[Effects of electroacupuncture pretreatment on long-term postoperative cognitive dysfunction and neuron-inflammation in aged rats].

OBJECTIVE: To observe the effects of electroacupuncture pretreatment on postoperative cognitive dysfunction (POCD), neuronal apoptosis and neuron-inflammation in aged rats. METHODS: Thirty-six male SD rats aged 20 months were randomly divided into sham operation group, model group and electroacupuncture (EA) group, with 12 rats in each group. The POCD rats model was prepared by internal fixation of left tibial fracture. Five days before modeling, EA stimulation (2 Hz/15 Hz, 1 mA, 30 min) was applied to "Zusanli" (ST36), "Hegu" (LI4) and "Neiguan" (PC6) on the unaffected side of rats in the EA group, once a day for consecutive 5 d. The learning and memory abilities of rats were evaluated by water maze test 31-35 days after operation. The apoptosis of hippocampal neurons was observed by Tunel/NeuN double staining. The expressions of high mobility group protein B1 (HMGB1) and phosphorylated (p)-nuclear factor (NF)-κB in microglia cells in hippocampal dentate gyrus were detected by immunofluorescence staining. The expression levels of interleukin (IL)-6 and IL-1ß in the hippocampus were detected by Western blot. RESULTS: Compared with the sham operation group, the escape latency was prolonged (P<0.05); the frequency of crossing the original platform, ratio of the swimming distance and the time in the target quadrant of the Morris water maze were significantly decreased (P<0.05); the apoptosis rate of hippocampal neurons was significantly increased (P<0.05); the expressions of HMGB1 and p-NF-κB in microglia cells in the dentate gyrus and the expression levels of IL-6 and IL-1ß in hippocampus were increased (P<0.05) in the model group. Compared with the model group, the results of the above indexes were all opposite (P<0.05) in the EA group. CONCLUSION: EA preconditioning can regulate hippocampal inflammatory response, alleviate neuronal apoptosis rate and long-term cognitive dysfunction in aged rats with POCD, the mechanisms may be related to the inhibition of microglia HMGB1/NF-κB pathway in hippocampal dentate gyrus.

Median Effective Concentration of Ropivacaine for Femoral Nerve Block Maintaining Motor Function During Knee Arthroscopy in Two Age Groups.

Background: Femoral nerve block combined with general anesthesia is commonly used for patients undergoing knee arthroscopy in ambulatory care centers. An ideal analgesic agent would selectively (differentially) block sensory fibers, with little or no effect on motor nerves. Ropivacaine is considered to cause less motor block than others. This study investigated the median effective concentration (EC50) of ropivacaine for differential femoral nerve block in adults either younger or older than 60 years. Methods: Patients with American Society of Anesthesiologists physical status I-III and scheduled for knee arthroscopy were categorized as 18- to 60-years-old (Group 1), or older than 60 years (Group 2). Surgeries were performed under general anesthesia combined with femoral nerve block via 22 mL ropivacaine. The EC50 of ropivacaine for differential femoral nerve block was determined using the up-and-down method and probit regression. The primary outcome was the EC50 (95% confidence interval [CI]) of the 2 groups. Data on the sensory block, analgesic effect, complications, and hemodynamics during surgery were also recorded. Results: The EC50 of 22 mL ropivacaine for differential femoral nerve block of Group 1 (0.124%, 95% CI 0.097-0.143%) was significantly higher than that of Group 2 (0.088%, 95% CI 0.076-0.103%). The sensory block and hemodynamic data of the 2 groups were comparable. None of the patients experienced neurological complications. Conclusion: The EC50 of ropivacaine administered for differential femoral nerve block during knee arthroscopy was lower in patients older than 60 years, relative to younger adults.

Effect of transcutaneous electrical acupoint stimulation on the EC50 of remifentanil suppressing responses to tracheal extubation in elderly patients.

Transcutaneous electrical acupoint stimulation (TEAS) is a emerging treatment which combines transcutaneous electrical nerve stimulation with traditional acupoint therapy. The present study was aimed to evaluate the effect of TEAS on the effective concentration (EC50) of remifentanil suppressing tracheal extubation response in elderly patients.Fifty-three patients undergoing spine surgery were randomly divided into 2 groups: control group (group C, n = 26) and transcutaneous electrical acupoint stimulation group (group TEAS, n = 27). The EC50 values for remifentanil TCI were determined using sequential method and probit analysis.The remifentanil EC50 of that suppressed responses to extubation during anesthetic emergence was 1.20 ng/mL in group TEAS, a value that was significantly lower than the 1.64 ng/mL needed by patients in group C.The TEAS can enhance the efficacy of remifentanil on suppressing responses to tracheal extubation in elderly patients, the EC50 of remifentanil can reduce approximately 27% compared with group C.

Effects of preconditioning of electro-acupuncture on postoperative cognitive dysfunction in elderly: A prospective, randomized, controlled trial.

Electro-acupuncture is a burgeoning treatment using the needle inserting into the body acupoints and the low-frequency pulse current being electrified by an electric acupuncture machine. This study was designed to evaluate the effects of preconditioning of electro-acupuncture on postoperative cognitive dysfunction in elderly.Ninety patients scheduled spine surgery were randomly assigned into 2 groups using a random number table: control group (group C) and electro-acupuncture group (group EA). In group EA, electro-acupuncture was applied on Baihui, Dazhui, and Zusanli acupoints 30 minutes before anesthesia. At 0 minute before treatment of electro-acupuncture, 1 hour after skin incision and surgery completed (T1-3), blood samples were taken for detection of interleukin (IL)-6, IL-10, and S100ß by enzyme-linked immunosorbent assay. The total dose of remifentanil and propofol during surgery were recorded. Mini-Mental State Examination was applied to evaluate the cognitive function of patients at 1 day before surgery and 7th and 30th day after surgery.The results showed that compared with group C, score of MMSE increased after surgery, the serum concentration of IL-6, IL-10, and S100ß decreased at 1 hour after skin incision, and surgery completed in group EA. Moreover, the total dose of remifentanil and propofol reduced during surgery in group EA.The present study suggests that preconditioning of electro-acupuncture could improve the postoperative cognitive function, and the reduction of inflammatory reaction and brain injury may be involved in the mechanism.

Effects of nimodipine on postoperative delirium in elderly under general anesthesia: A prospective, randomized, controlled clinical trial.

Nimodipine is a clinical commonly used calcium antagonistscan lowering the apoptosis rate of hippocampal neuron to reduce the incidence of postoperative cognitive dysfunction (POCD). This study was designed to evaluate the effects of nimodipine on postoperative delirium in elderly under general anesthesia.Sixty patients shceduced spine surgery under general anesthesia were randomly assigned into 2 groups using a random number table: control group (Group C) and nimodipine group (Group N). In Group N, nimodipine 7.5 µg/(kg × h) was injected continually 30 minutes before anesthesia induction, while the equal volume of normal saline was given in Group C. At 0 minute before injection, 0 minute after tracheal intubation, 1 hour after skin incision and surgery completed (T1-4), blood samples were taken from the radial artery and jugular bulb for blood gas analysis. Cerebral oxygen metabolism-related indicators were calculated at the same time. Concentration of S100ß and glial fibrillary acidic protein (GFAP) were tested by ELISA. The incidence of postoperative delirium within 7 days after surgery was recorded.Cerebral oxygen metabolism-related indicators fluctuationed in the normal range in 2 groups at different time points and the difference were not statistically significant. Compared with Group C, S100ß and GFAP decreased and incidence of postoperative delirium reduced at T3-4 in Group N, the difference was statistically significant (P<.05).The present study suggests that nimodipine can reduce the development of postoperative delirium in elderly patients under general anesthesia, the reduction of brain injury and improvement of cerebral oxygen metabolism may be involved in the mechanism.

Quantitative determination of allele frequency in pooled DNA by using sequencing method.

Quantitative determination of the allele frequency of single-nucleotide polymorphism (SNP) in pooled DNA samples is a promising approach to clarify the relationships between SNPs and diseases. Here, we present such a simple, accurate, and inexpensive method for quantitative determining the allele frequency in pooled DNA samples. Three steps of DNA pooling, PCR amplification and sequencing are involved in this assay. Although direct determination of the allele frequency from the two allele-specific fluorescence intensities is possible, correction for differential response of alleles is important. We explored the effect of differential response of alleles on test statistics and provide a solution to this problem based on heterozygous fluorescence intensities. We demonstrate the accuracy and reliability of this assay on pooled DNA samples with pre-determined allele frequencies from 7.1% to 53.9%. The accuracy of allele frequency measurements is high, with a correlation coefficient of r² = 0.997 between measured and known frequencies. We believe that by providing a means for SNP genotyping up to hundreds of samples simultaneously, inexpensively, and reproducibly, this method is a powerful strategy for detecting meaningful polymorphic differences in candidate gene association studies.