Exosomes derived from mesenchymal stem cells are a class of discoid extracellular vesicles with a diameter of 40—100 nm discovered in recent years. They contain abundant nucleic acids, proteins and lipids, and have abundant biological information. Exosomes derived from mesenchymal stem cells regulate cell activities by acting on receptor cells, and promote regeneration of many tissues, such as bone, cartilage, skin, intervertebral disc, and spinal nerves. Studies have shown that exosomes derived from mesenchymal stem cells have similar biological functions as mesenchymal stem cells, and are more stable and easier to be preserved. Therefore, they have been increasingly applied in the field of orthopedic tissue repair in recent years. This paper reviews the application of exosomes derived from mesenchymal stem cells in orthopedics.
Objective To elucidate the etiology of DNA impairment of type Ⅱ alveolar epithelial cells(AT-II) of the rats fed with low selenium and high cadmium fodder，and the effect of Vitamin C.Methods With single cell gel electrophoresis technique，we observed the joint action of selenium，cadmium and vitamin C on DNA damage in AT-II cells of the eight groups of rats fed separately with：normal （2 groups），high Cd，high Cd+high VC，low Se+high Cd，low Se+high Cd+high VC，high Se+high Cd and high Se+high Cd+high VC fodder for 14 weeks.Results Compared with the control，there was no DNA changes have been observed in the high Se+high Cd+high VC group.However，in the high Se+high Cd group and high Cd+high VC group，DNA damage of AT-II cells can be detected clearly；in the low Se+high Cd+high VC group and high Cd group，the degree of the DNA damage is more serious than the above two groups；in the low Se+high Cd group，the extent of the DNA damage was the most serious on all of the groups be studied.Conclusion It is suggested that Se deficiency and simultaneously Cd overabundance may damaged DNA of AT-II cells of the rats significantly，however，Vitamin C may protect AT-II against the injury effectively.
ObjectiveTo separate peripheral blood mesenchymal stem cells (PBMSC) and peripheral blood endothelial progenitor cells (PBEPC) from peripheral blood, and investigate the biological characteristics of composite cell sheets of PBMSC and PBEPC.MethodsThe peripheral blood of healthy adult New Zealand white rabbits was extracted and PBMSC and PBEPC were separated by density gradient centrifugation. Morphological observation and identification of PBMSC and PBEPC were performed. The 3rd generation of PBMSC and PBEPC were used to construct a composite cell sheet at a ratio of 1∶1, and the 3rd generation of PBMSC was used to construct a single cell sheet as control. The distributions of cells in two kinds of cell sheets were observed by HE staining. In addition, the expression of alkaline phosphatase (ALP), osteocalcin (OCN), and vascular endothelial growth factor (VEGF) in the supernatants of cell sheets were observed by ELISA at 1, 5, and 10 days after osteogenic induction.ResultsThe morphology of PBMSC was spindle-shaped or polygonal, and PBMSC had good abilities of osteogenic and adipogenic differentiation. The morphology of PBEPC was paved stone-like, and the tube-forming test of PBEPC was positive. Two kinds of cell sheets were white translucent. The results of HE staining showed that the composite cell sheet had more cell layers and higher cell density than the single cell sheet. The expressions of ALP, OCN, and VEGF in the supernatant of the two groups of cell sheets increased with the time of induction. The expression of OCN in the group of composite cell sheet was significantly higher than that in the group of single cell sheet on the 5th and 10th day, ALP on the 10th day was significantly higher than that in the group of single cell sheet, VEGF expression on the 1st, 5th, and 10th day was significantly higher than that in the group of single cell sheet, all showing significant differences (P<0.05), and there was no significant difference between the two groups at other time points (P>0.05).ConclusionPBMSC have stable differentiation ability, and they have good application prospects because of their minimally invasive access. Composite cell membranes constructed by co-culture of two kinds of cells and induction of membrane formation provides a new idea and exploration for tissue defect repair.
ObjectiveTo investigate the estimated prevalence of depression and its associated factors among inpatients in the Department of Oncology in general hospitals. MethodsOn October 29th, 2013, we surveyed all hospitalized patients from the Department of Oncology in West China Hospital, Sichuan University. The questionnaire on patients’ demographic characteristics and the Patient Health Questionnaire-9 (PHQ-9) were combined to form one questionnaire to investigate the incidence of depression in hospitalized patients in general hospitals and its influencing factors. ResultsWe gave out 546 questionnaires and retrieved 528 with a retrieval rate of 96.6%. Seven questionnaires had 15 or more empty items and were deleted. The final number of valid questionnaires was 521, with a validity rate of 95.4%. The estimated prevalence of depression among inpatients from the Department of Oncology was 32.8% (171/521). Risk factors for depression in patients in the Department of Oncology included female gender [OR=1.550, 95%CI (1.034, 2.325), P=0.034] illiterate and primary school education [OR=2.534, 95%CI (1.329, 4.832), P=0.005] and annual household income lower than 10 000 RMB [OR=1.850, 95%CI (1.056, 3.243), P=0.032]. A total of 135 patients had suicidal risks, among whom 90 (52.6%) had depression, and Spearman correlation analysis showed that suicidal risk was moderately and positively correlated with PHQ-9 scores (r=0.558, P<0.001). ConclusionsThe estimated total prevalence of depression is high in hospitalized patients in the Department of Oncology, especially in female, low educational level and low family income patients. We must pay more attention to the mental health of cancer patients, evaluate depression and suicidal tendency carefully and provide psychological service timely.