BACKGROUNDTransplantation of adult bone marrow-derived mesenchymal stem cells (MSCs) has been proposed as a strategy for cardiac repair following myocardial damage. However cell transplantation strategies to replace lost myocardium are limited by the inability to deliver large numbers of cells that resist peritransplantation graft cell death. Accordingly, we set out to isolate and expand adult swine bone marrow-derived MSCs, and to engineer these cells to overexpress AKT1 (protein kinase B), to test the hypothesis that AKT1-engineered MSCs are more resistant to apoptosis and can enhance cardiac repair after transplantation into the ischemic swine heart.

METHODSThe CDS (regulation domain of AKT1) AKT1-cDNA fragment was amplified, and MSCs were transfected following synthesis with a pCDH1-AKT1 shuttling plasmid. Western blotting analysis and real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed. Myocardial infarction (MI) models were constructed in Meishan pigs, and cardiac function was evaluated by magnetic resonance imaging (MRI) measurements and echocardiography 4 weeks later. All pigs were assigned to four groups: control (A), DMEM (B), MSC (C), and AKT-transfected (D). MSCs were transfected with the AKT1 gene, and autologous BrdU-labeled stem cells (1 x 10(7)/5 ml) were injected into left anterior descending coronary atery (LAD) of the infarct heart in groups C and D. In group B, DMEM was injected using the same approach. In group A, there was no injection following LAD occlusion. After 4 weeks, cardiac function and regional perfusion measurements were repeated by MRI and echocardiography, and histological characteristics of the hearts were assessed. Connecxin-43 (CX-43), BrdU, and von Willebrand factor (VWF) immunoreactivity was tested using enzyme linked immunosorbent assay (ELISA). Vascular endothelial growth factor (VEGF), transforming growth factor-beta1 (TGF-beta1) were analyzed at the same time.

RESULTSAKT1-cDNA was cloned into pCDH1-MCS1-EF1-copGFP and the sequence was confirmed. AKT mRNA expression was detected at 24 hours after transfection. AKT1 expression in MSCs remained strong after 2 weeks, according to real-time RT-PCR and Western blotting. Prior to cell implantation, end-diastolic left ventricular dimension (EDLVd) increased and stroke volume (SV) decreased in the MI hearts. MRI scans revealed significantly improved cardiac function following implantation, and implanted MSCs prevented thinning and expanding in the infarct region, as well as improved contraction and increased perfusion in all groups compared to control hearts. The left ventricular chamber size was smaller in cell-transplanted hearts than in control hearts. Moreover, group D exhibited significant improvement. The expression of CX-43, BrdU, and VWF could be found in the immunohistochemical pathological sections of group C and group D. The level of VEGF reached a high level 1 week after implanting the MSCs, but the level of TGF-beta1 decreased gradually.

CONCLUSIONSThe AKT1-expressing lentiviral vector resulted in stable over-expression of AKT1 in MSCs. MSC engraftment in host myocardium improved cardiac function by attenuating contractile dysfunction and pathological thinning of the infracted left ventricular wall, which likely resulted from myocardial regeneration and angiogenesis.

Animals ; Blotting, Western ; Disease Models, Animal ; Electrophoresis ; Genetic Vectors ; genetics ; Lentivirus ; genetics ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; metabolism ; Myocardial Infarction ; metabolism ; therapy ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Swine ; Ventricular Remodeling ; physiology

OBJECTIVETo assess the cytotoxicity of carbon-coated iron nanoparticles (CCIN) and epirubicin-loaded CCIN on Hep-G2 cells in vitro and compare the acute toxicities of epirubicin and epirubicin-loaded CCIN in mice.

METHODSThe cytotoxicities of CCIN and epirubicin-loaded CCIN on HepG2 cells were assessed using MTT assay, and the uptake of CCIN by the tumor cells was observed by optical and electron microscopy. Different doses of epirubicin and equivalent doses of epirubicin-loaded CCIN were injected intravenously in mice to compare their acute toxicities.

RESULTSOptical and electron microscopy revealed cytoplasmic uptake of CCIN in the tumor cells without obvious destruction of the cell structural integrity. Incubation of the HepG-2 cells with different concentrations of CCIN suspension did not result in significant variation in the mean absorbance. MTT assay showed reduced cytotoxicity of epirubicin-loaded CCIN in HepG2 cells as compared with that of epirubicin alone. The cell growth inhibition rate was significantly higher with epirubicin-CCIN mixture that contained a lower proportion of CCIN. In acute toxicity experiment with mice, the median lethal dose (LD(50)) of epirubicin was 16.9 mg/kg, while that of epirubicin-CCIN mixture was 20.7 mg/kg.

CONCLUSIONCCIN uptake by HepG-2 cells does not cause obvious cytotoxicity in vitro within a certain concentration range, epirubicin-loaded CCIN has reduced cytotoxicity against HepG2 cells as compared with epirubicin, and the cytotoxicity of the mixture decreases with the increase in the CCIN content in the mixture. Epirubicin delivery in mixture with CCIN can reduce its acute toxicity in mice.

Animals ; Antibiotics, Antineoplastic ; pharmacology ; toxicity ; Carbon ; pharmacology ; toxicity ; Drug Carriers ; pharmacology ; toxicity ; Epirubicin ; pharmacology ; toxicity ; Ferric Compounds ; pharmacology ; toxicity ; Hep G2 Cells ; Humans ; Iron ; pharmacology ; toxicity ; Mice ; Nanoparticles ; toxicity ; Toxicity Tests, Acute

OBJECTIVETo study the acute toxicity of carbon-coated iron nanocrystal (CCIN) in mice and its effects on hepatic, renal and hematological functions.

METHODSAcute toxicity of CCIN was evaluated by observing the toxic reactions in mice within 14 days following intravenous injection of different doses of CCIN particles. The liver and kidney functions and blood chemistry were tested in rats before and at different time points after CCIN injection.

RESULTSThe median lethal dose (LD(50)) of CCIN particles given by intravenous injection was 203.8 mg /kg in mice. Within the intravenous dose of 80 mg /kg injection, CCIN caused only mild alterations of the rats' biochemical and hematological indices that recovered without intervention in two weeks.

CONCLUSIONCCIN is characterized by low acute toxicity and mild side effects on the hepatic, renal and hematological functions within a certain dose range.

Animals ; Blood Chemical Analysis ; Carbon ; toxicity ; Iron ; administration & dosage ; toxicity ; Kidney ; drug effects ; physiopathology ; Liver ; drug effects ; physiopathology ; Male ; Mice ; Mice, Inbred BALB C ; Nanoparticles ; administration & dosage ; toxicity ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To explore the mediating role of doctor-patient relationship between occupational stress and job burnout of medical staffs involved in the prevention and treatment of patients with acquired immune deficiency syndrome(AIDS) and the regulating role of personality traits. METHODS: A total of 346 medical staffs who are involved in AIDS prevention and treatment from 29 antiviral treatment sites in Yunnan Province were selected as the study subjects using convenience sampling method. The Questionnaire of Doctor-Patient Interaction, Subscale of Feeling Stress, Questionnaire of Chinese Job Burnout, and China′s Big Five Personality Questionnaire(short version) were used to investigate these subjects. The mediating-regulating model was tested with the Process program. RESULTS: The total scores of doctor-patient relationship, occupational stress, personality traits and job burnout were(43.6±9.2),(153.1±29.5),(156.2±17.9) and(67.7±16.8), respectively. The job burnout was associated with doctor-patient relationship and occupational stress(correlation coefficients were-0.31 and 0.24, respectively, all P<0.05). Occupational stress had a direct effect on job burnout(P<0.01). The doctor-patient relationship had a mediating effect between occupational stress and job burnout(P<0.05), which accounted for 13.1% of the total effect. It was regulated by open personality traits(P<0.01). CONCLUSION: The doctor-patient relationship has a mediating effect between the occupational stress and job burnout of the medical staffs engaged in AIDS prevention and treatment, and the open personality traits plays a moderating role.

INTRODUCTIONMost hepatocellular carcinomas (HCC) develop in a background of underlying liver disease including chronic hepatitis B. However, the effect of antiviral therapy on the long-term outcome of patients with hepatitis B virus (HBV)-related HCC treated with chemoembolization is unclear. This study aimed to evaluate the survival benefits of anti-HBV therapy after chemoembolization for patients with HBV-related HCC.

METHODSA total of 224 HCC patients who successfully underwent chemoembolization were identified, and their survival and other relevant clinical data were reviewed. Kaplan-Meier and Cox regression analyses were performed to validate possible effects of antiviral treatment on overall survival (OS).

RESULTSThe median survival time (MST) was 15.9 (95% confidence interval [CI], 9.5-27.7) months in the antiviral group and 9.6 (95% CI, 7.8-13.7) months in the non-antiviral group (log-rank test, P = 0.044). Cox multivariate analysis revealed that antiviral treatment was a prognostic factor for OS (P = 0.008). Additionally, a further analysis was based on the stratification of the TNM tumor stages. In the subgroup of early stages, MST was significantly longer in the antiviral-treatment group than in the non-antiviral group (61.8 months [95% CI, 34.8 months to beyond the follow-up period] versus 26.2 [95% CI, 14.5-37.7] months, P = 0.012). Multivariate analysis identified antiviral treatment as a prognostic factor for OS in the early-stage subgroup (P = 0.006). However, in the subgroup of advanced stages, MST of the antiviral-treated group was comparable to that of the non-antiviral group (8.4 [95% CI, 5.2-13.5] months versus 7.4 [95% CI, 5.9-9.3] months, P = 0.219). Multivariate analysis did not indicate that antiviral treatment was a significant prognostic factor in this subgroup.

CONCLUSIONAntiviral treatment is associated with prolonged OS time after chemoembolization for HCC, especially in patients with early-stage tumors.

Antiviral Agents ; Carcinoma, Hepatocellular ; Chemoembolization, Therapeutic ; Drug Therapy, Combination ; Hepatitis B virus ; Hepatitis B, Chronic ; Humans ; Liver Neoplasms ; Mortality ; Neoplasm Staging ; Prognosis ; Retrospective Studies