Involvement of kainate receptors in the analgesic but not hypnotic effects induced by inhalation anesthetics.

In the present study, the role of kainate (KA) receptors in hypnosis and analgesia induced by emulsified inhalation anesthetics was investigated. A mouse model of hypnosis and analgesia was established by an intraperitoneal injection of emulsified enflurane, isoflurane or sevoflurane. We intracerebroventricularly (icv) or intrathecally (it) administered KA, a KA receptor agonist to mice. The effects of the KA on the sleep time were observed using a hypnosis test, and the tail-withdrawal latency was analyzed using the tail-withdrawal test. In the hypnosis test, KA (2.5, 5 or 10 ng; icv administered) treatment had no distinctive effects on the sleep time of mice treated with emulsified inhalation anesthetics. In the tail-withdrawal test, KA (0.2, 0.4 or 0.8 ng; it administered) treatment significantly and dose-dependently decreased the tail-withdrawal latency of mice treated with emulsified anesthetics. These results suggested that KA receptors may modulate the analgesic but not hypnotic effects induced by emulsified enflurane, isoflurane or sevoflurane.

The ED50 and ED95 of ketamine for prevention of postoperative hyperalgesia after remifentanil-based anaesthesia in patients undergoing laparoscopic cholecystectomy.

OBJECTIVE: Various research programmes have shown that intraoperative infusion of remifentanil has been associated with postoperative hyperalgesia. Previous studies have demonstrated that low-dose ketamine can inhibit central sensitisation and prevent opioid-induced hyperalgesia (OIH). However, the optimal ketamine dose to prevent OIH has not been determined. In the present study we aimed to determine the ED50 and ED95 of ketamine for prevention of postoperative hyperalgesia after remifentanil-based anaesthesia in patients undergoing laparoscopic cholecystectomy. METHODS: Fifty-four patients undergoing laparoscopic cholecystectomy were randomised into two groups: group C and group K. Group K was given ketamine before skin incision. An equal volume of normal saline was given to the patients in group C. Pain was assessed using visual analog scale (VAS) at 10 min after tracheal extubation. The ED50 and ED95 were determined by modified up-and-down method and the incidences of adverse effects were recorded. RESULTS: The incidences of adverse effects were similar in the two groups and the VAS score was significantly lower in group K than in group C. The ED50 and ED95 of ketamine for prevention of postoperative hyperalgesia were 0.24 mg/kg (95%CI, 0.20~0.30 mg/kg) and 0.33 mg/kg (95%CI, 0.28~0.62 mg/kg) respectively. CONCLUSIONS: The ED50 and ED95 of ketamine for prevention of postoperative hyperalgesia after remifentanil-based anaesthesia in patients undergoing laparoscopic cholecystectomy were 0.24 mg/kg and 0.33 mg/kg respectively.

[Levels of environmental endocrine disruptors in umbilical cord blood and maternal blood of low-birth-weight infants].

OBJECTIVE: To monitor the biological levels of environmental endocrine disruptors (EDs, phthalates and surfactants) in the umbilical cord blood and maternal blood of low-birth-weight infants. METHODS: All 30 umbilical cord blood samples and 21 maternal blood samples were collected from low-birth-weight infants. The concentration of four kinds of phthalates (di-2-ethylhexyl phthalate, DEHP; mono-2-ethylhexyl phthalate, MEHP; di-ethyl phthalate, DEP; di-n-butyl phthalate, DBP) and two kinds of surfactants (4-nonylphenol, 4-NP; octylphenol, OP) in these blood samples were measured by using reversed-phase high performance liquid chromatography. RESULTS: The mean birth weight and birth length of low-birth-weight infants were (2158.48 +/- 125.06) g and (45.36 +/- 2.52) cm, respectively. The concentrations of DEP, MEHP, DBP, DEHP, 4-NP and OP were 18.90, 11.87, 7.67, 8.84, 1.51 and 2. 86 mg/L in maternal blood, and the detective rates were 86.7%, 63.3%, 60.0%, 63.3%, 56.7% and 66.7%, respectively. In umbilical cord blood, the concentrations of those EDs were 11.92, 9.94, 5.71, 5.20, 1.12 and 1.19 mg/L; the detective rates were 86.7%, 63.3%, 60.0%, 63.3%, 56.7% and 66.7%. No matter in maternal blood or in umbilical cord blood, the contents and detective rates of phthalates were higher than the surfactants. The concentration of MEHP was higher than its primer, DEHP. The contents of the target EDs in umbilical cord blood were less than those in the matched maternal blood. The percentages were 47.82% -84.05%. CONCLUSION: People could be exposed to EDs from embryo period. And this should be paid attention by the related departments.