Specialization for Cell-Free or Cell-to-Cell Spread of BAC-Cloned Human Cytomegalovirus Strains Is Determined by Factors beyond the UL128-131 and RL13 Loci.

It is widely held that clinical isolates of human cytomegalovirus (HCMV) are highly cell associated, and mutations affecting the UL128-131 and RL13 loci that arise in culture lead to the appearance of a cell-free spread phenotype. The bacterial artificial chromosome (BAC) clone Merlin (ME) expresses abundant UL128-131, is RL13 impaired, and produces low infectivity virions in fibroblasts, whereas TB40/e (TB) and TR are low in UL128-131, are RL13 intact, and produce virions of much higher infectivity. Despite these differences, quantification of spread by flow cytometry revealed remarkably similar spread efficiencies in fibroblasts. In epithelial cells, ME spread more efficiently, consistent with robust UL128-131 expression. Strikingly, ME spread far better than did TB or TR in the presence of neutralizing antibodies on both cell types, indicating that ME is not simply deficient at cell-free spread but is particularly efficient at cell-to-cell spread, whereas TB and TR cell-to-cell spread is poor. Sonically disrupted ME-infected cells contained scant infectivity, suggesting that the efficient cell-to-cell spread mechanism of ME depends on features of the intact cells such as junctions or intracellular trafficking processes. Even when UL128-131 was transcriptionally repressed, cell-to-cell spread of ME was still more efficient than that of TB or TR. Moreover, RL13 expression comparably reduced both cell-free and cell-to-cell spread of all three strains, suggesting that it acts at a stage of assembly and/or egress common to both routes of spread. Thus, HCMV strains can be highly specialized for either for cell-free or cell-to-cell spread, and these phenotypes are determined by factors beyond the UL128-131 or RL13 loci.IMPORTANCE Both cell-free and cell-to-cell spread are likely important for the natural biology of HCMV. In culture, strains clearly differ in their capacity for cell-free spread as a result of differences in the quantity and infectivity of extracellular released progeny. However, it has been unclear whether "cell-associated" phenotypes are simply the result of poor cell-free spread or are indicative of particularly efficient cell-to-cell spread mechanisms. By measuring the kinetics of spread at early time points, we were able to show that HCMV strains can be highly specialized to either cell-free or cell-to-cell mechanisms, and this was not strictly linked the efficiency of cell-free spread. Our results provide a conceptual approach to evaluating intervention strategies for their ability to limit cell-free or cell-to-cell spread as independent processes.

Significant impact of transperineal template biopsy of the prostate at a single tertiary institution.

OBJECTIVE: The objective was to review the impact of transperineal biopsy (TPB) at our institution by assessing rates of cancer detection/grading, treatment outcomes and complications. PATIENTS AND METHODS: A retrospective review of TPBs between 2009 and 2013 was performed. Variables included reason for TPB, age, prostate-specific antigen, previous histology, TPB histology, and management outcomes. RESULTS: In total, 110 patients underwent 111 TPBs at our institution. On average, 22 cores were taken from each procedure. Disease-upgrade occurred in 37.5% of active surveillance patients, 35% of patients with previous negative transrectal ultrasound, and 58.8% in patients undergoing TPB for other reasons. Of these patients, anterior and/or transition zones were involved in 66%, 79%, and 80%, respectively. Involvement in anterior and/or transition zones only occurred in 40%, 37%, and 10%, respectively. About 77% of patients with disease-upgrading underwent treatment with curative intent. Complications included a 6.3% rate of acute urinary retention and 2.7% of clot retention, with no episodes of urosepsis. CONCLUSIONS: Transperineal biopsy at our institution showed a high rate of disease-upgrading, with a large proportion involving anterior and transition zones. A significant amount of patients went on to receive curative treatment. TPB is a valuable diagnostic procedure with minimal risk of developing urosepsis. We believe TBP should be offered as an option for all repeat prostate biopsies and considered as an option for initial prostate biopsy.

Thyrotoxicosis does not protect against incidental papillary thyroid cancer.

BACKGROUND: Thyroid cancer is the 10th most commonly diagnosed cancer in Australia, and many studies have linked thyroid-stimulating hormone (TSH) and papillary thyroid cancer (PTC). Low TSH is thought to be protective against thyroid cancer. Our aim was to evaluate the relationship between thyrotoxicosis, in particular Graves' disease, and the incidence of incidental PTC. METHODS: After ethics approval, a review of the thyroid database at Monash University Endocrine Surgery Unit was performed. Data was obtained for the period September 1994 to August 2012 and identified those patients who underwent total thyroidectomy (n = 1,898). Those patients with known or suspected malignancy were excluded from the study (n = 390). The remaining patients (n = 1,508) were divided into 3 groups: Graves' disease (n = 250), toxic multinodular goiter (MNG; n = 295), and nontoxic MNG (n = 963) based on indication for surgery and thyroid status. Data were analyzed for the presence of malignancy in each group. RESULTS: Of the 1,508 patients included in the study, 96 (6.4%) had thyroid cancer, and the incidence of PTC was similar between the 3 groups. There were 16 cases (6.4%) in the Graves' group, 48 cases (5%) in the nontoxic MNG group, and 20 cases (6.8%) in the toxic MNG group (P = .41). CONCLUSION: The incidence of malignancy, particularly PTC, is similar in patients with Graves' disease, toxic MNG, and nontoxic MNG. This study demonstrates no protective effect of thyrotoxicosis on the incidence of incidental thyroid cancer.