Stable isotope fractionation of cadmium in the soil-rice-human continuum.

Consumption of rice (Oryza sativa) grain is a major pathway by which humans are exposed to Cd, especially in non-smoking Asian populations. Although the stable isotope signatures of Cd offer a potential tool for tracing its sources, little is known about the isotopic fractionation of Cd across the entire soil-rice-human continuum. Cadmium isotope ratios were determined in field soils, rice grain, and human urine collected from two Cd-contaminated regions in southern China. Additionally, Cd isotopic fractionation in rice plants was investigated using two transgenic plants differing in Cd uptake and accumulation. Analysis of isotope ratios revealed a preferential enrichment of the heavy Cd isotopes from soil to rice grain (δ114/110Cdgrain-soil = +0.40‰) and from grain to urine (δ114/110Cdurine-grain = +0.40‰) in both regions. The first increase was mainly caused by partitioning between the soil solid phase and the soil solution, with heavier Cd preferentially enriching in the soil solution. Within the rice plant, we identified multiple processes that alter the isotope ratio, but the net effect throughout the plant was comparatively small. Cd fractionation in humans is presumably due to the preferential enrichment of heavier Cd isotopes by metal transporters DMT1 and ZIP8 (responsible for the absorption of Cd into body from the foods). These findings provide important insights into the Cd isotopic fractionation through the soil-rice-human continuum and are helpful for tracing the sources of Cd.

Effects of intravenous lidocaine, dexmedetomidine and their combination on postoperative pain and bowel function recovery after abdominal hysterectomy.

BACKGROUND: Intravenous (IV) lidocaine and dexmedetomidine have been shown to decrease postoperative pain, reduce analgesic consumption and facilitate return of bowel function. We investigated whether lidocaine combined with dexmedetomidine infusion was superior in controlling pain and recovery of bowel function. METHODS: A total of 240 women undergoing elective abdominal hysterectomy were randomly assigned into four groups: group CON received normal saline infusion, group LIDO received lidocaine infusion (1.5 mg/kg loading, 1.5 mg/kg/h infusion), group DEX received dexmedetomidine infusion (0.5 µg/kg loading, 0.4 µg/kg/h infusion) and group LIDO+DEX received lidocaine (1.5 mg/kg loading, 1.5 mg/kg/h infusion) and dexmedetomidine infusions (0.5 µg/kg loading, 0.4 µg/kg/h infusion). The primary outcome was visual analog pain scale (VAS) scores at 1, 4, 8, 12, 24, and 48 hours after surgery. The secondary outcomes included time to first bowel sounds and flatus, postoperative fentanyl requirement and perioperative propofol and remifentanil consumption. RESULTS: The VAS scores were significantly lower in groups LIDO and DEX at 4, 8, and 12 hours compared to group CON after surgery (P<0.01). The VAS scores were also significantly lower in group LIDO+DEX at 1, 4, 8, 12, and 24 hours compared to other three groups after surgery (P<0.01). Time to first bowel sounds and flatus was significantly shorter in groups LIDO and LIDO+DEX than groups CON and DEX (P<0.01). Postoperative fentanyl requirement was significantly lower in group LIDO at 1 and 4 hours and in group DEX at 1, 4, 8 hours compared to group CON after surgery (P<0.01). Postoperative fentanyl requirement was also significantly lower in group LIDO+DEX at 1, 4, 8, 12, 24 and 48 hours compared to other three groups after surgery (P<0.01). Propofol and remifentanil consumption was significantly lower in groups LIDO, DEX and LIDO+DEX compared to group CON (P<0.01). CONCLUSIONS: Lidocaine combined with dexmedetomidine infusion significantly improved postoperative pain and enhanced recovery of bowel function undergoing abdominal hysterectomy.

[Application of argon-nitrogen mixed gas inductively coupled plasma in elements and isotopes analysis].

To improve the precision and accuracy of elements and isotopes analysis in traditional Ar-ICP, the addition of nitrogen in ICP has been widely used. The present review focused on the discussions of the basic physical and chemical properties of the Ar-N2 mixed gas inductively coupled plasma and the mechanisms of the special nature of Ar-N2 mixed gas plasma. The applications of Ar-N2 inductively coupled plasma in spectral analysis and mass spectrometry analysis in the past 40 years were summarized. The authors also give an overall outlook on the application of this technology.

Effects of Wy14643 on hepatic ischemia reperfusion injury in rats.

AIM: To investigate the effects and possible mechanisms of Wy14643 on hepatic ischemia-reperfusion (I/R) injury in rats. METHODS: Thirty male Sprague-Dawley rats weighing 220-280 g were randomly divided into five experimental groups: sham group (G1, n=6): a sham operation was performed (except for liver I/R); I/R-untreated group (G2, n=6): rats underwent liver ischemia for 90 min followed by reperfusion for 4 h; and I/R+Wy14643 groups (G3, G4, G5; n=6): after the same surgical procedure as in group 2, animals were pretreated with Wy14643 at the dose of 1, 5 and 10 mg/kg 1 h before ischemia, respectively. Hepatic ischemia-reperfusion (I/R) was induced by clamping blood supply to the left lateral and median lobes of the liver for 90 min, and atraumatic clamp was removed for 4 h reperfusion. Blood samples and liver tissues were obtained at the end of reperfusion to assess serum and hepatic tissue homogenate aminotransferase (ALT), aspartate aminotransferase (AST), myeloperoxidase (MPO), serum interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha), as well as activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA) in the hepatic tissue homogenate. RESULTS: Hepatic I/R induced a significant increase in the serum levels of ALT, AST, TNF-alpha, IL-1beta and MPO, as well as the levels of ALT, AST and MDA in the liver tissue homogenate, which were reduced by pretreatment with Wy14643 at the dose of 1, 5 and 10 mg/kg, respectively. The activity of SOD in the liver tissue homogenate was decreased after hepatic I/R, which was enhanced by Wy14643 pretreatment. In addition, serum and liver tissue homogenate ALT and AST in the Wy14643 10 mg/kg group were lower than in the Wy14643 1 mg/kg and 5 mg/kg groups, respectively. CONCLUSION: Wy14643 pretreatment exerts significant protection against hepatic I/R injury in rats. The protective effects are possibly associated with enhancement of anti-oxidant and inhibition inflammation response.