Peripheral osteoma of the mandible in a cat

A six-year-old, male, castrated domestic shorthair cat was presented for evaluation of an oral mass. Full physical examination revealed a large hard mass arising from the lateral aspect of the caudal part of the left mandible. Abdominal ultrasound and thoracic computed tomography (CT) were performed to rule out metastatic disease. In addition, CT of the skull with intravenous contrast agent was performed. Histopathological examination of extra- oral biopsies confirmed the tentative diagnosis of peripheral osteoma. A three-dimensional printed skull was used in conjunction with the CT images to determine the detailed location and extent of the mass and to identify anatomical spatial relationships with important neurovascular structures. Surgical debulking of the osteoma was performed. The cat recovered uneventfully but the mass regrew nine months after debulking therapy, sooner than expected. Nevertheless, CT scan of the skull was suggestive for regrowth of the peripheral osteoma rather than for malignant transformation. The owners did not elect to pursue caudal mandibulectomy

Broadly Neutralizing Alphavirus Antibodies Bind an Epitope on E2 and Inhibit Entry and Egress

SummaryWe screened a panel of mouse and human monoclonal antibodies (MAbs) against chikungunya virus and identified several with inhibitory activity against multiple alphaviruses. Passive transfer of broadly neutralizing MAbs protected mice against infection by chikungunya, Mayaro, and O’nyong’nyong alphaviruses. Using alanine-scanning mutagenesis, loss-of-function recombinant proteins and viruses, and multiple functional assays, we determined that broadly neutralizing MAbs block multiple steps in the viral lifecycle, including entry and egress, and bind to a conserved epitope on the B domain of the E2 glycoprotein. A 16 Å resolution cryo-electron microscopy structure of a Fab fragment bound to CHIKV E2 B domain provided an explanation for its neutralizing activity. Binding to the B domain was associated with repositioning of the A domain of E2 that enabled cross-linking of neighboring spikes. Our results suggest that B domain antigenic determinants could be targeted for vaccine or antibody therapeutic development against multiple alphaviruses of global concern