Arteriovenous malformations (AVMs) within the spinal canal and in the paraspinal region are unusu... more Arteriovenous malformations (AVMs) within the spinal canal and in the paraspinal region are unusual. Spinal cord and dural AVMs or arteriovenous fistulas have been the subject of numerous reports, but paraspinal malformations causing venous congestion or hemorrhage in the spinal canal are rare and present special diagnosis and management challenges. The authors review previously published reports on 16 children with paraspinal AVMs. They also describe the 17th case of a child with a paraspinal AVM who presented with a spontaneous spinal epidural hematoma. To the best of the authors' knowledge, there has been no other case of a spinal epidural hematoma associated with a paraspinal AVM. In each of the 17 cases, the vascular lesion was successfully obliterated using endovascular therapy. Embolization with permanent occlusive agents is an effective treatment for these rare but potentially debilitating lesions.
Currently, no diagnostic or treatment standards exist for extracranial carotid artery dissection ... more Currently, no diagnostic or treatment standards exist for extracranial carotid artery dissection (CAD) in children after trauma. The purpose of this study was to review and describe the characteristics, diagnosis, and treatment of this rather uncommon sequelae of pediatric trauma. A systematic review of the literature was performed to examine the pertinent studies of traumatic extracranial carotid artery (CA) injuries in children. No randomized trials were identified; however, 19 case reports or small case series consisting of 34 pediatric patients were found in the literature. The diagnosis of CAD was made in 33 of 34 patients only after the onset of ischemic symptomatology. Twenty-four of 34 patients underwent cerebral angiography to confirm diagnosis; MR angiography affirmed the diagnosis in 6 of 34 patients. There was little published experience with CA ultrasonography or CT angiography for diagnosis. Thirty of 34 patients were treated with medical therapy or observation; 2 of 4 patients treated with observation alone died. There was little experience with open surgical treatment of CAD in the pediatric population, and there were no studies on the endovascular treatment of traumatic CAD in children. The literature does not support anticoagulation therapy over antiplatelet therapy. As a result of this review of the literature, the authors propose the algorithms for the evaluation and treatment of traumatic extracranial CADs in children. These recommendations include utilizing MR angiography as a screening tool in cases in which the clinical suspicion of CAD is high, using conventional cerebral angiography to confirm the diagnosis, implementing antiplatelet therapy as initial medical management, and reserving endovascular stenting in cases of failed medical treatment.
Interleukin-11 (IL-11) and its receptor (IL-11R) involve in many normal and abnormal biological p... more Interleukin-11 (IL-11) and its receptor (IL-11R) involve in many normal and abnormal biological progress. Studies strongly suggest that interleukin-11 (IL-11) plays an important role in early bone metastases. We synthesized an IL-11Rα homing peptide identified from in vivo patient screening with a peptide phage display and to conjugate it to both an NIR dye for optical imaging and a chelator for nuclear imaging. Cell binding and internalization of the imaging agent was evaluated using NIR confocal microscopy and human breast cancer MDA-MB-231 cell lines. Specificity was demonstrated by comparing with free dye and blocking with the unlabeled recombinant IL-11. Tumor cell growth, vasculature formation and IL-11 agent binding to the tumor were demonstrated in vivo using luciferase positive tumor xenograft model and the injection of both vasculature and IL-11 agents. Tissue autoradiography and H&E staining of the same tissue sections were conducted to verify imaging data. Biodistribution was analyzed by percentage injection dose per gram tissue. Confocal microscopy demonstrated that the target specific imaging agent accumulated on the cell membrane and internalized into cell while free dye had significant lower cell binding than the IL-11 agent. Pre-incubated by the presence of IL-11 protein significantly decreased the agent binding to the cell. Multienergy in vivo imaging revealed the tumor growth, vasculature formation and IL-11 agent binding on the tumor as early as 4 days after the tumor cell inoculation. Overlaid the autoradiography tissue image with H&E staining results demonstrated the heterogeneous distribution of the imaging agent inside tumor mass. Furthermore, the images showed the IL-11 agent only bound to the viable tumor cells. These results suggest a potential imaging agent for study IL-11Rα expression at noninvasive whole body level as well as organ, tissue and cellular levels. *WW, XQ: These authors contributed equally to this work. Grant support: DoD W81XWH-08-1-0489, Department of Defense, Department of Radiology research fund, Curtis Hankamer Basic Research Fund and the L.E. and Josephine S. Gordy Memorial Cancer Research Fund, Dan L. Duncan Cancer Center Scholar, American Society for Clinical Oncology and Hope Street Kids Foundation, and National Science Foundation of China grants (30471988, 30973409, and 30873027). Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5233.
La terapia degli aneurismi giganti senza colletto è attualmente basata sulla chiusura chirurgica ... more La terapia degli aneurismi giganti senza colletto è attualmente basata sulla chiusura chirurgica o endovascolare del vaso principale eventualmente preceduta da by-pass nel caso di insufficiente compenso di circolo collaterale . La recente introduzione di stent per utilizzo intracranico e di nuovi agenti embolizzanti offre una alternativa alla chiusura del vaso. Il posizionamento dello stent in corrispondenza del presunto colletto aneurismatico permette infatti la “ricostruzione” anatomica del vaso; l’obliterazione della sacca aneurismatica può essere ottenuta successivamente con agenti embolizzanti .
Arteriovenous malformations (AVMs) within the spinal canal and in the paraspinal region are unusu... more Arteriovenous malformations (AVMs) within the spinal canal and in the paraspinal region are unusual. Spinal cord and dural AVMs or arteriovenous fistulas have been the subject of numerous reports, but paraspinal malformations causing venous congestion or hemorrhage in the spinal canal are rare and present special diagnosis and management challenges. The authors review previously published reports on 16 children with paraspinal AVMs. They also describe the 17th case of a child with a paraspinal AVM who presented with a spontaneous spinal epidural hematoma. To the best of the authors' knowledge, there has been no other case of a spinal epidural hematoma associated with a paraspinal AVM. In each of the 17 cases, the vascular lesion was successfully obliterated using endovascular therapy. Embolization with permanent occlusive agents is an effective treatment for these rare but potentially debilitating lesions.
Currently, no diagnostic or treatment standards exist for extracranial carotid artery dissection ... more Currently, no diagnostic or treatment standards exist for extracranial carotid artery dissection (CAD) in children after trauma. The purpose of this study was to review and describe the characteristics, diagnosis, and treatment of this rather uncommon sequelae of pediatric trauma. A systematic review of the literature was performed to examine the pertinent studies of traumatic extracranial carotid artery (CA) injuries in children. No randomized trials were identified; however, 19 case reports or small case series consisting of 34 pediatric patients were found in the literature. The diagnosis of CAD was made in 33 of 34 patients only after the onset of ischemic symptomatology. Twenty-four of 34 patients underwent cerebral angiography to confirm diagnosis; MR angiography affirmed the diagnosis in 6 of 34 patients. There was little published experience with CA ultrasonography or CT angiography for diagnosis. Thirty of 34 patients were treated with medical therapy or observation; 2 of 4 patients treated with observation alone died. There was little experience with open surgical treatment of CAD in the pediatric population, and there were no studies on the endovascular treatment of traumatic CAD in children. The literature does not support anticoagulation therapy over antiplatelet therapy. As a result of this review of the literature, the authors propose the algorithms for the evaluation and treatment of traumatic extracranial CADs in children. These recommendations include utilizing MR angiography as a screening tool in cases in which the clinical suspicion of CAD is high, using conventional cerebral angiography to confirm the diagnosis, implementing antiplatelet therapy as initial medical management, and reserving endovascular stenting in cases of failed medical treatment.
Interleukin-11 (IL-11) and its receptor (IL-11R) involve in many normal and abnormal biological p... more Interleukin-11 (IL-11) and its receptor (IL-11R) involve in many normal and abnormal biological progress. Studies strongly suggest that interleukin-11 (IL-11) plays an important role in early bone metastases. We synthesized an IL-11Rα homing peptide identified from in vivo patient screening with a peptide phage display and to conjugate it to both an NIR dye for optical imaging and a chelator for nuclear imaging. Cell binding and internalization of the imaging agent was evaluated using NIR confocal microscopy and human breast cancer MDA-MB-231 cell lines. Specificity was demonstrated by comparing with free dye and blocking with the unlabeled recombinant IL-11. Tumor cell growth, vasculature formation and IL-11 agent binding to the tumor were demonstrated in vivo using luciferase positive tumor xenograft model and the injection of both vasculature and IL-11 agents. Tissue autoradiography and H&E staining of the same tissue sections were conducted to verify imaging data. Biodistribution was analyzed by percentage injection dose per gram tissue. Confocal microscopy demonstrated that the target specific imaging agent accumulated on the cell membrane and internalized into cell while free dye had significant lower cell binding than the IL-11 agent. Pre-incubated by the presence of IL-11 protein significantly decreased the agent binding to the cell. Multienergy in vivo imaging revealed the tumor growth, vasculature formation and IL-11 agent binding on the tumor as early as 4 days after the tumor cell inoculation. Overlaid the autoradiography tissue image with H&E staining results demonstrated the heterogeneous distribution of the imaging agent inside tumor mass. Furthermore, the images showed the IL-11 agent only bound to the viable tumor cells. These results suggest a potential imaging agent for study IL-11Rα expression at noninvasive whole body level as well as organ, tissue and cellular levels. *WW, XQ: These authors contributed equally to this work. Grant support: DoD W81XWH-08-1-0489, Department of Defense, Department of Radiology research fund, Curtis Hankamer Basic Research Fund and the L.E. and Josephine S. Gordy Memorial Cancer Research Fund, Dan L. Duncan Cancer Center Scholar, American Society for Clinical Oncology and Hope Street Kids Foundation, and National Science Foundation of China grants (30471988, 30973409, and 30873027). Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5233.
La terapia degli aneurismi giganti senza colletto è attualmente basata sulla chiusura chirurgica ... more La terapia degli aneurismi giganti senza colletto è attualmente basata sulla chiusura chirurgica o endovascolare del vaso principale eventualmente preceduta da by-pass nel caso di insufficiente compenso di circolo collaterale . La recente introduzione di stent per utilizzo intracranico e di nuovi agenti embolizzanti offre una alternativa alla chiusura del vaso. Il posizionamento dello stent in corrispondenza del presunto colletto aneurismatico permette infatti la “ricostruzione” anatomica del vaso; l’obliterazione della sacca aneurismatica può essere ottenuta successivamente con agenti embolizzanti .
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Papers by Michel Mawad