Scintigraphie à l’OctréoScan® : aspects pratiques. Le point de vue du manipulateur

Evaluation of neuroendocrine tumors extent comprises a somatostatin receptor scintigraphy with OctréoScan^®. This examination begins with the radiopharmaceutical preparation and its quality control (dose, visual appearance, radiochemical purity, pH). The radiopharmaceutical is administered intravenously at a slow rate with respect of the contra-indications and recommendations. The patient's good respect of low residue diet and digestive preparations is essential for a good imaging quality. In addition, the technologist's psychological role (particularly for people suffering from claustrophobia) and adequate procedures must be taken into account. Several days are necessary to perform the examination that comprises whole body and planar (thoracic and abdominal) views, combined SPECT-CT imaging. This hybrid modality using fused images allows a good anatomical localisation of focal areas of increased uptake even in case of faint uptake. Some false-positive can be avoided (colonic stasis, gall bladder). SPECT-CT contribution to the diagnosis is certain.     

Chelonus sp. near curvimaculatus venom proteins: Analysis of their potential role and processing during development of host Trichoplusia ni

The venom that Chelonus sp. near curvimaculatus injects into each parasitized Trichoplusia ni egg is entirely injected within the first 8 s of the 19-s oviposition period, before deposition of the parasitoid egg that is injected during the final 1-2 s of the oviposition. The parasitization factor, causing precocious metamorphosis of the host, is injected after the venom, but before the parasite egg. The venom by itself does not cause developmental redirection of the host. Chelonus venom proteins are very stable in the host egg during the first 2 days of egg development. Then, on the last day before hatching, they are rapidly degraded by the proteolytic enzymes appearing in 3-day-old T. ni eggs. Among those that degrade the venom proteins are serine-type proteinases, and at least one seems to be a trypsin-like enzyme.