Propofol improves intestinal ischemia-reperfusion injury in rats through NF-κB pathway

OBJECTIVE

The aim of this study was to investigate the effects of propofol on intestinal ischemia-reperfusion injury in rats through the nuclear factor-kappa B (NF-κB) pathway.

MATERIALS AND METHODS

A total of 24 Sprague-Dawley rats were selected and randomly divided into three groups, including sham operation group, ischemia group and propofol group. Rats in sham operation group were only treated with isolation of superior mesenteric artery, which was clipped for 1 h and reperfused for 2 h in ischemia group. Meanwhile, propofol (60 mg/kg) was injected into the femoral vein 1 h before ischemia in propofol group. TUNEL assay was performed to detect cell apoptosis of intestinal tissues. Real-time quantitative polymerase chain reaction (RT-qPCR) was conducted to measure the expression levels of malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO), caspase-3 and B-cell lymphoma-2 (Bcl-2) in rats of each group. Western blotting was utilized to detect the protein expression levels of NF-κB pathway related molecules, such as myeloid differential protein-88 (MyD88), v-rel avian reticuloendotheliosis viral oncogene homolog A (RelA) and NF-κB. Furthermore, changes in plasma cytokine levels were determined via enzyme-linked immunosorbent assay (ELISA).

RESULTS

The number of apoptotic cells in ischemia group was remarkably higher than that in sham operation group (p<0.05). However, it decreased notably in propofol group compared with ischemia group (p<0.05). In comparison with sham operation group, significantly up-regulated expression of caspase-3 and down-regulated expression of Bcl-2 were observed in the intestinal tissues of rats in ischemia group (p<0.05). Caspase-3 was lowly expressed, while Bcl-2 was highly expressed in the intestinal tissues of rats in propofol group compared with ischemia group (p<0.05). In addition, no statistically significant differences were observed in the expression level of SOD among sham operation group, ischemia group and propofol group (p>0.05). The expression levels of MDA and MPO were overtly higher in the intestinal tissues of rats in ischemia group than those in sham operation group and propofol group (p<0.05). Besides, the protein expression levels of MyD88, RelA and NF-κB in the intestinal tissues of rats in ischemia group were remarkably higher than those in sham operation group and propofol group (p<0.05). The activity of the NF-κB pathway in the intestinal tissues of rats in propofol group significantly declined compared with ischemia group (p<0.05). Moreover, compared with sham operation group, plasma levels of TNF-α, interleukin (IL)-2, IL-6 and IL-4 increased significantly in rats of ischemia group (p<0.05). However, they were markedly lower in propofol group than those in ischemia group (p<0.05).

CONCLUSIONS

Propofol protects rats from intestinal ischemia-reperfusion injury through the NF-κB pathway.

[Effects of occupational cadmium exposure on workers' cardiovascular system]

Objective: To investigate the effects of cadmium exposure on cardiovascular system of occupational workers. Methods: Cross-sectional study was applied to 992 workers in a nickel-cadmium battery plant in November, 2011, of which 749 were cadmium exposed workers and 243 were controls without cadmium and other expose. Urinary cadmium、electrocardiogram (ECG) and blood pressure were examined simultaneously among 992 workers. The risk factors of ECG abnormality rate and hypertension rate were analyzed by Logistic regression. Results: The level of urinary cadmium in cadmium exposed workers was significantly higher than controls (8.89±4.00 vs 1.34±1.18 μg/g creatinine, P<0.01) . Urinary cadmium level in women was significantly higher than men in both exposure and control group (P<0.05) . According to the group of working years, Urinary cadmium level raised with the increase of working years (F=28.272, P<0.001) . The ECG abnormality rate and hypertension rate of cadmium exposed workers were higher than that of control group, the differences were all statistically significant (P<0.01) . The abnormal rate of ECG and the hypertension rate increased with the prolonging of working years and demonstrated dose-response relationship. With the increase of urinary cadmium level, the abnormal rate of ECG and hypertension rate raised (OR=1.11, P<0.01) and (OR=1.15, P<0.01) respectively. Conclusion: Occupational cadmium exposure increased the abnormal rate of ECG and blood pressure and therefore damaged cardiovascular system of workers. This study provided base data for protecting health of cadmium exposed workers.

Effects of Sirtuin 1 on the proliferation and osteoblastic differentiation of periodontal ligament stem cells and stem cells from apical papilla

The function of SIRT1 in the proliferation and osteoblastic differentiation of dental stem cells is unclear. The aim of this study was to assess the roles of SIRT1 in these processes using periodontal ligament stem cells (PDLSCs) and stem cells from apical papilla (SCAPs). A defined concentration of resveratrol, an SIRT1 activator, or nicotinamide, an SIRT1 inhibitor, was administered to PDLSCs, SCAPs, and a mixed group of the two cell lines, and their effects on these processes analyzed. Cell proliferation was tested using microtitration with a tetrazolium dye (MTT). Alkaline phosphatase (ALP) activity, mineralization ability, and the expression of osteoblastic differentiation-associated genes were assessed as well. These studies demonstrated that resveratrol could promote cell proliferation of all three groups in a gradually increasing trend over time. In contrast, nicotinamide suppressed the proliferation of the three cell lines. The results also showed that the markers of osteoblastic differentiation: ALP activity, mineralization ability, and the expression levels of the osteoblastic genes ALP, osteopontin, osteocalcin, and bone sialoprotein, were enhanced in the groups with resveratrol treatment. In contrast, following addition of nicotinamide, ALP activity, mineralization ability, and the expression levels of the osteoblastic genes were down-regulated in the cells. Together, these results suggest that the SIRT1 activator and inhibitor compounds, resveratrol and nicotinamide, function at high efficiency in adjusting cell proliferation, and that SIRT1 is a powerful regulator of osteoblastic differentiation of PDLSCs and SCAPs. In addition, co-culture of the two cell lines could promote their abilities of proliferation and osteogenic differentiation.

Maximum-biomass concentration prediction for Bifidobacteria in the pH-controlled fed-batch culture

Our objective was to systematically study the relationship between maximum biomass concentration of different Bifidobacteria and total-acid anions accumulation, and develop a prediction equation for the maximum biomass concentration in the fed-batch culture at pH-controlled 7·0. The accumulation of acid anions and the consumption of nutrients of various strains were evaluated. In addition, minimum inhibitory concentrations (MICs) of acid anions on a range of strains were examined at pH 7·0. The inhibition of acid anions, which had the same MIC as sodium chloride, was due to the osmotic pressure under pH 7·0 conditions. Moreover, the concentration of total-acid anions completely inhibiting each strain in the fed-batch culture at pH-controlled 7·0 had no significant differences with the MIC of acid anions for the corresponding strains. The osmotic pressures under two conditions were not significantly different. Finally, the maximum biomass concentration of Bifidobacteria was found to be closely related to biomass yield per unit of acid anion produced (YX/P ) and MIC (C) which were needed for the prediction, and different strains exhibited marked correlation (P ˂ 0·01, R = 0·985). An equation for the prediction of the maximum biomass concentration was developed as follows: Xmax -X0  = (0·71 ± 0·03)·YX/P ·C.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides further insights into the inhibition of Bifidobacteria by dissociated acid anions (the dissociated form) at pH 7·0. The high correlation between different strains suggested that the equation established in this paper is appropriate for different strains of Bifidobacteria. The prediction equation could be used to guide practical production in the preparation of materials, the control of the end of fermentation and production plans for further products such as freeze-dried powder of Bifidobacteria or food fermentation.

[Study on the release mechanism of fenoprofen calcium from hydrophillic sustained-release matrix]

AIM

To study the release mechanism of fenoprofen calcium (FC) from hydroxypropylmethylcellulose (HPMC) matrices.

METHODS

The release of FC and the erosion properties of hydrophillic matrices containing HPMC was examined at different paddle speed. The release mechanism of FC was further confirmed by evaluating the n value in Peppas equation.

RESULTS

The results indicate that the release of FC and the erosion of matrices exhibit zero order kinetic equation, and it exhibits line relationship between them.

CONCLUSION

In the first 40 min, FC mainly released by diffusion and erosion from HPMC matrix, while it was controlled by the rate of tablet erosion after 50 min.