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Record W7006689777

Vascular abnormalities of cerebral arteries and penetrating arterioles during hypertension and heart failure

2020· dissertation· en· W7006689777 on OpenAlexfundno aff

Bibliographic record

VenueMspace (University of Manitoba) · 2020
Typedissertation
Languageen
FieldMedicine
TopicSirtuins and Resveratrol in Medicine
Canadian institutionsnot available
FundersManitoba Health Research Council
KeywordsBlood pressureHeart failureMuscle hypertrophyLumen (anatomy)Blood flowCirculatory systemBlood vesselCerebral circulation
DOInot available

Abstract

fetched live from OpenAlex

Hypertension increases resistance to blood flow and compromises the vasculature. Chronically elevated blood pressure is antecedent to heart failure and both are associated with the development of cognitive decline and dementia. Thus, we sought to examine the cerebrovascular effects of hypertension alone and with predisposition for heart failure. Using pressurized cerebral vessels isolated from animals with genetic hypertension, we investigated structural, mechanical and functional properties by pressure myography. Structural and mechanical parameters were calculated using media and lumen dimensions measured at constant or incremental intraluminal pressures, respectively. Middle cerebral arteries (MCA) from spontaneously hypertensive heart failure (SHHF) rats underwent a combination of growth and remodeling, exhibited greater wall component stiffness and were less compliant. Studies suggest resveratrol may be beneficial for the treatment of hypertension. Therefore, we investigated the effects of resveratrol and two structural analogs on abnormal MCA. Vascular hypertrophy and wall component stiffness improved with oral doses (2.5 mg/kg/d) of resveratrol, pterostilbene and gnetol, albeit in the absence of blood pressure lowering. This indicates these stilbenoids act directly on the vascular wall. Findings in MCA led to further examination of downstream penetrating arterioles that regulate cerebral perfusion. SHHF penetrating arterioles exhibited eutrophic remodeling, increased stiffness and reduced compliance. Although eutrophic remodeling was similarly observed in spontaneously hypertensive rats (SHR), penetrating arterioles were less stiff and more compliant. Transmission electron microscopy revealed increased collagen deposition in arterioles from SHHF rats consistent with reduced compliance. Whereas, SHR arterioles had unchanged collagen/elastin ratio. Functional responses were evaluated using pharmacological agents that were bath applied to penetrating arterioles in increasing concentrations. Relaxation to glutamate/D-serine was reduced in SHHF rats but not in SHR. In contrast, acetylcholine-mediated relaxation was potentiated in SHR but maintained in SHHF rats. Interestingly, endothelium-independent relaxation to nitric oxide donor, sodium nitroprusside, resulted in constriction in both hypertensive strains. These findings suggest penetrating arterioles undergo some adaptations in hypertension, which are absent when there is a propensity for developing heart failure. Altogether, this is the first to identify and characterize the cerebrovascular abnormalities in MCA and penetrating arterioles in models of hypertension alone and with risk for heart failure.

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: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.001
Threshold uncertainty score0.002

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.009
GPT teacher head0.190
Teacher spread0.181 · 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 designObservational
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
Published2020
Admission routes1
Has abstractyes

Explore more

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