Speckle tracking analysis of the left ventricular anterior wall shows significantly decreased relative radial strain patterns in dystrophin deficient mice after 9 months of age
Bibliographic record
Abstract
BACKGROUND: Duchenne muscular dystrophy (DMD) is an inherited X-linked disorder with an incidence of 1 in 3,500 male births. Early treatment of DMD cardiomyopathy is under investigation and echocardiographic analysis of strain patterns may provide measures to better quantify early treatment outcomes. METHODS: We compared cardiac function in 3, 9 and 12 month old dystrophin deficient mdx mice to wild type (C57BL10/J) using in vivo high frequency echocardiography (Vevo 770, VisualSonics, Inc., Toronto, CA) and 2D speckle tracking [Velocity Vector Imaging (VVI), Siemens Medical Solutions, Inc., Malvern, PA]. Mice were anesthetized with 1-2% inhaled isoflurane and images were obtained using a 30 MHz transducer in modified parasternal long and short axis views obtained at the level of the papillary muscles. Myocardial motion was analyzed using VVI in single-beat reconstructed images. RESULTS: M-mode imaging showed significantly decreased shortening fraction in mdx mice compared to wild type at 12 months of age (SF% 26.6±3 vs. 32.2±2; p=0.002). Mdx mice showed significantly increased cardiac fibrosis at 12 months of age compared to controls (p<0.0001). Speckle tracking analysis of the left anterior mid ventricular wall segment showed significantly decreased relative radial strain in mdx mice at 9 and 12 months (4.5±1.3% vs. 8.4±0.7%; p=0.001). There were no significant differences in circumferential or longitudinal strain. CONCLUSION: Mdx mice show significantly decreased LV anterior mid wall radial strain with mild cardiomyopathy after 9 months of age compared to wild type. Speckle tracking analysis may provide novel outcome measures for preclinical cardiac drug treatment studies in DMD.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".