We have identified and partially characterized several gelatinase activities associated with the sea urchin extraembryonic matrix, the hyaline layer. A previously identified 41-kDa collagenase/gelatinase activity was generally not found to be associated with isolated hyaline layers but was dissociated from the surface of 1-h-old embryos in the absence of Ca2+ and Mg2+. While hyaline layers, freshly prepared from 1-h-old embryos, were devoid of any associated gelatinase activities, upon storage at 4 degrees C for 4 days, a number of gelatin-cleavage activities appeared. Comparative analysis of these activities with the 41-kDa collagenase/gelatinase revealed that all species were inhibited by ethylenediamine tetraacetic acid but were refractory to inhibition with the serine protease inhibitors, phenylmethyl sulfonyl fluoride and benzamidine. In contrast, the largely Zn2+ specific chelator 1,10-phenanthroline had markedly different effects on the gelatinase activities. While several of the storage-induced, hyaline-layer-associated gelatinase activities were inhibited, the 41-kDa collagenase/gelatinase was refractory to inhibition as was a second gelatinase species with an apparent molecular mass of 45 kDa. We also examined the effects of a series of divalent metal ions on the gelatin-cleavage activities. In both qualitative and quantitative assays, Ca2+ was the most effective activator while Mn2+, Cu2+, Cd2+, and Zn2+ were all inhibitory. In contrast, Mg2+ had a minimal inhibitory effect on storage-induced gelatinase activities but significantly inhibited the 41-kDa collagenase/gelatinase. These results identify several distinct gelatin-cleavage activities associated with the sea urchin extraembryonic hyaline layer and point to diversity in the biochemical nature of these species.

Internal carotid artery (ICA) covered stent-grafts are increasingly utilized for the endovascular management of traumatic carotid pseudoaneurysms 1 " 9 , carotid-cavernous fistulas 1012 , large petrous/cavernous carotid aneurysms 12 and carotid blow-out syndrome 7 . Early covered stent grafts were selffabricated using polytetrafluoroethylene or autologous vein mounted onto bare metal stents. Pre-mounted balloon expandable or self-expanding stent-grafts are now commercially available. Covered stents provide an alternate treatment option for high surgical risk or inaccessible lesions or when observation and anticoagulation are less than desirable. Potential advantages of covered stent grafts include minimal invasiveness, shorter hospital stays, lower cost and less post-procedural pain. Caution in the application of this relatively new technology and careful follow-up are required, however, as is illustrated by two patients with internal carotid artery stenosis following covered stent-graft placement. Case IA 24-year-old previously healthy right-handed woman was the belted driver in a vehicle roll-over. She sustained multiple injuries including fractures of the odontoid process of C2 and the left transverse process of C7. A computed tomogram (CT) head performed at the time of admission was unremarkable. The patient was sedated, intubated and treated with hypothermia according to the institutional protocol. As the sedation dissipated 24-hours later, the patient was found to be aphasic with mild right-sided face and arm weakness. A repeat CT head demonstrated a subacute left fronto-temporal infarct and CT angiography revealed left internal carotid artery (ICA) occlusion, presumed to be secondary to arterial dissection. Antiplatelet therapy was initiated at this time.The patient made a good functional recovery with significant improvement in speech and complete recovery of motor function. A one-month follow-up CT angiogram demonstrated recanalization of the left ICA but development of a pseudoaneurysm at the level of the first cervical vertebrae. Serial noninvasive angiography over three months demonstrated progressive enlargement of the pseudoaneurysm and consequently the patient was referred for endovascular management to prevent its continued expansion and decrease the future risk of a recurrent ischemic event.Given the angio-architecture of the pseudoaneurysm, covered stent graft placement or vessel occlusion were considered as the safest and effective treatment options. An approach preserving

We have identified and partially characterized several gelatinase activities associated with the sea urchin extraembryonic matrix, the hyaline layer. A previously identified 41-kDa collagenase/gelatinase activity was generally not found to be associated with isolated hyaline layers but was dissociated from the surface of 1-h-old embryos in the absence of Ca2+ and Mg2+. While hyaline layers, freshly prepared from 1-h-old embryos, were devoid of any associated gelatinase activities, upon storage at 4 degrees C for 4 days, a number of gelatin-cleavage activities appeared. Comparative analysis of these activities with the 41-kDa collagenase/gelatinase revealed that all species were inhibited by ethylenediamine tetraacetic acid but were refractory to inhibition with the serine protease inhibitors, phenylmethyl sulfonyl fluoride and benzamidine. In contrast, the largely Zn2+ specific chelator 1,10-phenanthroline had markedly different effects on the gelatinase activities. While several of the storage-induced, hyaline-layer-associated gelatinase activities were inhibited, the 41-kDa collagenase/gelatinase was refractory to inhibition as was a second gelatinase species with an apparent molecular mass of 45 kDa. We also examined the effects of a series of divalent metal ions on the gelatin-cleavage activities. In both qualitative and quantitative assays, Ca2+ was the most effective activator while Mn2+, Cu2+, Cd2+, and Zn2+ were all inhibitory. In contrast, Mg2+ had a minimal inhibitory effect on storage-induced gelatinase activities but significantly inhibited the 41-kDa collagenase/gelatinase. These results identify several distinct gelatin-cleavage activities associated with the sea urchin extraembryonic hyaline layer and point to diversity in the biochemical nature of these species.

CTNB offers a high yield in establishing a histopathologic diagnosis of subsolid pulmonary lesions, with both ground-glass and solid-predominance. The pure ground-glass category of lesions requires further research to determine the true diagnostic yield and diagnostic accuracy of core needle biopsies.