Study of uranium transfer across the blood-brain barrier.

Uranium is a heavy metal which, following accidental exposure, may potentially be deposited in human tissues and target organs, the kidneys and bones. A few published studies have described the distribution of this element after chronic exposure and one of them has demonstrated an accumulation in the brain. In the present study, using inductively coupled plasma mass spectrometry (ICP-MS) for the quantification of uranium, uranium transfer across the blood-brain barrier (BBB) has been assessed using the in situ brain perfusion technique in the rat. For this purpose, a physiological buffered bicarbonate saline at pH 7.4 containing natural uranium at a given concentration was perfused. After checking the integrity of the BBB during the perfusion, the background measurement of uranium in control rats without uranium in the perfusate was determined. The quantity of uranium in the exposed rat hemisphere, which appeared to be significantly higher than that in the control rats, was measured. Finally, the possible transfer of the perfused uranium not only in the vascular space but also in the brain parenchyma is discussed.

[Quality plan of a bone tissue bank]. / Plan qualité d'une banque de tissus osseux.

In 1994, the French bioethics laws changed the regulations concerning donated human tissues with safety precautions and therapeutic use. The decree of 29(th) December 1998 describes the practical obligations required of bone tissue banks for approval by the French Health Ministry. Before the new regulations, a quality system was implemented at the Cochin hospital bone tissue bank. It integrates quality control for each step of the general process. We describe the quality plan of the Cochin Hospital bone tissue bank and show that the specific quality practices, resources and sequence of activities improve distribution of human bone allografts while maintaining their traceability.

[Functioning of a bone tissue bank in 1998]. / Fonctionnement d'une banque de tissus osseux en 1998.

Last few years, the french legislation and reglementation concerning donated human tissues, safety precautions, and human tissues' uses have been deeply modified. Therefore, tissue banks' organisation, processing of allograft tissue, and the way surgeons use frozen bone graft have changed. Accordingly, authors describe different obligations these activities implicate and practical consequences for tissue banks and surgeons. First, they recall 94' laws and the doctrinal and ethical principles essential to understand current laws and official standards. Then, they specify sanitary rules all tissue banks have to conform to. They detail the different approaches to recovery, processing, preservation and distribution of transplantable bone tissue and expose modalities of the financing by social organisms. It follows practical consequences in bank functioning: supplying, importation, internal organization. In conclusion, authors synthesize surgeon's responsibilities in that specific activity.