Elucidating the native sources of an invasive tree species, Acacia pycnantha, reveals unexpected native range diversity and structure

† Background and Aims Understanding the introduction history of invasive plant species is important for their management and identifying effective host-specific biological control agents. However, uncertain taxonomy, intra- and interspecific hybridization, and cryptic speciation may obscure introduction histories, making it difficult to identify native regions to explore for host-specific agents. The overall aim of this study was to identify the native source populations of Acacia pycnantha, a tree native to south-eastern Australia and invasive in South Africa, Western Australia and Portugal. Using a phylogeographical approach also allowed an exploration of the historical processes that have shaped the genetic structure of A. pycnantha in its native range. † Methods Nuclear (nDNA) and plastid DNA sequence data were used in network and tree-building analyses to reconstruct phylogeographical relationships between native and invasive A. pycnantha populations. In addition, mismatch distributions, relative rates and Bayesian analyses were used to infer recent demographic processes and timing of events in Australia that led to population structure and diversification. † Key Results The plastid network indicated that Australian populations of A. pycnantha are geographically structured into two informally recognized lineages, the wetland and dryland forms, whereas the nuclear phylogeny showed little geographical structure between these two forms. Moreover, the dryland form of A. pycnantha showed close genetic similarity to the wetland form based on nDNA sequence data. Hybrid zones may explain these findings, supported here by incongruent phylogenetic placement of some of these taxa between nuclear and plastid genealogies. †Conclusions It is hypothesized that habitat fragmentation due to cycles of aridity inter-dispersed with periods of abundant rainfall during the Pleistocene (approx. 100 kya) probably gave rise to native dryland and wetland forms of A. pycnantha. Although the different lineages were confined to different ecological regions, we also found evidence for intraspecific hybridization in Victoria. The invasive populations in Portugal and South Africa represent wetland forms, whereas some South African populations resemble the Victorian dryland form. The success of the biological control programme for A. pycnantha in South Africa may therefore be attributed to the fact that the gall-forming wasp Trichilogaster signiventris was sourced from South Australian populations, which closely match most of the invasive populations in South Africa

DNA Topoisomerase 1α Promotes Transcriptional Silencing of Transposable Elements through DNA Methylation and Histone Lysine 9 Dimethylation in Arabidopsis

RNA-directed DNA methylation (RdDM) and histone H3K9 dimethylation (H3K9me2) are related transcriptional silencing mechanisms that target transposable elements (TEs) and repeats to maintain genome stability in plants. RdDM is mediated by small and long noncoding RNAs produced by the plant-specific RNA polymerases Pol IV and Pol V, respectively. Through a chemical genetics screen with a luciferase-based DNA methylation reporter, LUCL, we found that camptothecin, a compound with anti- cancer properties that targets DNA topoisomerase 1α (TOP1α) was able to de-repress LUCL by reducing its DNA methylation and H3K9me2 levels. Further studies with Arabidopsis top1α mutants showed that TOP1α silences endogenous RdDM loci by facilitating the production of Pol V-dependent long non-coding RNAs, AGONAUTE4 recruitment and H3K9me2 deposition at TEs and repeats. This study assigned a new role in epigenetic silencing to an enzyme that affects DNA topology.Fil: Dinh, Thanh Theresa. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados Unidos. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology. ChemGen IGERT program; Estados UnidosFil: Gao, Lei. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados UnidosFil: Liu, Xigang . University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados UnidosFil: Li, Dongming. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados Unidos. Lanzhou University. School of Life Sciences Plant Biology Laboratory; ChinaFil: Li, Shengben. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados UnidosFil: Zhao, Yuanyuan. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados UnidosFil: O'leary, Michael. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados UnidosFil: Le, Brandon. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados UnidosFil: Schmitz, Robert J.. The Salk Institute for Biological Studies. Plant Biology Laboratory; Estados UnidosFil: Manavella, Pablo Andrés. Max Planck Institute for Developmental Biology. Department of Molecular Biology; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Agrobiotecnologia del Litoral; ArgentinaFil: Li, Shaofang. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados UnidosFil: Weigel, Detlef. Max Planck Institute for Developmental Biology. Department of Molecular Biology; AlemaniaFil: Pontes, Olga. University of New Mexico. Department of Biology; Estados UnidosFil: Ecker, Joseph R.. The Salk Institute for Biological Studies. Howard Hughes Medical Institute; Estados Unidos. The Salk Institute for Biological Studies. Plant Biology Laboratory; Estados UnidosFil: Chen, Xuemei. University of California Riverside. Center for Plant Cell Biology, Institute of Integrative Genome Biology, Department of Botany and Plant Sciences; Estados Unidos. University of California Riverside. Howard Hughes Medical Institute, ; Estados Unido

Relationship between carotid intima-media thickness and coronary angiographic findings: a prospective study

<p>Abstract</p> <p>Background</p> <p>Since cardiovascular diseases are associated with high mortality and generally undiagnosed before the onset of clinical findings, there is a need for a reliable tool for early diagnosis. Carotid intima-media thickness (CIMT) is a non-invasive marker of coronary artery disease (CAD) and is widely used in practice as an inexpensive, reliable, and reproducible method. In the current study, we aimed to investigate prospectively the relationship of CIMT with the presence and extent of significant coronary artery narrowing in patients evaluated by coronary angiography for stable angina pectoris.</p> <p>Methods</p> <p>One hundred consecutive patients with stable angina pectoris and documented ischemia on a stress test were included in the study. The patients were divided into two groups according to the result of the coronary angiography: group 1 (39 patients) without a noncritical coronary lesion, and group 2 (61 patients) having at least one lesion more than 50% within the main branches of the coronary arteries. All of the patients underwent carotid Doppler ultrasound examination for measurement of the CIMT by a radiologist blinded to the angiographic data.</p> <p>Results</p> <p>The mean CIMT was 0.78 ± 0.21 mm in Group 1, while it was 1.48 ± 0.28 mm in Group 2 (p = 0.001). The mean CIMT in patients with single vessel disease, multi-vessel disease, and left main coronary artery disease were significantly higher compared to Group 1 (1.2 ± 0.34 mm, p = 0.02; 1.6 ± 0.32 mm, p = 0.001; and 1.8 ± 0.31 mm, p = 0.0001, respectively). Logistic regression analysis identified CIMT (OR 4.3, p < 0.001) and hypertension (OR 2.4, p = 0.04) as the most important factors for predicting CAD.</p> <p>Conclusions</p> <p>The findings of this study show that increase in CIMT is associated with the presence and extent of CAD. In conclusion, we demonstrated the usefulness of carotid intima-media thickness in predicting coronary artery disease but large-scale studies are required to define its role in clinical practice.</p

Sequentially based analysis versus image based analysis of Intima Media Thickness in common carotid arteries studies - Do major IMT studies underestimate the true relations for cardio- and cerebrovascular risk?

<p>Abstract</p> <p>Background</p> <p>Image-based B-mode ultrasound has gained popularity in major studies as a non-invasive method of measuring cardio- and cerebrovascular risk factors. However, none of the major studies appears to have paid sufficient attention to the variation in end diastolic wall process. By using sequentially based analyses (SBA) of Intima-Media Thickness (IMT), the general purpose of this study was to show that the current image based (ECG tracked) analysis (IBA) has some major variations and might underestimate the true relations for cardiovascular events and stroke for IMT measurement.</p> <p>Method</p> <p>The study group consisted of 2500 healthy male subjects aged between 35 to 55 years. 4 sequences (300 images) were analyzed per subject. 750,000 images were analysed throughout the course of this study.</p> <p>Results</p> <p>IBA showed significantly lower mean, maximal, and minimal values for IMT in CCA than for SBA. The correlation analysis between IBA and SBA with the cardio- and cerebrovascular risk factors showed a higher correlation of SBA for all risk factors. The Pearson coefficient was 0.81, p < 0.01, for SBA versus Framingham CHD risk level (FCRL) and 0.49, p = 0.01, for IBA versus FCRL.</p> <p>Conclusion</p> <p>IBA did not measure the true maximal values of the IMT in this study. Together with the correlation analysis, this indicates that IBA might underestimate the true relations for IMT and risk factors.</p

Prevalence of macrovascular disease amongst type 2 diabetic patients detected by targeted screening and patients newly diagnosed in general practice: the Hoorn Screening Study

Prevalence of macrovascular disease amongst type 2 diabetic patients detected by targeted screening and patients newly diagnosed in general practice: the Hoorn Screening Study. Spijkerman AM, Henry RM, Dekker JM, Nijpels G, Kostense PJ, Kors JA, Ruwaard D, Stehouwer CD, Bouter LM, Heine RJ. Institutes for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands. [email protected] OBJECTIVES: Screening for type 2 diabetes has been recommended and targeted screening might be an efficient way to screen. The aim was to investigate whether diabetic patients identified by a targeted screening procedure differ from newly diagnosed diabetic patients in general practice with regard to the prevalence of macrovascular complications. DESIGN: Cross-sectional population-based study. SETTING: Population study, primary care. SUBJECTS: Diabetic patients identified by a population-based targeted screening procedure (SDM patients), consisting of a screening questionnaire and a fasting capillary glucose measurement followed by diagnostic testing, were compared with newly diagnosed diabetic patients in general practice (GPDM patients). Ischaemic heart disease and prior myocardial infarction were assessed by ECG recording. Peripheral arterial disease was assessed by the ankle-arm index. Intima-media thickness of the right common carotid artery was measured with ultrasound. RESULTS: A total of 195 SDM patients and 60 GPDM patients participated in the medical examination. The prevalence of MI was 13.3% (95% CI 9.3-18.8%) and 3.4% (1.0-11.7%) in SDM patients and GPDM patients respectively. The prevalence of ischaemic heart disease was 39.5% (95% CI 32.9-46.5%) in SDM patients and 24.1% (15.0-36.5%) in GPDM patients. The prevalence of peripheral arterial disease was similar in both groups: 10.6% (95% CI 6.9-15.9%) and 10.2% (4.7-20.5%) respectively. Mean intima-media thickness was 0.85 mm (+/-0.17) in SDM patients and 0.90 mm (+/-0.20) in GPDM patients. The difference in intima-media thickness was not statistically significant. CONCLUSIONS: Targeted screening identified patients with a prevalence of macrovascular complications similar to that of patients detected in general practice, but with a lower degree of hyperglycaemi

Heart rate variability and target organ damage in hypertensive patients

Background: We evaluated the association between linear standard Heart Rate Variability (HRV) measures and vascular, renal and cardiac target organ damage (TOD). Methods: A retrospective analysis was performed including 200 patients registered in the Regione Campania network (aged 62.4 ± 12, male 64%). HRV analysis was performed by 24-h holter ECG. Renal damage was assessed by estimated glomerular filtration rate (eGFR), vascular damage by carotid intima-media thickness (IMT), and cardiac damage by left ventricular mass index. Results: Significantly lower values of the ratio of low to high frequency power (LF/HF) were found in the patients with moderate or severe eGFR (p-value < 0.001). Similarly, depressed values of indexes of the overall autonomic modulation on heart were found in patients with plaque compared to those with a normal IMT (p-value <0.05). These associations remained significant after adjustment for other factors known to contribute to the development of target organ damage, such as age. Moreover, depressed LF/HF was found also in patients with left ventricular hypertrophy but this association was not significant after adjustment for other factors. Conclusions: Depressed HRV appeared to be associated with vascular and renal TOD, suggesting the involvement of autonomic imbalance in the TOD. However, as the mechanisms by which abnormal autonomic balance may lead to TOD, and, particularly, to renal organ damage are not clearly known, further prospective studies with longitudinal design are needed to determine the association between HRV and the development of TOD

Carotid intimal-media thickness as a surrogate for cardiovascular disease events in trials of HMG-CoA reductase inhibitors

BACKGROUND: Surrogate measures for cardiovascular disease events have the potential to increase greatly the efficiency of clinical trials. A leading candidate for such a surrogate is the progression of intima-media thickness (IMT) of the carotid artery; much experience has been gained with this endpoint in trials of HMG-CoA reductase inhibitors (statins). METHODS AND RESULTS: We examine two separate systems of criteria that have been proposed to define surrogate endpoints, based on clinical and statistical arguments. We use published results and a formal meta-analysis to evaluate whether progression of carotid IMT meets these criteria for HMG-CoA reductase inhibitors (statins). IMT meets clinical-based criteria to serve as a surrogate endpoint for cardiovascular events in statin trials, based on relative efficiency, linkage to endpoints, and congruency of effects. Results from a meta-analysis and post-trial follow-up from a single published study suggest that IMT meets established statistical criteria by accounting for intervention effects in regression models. CONCLUSION: Carotid IMT progression meets accepted definitions of a surrogate for cardiovascular disease endpoints in statin trials. This does not, however, establish that it may serve universally as a surrogate marker in trials of other agents

HPV type-specific prevalence using a urine assay in unvaccinated male and female 11- to 18-year olds in Scotland

We conducted a baseline prevalence survey of unvaccinated 11- to 18-year olds to inform effectiveness studies for the new human papillomavirus (HPV) immunisation programme in Scotland

West Nile Virus Epidemic, Northeast Ohio, 2002

Serum samples and sociodemographic data were obtained from 1,209 Ohio residents. West Nile virus immunoglobulin M (IgM) and IgG antibodies were detected by enzyme-linked immunosorbent assay and confirmed. Children were 4.5 times more likely to become infected yet 110× less likely to have neuroinvasive disease develop