Naoki Muramatsu

Rathke cleft cyst: MR and biomedical analysis of cyst content.

PURPOSE At least one type of Rathke cleft cyst has unique MR findings, specifically, high intensity on T1-weighted images and iso- to low intensity on T2-weighted images relative to white matter. To clarify the influence of cyst content on MR images, we analyzed the cyst content by biomedical methods after surgical removal. METHOD We studied five patients diagnosed with Rathke cleft cyst, whose MR images showed high intensity on T1-weighted images and iso- to low intensity on T2-weighted images. After surgery, total protein and cholesterol levels were quantified, and correlations of protein and cholesterol content with T1 and T2 signal intensities were performed in vitro. RESULTS All five cysts had very high concentrations of protein (11,700-26,600 mg/dl, mean 17,940 mg/dl) with nearly no cholesterol (at most 2.0 mg/dl). Along with increases in protein concentration in vitro, the signal intensity of T1-weighted images increased, while that of T2-weighted images decreased. In contrast, the cholesterol concentration sequence influenced the signal intensity of neither T1- nor T2-weighted images. CONCLUSION The unique MR finding of Rathke cleft cysts--high signal intensity on T1-weighted images and low signal intensity on T2-weighted images--might depend mainly on protein concentration, not on cholesterol.

Embolization of a wide-necked basilar bifurcation aneurysm by double-balloon remodeling using HyperForm compliant balloon catheters

We report a patient with a wide-necked basilar bifurcation aneurysm that was difficult to address by standard coil embolization because the left and right posterior cerebral artery (PCA) branched from the base of the aneurysm. To preserve both PCAs, the aneurysm was endovascularly embolized using a double-balloon remodeling technique and HyperForm compliant balloon catheters (MicroTherapeutics, Irvine, CA, USA). The aneurysmal neck was not tightly embolized to avoid coil protrusion into the parent arteries. The present technique is an important adjunct to the embolization of wide-necked basilar bifurcation aneurysms.

COS 1 cell secretes a factor to promote neurite regeneration from transected-nerve terminals of cultured adult DRG

HIDENORI HORIE’, TOSHIHIKO KADOYA*, YOSHIMASA INAGAKI’, YOSHIAKI SOHMA*, RISA NOZAWA2, HITOSHI KAWANO’, MASAO HORIE-‘, IKUKO SAKAI’, KAORI TAKESHITA’, WKI KOWADA’, MITSUHIRO HASEGAWA4, NAOKI MURAMATSU’ , MASAHIKO TAKANO’, HIROMICHI KOYAMA6 Depts. of ‘Physiol. and ‘Ophthalmol , Sch. of Med., and 6College of Nursing, Yokohama City Univ., Yokohama 236-0004, 2Pharmaceut. Res. Lab., KirinBrewery Co.Ltd., Takasaki 370-1295, ‘Deptof Anat Embryo], Tokyo Metropolitan Inst. Neurosci., Tokyo, 183-8526, ‘Dept of Neurosurg. Kanazawa Univ., Sch of Med., Kanazawa, 920-0934, Japan.

1119 Expressions of cadherin/catenin complex in neural tissue

KAZUHITO TOMIZAWA, YUN-FE1 LU, AKIYOSHI MORIWAKI, HIDEKI MATSUI To test a hypothesis that neuronal cdcZlike kinase (Cdk5/p35nck5a) plays imortant roles of synaptic reorganization. we study the kinase activity, expression and the change of subcellular localization in the hipocampi of developing kindled rats. The kinase activity in the kindling rats was much higher comparing with that in the normal adult rats. Developmental changes of the kinase activity correlated with those of the p35nck5a expression in the kindling rats. In constrast, Cdk5 expression was constant throughout development of kindling stages. Subcellular localization of Cdk5 dramatically changed in the developing kindling rats Cdk5 translocated from axon to soma when the kinase activity is high. On the other hand, p35nck5a was always expressed in soma throughout kindling development. The phosphorylation of tau was very agrreement with Cdk5 kinase activity in the developing kindling rats. These data suggest that neuronal cdcZlike kinase physiologicaly play a role of synaptic reorganization.

1309 Localization of e-cadherin in peripheral glia after nerve injury and repair

Multiple functions of the neural cell adhesion molecule Ll have been reported including cell-cell interactions, neurite elongation, axonal fasciculation, cell migration, and myelination. Ll plays important roles in neural development and neuronal regeneration in the peripheral nervous system (PNS). We constructed defective herpes simplex virus (HSV) vectors to express human or rat Ll in cultured primary rat cortical astrocytes. Rat cerebellar neurons co-cultured on a feeder layer of Llexpressing astrocytes demonstrated increased migration and neurite extension compared with neurons co-cultured on control astrocytes. Because this vector system can be used to confer phenotypic changes in primary neural cells, it will be useful for in vitro and in viva studies of neuronal regeneration and plasticity in the central nervous system (CNS).

Skull Base Surgeries for Aneurysms of the Vertebral and Basilar Arteries

Microsurgical anatomy of skull base surgeries for aneurysms of the vertebral and basilar artery were studied using 3 cadavers treated by arterial and venous injection of the mixture of silicon with dye and barium sulfate. The suboccipital and lateral suboccipital approach (LSOA) are useful for VA-PICA and VA union aneurysms that are located laterally. Extradural resection of the jugular tubercle is necessary for approach to midline VA aneurysms. For this procedure, an emissary vein in the condylar fossa is a key anatomical landmark. For lower BA trunk aneurysms, the presigmoid retrolabyrinthine approach (PRA) via the Trautmanns triangular space is useful. This approach, however, does not permit enough working space to access aneurysms between Vth, VIIth—VIIIth and XIth nerves. Additional division of the sigmoid sinus, which might be risky in some patients, and cerebellar tentorium to PRA, namely the retrolabyrinthine transsigmoid approach and combined supraand infratentorial approach permit more space. The (subtemporal) transpetrosal approach might have some problems of a narrow working space (even with a severe retraction of the temporal lobe) and of a difficult exposure of the proximal parent artery. The petrosal approach (PA), which consists of PRA and division of the tentorium and superior petrosal sinus, permits both the subtemporal and suboccipital routes with a minimal brain retraction. PA or the combined approach of (L)SOA and PA might be useful for BA trunk and midline VA aneurysms such as our case, in which multidirectional viewing was allowed through a working space large enough for the aneurysmal clipping and observation of the distal VA or BA behind an aneurysm.