The Proteolipid Protein Promoter Drives Expression outside of the Oligodendrocyte Lineage during Embryonic and Early Postnatal Development

The proteolipid protein (Plp) gene promoter is responsible for driving expression of one of the major components of myelin – PLP and its splice variant DM-20. Both products are classically thought to express predominantly in oligodendrocytes. However, accumulating evidence suggests Plp expression is more widespread than previously thought. In an attempt to create a mouse model for inducing oligodendrocyte-specific gene deletions, we have generated transgenic mice expressing a Cre recombinase cDNA under control of the mouse Plp promoter. We demonstrate Plp promoter driven Cre expression is restricted predominantly to mature oligodendrocytes of the central nervous system (CNS) at postnatal day 28. However, crosses into the Rosa26LacZ and mT/mG reporter mouse lines reveal robust and widespread Cre activity in neuronal tissues at E15.5 and E10.5 that is not strictly oligodendrocyte lineage specific. By P28, all CNS tissues examined displayed high levels of reporter gene expression well outside of defined white matter zones. Importantly, our study reinforces the emerging idea that Plp promoter activity is not restricted to the myelinating cell lineage, but rather, has widespread activity both during embryonic and early postnatal development in the CNS. Specificity of the promoter to the oligodendrocyte cell lineage, as shown through the use of a tamoxifen inducible Plp-CreERt line, occurs only at later postnatal stages. Understanding the temporal shift in Plp driven expression is of consequence when designing experimental models to study oligodendrocyte biology

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Endovascular treatment of carotid artery stenosis: retrospective study of 79 patients treated with stenting and angioplasty with and without cerebral protection devices Tratamento endovascular das lesões estenóticas em bifurcação carotídea: estudo retrospectivo de 79 pacientes tratados por "stent" e angioplastia com e sem mecanismos de proteção cerebral

We evaluate the results of stenting and angioplasty on carotid bifurcation stenotic lesions using protection systems, emphasizing the indications and technical aspects. Seventy-nine patients, mean age 64.5 years were treated from February,1998 to March, 2003. All patients were included in NASCET study criteria. Forty three patients were treated without the protection systems and thirty six were treated with carotid protection filtering system (Angioguard, EPI). Technical success and 6-months carotid Doppler ultrasound follow-up showing stent patency were achieved in all patients. One major stroke and one death due to intracranial reperfusion bleeding occurred in patients treated without cerebral protection devices. Only one patient presenting hyper perfusion syndrome improving after 7 days, was found in the group treated with the cerebral protection filter mechanism, no other neurologic symptom or death occured in this group. Stenting and angioplasty with protection systems for thromboembolic debris is a safe endovascular method to treat stenotic lesions in the carotid bifurcation with low morbidity and mortality.<br>Este estudo mostra a experiência e resultados da terapêutica endovascular nas lesões estenóticas em bifurcação carotídea. Entre fevereiro de 1998 e março de 2003 foram tratados 79 pacientes com idades entre 57 e 72 anos (média 64,5 anos) sendo 45 do masculino e 34 do feminino. Todos os pacientes enquadravam-se nos critérios do estudo "NASCET" com comprometimento das artérias carótidas internas. Dos 79 pacientes, 43 foram tratados sem os sistemas de proteção e 36 pacientes foram tratados com sistema de proteção. Dos 36 pacientes tratados com sistema de proteção foram utilizados filtros de proteção (Angioguard e EPI). Observou-se melhora angiográfica em todos os 79 pacientes tratados. Ultrasom Doppler realizado após 6 meses mostrou artérias pérvias em todos os pacientes. Nos 43 pacientes tratados por "stent"/angioplastia sem a utilização de sistemas de proteção tivemos um paciente com déficit neurológico que perdurou por mais de 30 dias ("stroke major") e um óbito por transformação hemorrágica devido à reperfusão. Ocorreu síndrome de hiperperfusão em 1 paciente dos 36 pacientes tratados com o sistema de proteção, regredindo em 7 dias, sendo que nos demais não houve morbi-mortalidade. A angioplastia e "stent" no território carotídeo com a utilização de sistema de proteção é um método seguro com reduzida morbidade e mortalidade estando indicada nas lesões estenóticas das bifurcações carotídeas