Sirtuin-3 activates the mitochondrial unfolded protein response and reduces cerebral ischemia/reperfusion injury.

Sirtuin-3 (Sirt3) deacetylates several mitochondrial proteins implicated into cerebral ischemia/reperfusion (I/R) injury. The mitochondrial unfolded protein response (UPRmt) favors mitochondrial proteostasis during various stressors. Here, we used Sirt3 transgenic mice and a transient middle cerebral artery occlusion model to evaluate the molecular basis of Sirt3 on the UPRmt during brain post-ischemic dysfunction. The present study illustrated that Sirt3 abundance was suppressed in the brain after brain ischemic abnormalities. Overexpression of Sirt3 in vivo suppressed the infarction size and attenuated neuroinflammation after brain I/R injury. Sirt3 overexpression restored neural viability by reducing mitochondrial ROS synthesis, maintaining the mitochondrial potential and improving mitochondrial adenosine triphosphate synthesis. Sirt3 overexpression protected neuronal mitochondria against brain post-ischemic malfunction via eliciting the UPRmt by the forkhead box O3 (Foxo3)/sphingosine kinase 1 (Sphk1) pathway. Inhibiting either the UPRmt or the Foxo3/Sphk1 pathway relieved the favorable influence of Sirt3 on neural function and mitochondrial behavior. In contrast, Sphk1 overexpression was sufficient to reduce the infarction size, attenuate neuroinflammation, sustain neuronal viability and prevent mitochondrial abnormalities during brain post-ischemia dysfunction. Thus, the UPRmt protects neural viability and mitochondrial homeostasis, and the Sirt3/Foxo3/Sphk1 pathway is a promosing therapeutic candidate for ischemic stroke.

Effects of nitrogen and phosphorus addition on growth and leaf nitrogen metabolism of alfalfa in alkaline soil in Yinchuan Plain of Hetao Basin.

Alkaline soil is widely distributed in China. Its rational utilization is an effective measure to solve land shortage and improve the environment. Alfalfa is characterized by strong salt and alkali tolerance and high yield and protein content. Nitrogen (N) and phosphorus (P) are the main nutrients for plant growth, and N metabolism is one of the primary forms of plant metabolism, which plays a vital role in quality and yield formation. The exploration of the effect of N and P on N metabolism and alfalfa growth will provide a theoretical basis for scientific fertilization for alfalfa in the alkaline soil of the Yinchuan Plain of the Hetao Basin. Therefore, a 2-year experiment of N and P addition was conducted. Six treatments were set up with a randomized block design, including without N (WN), medium N (MN), high N (HN), without P (WP), medium P (MP), and high P (HP). It was found that the MN and MP treatments increased plant height, stem diameter, stem/leaf, dry/fresh, and dry matter of alfalfa. The HN and HP treatments inhibited alfalfa biomass formation. The MN and MP treatments increased key products and enzymes of leaf N metabolism of alfalfa and promoted activities of leaf nitrate reductase (NR), glutamine synthase (GS), glutamate synthase (GOGAT), glutamic-oxalacetic transaminase (GOT), and glutamic-pyruvate transaminase (GPT), and inhibited activities of leaf protease of alfalfa. The MN and MP treatments increased contents of leaf N, P, ammonium nitrogen (NH4 +-N), nitrate nitrogen (NO3 --N), total chlorophyll, and protein and reduced leaf chlorophyll a/b and amino acid, results after HN and HP treatments were opposite. The correlation among leaf P, N, NO3 --N, amino acid, and protein reached significant levels (P < 0.01). It is suggested that MN and MP treatments can improve the yield and quality of alfalfa by increasing key products and enzymes of N metabolism and can be adopted to promote alfalfa production in the alkaline soil of the Yinchuan Plain of the Hetao Basin.

Application of flipped classroom based on rain classroom in standardized residency training of orthopedics / 中华医学教育探索杂志

Objective:To evaluate the application of flipped classroom based on rain classroom in standardized residency training of orthopedics.Methods:Sixty-two orthopedics residents were randomly divided into flipped classroom teaching group and traditional teaching group, with 31 residents in each group. The flipped classroom teaching group the flipped classroom teaching mode based on rain classroom, including three aspects: learning in advance before rain classroom, personalized discussing cases in class and teaching after class. The theoretical knowledge, clinical skills and evaluation of teaching activities were compared between the two groups. SPSS 19.0 was used for rank sum test and chi-square test.Results:All the residents completed the evaluation of theoretical knowledge, clinical skills and effect. The results showed that the scores of theoretical knowledge and clinical skills in the flipped classroom teaching group were (88.7±10.3) points and (26.8±2.2) points, which were significantly higher than those of the traditional teaching group (79.2±18.6) points and (20.4±2.9) points, with statistical significance ( P<0.05). The evaluation of teaching activities, including participation, satisfaction, enthusiasm and learning effect, was significantly better than that of the traditional teaching group ( P<0.05). Conclusion:In the orthopedics standardized residency training and teaching activities, the application of flipped classroom teaching mode based on rain classroom is conducive to improving students' learning performance, cultivate their autonomous learning ability, and improve their learning satisfaction and enthusiasm.

Large-scale single-cell analysis reveals critical immune characteristics of COVID-19 patients

Dysfunctional immune response in the COVID-19 patients is a recurrent theme impacting symptoms and mortality, yet the detailed understanding of pertinent immune cells is not complete. We applied single-cell RNA sequencing to 284 samples from 205 COVID-19 patients and controls to create a comprehensive immune landscape. Lymphopenia and active T and B cell responses were found to coexist and associated with age, sex and their interactions with COVID-19. Diverse epithelial and immune cell types were observed to be virus-positive and showed dramatic transcriptomic changes. Elevation of ANXA1 and S100A9 in virus-positive squamous epithelial cells may enable the initiation of neutrophil and macrophage responses via the ANXA1-FPR1 and S100A8/9-TLR4 axes. Systemic upregulation of S100A8/A9, mainly by megakaryocytes and monocytes in the peripheral blood, may contribute to the cytokine storms frequently observed in severe patients. Our data provide a rich resource for understanding the pathogenesis and designing effective therapeutic strategies for COVID-19. HIGHLIGHTSO_LILarge-scale scRNA-seq analysis depicts the immune landscape of COVID-19 C_LIO_LILymphopenia and active T and B cell responses coexist and are shaped by age and sex C_LIO_LISARS-CoV-2 infects diverse epithelial and immune cells, inducing distinct responses C_LIO_LICytokine storms with systemic S100A8/A9 are associated with COVID-19 severity C_LI

An exploration of public health practical skill training among undergraduates majoring in preventive medicine / 中华医学教育探索杂志

In order to enhance the level of public health practical skills among undergraduates majoring in preventive medicine and improve the professional skills of disease prevention and control staff in case of public health emergencies,Nanjing Medical University School of Public Health performed an individual protection training for senior undergraduates majoring in preventive medicine in 2017.After related experience was summarized and students' feedback was collected,comprehensive training of public health practical skills was pedormed for senior undergraduates majoring in preventive medicine in 2018,with the inclusion of virtual experiments for public health.The results showed that the students were interested in practical skill training,mastered the contents of the training,and took pride in their major.This training has an excellent teaching effect and can enhance the ability to deal with public health emergencies among students majoring preventive medicine.

Analysis of reciprocal sharing of large medical devices at the medical alliance headed by the Third People′s Hospital of Wuxi / 中华医院管理杂志

Reciprocal sharing of medical devices plays a breakthrough point for strengthening medical alliances, while promoting efficiency building is the core work of medical devices sharing as well. Taking this medical alliance as an example, this paper discussed the effective strategies of large medical devices sharing within the medical alliance. The measures taken include basic information research and expert interview, high-level planning, and information platform, as well as incentive protection, effectiveness evaluation and atmosphere construction. These efforts can enhance the service support, satisfaction, inspection income, full usage, work ability, new function extension, and equipment management. Furthermore, it can promote the service ability, telemedicine and hierarchical medical of the medical alliance.

Effective gene editing by high-fidelity base editor 2 in mouse zygotes

Targeted point mutagenesis through homologous recombination has been widely used in genetic studies and holds considerable promise for repairing disease-causing mutations in patients. However, problems such as mosaicism and low mutagenesis efficiency continue to pose challenges to clinical application of such approaches. Recently, a base editor (BE) system built on cytidine (C) deaminase and CRISPR/Cas9 technology was developed as an alternative method for targeted point mutagenesis in plant, yeast, and human cells. Base editors convert C in the deamination window to thymidine (T) efficiently, however, it remains unclear whether targeted base editing in mouse embryos is feasible. In this report, we generated a modified high-fidelity version of base editor 2 (HF2-BE2), and investigated its base editing efficacy in mouse embryos. We found that HF2-BE2 could convert C to T efficiently, with up to 100% biallelic mutation efficiency in mouse embryos. Unlike BE3, HF2-BE2 could convert C to T on both the target and non-target strand, expanding the editing scope of base editors. Surprisingly, we found HF2-BE2 could also deaminate C that was proximal to the gRNA-binding region. Taken together, our work demonstrates the feasibility of generating point mutations in mouse by base editing, and underscores the need to carefully optimize base editing systems in order to eliminate proximal-site deamination.

Correction of β-thalassemia mutant by base editor in human embryos

β-Thalassemia is a global health issue, caused by mutations in the HBB gene. Among these mutations, HBB -28 (A>G) mutations is one of the three most common mutations in China and Southeast Asia patients with β-thalassemia. Correcting this mutation in human embryos may prevent the disease being passed onto future generations and cure anemia. Here we report the first study using base editor (BE) system to correct disease mutant in human embryos. Firstly, we produced a 293T cell line with an exogenous HBB -28 (A>G) mutant fragment for gRNAs and targeting efficiency evaluation. Then we collected primary skin fibroblast cells from a β-thalassemia patient with HBB -28 (A>G) homozygous mutation. Data showed that base editor could precisely correct HBB -28 (A>G) mutation in the patient's primary cells. To model homozygous mutation disease embryos, we constructed nuclear transfer embryos by fusing the lymphocyte or skin fibroblast cells with enucleated in vitro matured (IVM) oocytes. Notably, the gene correction efficiency was over 23.0% in these embryos by base editor. Although these embryos were still mosaic, the percentage of repaired blastomeres was over 20.0%. In addition, we found that base editor variants, with narrowed deamination window, could promote G-to-A conversion at HBB -28 site precisely in human embryos. Collectively, this study demonstrated the feasibility of curing genetic disease in human somatic cells and embryos by base editor system.

CRISPR/Cas9-mediated gene editing in human tripronuclear zygotes

Genome editing tools such as the clustered regularly interspaced short palindromic repeat (CRISPR)-associated system (Cas) have been widely used to modify genes in model systems including animal zygotes and human cells, and hold tremendous promise for both basic research and clinical applications. To date, a serious knowledge gap remains in our understanding of DNA repair mechanisms in human early embryos, and in the efficiency and potential off-target effects of using technologies such as CRISPR/Cas9 in human pre-implantation embryos. In this report, we used tripronuclear (3PN) zygotes to further investigate CRISPR/Cas9-mediated gene editing in human cells. We found that CRISPR/Cas9 could effectively cleave the endogenous β-globin gene (HBB). However, the efficiency of homologous recombination directed repair (HDR) of HBB was low and the edited embryos were mosaic. Off-target cleavage was also apparent in these 3PN zygotes as revealed by the T7E1 assay and whole-exome sequencing. Furthermore, the endogenous delta-globin gene (HBD), which is homologous to HBB, competed with exogenous donor oligos to act as the repair template, leading to untoward mutations. Our data also indicated that repair of the HBB locus in these embryos occurred preferentially through the non-crossover HDR pathway. Taken together, our work highlights the pressing need to further improve the fidelity and specificity of the CRISPR/Cas9 platform, a prerequisite for any clinical applications of CRSIPR/Cas9-mediated editing.

Research of Narcotrend monitor for the prevention of awareness during general anesthesia / 中国医师进修杂志

ObjectiveTo study the clinical efficacy and safety of Narcotrend (NT) monitor for the prevention of awareness during general anesthesia.MethodsFour hundred and thirty-two patients with elective extubation and general anesthesia (ASA Ⅰ-Ⅱ) were divided into observation group and control group with 216 cases each by random digits table.All patients were treated with total intravenous anesthesia.The patients were given anesthetics by NT monitor in observation group and detemined by the clinical experience of anesthesiologists in control group.The mean arterial pressure (MAP),heart rate (HR),respiratory rate(RR),pulse oxygen saturation(SpO2),NT stages (NTS),NT index (NTI),total sedatives,awaking time,extubation time,Ramsay score was recorded.All patients in the postoperative on the first day and the fourth day were followed-up two times to understand the perception and memory in patients undergoing the situation.ResultsThere was no know in operation in observation group,there was 1 case with suspectedknow and 1 case with definite know in control group.Compared with control group,the awaking time and extubation time was decreased in observation group [ ( 6.0 ± 2.8 ) min vs.( 10.0 ± 4.9 ) min,( 12.0 ± 5.5 ) min vs.( 19.0 ± 6.9) min] (P ＜ 0.05 ); MAP and HR was even more stable.In addition to midasolam,the remaining amount of the drug was less (P ＜ 0.05 ).Ramsay score at awaking,extubation and out of the operating room in observation group was lower than that in control group (P ＜ 0.05).ConclusionNT monitor for total intravenous anesthesia increases the safety of general anesthesia,and it can be reduced to some extent,intraoperative awareness.

On skull recognition of quadratic rational Bezier curve fitting / 生物医学工程学杂志

Skull recognition is a new method of biometrics recognition. A skull recognition algorithm is presented in this paper by Quadratic rational Bezier curve fitting which accurately describes the feature of skull edge; the experiment results based on skull x-ray image show the correctness of this method.

Experimental study on the anticancer effect of Curcumine on mice of S180 in vivo / 西安交通大学学报(医学版)

Objective To study Curcumine's growth-inhibitory effects and morphological changes on sarcoma grafts of S180 mice,with further inquiry into the possible mechanism.Methods A total of 30 cases of S180 mice were assigned randomly into 3 groups: saline group(blank control),CTX group(positive controlled) and Curcumine group.① The anti-tumor effect on internal organ of mice was observed to study the tumor inhibition rate in different groups.② Influence of curcumine on mice's immune system was studied by comparing the index of thymus and spleen.③ The growth and patho-morphologic changes of tumor cells were observed.④To calculate the index of apoptosis cells and observe the morphological changes of all groups' apoptosis cells under electroscope.Results ① The inhibitory rate was 68.32% in the curcumine group,70.43% in the positive controlled group.Compared to blank control group, these two groups had significantly elevated tumor inhibition rate(P0.05);however,positive thymus index in control group had significant decrease compared with that in the other two groups(P0.05).③ Under electroscope,curcumine group and positive control group had significant decrease in growth of tumor,degree of tumor infiltration,number of nucleus fission,and blood vessel number compared to those in negative control group(P