RESUMO
Objective:To observe the epidemiological characteristics and transmission chain of COVID-19 in Harbin, and to provide epidemiological evidence for improving the COVID-19 preventive measures and optimizing prevention and control strategies.Methods:The epidemic situation of COVID-19 in Harbin in January 2021 was analyzed by using the Infectious Disease Report Information Management System and the Public Health Emergency Management Information System of the China Disease Prevention and Control Information System, the epidemic situation information publicly released by the Heilongjiang Provincial Health Commission, and the epidemiological report of Heilongjiang Province Certer for Disease Control and Prevention and Harbin Center for Disease Control and Prevention. The main transmission chains were sorted out through combination of epidemiological field investigation, serological testing, gene sequencing, big data and other means.Results:From January 12 to February 4, 2021, 295 cases of COVID-19 infection (including confirmed cases and asymptomatic infections) were reported in Harbin, which affected 6 districts of Harbin and were concentrated in 41 of the 274 townships in the city. The sex ratio of male to female was 1.00∶1.12 (139∶156); the age ranged from 1 to 86 years old, and the median age was 45 years old. The proportion of confirmed cases and asymptomatic infection was 1.00 ∶ 1.02 (146 ∶ 149), and there was a significant difference in the distribution of different ages between them ( P = 0.042). The cases were mainly found through the health screening of the centralized isolation personnel (178 cases, 60.3%). Other detection methods included active screening (87 cases, 29.5%), screening of the home isolation personnel (26 cases, 8.8%), and medical treatment in medical institutions (4 cases, 1.4%). The main transmission chain of the outbreak was the case associated with a food processing enterprise, with a total of 259 cases, accounting for 87.8% of the total cases. The gene sequencing results showed that the case sequence was homologous with that of Wangkui County, Suihua City, Heilongjiang Province. Conclusions:A food processing enterprise is involved in the main transmission chain, which indicates that the epidemic prevention and control measures needs to be further optimized. Specifically, the supervision and management of food processing enterprises, cold chain storage companies and other enterprises should be strengthened. High attention should be paid to the hidden dangers of COVID-19 in large and medium sized enterprises with hermetic space in Harbin.
RESUMO
Based on the general goal of the medium and long term development of basic science from 2021 to 2035 and the "14th Five-Year Plan" in China, combined with the national strategic needs, this paper discusses the five priority development areas of endemiology according to the development trends and characteristics of endemiology in the next 5 - 15 years. The five areas are study on the pathogenesis and prevention measures of endemic fluorosis; study on risk assessment, pathogenic mechanism and control strategy of environmental arsenic exposure; research on the basis and application transformation of the pathogenesis of iodine nutrition-related diseases; molecular mechanism and targeted intervention of cartilage injury in Kashin-Beck disease; precise prevention and treatment, preservation of biological samples and etiology study of Keshan disease. Combined with the scientific significance and national strategic needs of various field, the authors analyze its main study directions and core scientific issues.
RESUMO
According to the general goal of long term development of basic science from 2021 to 2035 and the "14th Five-Year Plan" in China, starting from the reasearch characteristics and the basic situation of endemiology, this study discusses the strategic position, development law, development trend, development status and layout, development goals and realization ways of endemiology, combined with the strategic needs of the discipline, the important interdisciplinary research areas of endemiology are put forward. The purpose of this study is to promote the rapid development of basic research on endemic diseases, to provide reference for the scientific and technological layout and policy formulation of the endemiology, to provide reference for the "14th Five-Year Plan" in China, and to provide guarantee for the people in the sick area to seek health.
RESUMO
Objective:To explore the arsenic trioxide (As 2O 3)-induced apoptosis of human neuroblastoma cells (SH-SY5Y cells) and the protection mechanisms of folic acid (FA) and vitamin B 12 (VB 12). Methods:SH-SY5Y cells were cultured in vitro and divided into six groups by group design: control group (normal cultured), arsenic exposed group (10.00 μmol/L As 2O 3), FA intervention group (0.30 mmol/L FA + 10.00 μmol/L As 2O 3), VB 12 intervention group (0.06 mmol/L VB 12 + 10.00 μmol/L As 2O 3), combined intervention group (0.30 mmol/L FA + 0.06 mmol/L VB 12 + 10.00 μmol/L As 2O 3) and reagent control group (0.30 mmol/L FA + 0.06 mmol/L VB 12). Cells in each group were cultured for 24 h ( n = 3). Flow cytometry was used to determine the apoptosis rate of cells in each group. Transmission electron microscopy was used to observe the ultrastructural changes of the cells. The expression levels of mRNA and protein of apoptosis-related indicator B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X (Bax) were detected by fluorescence quantitative PCR and Western blotting. The activity of cysteinyl aspartate specific proteinase (Caspase) 3 was detected by luminescent assay. The above indicators were statistically analyzed. Results:There was statistically significant difference in the apoptosis rate among different groups ( F = 213.036, P < 0.05). The apoptosis rate in arsenic exposed group [(44.43 ± 3.54)%] was higher than that in control, FA intervention, VB 12 intervention, and combined intervention groups [(1.80 ± 0.06)%, (14.37 ± 0.13)%, (19.10 ± 1.56)%, (17.11 ± 2.34)%, P < 0.05]. Under transmission electron microscope, the apoptotic bodies, mitochondria swelling and degeneration, chromatin agglutination were observed in SH-SY5Y cells exposed to arsenic. The morphological and organelle changes of SH-SY5Y cells were significantly improved after respective and combined intervention of FA and VB 12. The expression levels of Bcl-2, Bax mRNA and protein were significantly different among different groups ( F = 5.178, 7.169, 6.142, 9.194, P < 0.05). The expression level of Bcl-2 protein in arsenic exposed group was lower than that in control group ( P < 0.05), and the expression levels of Bax mRNA and protein were higher than those in control group ( P < 0.05). The expression levels of Bcl-2 mRNA and protein in FA intervention group and combined intervention group were higher than those in arsenic exposed group ( P < 0.05), and Bcl-2 mRNA expression level in VB 12 intervention group was higher than that in arsenic exposed group ( P < 0.05). The expression levels of Bax mRNA and protein in FA intervention, VB 12 intervention and combined intervention groups were lower than those in arsenic exposed group ( P < 0.05). There were statistically significant differences in Caspase 3 activity among different groups ( F = 84.604, P < 0.05). Caspase 3 activity in arsenic exposed group was significantly higher than those in control, FA intervention, VB 12 intervention, and combined intervention groups ( P < 0.05). Conclusions:Arsenic exposure can lead to apoptosis and ultrastructural changes of SH-SY5Y cells. FA and VB 12 may effectively inhibit apoptosis through regulating Bcl-2/Bax pathway and decrease Caspase 3 activity, thus playing a protective role on nerve cells.
RESUMO
Objective:To explore the effect of fluoride exposure on the gene expression of phosphatidylinositol-3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) in rat aortic tissue, and to provide a theoretical basis for studying the mechanism of cardiovascular injury caused by endemic fluorosis.Methods:A total of 40 male Wistar rats were divided into 4 groups (10 rats in each group) via the random number table method according to body weight (80 - 100 g), namely control group (drinking distilled water), low-dose, medium-dose and high-dose groups [drinking distilled water containing 50, 100 and 150 mg/L sodium fluoride (NaF), respectively]. The rats were free to drink and eat. After feeding for 90 days, rats were sacrificed and the aortic tissue was taken. Three aortic tissue samples from the control group and the high-dose group were taken for mRNA sequencing, the differential genes were screened, and the differential genes were analyzed by GO function enrichment analysis and KEGG function enrichment analysis. At the same time, the mRNA expression levels of PI3K, Akt and eNOS in the aortic tissue of rats in each group were determined by real-time fluorescence quantitative PCR.Results:Compared with control group, there were 756 differential genes in high-dose group, including 654 up-regulated genes and 102 down-regulated genes. These differential genes were mainly related to biological processes such as muscle contraction, muscle regulation, muscle tissue development, striated muscle cell development, muscle cell differentiation, blood circulation regulation and striated muscle tissue development. They were mainly enriched in cyclic guanosine phosphate (cGMP-PKG) signaling pathway, relaxin signaling pathway and PI3K/Akt signaling pathway, etc. Compared with control group, the mRNA expression levels of PI3K and eNOS in aortic tissue of rats in low-dose, medium-dose and high-dose groups were significantly reduced ( P < 0.05); the mRNA expression level of Akt in low-dose group was significantly increased ( P < 0.05). Conclusion:Fluoride exposure has certain effects on the function and gene expression of rat aortic tissue, and PI3K/Akt/eNOS signaling pathway may play an important role in the process of fluoride induced aortic tissue injury in rats.
RESUMO
@#To explore the effect of Ginkgo biloba extract (GBE) on anticoagulation of 4 new oral anticoagulants (NOACs), dabigatran, apixaban, rivaroxaban and edoxaban in vitro, thrombin time (TT), prothrombin time (PT), activated partial thrombin time (APTT) and the activity of coagulation factor Xa (FXa) of rat plasma were measured at different concentrations of NOACs, GBE or NOACs combined with GBE, respectively. The results showed that TT, PT and APTT were prolonged with the increase of NOACs concentration in the range of 0-500 ng/mL; that except for TT of rivaroxaban, other results showed a good linear correlation with NOACs concentration (r2= 0.78-0.98); and that FXa activity decreased with increased concentration of FXa inhibitors (apixaban, rivaroxaban and edoxaban), with a good linear correlation with concentration of FXa inhibitors in the range of 0-250 ng/mL (r2= 0.85-0.94). GBE had no significant effect on TT, PT and APTT (P>0.05) in the concentration range of 0-500 μg/mL, but FXa activity had a positive linear correlation with GBE concentration (r2= 0.840 4). TT was prolonged with increasing GBE concentration when dabigatran was combined with GBE. When the above FXa inhibitors were combined with GBE, TT shortened and FXa activity increased with rising GBE concentration. There were no significant changes in PT and APTT (P>0.05) when NOACs were combined with GBE. The study results suggest that GBE may synergize with the anticoagulant activity of dabigatran and antagonize the anticoagulant activity of FXa inhibitors, possibly due to its role in increasing FXa activity.
RESUMO
Objective:To investigate the relationship between the dose of preoperative neoadjuvant radiotherapy and the pathologic complete response (pCR) rate in patients with locally advanced squamous cell esophageal cancer (ESCC).Methods:Clinical data of 116 patients with ESCC who received neoadjuvant chemoradiotherapy followed by esophagectomy in our cancer center from July 2017 to December 2019 were retrospectively analyzed. The radiation doses were divided into 2 ranges based on Grays (Gy) received: 40-45 Gy and 45 Gy or more.Results:The overall pCR rate was 38. 8%(45/116). pCR was observed in 35 out of 80(44%) patients treated with 40-45 Gy and 10 of 36(28%) patients treated with 45 Gy or more. The pCR rate did not significantly differ between two groups [(40-45 Gy) vs.( ≥ 45 Gy), P=0.105)]. Conclusions:Preoperative neoadjuvant radiotherapy with a higher dose (≥ 45 Gy) fails to increase the pCR rate in patients with locally advanced ESCC. Prospective randomized trials are required to determine the optimal dose of preoperative adjuvant radiotherapy.
RESUMO
Objective To investigate the effects of arsenic trioxide (As2O3) on oxidative stress and apoptosis of neuroblastoma cells (SH-SY5Y) and the protective effect of folic acid (FA).Methods SH-SY5Y cells were cultured in vitro,and were divided into six groups:control group,low arsenic group (2.5 μmol/L As2O3),medium arsenic group (5.0 μmol/L As2O3),high arsenic group (10.0 μmol/L As2O3),FA intervention group (10.0 μmol/L As2O3,0.3 mmol/L FA),and FA control group (0.3 mmol/L FA).Each group of cells was cultured for 24 h or 5 h.Cell chromatin agglutination was observed by fluorescence staining.The ultrastructure of cells was observed by transmission electron microscope.The changes of oxidative stress related indicators of glutathione (GSH),malondialdehyde (MDA),superoxide dismutase (SOD),and reactive oxygen species (ROS) were detected;caspase 3 activity was also detected.Results Under fluorescence microscope,as the dose of arsenic increased,the nucleus became increasingly highlighted and a small number of cells in the medium and high arsenic groups showed chromatin agglutination,and FA intervention reduced chromatin agglutination.Under transmission electron microscope,the mitochondria of low and medium arsenic groups were slightly swollen and the endoplasmic reticulum was expanded;while the mitochondria of high arsenic group were significantly swollen and the nuclear membrane was ruptured,and the apoptotic bodies were observed.Mitochondria were slightly swollen after FA intervention.There were statistically significant differences in GSH content,SOD activity,ROS level and caspase 3 activity between groups (F =14.905,6.120,12.714,36.657,P ＜ 0.05).GSH content and SOD activity in high arsenic group [0.104 ± 0.074,(12.673 ± 5.106) U/mg prot] were lower than those in control group [1.000 ± 0.000,(34.699 ±3.998) U/mg prot,P ＜ 0.05].GSH content in FA intervention group (0.411 ± 0.344) was higher than that in high arsenic group (P ＜ 0.05).The ROS level and caspase 3 activity in high arsenic group were higher than those in control group (P ＜ 0.05),and the ROS level and caspase 3 activity in FA intervention group were lower than those in high arsenic group (P ＜ 0.05).There was no significant difference in MDA content between groups (F =8.207,P ＜ 0.05).Conclusions Arsenic exposure can inhibit the activity of antioxidants,cause oxidative stress injury,and increase the activity of caspase 3,leading to cell apoptosis.FA plays an antagonistic role in arsenicinduced oxidative damage and apoptosis of nerve cells.
RESUMO
Objective To analyze the changes of endoplasmic reticulum stress (ERS) in the spleen of water-improving fluorosis rat,to explore the mechanism of fluoride-induced immune system damage,and to provide a scientific basis for prevention and control of endemic fluorosis.Methods Forty-eight male Wistar rats of SPF grade were randomly divided into control group and low,medium and high fluoride dose groups according to body mass (120-140 g),12 rats in each group.The sodium fluoride (NaF) content was 0,50,100 and 150 mg/L,respectively.The animals were allowed free access to water and food.After 12 weeks of fluoride exposure,6 rats in each group were selected to isolate the spleen;the remaining rats in each group were changed to drink distilled water containing no NaF,and the spleen was separated after 12 weeks of feeding.The levels of mRNA of glucoseregulated protein (GRP78),spliced X-box binding protein 1 (XBP1-s),activating transcription factor 4 (ATF4),homologous protein (CHOP) and cysteine containing aspartate specific protease 12 (Caspase-12) in spleen were determined by quantitative real-time PCR (qRT-PCR).Results Before the water-improving,the expressions of GRP78 (1.00 ± 0.09,1.69 ± 0.35,1.39 ± 0.29,1.19 ± 0.19),XBP1-s (1.00 ± 0.12,1.40 ± 0.23,1.24 ± 0.26,1.38 ± 0.11),ATF4 (1.00 ± 0.17,1.86 ± 0.56,2.33 ± 0.55,1.95 ± 0.74),CHOP (1.00 ± 0.53,2.84 ± 0.68,3.06 ± 1.29,2.50 ± 0.35) and Caspase-12(1.00 ± 0.12,1.90 ± 0.29,1.56 ± 0.35,1.76 ± 0.23) mRNA in the control group and low,medium and high fluoride dose groups were statistically significant (F =8.45,5.38,6.38,8.21,11.31,P ＜ 0.05).Except for the GRP78 in high fluoride dose group,the above indicators in fluoride groups were higher than the control group (P ＜ 0.05).After the water-improving,the expressions of GRP78 (1.00 ± 0.36,0.75 ± 0.13,0.98 ± 0.41,0.47 ± 0.19),XBP1-s (1.00 ± 0.25,0.70 ± 0.06,0.74 ± 0.17,0.65 ± 0.21),ATF4 (1.00 ± 0.51,0.66 ± 0.09,0.91 ± 0.34,0.81 ± 0.29),CHOP (1.00 ± 0.36,0.92 ± 0.12,0.84 ± 0.16,0.67 ± 0.20) and Caspase-12 (1.00 ± 0.45,0.65 ± 0.11,0.65 ± 0.25,0.51 ± 0.27) mRNA in the control group and low,medium and high fluoride dose groups were not statistically significant (P ＞ 0.05).Before and after the water-improving,the expressions of XBP1-s,ATF4,CHOP and Caspase-12 mRNA were statistically significant in fluoride groups (P ＜ 0.05),and the GRP78 only had a statistically significant difference in the low fluoride dose group (P ＜ 0.05).Conclusions Fluoride exposure causes ERS response in rat spleen,up-regulation of ERS-related gene expression,which is decreased after water-improving,and the ERS response is weakened.The water-improving may contribute to the recovery of fluoride-induced immune function damage.
RESUMO
Objective To observe the effects of long-term low dose arsenic exposure through drinking water on learning ability of different generations of C3H and Balb/c mice.Methods Mice (C3H and Balb/c) were exposed to arsenic at 0 mg/L (control) and 85 mg/L (20 female mice and 10 male mice per group).The control group and F1,F2,F3 and F4 mice were selected and divided into 5 experimental groups,8 mice in each group.Their offsprings were detected by the Morris water maze test (the average escape latency of 1 to 5 days) and spatial probe test (the times of through target area on the sixth day).Statistical analysis was performed with SPSS 18.0 software.Results The average escape latencies of 1 to 5 days in C3H control group were (48.09 ± 2.63),(46.09 ± 3.27),(42.72 ± 3.29),(39.31 ± 2.69) and (36.75 ± 3.92) s,F1 were (49.59 ± 3.29),(47.34 ± 3.01),(44.28 ± 6.58),(44.50 ±1.67) and (42.16 ± 2.27) s,F2 were (51.41 ± 0.78),(48.88 ± 1.45),(45.54 ± 1.46),(43.94 ± 1.69) and (42.22 ± 3.27) s,F3 were (50.91 ± 4.20),(49.78 ± 5.18),(48.03 3.45),(46.16 ± 4.42) and (44.06 ± 1.04) s,F4 were (52.66 ± 4.60),(52.38 ± 5.78),(49.06 ± 1.22),(47.69 ± 2.34) and (46.47 ± 1.56) s.The average escape latencies of Balb/c control group were (50.91 ± 2.84),(47.03 ± 4.22),(45.56 ± 4.53),(39.72 ± 5.90) and (36.22 ± 4.85) s,F1 were (50.47 ±3.20),(48.25 ± 6.53),(47.13 ± 1.25),(43.72 ± 4.27) and (40.66 ± 4.52) s,F2 were (51.31 ± 4.73),(48.88 ± 1.53),(46.56 ± 1.43),(44.25 ± 1.16) and (41.20 ± 3.79) s,F3 were (51.72 ± 3.54),(50.78 ± 4.45),(45.03 ± 3.56),(41.19 ±5.63) and (42.81 ± 6.29) s,F4 were (53.34 ± 4.60),(52.34 ± 2.77),(48.72 ± 5.92),(46.97 ± 7.38) and (44.94 ± 1.75) s.On the fourth and fifth days of F1,F2,F3 and F4 generations of C3H,the escape latencies between generations were significantly different (all P ＜ 0.05).The times of through target area in the sixth day of the C3H control group and F1,F2,F3 and F4 mice were 2.25,1.75,1.63,1.50 and 1.38,Balb/c were 2.13,1.75,1.63,1.38 and 1.13.Conclusion Arsenic accumulation due to serial passage of C3H and Balb/c through long-term low doses arsenic exposure through drinking water has resulted in decreased learning and memory ability.
RESUMO
Objective To observe the changes of the totle nitric oxide synthase (NOS) activity in brain tissue,the metabolism of arsenic speciations in urine and the totle contents in blood,brain after rats drinking water containing different doses of arsenic.Methods Forty SD rats were divided into 4 groups according to random number table,10 rats in each group:control group,5 mg/L NaAsO2 group,10 mg/L NaAsO2 group and 50 mg/L NaAsO2 group.The animals were allowed free access to water and food.Body mass was weighted once a week.Expose to arsenic was continued for three months,then the animals were put to death and their blood,urine and brain tissues were collected.Determination of four kinds of speciations of arsenic (3 valence inorganic arsenic,iAs3+;5 valence inorganic arsenic,iAs5+;monomethylated arsenic,MMA;dimethylated arsenic,DMA) in urine was carried out by high performance liquid chromatography-hydride atomic fluorescence spectrometry.Total arsenic concentration in blood and brain tissue was detected by Atomic Fluorescence Spectrometry.The activity of total NOS in blood and brain tissue was detected using the spectrophotometer method.Results ①Weight:at the 5th-12th week after arsenic exposure,compared with the weight of control group [(420.93 ± 21.13),(441.52 ± 28.85),(462.45 ± 30.57),(470.16 ± 31.17),(484.92 ± 32.93),(483.79 ± 29.63),(482.02 ± 29.14),(483.89 ± 29.31) g],weight of rats in 50 mg/L NaAsO2 group [(391.66 ± 32.88),(410.17 ± 33.47),(426.96 ± 33.49),(427.15 ± 32.20),(441.78 ± 33.69),(438.27 ± 33.05),(440.98 ± 33.33),(441.46 ± 32.45) g] was significantly lighter (all P ＜ 0.05).② Urine arsenic:the medians of iAs3+ content (0.00,57.30,236.33,857.80 μg/L) were compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (x2 =31.982,P ＜ 0.01);the medians of iAs5+ content (0.00,0.00,80.75,162.90 μg/L) were compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (x2 =24.206,P ＜ 0.01);the medians of DMA content (12.83,1 711.13,l0 386.20,37 038.90 μg/L) were compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (x2 =34.338,P ＜ 0.01).③Blood arsenic:total arsenic content in serum of rats [(5.04 ± 1.57),(25.40 ± 7.33),(32.28 ± 7.75),(56.11 ± 19.87) mg/L] was compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (F =27.78,P ＜ 0.05).④Brain arsenic:total arsenic content in brain tissue of 5,10 and 50 mg/L NaAsO2 groups [(0.57 ± 0.20),(1.56 ± 0.52),(3.63 ± 0.48) μg/g] was respectively compared with that of control group [(0.11 ± 0.06) μg/g],the differences were statistically significant (all P ＜ 0.05).⑤NOS activity:compared with control group [(27.69 ± 5.56) kU/L],total NOS activity [(33.63 ± 2.26),(34.19 ± 2.55) kU/L] in serum of rats in 10 mg/L NaAsO2 group and 50 mg/L NaAsO2 group increased significantly (all P ＜ 0.05);compared with control group [(1.79 ± 0.79) U/(mg·prot)],total NOS activity [(2.63 ± 0.60)U/(mg ·prot)] in brain tissue of 50 mg/L NaAsO2 group increased significantly (P ＜ 0.05).Conclusions A high dose of arsenic exposure can increase totle contents of arsenic in blood,brain and the activity of total NOS in rat brain tissue.