Carotid artery occlusion and colateral circulation in C57black/6J mice detected by synchrotron radiation microangiography

Using monochromatic synchrotron radiation, we performed microangiography inC57BL/6J mice and investigated their vasculature after unilateral and bilateral carotidartery occlusion. Bilateral occlusion of the carotid artery was made by a ligation of theleft common carotid artery followed by a ligation of the right internal carotid artery(ICA) two days later (n=12). Five days after the second surgery, angiography wasperformed. Unilateral occlusion was made by clipping the right ICA and thenangiography was performed immediately (n=5). The control mice did not undergo anyocclusion (n=5). We removed the brain of the bilateral occlusion mice afterangiography and examined the infarction area. The cerebral microvessels in all animalswere clearly visualized. In the control mice, the posterior communicating artery (Pcom)was not visualized. In the unilateral occlusion mice, the anastomosis of thepterygopalatine artery (PPA) and the external carotid artery (ECA) were recognized.The PPA is thus considered to play a role in the collateral vessel between the ICA andthe ECA. The Pcom was not visualized. In the bilateral occlusion mice, the Pcom wasobserved either unilateraly (n=5) or bilateraly (n=5). The Pcom supplied blood flow tothe anterior circulation from the vertebrobasilar arteries. The bilateral occlusion micethat had at least one visualized Pcom did not have any infarction. We could successfullyvisualize the cerebral vasculature of normal mice and carotid artery occluded mice inan in vivo study. Microangiography can demonstrate the development of vasculatureand the blood flow dynamics in mice

Endovascular coil embolization for recurrence of intracranial aneurysms more than 10 years after clipping

We report three cases of endovascular coil embolization for recurrent cerebral aneurysm after neck clipping more than 10 years previously. In two cases, their first subarachnoid hemorrhage was treated in other hospitals and the details of follow-up after discharge were unknown. After their second subarachnoid hemorrhage recurred 15 and 30 years, respectively. The remaining patient, who was treated in our center, was followed by magnetic resonance imaging 5 years after surgery but since then she didn′t go to our center. She came to our center for follow-up examination 10 years after the first surgery. The digital subtraction angiography showed recurrence of clipped aneurysms in all patients. All of them underwent endovascular coil embolization and total obliteration of the aneurysms without complications related to the procedures. Endovascular coil embolization is an alternative modality to direct surgery for cerebral aneurysms, especially for recurrence after clipping. Endovascular coil embolization of residual aneurysms after surgery may be the treatment of choice because of the difficulties in second direct surgery. We conclude that it is necessary to perform follow-up evaluations after surgery, even if the complete obliteration of aneurysms is performed. Current medical literature does not provide recommendations for the duration of follow-up after aneurysm clipping. The authors suggest that this period perhaps be at least a decade

Sca-1 and thy-1 accelerate neuron-like differentiation in bone marrow stromal cells

Bone marrow stromal cells taken from EGFP transgenic mice were sorted bymagnetic beads with surface markers for Sca-1 and Thy-1. The cells were thenco-cultured on organotypic hippocampal slice or with neuronal cell feeder in dish. Onhippocampus, both Sca-1 and Thy-1 positive cells showed 4- 8 folds higher potential toshow neuron-like morphology than negative cells. In dish, negative cells fewly survivedbut each positive cells survived and showed neuron-like differentiation. In both culturecondition, retinoic acid supplement accelerate differentiation. Differentiated Sca-1 andThy-1 positive cells were immunohistochemically GFAP- and NeuN-negative butnestin-, neurofilament- and NSE-positive. Neuron-like differentiation of bone marrowcells can be enhanced by selection using cell surface proteins