Trabecular Bone Microarchitectural Outcomes of the Mandible and Tibia or Lumbar Vertebrae are Correlated in SHAM but not the OVX Rat Model of Postmenopausal Osteoporosis
Notice bibliographique
Résumé
In postmenopausal (PM) women, tooth loss and/or low bone mineral density (BMD) of the jaw is correlated with low BMD (i.e. osteoporosis) at other skeletal sites. Moreover, tooth loss, in general, makes it more difficult to consume healthy foods that often require more forceful mastication. Thus, there is a cyclic relationship among oral health, consumption of a nutritious diet, and the risk of osteoporosis. The ovariectomized (OVX) rat model is the FDA‐approved model of PM osteoporosis, and is commonly used to investigate how diet can attenuate the development of osteoporosis. OVX causes a skeletal‐site specific response, such that loss of bone quantity and quality in the long bones is greater than in the lumbar vertebrae (LV) and mandible. However, few studies have evaluated the correlation of trabecular microarchitectural outcomes, as measured by micro‐computed tomography (mCT), between mandible and tibia or LV to determine the fitness of the mandible as a predictor of overall bone health. The objective of this study was to determine if trabecular microarchitectural outcomes of the mandible and the tibia or LV are correlated in this widely used pre‐clinical model of PM osteoporosis, to understand how closely this model mimics changes observed in PM women. Three‐month old Sprague‐Dawley rats were randomized to SHAM (n=47) or OVX (n=49) and were maintained on an ad libitum diet until 6 months of age. Ex vivo mCT imaging of the mandible (alveolar bone) and LV, and in vivo mCT imaging of proximal tibia was conducted. Trabecular microarchitectural measurements, including percent bone volume (BV/TV), trabecular thickness (Tb.Th.), trabecular number (Tb.N.), trabecular separation (Tb.Sp.), and degree of anisotropy were quantified at each bone site. Correlation between these outcomes (mandible vs. tibia; mandible vs. LV) within SHAM or OVX rats was conducted using a Pearson's correlation test. Within rats randomized to SHAM, positive correlations exist between all bone sites for the outcomes BV/TV (p<0.001), Tb.N. (p<0.001), and Tb.Sp. (p<0.05). A negative correlation was observed between the mandible and LV for the outcome Tb.Th. (p<0.05). Within rats randomized to OVX, the sole positive correlation was between the mandible and tibia for Tb.Sp. (p<0.05). As expected, when the percent change between SHAM and OVX groups was assessed at 6 months of age, the most dramatic effect was seen at the tibia (−71% BV/TV), followed by the LV (−36% BV/TV) and mandible (−8% BV/TV). These results demonstrate that OVX has skeletal‐site specific effects on trabecular microarchitecture, and these relative responses may at least partially explain the lack of correlations among mandible and tibia or LV after OVX. In conclusion, positive correlations between BMD and trabecular bone microarchitecture of mandible and tibia or LV are observed in SHAM rats but not after OVX. Therefore, the alveolar bone of the mandible of OVX rats does not closely mimic the bone loss that occurs in PM women and does not reliably predict changes at other skeletal sites in the time frame studied. Support or Funding Information The authors acknowledge funding provided by the Natural Sciences and Engineering Research Council of Canada and the Canada Research Chairs program as well as infrastructure support from the Canada Foundation for Innovation.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».