Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for an unprecedented global pandemic of COVID-19. Animal models are urgently needed to study the pathogenesis of COVID-19 and to screen vaccines and treatments. We show that African green monkeys (AGMs) support robust SARS-CoV-2 replication and develop pronounced respiratory disease, which may more accurately reflect human COVID-19 cases than other nonhuman primate species. SARS-CoV-2 was detected in mucosal samples, including rectal swabs, as late as 15 days after exposure. Marked inflammation and coagulopathy in blood and tissues were prominent features. Transcriptome analysis demonstrated stimulation of interferon and interleukin-6 pathways in bronchoalveolar lavage samples and repression of natural killer cell-and T cell-associated transcripts in peripheral blood. Despite a slight waning in antibody titers after primary challenge, enhanced antibody and cellular responses contributed to rapid clearance after re-challenge with an identical strain. These data support the utility of AGM for studying COVID-19 pathogenesis and testing medical countermeasures.

12Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for an unprecedented global 13 pandemic of COVID-19. Animal models are urgently needed to study the pathogenesis of COVID-19 and to 14 screen candidate vaccines and treatments. Nonhuman primates (NHP) are considered the gold standard model 15 for many infectious pathogens as they usually best reflect the human condition. Here, we show that African green 16 monkeys support a high level of SARS-CoV-2 replication and develop pronounced respiratory disease that may 17 be more substantial than reported for other NHP species including cynomolgus and rhesus macaques. In 18 addition, SARS-CoV-2 was detected in mucosal samples of all animals including feces of several animals as late 19 as 15 days after virus exposure. Importantly, we show that virus replication and respiratory disease can be 20 produced in African green monkeys using a much lower and more natural dose of SARS-CoV-2 than has been 21 employed in other NHP studies. 42varying degrees of non-lethal illness when the virus was delivered into the respiratory tract of these animals [7-43 13]. While each of these models has utility in the study of COVID-19, NHPs have the closest physiological 44 resemblance to humans allowing a better comparison of host responses to infection. This genetic similarity has 45 also contributed to the increased availability of reagents to perform in-depth analyses of the immune response. 46Recently, the first studies evaluating the pathogenic potential of SARS-CoV-2 in cynomolgus and rhesus 47 macaques were performed. Rhesus macaques developed pneumonia and clinical signs whereas disease in 48 cynomolgus macaques was fairly mild indicating the former appears to better reflect more severe cases of 49 . These results suggest certain NHP species may serve as better models than others for 50 4 coronavirus infections. For SARS, the disease caused by SARS-CoV-1, African green monkeys (AGMs) were 51 found to support the highest level of viral replication, followed by cynomolgus macaques and rhesus macaques 52 when all three species were challenged in parallel [14]. Only AGMs had notable replication in the lower 53 respiratory tract following SARS-CoV-1 inoculation; necropsy of these animals indicated focal interstitial 54 mononuclear inflammatory infiltrates and edema in the lung consistent with human SARS. As SARS-CoV-1 and 55 SARS-CoV-2 share the same putative host receptor angiotensin-converting enzyme 2 (ACE2) [15, 16], we 56 reasoned that AGMs might serve as a useful model for COVID-19. 57Here, we infected AGMs with a low passage isolate of SARS-CoV-2 (SARS-CoV-2/INMI1- 58Isolate/2020/Italy) and evaluated their potential as a model for COVID-19. SARS-CoV-2/INMI1-Isolate/2020/Italy 59 was isolated from the first clinical case in Italy [17] and is the first V clade virus (GISAID) to be experimentally 60 inoculated into NHPs. We demonstrate AGMs mimic several aspects of human disease including a high degree 61 of viral replication and severe pulmonary lesions. T...

We sought to report a central T2 hypointensity within the optic nerve on 3 T MRI studies obtained as part of the NASA Flight Medicine Visual Impairment Intracranial Pressure Protocol that had not been described previously. Twenty-one astronauts, who had undergone MRI of both orbits with direct coronal T2 sequences between 2010 and 2012, were retrospectively included. Two of the astronauts did not have previous exposure to microgravity at the time of their scans. A central T2 hypointensity was observed in 100% of both right and left eyes. It was completely visualized throughout the nerve course in 15 right eyes (71.4%) and in 19 left eyes (90.5%).We describe a new finding seen in all study participants: a central T2 hypointensity in the epicenter of the optic nerve. We speculate that this T2 hypointensity may represent flow voids caused by the central retinal vessels.

First described in 1909, giant cell glioblastoma (GC) is a histologic variant of glioblastoma multiforme (GBM) that accounts for 1% of cases of primary GBM. It is characterized by a predominance of bizarre giant cells with abundant eosinophilic cytoplasm, and may portend an improved prognosis over classic GBM. Due to the rarity of GC, there is a paucity of reports that describe its associated radiologic findings. This case report chronicles the progression of a GC that was incidentally discovered in a 74-year-old male with coincident subdural hematoma and empyema. Serial brain imaging was obtained as part of this patient's continued work-up that documents the radiologic characteristics of the GC over a period of months. To our knowledge, this manuscript is the most extensive radiologic documentation of the progression of GC to date.

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