Objective:To analyze the epidemiological and clinical characteristics of imported COVID-19 cases after SARS-CoV-2 vaccination and to provide evidence for the prevention and control of COVID-19.Methods:The imported COVID-19 cases in Chengdu as of April 15, 2021 were divided into the vaccinated group and unvaccinated group according to the history of SARS-CoV-2 vaccination. The epidemiological and clinical data of the cases were collected retrospectively, and the differences in epidemiological and clinical characteristics of the two groups were compared. Laboratory tests consisted of nucleic acid test, clinical index test, serum antibody test and lymphocyte test. Software WPS2019 was used for data management and software R 4.0.3 was used for statistical analysis.Results:A total of 75 COVID-19 cases were included in the analysis, in which 20 had received SARS-CoV-2 vaccination and only 4 with clinical symptoms, 55 patients did not receive SARS-CoV-2 vaccination, and 16 had clinical symptoms. In vaccinated group, the first injection time of vaccination ranged from July to November 2020, and 10 cases received two doses of vaccine simultaneously and 10 cases received two doses of vaccine at intervals of 14-57 days. The intervals between the completion of vaccination and the onset ranged from 87 days to 224 days. The differences in classification and clinical type between the two groups were significant. Significant differences were observed in case classification and clinical type between vaccinated group and unvaccinated group ( P<0.05). The vaccinated group had a relatively high proportion of asymptomatic infections (40.00%, 8/20), while mild infections were mainly observed in the unvaccinated group(76.36%,42/55). The differences in Ct values (ORF1ab gene and N gene) at the diagnosis were not significant between vaccinated group and unvaccinated group ( P>0.05), similar results were also observed in lymphocyte subtypes, procalcitonin and C-reactive protein level comparisons. Serum amyloid A level was higher in unvaccinated group than in vaccinated group ( P<0.05). However, the SARS-CoV-2 related serum antibody of IgM, IgG and total antibody levels were significantly higher in vaccinated group ( P<0.05). Conclusions:Risk of infection still exists with SARS-CoV-2 after vaccination, which can facilitate the production of specific serum antibody of IgM and IgG when people are exposed to the virus. It has a certain protective effect on SARS-CoV-2 infected persons. Vaccination can reduce the clinical symptoms and mitigate disease severity.

Objective: To analyze the developmental relationship between mesenchymal stem/progenitor cells (MSPCs) and hematopoietic cells during human embryogenesis. Methods: Aborted embryos at different developmental stages were used in this study after medical abortion. Embryonic blood tissues were isolated and digested into single cells. These single cells were plated in semisolid medium in favor of the differentiation of colony-forming cell with high proliferative potential (HPP-CFC) and incubated for 10 to 14 d. Individual colonies with diameter more than 0.5 mm were picked and replated in liquid medium. Fibroblastic adherent cells appeared in the replated colonies were cultured for cell proliferation and cytokins expressed on cell surface were identified to analyze whether they had the characteristics of MSPCs. Results: This study summarized the dynamic development of HPP-CFCs and other hematopoietic progenitor cells in different tissues including aorta-gonad-mesonephros (AGM) region, yolk sac and embryonic liver. From the 28-somite stage, a proportion of HPP-CFCs in AGM region could give rise to adherent fibroblastic cells in addition to hematopoietic cells. The adherent cells harbored the differentiation potential of MSPCs and could inhibit the proliferation of T cells in lymphocyte transformation test. Conclusions This study suggests some prehematopoietic precursors in AGM region can give rise to both hematopoietic progenitors and MSPCs during human embryogenesis.

OBJECTIVETo study the effect of Platycarya strobilacea Sieb. et Zucc (PSZ) extract on methuosis of human nasopharyngeal carcinoma CNE1 and CNE2 cells and explore the underlying mechanism.

METHODSCNE1 and CNE2 cells were treated with 1 mg/mL PSZ extract and the expressions of Rac1 mRNA and Rac1 protein were detected using RT-qPCR and Western blotting, respectively. Results CNE1 and CNE2 cells showed obvious morphological changes typical of methuosis following treatment with PSZ extract characterized by cell merging, accumulation of large cytoplasmic vacuoles, and membrane rupture without obvious changes in the nuclei. PSZ treatment resulted in up-regulated Rac1 mRNA and Rac1 protein expressions in the cells. Application of EHT 1864 obviously blocked the effect of PSZ extract in inducing methuosis in CNE1 and CNE2 cells.

CONCLUSIONPSZ extract can induce methuosis in CNE1 and CNE2 cells by inducing the overexpression of Rac1.

OBJECTIVETo aimed at the establishment of mouse stably knockout of MYSM1 mesenchymal stem cell(MSC) line C3H10T1/2, and to investigate its immunological capacity of MSC in vitro.

METHODSTo establish the stably transfected MSC cell line by using CRISPR-Cas9 technology. Then the Flow cytometry, quantitative PCR and Western blot were employed to detect whether the MYSM1 have been knockout yet. Furthermore, the immune modulatory effect of MYSM1MSC was tested by addition of MYSM1MSC supernatant into spleen lymphocyte and Foxp3 culture. The mRNA expression of inflammatory cytokines such as interleukin-4, interferon-γ and interleukin-17 were detected by quatitatine PCR.

RESULTSThe expression of MYSM1 was steadily knock out in MSC. In addition, MYSM1MSC showed a stronger inhibitory effect on the expression of inflammatory cytokines. Therefore, the MYSM1 has been stably knocked out in C3H10T1/2.

CONCLUSIONThe mouse stably knockout of MYSM1 mesenchymal stem cells has been successfully established, the knock-out of MYSM1 in MSC can induce more potent immunosuppressive effects on cellular immune reaction in vitro. Our data laid a foundation for the further MSC-based applications in immune related diseases.

OBJECTIVETo explore the effects of the shock wave on the capacity of mesenchymal stem cells(MSCs) to proliferate and differentiate into osteoblasts.

METHODSMSCs were isolated from the bone marrow of healthy donors. The human bone marrow MSCs(BM-MSCs) were divided into 3 groups including blank control group,osteoinduced group and shock wave group. The MSCs in blank control group were cultured with common mediam; the MSCs in osteoinduced group were treated with osteogenic agents and cultured; the MSCs in shock wave group were cultured with common medium and stimulated by shock wave. The morphology of MSCs in each groups were observed by micoscopy; the CCK-8 was used to detect the proliferation ability of MSCs; the alkaline phosphatase staining and von Kossa staining were used to evaluale the differentiation potential of MSCs in each groups.

RESULTSThe results of CCK-8 revealed the shock wave could promote cell proliferation as compared with blank control group. The results of alkaline phosphatase and Von Kossa staining showed that the shock wave displayed a stronger ability to promote the human BMMSC differentiation into osteoblasts cells in comparison with the osteoinduced group. The blank control group was weakly positively stainined.

CONCLUSIONThe shock wave treatment can promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.

OBJECTIVETo isolate platelet-rich plasma(PRP) from the white slurry(WS), a depleted fraction of the clinical blood supply, so as to provide an easier method to harvest PRP for related studies and clinical use.

METHODSThe protocols preparing PRP from whole blood and WS were compared. The morphological characteristics of the different PRPs were observed under transmission electron microscope; the expression of the platelet markers CD41a and CD42b were detected by the flow cytometry. Moreover, the ingredients of the PRPs were measured by using cytoanalyzer. for detecting the physiological function of the PRP, the harvested PRP were added to MSC culture and the cell proliferation was detected by using CCK-8 method.

RESULTSa large amount of PRP from WS was easier harvested. the WS-derived PRP shared similar morphological characteristics and ingredients as compared with whole blood-derived PRP. Importantly, the WS-derived PRP exhibited a higher expression of CD41a and CD42b than that of traditional PRP, which indicate that the WS is a promising reservoir for PRP.

CONCLUSIONThe WS can be used to prepare PRP, and the novel PRP share similar biological characteristics as traditional PRP prepared from whole blood. The present study provides an easier and economical method to harvest PRP and this findings may be helpful for PRP related studies.

Objective To study the relativity between imageology and pathology during lung cancer,and estimate whether the lung cancer is preinvasive lesions,which can support evidences for the operation methods.Methods Clinical data of 624 patients who were diagnosed as lung adenocarcinoma and had solitary pulmonary nodule(diameter≤3 cm) were collected,all of them were scanned by thin layer CT scan(1 mm).The correlation between imageology and pathology data were analyzed.Results In 125 cases of GGO,the ratio of invasive lesions were 0 (0/72),6.1％ (3/49) and 100％ (4/4) in stage T1a,T1b and T1c respectively.In 285 cases of mGGO,if solid component was less than 0.5 cm,the ratio of invasive lesions were 1.7％ (1/58),6.9％ (2/29) and 50.0％ (2/4) in stage T~,T1b and Tic;but the ratio of invasive lesions were 81.3％ (13/16),94.1％ (96/102) and 97.4％ (74/76) respectively when the solid component was more than 0.5 cm.In 214 cases with solid nodules,the ratio of invasive lesions were 87.1％ (27/31),98.8％ (84/85) and 99.0％ (97/98) in stage T1 a,T1b and T1c.Conclusion The ratio of invasive lesions and solid component increased gradually along with the growing of tumor diameter in stage T1 lung cancer.CT imaging was highly correlated with the pathology diagnosis of preinvasive lesions and invasive lesions,which can be used as the guidance for operation methods.

OBJECTIVETo investigate the modulatory effect of the MSC derived from low attaching culture systems (suspending MSC) on T lymphocytes and the related mechanisms.

METHODSThe suspending MSC were generated from mouse compact bones by using low attaching plates and adherent cell culture flasks, respectively. The morphology of suspending MSC was observed under the inverted microscope and the cells were induced to differentiate into osteoblasts and adipocytes. Further, the surface antigen profile of MSC was analyzed with flow cytometry. In addition, the culture medium (CM) of suspending MSC and adherent MSC was collected and added into the activated T cell cultures before detection of the proliferation by CFSE assay. Moreover, the modulaory effects of the CM on the T cell-derived cytokines were detected by quantitative PCR. Also, the mRNA expression of cytokines of MSC was detected.

RESULTSThe suspending MSC grew in floating cell spheres and differentiated into osteoblasts and adipocytes in the induction medium. Furthermore, the suspending MSC shared the typical immuno-phenotype with their adherent counterparts. In addition, the results of CFSE assay demonstrated that suspending MSC derived CM suppressed ConA induced T cell proliferation. The results of quantitative PCR revealed that suspending MSC expressed transforming factor β1 and interleukin-6 at a higher level and suppressed the T cell expressing interferon γ and interleukine-17A.

CONCLUSIONThe suspending MSC exerted an unique modulatoy effect on T cells, which is quite different to adherent MSC.

Adipocytes ; cytology ; Animals ; Cell Adhesion ; Cell Culture Techniques ; Cell Differentiation ; Cell Proliferation ; Culture Media, Conditioned ; Flow Cytometry ; Immunophenotyping ; Interleukin-6 ; metabolism ; Lymphocyte Activation ; Mesenchymal Stromal Cells ; cytology ; Mice ; Osteoblasts ; cytology ; T-Lymphocytes ; cytology ; metabolism ; Transforming Growth Factor beta1 ; metabolism

Objective The aim of this study was to investigate how different concentrations of dextran sulfate sodi-um ( DSS) influence the establishment of mouse model of inflammatory bowel disease ( IBD) and the effect of DSS on the expression of colitis-associated immune factors.Methods The DSS solution in different concentrations (3%, 5%, 7%) were given to male C57BL/6J mice to generate mouse inflammatory bowel disease model.The IBD mice were observed by defecation characteristics, body weight, and survival time.The animals were sacrificed at 6 days after the start of DSS drinking.The general appearance of colons was observed and scored.Moreover, the pathological changes of the colon were examined and analyzed by routine histology.The expression of immune factors in the spleen was detected by real-time PCR.Results The mice in the 3%, 5%, 7% DSS groups developed murine colitis.In addition, the incidence of IBD and mouse mortality rate was directly proportional to the increase of DSS concentration.Furthermore, the higher concentra-tion of DSS induced the expression of proinflammatory factors including TNF-α, IFN-γand IL-17A, but cause a decrease of anti-inflammatory factors such as IL-4, IL-10 and Treg-related transcription factor Foxp3.Conclusions Our data suggest that giving 5%DSS solution to C57BL/6J mouse is appropriate to efficiently establish a murine IBD model.This laid an important foundation for further studies of the pathogenesis of IBD, biological characteristics, and intervention factors.

This study was purposed to establish a convenient and efficient method for isolating and culturing mouse bone marrow mesenchymal stem cells (MSC). The femurs and tibias of mouse were taken under sterile condition. MSC were isolated and cultured with flushing- out bone marrow or collagenase-digested bone fragment or bone marrow plus bone fragment. MSC colony number and size were compared. Immunophenotype and differentiation ability were tested to identify MSC. The results showed that colonies from bone marrow plus bone fragment group came out earliest and the colony number was 20 ± 4 at day 4; there were 11.5 ± 2.5 colonies in collagenase-digested bone fragment group and 9.5 ± 1.5 in flushing- out bone marrow group. The total cell yields of MSC after passaging showed best in bone marrow plus bone fragment group. Flow cytometry data showed the cultured cells expressed Sca-1, CD44 and CD29, not expressed pan-leukocyte surface marker CD45 and endothelial cell marker CD31. The isolated and cultured MSC could differentiate into osteoblast at the osteogenic differentiation condition, or adipocyte at adipogenic differentiation condition. It is concluded that the method of bone marrow plus bone fragment is convenient and efficient for isolating and culturing MSC.
Animals ; Bone Marrow Cells ; cytology ; Cell Culture Techniques ; methods ; Cell Separation ; methods ; Mesenchymal Stromal Cells ; cytology ; Mice ; Mice, Inbred C57BL