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Biomedical subjects

G N Fuller

Publications and source records attributed to G N Fuller.

143 records · Page 8Linked to original sources
PubMedDate not supplied

Intracerebral extension of nasal dermoid cyst: CT appearance.

We report on a 46-year-old man with a congenital nasal dermoid cyst that extended intracranially to form large bifrontal intraaxial dermoid cysts, which became secondarily infected through a nasal dermal sinus tract. Computed tomography demonstrated bilateral frontal lobe ring enhancing cystic masses containing fat-fluid levels consistent with dermoid cyst abscesses. Axial and coronal CT of the skull base and nose demonstrated a midline bony canal extending from two dimples on the dorsum of the patient's nose to the base of the anterior cranial fossa. The clinical, CT, and surgical findings are reviewed as well as the embryogenesis of congenital nasal dermoid cysts.

Brain Neoplasms↗
PubMedDate not supplied

MRI of temporal lobe pleomorphic xanthoastrocytoma.

Pleomorphic xanthoastrocytomas (PXA) are classically supratentorial, peripherally located, well-circumscribed, partially cystic neoplasms, which can enhance on CT following the administration of intravenous contrast agents. Focal calcification may also be seen. Although the CT appearance has been described, we report the MR findings in two cases of histologically documented temporal lobe PXA. The two well-circumscribed lesions were predominantly cystic and both contained a Gd-DTPA enhancing mural nodule. The latter was isointense with gray matter on T1-weighted images and hyperintense on T2-weighted scans. Minimal surrounding edema was present. Histologically, PXA may be confused with glioblastoma multiforme (GBM) due to the pronounced cellular pleomorphism. Because of their potentially more indolent behavior compared with GBM, it is important to recognize the gross morphologic characteristics of this rare tumor on MR. The MR pattern of a cystic lesion with enhancing mural nodule is characteristic of PXA, but not diagnostic, and other lower grade gliomas such as ganglioglioma and pilocytic astrocytoma need to be considered. The MR and CT appearance of PXA can provide critical information for the pathologist, especially when only a small amount of tissue is obtained for histologic evaluation.

Adult↗
PubMedDate not supplied

Characterization of cellular pathways involved in glioblastoma response to the chemotherapeutic agent 1, 3-bis(2-chloroethyl)-1-nitrosourea (BCNU) by gene expression profiling.

The effectiveness of chemotherapy for human cancers is limited by pharmacokinetic parameters such as variation in metabolism and is determined by the cellular response. In this work, we aimed to gain a more holistic understanding of the molecular basis of glioma response to the DNA-alkylating agent 1, 3-bis(2-chloroethyl)-1-nitrosourea (BCNU) by using a systematic approach: we investigated the expression of 588 genes with various cellular functions in a BCNU-resistant glioblastoma cell line and a BCNU-sensitive subline before and after treatment with BCNU. Our gene expression profiling revealed major differences in gene expression between these two cell lines, especially after treatment with BCNU. One striking example was that BCNU decreased the expression of six DNA-repair genes in sensitive but not in resistant cells. In sensitive cells, BCNU treatment resulted in the induction of two MAP kinase genes; this finding suggests that the specific response to BCNU in sensitive cells may involve the Jun kinase signal transduction pathway. After BCNU treatment, marked induction of tumor necrosis factor was detected only in sensitive cells, suggesting that tumor necrosis factor is a mediator of BCNU-induced cell death. Bcl-2 family members were not altered by BCNU in sensitive cells, suggesting that BCNU-induced cell death may be independent of the bcl-2 pathway. Results of the present study demonstrate that gene expression profiling may facilitate identification of cellular pathways associated with specific responses to chemotherapeutic agents and contribute to an understanding of the molecular basis of drug action.

Antineoplastic Agents, Alkylating↗
PubMedDate not supplied

Clinical training of specialist registrars in neurology: the registrar's perspective.

OBJECTIVES: To find out how closely consultants supervise specialist neurology registrars in different clinical settings (acute admissions, routine admissions, ward referrals, new outpatients and old outpatients) and how much registrars value this supervision. DESIGN: Questionnaire asked: how often clinical assessments were done (from 'not done' to 'almost always'); how useful these were for training (from 'not useful' to 'very useful'). SUBJECTS: Distributed via regional education supervisors to registrars in their region. RESULTS: Sixty-one responses from 88 distributed questionnaires (69%). Acute admissions were closely supervised (> 80%) and valued as training. Routine admissions and ward referrals were less frequently reviewed, though review was valued. New outpatients were reviewed 'infrequently' or 'not at all' in 65%, though review was valued for training (> 80%). Old outpatients were less frequently reviewed but this was less valued. CONCLUSIONS: Inpatient supervision of neurology trainees is close and valued by trainees, though review of ward referrals is often a missed opportunity for training. Outpatient supervision is limited, though highly valued by trainees. Time needs to be made available within the outpatient clinic to allow supervision and training.

Adult↗
PubMedDate not supplied

Cytogenetic and molecular genetic abnormalities in primitive neuroectodermal tumors of the central nervous system.

Primitive neuroectodermal tumors constitute a large class of pediatric brain tumors. Despite notable recent advances in improving treatment and survival, the pathogenesis and the molecular genetic bases of these malignancies remain poorly understood. Combined cytogenetic and molecular genetic approaches have been used to identify genomic alterations in different histologic tumor types. Translation of these advances from basic science to clinical application is currently underway. Goals for the future include the development of more efficacious treatment strategies while simultaneously lessening toxicity. The most important cytogenetic and molecular genetic abnormalities documented to date together with their potential prognostic significance are reviewed.

Aneuploidy↗
PubMedDate not supplied

Granular cell tumor of intracranial meninges.

BACKGROUND: Granular cell tumor (GCT) is a benign neoplasm composed of a proliferation of round or polygonal cells that contain eosinophilic granular cytoplasm. The most common locations are tongue and subcutaneous tissue, but a variety of other sites may be involved including the central nervous system (CNS). Most CNS GCT arise in the pituitary, but rare cases involving brain and leptomeninges have been described. Extracranial GCT are usually S-100-positive, but those of the CNS, as well as the congenital variant of GCT, can be S-100-negative. CASE REPORT: We report an incidental autopsy finding of a 2.5 mm GCT that arose in the intracranial meninges overlying the anterior superior cerebellar vermis. RESULTS: The neoplasm had abundant eosinophilic, granular cytoplasm that was PAS-positive and diastase-resistant. Immunohistochemical studies showed that the neoplasm was positive for CD68 and negative for S-100, GFAP, EMA, and keratin. Thus, the immunophenotype is consistent with non-neural origin. CONCLUSION: Although this lesion in this circumstance was of no clinical significance, knowledge of the occurrence of GCT at this site broadens the differential diagnosis of eosinophilic lesions of the leptomeninges.

Biomarkers, Tumor↗
PubMedDate not supplied

Arterial border zone necrosis of the spinal cord.

A 74-year-old man developed necrosis of the spinal cord following an episode of severe hypotension associated with dissection of the aorta. The area of necrosis was confined to the arterial border zone between the anterior and posterior spinal arteries, and involved both gray and white matter symmetrically. The periphery of the cord was spared. Only the lower thoracic cord, which represents a border zone between segmental radicular arteries, was involved. Extensive arterial border zone necrosis was also present in the cerebral cortex and cerebellum. The fact that arterial border zone necrosis is much less common in the spinal cord than in the brain suggests that its development requires a local compromise of the spinal cord circulation in addition to systemic arterial hypotension.

Aged↗
PubMedDate not supplied

Nervus terminalis (cranial nerve zero) in the adult human.

The presence of an additional cranial nerve (the nervus terminalis or cranial nerve zero) is well documented in many non-human vertebrate species. However, its existence in the adult human has been disputed. The present study focused on the structure and incidence of this nerve in the adult human brain. The nerve was examined post-mortem in 10 adult brains using dissection microscopy, light microscopy, transmission electron microscopy, and immunohistochemistry. In all specimens, the nervus terminalis was identified bilaterally as a microscopic plexus of unmyelinated peripheral nerve fascicles in the subarachnoid space covering the gyrus rectus of the orbital surface of the frontal lobes. The plexus appeared in the region of the cribriform plate of the ethmoid and coursed posteriorly to the vicinity of the olfactory trigone, medial olfactory gyrus, and lamina terminalis. We conclude that the terminal nerve is a common finding in the adult human brain, confirming early light microscopic reports.

Adult↗
PubMedDate not supplied

Carotid body tumor: flow sensitive pulse sequences and MR angiography.

The magnetic resonance (MR) appearance of carotid body tumors has been previously described. Classically, these lesions are well circumscribed and highly vascular and cause a characteristic separation of the external and internal carotid arteries. Hypointense foci within these tumors are seen on T1-weighted images. The T2-weighted images snow a "salt and pepper" pattern. We report a carotid bifurcation glomus tumor that exhibited the above features on conventional MR. Multiplanar gadolinium enhanced MR as well as flow-sensitive MR techniques including small flip angle gradient refocused images and MR angiography were performed. Magnetic resonance angiography demonstrated the abnormal morphology of the carotid bifurcation. Axial gradient refocused images revealed evidence of flow within the lesion. The findings were then correlated with postcontrast CT, arterial digital subtraction angiography, and histopathology.

Carotid Body Tumor↗
PubMedDate not supplied

Vasculitic neuropathy.

Vasculitic neuropathy usually receives only a footnote in neurology textbooks. The condition is rare, but as it is potentially treatable it merits wider discussion. This article discusses the pathological features, clinical features and associations of vasculitic neuropathy. It recommends a scheme for investigating patients and summarizes treatment and prognosis.

Biopsy, Needle↗