BACKGROUND:Molecular stability and biocompatibility of hemerythrin surpass those of human and mammalian hemoglobin,making it a potential candidate for a safer and more effective erythrocyte substitute after modification.OBJECTIVE:To prepare multi-modified hemerythrin nanoparticles,characterize them,and test their performance in vitro.METHODS:The hemerythrin of Sipunculus sphenodontus was separated and purified by tangential flow ultrafiltration.The intramolecular cross-linking was completed by genipin.The nanoparticles were encapsulated by dopamine,and passivated by polyethylene glycol to obtain multi-modified hemerythrin nanoparticles.The physicochemical properties of the nanoparticles were characterized.Hemerythrin nanoparticles,hemerythrin,and hemoglobin oxygen carrier HBOC-201 with different mass concentrations(0,0.25,0.5,1.0,and 2.0 mg/mL)were incubated with macrophages for 6 and 24 hours,and with endothelial cells for 24 hours.The cell survival rate was detected by CCK-8 assay.The levels of nitric oxide and vascular cell adhesion factor 1 in the culture medium of endothelial cells were detected by ELISA.RESULTS AND CONCLUSION:(1)Under electron microscopy,hemerythrin nanoparticles were ellipsoidal,with a dense outer membrane and a relatively uniform internal texture.The particle size was(150.12±1.67)nm;the dispersion index was 0.21±0.03;the Zeta potential was(-24.54±2.61)mV;the half-saturated oxygen partial pressure was(0.97±0.15)kPa,and the Hill coefficient was 1.49±0.16.(2)After incubation for 6 hours,within the mass concentration range of≤1.0 mg/mL,the survival rates of macrophages in the hemerythrin nanoparticle group,the hemerythrin group,and the HBOC-201 group were all above 85%.At a mass concentration of 2.0 mg/mL,only the survival rate of macrophages in the hemerythrin nanoparticle group was above 80%.After incubation for 24 hours,the survival rates of macrophages in the three groups were all lower than 80%,among which the survival rate of macrophages in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and the HBOC-201 group(P<0.05).(3)With the increase of drug concentration,the survival rate of vascular endothelial cells in the three groups decreased.At 1.0 mg/mL or 2.0 mg/mL mass concentration,the survival rate of cells in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).At the same mass concentration,the nitric oxide level in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).In the range of 0.25-2.0 mg/mL mass concentration,the vascular cell adhesion factor 1 level in the hemerythrin nanoparticle group was lower than that in the hemerythrin group and HBOC-201 group(P<0.05).(4)The results showed that the hemerythrin nanoparticles modified with intramolecular cross-linking and polydopamine/polyethylene glycol had good oxygen-carrying activity in vitro,better anti-phagocytic performance,and less cytotoxicity.

BACKGROUND:Molecular stability and biocompatibility of hemerythrin surpass those of human and mammalian hemoglobin,making it a potential candidate for a safer and more effective erythrocyte substitute after modification.OBJECTIVE:To prepare multi-modified hemerythrin nanoparticles,characterize them,and test their performance in vitro.METHODS:The hemerythrin of Sipunculus sphenodontus was separated and purified by tangential flow ultrafiltration.The intramolecular cross-linking was completed by genipin.The nanoparticles were encapsulated by dopamine,and passivated by polyethylene glycol to obtain multi-modified hemerythrin nanoparticles.The physicochemical properties of the nanoparticles were characterized.Hemerythrin nanoparticles,hemerythrin,and hemoglobin oxygen carrier HBOC-201 with different mass concentrations(0,0.25,0.5,1.0,and 2.0 mg/mL)were incubated with macrophages for 6 and 24 hours,and with endothelial cells for 24 hours.The cell survival rate was detected by CCK-8 assay.The levels of nitric oxide and vascular cell adhesion factor 1 in the culture medium of endothelial cells were detected by ELISA.RESULTS AND CONCLUSION:(1)Under electron microscopy,hemerythrin nanoparticles were ellipsoidal,with a dense outer membrane and a relatively uniform internal texture.The particle size was(150.12±1.67)nm;the dispersion index was 0.21±0.03;the Zeta potential was(-24.54±2.61)mV;the half-saturated oxygen partial pressure was(0.97±0.15)kPa,and the Hill coefficient was 1.49±0.16.(2)After incubation for 6 hours,within the mass concentration range of≤1.0 mg/mL,the survival rates of macrophages in the hemerythrin nanoparticle group,the hemerythrin group,and the HBOC-201 group were all above 85%.At a mass concentration of 2.0 mg/mL,only the survival rate of macrophages in the hemerythrin nanoparticle group was above 80%.After incubation for 24 hours,the survival rates of macrophages in the three groups were all lower than 80%,among which the survival rate of macrophages in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and the HBOC-201 group(P<0.05).(3)With the increase of drug concentration,the survival rate of vascular endothelial cells in the three groups decreased.At 1.0 mg/mL or 2.0 mg/mL mass concentration,the survival rate of cells in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).At the same mass concentration,the nitric oxide level in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).In the range of 0.25-2.0 mg/mL mass concentration,the vascular cell adhesion factor 1 level in the hemerythrin nanoparticle group was lower than that in the hemerythrin group and HBOC-201 group(P<0.05).(4)The results showed that the hemerythrin nanoparticles modified with intramolecular cross-linking and polydopamine/polyethylene glycol had good oxygen-carrying activity in vitro,better anti-phagocytic performance,and less cytotoxicity.

ObjectiveTo observe the effectiveness and safety of the Chinese herbal medicine Mingshi Granules （明视方颗粒） for low myopia in children with heart yang insufficiency. MethodsA multicentre， prospective， double-blind randomised controlled study was conducted， in which 290 children with low myopia from 8 centres were randomly divided into 145 cases in the treatment group and 145 cases in the control group， and the treatment group was given education， dispensing glasses， and Chinese herbal medicine Mingshi Granules， while the control group was given education， dispensing glasses， and granules placebo. Both Mingshi Granules and placebo granules were taken orally， 1 bag each time， twice daily， 4 weeks of oral intake and 2 weeks of rest as 1 course of treatment， a total of 4 courses of treatment （24 weeks）. Equivalent spherical lenses， best naked-eye distance visual acuity， ocular axis， corneal curvature K1， adjustment amplitude， traditional Chinese medicine （TCM） symptom scores， calculate the amount of progression of equivalent spherical lenses， were observed at the 12th and the 24th week of treatment， at the 36th week and 48th week of follow-up， resectively， the control rate of myopia progression was evaluated at the 24th week， and safety indexes were observed before treatment. ResultsThe amount of progression of equivalent spherical lenses was lower in the treatment group than in the control group at the 48-week follow-up （P＜0.05）. The control rate of myopia progression at 24 weeks after treatment in the treatment group was higher （57.60%， 72/125） than that in the control group （44.63%， 54/121） （P＜0.05）. The best naked-eye distance visual acuity at 36-week follow-up in the treatment group was higher than that in the control group （P＜0.05）. Equivalent spherical lenses were significantly lower in both groups at all observation time points compared with pre-treatment （P＜0.05）， and were higher in the treatment group than in the control group at the 48-week follow-up （P＜0.05）. The ocular axes of both groups were significantly higher at each observation time point after treatment and at follow-up compared with before treatment （P＜0.05）. The amount of eye axis growth in the treatment group was lower than that in the control group at 24 weeks after treatment and at the 48-week follow-up （P＜0.05）. Corneal curvature K1 was significantly lower in the treatment group at the 24th week of treatment compared to pre-treatment （P＜0.05）. The magnitude of adjustment in the treatment group was significantly higher at the 36-week follow-up and at the 48-week follow-up than before treatment （P＜0.05）. The scores of white/dark complexion， white coating thin pulse， fatigue and total TCM symptom scores of children in both groups at the 12th， 24th， 36th and 48th weeks of follow-up were significantly lower than those before treatment （P＜0.05）； the scores of blurred vision at the 24th and 36th weeks of follow-up were significantly lower than those before treatment （P＜0.05）； and the scores of blurred vision in the treatment group at the 48th week of follow-up were signi-ficantly lower than those before treatment （P＜0.05）. In the treatment group， the score of fatigue was higher than that of the control group at the 36-week follow-up， and the score of blurred vision was lower than that of the control group at the 48-week follow-up （P＜0.05）. No adverse reactions or obvious abnormalities of the safety indexes were observed of the two groups during the treatment. ConclusionChinese herbal medicine Mingshi Granules showed the effect of controlling the progression of low myopia， improving the best naked eye distance visual acuity， slowing down the growth of the eye axis， improving some of the TCM symptoms， with good safety.

Chronic kidney disease (CKD) is a serious health problem worldwide, whereas there is still no efficient cure. The gut microbiota plays a crucial role in maintaining human health and disease resistance, and multiple studies have confirmed that the gut microbiota is closely related to the occurrence and development of CKD. Starting from the "gut-kidney axis" theory, this article provides a systematic review of the changes in gut microbiota composition and function in patients with CKD, such as a decrease in the abundance of butyrate-producing bacteria Roseburia and Faecalibacterium prausnitzii. Besides that, the article explores the mechanisms by which the gut microbiota affects CKD progression, such as inflammation and immunity, and also describes the application methods of using the gut microbiota as a therapeutic target for CKD, such as fecal microbiota transplantation, microecologics, and dietary therapy, in order to provide microbial- based targets for the clinical diagnosis and treatment of CKD.

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.
Humans ; Tooth Movement Techniques/adverse effects* ; Root Resorption/etiology* ; Consensus ; Dental Cementum ; Risk Factors

Objective To compare the epidemiological characteristics of COVID-19 in Guangzhou and Wenzhou, and evaluate the effectiveness of their prevention and control measures. Methods Data of COVID-19 cases reported in Guangzhou and Wenzhou as of 29 February, 2020 were collected. The incidence curves of COVID-19 in two cities were constructed. The real time reproduction number ( R t ) of COVID-19 in two cities was calculated respectively. Results A total of 346 and 465 confirmed COVID-19 cases were analysed in Guangzhou and Wenzhou, respectively. In two cities, most cases were aged 30-59 years (Guangzhou: 54.9%; Wenzhou: 70.3%). The incidence curve peaked on 27 January, 2020 in Guangzhou and on 26 January, 2020 in Wenzhou, then began to decline in both cities. The peaks of imported COVID-19 cases from Hubei occurred earlier than the peak of COVID-19 incidences in two cities, and the peak of imported cases from Hubei occurred earlier in Wenzhou than in Guangzhou. In early epidemic phase, imported cases were predominant in both cities, then the number of local cases increased and gradually took the dominance in Wenzhou. In Guangzhou, the imported cases was still predominant. Despite the different epidemic pattern, the R t and the number of COVID-19 cases declined after strict prevention and control measures were taken in Guangzhou and in Wenzhou. Conclusion The time and scale specific differences of imported COVID-19 resulted in different epidemic patterns in two cities, but the spread of the disease were effectively controlled after taking strict prevention and control measures.

Objective To assess the imported risk of COVID-19 in Guangdong province and its cities, and conduct early warning. Methods Data of reported COVID-19 cases and Baidu Migration Index of 21 cities in Guangdong province and other provinces of China as of February 25, 2020 were collected. The imported risk index of each city in Guangdong province were calculated, and then correlation analysis was performed between reported cases and the imported risk index to identify lag time. Finally, we classified the early warming levels of epidemic by imported risk index. Results A total of 1 347 confirmed cases were reported in Guangdong province, and 90.0% of the cases were clustered in the Pearl River Delta region. The average daily imported risk index of Guangdong was 44.03. Among the imported risk sources of each city, the highest risk of almost all cities came from Hubei province, except for Zhanjiang from Hainan province. In addition, the neighboring provinces of Guangdong province also had a greater impact. The correlation between the imported risk index with a lag of 4 days and the daily reported cases was the strongest (correlation coefficient: 0.73). The early warning base on cumulative 4-day risk of each city showed that Dongguan, Shenzhen, Zhongshan, Guangzhou, Foshan and Huizhou have high imported risks in the next 4 days, with imported risk indexes of 38.85, 21.59, 11.67, 11.25, 6.19 and 5.92, and the highest risk still comes from Hubei province. Conclusions Cities with a large number of migrants in Guangdong province have a higher risk of import. Hubei province and neighboring provinces in Guangdong province are the main source of the imported risk. Each city must strengthen the health management of migrants in high-risk provinces and reduce the imported risk of Guangdong province.

Objective:Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province.Methods:The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared.Results:A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M( P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant ( P=0.003). Conclusion:COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

Objective:Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province.Methods:The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared.Results:A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M( P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant ( P=0.003). Conclusion:COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

Objective To test and evaluate the JAK2 gene V617F mutation in patients with myeloproliferative tumors based on i-densy IS-5320 platform according to ISO15189 accreditation requirements.Methods Instrument performance verification.Selected from December 2014 to February 2017, 20 cases of JAK2 V617F mutation positive peripheral blood samples from Huashan Hospital of the Shanghai FuDan University Medical College and 20 cases of peripheral blood samples with negative JAK2V617F mutation.The Realtime PCR with TaqMan MGB probe was selected as the control method to verify and evaluate the accuracy of testing JAK 2 V617F mutation on i-densy IS-5320 platform.Whole blood samples were used to evaluate the reproducibility , cross-contamination and anti-interference ability of this platform.The ability of mutation load was verified by detecting mixtures of human erythnoleukemia cells and colorectal cancer cell HCT116 with 12 different proportions.Results I-densy IS-5320 platform and TaqMan MGB probe real-time fluorescence quantitative PCR show the same result .The within-run reproducibility and between-run reproducibility are both 100%.There is no observed contamination .High bilirubin and high triglyceride blood samples have no obvious interference on mutation detection .The mutation ratio with a load as low as 0.25%could be tested stably by i-densy IS-5320 platform.The detecting peak of melting curve can reflect the ratio of JAK2 V617F mutation to some extent.Conclusions I-densy IS-5320 can detect the mutation of JAK2 V617F gene in the whole blood directly.It has high sensitivity, accuracy and stability, and is easy to operate, and also can reflect the mutation load of JAK2 V617F, which could meet the clinical requirements for the detection of mutations.