bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular cytogenetic analysis of medulloblastomas and supratentorial primitive neuroectodermal tumors by using conventional banding, comparative genomic hybridization, and spectral karyotyping
Authors: Bayani Jane , Zielenska Maria , Marrano Paula , Ng Yim Kwan , Taylor Michael D. , Jay Venita , Rutka James T. , Squire Jeremy A. 
Published: May 2009

Object. Medulloblastomas and related primitive neuroectodermal tumors (PNETs) of the central nervous system are malignant, invasive embryonal tumors with predominantly neuronal differentiation that comprise 20% of pediatric brain tumors. Cytogenetic analysis has shown that alterations in chromosome 17, particularly the loss of 17p and the formation of isochromosome 17q, as well as the gain of chromosome 7 are the most common changes among this group of tumors. Comparative genomic hybridization (CGH) studies have largely confirmed these cytogenetic findings and have also identified novel regions of gain, loss, and amplification. The advent of more sophisticated multicolored fluorescence in situ hybridization (FISH) procedures such as spectral karyotyping (SKY) now permits complete recognition of all aberrations including extremely complex rearrangements. The authors report a retrospective analysis of 19 medulloblastoma and five PNET cases studied using combinations of classic banding analysis, FISH, CGH, and SKY to examine comprehensively the chromosomal aberrations present in this tumor group and to attempt to identify common structural rearrangement(s).Methods. The CGH data demonstrate gains of chromosomes 17q and 7 in 60% of the tumors studied, which confirms data reported in the current literature. However, the authors have also combined the results of all three molecular cytogenetic assays (Giemsa banding, CGH, and SKY) to reveal the frequency of chromosomal rearrangement (gained, lost, or involved in structural rearrangement).Conclusions. The combined results indicate that chromosomes 7 and 17 are the most frequently rearranged chromosomes (10.1% and 8.9%, respectively, in all rearrangements detected). Furthermore, chromosomes 3 (7.8%), 14 (7%), 10 (6.7%), and 22 (6.5%) were also found to be frequently rearranged, followed by chromosomes 6 (6.5%), 13 (6.2%), and 18 (6.2%). Eight (33%) of 24 tumors exhibited high-level gains or gene amplification. Amplification of MYCN was identified in four tumors, whereas amplification of MYCC was identified in one tumor. One tumor exhibited a high-level gain of chromosome 9p. Additionally, desmoplastic medulloblastomas and large-cell medulloblastomas exhibited higher karyotype heterogeneity, amplification, and aneusomy than classic medulloblastomas.
Hypoxia in a human intracerebral glioma model
Authors: Bernsen Hans J. J. A. , Rijken Paul F. J. W. , Peters Hans , Raleigh James A. , Jeuken Judith W. M. , Wesseling Pieter , van der Kogel Albert J. 
Published: May 2009

Object. The development of hypoxia in human gliomas is closely related to functional vasculature and the presence of hypoxia has important biological and therapeutic consequences. Assessment of hypoxia is necessary to understand its role in treatment response and to evaluate treatment strategies to improve tumor oxygenation. In this study, the authors report findings of their analysis of the degree of hypoxia in relation to other vascular parameters in a human intracerebral glioma xenograft.Methods. In sections of tumor, hypoxic regions were identified immunohistochemically by using the hypoxic marker pimonidazole. The S-phase marker bromodeoxyuridine was used to detect cell proliferation, and the perfusion marker Hoechst 33342 was used to delineate perfused vessels. Vascular structures were stained with an endothelial marker.Hypoxic tumor regions were clearly present in this human intracerebral glioma model. Hypoxic areas were usually found in nonperfused regions, whereas tumor cell proliferation was especially marked in perfused tumor areas. Furthermore, by using in situ hybridization the authors identified infiltrating tumor cells in the normal brain. This feature is often observed in gliomas in patients.Conclusions. This model is a representative human glioma model that provides the researcher with the opportunity to analyze the relationship between the degree of hypoxia and vascular parameters, as well as to examine the effects of treatments aimed at modification of the oxygenation status of a tumor.
Upregulation of rho A and rho kinase messenger RNAs in the basilar artery of a rat model of subarachnoid hemorrhage
Authors: Miyagi Yasushi , Carpenter Robin C. , Meguro Toshinari , Parent Andrew D. , Zhang John H. 
Published: May 2009

Object. Rho A, a small guanosine triphosphate—binding protein, and rho kinases have been suggested to play an important role in the agonist-induced myofilament Ca++ sensitization and cytoskeletal organization of smooth-muscle cells. To discover their possible roles in the prolonged contraction seen in cerebral vasospasm, the authors investigated the messenger (m)RNA expressions of rho A and rho-associated kinases α and β in the basilar artery (BA) of a rat double cisternal blood—injection model.Methods. An experimental subarachnoid hemorrhage (SAH) was achieved in rats by twice injecting autologous arterial blood into the cisterna magna of each animal. The mRNAs for rho A and rho-associated kinases α and β of the rat BA were analyzed using reverse transcription—polymerase chain reaction (RT-PCR). The cisternal blood injection induced a marked corrugation of elastic lamina and contraction of smooth-muscle cells observed with the aid of light and transmission electron microscopy in the rat BA on Days 3, 5, and 7. Results of the RT-PCR revealed that mRNAs for rho A and rho kinases α and β were expressed in the rat BA and that they were significantly upregulated and reached their peaks on Day 5.Conclusions. The mRNA upregulation of these proteins indicates that activation of rho A/rho kinase—related signal transduction pathways is involved in the development of long-lasting contraction of cerebral arteries after SAH.
Biographical sketch of Kenneth G. McKenzie (1892–1964)
Authors: Morley Thomas P. 
Published: May 2009

✓ This article is an expanded version of the opening address Dr. Morley delivered at a University of Toronto symposium, “Seventy-Five Years of Neurosurgery in Canada,” celebrating the 75th Anniversary of the appointment of Kenneth G. McKenzie, Canada's first career neurosurgeon, to the University of Toronto and the Toronto General Hospital in 1923.Kenneth G. McKenzie (1892–1964) was the first surgeon in Canada to limit his practice to neurosurgery. This article contains a brief biographical study of the man, his upbringing, and management of his professional life at Toronto General Hospital. Some of his published neurosurgical articles are also reviewed.
Natural history of the neck remnant of a cerebral aneurysm treated with the Guglielmi detachable coil system
Authors: Hayakawa Motoharu , Murayama Yuichi , Duckwiler Gary R. , Gobin Y. Pierre , Guglielmi Guido , Viñuela Fernando 
Published: May 2009

Object. The long-term durability of Guglielmi detachable coil (GDC) embolization of cerebral aneurysms is still unknown. The purpose of this study was to evaluate the anatomical evolution of neck remnants in aneurysms treated with GDCs.Methods. Of 455 aneurysms treated with GDCs from 1990 to 1998 at the University of California at Los Angeles Medical Center, 178 aneurysms (39%) had residual necks postembolization. Long-term follow-up angiograms were obtained in 73 of these aneurysms in 71 patients. The mean duration of angiographic follow up was 17.3 months. Twenty-four of the aneurysms were small with small necks, 24 were small with wide necks, 15 were large, and 10 were giant aneurysms.In small aneurysms with small necks, postembolization angiography revealed 12 aneurysms (50%) with progressive thrombosis, eight (33%) unchanged, and four (17%) with recanalization. In small aneurysms with wide necks, six (25%) had progressive thrombosis, eight (33%) remained unchanged, and 10 (42%) had recanalization. In large aneurysms, two (13%) were unchanged and 13 (87%) had recanalization. Of the giant aneurysms only one (10%) remained unchanged and nine (90%) had recanalization. Overall, 18 aneurysms (25%) exhibited progressive thrombosis, 19 (26%) remained unchanged, and 36 (49%) displayed recanalization on follow-up angiography. During the last 2 years of the study, the recanalization rate decreased and a higher rate of progressive thrombosis was noted in aneurysms with small necks. These positive changes are related to important new technical developments.Conclusions. Treatment with GDCs appears to be effective and the results permanent in most small aneurysms with small necks. However, there are important technical limitations in the current GDC technology that prevent recanalization in wide-necked or large or giant aneurysms.
Impact of Guglielmi detachable coils on outcomes of patients with intracranial aneurysms treated by a multidisciplinary team at a single institution
Authors: Sturaitis Mary K. , Rinne Jaakko , Chaloupka John C. , Kaynar Mehmet , Lin Zhenqiu , Awad Issam A. 
Published: May 2009

Object. The goal of this study was to investigate the impact of the introduction of the Guglielmi detachable coil (GDC) therapeutic option on the overall management outcome of intracranial aneurysms. The authors accomplished this by assessing patient morbidity and mortality, inflation-adjusted hospital charges, lengths of stay in the hospital and the intensive care unit (ICU), and treatment efficacy.Methods. The authors conducted a retrospective analysis of consecutive cases of intracranial intradural aneurysms managed by a single multidisciplinary neurovascular team at a tertiary care, academic referral center during the 24 months preceding the introduction of the GDC procedure (Group I or pre-GDC era, 77 patients) and during the first 24 months after its introduction (Group II or GDC era, 99 patients).Treatment with GDCs was considered for cases of higher clinical grade or poor surgical risk, or in response to patient preference (27 [27%] of 99 patients in Group II). Host and lesion parameters in our cohort were validated against outcome parameters by using univariate and multivariate analyses. The pre-GDC and GDC subgroups of patients were comparable for major disease severity parameters (patient age, lesion location, clinical grade, and hemorrhage severity). There was no significant difference in clinical outcome at 6 months, infarcts on computerized tomography scanning, or aneurysm obliteration rates before and after introduction of GDC treatment. Decreasing trends in duration of hospital and ICU stay and in inflation-adjusted hospital charges occurred well before and thus were unrelated to the introduction of the GDC therapeutic option.Conclusions. The results of this study do not demonstrate any significant impact of integration of the GDC modality on clinical outcome, mortality, morbidity, or effectiveness of treatment. Ongoing improvements in hospital charges and length of hospital stay appeared unrelated to the introduction of the GDC option.
Change in circulating blood volume following craniotomy
Authors: Hirasawa Kenichi , Kasuya Hidetoshi , Hori Tomokatsu 
Published: May 2009

Object. The importance of monitoring circulating blood volume (CBV) during perioperative management is widely recognized in critically ill patients. The purpose of this study was to investigate the change in CBV following craniotomy by using indocyanine-green pulse spectrophotometry.Methods. Circulating blood volume and plasma hormones related to stress and fluid regulation were measured five times: preoperatively, immediately postoperatively, and 1, 2, and 7 days after craniotomy was performed in 17 patients with a brain tumor or an unruptured aneurysm.The mean value of CBV preoperatively was 82 ml/kg, which decreased to 64 ml/kg (78%) immediately postoperatively and gradually recovered to 82 ml/kg on Day 7 postsurgery (p = 0.0069). The mean values of adrenaline, noradrenaline, arginine vasopressin, renin, and aldosterone were highest immediately postoperatively. The mean intraoperative balances of water and sodium were 1090 ml and 113 mEq, respectively. Partial correlation coefficients of CBV to noradrenaline and serum sodium during the entire study were −0.430 (p = 0.0036) and 0.418 (p = 0.0048), respectively.Conclusions. Attention should be paid to decreased CBV following craniotomy, which is caused by the shift of fluid to interstitial spaces due to surgical stress. Hypovolemia can be suspected from a postoperative decrease in serum sodium.
Role of hydrodynamic processes in the pathogenesis of peritumoral brain edema in meningiomas
Authors: Bitzer Michael , Nägele Thomas , Geist-Barth Beverly , Klose Uwe , Grönewäller Eckardt , Morgalla Matthias , Heiss Eckart , Voigt Karsten 
Published: May 2009

Object. In a prospective study, 28 patients with 32 intracranial meningiomas were examined to determine the role of hydrodynamic interaction between tumor and surrounding brain tissue in the pathogenesis of peritumoral brain edema.Methods. Gadolinium—diethylenetriamine pentaacetic acid (Gd-DPTA), an extracellular contrast agent used for routine clinical imaging, remains strictly extracellular without crossing an intact blood—brain barrier. Therefore, it is well suited for investigations of hydrodynamic extracellular mechanisms in the development of brain edema. Spin-echo T1-weighted magnetic resonance images were acquired before and after intravenous administration of 0.2 mmol/kg Gd-DPTA. Additional T1-weighted imaging was performed 0.6, 3.5, and 6.5 hours later. No significant Gd-DPTA diffused from tumor into peritumoral brain tissue in 12 meningiomas without surrounding brain edema. In contrast, in 17 of 20 meningiomas with surrounding edema, contrast agent in peritumoral brain tissue was detectable after 3.5 hours and 6.5 hours. In three of 20 meningiomas with minimum surrounding edema (< 5 cm3), contrast agent effusion was absent. After 3.5 hours and 6.5 hours strong correlations of edema volume and the maximum distance of contrast spread from the tumor margin into adjacent brain parenchyma (r = 0.84 and r = 0.87, respectively, p < 0.0001) indicated faster effusion in larger areas of edema.Conclusions. The results of this study show that significant contrast agent effusion from the extracellular space of the tumor into the interstitium of the peritumoral brain tissue is only found in meningiomas with surrounding edema. This supports the hypothesis that hydrodynamic processes play an essential role in the pathogenesis of peritumoral brain edema in meningiomas.
Prognostic factors in intracranial ependymomas in children
Authors: Figarella-Branger Dominique , Civatte Muriel , Bouvier-Labit Corine , Gouvernet Joany , Gambarelli Danielle , Gentet Jean-Claude , Lena Gabriel , Choux Maurice , Pellissier J. F. 
Published: May 2009

Object. The occurrence of intracranial ependymomas in children is relatively infrequent, and their prognostic factors are still controversial, especially regarding histological composition.Methods. A retrospective study was conducted of 37 children treated during the last 20 years for intracranial ependymomas at the Hôpital de la Timone. Both univariate and multivariate statistical analyses were performed to assess the prognostic relevance of patient age and sex, extent of tumor removal, location of the tumor (supratentorial compared with infratentorial, median compared with lateral), tumor histological composition, and adjuvant therapies in affecting the 5-year progression-free survival (PFS) rate and overall survival (OS) rate. The following histopathological features, either alone or in combination, were analyzed: endothelial proliferation, necrosis, loss of differentiating structures (present compared with absent), the number of mitotic figures per 10 hpf, and cellularity (number of nuclei/5 hpf). In addition, immunohistochemical detection of Ki-67 antigen was performed and the Ki-67 labeling index (LI) evaluated in all cases.The 5-year OS and PFS rates were 45% and 25%, respectively (median follow up 34 months). Four patients died of disease without remission (median 163 days) and disease in 21 patients relapsed: 18 in situ and three both in situ and distantly. On univariate analysis total surgical resection and median infratentorial location were associated with a better outcome (p < 0.002) for both OS and PFS. Loss of differentiating structures was associated with poor prognosis (p < 0.008) and the combination of necrosis, endothelial proliferation, and mitotic index greater than 5 was also a negative predictive factor for both OS (p < 0.002) and PFS (p = 0.02). The PFS time was shorter in patients younger than 4 years of age and in patients in whom a Ki-67 LI greater than 1 was found (p = 0.03 and 0.006, respectively). Adjuvant radiotherapy and chemotherapy were not relevant to prognosis. Moreover, among the 15 patients in whom total excision was achieved, OS was better in those who did not receive adjuvant therapies. In contrast, adjuvant therapies significantly enhanced PFS time in patients in whom tumor excision was incomplete.Conclusions. This study and analysis of the literature further highlight that total tumor removal is the treatment of choice for ependymomas in children. Postoperative measurement of residual tumor is required, especially because a subgroup of patients might be treated by surgery alone. Median infratentorial ependymomas have to be distinguished from the lateral type. Appropriate and reproducible histological parameters and Ki-67 LI are of interest as predictors of outcome.
Telomerase activity in primary and secondary glioblastomas multiforme as a novel molecular tumor marker
Authors: Harada Kunyu , Kurisu Kaoru , Tahara Hidetoshi , Tahara Eiji , Ide Toshinori , Tahara Eiichi 
Published: May 2009

Object. Telomerase activity is responsible for cell immortality. To examine the role of telomerase in the carcinogenesis of human glioblastomas multiforme (GBMs), the authors studied telomerase activity, telomerase component expression, and telomere lengths in 42 GBM samples.Methods. In all samples, EGFR and MDM2 amplifications and overexpressions were examined using Southern and Northern blot analyses. The p53 mutation was analyzed using polymerase chain reaction—single strand conformational polymorphism and by direct sequence analysis. Specimens of tissues were immunostained with p53, EGFR, and MDM2 antibodies. Allelic loss on chromosomes 17p and 10 was assessed by loss of heterozygosity (LOH) assays. Telomerase activity, expression of its components (human telomerase reverse transcriptase [hTERT], human telomerase RNA component [hTERC], and telomerase-associated protein [TEP1]), and telomere lengths were analyzed using the telomeric repeat amplification protocol (TRAP)—hybridization protection assay, reverse transcription—polymerase chain reaction, and Southern blot analysis. According to the results of assessments of EGFR and MDM2 amplifications, p53 mutation, LOHs in chromosomes 17p and 10, and the clinical course of the disease, the 42 samples were classified into 22 primary and 20 secondary glioblastomas.Twenty-six (61.9%) of all 42 samples demonstrated detectable telomerase activity during the TRAP assay. Secondary GBMs displayed significantly higher levels of telomerase activity and hTERT expression than primary GBMs. Tumors with a p53 gene mutation demonstrated significantly higher telomerase activity than those without a p53 mutation. Four samples with a codon 175 mutation demonstrated an exceptionally high amount of telomerase activity. In secondary GBMs, the increase in telomerase activity and the hTERT expression level correlated with the increased frequency of p53 mutations. There was no significant difference in telomere length between primary and secondary GBMs.Conclusions. These results suggest that telomerase activity and p53 mutations both play important roles in the multistep carcinogenesis of GBMs. Telomerase activity and hTERT expression may be considered as novel distinctive factors in human GBMs.
Microanatomy of the pericallosal arterial complex
Authors: Kakou Médard , Destrieux Christophe , Velut Stéphane 
Published: May 2009

Object. The pericallosal arterial complex supplies the callosal and pericallosal regions, as well as the anterior two thirds of the medial and superomedial aspects of both hemispheres. It is composed of the pericallosal artery (that is, the segment of the anterior cerebral artery located distal to the anterior communicating artery [ACoA]) and the median callosal artery (or third pericallosal artery), which originates from the ACoA. This system was studied in 46 specimens (23 human cadaver heads) injected with colored latex.Methods. After being injected with colored latex, embalmed, and bleached, the specimens were studied with the aid of optic magnification.The pericallosal artery was found to be divided into four segments (A2–A5 in the proximodistal direction). After giving rise to central, callosal, and cortical branches, it terminated near the splenium of the corpus callosum as the posterior pericallosal artery, or on the precuneus as the inferomedial parietal artery.Conclusions. The authors propose a logical classification of the different variations in the pericallosal arterial complex based on embryological development. This complex can be considered a hemodynamic solution to an abnormal regression of one of its parts, which is balanced by the development of supplemental channels from other parts.
Multiple pituitary adenomas in Cushing's disease
Authors: Ratliff John K. , Oldfield Edward H. 
Published: May 2009

Object. Clinically evident multiple pituitary adenomas rarely occur. The authors assess the incidence and clinical relevance of multiple adenomas in Cushing's disease.Methods. A prospective clinical database of 660 pituitary surgeries was analyzed to assess the incidence of multiple pituitary adenomas in Cushing's disease. Relevant radiographic scans, medical records, and histopathological reports were reviewed.Thirteen patients with at least two separate histopathologically confirmed pituitary adenomas were identified. Prolactinomas (nine patients) were the most common incidental tumors. Other incidental tumors included secretors of growth hormone ([GH], one patient) and GH and prolactin (two patients), and a null-cell tumor (one patient). In two patients, early repeated surgery was performed because the initial operation failed to correct hypercortisolism, in one instance because the tumor excised at the initial surgery was a prolactinoma, not an adrenocorticotropic hormone—secreting tumor. One patient had three distinct tumors.Conclusions. Multiple pituitary adenomas are rare, but may complicate management of patients with pituitary disease.