The Epstein-Barr virus (EBV) EBNA-1 protein has a central role in the maintenance of a latent EBV infection and is the only virus-encoded protein expressed in all EBV-associated tumors. EBNA-1 is required for replication of the episomal form of the latent viral genome and transactivates the latency C and LMP-1 promoters. The mechanisms by which EBNA-1 performs these functions are not known. Here we describe the cloning, expression, and characterization of a cellular protein, P32/TAP, which strongly interacts with EBNA-1. We show that P32/TAP is expressed at high levels in Raji cells and is synthesized as a proprotein of 282 amino acids (aa) that is posttranslationally processed by a two-step cleavage process to yield a mature protein of 209 aa. It has been previously reported that P32/TAP is expressed on the cell surface. Our transient expression assays detected full-length P32/TAP (1-282 aa) in the cytoplasm while mature P32/TAP protein localized to the nucleus. Three lines of evidence support P32/TAP interaction with EBNA-1. First, in the yeast two-hybrid system we mapped two interactive N-terminal regions of EBNA-1, aa 40-60 and aa 325-376, each of which contains arginine-glycine repeats. These regions interact with the C-terminal half of P32/TAP. Second, the full-length cytoplasmic P32/TAP protein can translocate nuclear EBNA-1 into the cytoplasm. Third, P32/TAP co-immunoprecipitated with EBNA-1. We have confirmed that a Gal4 fusion protein containing the C-terminal region of P32/TAP (aa 244-282) transactivates expression from a reporter containing upstream Gal4-binding sites. Deletion of the P32/TAP interactive regions of EBNA-1 severely diminished EBNA-1 transactivation of FRTKCAT in transient expression assays. Our data suggest that interaction with P32/TAP may contribute to EBNA-1-mediated transactivation.

Nonalcoholic fatty liver disease (NAFLD) is prevalent in obese patients. We sought to determine the effects of bariatric surgery on the histological features of NAFLD. Two blinded pathologists graded liver biopsies done during bariatric procedures and subsequent operations in 160 patients using the Brunt classification. Data are mean ± SD. Interval between biopsies was 31 ± 26 months. Initial biopsies demonstrated steatosis 77 %, lobular inflammation 39 %, and chronic portal inflammation 56 %. Steatohepatitis was present in 27 %. Grade 2-3 fibrosis was present in 27 %, and cirrhosis was present in one patient. On post-bariatric biopsy, steatosis resolved in 75 %, lobular inflammation resolved in 75 %, chronic portal inflammation resolved in 49 %, and steatohepatitis resolved in 90 %. Fibrosis of any grade resolved in 53 % and improved in another 3 % of patients. Grade 2 fibrosis resolved in 58 %, improved in 3 %, and did not worsen in 11 %. Bridging fibrosis resolved in 29 %, improved in 29 %, and did not worsen in 29 %. Bariatric surgery is associated with resolution of steatosis or steatohepatitis in the majority of patients. More importantly, grade 2 or 3 (bridging) fibrosis is resolved or improved in 60 % of patients. Bariatric surgery should be considered as a treatment of NAFLD in severely obese patients.

The Epstein-Barr virus transactivator Zta triggers lytic gene expression and is essential for replication of the lytic origin, oriLyt. Previous analysis indicated that the Zta activation domain contributed a replication-specific function. We now show that the Zta activation domain interacts with components of the EBV helicase-primase complex. The three helicase-primase proteins BBLF4 (helicase), BSLF1 (primase), and BBLF2/3 (primase-associated factor) were expressed fused to the Myc epitope. When expression plasmids for BBLF4 or BBLF2/3 plus BSLF1 (primase subcomplex) were separately transfected, the proteins localized to the cytoplasm. Interaction between Zta and the components of the helicase-primase complex was tested by examining the ability of Zta to alter the intracellular localization of these proteins. Cotransfection of Zta with Myc-BBLF4 resulted in nuclear translocation of Myc-BBLF4; similarly, cotransfection of Zta with the primase subcomplex led to nuclear translocation of the Myc-BSLF1 and Myc-BBLF2/3 proteins. This relocalization provides evidence for an interaction between Zta and the helicase and Zta and the primase subcomplex. An affinity assay using glutathioneS-transferase–Zta fusion proteins demonstrated that Myc-BBLF4 and Myc-BBLF2/3 plus BSLF1 bound to the Zta activation domain (amino acids 1 to 133). In the nuclear relocalization assay, the amino-terminal 25 amino acids of Zta were required for efficient interaction with the primase subcomplex but not for interaction with BBLF4. Evidence for interaction between oriLyt bound Zta and the helicase-primase complex was obtained in a superactivation assay using an oriLyt-chloramphenicol acetyltransferase (CAT) reporter. Zta activated expression from a CAT reporter containing the complete oriLyt region and regulated by the oriLyt BHLF1 promoter. Cotransfection of the helicase-primase proteins, one of which was fused to a heterologous activation domain, led to Zta-dependent superactivation of CAT expression. This assay also provided evidence for an interaction between the single-stranded DNA binding protein, BALF2, and the Zta-tethered helicase-primase complex. The helicase-primase interaction is consistent with a role for Zta in stabilizing the formation of an origin-bound replication complex.

Cellular angiofibromas (CAF) are rare, benign soft-tissue tumours. The diagnosis of CAF is important given the heavy resemblance to other tumours. Herein, we describe a case of a rapidly growing, very large (13.5 cm) CAF located in the deep pelvis of a middleaged male who presented with difficulty voiding. IntroductionCellular angiofibromas (CAF) are rare, benign soft-tissue tumours first described by Nucci and colleagues in 1997. 1 CAF share pathological features of angiomyofibroblastoma and aggressive angiomyxoma (AAM), but do not fall into either category. The masses are well-circumscribed, typically less than 3.0 cm and show marked female predominance. In 1998, Laskin and colleagues reported 11 of these tumours in male genitalia, 2 and since then there have been only a few case reports. Most have been found in women, primarily in the vulva. [3][4][5] In males, most are found in the scrotum and inguinal region, averaging about 5 to 6 cm in size.2,3 The diagnosis of CAF is important given the heavy resemblance to other tumours, such as AAM, which is known to have a very high rate of local recurrence. 4 Herein, we describe the case of a rapidly growing, very large (13.5 cm) CAF located in the deep pelvis of a middle-aged male who presented with difficulty voiding. Case presentationA 58-year-old man initially presented with right groin/pelvic pain radiating down into his scrotum, as well as decreased urinary flow and decreased ejaculation. Due to refractory symptoms, a computed tomography (CT) scan of the abdomen and pelvis was done which showed a 7 × 7 × 5-cm mass to the right of the prostate extending down to the bulbar urethra. Prior attempts at both transurethral drainage and transperineal aspiration were unsuccessful and he was then referred to our clinic. A pelvic magnetic resonance imaging (MRI) revealed substantial growth; a 11-cm wellcircumscribed lesion abutting the rectum and displacing the urinary bladder and prostate proximally (Fig. 1, Fig. 2). Biopsies showed a benign stromal tumour of genitourinary origin. Resection was recommended via combined abdominal/perineal approach with colorectal surgery and urology.Exploratory laparotomy showed a large encapsulated mass occupying the entirety of the lower pelvis. The mass was dissected off of the prostate with relative ease, but was more difficult distally owing to dense adherence to a 3-cm portion on the anterior surface of the bulbar urethra. The mass was carefully freed from the rectum through the perineal incision. Ultimately, the intact mass in its entirety was removed with no evidence of residual disease. The specimen was sent to pathology and was read as a large benign spindle cell tumour mostly consistent with a CAF. Gross descriptionThis was an encapsulated, well-circumscribed mass with a thin fibrous capsule. It was elongated and measured 13.5 × 7.4 × 3.7 cm (Fig. 3). The mass felt rubbery and sectioning revealed a gelatinous, tan-pink to grey surface that was focally trabeculated. Microscopic descriptionThe mass consisted of loosely ar...