Early detection of reduced left ventricular systolic function by 2D speckle tracking echocardiography in patients with primary mitral regurgitation in a Vietnamese cohort.

Background: Mitral regurgitation (MR) is a common heart valve disease, causing many serious complications in several organ systems, especially the cardiovascular system. The 2D speckle tracking echocardiography (STE) is a new technique for detecting potential cardiac dysfunction when only tissue function abnormalities are present. The study aimed to assess left ventricular (LV) systolic function early by STE in patients with primary MR through global LV deformity along the global longitudinal strain (GLS). Methods: An analytical cross-sectional study was performed on 46 patients with moderate to severe primary MR as recommended by the American Society of Echocardiography (ASE) 2017. Results: The prevalence of patients with GLS reduction with ejection fraction (EF) >60%, New York Heart Association (NYHA) I, and left ventricular internal diameter systolic (LVIDs) <40 mm was 38.1%, 35.7%, and 39.5%, respectively. 100% of patients with EF<60% and LVIDs ≥40 mm had reduced GLS (<16%). The GLS index strongly correlates with the NYHA classification, degree of MR, EF, and echocardiographic parameters. Conclusion: GLS index gives a significant sign in the early detection of cardiac function abnormalities before symptoms or other echocardiographic parameters in patients with MR.

Spatial structure and richness of ectomycorrhizal fungi colonizing bioassay seedlings from resistant propagules in a Sierra Nevada forest: comparisons using two hosts that exhibit different seedling establishment patterns.

In this study we analyzed the spatial structure of ectomycorrhizal fungi present in the soils as resistant propagules (e.g. spores or sclerotia) in a mixed-conifer forest in the Sierra Nevada, California. Soils were collected under old-growth Abies spp. stands across approximately 1 km and bioassayed with seedlings of hosts that establish best in stronger light (Pinus jeffreyi) or that are shade-tolerant (Abies concolor). Ectomycorrhizal fungi colonizing the roots were characterized with molecular techniques (ITSRFLP and DNA sequence analysis). Wilcoxina, five Rhizopogon species and Cenococcum were the most frequent of 17 detected species. No spatial structure was detected in the resistant propagule community as a whole, but P. jeffreyi seedlings had higher species richness and associated with seven Rhizopogon species that were not detected on A. concolor seedlings. We drew two conclusions from comparisons between this study and a prior study of the ectomycorrhizal community on mature trees in the same forest: (i) the resistant propagule community was considerably simpler and more homogeneous than the active resident community across the forest and (ii) Cenococcum and Wilcoxina species are abundant in both communities.