Human immortalized chondrocytes carrying heterozygous FGFR3 mutations: An in vitro model to study chondrodysplasias

AbstractAchondroplasia and thanatophoric dysplasia are human chondrodysplasias caused by mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. We have developed an immortalized human chondrocyte culture model to study the regulation of chondrocyte functions. One control and eight mutant chondrocytic lines expressing different FGFR3 heterozygous mutations were obtained. FGFR3 signaling pathways were modified in the mutant lines as revealed by the constitutive activation of the STAT pathway and an increased level of P21WAF1/CIP1 protein. This model will be useful for the study of FGFR3 function in cartilage studies and future therapeutic approaches in chondrodysplasias

Characterization of Fabric-to-Fabric Friction: Application to Medical Compression Bandages

Fabric-to-fabric friction is involved in the action mechanism of medical compression devices such as compression bandages or lumbar belts. To better understand the action of such devices, it is essential to characterize, in their use conditions (mainly pressure and stretch), the frictional properties of the fabrics they are composed of. A characterization method of fabric-to-fabric friction was developed. This method was based on the customization of the fourth instrument of the Kawabata Evaluation System, initially designed for fabric roughness and friction characterization. A friction contactor was developed so that the stretch of the fabric and the applied load can vary to replicate the use conditions. This methodology was implemented to measure the friction coefficient of several medical compression bandages. In the ranges of pressure and bandage stretch investigated in the study, bandage-to-bandage friction coefficient showed very little variation. This simple and reliable method, which was tested for commercially available medical compression bandages, could be used for other medical compression fabrics

La réactivité des lapereaux à la phéromone mammaire : un indicateur de viabilité ?

National audienceL’objectif de cette expérience était d’étudier le lien existant entre le poids et la réponse/non réponse des lapereaux à la phéromone mammaire, et leur ingestion de lait, leur survie et leur croissance. Pour cela, 293 nouveau-nés de 30 portées on été individuellement testés pour leur réactivité à la phéromone mammaire et leur ingestion de lait au lendemain de leur naissance (J1), et suivis pour leur mortalité et leur croissance jusqu’à J21. Environ 90% des lapereaux ont répondu à la phéromone à J1. Les lapereaux non réactifs à la phéromone ingéraient moins de lait et présentaient un taux de mortalité plus élevé que les lapereaux qui y répondaient (P<0,05). Cet impact est modulé par le poids des lapereaux, puisqu’il existait de façon significative chez les nouveau-nés de faible poids à J1 (< 48 g, dans notre étude). Par ailleurs, l’étude a confirmé l’impact positif du poids et de l’ingestion de lait à J1 sur la viabilité et la croissance des lapereaux au cours des 3 premières semaines de vie (P<0,001). Au final, la non réponse à la phéromone mammaire à J1, dans une situation de test comportemental ponctuel, semble être un critère parmi d’autres influant sur la viabilité du jeune lapin en conditions d’élevage, et apparaît potentiellement intéressante pour identifier et isoler les lapereaux à risques dans les populations de petits poids

Composition pour l'alimentation des lapins

N° et date de dépôt : FR0102752 - 2001-02-28 ; n° et date de publication de la demande : FR2821243 - 2002-08-30 (BOPI 2002-35).Cette invention concerne une composition pour l'alimentation des lapins comprenant une base formée d'un aliment liquide ou solide et de 10-9 à 10-4 g de composé de formule générale (I), par gramme de composition totale

The reactivity of neonatal rabbits to the mammary pheromone as a probe for viability

International audienceNewborn rabbits depend on a daily nursing interaction with the mother to gain milk and to survive. During this interaction, they localise and seize the nipples displaying a typical behaviour triggered by maternal odour cues. The mammary pheromone constitutes such a signal in domestic rabbits: it elicits sucking-related movements in more than 90% of the pups. However, some newborns remain unresponsive to the presentation of the pheromone, even pups apparently healthy and highly motivated to suck. The main goal of the present study was therefore to explore the link between the unresponsiveness of rabbit pups to the mammary pheromone and their growth and survival in breeding conditions. To that end, 293 newborns from 30 litters were tested for their head searching-oral grasping responses to the mammary pheromone on days 1 and 3, and their milk intake and mortality were followed up from days 1 to 21. It was hypothesised that unresponsive newborns would have subsequent difficulties in finding nipples, sucking and surviving. Early weight and success in milk intake were further considered as mediating factors in growth and viability. The results showed that pups that were unresponsive to the mammary pheromone on day 1 were less successful in gaining milk and had a higher rate of mortality than the responsive pups. However, this impact was modulated by the weight of pups: it appeared only in the lightest newborns. Moreover, this impact vanished on day 3. On the other hand, the pup weight and sucking success on days 1 to 3 strongly influenced viability and growth during the period extending from days 1 to 21. Taken together, the results show that the day-1 responsiveness of rabbit pups to the mammary pheromone can be considered as an indicator of individual viability in pups having a small weight (,48 g on day 1). The predictive validity of the pups’ pheromonal reactivity seems however time-limited as it works only during the first, but crucial, postnatal days

The reactivity of neonatal rabbits to the mammary pheromone as a probe for viability

International audienceNewborn rabbits depend on a daily nursing interaction with the mother to gain milk and to survive. During this interaction, they localise and seize the nipples displaying a typical behaviour triggered by maternal odour cues. The mammary pheromone constitutes such a signal in domestic rabbits: it elicits sucking-related movements in more than 90% of the pups. However, some newborns remain unresponsive to the presentation of the pheromone, even pups apparently healthy and highly motivated to suck. The main goal of the present study was therefore to explore the link between the unresponsiveness of rabbit pups to the mammary pheromone and their growth and survival in breeding conditions. To that end, 293 newborns from 30 litters were tested for their head searching-oral grasping responses to the mammary pheromone on days 1 and 3, and their milk intake and mortality were followed up from days 1 to 21. It was hypothesised that unresponsive newborns would have subsequent difficulties in finding nipples, sucking and surviving. Early weight and success in milk intake were further considered as mediating factors in growth and viability. The results showed that pups that were unresponsive to the mammary pheromone on day 1 were less successful in gaining milk and had a higher rate of mortality than the responsive pups. However, this impact was modulated by the weight of pups: it appeared only in the lightest newborns. Moreover, this impact vanished on day 3. On the other hand, the pup weight and sucking success on days 1 to 3 strongly influenced viability and growth during the period extending from days 1 to 21. Taken together, the results show that the day-1 responsiveness of rabbit pups to the mammary pheromone can be considered as an indicator of individual viability in pups having a small weight (,48 g on day 1). The predictive validity of the pups’ pheromonal reactivity seems however time-limited as it works only during the first, but crucial, postnatal days

Le lapereau en développement : données comportementales, alimentaires et sensorielles sur la période naissance-sevrage

Synthèse du chapitre écrit par les auteurs pour le Congrès Mondial de Cuniculture (Coureaud et al 2008b)National audienceBlind and deaf at birth, rabbit newborns need, as all mammal newborns, to rapidly interact with the mother to find the nipples and suck. This usually occurs only once per day, during an interaction drastically limited in time, both in domestic and natural conditions. After days 10-15, the mother-young interactions change progressively, leading to weaning between 4 and 6 weeks. In this context of rapid development of the young, lactating rabbit females and pups have developed some sensory, physiological and behavioural adaptations allowing them to communicate, and allowing the young to ingest milk then solid food efficiently. Here, we present some of these adaptations, taking examples from experimental studies run by several groups during the last decades. This paper is a summary of a chapter and communication recently presented during the last World Rabbit Congress (Coureaud et al 2008b).Aveugles et sourds à la naissance, les lapins nouveau-nés doivent, comme tous les mammifères nouveau-nés, interagir rapidement avec la mère afin de trouver rapidement une tétine et téter. Cela se produit généralement une seule fois par jour, au cours d’une très brève interaction, en conditions d’élevage comme en milieu naturel. Après les 10-15 j qui suivent la naissance, la relation mère-jeunes évolue progressivement, et conduit habituellement au sevrage entre 4 et 6 semaines. Dans ce contexte de développement rapide des jeunes, les femelles allaitantes et les lapereaux ont développé des adaptations sensorielles, physiologiques et comportementales leur permettant de communiquer, et permettant aux jeunes d’ingérer efficacement le lait puis les aliments solides. Ici, nous présentons quelques-unes de ces adaptations, en prenant des exemples d’études expérimentales conduites par différents groupes au cours des dernières décennies. Cet article est une synthèse du chapitre écrit par les auteurs pour le Congrès Mondial de Cuniculture (Coureaud et al 2008b)

Characterization of Fabric-to-Fabric Friction: Application to Medical Compression Bandages

Fabric-to-fabric friction is involved in the action mechanism of medical compression devices such as compression bandages or lumbar belts. To better understand the action of such devices, it is essential to characterize, in their use conditions (mainly pressure and stretch), the frictional properties of the fabrics they are composed of. A characterization method of fabric-to-fabric friction was developed. This method was based on the customization of the fourth instrument of the Kawabata Evaluation System, initially designed for fabric roughness and friction characterization. A friction contactor was developed so that the stretch of the fabric and the applied load can vary to replicate the use conditions. This methodology was implemented to measure the friction coefficient of several medical compression bandages. In the ranges of pressure and bandage stretch investigated in the study, bandage-to-bandage friction coefficient showed very little variation. This simple and reliable method, which was tested for commercially available medical compression bandages, could be used for other medical compression fabrics