[Study by radiolabelling of the residual time of a therapeutic gel in the nasal fossae]. / Etude par radiomarquage de la rémanence d'un gel thérapeutique dans les fosses nasales.

The residence times in the nose of the liquid and gel forms of the same therapeutic preparation were compared in 7 healthy subjects. A 50 microliters drop of the preparation, labelled with Tc99m, was placed down the head of the inferior turbinate, and the kinetics of its clearance from the site of deposition was monotired using a gamma camera, during 60 minutes for the liquid and 120 minutes for the gel. The average times for removal of 50% of the labelled material from the site of deposition were 10.3 minutes and 28.6 minutes for the liquid and gel forms respectively. The slower removal of the gel form is probably due to a mechanical effect, and seems to affect the whole nasal passage. The contact time between the preparation and the mucosa is increased in this galenic form and this should improve the efficiency of the preparation.

Biointegration of massive bone allografts: imaging and histological studies in cat.

A study was carried out in a cat model to compare three imaging methods (X-ray, bone scintigraphy (BS) and magnetic resonance imaging (MRI] in order to assess the healing of bone allografts. X-ray remains the first technique to proceed, for morphological information and control of devices. BS is very sensitive although unspecific and difficult to quantify in exploration of bone reconstruction. It may be a useful complement of X-ray methods in some pathological circumstances (stress fracture, infection, non union). MRI is a very sensitive exploration of the bone marrow, but not of the cortical bone. In its present state it is of little value in bone graft imaging because of its low specificity and because of metallic artefacts (material, micro particles).

Anti-inflammatory activity of various superoxide dismutases on polyarthritis in the Lewis rat.

The anti-arthritic activity of four superoxide dismutases (SODs) has been compared by using the adjuvant-induced polyarthritis rat model. Many of the clinical signs observed in the rat closely resemble those of human rheumatic diseases and the Fiessinger-Leroy-Reiter syndrome. An original protocol and various approaches allowed study of the evolution of long term (30-90 days) SOD treatment. Results are relevant to clinical application: human and bovine Cu-SODs are fully active during secondary and tertiary arthritic reaction; homologous rat Cu-SOD is active only transiently at the end of the secondary reaction; human Mn-SOD is active only on the second stage of arthritic reaction. It should be noted that bovine and human SODs slightly delay the appearance of bony damage. These data were confirmed by the scintigraphic study. Finally it is noteworthy that drug pharmacological activity decreases when the blood level of anti-SOD antibodies increases. This indicates the existence of an immunological reaction following SOD administration.