BACKGROUND:Bone marrow mesenchymal stem cells (BMSCs) have been induced to differentiate into cardiomyocyte-like cells in vitro.OBJECTIVE:To explore the association between GATA-4, Nkx-2.5 and α-myosin heavy chain (α-MHC) expression and cell morphological changes and structure formation in the process of BMSCs differentiation into cardiomyocyte-like cells.METHODS:By using myocardial lysate, BMSCs were induced to differentiate into cardiomyocytes.Immunocytochemistry staining was used to detect cardiac troponin T (cTnT) and connexin43, for the identification of cardiomyocytes. In the process of directional differentiation, RT-PCR was used to detect the expression of GATA-4,Nkx2.5 and α-MHC.RESULTS AND CONCLUSION:During the directional differentiation of BMSCs, the cells were changed from long fusiform to short rod, forming protrusions that were interconnected to form mesh-like, bamboo-like or myotube-like structure. When the cells were interconnected like a bamboo, cTNT and connexin43 positive cells were visible, and then the number of positive cells increased with the presence of myotube-like structure. RT-PCR results showed that during the induced directional differentiation of BMSCs, GATA-4, Nkx2.5 and α-MHC mRNA levels increased continuously. When interconnected cells formed a mesh-like structure, GATA-4 expression reached the peak and then kept a high level. When adjacent cells were fused into a myotube-like structure, α-MHC reached the peak. Additionally, the expression of Nkx2.5presented a time-dependent increase trend. Overall, during the induced differentiation of BMSCs into cardiomyocyte-like cells, the expression of cardiomyocyte specific genes, characterized by temporality and spatiality, is related to the changes of cell morphology and special structure formation.

Objective To investigate the prevalence and clinical characteristics of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) in the First Affiliated Hospital of Chongqing Medical University. Methods Clinical isolates of S. aureus were collected from the hospital during the period from 2012 to 2015 and were tested for susceptibility to vancomycin using agar dilution method. The results were interpreted according to CLSI 2016 breakpoints. VISA and hVISA strains were screened out by population analysis profile-area under the curve (PAP-AUC). E-test was carried out to determine the MIC of VISA. The clinical data of the patients infected with S. aureus were reviewed retrospectively. Results A total of 105 patients were included in this analysis. And 105 strains of S. aureus were isolated from these patients, including methicillin-resistant S. aureus (MRSA) strains (58.1％, 61/105). PAP-AUC identified 19 (18.1％) hVISA strains and 10 (9.5％) VISA strains. Overall, 52 of the 105 patients were nosocomial infections and 53 community infections. The prevalence of MRSA was 69.2％ (36/52) in nosocomial infections, higher than that in community infections (47.2％, 25/53) (P＜0.05). The prevalence of hVISA in community infections (20.8％, 11/53) did not show significant difference from that in nosocomial infections (15.4％, 8/52) (P＞0.05). The clinical outcome (P＞0.05) and length of hospital stay (P＞0.05) did not show significant difference between hVISA and non-hVISA infections, or between VISA and non-VISA infections. Conclusions The prevalence of hVISA is high in this hospital, which does not show difference between S. aureus nosocomial infection and community infection, or between MRSA and MSSA. The length of hospital stay of hVISA infection is not significantly longer than that of nonhVISA infection. The clinical outcome of hVISA infection does not show difference from that of non-hVISA infection. Larger sample size is required to better understand the prevalence and clinical features of hVISA.

Objective To investigate the epidemiological and etiological characteristics of gram-negative bacilli (GNB) isolated from patients with intra-abdominal infection (IAI). Methods The patients with abdominal infection were identified retrospectively during the period from 2011 to 2015. The clinical and microbiological data were analyzed by WHONET 5.6 and SPSS 20.0. Results A total of 478 cases of IAI [hospital-acquired (HA) 290 cases, community-acquired (CA) 188 cases] were included in this analysis. CA-IAI patients at low risk were associated with significantly better outcome, and lower acute physiology and chronic health evaluation (APACHE) Ⅱ score and sequential organ failure assessment (SOFA) score than the CA-IAI and HA-IAI patients at high risk. The most common gram-negative bacillus isolated from intra-abdominal infections was E. coli and K. pneumoniae. The prevalence of ESBLs-producing E. coli and K. pneumoniae isolates was 75.8％ and 35.8％, respectively. The E. coli isolates remained highly susceptible to amikacin, piperacillin-tazobactam, and carbapenems during the 5-year period, while the K. pneumoniae isolates showed poorer susceptibility to ampicillin-sulbactam. Conclusions The prevalence of ESBLs-producing GNB is increasing in the patients with IAI. Such isolates were resistant to commonly used antimicrobial agents, but generally susceptible to carbapenems. It is important to strengthen the monitoring of antimicrobial resistance in IAIs, and choose antimicrobial therapy rationally based on the results of antimicrobial susceptibility test.

Objective: To examine the regulatory effect of ginsenoside Rg1 (G-Rg1) on endoplasmic reticulum stress and its effect on hepatocellular apoptosis in carbon tetrachloride (CCl₄)-induced acute liver failure (ALF). Methods: Forty healthy, adult male C57/BL mice were randomly divided into normal saline control (NS) group, G-Rg1 blank control (G-Rg1) group, CCl₄ model (CCl₄) group, and G-Rg1 preventive treatment (CCl₄+G-Rg1) group, and an ALF mouse model was established by CCl₄ induction. Blood and liver specimens were collected from all mice upon sacrifice at 12 hours post-intraperitoneal injection. Serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST) and total bilirubin (TBil) levels were determined using commercial test kits. The mRNA expression of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) was measured using real-time PCR. The protein expression of GRP78, CHOP, caspase12, and caspase3 were measured by Western blot. Histological changes in the liver were assessed by hematoxylin-eosin staining, and the expression of GRP78 and caspase3 was detected by immunohistochemistry. Hepatocyte apoptosis was determined using terminal transferase dUTP nick end labeling. Quantitative data were analyzed using one-way ANOVA, and subsequent pairwise comparisons were performed using the LSD-t method. Results: Serum ALT, AST, and TBil levels in the CCl₄+G-Rg1 group were significantly reduced compared with those in the CCl₄ group (ALT: 691.30 ± 108.06 U/L vs 980.66 ± 110.29 U/L, F = 365.07, P < 0.05; AST: 195.40 ± 15.41 U/L vs 319.44 ± 89.32 U/L, F = 115.64, P < 0.05; TBil: 1.09 ± 0.11 mg/dl vs 1.56 ± 0.12 mg/dl, F = 211.29, P < 0.05). The relative mRNA expression of GRP78 and CHOP was significantly lower in the CCl₄ + G-Rg1 group than in the CCl₄ group (P < 0.05). The relative protein expression of caspase3, GRP78, caspase12, and CHOP was significantly reduced to different extents in the CCl₄+G-Rg1 group compared with those in the CCl4 group (P < 0.05). The CCl₄ + G-Rg1 group showed reduced liver tissue degeneration and necrosis compared with the CCl₄ group. Furthermore, the CCl₄+G-Rg1 group showed significantly fewer brown granules in the liver than the CCl4 group (P < 0.05), indicating that G-Rg1 preventive treatment reduced CCl₄-induced hepatocyte apoptosis. Conclusion G-Rg1 prophylaxis can inhibit inflammation and reduce hepatocyte necrosis and apoptosis during CCl₄-induced ALF. Its mechanism may involve the suppression of endoplasmic reticulum stress-related signaling molecules to alleviate hepatocyte endoplasmic reticulum stress and apoptosis. The results of this study suggest that G-Rg1 may inhibit liver inflammation and hepatocyte apoptosis through multiple targets to protect liver function.

Objective:To explore the impacts of workload and expected income index on the salary satisfaction of medical staff at public hospitals.Methods:From October 15th to November 10th, 2020, the salary system reform monitoring questionnaire for medical staff in public hospitals formulated by development center for medical science & technology National Health Commission was adopted to evaluate the workload, actual income, expected income and salary satisfaction of 120 pilot public hospitals for salary reforms in 21 cities (prefectures) in Sichuan province. The questionnaire survey was conducted among 8 651 medical staff of these hospitals. Descriptive analysis was carried out on the results of the questionnaire; the ratio of expected income to actual income, namely the expected income index, was used to reflect the relative difference between expected income and actual income; χ2 test and binary logistic regression were used to analyze the influencing factors of salary satisfaction. Results:8 133 valid questionnaires were recovered. The average working time per week of the survey subjects was 48.17 hours, and the average longest continuous working time was 15.30 hours; 85.63% (6 964) of the medical staff had expected income index greater than 1. The average score of salary satisfaction was 58.22 points and 57.72% (4 694) of the medical staff were dissatisfied. The longer the continuous working time (16-72 h versus 8-9 h, OR=0.755), the greater the expected income index (>1 versus =1, OR=0.522), and the lower the salary satisfaction. Conclusions:The workload of medical staff was heavy, the salary failed to meet the expected level, the sense of satisfaction was low. It is suggested to monitor in real time and dynamically adjust the workload of medical staff in combination with the actual situation, formulate the salary level in line with the technical labor value of different medical staff, and establish a comprehensive performance appraisal mechanism.