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@#Arthropods of medical importance such as mosquitoes, ticks and sandflies are one of the key drivers of arthropod-borne diseases outbreak, posing a great threat to global public health security. For further understanding the transmission mechanisms of arthropod-borne diseases and establishing the prevention and control measures, a series of experiments of arthropods infection need to be carried out under laboratory conditions. Besides the regular biosafety requirements, some specific considerations need to be taken into account when performing arthropod infection and the infected arthropod rearing. Except for the physical containment composed of biosafety facilities, a comprehensive assessment of the biosafety risks during operations and corresponding preventive measures are also critical to eliminate or mitigate the biosafety risks. In this paper, we introduce our practice in handling mosquito infection with Risk Group 2 pathogens in Arthropod Containment Level-2 (ACL-2) laboratory, with an aim to provide a reference for researchers in related fields.
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Objective@#To investigate a cluster of coronavirus disease 2019(COVID-19)caused by latent infection in Haikou,so as to provide reference for the prevention and control of COVID-19 clusters. @*Methods@#An epidemiological investigation was conducted according to the COVID-19 Prevention and Control Program(Fourth Edition). The course of diagnosis and treatment,clinical characteristics and field investigation data were collected to analyze the transmission chain and the intergeneration between cases. @*Results @#Among 39 people involved,five confirmed cases and two asymptomatic infections were found,with an attack rate of 17.95%. The cases aged from 40 to 65 years and lived in the dormitories near the farm of Dongshan. The first case(named Case 1)closely contacted with a confirmed case of COVID-19 in Chengmai from January 28 to February 10,was isolated on February 13 and developed symptoms on February 16. The other six cases(Case 2 to Case 7)shared the water source with Case 1 from January 28 to February 13(within the incubation period of Case 1). They needed to open the power switch outside Case 1's room and the water valve in Case 1's washroom before the use of water. They might be infected by contacting the doorknob and the water valve contacted by Case 1,or by the aerosol formed after Case 1 used the washroom,then infected each other when living together. The onset of Case 2 to Case 7 was earlier than Case 1,and they had no travelling history in Hubei Province 14 days before and contacted no confirmed cases except Case 1. Therefore,Case 1 was the source of the cluster during his incubation period of COVID-19. @*Conclusion@#This was a cluster of COVID-19 due to latent transmission by living in the same area and touching the same objects indirectly,which indicated that COVID-19 was infectious in the incubation period.
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Background. Inhibition of the formation of advanced glycation end-products delays the development of diabetic nephropathy. Puerarin decreases the formation of these products. We studied the effect of puerarin in a rat model of diabetic nephropathy. Methods. Three groups of rats were studied: a control group, a diabetic group in whom diabetic nephropathy was induced by intraperitoneal injection of streptozotocin, and a puerarin group in which diabetic rats were treated with puerarin. During and after treatment, measurements were made on the rats’ general status, blood glucose level, blood urea nitrogen, serum creatinine, creatinine clearance rate and urinary albumin excretion over 24 hours. The expression of collagen I and heparan sulphate proteoglycan in the extracellular matrix of the glomerulus was assessed by immunohistochemistry. Results. Rats in the puerarin group had a better general condition than those with diabetes. They also had lower blood urea nitrogen, serum creatinine and urinary albumin excretion rate over 24 hours compared with those in the diabetic group. The creatinine clearance and expression of heparan sulphate proteoglycan in the kidney also increased significantly in the puerarin group compared with that in the diabetic group. Conclusion. Puerarin seems to have certain protective effects on diabetic nephropathy induced by streptozotocin. This is caused possibly by regulating the expression of glomerular extracellular matrix.