 2 groups based on cardiac T2* values (normal and abnormal cardiac iron load), and the correlation between cardiac T2* MRI and GLS was evaluated. Results: The statistical analysis showed a significant correlation between cardiac T2* MRI and left ventricular global longitudinal strain. There was a significant difference in global longitudinal strain (P <.0001), liver MRI T2*(P <.0001), and left ventricular ejection fraction (P <.001) between the 2 groups. The optimal cutoff value for GLS was �18.5 with sensitivity and specificity 73.0 and 63.0, respectively (postitive predictive value = 50, negative predictive value = 82.3, AUC = 0.742, std. error = 0.046) which predicts T2* value of <20 ms, according to cardiac MRI. Conclusions: The participants with cardiac iron overload had a lower GLS than those without one. This suggests that GLS may be a useful method to predict myocardial iron overload particularly in β-thalassemia patients with subclinical cardiac involvement. © 2018, Wiley Periodicals, Inc
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