Direct clipping of a large basilar trunk aneurysm via the posterior petrosal (extended retrolabyrinthine presigmoid) approach--case report.

A 53-year-old female presented with an unruptured, large basilar trunk aneurysm manifesting only as headache with no neurological deficits, including absence of cranial nerve dysfunction. Cerebral angiography disclosed a large aneurysm with a wide neck arising from the midbasilar artery. We treated the aneurysm surgically via the posterior petrosal approach.

Ventral T-1 neurinoma removed via hemilaminectomy without costotransversectomy--case report.

A 39-year-old male presented with a spinal neurinoma originating from the T-1 anterior root and located ventral to the spinal cord. The tumor was removed by hemilaminectomy with only partial facetectomy without costotransversectomy. No stabilization was necessary, and no complications secondary to surgery occurred.

Increased telomerase activity and absence of p53 mutation in oligoastrocytomas induced by N-ethyl-N-nitrosourea in rats.

The question of whether the changes in telomerase activity and/or the alteration of the p53 gene are involved in the development of oligo-astrocytomas induced by N-ethyl-N-nitrosourea (ENU) in rats was addressed. Telomerase activity levels of oligo-astrocytomas, including early neoplastic lesions, were significantly increased as compared to the normal controls, correlating with the degree of malignancy. In contrast, no mutations of p53 exons 5-7 were found in early neoplastic lesions or oligo-astrocytomas.

Analyses of human gliomas by restriction landmark genomic scanning.

The 16 primary gliomas were examined for changes in genomic DNA using a recently developed 2-dimensional gel electrophoresis method called restriction landmark genomic scanning (RLGS). This approach allows detection of DNA amplification, deletion, methylation and potentially other genetic rearrangements represented as decreases and increases in spot/fragment intensity on an autoradiogram. Approximately 2,000 landmark sites in tumor DNA were compared with those of DNA isolated from normal brain tissues.

Genomic alterations in human glioma cell lines detected by restriction landmark genomic scanning.

Restriction landmark genomic scanning (RLGS) is a 2-dimensional gel analysis capable of detecting amplifications, deletions and rearrangements in genomic DNA. Using RLGS, we examined genomic DNA from each of 6 human-derived malignant glioma cell lines and from normal brain tissue samples. RLGS allows us to screen genomic DNAs as approximately 2,000 landmark sites in one procedure without any polymorphic markers.

Shortened telomere length and increased telomerase activity in hamster pancreatic duct adenocarcinomas and cell lines.

Recently, shortened telomere length and increased telomerase activity have been demonstrated in various human cancers. In the study reported here, we ascertained whether gene changes are characteristic of pancreatic cancers. Hamster duct carcinomas and cell lines were investigated by Southern blot analysis for telomere restriction fragment (TRF) length and by the telomeric repeat amplification protocol (TRAP) assay for telomerase activity.

p53 mutation and absence of mdm2 amplification and Ki-ras mutation in 4-hydroxyamino quinoline 1-oxide induced transplantable osteosarcomas in rats.

Previously, we reported the establishment of two transplantable osteosarcomas, one induced by local application of a carcinogen, 4-hydroxyamino quinoline 1-oxide(4-HAQO), and another which developed spontaneously in rats, and their subdivision into four lines with high and low metastatic potential to the lung. In the present study, mutations of p53 and Ki-ras genes were investigated by PCR and SSCP followed by direct sequencing, and the amplification of the mdm2 gene was assessed by Southern blot analysis. Mutations of p53 in exon 7 were detected in 4-HAQO-induced transplantable osteosarcomas, but not their spontaneous counterparts, irrespective of the metastatic potentials.

Genomic alterations of human gliomas detected by restriction landmark genomic scanning.

Alterations of genomic DNA in eight primary astrocytic tumors and two glioma cell lines were examined using a recently developed two-dimensional gel electrophoresis method called restriction landmark genomic scanning (RLGS). RLGS allows us to detect amplifications, deletions, and methylation in genomic DNA in one procedure without requiring any polymorphic markers. Approximately 2000 spots (landmark sites) in tumor specimens were compared with those in normal brain tissue.

Infrequent Ki-ras and an absence of p53 mutations in hepatocellular carcinomas induced by a choline deficient L-amino acid defined diet in rats.

Mutations of Ki-ras and p53 genes in hepatocellular carcinomas (HCCs) induced by the choline deficient L-amino acid defined (CDAA) diet in rats were investigated by polymerase chain reaction (PCR), single strand conformation polymorphism (SSCP) analysis followed by direct sequencing. Male Fischer 344 rats, 6 weeks old, were continuously given a CDAA diet for 70 weeks and then sacrificed. Macroscopically detectable nodules which were histologically confirmed to be well-differentiated HCCs were dissected free from the surrounding tissue and subjected to gene mutation analysis along with samples of non-tumor areas.

Increased telomerase activity in hyperplastic nodules and hepatocellular carcinomas induced by a choline-deficient L-amino acid-defined diet in rats.

Activation of telomerase has been reported in several human cancers, including hepatocellular carcinomas (HCCs). We investigated telomerase activity during hepatocarcinogenesis induced by a choline-deficient L-amino acid-defined (CDAA) diet in rats. Male F344 rats were given a CDAA diet or a choline-supplemented L-amino acid-defined (CSAA) diet from 6 weeks of age for 75 weeks, and subgroups were killed 10 weeks, 50 weeks and 75 weeks after the beginning of the experiment.

Enhancement of N-nitrosodiethylamine-initiated hepatocarcinogenesis caused by a colchicine-induced cell cycle disturbance in partially hepatectomized rats.

The effects of a colchicine-induced M-phase block of regeneration after partial hepatectomy on early-stage liver carcinogenesis were studied in rats. When administered 1 or 3 days after N-diethylnitrosamine initiation and partial hepatectomy, colchicine increased the mitotic index of regenerating hepatocytes at days 4-6 without evidence of liver cell necrosis. When the protocol was combined with a selection procedure (E.

Immunohistochemical detection of CDKN2, retinoblastoma and p53 gene products in primary astrocytic tumors.

The expressions of p16(INK4), retinoblastoma (RB) and p53 protein were immunohistochemically examined in 70 primary astrocytic tumors. In 58 patients with high grade astrocytoma (18 anaplastic astrocytomas and 40 glioblastomas), 30 (51.1%) and 15 (25.

Shortened telomere length in hepatocellular carcinomas and corresponding background liver tissues of patients infected with hepatitis virus.

The telomere length in 20 surgically resected human hepatocellular carcinomas (HCCs) and adjacent non-cancerous livers with hepatitis virus infection were investigated. All the HCC samples examined demonstrated shorter telomere length than the corresponding non-cancerous liver tissues, the respective average values being 5.4 kbp and 8.

Telomere changes in human hepatocellular carcinomas and hepatitis virus infected noncancerous livers.

Background: Telomeres, at the ends of eukaryotic chromosomes, are defined functionally as necessary for chromosome stability. Chromosome instability induced in part by loss of telomeric DNA has been considered to play a significant role in the development of human cancers. However, little is known about the status of telomeres per se during human hepatocellular carcinoma (HCC) development.

Disturbance of the cell cycle with colchicine enhances the growth advantage of diethylnitrosamine-initiated hepatocytes in rats.

The effect of cell cycle disturbance due to colchicine on the induction of enzyme-altered foci during liver regeneration in rats was studied. For initiation, diethylnitrosamine (DEN) at a dose of 10 mg/kg was injected intraperitoneally and partial hepatectomy (PH) was performed 4 h thereafter. Colchicine at doses of 0, 0.

Anastomosis of occipital artery to posterior cerebral artery with interposition of superficial temporal artery using occipital interhemispheric transtentorial approach: case report.

Background: Superficial temporal artery (STA)-superior cerebellar artery (SCA) anastomosis, and STA-posterior cerebral artery (PCA) anastomosis are considered suitable as surgical procedures for the treatment of patients with significant stenosis or occlusion in the rostral portion of the basilar artery and patients with significant stenosis or occlusion of the posterior cerebral artery, respectively. However, several authors have reported frequent and serious complications of these surgical procedures, including temporal lobe retraction edema and hematoma. In this study, we introduce a new surgical revascularization using an occipital interhemispheric transtentorial approach for the treatment of severe stenosis of the rostral portion of the basilar artery.