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Yasuhiro Yonekawa

Publications and source records attributed to Yasuhiro Yonekawa.

At least 19 recordsLinked to original sources
PubMed2006

Magnetic iron compounds in the human brain: a comparison of tumour and hippocampal tissue.

Iron is a central element in the metabolism of normal and malignant cells. Abnormalities in iron and ferritin expression have been observed in many types of cancer. Interest in characterizing iron compounds in the human brain has increased due to advances in determining a relationship between excess iron accumulation and neurological and neurodegenerative diseases. In this work, four different magnetic methods have been employed to characterize the iron phases and magnetic properties of brain tumour (meningiomas) tissues and non-tumour hippocampal tissues. Four main magnetic components can be distinguished: the diamagnetic matrix, nearly paramagnetic blood, antiferromagnetic ferrihydrite cores of ferritin and ferrimagnetic magnetite and/or maghemite. For the first time, open hysteresis loops have been observed on human brain tissue at room temperature. The hysteresis properties indicate the presence of magnetite and/or maghemite particles that exhibit stable single-domain (SD) behaviour at room temperature. A significantly higher concentration of magnetically ordered magnetite and/or maghemite and a higher estimated concentration of heme iron was found in the meningioma samples. First-order reversal curve diagrams on meningioma tissue further show that the stable SD particles are magnetostatically interacting, implying high-local concentrations (clustering) of these particles in brain tumours. These findings suggest that brain tumour tissue contains an elevated amount of remanent iron oxide phases.

Brain Neoplasms↗
PubMed2006

Altered expression of alpha3-containing GABAA receptors in the neocortex of patients with focal epilepsy.

Impaired transmission in GABAergic circuits is thought to contribute to the pathogenesis of epilepsy. Although it is well established that major reorganization of GABA(A) receptor subtypes occurs in the hippocampus of patients with medically refractory temporal lobe epilepsy (TLE), it is unclear whether this disorder is also associated with alterations in GABA(A) receptor subtypes in the neocortex. Here we have investigated immunohistochemically the subunit composition and neocortical distribution of three major GABA(A) receptor subtypes using antibodies specifically recognizing the subunits alpha1, alpha2, alpha3, beta2/3 and gamma2. Cortical tissue was obtained at surgery from patients with TLE and hippocampal sclerosis (HS; n = 9), TLE associated with neocortical lesions (non-HS; n = 12) and frontal lobe epilepsy (FLE; n = 5), with post-mortem samples serving as controls (n = 4). A distinct laminar and neuronal expression pattern of the alpha-subunit variants was found across the neocortical regions examined in the temporal and frontal lobes in both control and patient tissue samples. In the five patients with FLE, GABA(A) receptor subunit staining was unchanged as compared to controls. In patients with TLE we observed a marked decrease in alpha3-subunit staining in the superficial neocortical layers (I-III), but no change in the deep layers (V and VI) or in the expression pattern of the alpha1 and alpha2-subunits. Reduced expression in alpha3-containing GABA(A) receptors was detected in six out of nine patients of the HS group and four out of twelve patients of the non-HS group. Histopathological changes were present in eight out of the ten patients with decreased alpha3-subunit staining. The selective reduction in alpha3-containing GABA(A) receptors was confirmed using semiquantitative measurements of optical density (OD). The specific changes unique to alpha3-subunit expression in the superficial neocortical layers of patients with TLE suggest that this subtype is of particular significance in the reorganization of cortical GABAergic systems in focal epilepsy.

Adolescent↗
PubMed2006

Surgical management of tuberculum sellae meningioma: role of selective extradural anterior clinoidectomy.

A retrospective analysis of 32 patients with tuberculum sellae meningiomas who underwent surgery via a unilateral pterional approach was performed. A selective extradural anterior clinoidectomy (SEAC) technique was added in 20 patients. All patients had visual dysfunction preoperatively. Macroscopically complete removal with Simpson grade II was performed in 28 patients (87.5%). The postoperative visual function improved in 25 (78.1%), did not change in 3 (9.4%), and worsened in 4 patients (12.5%). The SEAC technique was effective, especially for removal of the tumour extending into the sellae/pituitary stalk (9 patients), the optic canal (4 patients) and hypothalamus (4 patients) with preservation of the visual and endocrinological function. These results were superior to those of surgery without SEAC technique. This technique is therefore recommended for complete resection of the tuberculum sellae meningiomas extending to the surrounding anatomical structures as the SEAC procedure reduces the risk of intraoperative optic nerve injury considerably.

Adolescent↗
PubMed2006

Genetic alterations in primary glioblastomas in Japan.

Current knowledge of genetic alterations in glioblastomas is based largely on genetic analyses of tumors from mainly caucasian patients in the United States and Europe. In the present study, screening for several key genetic alterations was performed on 77 primary (de novo) glioblastomas in Japanese patients. SSCP followed by DNA sequencing revealed TP53 mutations in 16 of 73 (22%) glioblastomas and PTEN mutations in 13 of 63 (21%) cases analyzed. Polymerase chain reaction (PCR) showed EGFR amplification in 25 of 77 (32%) cases and p16 homozygous deletion in 32 of 77 (42%) cases. Quantitative microsatellite analysis revealed LOH 10q in 41 of 59 (69%) glioblastomas. The frequencies of these genetic alterations were similar to those reported for primary glioblastomas at the population level in Switzerland. As previously observed for glioblastomas in Europe, there was a positive association between EGFR amplification and p16 deletion (p=0.009), whereas there was an inverse association between TP53 mutations and p16 deletion (p=0.049) in glioblastomas in Japan. Multivariate analyses showed that radiotherapy was significantly predictive for longer survival of glioblastoma patients (p=0.002). SSCP followed by DNA sequencing of the kinase domain (exons 18-21) of the EGFR gene revealed mutations in 2 ou of 69 (3%) glioblastomas in Japan and in 4 of 81 (5%) glioblastomas in Switzerland. The allele frequencies of polymorphisms at codon 787 CAG/CAA (Gln/Gln) in glioblastomas in Japan were G/G (82.4%), G/A (10.8%), A/A (6.8%), corresponding to G 0.878 versus A 0.122, significantly different from those in glioblastomas in Switzerland: G/G (27.2%), G/A (28.4%), A/A (44.4%), corresponding to G 0.414 versus A 0.586 (p < 0.0001). These results suggest that primary glioblastomas in Japan show genetic alterations similar to those in Switzerland, suggesting a similar molecular basis in caucasians and Asians, despite different genetic backgrounds, including different status of a polymorphism in the EGFR gene.

Adult↗
PubMed2006

Correlation among pathology, genotype, and patient outcomes in glioblastoma.

Glioblastomas are histologically and genetically heterogeneous. We have investigated to what extent histologic features reflect the genetic profile and whether they are predictive of clinical outcome. Key histologic characteristics, including major cell types (small cell, nonsmall cell), other components such as oligodendroglial components, gemistocytes, multinucleated giant cells, as well as necrosis and microvascular proliferation, of 420 cases of glioblastoma within a population-based study (1) were reassessed and correlated with patients' clinical outcome and key genetic alterations. EGFR amplification and p16 homozygous deletion were significantly more frequent in small cell glioblastomas than in nonsmall cell glioblastomas (EGFR, 46% vs 26%, p = 0.0002; p16 39% vs 25%, p = 0.0167). Multivariate analyses with adjustment for age and gender showed that small cell glioblastomas had frequent EGFR amplification and p16 deletion but infrequent PTEN mutations. An oligodendroglial component was detected in 20% of glioblastomas; these patients were significantly younger (54.4 +/- 13.6 vs 59.2 +/- 13.8 years; p = 0.0049) and survived longer (10.3 +/- 8.3 vs 8.2 +/- 8.4 months; p = 0.0647). However, multivariate analyses with adjustment for age and gender did not show the presence of an oligodendroglial component to be predictive of longer survival. After adjustment for age and gender, LOH 1p was associated with longer survival (hazard ratio, 0.7; 95% confidence interval [CI], 0.5-1.0), whereas LOH 10q was associated with shorter survival (hazard ratio, 1.4; 95% CI, 1.0-1.8) of patients with glioblastoma. Glioblastomas containing >or=5% multinucleated giant cells showed more frequent TP53 mutation and infrequent EGFR amplification than those containing <5% multinucleated giant cells (TP53, 45% vs 24%, p = 0.0001; EGFR, 24% vs 42%, p = 0.0005). Vascular proliferation was observed in all glioblastomas, whereas large ischemic and/or pseudopalisading necrosis was observed in 366 of 420 (87%) cases. Glioblastomas with necrosis were associated with older age (59.2 +/- 13.3 vs 51.6 +/- 15.3 years; p = 0.0001) and shorter survival (7.9 +/- 6.8 vs 12.9 +/- 14.2 months; p = 0.0017). Multivariate analyses with adjustment for age and gender confirmed this observation (hazard ratio, 1.5; 95% CI, 1.1-2.0). Multivariate analysis with adjustment for age and gender showed that necrosis was significantly associated with wild-type TP53 and absence of an oligodendroglial component. These results suggest that some histologic features in glioblastomas are associated with specific genetic alterations and with clinical outcome.

Adult↗
PubMed2006

Specialized neurocritical care, severity grade, and outcome of patients with aneurysmal subarachnoid hemorrhage.

INTRODUCTION: To evaluate the impact of specialized neurocritical care on the population admitted to a neurovascular center and on the outcome of patients with severe aneurysmal subarachnoid hemorrhage (aSAH). METHODS: After exclusion of patients treated with endovascular techniques, between 1999 and 2003, 198 patients with aSAH treated with early aneurysm clipping were analysed. In 1999, a new standardized protocol for intensive care treatment was established in the Department of Neurosurgery, University Hospital Zurich. The results were compared to the earlier time period (1993-1994) immediately after introduction of early aneurysm clipping. RESULTS: Out of 198 patients with aSAH, 90 patients (45.5%) suffered from mild aSAH World Federation of Neurosurgical Societies (WFNS) grade 1 and 2, 41 (27.3%) from aSAH WFNS grade 3, 36 (18.2%) from grade 4, and 57 (28.8%) from grade 5. From 1999 to 2003, significantly more patients with severe aSAH WFNS grade 4 and 5 underwent (further) treatment (93 out of 198 patients; 47.0%) compared to the former time-period after introduction of early surgery (23 out of 150 patients; 15.3%) (p < 0.0001). In the early series, 10 out of 23 patients (43.5%) with WFNS 4 recovered with good outcome Glasgow Outcome Score 4 and 5, whereas in the later series 23 out of 36 (63.9%) with WFNS grade 4 survived in a good functional state. Before 1999, all patients with WFNS grade 5 died or survived in a vegetative state. From 1999 to 2003, 20 out of 57 patients (35.1%) with aSAH WFNS grade 5 survived with good outcome. CONCLUSIONS: The availability of extended specialized neurocritical care seems to induce a change within the patient population towards a higher severity grade. Patients with highgrade aSAH might benefit most from highly specialized neurocritical care treatment.

Adult↗
PubMed2006

Correlation between the efferent venous drainage of the tumor and peritumoral edema in intracranial meningiomas: superselective angiographic analysis of 25 cases.

OBJECT: The extent of peritumoral brain edema (PTBE) associated with meningiomas can be highly variable. The authors studied the correlation between the development of efferent venous drainage from the tumor and the degree of PTBE that occurs in intracranial meningiomas. METHODS: Twenty-five patients with 27 intracranial supratentorial meningiomas were investigated to identify the correlation between the efferent venous drainage system of the tumor and peritumoral edema. The overall mean age of the patients was 54 years. Seventeen patients (68%) were female and eight (32%) were male. All patients underwent magnetic resonance imaging and digital subtraction angiography. In each meningioma, superselective angiography of the dominant feeding artery was performed, including the late venous phase to evaluate the development of the tumor's draining vein. An edema index (EI) was introduced to serve as an objective means by which to judge the extent of PTBE. Eleven meningiomas (41%), in which the mean EI was 0.14 +/- 0.10, clearly showed dominant draining veins originating from the tumor itself. In the other 16 meningiomas (59%), superselective angiography demonstrated no efferent venous drainage from the tumor, which could account for this group's mean EI value of 1.49 +/- 1.05 (p < 0.001). CONCLUSIONS: The current results suggest that hypoplasia of the efferent draining vein from the meningioma itself contributes to PTBE formation. The development of an efferent venous system mitigates against the formation of PTBE. Intratumoral venous congestion can be considered the main cause of PTBE in meningiomas.

Adult↗
PubMed2006

[Operative neurosurgery: personal view and historical backgrounds (1). EC-IC bypass].

This series on surgical technique of neurosurgery contains following topics: EC-IC bypass, aneurysm-AVM surgery, surgery of deep seated tumors such as craniopharyngioma, pineal region tumors, surgery of skull base tumors, intramedullary spinal cord tumors, amygdalohippocampectomy and others. They are originating from author's personal point of view based on his experience and are presented with various techniques learnt from my teachers and colleagues from different countries also mentioning related anecdotes and historical backgrounds. In this issue, presented are the topics about training of microsurgical anastomosis in the laboratory along with belonging techniques and instruments, clinical STA-MCA bypass, OA-PCA bypass and interposition graft bypass including "bonnet" bypass.

Animals↗
PubMed2006

[Operative neurosurgery: personal view and historical backgrounds (2) acoustic neurinoma].

Microsurgical removal of acoustic neurinoma is still one of the challenging topics in neurosurgery in spite of the development of Gamma-knife or radiosurgery, with which small and moderate sized tumors can be treated. Surgical technique necessitates more expertise in dealing with larger tumors. In this report ongoing microsurgical standard technique for removal of acoustic neurinomas of approx. 3 cm (extrameatal) in diameter is presented along with its historical backgrounds and literature review with reported techniques used by experienced neurosurgeons. 1) Standard sitting position with head turned (30) and flexed (20) head, and not semisitting position. 2) retromastoid retrosigmoid osteoplastic craniotomy following a linear incision. Special mention is made on how to manage the air embolism inherent to the sitting position in which the use of fibrin glue to seal the air entrance is presented along with early detection. 3) Intracapsular enucleation after the dural incision and retraction of the biventer lobule with special emphasis on the infrequent anatomical course of the facial and vestibulocochlear nerves on the posterior wall of neurinomas. 4) Localizing the facial nerve and vestibulocochlear nerve at the pontine side, so that decision of preserving or sacrificing the latter in the course of surgery can be made from the viewpoint of hearing preservation and concentrate on facial nerve function. 5) Drilling away of the posterior meatal lip in which sufficient drilling away should be performed to minimize opening of the posterior semicircular canal and that of mastoid cells. Complete sealing of either is necessary to prevent hearing loss or CSF rhinorrhoe. 6) Reduction of remaining tumor-capsule volume by sharp dissection or bipolar cutting, using intraoperative EMG-stimulation which identifies the presence of flattened facial nerve fibers on the capsule. Presence tiny remnant of the tumor capsule attached to the nerve bundles just before the entrance of internal acoustic porus (macroscopical "radical" resection) is considered to be acceptable for better postoperative quality of life. 7) Water tight dural closure and secure sealing of mastoid cells is necessary to prevent CSF rhinorrhoe. 8) Facial muscle EMG monitoring and AEP monitoring are mandaroty to accomplish surgery which enables postoperative good quality of life. 9) Results of 88 cases during last 10 years are: good function (HB I and II) of the facial nerve 90.5% at the time of two years follow-up, 11.5% hearing preservation, 1 mortality due to aspiration pneumonia. CSF rhinorrhoe 10%.

Craniotomy↗
PubMed2005

Distribution and functional activity of P-glycoprotein and multidrug resistance-associated proteins in human brain microvascular endothelial cells in hippocampal sclerosis.

Multidrug resistance protein, also referred as P-glycoprotein (P-gp, MDR1; ABCB1) and multidrug resistance-associated protein (MRP) 1 (ABCC1) and 2 (ABCC2) are, thus far, candidates to cause antiepileptic drug (AED) resistance epilepsy. In this study, we investigated P-gp, MRP1 and MRP2 expression, localization and functional activity on cryosections and isolated human brain-derived microvascular endothelial cells (HBMEC) from epileptic patients (HBMEC-EPI) with hippocampal sclerosis (HS), as compared with HBMEC isolated from normal brain cortex (HBMEC-CTR). We examined the expression and distribution of three transporters, P-gp, MRP1 and MRP2 on two major parts of the resected tissue, the hippocampus and the parahippocampal gyrus (Gph). P-gp showed diffuse expression not only in endothelium but also by parenchymal cells in both the hippocampus and the Gph. MRP1 labeling was observed in parenchymal cells in the Gph. By contrast, MRP2 was mainly found in endothelium of the hippocampus. P-gp and MRP1 expression in the Gph was relatively high in the patient with long-term seizure history. Quantitative RT-PCR analysis of HBMEC revealed that MDR1, MRP1 as well as MRP5 (ABCC5) and MRP6 (ABCC6) were overexpressed in HBMEC-EPI at the mRNA level. HBMEC from both normal and epilepsy groups displayed protein expression of P-gp, whereas MRP1 and MRP2 were seen only in HBMEC-EPI. Accordingly, it is of particular interest that MRP functional activities were observed in HBMEC-EPI, but not in HBMEC-CTR. Our results suggest that complex MDR expression changes not only in the hippocampus but in the Gph may play a role in AED pharmacoresistance in intractable epilepsy patients with mesial temporal lobe epilepsy (MTLE) by altering the permeability of AEDs across the blood-brain barrier (BBB).

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

Growth retardation and bilateral cataracts followed by anaplastic meningioma 23 years after high-dose cranial and whole-body irradiation for acute lymphoblastic leukemia: case report and review of the literature.

We report a case of meningioma diagnosed 23 years after high-dose cranial and whole-body irradiation for the treatment of acute lymphocytic leukemia (ALL). Radiotherapy in this case also caused early radiation injury to the lenses and the pituitary gland, with growth retardation and mineralizing angiopathy. Radiation-induced meningiomas are more commonly malignant, more commonly multiple, and more likely to recur after resection than non-radiation-induced meningiomas. Survivors of childhood ALL treated with high-dose cranial irradiation are at risk both for early radiation injury in radiosensitive organs, such as the lens and pituitary gland, and for the later development of a radiation-induced meningioma.

Adult↗
PubMed2005

Altered expression of immune defense genes in pilocytic astrocytomas.

Pilocytic astrocytoma (WHO grade I) is a circumscribed, slowly growing, benign astrocytoma that most frequently develops in the cerebellar hemispheres and in midline structures and occurs predominantly in childhood and adolescence. In contrast to diffusely infiltrating gliomas in adults (e.g. grade II astrocytomas, oligodendrogliomas), survival of patients with pilocytic astrocytoma is excellent after surgical intervention. To search for potential molecular mechanisms underlying its benign biologic behavior, we compared gene expression profiles of pilocytic astrocytomas (8 cases) with those of normal cerebellum (4 cases), low-grade astrocytomas (WHO grade II; 15 cases), and oligodendrogliomas (WHO grade II; 17 cases) by cDNA array analysis. A number of immune system-related genes such as HLA-DRalpha, HLA-DPB1, HLA-DQB1, IgG3, IgGK, FCER1G, A2M, FCRN, IFI-56K, and DAP12 were upregulated in pilocytic astrocytomas relative to normal cerebellum, grade II astrocytomas, and oligodendrogliomas. Genes expressed at higher levels in pilocytic astrocytomas than in grade II astrocytomas and oligodendrogliomas include HLA-DRalpha, HLA-DPA1, HLA-DPB1, HLA-DQB1, A2M, TIMP1, TIMP2, CDKN1A, and SOCS3 and those expressed at lower levels include EGFR and PDGFRA. Hierarchical clustering analysis using the entire set of 1176 genes distinguished pilocytic astrocytomas from grade II astrocytomas and oligodendrogliomas. Clustering analysis using selected subgroups of genes based on their molecular functions revealed that immune system-related genes (75 genes) or cell adhesion, migration, and angiogenesis-related genes (69 genes) showed similar power to the entire gene set for separation of pilocytic astrocytomas from diffusely infiltrating low-grade gliomas. Immunohistochemistry revealed that HLA-DRalpha is expressed diffusely in neoplastic cells in pilocytic astrocytomas, whereas in oligodendrogliomas, expression was limited to scattered reactive astrocytes. These results suggest that gene expression profiles of pilocytic astrocytomas differ significantly from those of diffusely infiltrating low-grade gliomas and that their benign biologic behavior may be related to upregulation of immune defense-associated genes.

Adolescent↗
PubMed2005

Awake surgery for glioma resection in eloquent areas--Zurich's experience and review--.

Awake surgery was performed in a series of 21 patients with gliomas in eloquent areas with the use of intraoperative electrical mapping. Gross total removal was performed in 18 patients. There was no operative mortality. Postoperative findings included no change in symptoms and signs in 10 patients, improvement of the preoperative deficit in 11 patients. Four patients had improved Karnofsky performance status (KPS) scores after surgery, 17 patients were stable, and no patient had lower KPS score. Extensive radical resection of gliomas prolongs the overall survival and improves the patient's quality of life. However, surgical resection of gliomas located within the sensorimotor or language areas remains a neurosurgical challenge in reducing eloquent neurological sequelae. Awake surgery with intraoperative functional mapping is a safe approach to maximize the extent of tumor removal and to minimize the resultant neurological deficits in the treatment of glioma involving the eloquent cortex.

Adult↗
PubMed2005

Induction of reactive oxygen intermediates-dependent programmed cell death in human malignant ex vivo glioma cells and inhibition of the vascular endothelial growth factor production by taurolidine.

OBJECT: Taurolidine, a derivative of the amino acid taurin, was recently found to display a potent antineoplastic effect both in vitro and in vivo. The authors therefore initiated studies to assess the potential antineoplastic activity of taurolidine in human glioma cell lines and in ex vivo malignant cell cultures. They also studied the mechanisms that induce cell death and the impact of taurolidine on tumor-derived vascular endothelial growth factor (VEGF) production. METHODS: Cytotoxicity and clonogenic assays were performed using crystal violet staining. In the cytotoxicity assay 100% of glioma cell lines (eight of eight) and 74% of ex vivo glioma cultures (14 of 19) demonstrated sensitivity to taurolidine, with a mean median effective concentration (EC50) of 51 +/- 28 microg/ml and 56 +/- 23 microg/ml, respectively. Colony formation was inhibited by taurolidine, with a mean EC50 of 7 +/- 3 microg/ml for the cell lines and a mean EC50 of 3.5 +/- 1.7 microg/ml for the ex vivo glioma cultures. On observing this high activity of taurolidine in both assays, the authors decided to evaluate its cell death mechanisms. Fragmentation of DNA, externalization of phosphatidylserine, activation of poly(adenosine diphosphate-ribose) polymerase, loss of the mitochondrial membrane potential followed by a release of apoptosis-inducing factor, and typical apoptotic features were found after taurolidine treatment. Cell death was preceded by the generation of reactive O2 intermediates, which was abrogated by N-acetylcysteine but not by benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone. Moreover, taurolidine also induced suppression of VEGF production on the protein and messenger RNA level, as shown by an enzyme-linked immunosorbent assay and by reverse transcription-polymerase chain reaction. CONCLUSIONS: Given all these findings, taurolidine may be a promising new agent in the treatment of malignant gliomas; it displays a combination of antineoplastic and antiangiogenic activities, inducing tumor cell apoptosis and inhibiting tumor-derived VEGF production.

Acetylcysteine↗
PubMed2004

Genetic pathways to glioblastoma: a population-based study.

We conducted a population-based study on glioblastomas in the Canton of Zurich, Switzerland (population, 1.16 million) to determine the frequency of major genetic alterations and their effect on patient survival. Between 1980 and 1994, 715 glioblastomas were diagnosed. The incidence rate per 100,000 population/year, adjusted to the World Standard Population, was 3.32 in males and 2.24 in females. Observed survival rates were 42.4% at 6 months, 17.7% at 1 year, and 3.3% at 2 years. For all of the age groups, younger patients survived significantly longer, ranging from a median of 8.8 months (<50 years) to 1.6 months (>80 years). Loss of heterozygosity (LOH) 10q was the most frequent genetic alteration (69%), followed by EGFR amplification (34%), TP53 mutations (31%), p16(INK4a) deletion (31%), and PTEN mutations (24%). LOH 10q occurred in association with any of the other genetic alterations and was predictive of shorter survival. Primary (de novo) glioblastomas prevailed (95%), whereas secondary glioblastomas that progressed from low-grade or anaplastic gliomas were rare (5%). Secondary glioblastomas were characterized by frequent LOH 10q (63%) and TP53 mutations (65%). Of the TP53 mutations in secondary glioblastomas, 57% were in hotspot codons 248 and 273, whereas in primary glioblastomas, mutations were more equally distributed. G:C-->A:T mutations at CpG sites were more frequent in secondary than primary glioblastomas (56% versus 30%; P = 0.0208). This suggests that the acquisition of TP53 mutations in these glioblastoma subtypes occurs through different mechanisms.

Adult↗
PubMed2004

Gene expression profiling and subgroup identification of oligodendrogliomas.

The histological diagnosis of low-grade astrocytomas and oligodendrogliomas (WHO grade II) is often challenging, particularly in cases that show both astrocytic and oligodendroglial differentiation. We carried out gene expression profiling on 17 oligodendrogliomas (93% with LOH 1p and/or 19q) and 15 low-grade astrocytomas (71% with a TP53 mutation), using a cDNA array containing 1176 cancer-related genes. In oligodendrogliomas, 40 genes showed on average higher expression (at least a two-fold increase) than in astrocytomas, including DES, TDGF1, TGF-beta, GABA-BR1A, Histone H4, CDKN1A, PCDH43, Rho7 and Jun-D, while 39 genes were expressed at lower levels (at least a two-fold decrease), including JNK2, ITGB4, JNK3A2, RhoC, IFI-56K, AAD14 and EGFR. Immunohistochemistry revealed nuclear staining of Jun-D in oligodendrogliomas, in contrast to the immunoreactivity of cytoplasm and cell processes in low-grade astrocytomas. Partial least-squares analysis of the 79 genes at least two-fold differentially expressed between oligodendrogliomas and low-grade astrocytomas demonstrated perfect separation of oligodendrogliomas from low-grade astrocytomas and normal cerebral white matter. Clustering analysis based on the entire gene set divided the 17 subjects with oligodendrogliomas into two subgroups with significantly different survival (log-rank test, P=0.0305; survival to 5-years, 80 vs 0%, P=0.048). These results demonstrate that oligodendrogliomas and low-grade astrocytomas differ in their gene expression profiles, and that there are subgroups of oligodendroglioma with distinct expression profiles related to clinical outcome.

Adult↗
PubMed2004

Decompressive craniotomy after middle cerebral artery infarction. Retrospective analysis of patients treated in three centres in Switzerland.

QUESTIONS UNDER STUDY / PRINCIPLES: Several studies have reported an improved outcome in patients presenting with complete middle cerebral artery (MCA) infarction treated by decompressive hemicraniectomy. Although this palliative treatment form has gained popularity in Switzerland since 2000, the results of these series have not been reported. The aim of this study is, firstly, to report factors influencing the outcome of our patients, in order to create awareness of the indications and decision-making processes in our departments, and, secondly, to analyse therapeutic strategies which are open to improvement and standardisation. METHODS: This retrospective study included a total of 28 patients (age 51 +/- 12 years) who underwent decompressive craniectomy after MCA between January 2000 and May 2002 at the Departments of Neurosurgery of Aarau (n: 6), Bern (n: 10), and Zurich (n: 12). Demographic characteristics included preoperative clinical condition (NIHSS and GCS), timing of surgery, cause, location, and extension of infarction. Additionally, the time delay from the onset of symptoms to surgery and preoperative signs of herniation and their relation to final outcome was analysed. The final outcome was assessed in terms of mortality and scores such as modified Rankin scale and Barthel index. RESULTS: The preoperative clinical condition according to NIHSS was 20.2 +/- 4.7 and GCS was 10.6 +/- 3.6. The mean time in hours to surgery after onset of symptoms was 35 +/- 24. Twelve patients (42.8%) underwent "early" surgery (within 24 hours) and 21 (75%) suffered non-dominant stroke. The follow-up period was 22 +/- 13 months and 17% of the patients died within this period. Outcome did not differ significantly between institutions. The overall mean Barthel index was 47 +/- 25 and modified Rankin scale was 4 +/- 1.3. CONCLUSIONS: The outcome in patients undergoing decompressive craniectomy after MCA infarction in Switzerland is less favourable than in other series recently reported. Less favourable preoperative clinical condition, inclusion of dominant hemispheric infarction, poorly defined protocols and late involvement of neurosurgeons on these patients' admission may explain the results.

Adult↗