Speaker abstracts
Notice bibliographique
Résumé
The age of stored erythrocytes has been implicated as a potential etiology of several adverse clinical outcomes: immunomodulation, transfusion-associated lung injury, multiple organ failure; and lack of efficacy: failure to provide adequate tissue oxygenation.The latter is based on two physiological changes occurring with erythrocyte storage.Erythrocyte concentrations of 2,3-diphosphoglycerate (2,3-DPG) decrease with duration of storage, and reach depleted concentrations of 1 lmol/g hemoglobin or less at 21 days of storage.1-3 2,3-DPG is an important determinant of the affinity of hemoglobin for oxygen, with affinity increasing (P50 decreasing) as 2,3-DPG decreases 4,5 (and thus, as erythrocyte storage age increases).This has led some to postulate that transfused stored erythrocytes bind oxygen too tightly to allow for oxygen release at physiologic conditions 6 until 2,3-DPG increases, some hours after transfusion.2,3,[6][7][8] The second potential biophysical basis for the putative lack of immediate efficacy of transfused stored erythrocytes is that erythrocytic concentrations of adenosine triphosphate (ATP) decrease with storage duration.Decreased erythrocyte ATP concentrations have been associated with decreased erythrocyte deformability and in vivo survival secondary to impaired ability of erythrocytes to pass the microcirculation.9,10 However, this hypothesis has been questioned by more recent data using laser technology.11,12 Other studies in humans either have not been prospective and randomized, or have not tested humans using an appropriately sensitive measure when the subjects were in an oxygendependent state.We utilized our model of severe acute anemia, 13 in which cognitive function 14,15 and central neurophysiologic function as assessed by P300 16 are oxygen-delivery dependent, to test this hypothesis.With institutional approval and subjectsÕ informed consent, we studied nine volunteers (sample size determined by a priori power analyses) made acutely isovolemic anemic to a hemoglobin concentration of 50 g/L on two separate days, separated by 7 days.Cognitive function was tested with a computerized digit-symbol substitution test (DSST) each day before induction of anemia, at hemoglobin concentrations of 7 g/dL and 5 g/dL, and after transfusion of autologous erythrocytes, either stored for 3 h (ÔfreshÕ) or stored at usual blood bank conditions for 3 weeks, in sufficient quantity to increase the hemoglobin concentration to 7 g/dL.The type of erythrocytes transfused on each volunteer's first experimental day was randomly allocated; the alternate type of erythrocytes was transfused on the second experimental day.The subject and the person administering and evaluating the DSST were blinded as to type of erythrocyte transfused.Three weeks of storage reduced 2,3-DPG concentration from a normal value of 11.9 (10.4-13.4)lmol/g hemoglobin [mean (95% confidence interval)] to 1.1 lmol/g (0.7-1.5) (P < 0.001); 3 h of storage did not significantly change 2,3-DPG concentration.The P50 of the erythrocytes stored for 3 weeks was reduced from 27.4 mmHg (26.7-28.1 mmHg) to 15.0 (14.6-15.4)mmHg, and differed significantly (P < 0.001) from the P50 of the transfused erythrocytes stored for 3 h: 25.0 (24.5-25.5)mmHg.The DSST did not differ on the two experimental days before induction of anemia.The degree of anemia induced did not differ between the two experimental days (P = 0.69).Acute isovolemic anemia impaired (slowed response) (P < 0.001) the DSST equivalently on the two
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 | 0,001 | 0,005 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,004 | 0,002 |
| Science ouverte | 0,001 | 0,002 |
| Intégrité de la recherche | 0,002 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,859 | 0,653 |
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; l’étiquette directe de Gemma et le classifieur distillé Codex s’accordent sur ce qui est montré ici.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».