2DE Images Research Articles

2D and 3D Echocardiography-Derived Indices of Left Ventricular Function and Shape: Relationship With Mortality

ObjectivesThis study hypothesized that left ventricular (LV) ejection fraction (EF) and global longitudinal strain (GLS) derived from 3-dimensional echocardiographic (3DE) images would better predict mortality than those obtained by 2-dimensional echocardiographic (2DE) measurements, and that 3DE-based LV shape analysis may have added prognostic value. BackgroundPrevious studies have shown that both LVEF and GLS derived from 2DE images predict mortality. Recently, 3DE measurements of these parameters were found to be more accurate and reproducible because of independence of imaging plane and geometric assumptions. Also, 3DE analysis offers an opportunity to accurately quantify LV shape. MethodsWe retrospectively studied 416 inpatients (60 ± 18 years of age) referred for transthoracic echocardiography between 2006 and 2010, who had good-quality 2DE and 3DE images were available. Mortality data through 2016 were collected. Both 2DE and 3DE images were analyzed to measure LVEF and GLS. Additionally, 3DE-derived LV endocardial surface information was analyzed to obtain global shape indices (sphericity and conicity) and regional curvature (anterior, septal, inferior, lateral walls). Cardiovascular (CV) mortality risks related to these indices were determined using Cox regression. ResultsOf the 416 patients, 208 (50%) died, including 114 (27%) CV-related deaths over a mean follow-up period of 5 ± 3 years. Cox regression revealed that age and body surface area, all 4 LV function indices (2D EF, 3D EF, 2D GLS, 3D GLS), and regional shape indices (septal and inferior wall curvatures) were independently associated with increased risk of CV mortality. GLS was the strongest prognosticator of CV mortality, superior to EF for both 2DE and 3DE analyses, and 2D EF was the weakest among the 4 functional indices. A 1% decrease in GLS magnitude was associated with an 11.3% increase in CV mortality risk. ConclusionsGLS predicts mortality better than EF by both 3DE and 2DE analysis, whereas 3D EF is a better predictor than 2D EF. Also, LV shape indices provide additional risk assessment.

Image Segmentation and Modeling of the Pediatric Tricuspid Valve in Hypoplastic Left Heart Syndrome.

Hypoplastic left heart syndrome (HLHS) is a single-ventricle congenital heart disease that is fatal if left unpalliated. In HLHS patients, the tricuspid valve is the only functioning atrioventricular valve, and its competence is therefore critical. This work demonstrates the first automated strategy for segmentation, modeling, and morphometry of the tricuspid valve in transthoracic 3D echocardiographic (3DE) images of pediatric patients with HLHS. After initial landmark placement, the automated segmentation step uses multi-atlas label fusion and the modeling approach uses deformable modeling with medial axis representation to produce patient-specific models of the tricuspid valve that can be comprehensively and quantitatively assessed. In a group of 16 pediatric patients, valve segmentation and modeling attains an accuracy (mean boundary displacement) of 0.8 ± 0.2 mm relative to manual tracing and shows consistency in annular and leaflet measurements. In the future, such image-based tools have the potential to improve understanding and evaluation of tricuspid valve morphology in HLHS and guide strategies for patient care.

Spatiotemporal Segmentation and Modeling of the Mitral Valve in Real-Time 3D Echocardiographic Images.

Transesophageal echocardiography is the primary imaging modality for preoperative assessment of mitral valves with ischemic mitral regurgitation (IMR). While there are well known echocardiographic insights into the 3D morphology of mitral valves with IMR, such as annular dilation and leaflet tethering, less is understood about how quantification of valve dynamics can inform surgical treatment of IMR or predict short-term recurrence of the disease. As a step towards filling this knowledge gap, we present a novel framework for 4D segmentation and geometric modeling of the mitral valve in real-time 3D echocardiography (rt-3DE). The framework integrates multi-atlas label fusion and template-based medial modeling to generate quantitatively descriptive models of valve dynamics. The novelty of this work is that temporal consistency in the rt-3DE segmentations is enforced during both the segmentation and modeling stages with the use of groupwise label fusion and Kalman filtering. The algorithm is evaluated on rt-3DE data series from 10 patients: five with normal mitral valve morphology and five with severe IMR. In these 10 data series that total 207 individual 3DE images, each 3DE segmentation is validated against manual tracing and temporal consistency between segmentations is demonstrated. The ultimate goal is to generate accurate and consistent representations of valve dynamics that can both visually and quantitatively provide insight into normal and pathological valve function.

Impact of Methodologic Differences in Three-Dimensional Echocardiographic Measurements of the Aortic Annulus Compared with Computed Tomographic Angiography Before Transcatheter Aortic Valve Replacement

Three-dimensional (3D) echocardiographic (3DE) imaging is an alternative to multi-detector row computed tomography (MDCT) for aortic annular measurement before transcatheter aortic valve replacement (TAVR). A commonly used direct planimetry from a reconstructed short-axis view has not been compared with semiautomated 3DE methods. Typically accepted optimal cutoffs for percent prosthesis-area oversizing of the balloon-expandable SAPIEN or SAPIEN XT valve to native annular size are approximately 5% to 15%. The aim of this study was to compare semiautomated and direct planimetric 3DE methods for aortic annular sizing with a gold standard of MDCT to determine predictive value for paravalvular regurgitation (PVR) and balloon postdilatation. In this retrospective analysis, aortic annular cross-sectional area was measured from pre-TAVR imaging using (1) MDCT (CT_Area), (2) a 3D transesophageal echocardiographic (TEE) semiautomated method(3DE_Area_SA), and (3) a 3D TEE direct planimetric method (3DE_Area_Direct). Annular area percent oversizing was calculated. PVR after TAVR was assessed from intraoperative TEE imaging. Need for balloon postdilatation was recorded. One hundred patients who underwent TAVR with either the SAPIEN or SAPIEN XT balloon-expandable prosthesis were analyzed. Twenty-three patients hadmild or greater PVR after TAVR. CT_Area was 442±79mm2, 3DE_Area_SA was 435±81mm2, and 3DE_Area_Direct was 429±82mm2. Both 3DE_Area_SA and 3DE_Area_Direct underestimated MDCT (P<.05). All methods were highly correlative (R=0.88-0.93, P<.0001). Percent oversizing obtained by the three methods significantly predictedmild or greater PVR and need for balloon postdilatation by receiver operating characteristic analysis, with optimal cutoffs for CT_Area (9%-10%) and 3DE_Area_SA (14%) within the recommended ranges for the studied transcatheter valves and for 3DE_Area_Direct higher than the recommended range (18%-19%). Inter- and intraobserver reproducibility were lowest for 3DE_Area_Direct. Caution must be used when using 3D TEE direct planimetry of the aortic annulus, as optimal percent oversizing ranges approach the level associated with root injury, and measurements are less reproducible. Therefore, semiautomated 3DE planimetry is preferred to 3DE direct planimetry for aortic annulus sizing.

Evaluation of fetal cardiac valve anomalies by four-dimensional echocardiography with spatiotemporal image correlation (4DSTIC).

Prenatal diagnosis of cardiac valve anomalies challenged most screening sonographers. The purpose of the study was to evaluate the use of four-dimensional echocardiography with spatiotemporal image correlation (4DSTIC) in detecting normal and abnormal fetal cardiac valves. Forty-three cases of confirmed cardiac valve anomalies identified by two-dimensional echocardiography (2DE) were retrospectively reviewed in this study. Additional 121 confirmed normal fetuses were included as controls. Four-dimensional volumes were acquired from each fetus using a transverse sweep. Four-dimensional rendered images were retrieved from the volumes for each of the cardiac valves for the normal fetuses and for the intended valves for fetuses with valve malformations. The visualization rates of cardiac valves retrieved from 4D volumes in the normal fetuses ranged from 72.5% to 97.5% before 33 gestational weeks and from 46.3% to 80.5% in late pregnancy. Furthermore, 4D rendered images were successfully obtained in 38 of 43 (88.4%) fetuses with cardiac valve lesions. The 4D images and cine loops displayed the valves anatomy vividly in both normal and abnormal fetuses, including some subtle malformations which were not identified by traditional 2DE. The standardized protocol we propose herein was important in obtaining the 4D images from the volumes. The 4D modality allows a better visualization of fetal cardiac valves and should be considered a valuable addition to traditional 2DE imaging.

Modeling the Myxomatous Mitral Valve With Three-Dimensional Echocardiography

Degenerative mitral valve disease is associated with variable and complex defects in valve morphology. Three-dimensional echocardiography (3DE) has shown promise in aiding preoperative planning for patients with this disease but to date has not been as transformative as initially predicted. The clinical usefulness of 3DE has been limited by the laborious methods currently required to extract quantitative data from the images. To maximize the utility of 3DE for preoperative valve evaluation, this work describes an automated 3DE image analysis method for generating models of the mitral valve that are well suited for both qualitative and quantitative assessment. The method is unique in that it captures detailed alterations in mitral leaflet and annular morphology and produces image-derived models with locally varying leaflet thickness. The method is evaluated on midsystolic transesophageal 3DE images acquired from 22 subjects with myxomatous degeneration and from 22 subjects with normal mitral valve morphology. Relative to manual image analysis, the automated method accurately represents both normal and complex leaflet geometries with a mean boundary displacement error on the order of one image voxel. A detailed quantitative analysis of the valves is presented and reveals statistically significant differences between normal and myxomatous valves with respect to numerous aspects of annular and leaflet geometry. This work demonstrates a successful methodology for the relatively rapid quantitative description of the complex mitral valve distortions associated with myxomatous degeneration. The methodology has the potential to significantly improve surgical planning for patients with complex mitral valve disease.

Feasibility of One-Beat Real-Time Full-Volume Three-Dimensional Echocardiography for Assessing Left Ventricular Volumes and Deformation Parameters

Real-time three-dimensional echocardiographic (3DE) imaging usually requires multibeat acquisition to maintain high temporal and spatial resolution for full-volume data sets. However, this procedure generates stitch artifacts in patients with irregular heartbeats; thus, one-beat acquisition might be useful. The aim of this study was to compare the efficacy of using new-generation one-beat full-volume acquisition for measuring left ventricular (LV) mechanical parameters with that of four-beat acquisition. In protocol 1, 34 patients who had undergone both cardiac magnetic resonance and 3DE imaging on the same day were prospectively enrolled. In protocol 2, 115 patients in sinus rhythm who had undergone 3DE examinations were retrospectively enrolled. LV volume, ejection faction, and global strain were measured using one-beat and four-beat 3DE data sets. In protocol 3, 26 patients with atrial fibrillation who had acquisition of consecutive one-beat full-volume data sets were retrospectively enrolled, and it was determined whether the LV parameters in the index beat were correlated with corresponding average values obtained from multiple one-beat acquisitions. In protocol 1, the correlations between LV volumes and LV ejection fraction between cardiac magnetic resonance and 3DE imaging with one-beat acquisition were excellent (r=0.91-0.93). In protocol 2, correlations were also excellent (r=0.94-0.99), and there were no significant differences in volume rate, LV volumes, LV ejection fraction, and global strain parameters between one-beat and four-beat acquisition data sets. In protocol 3, correlations were excellent (r=0.94-0.99) between LV parameters from the index beat and corresponding average values. Three-dimensional echocardiographic full-volume data sets with one-beat acquisition not only maintained volume rate but also provided LV mechanical parameter values similar to those obtained using multibeat acquisition. Using one-beat acquisition for patients with atrial fibrillation expands its clinical applicability.

In-vivo heterogeneous functional and residual strains in human aortic valve leaflets

Residual and physiological functional strains in soft tissues are known to play an important role in modulating organ stress distributions. Yet, no known comprehensive information on residual strains exist, or non-invasive techniques to quantify in-vivo deformations for the aortic valve (AV) leaflets. Herein we present a completely non-invasive approach for determining heterogeneous strains – both functional and residual – in semilunar valves and apply it to normal human AV leaflets. Transesophageal 3D echocardiographic (3DE) images of the AV were acquired from open-heart transplant patients, with each AV leaflet excised after heart explant and then imaged in a flattened configuration ex-vivo. Using an established spline parameterization of both 3DE segmentations and digitized ex-vivo images (Aggarwal et al., 2014), surface strains were calculated for deformation between the ex-vivo and three in-vivo configurations: fully open, just-coapted, and fully-loaded. Results indicated that leaflet area increased by an average of 20% from the ex-vivo to in-vivo open states, with a highly heterogeneous strain field. The increase in area from open to just-coapted state was the highest at an average of 25%, while that from just-coapted to fully-loaded remained almost unaltered. Going from the ex-vivo to in-vivo mid-systole configurations, the leaflet area near the basal attachment shrank slightly, whereas the free edge expanded by ~10%. This was accompanied by a 10° −20° shear along the circumferential-radial direction. Moreover, the principal stretches aligned approximately with the circumferential and radial directions for all cases, with the highest stretch being along the radial direction. Collectively, these results indicated that even though the AV did not support any measurable pressure gradient in the just-coapted state, the leaflets were significantly pre-strained with respect to the excised state. Furthermore, the collagen fibers of the leaflet were almost fully recruited in the just-coapted state, making the leaflet very stiff with marginal deformation under full pressure. Lastly, the deformation was always higher in the radial direction and lower along the circumferential one, the latter direction made stiffer by the preferential alignment of collagen fibers. These results provide significant insight into the distribution of residual strains and the in-vivo strains encountered during valve opening and closing in AV leaflets, and will form an important component of the tool that can evaluate valve׳s functional properties in a non-invasive manner.

Abstract 14692: Evaluation of Subaortic Right Ventricular Function in ccTGA: How Do Echocardiography Parameters Compare to CMR?

Background: Subaortic right ventricular (RV) functional assessment in patients with congenitally corrected transposition of the great arteries (ccTGA) is important for both long-term outcome and as an indication for tricuspid valve replacement. Cardiac magnetic resonance (CMR) imaging is considered the reference standard for assessment of subaortic RV systolic function. However, two-dimensional echocardiography (2DE) remains the most frequently used imaging modality in clinical practice. Objective: To compare 2DE and CMR parameters of RV function in patients with ccTGA. Methods: We identified adults (≥18) with the diagnosis of ccTGA who underwent consecutive CMR and 2DE imaging within 6 months between 2005 and 2015. Patients with tricuspid valve replacement or pacemaker were excluded. 2DE images were reviewed and the following RV parameters re-measured by a single observer: fractional area shortening (FAC), tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (Ts’), the rate of systolic RV pressure increase (dp/dt) and myocardial acceleration during isovolumic contraction (IVA). RVEF as measured by CMR was recorded. Results: There were 82 matched 2DE and CMR studies in 42 ccTGA patients (50% male). Median age at 2DE was 33.1 years (IQR = 22.7- 48.2 year). Pearson correlation analysis demonstrated a weak correlation between FAC and RVEF (r 2 =0.143, p=0.0005). Other 2DE parameters failed to show any correlation with RVEF (Figure 1). Conclusion: In general, 2DE parameters for the assessment of subaortic RV systolic function correlate poorly with CMR measured RVEF in patients with ccTGA. This is important information for selection and interpretation of various modalities in the long-term follow-up of this patient population.

Medially constrained deformable modeling for segmentation of branching medial structures: Application to aortic valve segmentation and morphometry.

Deformable modeling with medial axis representation is a useful means of segmenting and parametrically describing the shape of anatomical structures in medical images. Continuous medial representation (cm-rep) is a "skeleton-first" approach to deformable medial modeling that explicitly parameterizes an object's medial axis and derives the object's boundary algorithmically. Although cm-rep has effectively been used to segment and model a number of anatomical structures with non-branching medial topologies, the framework is challenging to apply to objects with branching medial geometries since branch curves in the medial axis are difficult to parameterize. In this work, we demonstrate the first clinical application of a new "boundary-first" deformable medial modeling paradigm, wherein an object's boundary is explicitly described and constraints are imposed on boundary geometry to preserve the branching configuration of the medial axis during model deformation. This "boundary-first" framework is leveraged to segment and morphologically analyze the aortic valve apparatus in 3D echocardiographic images. Relative to manual tracing, segmentation with deformable medial modeling achieves a mean boundary error of 0.41 ± 0.10 mm (approximately one voxel) in 22 3DE images of normal aortic valves at systole. Deformable medial modeling is additionally demonstrated on pathological cases, including aortic stenosis, Marfan syndrome, and bicuspid aortic valve disease. This study demonstrates a promising approach for quantitative 3DE analysis of aortic valve morphology.

Proteomic and functional profiles of a follicle-stimulating hormone positive human nonfunctional pituitary adenoma.

Nonfunctional pituitary adenoma (NFPA) is highly heterogeneous with different hormone-expressed subtypes in NFPA tissues including follicle-stimulating hormone (FSH) positive, luteinizing hormone-positive, FSH/luteinizing hormone-positive, and negative types. To analyze in-depth the variations in the proteomes among different NFPA subtypes for our long-term goal to clarify molecular mechanisms of NFPA and to detect tumor biomarker for personalized medicine practice, a reference map of proteome of a human FSH-expressed NFPA tissue was described here. 2DE and PDQuest image analysis were used to array each protein. MALDI-TOF PMF and human Swiss-Prot databases with MASCOT search were used to identify each protein. A good 2DE pattern with high level of between-gel reproducibility was attained with an average positional deviation 1.98 ± 0.75 mm in the IEF direction and 1.62 ± 0.68 mm in the SDS-PAGE direction. Approximately 1200 protein spots were 2DE-detected and 192 redundant proteins that were contained in 141 protein spots were PMF-identified, representing 107 nonredundant proteins. Those proteins were located in cytoplasm, nucleus, plasma membrane, extracellular space, and so on, and those functioned in transmembrane receptor, ion channel, transcription/translation regulator, transporter, enzyme, phosphatase, kinase, and so on. Several important pathway networks were characterized from those identified proteins with DAVID and Ingenuity Pathway Analysis systems, including gluconeogenesis and glycolysis, mitochondrial dysfunction, oxidative stress, cell-cycle alteration, MAPKsignaling system, immune response, TP53-signaling, VEGF-signaling, and inflammation signaling pathways. Those resulting data contribute to a functional profile of the proteome of a human FSH-positive NFPA tissue, and will serve as a reference for the heterogeneity analysis of NFPA proteomes.

Adaptive image inversion of contrast 3D echocardiography for enabling automated analysis

IntroductionContrast 3D echocardiography (C3DE) is commonly used to enhance the visual quality of ultrasound images in comparison with non-contrast 3D echocardiography (3DE). Although the image quality in C3DE is perceived to be improved for visual analysis, however it actually deteriorates for the purpose of automatic or semi-automatic analysis due to higher speckle noise and intensity inhomogeneity. Therefore, the LV endocardial feature extraction and segmentation from the C3DE images remains a challenging problem. MethodsTo address this challenge, this work proposes an adaptive pre-processing method to invert the appearance of C3DE image. The image inversion is based on an image intensity threshold value which is automatically estimated through image histogram analysis. ResultsIn the inverted appearance, the LV cavity appears dark while the myocardium appears bright thus making it similar in appearance to a 3DE image. Moreover, the resulting inverted image has high contrast and low noise appearance, yielding strong LV endocardium boundary and facilitating feature extraction for segmentation. ConclusionsOur results demonstrate that the inverse appearance of contrast image enables the subsequent LV segmentation.

Subclinical hyperthyroidism impacts left ventricular deformation: 2D and 3D echocardiographic study

Background. We sought to investigate left ventricular (LV) function and mechanics assessed by three-dimensional echocardiography (3DE) and speckle tracking in patients with subclinical hyperthyroidism (SCH). Methods. We included 35 untreated women with SCH and 35 healthy control women matched by age. All participants underwent laboratory analyses which included thyroid hormone levels, and complete 2DE and 3DE examination. Results. 2DE LV longitudinal and circumferential strain was significantly decreased in the SCH subjects. 2DE LV systolic and early diastolic strain rates in longitudinal and circumferential directions were reduced, whereas late diastolic strain rates were increased in SCH individuals. 3DE LV end-diastolic volume and cardiac output were significantly elevated in the SCH patients. 3DE LV deformation in all three directions, as well as 3DE area strain, were significantly lower in the SCH group. Serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels correlated with 2DE LV mass index, 2DE longitudinal strain, and 3DE LV area strain in the whole study population. Conclusion. LV deformation evaluated by 3DE and speckle tracking imaging are significantly impaired in SCH subjects. TSH and FT4 levels correlate with 2DE and 3DE LV structure and mechanics.

Three-dimensional echocardiography of congenital abnormalities of the left atrioventricular valve.

Congenital abnormalities of the left atrioventricular (AV) valve are a significant diagnostic challenge. Traditionally, reliance has been placed on two-dimensional echocardiographic (2DE) imaging to guide recognition of the specific morphological features. Real-time 3DE can provide unique views of the left AV valve with the potential to improve understanding of valve morphology and function to facilitate surgical planning. This review illustrates the features of congenital abnormalities of the left AV valve assessed by 3DE. The similarities and differences in morphology between different lesions are described, both with respect to the valve itself and supporting chordal apparatus. The potential advantages as well as limitations of this technique in clinical practice are outlined.

Right Heart Mechanics in Untreated Normotensive Patients with Prediabetes and Type 2 Diabetes Mellitus: A Two- and Three-Dimensional Echocardiographic Study

The aim of this study was to determine right ventricular (RV) and right atrial (RA) deformation assessed by two-dimensional echocardiographic and three-dimensional echocardiographic (3DE) imaging in patients with prediabetes and type 2 diabetes mellitus. This cross-sectional study included 47 untreated normotensive subjects with prediabetes, 57 recently diagnosed normotensive patients with diabetes, and 54 healthy controls of similar sex and age distributions. All subjects underwent laboratory analyses and complete two-dimensional echocardiographic and 3DE examinations. Three-dimensional echocardiographic RV end-diastolic volume index gradually decreased from controls across patients with diabetes to those with diabetes (69±10 vs 63±8 vs 58±8mL/m(2), P<.001), whereas 3DE RV end-systolic volume index was higher in controls compared with patients with diabetes and those with diabetes (25±4 vs 23±4 vs 22±4mL/m(2), P<.001). However, there was no difference in 3DE RV ejection fraction among the three groups (63±4% vs 62±4% vs 61±5%, P=.063). RV and RA global strain and systolic and early diastolic strain rates were decreased in patients with prediabetes and in those with diabetes compared with controls, whereas RV and RA late diastolic strain rates were increased in these patients. Multivariate regression analysis showed that RV global strain was associated with glycated hemoglobin, independent of left ventricular parameters. RV and RA myocardial deformation and function obtained by 3DE and two-dimensional echocardiographic strain, even in normal ranges, were decreased in patients with prediabetes and in those with diabetes compared with controls. The long-term parameter of glucose control was correlated with the right heart mechanics.

Segmentation of the Aortic Valve Apparatus in 3D Echocardiographic Images: Deformable Modeling of a Branching Medial Structure.

3D echocardiographic (3DE) imaging is a useful tool for assessing the complex geometry of the aortic valve apparatus. Segmentation of this structure in 3DE images is a challenging task that benefits from shape-guided deformable modeling methods, which enable inter-subject statistical shape comparison. Prior work demonstrates the efficacy of using continuous medial representation (cm-rep) as a shape descriptor for valve leaflets. However, its application to the entire aortic valve apparatus is limited since the structure has a branching medial geometry that cannot be explicitly parameterized in the original cm-rep framework. In this work, we show that the aortic valve apparatus can be accurately segmented using a new branching medial modeling paradigm. The segmentation method achieves a mean boundary displacement of 0.6 ± 0.1 mm (approximately one voxel) relative to manual segmentation on 11 3DE images of normal open aortic valves. This study demonstrates a promising approach for quantitative 3DE analysis of aortic valve morphology.

Proteolytic changes of myofibrillar proteins in Podolian meat during aging: focusing on tenderness.

The aim of this study was to understand the relationship between changes in postmortem degradation of myofibrillar proteins and tenderness development in 3 different muscles from 10 Podolian young bulls aged 1, 7, 14, and 21 d. Psoas major (PM), longissimus dorsi (LD), and semitendinosus muscle () were removed from each half carcass 24 h postmortem. Meat chemical composition, Warner-Bratzler shear force (WBSF), myofibril fragmentation index (MFI), total collagen content, and changes in myofibrillar proteins were estimated in triplicate at each aging time. A significant muscle effect was found on meat chemical composition. Semitendinosus muscle showed the lowest intramuscular fat percentage ( < 0.01) and the highest total collagen content ( < 0.01) with respect to LD and PM. Warner-Bratzler shear force decreased during aging in all muscles ( < 0.001), and semitendinosus was the toughest muscle whereas PM was the most tender ( < 0.001). Myofibril fragmentation index significantly increased ( < 0.001) in LD and PM meat throughout aging time whereas in semitendinosus it increased from 14 d of aging. Proteolysis was investigated by SDS-PAGE, western blotting, and 2-dimensional electrophoresis. Throughout postmortem aging, some structural proteins changed in intensity in all muscles analyzed. The blotting profile highlighted that desmin and troponin-T (TnT) bands were affected by both muscle and aging effects. Desmin degradation was more intense and faster in LD muscle than in semitendinosus and PM muscles. A progressive increase of the degraded isoforms of TnT (33 and 30 kDa polypeptides) was found during aging in LD, while, in PM these bands appeared earlier showing a greater intensity from 1 d. During aging, 2-dimensional gel electrophoresis (2DE) image analyses results showed a significant increase of the total number of spots reaching the highest value in the LD muscle at 21 d of aging ( < 0.01). Proteins separation also revealed differences in the spot number and expression patterns of myosin light chain (MLC) isoforms among muscles. A principal components analysis applied to meat chemical composition, tenderness, and myofibrillar proteins accounted for approximately 96.09% of total variance. Data highlight that aging affects the meat tenderness and proteolysis with different intensities in each muscle. These results provide knowledge about the tenderness mechanism in different muscles from a rustic breed and could be useful for the development of muscle specific strategies for improving the quality and value in different commercial cuts.

Comparative proteomic analysis of pollen of Trifolium pratense, T. alexandrinum and T. repens

Clovers are widely distributed, but their pollen proteome still has not been completely elucidated. In this study we performed a comprehensive comparative proteomic analysis of red, berseem and white clover pollen. Handcollected pollen of different clover species were used for total protein extraction. Proteins isolated from red clover cvs. ‘Kirsiniai’ and ‘Vyciai’, berseem clover cv. ‘Faraon’ and white clover cv. ‘Medūnai’, populations Nos. 2295 4n and 2196 4n, were subjected to fractionation by one-dimensional electrophoresis. Some quantitatively different protein groups were characterized in protein maps typical of analyzed clover pollens. For the detailed proteomic analysis we chose pollen of red clover cv. ‘Vyciai’, berseem clover cv. ‘Faraon’ and white clover cv. ‘Medūnai’. Proteins isolated from the pollen were fractionated by two-dimensional electrophoresis (2DE) and stained for visualisation by using Coomassie blue. Each of the 2DE images indicated over 200 protein spots. Computational methods developed by us were applied for characterization and comparison of proteins isolated from the pollen of the three clover species. The computational methods enabled the evaluation of protein expression variations in red, berseem and white clover pollen proteome maps. By using computer-assisted image analysis of the gels, the expression levels of the proteins were evaluated and their molecular weight and isoelectric point were precisely characterized. We detected over 30 protein spots whose quantitative levels were most divergent in investigated clover pollen proteome map. They were analyzed by mass spectrometry and identified. The fold changes of identified proteins representing red clover cv. ‘Vyciai’, berseem clover cv. ‘Faraon’ and white clover cv. ‘Medūnai’ were calculated using computer-assisted methods.

Accuracy and Reproducibility of Right Ventricular Quantification in Patients with Pressure and Volume Overload Using Single-Beat Three-Dimensional Echocardiography

BackgroundThe right ventricle is a complex structure that is challenging to quantify by two-dimensional (2D) echocardiography. Unlike disk summation three-dimensional (3D) echocardiography (3DE), single-beat 3DE can acquire large volumes at high volume rates in one cardiac cycle, avoiding stitching artifacts or long breath-holds. The aim of this study was to assess the accuracy and test-retest reproducibility of single-beat 3DE for quantifying right ventricular (RV) volumes in adult populations of acquired RV pressure or volume overload, namely, pulmonary hypertension (PH) and carcinoid heart disease, respectively. Three-dimensional and 2D echocardiographic indices were also compared for identifying RV dysfunction in PH.MethodsA prospective cross-sectional study was performed in 100 individuals who underwent 2D echocardiography, 3DE, and cardiac magnetic resonance imaging: 49 patients with PH, 20 with carcinoid heart disease, 11 with metastatic carcinoid tumors without cardiac involvement, and 20 healthy volunteers. Two operators performed test-retest acquisition and postprocessing for inter- and intraobserver reproducibility in 20 subjects.Results:RV single-beat 3DE was attainable in 96% of cases, with mean volume rates of 32 to 45 volumes/sec. Bland-Altman analysis of all subjects (presented as mean bias ± 95% limits of agreement) revealed good agreement for end-diastolic volume (−2.3 ± 27.4 mL) and end-systolic volume (5.2 ± 19.0 mL) measured by 3DE and cardiac magnetic resonance imaging, with a tendency to underestimate stroke volume (−7.5 ± 23.6 mL) and ejection fraction (−4.6 ± 13.8%) by 3DE. Subgroup analysis demonstrated a greater bias for volumetric underestimation, particularly in healthy volunteers (end-diastolic volume, −11.9 ± 18.0 mL; stroke volume, −11.2 ± 20.2 mL). Receiver operating characteristic curve analysis showed that 3DE-derived ejection fraction was significantly superior to 2D echocardiographic parameters for identifying RV dysfunction in PH (sensitivity, 94%; specificity, 88%; area under the curve, 0.95; P = .031). There was significant interobserver test-retest bias for RV volume underestimation (end-diastolic volume, −12.5 ± 28.1 mL; stroke volume, −10.6 ± 23.2 mL).ConclusionsSingle-beat 3DE is feasible and clinically applicable for volumetric quantification in acquired RV pressure or volume overload. It has improved limits of agreement compared with previous disk summation 3D echocardiographic studies and has incremental value over standard 2D echocardiographic measures for identifying RV dysfunction. Despite the ability to obtain and postprocess a full-volume 3D echocardiographic RV data set, the quality of the raw data did influence the accuracy of the data obtained. The technique performs better with dilated rather than nondilated RV cavities, with a learning curve that might affect the test-retest reproducibility for serial RV studies.

2D electrophoresis image segmentation within a pixel-based framework

Two-dimensional electrophoresis (2DE) is a traditional proteomics tool still used extensively to study differences in complex protein expression profiles between related biological samples. The methods can resolve thousands of intact proteins on a gel. However, the resulting image pattern is complex.Traditionally, each individual 2DE image, representing one replicate of one biological sample, is first segmented into its many different spots and the volume is quantified for each spot in each gel image; thereafter lists of protein spot volumes from different samples are collected for statistical analysis. This segmentation-before-analysis approach is known to cause considerable segmentation problems due to weak or overlapping protein spots, which in turn causes, for instance, missing values and other misrepresentations in the resulting spot volume table and hence problems in the statistical analysis. The pixel-based approach was introduced to solve some of the challenges inherited in the analysis of 2DE images, in particular, caused by early spot detection.The current paper follows a complete pixel-based approach from aligning to a resulting spot volume table, with several novel steps along the workflow. The workflow encompasses image pre-processing, pixel-based analyses, segmentation where the experimental design is utilised, and final data table reporting. Our approach employs optical flow estimation for alignment, and technical variation is removed prior to the statistical validation. The statistical data analyses are based on ANOVA adjusted by rotation testing and on resampled PLS regression at pixel level. A novel approach for segmentation is performed based on the statistical output performed on pixel level (regression coefficients and their p-values or t-values), and refolded to image representation (meta image). A double threshold is used to distinguish random false positive pixels from structured information of protein spots. Finally, the end user is presented a list of protein spots of interest at spot volume level rather than pixel level where the spot detection procedure has taken into account the relevance in light of the experimental design.