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Abstract 976: Hyperpolarized Mitochondria in Right Ventricular Hypertrophy: a Target for Ventricular-Specific Therapies

2007· article· en· W967516698 on OpenAlexaff
Jayan Nagendran, Vikram Gurtu, Jason R.B. Dyck, David B. Ross, Ivan M. Rebeyka, Evangelos D. Michelakis

Bibliographic record

VenueCirculation · 2007
Typearticle
Languageen
FieldMedicine
TopicPulmonary Hypertension Research and Treatments
Canadian institutionsUniversity of Alberta
Fundersnot available
KeywordsNFATMedicineMuscle hypertrophyInternal medicinePhenylephrinePulmonary hypertensionVentricleMitochondrionRight ventricular hypertrophyEndocrinologyPressure overloadAfterloadCardiologyCardiac hypertrophyCalcineurinBlood pressureCell biologyBiologyTransplantation

Abstract

fetched live from OpenAlex

Objectives : The right ventricle (RV) fails quickly after increases in its afterload (pulmonary hypertension) compared to the LV (systemic hypertension). We hypothesized that the suboptimal performance of the hypertrophied RV (RVH) is caused by metabolic adaptation during hypertrophy. Mitochondria regulate metabolism, and mitochondrial membrane potential (ΔΨm) is a surrogate for mitochondrial function. Methods/Results : We measured ΔΨm in normal and hypertrophied myocardial specimens from 11 patients and in a rat model of RVH, using Tetramethylrhodamine methyl ester, a positively-charged dye that selectively localizes within the negatively charged mitochondria. ΔΨm was significantly higher in the normal LV compared to normal RV, and was the highest in RVH, both at the myocardium and isolated cardiomyocyte levels (p<0.01 for both). The increase in ΔΨm was recapitulated in an in vitro model of hypertrophy, where isolated neonatal cardiomyocytes were exposed to phenylephrine. This increase in ΔΨm was reversed by both a direct inhibitor of NFAT (Nuclear-Factor-of-Activated-T-lymphocytes, a transcription factor that regulates cardiac metabolism in development and hypertrophy) and Dichloroacetate (DCA, a metabolic modulator that has been shown to depolarize mitochondria and inhibit NFAT, reversing the phenotype of disease in both cancer and pulmonary hypertension) (p<0.01 for both). In ex-vivo Langendorff perfusions DCA acutely increased RV inotropy in rats with RVH (p<0.01) but not normal RVs, suggesting that the increased ΔΨm in RVH might be associated with its suboptimal performance in patients with pulmonary hypertension. Conclusions : The significant differences in ΔΨm between RV, LV, and RVH, can be targeted metabolically by DCA to improve contractility in RVH and provide a framework for development of novel RV-specific therapies.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.009
Threshold uncertainty score0.029

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0090.002

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.

Opus teacher head0.024
GPT teacher head0.282
Teacher spread0.257 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

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".

Quick stats

Citations0
Published2007
Admission routes1
Has abstractyes

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