French Institute of Health and Medical Research

About: French Institute of Health and Medical Research is a government organization based out in Paris, France. It is known for research contribution in the topics: Population & Receptor. The organization has 109367 authors who have published 174236 publications receiving 8365503 citations.

Nanoprobes with near-infrared persistent luminescence for in vivo imaging.

Abstract: Fluorescence is increasingly used for in vivo imaging and has provided remarkable results. Yet this technique presents several limitations, especially due to tissue autofluorescence under external illumination and weak tissue penetration of low wavelength excitation light. We have developed an alternative optical imaging technique by using persistent luminescent nanoparticles suitable for small animal imaging. These nanoparticles can be excited before injection, and their in vivo distribution can be followed in real-time for more than 1 h without the need for any external illumination source. Chemical modification of the nanoparticles' surface led to lung or liver targeting or to long-lasting blood circulation. Tumor mass could also be identified on a mouse model.

Neural cell adhesion molecules and myelin-associated glycoprotein share a common carbohydrate moiety recognized by monoclonal antibodies L2 and HNK-1.

Abstract: Cell surface molecules have been implicated in cell interactions which underlie formation of the nervous system. The analysis of the functional properties of such molecules has profited from the combined use of antibodies and cell culture systems. It has been suggested that the interplay between these molecules modulates cell-to-cell interaction at critical developmental stages. In the mouse, N-CAM and L1 antigen have been shown to mediate Ca2+-independent adhesion among neural cells. N-CAM plays a role in fasciculation of neurites and formation of neuromuscular junction. L1 is apparently not involved in synaptogenesis, but in migration of granule cell neurones in the developing mouse cerebellar cortex. The two antigens are distinct molecular and functional entities which act synergistically in aggregation of neuroblastoma and early postnatal cerebellar cells. In view of a certain similarity in function between the two groups of molecules, it was not surprising to find that structural similarities are detectable by the monoclonal antibody L2. We show here that a carbohydrate moiety recognized by L2 and HNK-1 monoclonal antibodies, is present in mouse N-CAM and L1. The L2 epitope appears on all major neural cell types but not all N-CAM molecules express it. This heterogeneity points to a previously undetected molecular diversity which may have functional implications for modulating cell adhesion during development.

A Barycentremetric study of the sagittal shape of spine and pelvis: the conditions required for an economic standing position.

Abstract: The standing posture of 17 young men and women were studied using Barycentremeter measurements and full spine radiograph with a single referential system. These procedures provide in vivo measurements of the weight and center of weight supported by each vertebra and the coxofemoral joints. The relationship between the vertebra, the sacrum or the coxofemoral rotation axis and the center of weight they support, is displayed. The moment of the corresponding force may also be assessed. Mean values were computed and the relation with spine sagittal curves and pelvic parameters were studied. The position of the center of weight, in front of or behind the vertebra or the coxofemoral joints, requires an opposing muscle force to ensure mechanical stability. The load exerted on the vertebra cannot be precisely evaluated, but we can describe the way in which these loads vary when the spinal curves and the pelvic slope change. This study provides basic data suggesting that there is a tendency to maintain the body in the most economical position in terms of muscle fatigue and vertebral strain. Individual anatomical shapes and pelvic parameters of the pelvis induce corresponding specific sagittal curves of the spine. This concept is very useful for analysing pathological situations and devising appropriate treatment.