Convalescence from prototype SARS-CoV-2 protects Syrian hamsters from disease caused by the Omicron variant

The mutation profile of the SARS-CoV-2 Omicron variant poses a concern for naturally acquired and vaccine-induced immunity. We investigated the ability of prior infection with an early SARS-CoV-2, 99.99% identical to Wuhan-Hu-1, to protect against disease caused by the Omicron variant. We established that infection with Omicron in naive Syrian hamsters resulted in a less severe disease than a comparable dose of prototype SARS-CoV-2 (Australia/VIC01/2020), with fewer clinical signs and less weight loss. We present data to show that these clinical observations were almost absent in convalescent hamsters challenged with the same dose of Omicron 50 days after an initial infection with Australia/VIC01/2020. The data provide evidence for immunity raised against prototype SARS-CoV-2 being protective against Omicron in the Syrian hamster model. Further investigation is required to conclusively determine whether Omicron is less pathogenic in Syrian hamsters and whether this is predictive of pathogenicity in humans.

Comparison of Rhesus and Cynomolgus macaques as an authentic model for COVID-19.

A novel coronavirus, SARS-CoV-2, has been identified as the causative agent of the current COVID-19 pandemic. Animal models, and in particular non-human primates, are essential to understand the pathogenesis of emerging diseases and to the safety and efficacy of novel vaccines and therapeutics. Here, we show that SARS-CoV-2 replicates in the upper and lower respiratory tract and causes pulmonary lesions in both rhesus and cynomolgus macaques, resembling the mild clinical cases of COVID-19 in humans. Immune responses against SARS-CoV-2 were also similar in both species and equivalent to those reported in milder infections and convalescent human patients. Importantly, we have devised a new method for lung histopathology scoring that will provide a metric to enable clearer decision making for this key endpoint. In contrast to prior publications, in which rhesus are accepted to be the optimal study species, we provide convincing evidence that both macaque species authentically represent mild to moderate forms of COVID-19 observed in the majority of the human population and both species should be used to evaluate the safety and efficacy of novel and repurposed interventions against SARS-CoV-2. Accessing cynomolgus macaques will greatly alleviate the pressures on current rhesus stocks.

Shorter interval between radiation therapy and salvage laryngopharyngeal surgery increases complication rates following microvascular free tissue transfer.

PURPOSE: To evaluate how the interval between radiation and salvage surgery for advanced laryngeal cancer with free tissue transfer reconstruction influences complication rates. MATERIALS AND METHODS: This is a retrospective series of 26 patients who underwent salvage laryngectomy or laryngopharyngectomy with vascularized free tissue reconstruction (anterolateral thigh or radial forearm) following radiation or chemoradiation between 2012 and 2017 at a single academic center. The primary outcome was incidence of postoperative complications, including pharyngocutaneous fistula. Secondary outcomes included the need for a second procedure, time to resumption of oral feeding, feeding tube dependence, and hospital length of stay. RESULTS: Salvage surgery was performed for persistence (7/26, 27%), recurrence/new primary (12/26, 46%), and dysfunctional larynges (7/26, 27%). Twenty-two (85%) defects were reconstructed with an anterolateral thigh free flap and 4/26 with a radial forearm free flap (15%). There were no flap failures. There were significantly more complications in patients undergoing surgery within 12 months of completion of radiation therapy (7/12, 58%) versus those undergoing surgery after 12 months (1/14, 7%; p = .02). Patients experiencing complications more often required a second procedure (4/7 vs. 0/1; p = .02), experienced a longer delay to initiation of oral diet (61 vs. 21 days; p = .04), and stayed in the hospital longer (28 vs. 9 days; p = .01). CONCLUSIONS: Shorter intervals between definitive radiation and salvage laryngopharyngeal surgery with free tissue reconstruction increases postoperative complications, hospital length of stay, and the likelihood of feeding tube dependence. Reconstructive surgeons can use these findings to help guide preoperative patient counseling and assess postoperative risk.

Hyperostotic Esthesioneuroblastoma: Rare Variant and Fibrous Dysplasia Mimicker

A 65-year-old male presented with a 3-year history of orbital symptoms. An imaging-based diagnosis of fibrous dysplasia involving the skull base was made at another institution. CT showed a diffuse sinonasal mass and ground-glass appearance of the bones of the anterior skull base with bony defects and mucocele formation. MRI demonstrated an accompanying intracranial and orbital rind of soft tissue mass along the hyperostotic bones. FDG-PET showed corresponding intense hypermetabolism. Small cysts were observed at the tumor-brain interface. Biopsy revealed esthesioneuroblastoma with bone infiltration that is compatible with the hyperostotic variant of esthesioneuroblastoma. There are a few cases of hyperostotic esthesioneuroblastoma reported in the literature.

Reconstruction of a tracheobronchial tree disruption with bovine pericardium.

Iatrogenic tracheobronchial disruption is a rare, life-threatening condition. Depending upon the extent of the injury, its location, and the condition of the patient, repair/reconstruction options may be limited. The natural history of bovine pericardium used to repair one such tracheal injury has been documented.