Embryonic stem cell (ESC) is a kind of stem cell with self-renewal capability and developmental luripotency,which is at the early stage of embryonic development,and it is the original cell of various kinds of tissue and organ.Under certain conditions,ESCs can maintain an undifferentiated state,long-term surviving and infinite breeding state in vitro.The research of tberapeutic effect of ESCs in animal disease model,especially in ouse,has made great progress.On the basis of this research,researchers attempt to use ESCs for the clinical therapy of various diseases,and investigate the feasibility and security of this kind of therapy.Currently ESCs have been used in the therapy of diabetes mellitus,Parkinson's disease and cardiovascular injury.Even though many problems of technique and ethics should be done,we believe that ESC therapy will be a promising method and used in linical practice if we make clear the mechanism of ESC directional differentiation,establish an optimal culture system,and solve the problem of oncogenicity.

Objective To study the effects of human insulin-like growth factor 1(hIGF-1) gene transfection on the proliferation of NIH3T3 fibroblasts.Methods The plasmid of pcDNA3.1-hIGF-1 was transfected into NIH3T3 fibroblasts by using Lipofectin method.The positive cell clones were selected with G418 and cultured for 4 weeks.The stable expression of hIGF-1 in the positive cells was determined by in situ hybridization and immunocytochemical analysis.MTT assay and flow cytometer analysis were used to observe the proliferation of NIH3T3 fibroblasts.Results hIGF-1 mRNA and protein expressed in NIH3T3 fibroblasts transfected with pcDNA3.1-hIGF-1 by in situ hybridization and immunocytochemical analysis.MTT assay showed the A value of transfected NIH3T3 fibroblasts rose,compared with untransfected NIH3T3 fibroblasts group,the difference was significant(P

Objective:To assess if metagenomic next-generation sequencing (mNGS) of periprosthetic joint tissue can provide an alternative rapid and sensitive tool for the diagnosis of prosthetic joint infection (PJI), especially compared to microbiological culture.Methods:A total of 33 eligible patients who underwent revision arthroplasty from June 2019 to June 2020 in orthopedic surgery department of the first affiliated hospital of Zhengzhou University were retrospectively analyzed. Twenty-one patients were included in PJI group according to the American Academy of Musculoskeletal Infection diagnostic criteria, with 17 cases of knee and 4 cases of hip, including 9 cases of male and 12 cases of female, with an average age of 59.14±14.55 years old (range from 28 to 84), and an average BMI of 23.7±2.8 kg/m 2 (range from 17.7 to 29.4 kg/m 2). Twelve patients were included in aseptic loosening group (control group), with 4 cases of knee and 8 cases of hip, including 4 cases of male and 8 cases of female, with an average age of 53.08±10.05 years old (range from 39 to 70), and an average BMI of 25.2±2.9 kg/m 2 (range from 18.3 to 31.2 kg/m 2 ). Microbiological culture results of synovial fluid and periprosthetic joint tissue and mNGS results of periprosthetic joint tissue were collected. The sensitivity and specificity of mNGS and microbiological culture were calculated and compared. The species of pathogenic microorganismsdetected by the two techniques were summarized. In addition, the impact of antibiotic use on the efficacy of both techniques were compared. Results:mNGS detected 13 positive cases and microbiological culture detected 6 positive cases in the PJI group. In the aseptic loosening group, 1 case was determined positive by mNGS, and all the microbiological culture results were negative. In the diagnosis of PJI, mNGS showed significantly higher sensitivity than that of culture (61.9% vs 28.6%, χ2=4.71, P=0.03), while no statistical difference was observed in terms of specificity (91.7% vs 100%, χ2=1.04, P=0.31). In the PJI cases with prior exposure to antibiotics within two weeks, the sensitivity of mNGS was significantly higher than that of culture (53.8% vs 15.4%, χ2=4.25, P=0.04). However, there was no significant difference in the sensitivity between mNGS and culture in patients without antibioticsexposure (66.7% vs 44.4%, χ2=0.90, P=0.34). In the detection of pathogenic microorganism, mNGS detected 9 kinds of bacteria (Staphylococcus aureus, Staphylococcus family, Moraxella Oslo, Propionibacterium acnes, Streptococcus acnes, Staphylococcus epidermidis, Mycobacterium tuberculosis, Staphylococcus Lyons, Bacteroides fragilis) and 2 kinds of fungi (Aspergillus fumigatus, Candida parapsilosis), while microbiological culture detected 3 kinds of bacteria (Staphylococcus aureus, Moraxella catarrhalis, Mycobacterium tuberculosis) and one kind of fungi (Candida parapsilosis). mNGS and microbiological culture were both positive in 5 cases, among which 3 cases had completely matched results (Staphylococcus aureus, Mycobacterium tuberculosis, Candida parapsilosis), one case had partly matched results (mNGS detected more bacteria than culture) and one case had totally mismatched results. Additionally, in the diagnosis of the 3 included tuberculous PJI, mNGS showed 100% specificity and sensitivity. Conclusion:mNGS of periprosthetic joint tissue is a more powerful tool for diagnosis and pathogen detection of PJI compared to microbiological culture, especially in the diagnosis of tuberculosis PJI. Besides, mNGS is more resistant to antibiotic exposure than culture.

Objective:To investigate the relationship between preoperative serum thyroglobulin (Tg) and clinical data with the risk of cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC) .Methods:Data of 395 PTC patients who underwent surgery from Feb. 2016 to Jun. 2019 at the Second Affiliated Hospital of Soochow University were retrospectively analyzed. Based on whether cervical lymph nodes had metastasis, patients were classified into central lymph node metastasis positive group ( n=195 cases) , central lymph node metastasis negative group ( n=200 cases) , lateral lymph node metastasis positive group ( n=72 cases) , and lateral lymph node metastasis negative group ( n=323 cases) .Then the relationship between age, sex, multifocality, tumor diameter, capsular invasion, preoperative TSH and preoperative Tg with lymph node metastasis were analyzed by SPSS. Comparisons between groups were performed by χ2 test and rank sum test. Prediction efficiency of the preoperative Tg and Logistic regression model was estimated by receiver operating characteristic (ROC) curve. A total of 100 PTC patients confirmed by pathological results in the Second Affiliated Hospital of Soochow University from Jul. 2019 to Apr. 2020 were selected as the validation data. Results:Multi-factor Logistic regression showed that age, tumor diameter, capsular invasion and preoperative Tg were independent risk factors of central cervical lymphatic metastasis ( P<0.05) ; Tumor diameter, capsular invasion, central cervical lymphatic metastasis and preoperative Tg were independent risk factors of lateral cervical lymphatic metastasis ( P<0.05) . The area under the ROC curve (AUC) for diagnosing central lymph node metastasis by preoperative Tg was 0.710, with a sensitivity of 49.2%, and specificity of 88.5%. The AUC for diagnosing lateral lymph node metastasis by preoperative Tg was 0.728, with a sensitivity of 59.7%, and specificity of 89.5%. The AUC for diagnosing central lymph node metastasis by the prediction model was 0.773, with a sensitivity of 78.5%, and specificity of 64.5%.The AUC for diagnosing lateral lymph node metastasis by the prediction model was 0.869, with a sensitivity of 84.7%, and specificity of 70.3%. Conclusions:The preoperative serum Tg level is correlated with cervical lymph node metastasis in PTC patients. But the Logistic regression model based on preoperative Tg and other independent risk factors shows a better predictive value.