Objective To evaluate the effect of dexmedetomidine on lung injury induced by extremity ischemia-reperfusion.Methods Forty patients,aged 18-60 yr,with body mass index of 20-25 kg/m2,of ASA physical status Ⅰ or Ⅱ,with 1 h ≤ predicted duration of surgery ≤ 1.5 h,were randomly divided into 2 groups (n =20 each) using a random number table:control group (group C) and dexmedetomidine group (group D).In groupD,dexmedetomidine 1 (g/kg was infused intravenously for 10 min,followed by continuous infusion of dexmedetomidine at 0.5 μg· kg-1 · h-1 until the end of the surgery,while in group C the equal volume of normal saline was given instead.Immediately before induction of anesthesia (T1,baseline),at 60 min after tourniquet was inflated (T2) and at 30 min,2 h and 6 h after tourniquet release (T3-5),blood samples were collected from the radial artery for blood gas analysis and for measurement of the levels of plasma interleukin-6 (IL-6),IL-8,tumor necrosis factor-α (TNF-α),malondialdehyde (MDA) and superoxide dismutase (SOD),and arterial partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were recorded.Alveolar-arterial oxygen difference (A-aDO2) and respiratory index (RI) were calculated.Results Compared with group C,PaO2 was significantly increased at T5,and A-aDO2 and RI at T5,the levels of plasma IL-6 and IL-8 were decreased at T4,5 and the levels of plasma TNF-α,MDA and SOD were decreased at T3-5 in group D.Conclusion Dexmedetomidine can attenuate lung injury induced by extremity ischemia/reperfusion via inhibiting inflammatory responses and lipid peroxidation.

OBJECTIVETo investigating genetic effects of workers occupationally exposed to mercury (Hg).

METHODSThe peripheral lymphocytes from 20 workers exposed to mercury and 20 controls were measured with micronucleus test, comet assay, hrpt gene mutation test and TCR gene mutation test.

RESULTSThe mean micronuclei rate(MNR) and mean micronucleated cells rate(MCR) in 20 workers were (5.90 +/- 0.91) per thousand and (5.30 +/- 0.81) per thousand, respectively while MNR and MCR in controls were (1.50 +/- 0.47) per thousand and (1.30 +/- 0.31) per thousand respectively, The difference of MNR and MCR between workers and controls was very significant (P < 0.01). The mean tail length (MTL) of workers and controls were (3.16 +/- 0.31) and (0.99 +/- 0.07) microm, respectively. The mean tail moment (MTM) of workers and controls were 1.63 +/- 0.22 and 0.39 +/- 0.03, respectively, There was a significant difference in MTL and MTM between workers and controls(P < 0.01). When the average mutation frequencies (Mfs-hprt) of hprt and (Mfs-TCR) of TCR of workers were compared with those of controls, there were not significant difference (P > 0.05).

CONCLUSIONThe results of the investigation indicated that the adverse genetic effects in workers occupationally exposed to mercury could be detected.

Adult ; Case-Control Studies ; Chemical Industry ; Comet Assay ; Female ; Humans ; Male ; Mercury ; Micronucleus Tests ; Middle Aged ; Mutation Rate ; Occupational Exposure ; adverse effects ; Young Adult