Phase analysis detects heterogeneity of myocardial deformation on cine MRI

Abstract Objectives. Myocardial scar will lead to heterogeneous left ventricular deformation. We hypothesized that a myocardial scar will display an elevated standard deviation of phase and that this effect could be compared with mechanical dispersion. Design. Thirty patients (3 women and 27 men) were investigated 4-8 weeks after ST-elevation myocardial infarction treated with percutaneous coronary intervention. Seventeen had a scar area >75% in at least one antero- or inferoseptal segment (scar) and 13 had scar <1% (non-scar). The phase delays of velocity, displacement and strain were measured in the longitudinal direction, tangential to the endocardial outline, and in the radial direction, perpendicular to the tangent. Results. The standard deviation of phase in radial measurements differentiated scar patients from those without scar (p<0.01), while longitudinal measurements did so only for longitudinal strain. Likewise, the standard deviation for radial measurements of time to peak for segmental velocity, displacement and strain performed better than longitudinal measurements and equal to the results of phase. Conclusion. Phase dispersion in deformation imaging may be used for detecting heterogeneous left ventricular contraction

Phase analysis detects heterogeneity of myocardial deformation on cine MRI

Abstract Objectives. Myocardial scar will lead to heterogeneous left ventricular deformation. We hypothesized that a myocardial scar will display an elevated standard deviation of phase and that this effect could be compared with mechanical dispersion. Design. Thirty patients (3 women and 27 men) were investigated 4-8 weeks after ST-elevation myocardial infarction treated with percutaneous coronary intervention. Seventeen had a scar area >75% in at least one antero- or inferoseptal segment (scar) and 13 had scar <1% (non-scar). The phase delays of velocity, displacement and strain were measured in the longitudinal direction, tangential to the endocardial outline, and in the radial direction, perpendicular to the tangent. Results. The standard deviation of phase in radial measurements differentiated scar patients from those without scar (p<0.01), while longitudinal measurements did so only for longitudinal strain. Likewise, the standard deviation for radial measurements of time to peak for segmental velocity, displacement and strain performed better than longitudinal measurements and equal to the results of phase. Conclusion. Phase dispersion in deformation imaging may be used for detecting heterogeneous left ventricular contraction

Insect pathogenicity in plant-beneficial pseudomonads: phylogenetic distribution and comparative genomics.

Bacteria of the genus Pseudomonas occupy diverse environments. The Pseudomonas fluorescens group is particularly well-known for its plant-beneficial properties including pathogen suppression. Recent observations that some strains of this group also cause lethal infections in insect larvae, however, point to a more versatile ecology of these bacteria. We show that 26 P. fluorescens group strains, isolated from three continents and covering three phylogenetically distinct sub-clades, exhibited different activities toward lepidopteran larvae, ranging from lethal to avirulent. All strains of sub-clade 1, which includes Pseudomonas chlororaphis and Pseudomonas protegens, were highly insecticidal regardless of their origin (animals, plants). Comparative genomics revealed that strains in this sub-clade possess specific traits allowing a switch between plant- and insect-associated lifestyles. We identified 90 genes unique to all highly insecticidal strains (sub-clade 1) and 117 genes common to all strains of sub-clade 1 and present in some moderately insecticidal strains of sub-clade 3. Mutational analysis of selected genes revealed the importance of chitinase C and phospholipase C in insect pathogenicity. The study provides insight into the genetic basis and phylogenetic distribution of traits defining insecticidal activity in plant-beneficial pseudomonads. Strains with potent dual activity against plant pathogens and herbivorous insects have great potential for use in integrated pest management for crops