ABSTRACT
Background and Aim: Cartilage disorders may deteriorate following oxidative stress injuries affecting mature chondrocytes. Meantime, mesenchymal stem cells [MSCs] can differentiate into chondrocytes in the presence of oxidative conditions and act as a source of compensation for injured chondrocytes. The present study aimed to investigate the effect of H2O2 on MSCs differentiation into chondrocytes in order to cast light on the dual roles of oxidative stress in the pathogenesis of diseases
Materials and Methods: Human mesenchymal stem cells were isolated from abdominal adipose tissue of three different donors and cultured in the presence of 50 microM H2O2 in order to differentiate into chondrocytes. We determined cell viability by tetrazolium assay and measured reactive oxygen species [ROS] level by flow cytometry. Presence of glycoseaminoglycans was confirmed by safranin staining
Results: The percentage of cells containing ROS was significantly higher in the cells treated with hydrogen peroxide [29.2% +/- 1] compared to that in the untreated control cells [7.7% +/- 1.4]. A significant increase in glycoseaminoglycan content was observed in H2O2 treated cells compared to that in the control cells both on the 9[th] day [treated: 1.57×104 +/- 0.1 vs control: 0.91×104 +/- 0.09] and 21[st] day [treated: 2.87×104 +/- 0.2 vs control: 0.96×104 +/- 0.07]. In addition, comparison of glycoseaminoglycan content on the 9[th] and 21[st] days showed a significantly higher content in both treated and control cells on the 21[st] day [p<0.05]
Conclusion: Hydrogen peroxide resulted in increased differentiation of adipose tissue-derived MSCs into chondrocytes. Therefore, we concluded that, oxidative stress had positive role in the induction of chondrocyte differentiation
ABSTRACT
High frequency of traumatic and non-traumatic brain injuries in one hand and improvement of the health care condition to restore patient's life in the other hand has increased the frequency of comatose patients in ICU. These patients often experience physical, cognitive, behavior or sensory defects, and the sensory input reduction in intensive care units expose them to cognition disorders. It seems that using sensory stimulation programs may be effective in preventing from sensory deprivation and facilitating recovery process. In this quasi-experimental study, 30 comatose patients who were hospitalized in ICU in Shariati and Sina hospitals were sought to be studied. The subjects were selected randomly using matching that was placed in case and control group. In the intervention group, patients received an auditory stimulation for 2 weeks, 6 days of a week, 2 times a day. The auditory stimulator was a recorded tape [5-10 minutes] of a familiar voice for 30 minutes. The Glasgow Coma Scale [GCS] was used for measuring the level of consciousness [LOC]. LOC was measured before and after each intervention 4 times a day. The control group LOC was measured in a similar manner to the case group. At the same time, homodynamic symptoms [blood pressure, pulse rate, and mean arterial pressure] were measured. Non-parametric test was used for analyzing data. The data was analyzed through SPSS V.11.5 computer software. The findings indicated that there was a significant difference in LOC of the intervention group at the first day and after fourteen days of the intervention [P<0.001], but not in the control group [P=0.769]. Although 2 groups were similar in LOC of the first day [P=0.605] but there were a significant difference between their LOC at the fourteenth day [P=0.001]. The results showed that the auditory stimulations with familiar voice were effective in increasing LOC in the comatose patients. It is suggested that nurses expose comatose patients with auditory stimulations using a recorded tape of familiar voice in ICU