Rare intraspinal clear cell meningioma in children: a case report and literature review.

Meningioma of the spinal canal is very rare. Clear cell meningioma (CCM) with special histological features occurs more commonly in the spinal cord. A review of the published English-language literature identified 40 reported cases of children with intraspinal CCM and this current report presents an additional case of a 3-year-old child with confirmed lumbar CCM. The current case underwent gross total resection of the CCM. At 9 months after the operation, lumbar magnetic resonance imaging was undertaken and confirmed the absence of tumour recurrence. The child was able to walk normally again. During this period, the child did not receive adjuvant treatments such as radiotherapy and chemotherapy. An evaluation of the 41 cases demonstrated the following: (i) there was no significant difference between the recurrence rate of females and males; (ii) there was a significant difference in the recurrence rate based on the extent of resection (gross total resection versus partial resection); (iii) the recurrence rate in patients where the number of involved segments ≥3 levels was significantly higher than that in patients where the number of involved segments was 1-2 levels. For children with CCM, complete surgical resection might be an important characteristic for predicting the risk of the recurrence of CCM.

Knockdown of P120 catenin aggravates endothelial injury under an impinging flow by inducing breakdown of adherens junctions.

At present, the mechanisms underlying intracranial aneurysm (IA) development remain unclear; however, hemodynamics is considered a crucial factor in the induction of IA. To elucidate the association between hemodynamics and endothelial cell (EC) functions, a modified T chamber system was designed to simulate the adjustable hemodynamic conditions of an artery bifurcation. Normal human umbilical vein ECs (HUVECs) and HUVECs with P120 catenin (P120ctn) knockdown were cultured on coverslips and placed in the chamber. A flow rate of 250 or 500 ml/min impinged on the cell layer. Subsequently, the expression levels of P120ctn and other proteins, and EC morphological alterations, were examined. In normal HUVECs, after 3 h under a flow rate of 500 ml/min, the expression levels of P120ctn, vascular endothelial (VE)­Cadherin, Kaiso and α­catenin were decreased, whereas matrix metalloproteinase­2 (MMP­2) was increased. In HUVECs with P120ctn knockdown, the period during which ECs adhered to the coverslip was reduced to 1 h under a flow rate of 500 ml/min. In addition, the expression levels of VE­Cadherin, Kaiso and α­catenin in ECs were decreased, whereas those of MMP­2 were increased after 1 h; more prominent alterations were detected under a 500 ml/min flow rate compared with a 250 ml/min flow rate. Adherens junctions (AJs) are critical to the maintenance of normal morphology and EC functioning in the vascular wall, and P120ctn is an important regulator of AJs. Loss of P120ctn may be induced by hemodynamic alterations. In response to changes in hemodynamic conditions, a loss of P120ctn may aggravate AJs between ECs, thus inducing inflammation in the vascular wall. Clinically, hemodynamic alterations may result in a loss of P120ctn and endothelial injury; therefore, P120ctn may have a critical role in inducing intracranial aneurysms.

[The expression and role of Cathepsin B in intracranial aneurysm wall].

OBJECTIVES: To detect the expression of Cathepsin B (CatB) in the intracranial aneurysm wall and its effect to the apoptosis of vascular smooth muscle cells, aimed at clarifying the pathological formation mechanism of intracranial aneurysm. METHODS: From November 2006 to February 2009, 20 intracranial aneurysm samples were collected as the experimental group, and 6 cases of normal pallium artery samples were collected as the control group. Immunohistochemical technique was used to evaluate the expressions of CatB, alpha-smooth muscle actin (alpha-SMA) and Caspase-3. The expression of CatB mRNA was evaluated by real-time PCR. The ultrastructure of intracranial aneurysms were observed by using the transmission electronic microscope. RESULTS: Compared with the normal pallium artery specimens, the expression of CatB and Caspase-3 both significantly increased in the intracranial aneurysm walls where alpha-SMA decreased (P < 0.05). The mean expression of CatB mRNA in intracranial aneurysm samples was about 3.8-folds than that in control group (P < 0.01). There were excessive apoptotic vascular smooth muscle cells (VSMCs) in the tunica median, and typical apoptotic body were observed in some aneurysm walls. CONCLUSION: Cathepsin B may be involved in the formation and the progression of intracranial aneurysm.