Thyroid transcription factor 1 expression in sellar tumors: a histogenetic marker?

Pituicytomas are rare low-grade gliomas of the neurohypophysis. Their morphology and variable immunophenotype have led to speculation that they arise from pituicytes. Given the role of thyroid transcription factor 1 (TTF-1) in the developing rodent infundibulum and its expression in the adult rat neurohypophysis, we speculated that TTF-1 would be a marker of human pituicytes.

Primary diffuse leptomeningeal gliomatosis mimicking a chronic inflammatory meningitis.

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare, fatal, neoplastic condition of infiltrating glial cells into the meninges without evidence of primary tumor in the brain or spinal cord parenchyma. Primary diffuse leptomeningeal gliomatosis often presents with symptoms and physical findings of chronic inflammatory meningitis and raised intracranial pressure, and lacks specific clinical, radiologic, and diagnostic criteria. We report a case of PDLG diagnosed post-mortem, highlighting the diagnostic difficulty in identifying PDLG as the cause of chronic meningitis, even when a neoplastic etiology is suspected.

Supranuclear vertical gaze abnormalities in sporadic Creutzfeldt-Jakob disease.

Supranuclear gaze palsies are an uncommon feature of Creutzfeldt-Jakob disease (CJD). Most reported cases of CJD with features of supranuclear gaze palsy are familial. We report 2 patients with supranuclear vertical gaze abnormalities associated with spongiform changes in the midbrain.

Fragmentation of the Golgi apparatus in neurodegenerative diseases and cell death.

Fragmentation of the neuronal Golgi apparatus (GA) was reported in amyotrophic lateral sclerosis (ALS), corticobasal degeneration, Alzheimer's and Creutzfeldt-Jacob disease, and in spinocerebelar ataxia type 2 (SCA2). In transgenic mice expressing the G93A mutant of Cu/Zn superoxide dismutase (SOD1) of familial ALS (fALS), fragmentation of the GA of spinal cord motor neurons and aggregation of mutant protein were detected months before the onset of paralysis. Moreover, cells that expressed the G93A and G85R mutants of SOD1 showed fragmentation of the GA and decreased viability without apoptosis.

Effect of ubiquitin expression on neuropathogenesis in a mouse model of familial amyotrophic lateral sclerosis.

The ubiquitin-proteasome system (UPS) is a central component in the cellular defence against potentially toxic protein aggregates. UPS dysfunction is linked to the pathogenesis of both sporadic and inherited neurodegenerative diseases, including dominantly inherited familial amyotrophic lateral sclerosis (fALS). To investigate the role of the UPS in fALS pathogenesis, transgenic mice expressing mutant G9 3A Cu,Zn superoxide dismutase (SOD1) were crossed with transgenic mice expressing epitope tagged, wild-type or dominant-negative mutant ubiquitin (Ub(K48R)).