Objective Heightened awareness of Creutzfeldt-Jakob disease (CJD) among physicians and the lay public has led to its frequent consideration in the differential diagnosis of patients with rapidly progressive dementia (RPD). Our goal was to determine which treatable disorders are most commonly mistaken for CJD. Methods We performed a retrospective clinical and neuropathological review of prion-negative brain autopsy cases referred to the US National Prion Disease Pathology Surveillance Center (NPDPSC) at Case Western Reserve University from January 2006 through December 2009. Results Of 1,106 brain autopsies, 352 (32%) were negative for prion disease, 304 of which had adequate tissue for histopathological analysis. Alzheimer disease (154) and vascular dementia (36) were the two most frequent diagnoses. Seventy one patients had potentially treatable diseases. Clinical findings included dementia (42 cases), pyramidal (20), cerebellar (14), or extrapyramidal (12) signs, myoclonus (12), visual disturbance (9) and akinetic mutism (5); a typical electroencephalogram occurred only once. Neuropathological diagnoses included immune-mediated disorders (26), neoplasia (25, most often lymphoma), infections (14), and metabolic disorders (6). Interpretation In patients with RPD, treatable disorders should be considered and excluded before diagnosing CJD. Misdiagnosed patients often did not fulfill WHO criteria. RPD with positive 14-3-3 CSF protein should not be regarded as sufficient for the diagnosis of CJD. Adherence to revised criteria for CJD, which include distinctive MRI features of prion disease, is likely to improve diagnostic accuracy.

Human adenovirus has evolved to infect and replicate in terminally differentiated human epithelial cells, predominantly those within the airway, the gut, or the eye. To overcome the block to viral DNA replication present in these cells, the virus expresses the Early 1A proteins (E1A). These immediate early proteins drive cells into S-phase and induce expression of all other viral early genes. During infection, several E1A isoforms are expressed with proteins of 289, 243, 217, 171, and 55 residues being present for human adenovirus type 5. Here we examine the contribution that the two largest E1A isoforms make to the viral life cycle in growth-arrested normal human fibroblasts. Viruses that express E1A289R were found to replicate better than those that do not express this isoform. Importantly, induction of several viral genes was delayed in a virus expressing E1A243R, with several viral structural proteins undetectable by western blot. We also highlight the changes in E1A isoforms detected during the course of viral infection. Furthermore, we show that viral DNA replication occurs more efficiently, leading to higher number of viral genomes in cells infected with viruses that express E1A289R. Finally, induction of S-phase specific genes differs between viruses expressing different E1A isoforms, with those having E1A289R leading to, generally, earlier activation of these genes. Overall, we provide an overview of adenovirus replication using modern molecular biology approaches and further insights into the contribution that E1A isoforms make to the life cycle of human adenovirus in arrested human fibroblasts.

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The adenovirus E1A gene is the first gene expressed upon viral infection. E1A remodels the cellular environment to maximize permissivity for viral replication. E1A is also the major transactivator of viral early gene expression and a coregulator of a large number of cellular genes. E1A carries out its functions predominantly by binding to cellular regulatory proteins and altering their activities. The unstructured nature of E1A enables it to bind to a large variety of cellular proteins and form new molecular complexes with novel functions. The C terminus of E1A is the least-characterized region of the protein, with few known binding partners. Here we report the identification of cellular factor DREF (ZBED1) as a novel and direct binding partner of E1A. Our studies identify a dual role for DREF in the viral life cycle. DREF contributes to activation of gene expression from all viral promoters early in infection. Unexpectedly, it also functions as a growth restriction factor for adenovirus as knockdown of DREF enhances virus growth and increases viral genome copy number late in the infection. We also identify DREF as a component of viral replication centers. E1A affects the subcellular distribution of DREF within PML bodies and enhances DREF SUMOylation. Our findings identify DREF as a novel E1A C terminus binding partner and provide evidence supporting a role for DREF in viral replication. IMPORTANCEThis work identifies the putative transcription factor DREF as a new target of the E1A oncoproteins of human adenovirus. DREF was found to primarily localize with PML nuclear bodies in uninfected cells and to relocalize into virus replication centers during infection. DREF was also found to be SUMOylated, and this was enhanced in the presence of E1A. Knockdown of DREF reduced the levels of viral transcripts detected at 20 h, but not at 40 h, postinfection, increased overall virus yield, and enhanced viral DNA replication. DREF was also found to localize to viral promoters during infection together with E1A. These results suggest that DREF contributes to activation of viral gene expression. However, like several other PML-associated proteins, DREF also appears to function as a growth restriction factor for adenovirus infection.T he interaction of the adenovirus early 1A (E1A) proteins with mammalian regulatory factors has been heavily exploited to elucidate the molecular basis by which they control cellular processes (1-5). Studying the interactions of E1A with new cellular targets provides an exciting opportunity to identify and dissect critical mechanisms controlling mammalian transcription, growth, and differentiation, as well as to identify novel viral regulatory mechanisms. The organization of E1A into short peptide motifs (MoRFs) (6) involved in protein interactions has significantly enriched our understanding of eukaryotic protein function. Identification and characterization of novel MoRFs within E1A allow their subsequent detection in other proteins, which suggests novel interactions leading to signifi...