Development of public health personnel team in Center for Disease Control and Prevention in context of COVID-19 / 上海预防医学

ObjectiveIn the context of COVID-19 prevention and control， to summarize the current situation of the public health personnel team development against the pandemic at a county-level center for disease control and prevention （CDC） in Shanghai’s extra-large urban area， to analyze and summarize the current situation and existing problems of the public health personnel team of the district and county-level CDCs， and to propose measures to strengthen and improve the development. MethodsTaking the Shanghai Pudong New Area Center for Disease Control and Prevention， which serves a population of 5.68 millions， as an example， through information access， individual interviews， questionnaires， holding symposiums， etc.， combined with the deployment of personnel in the handling of the COVID-19， we described the Pudong New Area CDC’s talent team characteristics， personnel recruitment and loss， and investigated the factors affecting the construction of talent team. ResultsFrom 2014 to 2020， Pudong CDC recruited 115 people， and 65.71% of them chose to work there. 68 people resigned， with an average of 6.8 people leaving every year， with a fluctuating upward trend in resignation rate （χ2=0.158，P<0.05）. Since we entered the phase of regular COVID-19 prevention and control in 2020， the staff have been overloaded with work， based on the number of hours spent dealing with the pandemic on the spot and the number of people on the job. In 2017 to 2019， the salary of staff was basically maintained at the level of 2016 （average annual growth of about 2.5%）； it lacked targeted talent recruitment （one-time resettlement fee， etc.） and talent retention incentives （monthly housing subsidy for new employees， etc.）. According to the questionnaire’s results， 79.23% of the respondents believed that the talent incentive mechanism needs to be improved， 73.43% believed that a good environment for talent growth needs to be created， and 50.24% thought that the employment mechanism needs to be reformed. It is difficult to meet the needs of pandemic prevention and control under the new situation with the current number of public health personnel， the recruitment of talents is insufficient， the turnover is too high， and there is a gap between the ability of some public health personnel and what is required of them under the new situation and new tasks. ConclusionThe quantity and quality of public health personnel for disease control in Shanghai can hardly meet the needs of pandemic prevention and control under the new situation. The pertinence and systematization of public health talent training urgently need to be strengthened， and the incentive mechanism needs to be improved.

A Novel Autophagy-Related Marker for Improved Differential Diagnosis of Rheumatoid Arthritis and Osteoarthritis.

Rheumatoid arthritis (RA) and osteoarthritis (OA) are two most common rheumatic diseases in the world. Although there are standard methods for the diagnosis of both RA and OA, the differentials in some cases are poor. With deepening research, the role of autophagy in maintaining cell homeostasis and thus enabling cells adapt to external environments has become increasingly prominent. Both RA and OA, two diseases with inherent differences in pathogenesis, gradually show differences in autophagy levels. Our study therefore aims to further understand differences in pathogenesis of RA and OA through in-depth studies of autophagy in RA and OA. We also define appropriate autophagy-related markers as recognition indicators. Differences in autophagy levels between RA and OA were found based on analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and single-sample gene set enrichment (ssGSEA). These differences were mainly caused by 134 differentially expressed genes (DEGs). In two autophagy-related genes, CXCR4 and SERPINA1, there existed significant statistical difference between RA and OA. An autophagy related index (ARI) was thus successfully constructed based on CXCR4 and SERPINA by binary logistic regression of the generalized linear regression (GLR) algorithm. Pearson analysis indicated that the expression of CXCR4, SERPINA1, and ARI were closely correlated with autophagy scores and immune infiltration. Moreover, ARI showed high disease identification through receiver operating characteristic (ROC) analysis (AUCtesting cohort = 0.956, AUCtraining cohort = 0.867). These results were then verified in GSE12021 independent cohort. In conclusion, ARI associated with autophagy and immune infiltration was successfully constructed for accurately identifying OA and RA. The index, thus, has great potential in clinical applications.

Hollow ferric-tannic acid nanocapsules with sustained O2 and ROS induction for synergistic tumor therapy.

Nanoparticles presenting promoted catalytic activity, oxygen induction and loading capability are in high demand for effective synergistic tumor therapy. Herein, ferric-tannic acid complex nanocapsules with fine hollow microstructure (HFe-TA) are synthesized and loaded with a photosensitizer (indocyanine green, ICG) for synergistic tumor therapy. In acidic environment, ICG@HFe-TA decomposes and releases Fe3+ ions, TA and ICG molecules. Fe3+, with low catalytic activity, is effectively converted into highly catalytic Fe2+ by the reductant TA, enabling promoted efficacy of ˙OH induction. More importantly, the ROS (1O2) induction by ICG is significantly enhanced under 808 nm laser irradiation due to the O2 byproduct of Fe3+/Fe2+ conversion. In consequence, the ICG@HFe-TA nanoparticles exhibit considerable in vitro and in vivo tumor inhibition owing to the combined effect of ˙OH and 1O2 induced intracellularly. This study has therefore demonstrated a potential platform enabling combined photodynamic and chemodynamic therapy with high efficacy.

Toxicity testing of four silver nanoparticle-coated dental castings in 3-D LO2 cell cultures / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical applications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.

Induction ways of bone marrow mesenchymal stem cells differentiating into nerve cells★ / 中国组织工程研究

BACKGROUND:Currently, bone marrow mesenchymal stem cel s can differentiate into nerve cel s via many approaches. Different methods for inducing bone marrow mesenchymal stem cel s differentiating into nerve cel s have different ratios. OBJECTIVE:To investigate the difference between chemical method and co-culture method to induce the differentiation of rat bone marrow mesenchymal stem cel s into nerve cel s. METHODS:Rat bone marrow mesenchymal stem cel s were isolated and purified using whole bone marrow culture method, and then randomly divided into two groups:chemical group,β-mercaptoethanol was added;co-culture group, co-cultured in a Transwel chamber. RESULTS AND CONCLUSION:Visible protrusions from induced cel s showed radiation growth at 1 week of induced culture, and neuron-specific enolase staining was positive at 2 weeks of culture. Star-like structure of nerve cel s was visible in the co-culture group within 4-5 days of culture, and then more protrusions formed. Meanwhile, the positive rate of neuron-specific enolase was (70.82±2.46)%. After 6-7 days of culture, neuron-like cel s formed and were interconnected in the chemical group;while, the positive rate of neuron-specific enolase was (52.37±1.83)%. These findings suggest that cel microenvironment plays a leading role in the differentiation of bone marrow mesenchymal stem cel s into nerve cel s, and chemical induction method is inferior to the co-culture method.

The effects of nucleoside analogues on hepatitis B virus in hepatic lymph nodes of hepatitis B virus-associated liver transplantation recipients / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of nucleoside analogues on hepatitis B virus (HBV) in hepatic lymph nodes of hepatitis B related liver transplantation recipients who were hepatitis B surface antigen (HBsAg) positive but negative for serum HBV DNA.</p><p><b>METHODS</b>From June 2010 to March 2011, thirty-six cases of hepatitis B related liver transplantation recipients [32 males, 4 females, average age (54 ± 7) years] were divided into drug treatment group and non-drug treatment group according to the utility of nucleoside analogues. Drug treatment group was divided into two subgroups: drug treatment > 3 months group and drug treatment ≤ 3 months group. The hepatic lymph nodes in the hepatoduodenal ligament were taken during the operation of liver transplant. Using nested or semi-nested PCR, HBV DNA and the replicative form HBV cccDNA in hepatic lymph nodes were detected. Data were analyzed by Fisher's exact test.</p><p><b>RESULTS</b>The positive rate of HBV DNA: the difference was not statistically significant between drug treatment group (72.7%, 16/22) and non-drug treatment group (14/14) (P = 0.062), the difference was not statistically significant between drug treatment > 3 months group (10/14) and drug treatment ≤ 3 months group (6/8) in the subgroups of drug treatment group (P = 1.000). The positive rate of HBV cccDNA: drug treatment group (22.7%, 5/22) was significantly lower than the non-drug treatment (12/14) (P = 0.000), drug treatment > 3 months group (1/14) was significantly lower than drug treatment ≤ 3 months group (4/8) in the subgroups of drug treatment group (P = 0.039).</p><p><b>CONCLUSIONS</b>Hepatic lymph nodes maybe one of the extrahepatic HBV reservoirs. Treating with nucleoside analogues more than 3 months can significantly decrease the replication of HBV in hepatic lymph nodes of HBV associated liver transplantation recipients.</p>

Differentiation of umbilical cord blood mesenchymal stem cells into osteoblasts in vitro / 中国组织工程研究

BACKGROUND: Umbilical cord blood mesenchymal stem cells (UCB-MSCs) can differentiate into various types of cells under certain condisions, and easily proliferate in vitro. However, UCB-MSCs have long establishment time and low frequency.OBJECTIVE: To in vitro isolate and culture UCB-MSCs, and induce its differentiation into osteoblasts.DESIGN, TIM E AND SETTING: The in vitro cytological study was performed at the Laboratory of the Medical College of Qingdao University from June 2008 to January 2009.MATERIALS: UCB was obtained from term normal delivery women at the Department of Gynaecology and Obstetrics, Qingdao Municipal Hospital.METHODS: Human UCB-MSCs were isolated and cultured in vitro by Percoll density gradient. When reached 90% confluency,UCB-MSCs were digested by trypsin for subculture. At the third passage, UCB-MSCs at 1×106 were incubated. When reached 50% 60% cenfluency, UCB-MSCs were treated with DMEM supplemented with 0.1 μmol/L dexamathasone, 10 mmol/Lβ-sodium glycerophosphate and 50 μmol/L vitamin C. UCB-MSCs in the control group were incubated in low glucose DMEM.MAIN OUTCOME MEASURES: Growth and proliferation of MSCs were observed under the inverted microscope. Cell surface marker expression and cell growth curve were measured by flow cytometry. Cell ultrastructure was observed under the transmission electron microscope. Differentiation of UCB-MSCs into osteoblasts was determined by Won Kossa staining and alkaline phosphatase staining.RESULTS: Primary cultured UCB-MSCs had similar morphology to bone marrow mesenchymal stem cells. After passage, cell morphology was even, presenting spindle shape. UCB-MSCs at passage 3 highly expressed CD29, CD44, CD13, but did not express CD34. Growth latency was 2-3 days. Cells entered logarithm proliferation phase at days 3-4, and platform phase 1 month later. Nuclei presented round or irregular, with clear nuclear membrane, 1-2 nucleoli, rough chromatin, abundant organelles and microvilli. UCB-MSCs at passage 3 were gradually confluent following 3 days of osteogenic induction, with the presence of pavement-stone shape. 14 days later, calcified nodules by Von Kossa staining, and cells were positive for alkaline phosphatase staining. In the control group, no calcified nodules were found, and cells were negative for alkaline phosphatase staining.CONCLUSION: UCB-MSCs can be successfully isolated by Percoil density gradient, and induced to differentiate into osteoblasts in vitro.