Biomedical subjects

Melike Mut

Publications and source records attributed to Melike Mut.

10 recordsLinked to original sources

PubMed2005

Lucien J. Rubinstein: enduring contributions to neuro-oncology.

Dr. Lucien Rubinstein is best remembered for his significant contributions to the field of neuropathology, particularly in the classification of nervous system tumors. His accomplishments in basic neuro-oncology and in the formulation of diagnostic principles reflected a unique talent for synthesizing fundamental clinicopathological concepts based on skillful diagnostic investigation and a thorough understanding of neurobiology. Dr. Rubinstein was the leader in the establishment of cell cultures from central nervous system (CNS) tumors. He meticulously analyzed both light and electron microscopic features of CNS tumors, recorded his findings, and patiently drew sketches to be shared generously with his colleagues and students. As a pioneer in neuropathology, in his work Dr. Rubinstein set the foundation for many enduring concepts in neurosurgery, neuro-oncology, neurology, and basic tumor biology.

Biomarkers, Tumor↗

PubMed2005

Paraneoplastic recurrent multifocal encephalitis presenting with epilepsia partialis continua.

We report a 46-year-old female patient in whom epilepsia partialis continua was the initial presentation of small cell lung cancer. Magnetic resonance imaging revealed multiple, bilateral cortical lesions, which were originally misinterpreted and treated as brain metastases. Intracranial lesions and neurological symptoms remitted after corticosteroids, chemotherapy, and radiotherapy. After an asymptomatic interval of 18 months, neurological symptoms recurred with more extensive involvement of completely different parts of the central nervous system (limbic, brainstem and cerebellar structures) without any evidence of tumor recurrence. Both episodes showed a distinctive response to immunosuppressive therapy. The diagnostic challenges of the highly variable clinical presentations and therapeutic approaches to paraneoplastic multifocal encephalitis are discussed with relevant literature review.

Adrenal Cortex Hormones↗

PubMed2005

Metastasis to nervous system: spinal epidural and intramedullary metastases.

Spinal cord epidural metastasis (SEM) is a common complication of systemic cancer with an increasing incidence. Prostate, breast and lung cancer are the most common offenders. Metastasis usually arises in the posterior aspect of vertebral body with later invasion of epidural space. Pathophysiologically, vascular insufficiency is more important than direct spinal cord compression. The most common complaint is pain, and two thirds of patients with SEM have motor signs at initial diagnosis. Currently magnetic resonance imaging is the most sensitive diagnostic tool. The optimal management of SEM is still arguable, but recent advances in surgical management of SEM and higher complication rate of surgery following radiotherapy should persuade clinicians to consider de novo surgery where possible. Radiotherapy has an important role, particularly in treatment of radiosensitive tumors and in patients who are not candidates for surgery. Novel approaches such as stereotactic radiosurgery are promising; however, response to chemotherapy depends on inherent properties of primary tumor. Recurrent SEM is a substantial problem for which surgery or repeat radiotherapy may be options. Intramedullary metastasis is rare but should be considered in patients with systemic malignancy and asymmetrical presentation of myelopathic symptoms. The prognosis is usually poor and preferred modality of treatment is radiotherapy.

Epidural Neoplasms↗

PubMed2005

Multilevel myelopathy in Maroteaux-Lamy syndrome and review of the literature.

An 18-year-old male with Maroteaux-Lamy syndrome was presented with spastic quadriparesis. Magnetic resonance imaging of whole spinal canal revealed stenosis at multiple levels of cervical, thoracic and lumbar regions. By the guidance of combined evaluations of neurological examination, neuroradiological and electrophysiological findings, the most responsible spinal segment was detected each time he developed myelopathy and he underwent craniocervical, cervical and thoracolumbar decompressions consecutively. Ligamentum flavum hypertrophy was found to be the principal pathology responsible for the cord compression and myelopathy for all levels. The etiology of myelopathy and priority of the level for which decompression should be done in diffuse spinal stenosis were discussed with the literature review of Maroteaux-Lamy syndrome.

Adolescent↗

PubMed2005

The Ki-67 labeling index as a prognostic factor in Grade II oligoastrocytomas.

OBJECT: This study was conducted to determine whether proliferative tumor activity, as assessed using the Ki-67 immunohistochemical labeling index (LI), has prognostic utility for patients with Grade II oligoastrocytomas. METHODS: The study period spans the years 1988 to 2000. In a retrospective analysis, the authors selected cases with biopsy-proven diagnoses of Grade II oligoastrocytomas on initial presentation. The authors added new patients to this group and followed all patients prospectively at the University of Virginia Neuro-Oncology Center. Twenty-three adult patients were followed for at least 1 year (median 40.3 months). Eleven patients with Grade II tumors and initial Ki-67 LIs less than 10% had a significantly longer median time to tumor progression (TTP, 51.8 months compared with 9.9 months) and a longer median survival (93.1 months compared with 16.1 months) than 12 patients with initial Ki-67 LIs of 10% or greater. Twelve patients with Grade III oligoastrocytomas had a mean TTP that was similar to the TTP of patients with Grade II tumors and high Ki-67 LIs (mean 4 months compared with 9.9 months) and duration of survival (13.3 months compared with 16.1 months). CONCLUSIONS: Patients with a Grade II oligoastrocytoma and a Ki-67 LI of 10% or greater have a much shorter TTP and potentially a poorer disease prognosis than expected--more similar to patients with a Grade III oligoastrocytoma. These results indicate that in the future a measure of proliferative activity should be taken into consideration along with the World Health Organization grading criteria for oligoastrocytomas.

Adult↗

PubMed2004

The effects of chronic hypoperfusion on rat cranial bone mineral and organic matrix. A Fourier transform infrared spectroscopy study.

Arteriovenous malformations (AVM) of the brain, errors in the development of the vasculature, produce high flow arteriovenous shunts. They steal blood from surrounding brain tissue, which is chronically hypoperfused. Hypoperfusion is a condition of inadequate tissue perfusion and oxygenation resulting in abnormal tissue metabolism. In the present study Fourier transform infrared (FTIR) spectroscopy was used to investigate the effects of hypoperfusion on rat cranial bone mineral and organic matrix at the molecular level. FTIR spectroscopic analysis revealed that in cranial bones of an experimental group the relative amount of carbonate and phosphate groups increased whereas that of protein (amide I) decreased. Curve-fitting analysis of the v(2) carbonate band showed that amounts of type A and type B carbonates increased slightly ( p=0.423 for both) whereas, type L carbonate decreased slightly ( p=0.522) in hypoperfused cranial bones. Analysis of the C-H region revealed a significant increase ( p=0.037) in the lipid to protein ratio. Because the lipid content is high, hypoperfused cranial bone tissue is more prone to lipid peroxidation. Dialdehydes derived from lipid peroxidation can make cross-links with collagen and might lead to disturbances in the collagen cross-link profile. The 1660 cm(-1)/1690 cm(-1) partial area ratio derived from curve-fitting analysis of the Amide I band is sensitive to the relative amount of collagen non-reducible cross-link hydroxylysyl/lysylpyridinolines (Pyr) and reducible cross-link dihydroxylysinonorleucine (DHLNL) and this ratio reflects collagen maturity. In chronic hypoperfusion a significant decrease ( p=0.004) was observed in this ratio. This means there were less mature collagen cross-links. Disturbances in the collagen maturation can affect mineralization process and lead to formation of pathologic structures in cranial bones. These findings clearly demonstrate that FTIR spectroscopy can be used to extract valuable information at molecular level, leading to better understanding of the effect of hypoperfusion on rat cranial bones.

Animals↗

PubMed2004

Eosinophilic granuloma of the skull associated with epidural haematoma: a case report and review of the literature.

INTRODUCTION: Eosinophilic granuloma (EG), a benign bone lesion, represents a focal form of histiocytosis X. Here, the authors report a case of an extremely rare presentation of a solitary EG of the skull. CASE REPORT: A 9-year-old boy presented with headache and vomiting for 3 days. His examination was unremarkable except for a tender mass in his left occipital region. Radiological studies revealed a huge bilateral epidural haematoma under the occipital bone, extending supratentorially and infratentorially, and a nonenhanced, epidural, soft tissue mass overlying the left transverse sinus. Evacuation of the epidural haematoma was performed and it was noted that the left transverse sinus wall was eroded by the EG at one point with venous oozing. REVIEW OF THE LITERATURE: The acute presentation of a solitary EG of the skull with an epidural haematoma was described in only four cases in the literature. This is the first documented case in terms of the origin of an epidural haematoma.

Brain↗

PubMed2004

Brain metastases.

Explore the source record for details and available documents.

Antineoplastic Agents↗

PubMed2004

Radiation-induced malignant triton tumor associated with severe spinal cord compression. Case report and review of the literature.

Malignant triton tumor (MTT) is a variant of malignant peripheral nerve sheath tumors. The authors report a case of radiation-induced MTT in a patient with severe cervicothoracic cord compression and review the related literature. This 36-year-old man presented with pain and weakness in his left arm. His medical history was significant for a biopsy procedure involving the sampling of an aneurysmal bone cyst located at T1-3 near the left lung apex; this was performed 6 years prior to presentation and was followed by radiotherapy. Neurological examination demonstrated radicular findings involving the left C-8 and T-1 nerve roots. Neuroimaging studies revealed a large mass lesion extending from C-6 to T-2 along the vertebral column, invading the upper thoracic cavity and the adjacent lung apex, and infiltrating the paravertebral muscles. A subtotal resection was performed, but the tumor regrew extensively within a short time. It invaded the spinal canal and caused significant cord compression. The patient underwent surgery two more times for tumor debulking and to relieve progressive airway and spinal canal compromise. He eventually became quadriplegic, however, and died 13 months after diagnosis of MTT. This is the seventh case of radiation-induced MTT and the fifth of MTT with spinal canal involvement to be reported in the literature.

Adult↗

PubMed2003

Effects of ionizing radiation on brain tissue surrounding arteriovenous malformations: an experimental study in a rat caroticojugular fistula model.

Arteriovenous malformation (AVM) may change the cerebral hemodynamics. The purpose of this study was to detect the effects of ionizing radiation (IR) on tissues surrounding AVM in a rat caroticojugular fistula model. Forty rats were divided into four groups. Eight weeks after caroticojugular fistulas and chronic hypoperfusion were created in groups 1 and 2, IR was administered to groups 1 and 3. Group 4 was the control. Brain tissue samples were taken 72 h after irradiation. Comet assay to detect DNA strand breaks (DSB), terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay for apoptosis, and free radical measurement were performed. Although the difference between fistula plus irradiation (group 1) and fistula (group 2) was statistically insignificant in terms of DSB and free radical measurement, apoptotic cell count was significantly higher in group 1. Nonetheless, apoptotic cell count corresponded well with both free radicals and DSB in the irradiated group (group 3). Ionizing radiation resulted in significant apoptosis in both groups with or without fistulas. Chronic hypoperfusion might not prevent cerebral damage after IR. Optimal care should be taken with brain tissue around AVM during radiotherapy, regardless of presence or absence of the "steal" phenomenon.

Animals↗