In the outbreak of COVID-19,triage procedures based on epidemiology were implemented in a local hospital in Changsha to control the transmission of SARS-CoV-2 and avoid healthcare-associated infection.This re-trospective study analyzed the data collected during the triage period and found that COVID-19 patients were en-riched 7 folds into the Section A designated for patients with obvious epidemiological history.On the other side,nearly triple amounts of visits were received at the Section B for patients without obvious epidemiological history.8 COVID-19 cases were spotted out of 247 suspected patients.More than 50％of the suspected patients were submi-tted to multiple rounds of nucleic acid analysis for SARS-CoV-2 infection.Of the 239 patients who were diagnosed as negative of the virus infection,188 were successfully revisited and none was reported as COVID-19 case.Of the 8 COVID-19 patients,3 were confirmed only after multiple rounds of nucleic acid analysis.Besides comorbidities,delayed sharing of epidemiological history added complexity to the diagnosis in practice.The triaging experience and strategy will be helpful for the control of infectious diseases in the future.

With the ongoing epidemic of the Coronavirus disease in China and the widespread development of radiotherapy, radiation-induced lung injury has gradually become a clinical problem that has attracted much attention. The pathogenesis of radiation-induced lung injury is complex, involving an imbalance in the polarization state of alveolar macrophages and an upregulation of alveolar epithelial cell apoptosis. Previous studies have shown that vitamin C is an important antioxidant substance, and preventive use of vitamin C can effectively treat acute lung injury. However, whether prophylactic use of vitamin C can effectively prevent or treat lung injury caused by radioactive substances, and its specific molecular mechanism remains to be studied. The purpose of this study is to investigate whether the prophylactic use of vitamin C to treat the alveolar macrophage cell line RAW 264. 7 and human lung epithelial cells BEAS-2B can effectively control the abnormal polarization of macrophages and the abnormal apoptosis of lung epithelial cells. This study found that after 4 weeks and 8 weeks of radioactive X-ray irradiation, the expression of macrophage M1 polarization state markers such as iNOS was significantly up-regulated (P< 0. 05), and preventive use of vitamin C to treat macrophages and lung epithelial cells can alleviate the polarization state disorder of macrophages and the apoptosis of alveolar epithelial cells caused by external radiation exposure, which is manifested in the down-regulation of the expression of Cleaved Caspase3. In addition, the preventive application of vitamin C treatment can inhibit the MAPK signaling pathway activated by external radiation exposure. Further experimental results showed that the inhibition of the MAPK pathway is the key to inhibiting the M1 polarization of macrophages and the apoptosis of lung epithelial cells. In summary, our findings suggest that vitamin C may play a protective role in acute radiation-induced lung injury by inhibiting macrophage M1 polarization/ promoting macrophage M2 polarization and alleviating alveolar epithelial cell apoptosis. This study will help to better understand the process and mechanism of the preventive effect of vitamin C, a common vitamin, on radiation-induced lung injury.

Objective To analyze the genetic subtypes of human immunodeficiency virus (HIV) and the prevalence of pretreatment drug resistance in the newly reported HIV-infected men in Guangxi. Methods The stratified random sampling method was employed to select the newly reported HIV-infected men aged≥50 years old in 14 cities of Guangxi from January to June in 2020.The pol gene of HIV-1 was amplified by nested reverse transcription polymerase chain reaction and then sequenced.The mutation sites associated with drug resistance and the degree of drug resistance were then analyzed. Results A total of 615 HIV-infected men were included in the study.The genetic subtypes of CRF01_AE,CRF07_BC,and CRF08_BC accounted for 57.4% (353/615),17.1% (105/615),and 22.4% (138/615),respectively.The mutations associated with the resistance to nucleoside reverse transcriptase inhibitors (NRTI),non-nucleoside reverse transcriptase inhibitors (NNRTI),and protease inhibitors occurred in 8 (1.3%),18 (2.9%),and 0 patients,respectively.M184V (0.7%) and K103N (1.8%) were the mutations with the highest occurrence rates for the resistance to NRTIs and NNRTIs,respectively.Twenty-two (3.6%) patients were resistant to at least one type of inhibitors.Specifically,4 (0.7%),14 (2.3%),4 (0.7%),and 0 patients were resistant to NRTIs,NNRTIs,both NRTIs and NNRTIs,and protease inhibitors,respectively.The pretreatment resistance to NNRTIs had much higher frequency than that to NRTIs (2.9% vs.1.3%;χ²=3.929,P=0.047).The prevalence of pretreatment resistance to lamivudine,zidovudine,tenofovir,abacavir,rilpivirine,efavirenz,nevirapine,and lopinavir/ritonavir was 0.8%, 0.3%, 0.7%, 1.0%, 1.3%, 2.8%, 2.9%, and 0, respectively. Conclusions CRF01_AE,CRF07_BC,and CRF08_BC are the three major strains of HIV-infected men≥50 years old newly reported in Guangxi,2020,and the pretreatment drug resistance demonstrates low prevalence.
Male ; Humans ; Middle Aged ; Reverse Transcriptase Inhibitors/therapeutic use* ; HIV Infections/drug therapy* ; Drug Resistance, Viral/genetics* ; China/epidemiology* ; Mutation ; HIV-1/genetics* ; Protease Inhibitors/therapeutic use* ; Genotype

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.
COVID-19 ; Cohort Studies ; Contact Tracing ; Humans ; Incidence ; Prospective Studies

CRISP R/Cas9 is an emerging gene editing technique, which plays an important role in life science research.It is of great significance to introduce this cutting-edge scientific technique into the experimental teaching for undergraduates.Therefore, we established an undergraduate experiment system based on CRISPR/Cas9 technology.This experiment system focuses on the application of CRISPR/Cas9- mediating gene editing in mammalian cells.An engineered mouse embryonic fibroblast which genome were inserted with fluorescein mCherry gene was selected as the experimental model, and called STO-82.Firstly, sgRNAs targeting mCherry gene were designed to construct CRISPR-Cas9/sgRNA co-expression plasmids.After being confirmed by sequencing, they were transfected into STO-82 cells.Two groups of cells with mCherry negative and positive signals were detected by fluorescence-activated cell sorting.Single cells with negative fluorescence were separated and then cultivated to become monoclonal cells.The mutation status of mCherry gene in monoclonal cell lines was detected by sequence analysis.The result showed that there were mutations of insertion or deletion at target sites, indicating that the experimental system was successfully established.Therefore, this comprehensive experiment is comprised of sgRNA design, construction of CRISPR-Cas9/sgRNA co-expression plasmids, cell transfection, cell sorting, monoclonal cell cultivation and sequence analysis.This experiment system is used for experimental teaching for senior undergraduates.Teaching practice can either be decomposed into content modules or be taken as a whole program in light of actual situation.In the teaching practice at 3 classes (13 groups in total, two students every group), which adopted the model of small-class teaching (about 10 students per class), the majority completed the content modules and the expected outcomes were achieved.Through the design and teaching practice of this experiment system, the students acquire a deeper understanding for the principle and experimental procedure of CRISPR/Cas9 technology, an enhanced experimental ability and rigorous scientific thinking and also some knowledge in the risk of its medical application.

Objective To investigate the relationship between hemoglobin and blood pressure of pregnant women in Zhoushan islands, so as to provide scientific evidence for the etiological study of gestational hypertension. Methods A retrospective study was conducted among 1 383 pregnant women who received perinatal care in Zhoushan Maternal and Child Health Hospital of Zhejiang Province from January 2017 to June 2018. Pregnant women were monitored for hemoglobin content and blood pressure in the early, middle and late pregnancy. The multivariate linear regression was used to analyze the relationship between hemoglobin content and blood pressure in different pregnancy. Results The incidence of anemia in early, middle and late pregnancy was 7.74%, 25.45% and 15.76% respectively. The multivariate linear regression showed that hemoglobin levels during pregnancy had effects on systolic blood pressure in early, middle and late pregnancy, and the earlier hemoglobin levels were monitored, the more obvious the effect on systolic blood pressure was.With the increase of hemoglobin level, systolic blood pressure increased, such as the effect of hemoglobin on systolic blood pressure in early pregnancy, mid-pregnancy and late pregnancy. Hemoglobin of first trimster had the greatest effect (β=0.10, P<0.001), Hemoglobin of second trimester had no obvious effect, and that of third trimester had the second effect (β=0.04, P=0.027).Hemoglobin levels and diastolic blood pressure levels were similar to their relationship with systolic blood pressure. Conclusions Hemoglobin levels during pregnancy have significant effects on systolic and diastolic blood pressure in first, second and third trimsters of pregnancy. Regular measurement of hemoglobin levels during pregnancy can improve the health of pregnant women.

Realgar nanoparticles (NPs) are increasingly used as therapeutic agents for their enhanced anti-proliferation effect and cytotoxicity on cancer cells. However, the alteration of particle size may enhance biological reactivity as well as toxicity. A LC/MS and GC/MS based metabolomics approach was employed to explore the mechanism of realgar NPs-induced hepatotoxicity and identify potential biomarkers. Male Sprague-Dawley rats were administrated intragastrically with realgar or realgar NPs at a dose of 1.0 g·kg·d for 28 days and toxic effects of realgar NPs on liver tissues were examined by biochemical indicator analysis and histopathologic examination. Increased levels of serum enzymes and high hepatic steatosis were discovered in the realgar NPs treated group. Multivariate data analysis revealed that rats with realgar NPs-induced hepatotoxicity could be distinctively differentiated from the animals in the control and realgar treated groups. In addition, 21 and 32 endogenous metabolites were apparently changed in the serum and live extracts, respectively. Realgar NPs might induce free fatty acid and triglyceride accumulation, resulting in hepatotoxicity. In conclusion, the present study represents the first comprehensive LC/MS- and GC/MS-based metabolomics analysis of realgar NPs-induced hepatotoxicity, which may help further research of nanotoxicity.
Animals ; Biomarkers ; blood ; chemistry ; Chromatography, Liquid ; methods ; Fatty Acids ; metabolism ; Gas Chromatography-Mass Spectrometry ; methods ; Liver ; chemistry ; drug effects ; metabolism ; Male ; Mass Spectrometry ; methods ; Metabolomics ; methods ; Nanoparticles ; toxicity ; Rats ; Rats, Sprague-Dawley ; Triglycerides ; metabolism

Evaluation of the permeability mainly focuses on intestinal absorption in biopharmaceutics classification system (BCS). It is more complicated that the absorption and metabolism under multicomponent environment in biopharmaceutics classification system of Chinese materia medica (CMMBCS) compared with single component environment, which needs suitable mathematical models to be described. Therefore, with full consideration of existing single component mathematical algorithm combining with the characteristics of intestinal absorption and metabolism, we explored and designed a new mathematical algorithm of intestinal absorption and metabolism of multicomponent drug. Then we put forward a new coefficient, P (influence), the relative change rate of the single component's intestinal absorption and metabolism under multicomponent environment compared with single component environment, which described the influences of intestinal absorption and metabolism of the component under multicomponent environment. Moreover, P (influence) highlights the distinctive characteristics of multicomponent drug's intestinal absorption and metabolism, and lays the foundation for the construction of CMMBCS.
Algorithms ; Drugs, Chinese Herbal ; chemistry ; pharmacokinetics ; Humans ; Intestinal Absorption ; Intestines ; chemistry ; metabolism ; Models, Theoretical ; Solubility

AIM: To evaluate the safety and efficacy of intravitreal bevacizumab ( avastin ) injection in patients with exudative age related macular degeneration ( AMD) .
METHODS: The records of patients treated with intravitreal injection of 1. 75mg bevacizumab for AMD were retrospectively reviewed. All patients were evaluated by complete ophthalmic examination, optical coherence tomography and fundus fluorescein and/or indocyanine green angiography. Observation was made on the best corrected visual acuity ( BCVA) , intraocular pressure, and the changes of lens, vitreous, central retinal thickness (CFT) and total macular volume (TMV), at 1d, 3d, 7d, 1mo and 6mo after the treatment and then compared with those of pre - operation. Repeated treatment with intravitreous bevacizumab occurred if there were signs of persistent or recurrent exudation. And all cases were followed up at least 6mo. An intravitreal injection of bevacizumab (1. 75mg) was given once every 6wk.
RESULTS:All 50 eyes of 48 patients with the average of 58±20. 46 years old were included. The mean baseline of BCVA and CFT were 0. 82±0. 53, and 364. 97±151. 83μm respectively. Although there was no significant decrease in mean CFT and TMV one week after the injection, the mean BCVA had significant improvement. At the last visit of 9. 7mo follow - up, BCVA, CRT and TMV showed significant improvements over baseline values. BCVA was improved by at least two lines in 32 eyes (64%),remained stabilization in 18 eyes (36%) at the last visit. A total of 98 injections were performed and the average number of injections was 1. 98 for each eye in the group. About 50%of re - injections gained at least two lines of vision improvement one week postoperatively. There were no serious adverse events during the treatment.
CONCLUSION: Intravitreal bevacizumab ( avastin ) injection for managing CNV due to age-related macular degeneration is safe and few side effects. Intravitreal avastin associated with improvement in visual acuity ( VA ) , which can reduce macular edema and choroidal neovascularization leakage. But a prolonged treatment effect needs further observation.

To evaluate the safety and efficacy of intravitreal bevacizumab injection in patients with macular edema (ME) induced by retinal vein occlusion (RVO).
● METHODS: The records of patients treated with intravitreal injection of 1. 75mg bevacizumab for ME induced by RVO were retrospectively reviewed. All patients were evaluated by complete ophthalmic examination, optical coherence tomography ( OCT) and fundus fluorescein angiography ( FFA ), etc. Best corrected visual acuity (BCVA), intraocular pressure, the change of lens and vitreous, central foveal thickness (CFT) were observed at 1, 2, 3, 6mo after treatment and compared with before treatment. Repeated treatment with intravitreous bevacizumab occurred if there were signs of persistent or recurrent exudation. All the cases were followed up at least 6mo. An intravitreal injection of bevacizumab (1. 75mg) was given at 6wk intervals.
●RESULTS: Fifty patients (56 eyes) with the average of (57±18. 56) years old were included. The mean baseline of BCVA, CFT were (logMAR0. 82±0. 63), (626. 5±178. 0)μm respectively. Although there was no significant decrease in mean CFT at 1wk after injection, the mean BCVA had significant improvement. Followed up at mean 10. 26 ± 5. 87mo, BCVA, CFT showed significant improvements over baseline values. The statistics of CFT at 1, 2, 3mo after injection were significant differences compared with before injection in each of the three groups. CFT at 1, 3, 12mo after injection were (365. 11±23. 212) μ m, (333. 42± 35. 526) μ m, (267. 6 ± 116. 8) μ m, which had a significant difference ( P < 0. 001), namely macular retinal thickness was thinner obviously that before treatment, ME was improved obviously. CFT was no significant difference at each time point after injection in the group of BRVO-ME and CRVO- ME (P> 0. 05). OCT image showed that after injection macular retinal thickness was becoming thinner. FFA showed that after injection macular fluorescein leakage decreased. BCVA was improved by at least two lines in 48 eyes (86%),remained stable in 8 eyes (14%) at the last visit. A total of 112 injections were performed and the average number of injections was 1. 96 in the group. About 50% of reinjections gained at least two lines of vision improvement at 1wk following the retreatment. There was no serious complications during the treatment.
●CONCLUSlON: lntravitreal injection of bevacizumab can improve visual acuity (VA) of RVO (CRVO and BRVO) in patients with ME, relieve ME, reduce the leakage of CNV, and repeated treatment is better. But a prolonged treatment effect needs further observation. There are no serious ocular and systemic complications occurred in our study.