Objective To study the clinical,endoscopic an d pathologic features of primary gastric malignant lymphoma,and to improve its diagnostic efficiency.Methods The clinical,pathologic and endoscopic data in twenty two cases of primary gastric malignant lymphoma were retrospectively reviewed. Results In these cases,the common presentations include abdomi nal pain、anorexia、loss of weight etc. These patients were all examined by endo scopy with protruding,ulcerative and infiltrative lesions. Submucosal lesions w ith hypo echoes were found by endoscopic ultrasonography in six cases,and enlar ged lymph nodes were found on the exterior of stomach in two cases. Conclusion The primary gastric malignant lymphoma has a rather low incidence,and without specific clinical manifestations, hard to differentia te gastric ulcer from cancer through the manifestation in endoscopy. Further com bination of endoscopy, endoscopic ultrasonography and pathology are helpful to i ts correct diagnosis.

Coronavirus disease 2019 (COVID-19), caused by the 2019 novel coronavirus (2019-nCoV), is spreading on a large scale in China. COVID-19 mainly affects the respiratory system and cause symptoms such as severe hypoxemia and high fever. At present, there is no specific treatment drug, and patients' autoimmunity is closely related to disease prognosis. The brain tissue of patients with moyamoya disease is in a state of ischemia and hypoxia for a long time. Hypoxemia and high fever will aggravate the cerebral ischemia and hypoxia in patients with moyamoya disease, and patients with moyamoya disease may also have autoimmune abnormalities. Because people with moyamoya disease are also likely to have COVID-19 and COVID-19 can cause many conditions that may aggravate the symptoms of patients with moyamoya disease, which brings new problems and challenges to the clinical diagnosis and treatment of moyamoya disease. In this article, the diagnosis and treatment process and prevention and control measures of patients with moyamoya disease under the current epidemic situation are thought, and the key issues in the treatment of patients with moyamoya disease after suffering from COVID-19 are sorted out. It is hoped to provide reference for the diagnosis and treatment of moyamoya disease under the COVID-19 epidemic situation.

Objective:To investigate the correlation between RNF213 gene p. R4810K polymorphism and posterior cerebral artery involvement in Chinese children with familial moyamoya disease.Methods:Children with familial moyamoya disease admitted to the Department of Neurosurgery, the Fifth Medical Center of PLA General Hospital from August 2004 to June 2018 were enrolled, and they were divided into posterior cerebral artery involved group and posterior cerebral artery uninvolved group. RNF213 gene p. R4810K single nucleotide polymorphism was detected. Multivariate logistic regression analysis was used to determine the independent risk factors for posterior cerebral artery involvement. Results:A total of 65 children with familial moyamoya disease were enrolled. Their age was 6.98±4.46 years and 37 (56.9%) were male. The first symptom of 55 children (84.6%) was cerebral ischemia, and 37 (56.9%) involved posterior cerebral artery. There were 3 (4.6%) children with p. R4810K AA genotype, 26 (40.0%) with GA genotype, and 36 (55.4%) with GG genotype. The p. R4810K genotype distribution in the posterior cerebral artery involved group was statistically different from that in the uninvolved group (GA+ AA genotype: 56.8% vs. 28.6%; χ2=5.124, P=0.024), and there were no statistical difference in gender, age, first symptom, and genetic pattern. Multivariate logistic regression analysis showed that after adjusting the first onset age and gender, p. R4810K G>A mutation was the only independent risk factor for posterior cerebral artery involvement (odds ratio 3.240, 95% confidence interval 1.082-9.705; P=0.020). Conclusion:The p. R4810K polymorphism of RNF213 gene is associated with posterior cerebral artery involvement in Chinese children with familial moyamoya disease.