145 research outputs found
Delayed chronic intracranial subdural hematoma complicating resection of a tanycytic thoracic ependymoma
Background: To demonstrate that the diagnosis of an intracranial subdural hematoma should be considered for patients presenting with acute or delayed symptoms of intracranial pathology following resection of a spinal tumor. Case Description: We present a case of a 57-year-old woman found to have a chronic subdural hematoma 1 month following resection of a thoracic extramedullary ependymoma. Evacuation of the hematoma through a burr hole relieved the presenting symptoms and signs. Resolution of the hematoma was confirmed with a computed tomography (CT) scan. Conclusion: Headache and other symptoms not referable to spinal pathology should be regarded as a warning sign of an intracranial subdural hematoma, and a CT scan of the head should be obtained. The mechanism of the development of the hematoma may be related to the leakage of cerebrospinal fluid with subsequent intracranial hypotension leading to an expanding subdural space and hemorrhage
High Grade Glioma Treatment in Elderly People: Is It Different Than in Younger Patients? Analysis of Surgical Management Guided by an Intraoperative Multimodal Approach and Its Impact on Clinical Outcome
Objective: Age is considered a negative prognostic factor for High Grade Gliomas (HGGs) and many neurosurgeons remain skeptical about the benefits of aggressive treatment. New surgical and technological improvements may allow extended safe resection, with lower level of post-operative complications. This opportunity opens the unsolved question about the most appropriate HGG treatment in elderly patients. The aim of this study is to analyze if HGG maximal safe resection guided by an intraoperative multimodal imaging protocol coupled with neuromonitoring is associated with differences in outcome in elderly patients versus younger ones. Methods: We reviewed 100 patients, 53 (53%) males and 47 (47%) females, with median (IQR) age of 64 (57; 72) years. Eight patients were diagnosed with Anaplastic Astrocytoma (AA), 92 with Glioblastoma (GBM). Surgery was aimed to achieve safe maximal resection. An intraoperative multimodal imaging protocol, including neuronavigation, neurophysiological monitoring, 5-ALA fluorescence, 11C MET-PET, navigated i-US system and i-CT, was used, and its impact on EOTR and clinical outcome in elderly patients was analyzed. We divided patients in two groups according to their age: 65 years, and surgical and clinical results (EOTR, post-operative KPS, OS and PFS) were compared. Yet, to better understand age-related differences, the same patient cohort was also divided into 70 years and all the above data reanalyzed. Results: In the first cohort division, we did not found KPS difference over time and survival analysis did not show significant difference between the two groups (p = 0.36 for OS and p = 0.49 for PFS). Same results were obtained increasing the age cut-off for age up to 70 years (p = 0.52 for OS and p = 0.92 for PFS). Conclusions: Our data demonstrate that there is not statistically significant difference in post-operative EOTR, KPS, OS, and PFS between younger and elderly patients treated with extensive tumor resection aided by a intraoperative multimodal protocol
Graph-Based Clustering Approaches for Gene Network Reconstruction
為了解生物基因間的調控關係,生物學家常利用干擾性核醣核酸(RNAi),或是基因剔除(gene knockout)的方式來觀察生物系統的反應。資訊學家則嘗試利用演算法以mRNA隨時間變化的表現量曲線重建出可能的基因間調控關係。然而,基因間的調控包含許多階段,包括轉錄 (Transcription)、轉錄後修飾(Post-transcriptional modification) 、轉譯 (Translation) 、mRNA的降解 (mRNA degradation) 、轉譯後修飾 (Post-translational modification)等。這些階段都需要時間來反應,因此許多研究根據時間延遲的特徵,分析基因間的調控關係。這份研究中,我們使用兩個方法來重建基因網路。一個是Normalized Cuts以圖學方式試著將有功能性的基因調控網路分割出來。另一個方法則是PARE (Pattern Recognition Approach)演算法,一個以時間延遲(time-lagged)以及非線性特徵作為基因間調控關係的推論演算法。我們使用酵母菌的mRNA隨時間變化的表現量作為重建基因調控網路的分析材料,再以KEGG pathway資料庫、BIOGRID 交互影響資料庫與MIPS資料庫做為比較分析的參考。而從分析出的F score結果來看,我們的方法優於Kim等人所發展出的動態貝式網路。後,我們將方法應用到一個實際的例子,yox1與yhp1兩個基因皆剔除的酵母菌的生物晶片上,分析其mRNA隨時間變化的表現量。由於細胞每段時期間轉換機制尚未完全被了解,目前已知yox1與yhp1是以負回饋的機制控制細胞在G1時期的時間。我們成功地找到與細胞生命週期相關的調控網路,其中一個調控網路與細胞分裂相關。藉由這份應用結果,我們期望能夠探究出更多關於細胞生命週期中每個時期轉換間的調控機制。To understand regulatory relationships between genes in real life. Biologists often use RNA interference (RNAi) or knockout genes to observe the response in the real life system. Informationists try to reconstruct regulatory relationship between genes from mRNA expression profile by algorithms or mathematic models. There are several phases involved in gene regulation such as transcription, post-transcriptional modifications, translation, RNA degradation and post-translational modifications .Time is essential for all these phases to be completed and many researches analyze regulation via these features. n this study, we use two methods to reconstruct regulatory relationships between genes. One is a graph partition algorithm named Normalized Cuts for partitioning off genes into functional gene network. The other method, PARE (Pattern Recognition Approach), an algorithm based on time-lagged non-linear feature of the profile, is to infer regulation between genes. In addition, we use yeast microarray to construct gene regulatory networks and check results from KEGG pathway database, BIOGRID interaction database and MIPS database. Comparing our F score result with Dynamic Bayesian Network developed by Kim, et al., it shows that our method performs better than theirs. inally, we apply our method to a real case in yeast microarray in which yox1 and yhp1 are both deleted and we analyze its mRNA expression time profile. Although mechanisms between phases in cell cycle are not clear, yox1 and yhp1 are two genes known controlling duration of a cell in G1 phase by negative feedback. We successfully find networks associated with cell cycle and one of the networks is associated with cell mitosis. In the future, we hope to decipher more mechanisms between phases in cell cycle.口試委員審定書 i謝 ii要 iiibstract iv錄 v目錄 vii目錄 ix一章 序論 1.1研究背景 1.2研究動機 2.3研究目的 4二章 文獻探討 6.1基因網路重建演算法與模型的探討 6.2關於時間延遲的文獻探討 12三章 研究方法與材料 16.1以圖形理論方式重建網路 16.2 Normalized Cuts 19.3 PARE (Pattern Recognition Approach) 23.4 演算法流程 26.5生物驗證與應用材料 29.5.1生物驗證比對資料 29.5.2生物應用資料 30四章 研究成果與討論 31.1生物驗證比較資料結果 31.1.1 Dynamic Bayesian重建細胞代謝網路在BIOGRID上的比對 32.1.2 Dynamic Bayesian重建細胞生命週期網路在BIOGRID上的比對 33.1.3 圖形群聚演算法重建細胞代謝網路在BIOGRID上的比對 34.1.4 圖形群聚演算法重建細胞生命週期網路在BIOGRID上的比對 35.1.5 Dynamic Bayesian重建細胞代謝網路在MIPS上的比對 37.1.6 Dynamic Bayesian重建細胞生命週期網路在MIPS上的比對 38.1.7 圖形群聚演算法重建細胞代謝網路在MIPS上的比對 39.1.8 圖形群聚演算法重建細胞生命週期網路在MIPS上的比對 40.1.9兩種方法重建細胞代謝網路在KEGG上的比對 42.1.10兩種方法重建細胞生命週期網路在KEGG上的比對 45.2生物應用資料結果 49.3 生物應用資料討論 51五章 結論與展望 54考文獻 56錄 6
Protective effect of spinal cord stimulation on experimental early cerebral vasospasm - Conclusive results
In this study we investigate the effects of cervical spinal cord stimulation (cSCS) on experimental 'early spasm' in rabbits as described in personal previous experience (Acta Neurochir 2001;143:177-185). Twenty-four adult red Burgundy rabbits wearing a cervical epidural electrode underwent cerebral blood flow (CBF) and functional monitoring of early basilar spasm before and during cSCS. CBF changes, as a consequence of cSCS, occurred in 20 control animals. No CBF changes, consistent with no basilar artery vasospasm, occurred after subarachnoid haemorrhage (SAH) up to the end of the experiments in all the stimulated animals. The role of reversible functional sympathectomy in mediating the effect of spinal cord stimulation on early spasm is discussed. cSCS is able to prevent 'early spasm' due to SAH in all the animals studied, independently from the occurrence and the sign of stimulation induced CBF variations. Copyright (C) 2002 S. Karger AG, Basel
Familial Replicating Arachnoidal Cysts: Case Series and Review of Literature
Background: Arachnoid cysts are intra-arachnoid fluid collections covered by a thin membrane that may develop
throughout the cerebrospinal axis. Although the precise causative mechanism is unknown, arachnoid cyst (AC) are
now generally accepted to be developmental anomalies of arachnoid. These lesions have commonly been described
in the literature; however the presence of familial arachnoid cysts is quite rare. Most genetically related AC have been
documented in patients with a known genetic syndrome. The current case report describes a family with four members
affected by an arachnoid cyst in the same region.
Methods: In addition to reviewing the current case, a literature search was conducted using National Library of
Medicine and National Institutes of Health databases to identify articles pertaining to familial Arachnoid cysts. Overall,
32 published articles fit the established review criteria
Results: We describe a family whose members (father and three siblings) present an arachnoid cyst in the same
region (the left middle cranial fossa). The general physical findings in the four members were normal and no clinical
suggestion of a genetic syndrome. None of the members had an increased head size or abnormal cutaneous findings.
Histories of prenatal and perinatal periods were unremarkable. All were born normally at term and none had any history
of intrauterine exposure to infection, drugs, teratogens or trauma. Karyotyping failed to reveal abnormalities.
Conclusion: This report extends previous observations that AC can be familial and supports the hypothesis that
some cases have a genetic aetiology. The lack of chromosomal or genetic studies in these patients supports the need
for additional research into the mechanism of AC formation
Craniocervical junction instability: instrumentation and fusion with titanium rods and sublaminar wires. Effectiveness and failures in personal experience
Background. The aim of the study was to evaluate the effectiveness, pitfalls and failures of instrumentation and fusion with titanium wires and rods in 12 h patients with cramovertebral junction instability. Methods. Among nine adult patients (mean age 48.11 years) with cramovertebral junction instability, four had basilar impression, three metastatic disease, one rheumatoid arthritis and one Down's syndrome. Three children (mean age 7.33 years) with genetic (Down's syndrome, 2 cases) and metabolic (mucopolisaccarydoses type IV, i.e. Morquio Syndrome, I case) disease were studied as well. Each patient underwent preoperative radiological evaluation by means of X-Ray, CT scan and MRI of the craniocervical region. Occipitocervical instrumentation with a titanium U-shaped wired rod was performed in each patient. Autologous bone fusion was performed in all but the two cancer patients, in whom polymethylmetacrylate was used. Postoperatively, all the patients used an external orthosis for 3-6 months. Post-operative X-Ray, CT and MRI were performed on each patient. The Frankel clinical scale was used to asses the outcome at follow-up which ranged from I to 10 years. At maximum follow up, there was either clinical improvement or stabilization recorded in all but one patient. This patient with basilar impression transiently worsened from grade D to C and a spinal cord lesion was already evident before the operation on MRI examination. Interpretation. The effectiveness of surgical management of cramovertebral junction instability by instrumentation and fusion was demonstratedly in our experience. Nevertheless, the choice of the surgical technique should be made with caution when a spinal cord lesion is revealed by preoperative neuroimaging studies
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