Purpose: We report a case of idiopathic chiasmal optic neuritis in a pediatric patient.Case summary: A 13-year-old boy with no history of systemic disease was referred to our ophthalmology clinic because of visual disturbance in both eyes of 5 days in duration. The best-corrected visual acuity was 0.08 in the right eye and finger counting at 30 cm in the left eye; mild blurring of the disc margins (both eyes) was evident on fundus examination, as were temporal hemianopsia in the right eye and diffuse field loss in the left eye. Brain magnetic resonance imaging revealed focal nodular enhancement in the optic chiasm. Blood and cerebral fluid analysis yielded no evidence of infection or autoimmune disease. Therefore, we diagnosed isolated idiopathic chiasmal optic neuritis and commenced a systemic steroid. After 5 days, the visual acuity began to improve, and the field defect was almost eliminated (except for a small central scotoma) at 1 month. He has remained stable to the time of writing (4 months after treatment) and his visual acuity has normalized. Conclusions Isolated idiopathic chiasmal optic neuritis developed in a pediatric patient and the visual function improved after steroid treatment. Although there was no evidence of systemic demyelinating disease, regular observation is scheduled given the possibility of late-onset disease.

Purpose: This study analyzed the increase in disposal rate of femoral heads in the bone bank of a single hospital from medical disease and drug history, as assessed by the Korean health insurance review and assessment service. Materials and Methods: The disposal rate and cause of 340 femoral heads were analyzed according to the regulations of the bone bank based on the standard model of the Ministry of food and drug safety. Results: One hundred and seven (33%) of 323 femoral heads collected from 2009 to 2018, and 65 (46%) of 142 femoral heads collected from 2015 to 2018 were discarded. The most common causes were related to the history of dementia and the administration of radioisotope for nuclear medicine. Conclusion The current methods and screening tools can lead to errors in disposing of the available tissues in a bone bank. Thus, improved standards and screening methods are needed.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.