ABSTRACT
Objective:To explore the protective effect of methyl eugenol (Me) on islet ischemia/reperfusion (I/R) injury and elucidate its underlying mechanism.Methods:The islets were isolated and purified from 6-8 week male BALB/c mice and divided into four groups of normal control (normal culture without any treatment), hypoxia/reoxygenation (H/R treatment), H/R+ dimethyl sulfoxide (DMSO dosing plus H/R treatment) and H/R+ Me (Me dosing plus H/R). Viability of islet cells in each group was detected by acridine orange (AO)/propidium iodide (PI) double stain.Function of islet cells (insulin secretion) was measured by enzyme-linked immunosorbent assay (ELISA). Murine islet β Min6 cells were selected for detecting the effect of Me on the proliferative activity of normal cultured and H/R treated islet cells under different concentration gradients by CCK8.Then Min6 cells were divided into four groups of normal, H/R, H/R+ DMSO and H/R+ Me.The definition of group was the same as that of primary murine islets.Flow cytometry and Hoechst 33342 nuclear stain were utilized for detecting cell apoptotic rate in each group.The protein expressions of p-JNK, p-p38, JNK, p38, Bcl-2 and Bax were detected by Western blot.And the data were processed by one-way ANOVA or t test.Results:The proportion of dead islet cells in H/R group was (29.47±2.65)% and it was significantly lower than that in normal group (7.63±1.53)%.And the inter-group differences were statistically significant ( P<0.001). The proportion of dead islet cells was (20.63±3.07)% in H/R+ Me group.It was higher than that in H/R group (29.47±2.65)% and in H/R+ DMSO group (30.13±1.50)% and inter-group difference was statistically significant ( P<0.05 & P<0.01). Under the stimulation of high glucose, the insulin secretion level of islet in H/R+ Me group was (1.76+ 0.08) mg/L, which was higher than that in H/R group and H/R+ DMSD group(1.24±0.14)mg/L and(1.27±0.05)mg/L, and the difference was statistically significant[(1.76±0.08) vs. (1.24±0.14) mg/L; (1.76±0.08) vs.(1.27±0.05) mg/L, P<0.01]. There was no significant effect on cell viability after Me dosing within a certain concentration range (0-40 μmol/L). After Me dosing (5 μmol/L), cell viability of H/R-treated Min6 cells was significantly higher than that without Me.And the difference was statistically significant[(1.19±0.03) vs.(1.00±0), P<0.01]. As compared with H/R and H/R+ DMSO groups, overall apoptotic rate declined in H/R+ Me group (Hoechst 33342 stain: 14.50%±1.05% vs. 23.30%±1.18%, 14.50%±1.05% vs. 22.77%±1.75%, P<0.001; Flow cytometry: 4.36%±0.54% vs. 21.44%±1.02%, 4.36%±0.54% vs. 21.68%±3.06%, P<0.01). The expressions of p-JNK and p-p38 were down-regulated (p-JNK: 0.77±0.06 vs. 1.03±0.05, 0.77±0.06 vs.0.93±0.04, P<0.001; p-p38: 0.80±0.05 vs. 1.01±0.08; 0.80±0.05 vs. 1.00±0.05, P<0.05) while Bcl-2/Bax ratio rose (1.62±0.13 vs. 0.72±0.10, 1.62±0.13 vs. 0.74±0.13, P<0.01). Conclusions:Me can improve the viability and function of islets and suppress the apoptosis of Min6 cells after H/R.The mechanism is correlated with JNK and p38 MAPK signaling pathways.
ABSTRACT
Objective To investigate the attitude and willingness of nurses from intensive care unit (ICU) in Chongqing towards organ donation and analyze the influencing factors. Methods In this study, 4 Grade 3A hospitals with organ transplantation qualifications in Chongqing were selected by cluster sampling, and 321 nurses in ICU from these 4 hospitals were chosen by convenient sampling method to complete the questionnaire survey. The scores of ICU nurses' attitude and willingness towards organ donation were calculated. Spearman's correlation analysis was adopted to analyze the correlation between the attitude and willingness to donate organs. Multiple linear regression analysis was performed to identify the influencing factors of attitude and willingness towards organ donation. Results The average score of ICU nurses' attitude toward organ donation was (3.5±0.9) and the median score of willingness to donate organs was 2 (2-3). The attitude of ICU nurses towards organ donation was positively correlated with their willingness (P < 0.001). The experience of voluntary blood donation, the attitude of family members towards organ donation and the experience of organ donation persuasion were the influencing factors of ICU nurses' willingness to donate organs (all P < 0.05), among which the experience of voluntary blood donation and the attitude of family members towards organ donation were also the influencing factors of ICU nurses' attitude towards organ donation (both P < 0.05). Conclusions ICU nurses hold neutral attitude towards organ donation and show low willingness to donate organs. The experience of voluntary blood donation, the attitude of family members towards organ donation and the experience of organ donation persuasion are the main influencing factors.