The science of stem cells: some implications for law and policy.
Notice bibliographique
Résumé
Introduction There are few areas of modem biomedical research that have aroused as much controversy as stem Scientists, physicians, patients and patient advocacy groups tend to emphasize the potential therapeutic benefits. Others argue that the potential benefits of stem cells have been exaggerated. Entrepreneurs, and research scientists -- who are sometimes one and the same -- envision vast medical and financial profits from stem cell therapy. Religious leaders pronounce judgments based strictly on faith and their understanding of when life begins. Those in positions of political power are eager to remain in power and seek a position wherein the fewest number of people are offended by a given policy choice. At first sight, the development of stem cells does not seem to be very different from other scientific developments, except that in the case of stem cells, an understanding of the scientific facts of stem cell technology per se, the embryology and the associated terminology is critically important to making ethically sound policy judgments. The facts, definitions and terminology are confusing and are liable to misuse by those who seek to further a particular position. It is our position that a coherent discourse needs to be initiated so that regulation in this area, if undertaken, is rational, consistent and informed by a clear understanding of the science and the terminology. In this paper we provide a concise overview of the important scientific facts related to embryology and embryonic stem cells and highlight some recent scientific developments that are salient for the purpose of regulatory development in this field. Why such Enthusiasm over Stem Cells? Stem cells are exciting to physicians, scientists and patients because of their potential to develop into many different cell types, tissues and perhaps even organs that can possibly be used to treat large numbers of patients with a variety of diseases. (1) To scientists, stem cells offer a new way of exploring fundamental questions of biology, especially those pertaining to embryonic development. (2) In the living body, stem cells are believed to exist in small numbers in most organs including the liver, blood and brain. Stem cells have two crucial capabilities: (1) they divide repeatedly into stem cells of their own type; and (2) with appropriate stimuli they can develop or differentiate either into one particular tissue, into a small number of tissues or, as m the case of pluripotent embryonic stem cells, into potentially all types of tissue. (3) Embryonic Stem Cells For years, pluripotent embryonic stem cells have been viewed as the holy grail for many scientists, particularly developmental biologists. Murine embryonic stem cells were discovered about 20 years ago, but despite intense research, human embryonic stem cells have eluded scientists until recently. In 1998, almost simultaneously, two research groups in the United States (4) discovered how to purify embryonic stem cells and maintain them in culture in the laboratory. Thomson and his colleagues purified cells from spare embryos from IVF clinics. (5) Gearheart and his colleagues purified cells, functionally the same as Thomson's cells, from the gonadal ridges of early abortuses. (6) The type of cells described by Gearheart and his colleagues have been confusingly called germ cells. Embryonic stem cells (ESCs), as they feature in much of the current debate, are those cells derived from embryos at the blastocyst stage, which is approximately five to seven days after fertilization. (7) At this stage, within the blastocyst, there is a small fluid collection (cyst) in the embryo and at one pole of the cyst a specialized clump of cells known as the inner cell mass. It is from this inner cell mass that ESCs can be obtained. (8) Several research teams have now been able to establish cell lines in the laboratory that continue to divide into succeeding generations of daughter cells that are identical to the original ESCs. …
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 | 0,016 | 0,020 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,003 | 0,003 |
| Études des sciences et des technologies | 0,006 | 0,036 |
| Communication savante | 0,014 | 0,018 |
| Science ouverte | 0,003 | 0,005 |
| Intégrité de la recherche | 0,034 | 0,017 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,010 | 0,002 |
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 ».