Genistein attenuates isoflurane-induced neurotoxicity and improves impaired spatial learning and memory by regulating cAMP/CREB and BDNF-TrkB-PI3K/Akt signaling

Anesthetics are used extensively in surgeries and related procedures to prevent pain. However, there is some concern regarding neuronal degeneration and cognitive deficits arising from regular anesthetic exposure. Recent studies have indicated that brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are involved in learning and memory processes. Genistein, a plant-derived isoflavone, has been shown to exhibit neuroprotective effects. The present study was performed to examine the protective effect of genistein against isoflurane-induced neurotoxicity in rats. Neonatal rats were exposed to isoflurane (0.75%, 6 hours) on postnatal day 7 (P7). Separate groups of rat pups were orally administered genistein at doses of 20, 40, or 80 mg/kg body weight from P3 to P15 and then exposed to isoflurane anesthesia on P7. Neuronal apoptosis was detected by TUNEL assay and FluoroJade B staining following isoflurane exposure. Genistein significantly reduced apoptosis in the hippocampus, reduced the expression of proapoptotic factors (Bad, Bax, and cleaved caspase-3), and increased the expression of Bcl-2 and Bcl-xL. RT-PCR analysis revealed enhanced BDNF and TrkB mRNA levels. Genistein effectively upregulated cAMP levels and phosphorylation of CREB and TrkB, leading to activation of cAMP/CREB-BDNF-TrkB signaling. PI3K/Akt signaling was also significantly activated. Genistein administration improved general behavior and enhanced learning and memory in the rats. These observations suggest that genistein exerts neuroprotective effects by suppressing isoflurane-induced neuronal apoptosis and by activating cAMP/CREB-BDNF-TrkB-PI3/Akt signaling.

Investigation on occupational stress of radiation exposed workers in Guangdong Province / 中国职业医学

OBJECTIVE: To investigate the occupational stress level of radiation exposed workers in Guangdong Province and explore the factors that influence occupational stress. METHODS: By random sampling method,306 radiation workers of Guangdong Province were selected in this study. The simplified Chinese version of Effort-Reward Imbalance( ERI)questionnaire was used to assess occupational stress levels. The scores of 3 dimensions including external effort,reward and internal commitment and their differences were analyzed. RESULTS: The scores of external effort,reward and internal commitment of 306 radiation workers in this study were( 15. 83 ± 5. 18),( 46. 63 ± 9. 06) and( 14. 97 ± 2. 23),respectively. There were 42 workers( 13. 73%) who had self-detected the occupational stress resulted from effort-reward imbalance; 62 workers( 20. 26%) were at high-risk of occupational stress. Compared with the industrial radiation workers,the scores of external effort and detection rate of occupational stress of hospital radiation workers were higher( P < 0. 05),while the high risk detection rate of occupational stress was lower( P < 0. 05). Compared with the female radiation workers, male workers had higher scores of external effort, effort / reward ratio and the detection rate of occupational stress( P < 0. 05) and lower scores of the reward score( P < 0. 05). The scores of external effort of radiation workers with junior college educational level or above were higher than those with senior high school educational level or below( P < 0. 05). CONCLUSION: The occupational stress level of radiation exposed workers has multiple influencing factors.It is recommended to strengthen the social support to improve their social and working environment,in order to reduce their occupational stress level.

The application of problem-based learning in clinical probation of gynecology and obstetrics / 中华医学教育探索杂志

ObjectiveTo investigate the teaching effect of problem-based learning(PBL) in clinical probation of gynecology and obstetrics.Methods48 students who majored in obstetrics and took internship in Xiamen Maternity and Child Care Hospital were selected as study subjects and were randomly assigned to control group and observation group.Traditional teaching pattern and PBL were performed in the above-mentioned groups respectively.The score of final test on maternity nursing and self-evaluation on capacity advancement were compared between two groups.ResultsThe score of observation group were significantly higher than control group (P＜0.05); Similarly,the self-evaluation of observation group after internship was also elevated with significance (P＜0.05) when being compared with control group.ConclusionEvidence showed that PBL was capable of improving the knowledge of maternity nursing,and it was also been proved effective in fostering the ability of self-learning,communication,and solving problem.Therefore,the PBL was appropriate to be promoted in the internship of nursing education.

Short-term central nervous system symptoms and changes in blood indicators after benzene poisoning in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the central nervous system symptoms and alterations in the blood indicators in rats within a short term after benzene poisoning.</p><p><b>METHOD</b>Twenty-four female SD rats were randomized into 4 equal groups to receive intraperitoneal injection of low-, medium- or high-dose benzene (39.05, 78.11, and 234.33 mg/kg, respectively) or peanut oil. Blood samples were taken from the rats via the femoral artery 24 h after the injections for routine blood test and liver and kidney function test.</p><p><b>RESULTS</b>Intraperitoneal injection of benzene at a high dose, but not at a low or medium dose, caused obvious symptoms in the central nervous system. Benzene either at a low or medium dose did not produce obvious changes in routine blood test or liver and kidney function test as compared with the control group, but a high dose resulted in significant changes in WBC, PLT, ALT and AST (P<0.05). Abnormalities in the renal function were found in none of the groups (P>0.05).</p><p><b>CONCLUSION</b>Exposure to high-dose benzene can result in abnormalities in the central nervous system, routine blood indicators and liver function, but does not obviously affect the kidney function in rats.</p>

The effect and mechanism of arsenic trioxide on hepatocellular carcinoma / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effect and mechanism of arsenic trioxide on hepatoma cell line BEL-7402 and observe the effect and best administration method of arsenic trioxide on hepatocellular carcinoma patients who were not suitable for operation.</p><p><b>METHODS</b>The cell activity and morphologic changes were studied after being treated with arsenic trioxide in different concentrations. The apoptosis was detected by flow cytometry assay and DNA fragmentation assay. The caspase-3 level of mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR) and fluoro-spectrophotometer. The growth inhibition of implant tumor was observed in nude mice treated with arsenic trioxide in different concentrations. Arsenic trioxide was used in hepatocellular carcinoma patients by intravenous dropping and continuous regional infusion through hepatic artery.</p><p><b>RESULTS</b>The effect of arsenic trioxide on hepatoma cell lines was dependent on the time and concentration obviously. The decrease in cell number was preceded by morphological changes in the treated BEL-7402 cells that were characteristic of apoptosis, including membrane blebbing, shrunken cytoplasm, nuclear condensation and loss of adhesion. Flow cytometry assay showed an arrestment at G(2)/M phase and sub-G(1) cell peak. DNA fragmentation assay showed a marked DNA ladder. The mRNA level of caspase-3 was no change in RT-PCR whereas the protein of caspase-3 was increased after added As(2)O(3) 1 - 36 h. Caspase-3 activity began to increase after 2 h and reached a maximal level after 12 h in a linear fashion. Then, the level of caspase-3 was decreased, but still in a high level. The growth inhibition of implant tumors was obviously in nude mice. The intravenous usage of arsenic trioxide could improve the quality of life with low toxicity in hepatocellular carcinoma patients not suitable for operation. The tumor size decreased in 30 patients and AFP value decreased in 19 patients by continuous regional infusion through hepatic artery.</p><p><b>CONCLUSIONS</b>Arsenic trioxide can obviously inhibit the growth of hepatoma cell line BEL-7402 through inducing hepatoma cell apoptosis. The activation and increase of Caspase-3 is the possible mechanism of apoptosis, and the acting point is in pro-enzyme level. The best result of arsenic trioxide on non-operative patients should be gotten in continuous infusion through hepatic artery.</p>

Expression of annexin II in human esophageal squamous cell carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the expression of annexin II in human esophageal squamous cell carcinoma (ESCC) and its relation with clinicopathological data.</p><p><b>METHODS</b>The expression of annexin II mRNA and protein in paired cancer tissues and their adjacent quasi-normal tissues were detected by RT-PCR, immunohistochemical method and densitometric scanning. The relation between annexin II expression and the status of tumor differentiation was analyzed.</p><p><b>RESULTS</b>The expression of annexin II was significantly lower in the tumor tissue than that in its paired normal counterpart both in mRNA and protein level (P < 0.05, P < 0.01). The protein expression of annexin II was significantly lower in moderately and poorly differentiated tumors than those in well differentiated ones (P < 0.05).</p><p><b>CONCLUSION</b>Down-regulation of annexin II in esophageal carcinogenesis may play an important role in squamous cell differentiation.</p>

Key activities involved in conduct of clinical trials / 中国临床药理学与治疗学

Key trial activities include: development of the trial protocol;development of standard operating procedures;development of support systems and tools;generation and approval of trial information documents;selection of trial sites and the selection of properly qualified,trained,and experienced investigators and study personnel;ethics committee review and approval of the protocol;review and approval by applicable regulatory authorities;enrollment of subjects into the study: recruitment,eligibility,and informed consent;the investigational product(s): quality,handling,and accounting;trial data acquisition: conducting the trial;trial data acquisition: conducting the trial; safety management and reporting;monitoring the trial;managing trial data;quality assurance of the trial performance and data;reporting the trial.