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OBJECTIVE: To evaluate the genetic damage induced by occupational chromate exposure, and to analyze the association between human 8-oxoguanine-DNA N-glycosylase 1(hOGG1) polymorphisms and genetic damage in population with chromate exposure. METHODS: A total of 136 chromate exposed workers were recruited as exposure group by judgmental sampling method, and 156 workers without chromate and other occupational hazard factors exposure were recruited as control group. The whole blood chromium(WB-Cr) level was measured by inductively coupled plasma mass spectrometry. Urinary 8-hydroxy-2′-deoxyguanosine(8-OHdG) was determined by enzyme-linked immunosorbent assay. Four single nucleotide polymorphisms of hOGG1 gene were genotyped by the matrix assisted laser desorption ionization/time of flight mass spectrometry. RESULTS: The WB-Cr level was higher in the exposure group than that in the control group(meclian: 3.41 vs 0.90 μg/L, P<0.01). The urinary 8-OHdG level was higher in the exposure group compared with that in the control group(meclian: 6.02 vs 4.72 μg/g·creatinine, P<0.01). In study subjects(exposure group and control group), after adjusting the potential influencing factors such as age, body mass index(BMI), gender, smoking and drinking, chromate exposure might be a risk factor for increasing urinary 8-OHdG level(P<0.05), and the recessive models of rs293796 and rs13096551 were observed as risk factors of increasing urinary 8-OHdG level(P<0.05). In chromate exposure group, the additive and recessive models of rs293796 and the recessive model of rs13096551 were observed as risk factors of increasing urinary 8-OHdG level(P<0.05), while the dominant model of rs3219008 was protective factor of increasing urinary 8-OHdG level(P<0.05), after adjusting the potential influencing factors such as age, BMI, gender, smoking, drinking. However, after multiple Bonferroni correction tests, only the recessive model of rs293796 was the risk factor of increasing urinary 8-OHdG level in the exposed group(P<0.01). There was significant interaction between chromate exposure and rs293796 on urinary 8-OHdG(P<0.01). CONCLUSION: The rs13096551 and rs293796 of hOGG1 were associated with the alteration of urinary 8-OHdG level induced by chromate. There was interaction between rs294796 of hOGG1 and chromate exposure on urinary 8-OHdG level.
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Objective To observe spinal cord neurotoxicity injury induced by mixture of bupiv-acaine-lidocaine compared with mixture of ropivacaine-lidocaine.Methods Forty-eight SD rats,weig-hing 250-300 g,were randomly allocated into 6 groups (n =8):NS group (group N),1.065% bupi-vacaine group (group B),1.5% ropivacaine group (group R),5% lidocaine group (group L),mix-ture group of 5% lidocaine and 1.065% bupivacaine (group LB)or mixture group of 5% lidocaine and 1.5% ropivacaine (group LR).The rats were given intrathecal cathetering after anesthesia.Tail-flick test (TFL)and the mechanical withdrawal threshold (MWT)of rats in each group were meas-ured 1 d before operation (the baseline values)and 1 d,2 d,3 d and 4 d after intrathecal administra-tion.The movement of rat double hind legs were observed at 10 min,30 min,1 h,2 h,3 h and 4 h and 1 d,2 d,3 d and 4 d after intrathecal administration,and the changes of recovery time of lower limbs were recorded.The rats were sacrificed 4 days postoperatively followed by observation on the indexes mentioned above,and spinal cord and cauda equine were taken for staining.Then the patho-logical changes of spinal cord were observed under light and electron microscope,and caudal nerve was rated for pathological injury.Results TFLs of group LR were obviously longer than those of group N,L,B,R,LB 1-4 d after intrathecal administration (P <0.05);Compared with the group N,there was no statistical difference of TFL in the group L,B,R,LB;there was no statistically sig-nificant difference of rat MWT in comparison among the six groups at each time point.There was no statistically significant difference among six groups in recovery time of movement after intrathecal ad-ministration;and the pathological injury scores were obviously higher in group LR than that of group N,L,B,R,LB (P <0.05),respectively.Compared with the group N,there was no statistical difference of the pathological injury scores in the group L,B,R and LB,respectively.Under light microscopy observa-tion:the structure of spinal cord was normal in group N,B and R.In group L and LB,there was focal ede-ma of neurofibers.In group LR,there was edema of neurofibers or demyelination,accompanied with white mass edema in posterior horn of spinal cord.Under electron microscope,only slight edema of medullated fi-bers and unmyelinated nerve fiber was seen in group B and group R;part of the medullated fibers appeared sparse focal lamellar structure in group L and group LB;swelling and degeneration of neuraxon,separation of neuraxon from myelin sheath and disappearance of unmyelinated nerve fiber were seen in group LR. Conclusion The mixture of 5% lidocaine with 1.5% ropivacaine is more neurotoxic to spinal cord than the single administration of lidocaine or ropivacaine,moreover it is not obviously changed compared with the mixture of lidocaine with equipotent bupivacaine.
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Objective To investigate the effect of fascia iliaca compartment nerve block ( FICB) to early analgesia and emergence agitation for children after the operation of femur fractures, and compare with fentanyl.Methods Totally 36 cases of children, which scheduled for the one-sided femur fractures surgery were selected after the approval from the Institutional Review Board of the hospital.They were randomly di-vided into two groups:FI group ( FICB group) and FE group ( Intravenous fentanyl group) .Patients in both groups were received ultrasound guided FICB immediately after the induction of general anesthesia, 1 ml/kg ropivacaine ( Naropin) was given in the FI group and 1 ml/kg saline in the FE group, sevoflurane was used for the anesthesia maintenance and 1 μg/kg intravenous fentanyl in FE group, instead of the same volume saline in FI group at 10 min before the surgery finished, and patients were sent to postanesthesia care unit ( PACU) after extubation.Keep a record of the duration of the operation and extubation, the pain scores and the Pediatric Agitation and Emergence Delirium ( PAED) scores were recorded at just arrived at PACU ( T0 ) , 10 min ( T1 ) , and 20 min ( T3 ) after PACU, also included the duration in PACU and the postopera-tively side effects.Results At the time of T0 and T1 , the pain scores in FI group was significantly lower than the FE( P 0.05), but it was still lower in FI group from the age of 8 to 14( P <0.05);The PAED scores at the three time points were always lower in FI group when it was compared with FE group;the same trend occurred for the duration of extubation and PACU( P <0.05).Conclusions FICB can effectively reduce emergence agitation and the pain scores for the children undergoing the surgery of femur fractures during the early time after the operation, which is better than the intravenous fentanyl.
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Objective To investigate the effect of intrathecal nerve growth factor (NGF) on lidocaineinduced neurotoxicity to the spinal cord in rats.Methods Thirty healthy male Sprague-Dawley rats,aged 8-10 weeks,weighing 250-300 g,were randomly divided into 5 groups (n =6 each) using a random number table:control group (group C),sham operation group (group S),lidocaine-induced neurotoxicity group (group L),normal saline group (group NS) and NGF group (group NGF).A catheter was inserted at L4.5 interspace into the epidural space in S,L,NS,and NGF groups.One day after surgery,20％ lidocaine 20 μl was injected intrathecally.At 24 h after lidocaine injection,normal saline 20 μl and NGF 10 μg (20 μd) were injected intrathecally in NS and NGF groups,respectively,once a day for 7 consecutive days.The tail flick latency (TFL) to a thermal nociceptive stimulus was measured on 1,3,5 and 7 days after lidocaine injection.The animals were sacrificed after the behavioral test was completed at 7 days after lidocaine injection,and the lumbar segments of the spinal cord were removed to detect the neuronal apoptosis (using flow cytometry) and caspase-3 mRNA expression (by RT-PCR).Results Compared with group C,the TFL was significantly prolonged at 1-7 days after lidocaine injection in L and NS groups and at 1-5 days after lidocaine injection in group NGF,the apoptosis rate was increased in L,NS and NGF groups,and caspase-3 mRNA expression was up-regulated in L and NS groups,and no significant change was found in the parameters mentioned above in group S.Compared with group L,the TFL was significantly shortened at 5 and 7 days after lidocaine injection,the apoptosis rate was decreased,and caspase3 mRNA expression was down-regulated in NGF group,and no significant change was found in the parameters mentioned above in group NS.Conclusion Intrathecal NGF can reduce lidocaine-induced neurotoxicity to the spinal cord in rats and inhibition of caspase-3 mRNA expression is involved in the mechanism.
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Objective To evaluate the effects of hyperbaric oxygen post-conditioning on the expression of P2X4 receptors in the spinal dorsal horn and hippocampus of rats with neuropathic pain (NP).Methods Seventytwo male Sprague-Dawley rats,aged 8-10 weeks,weighing 300-350 g,were randomly divided into 3 groups (n =24 each) using a random number table:sham operation group (group S),NP group and hyperbaric oxygen postconditioning group (group H).NP was induced by chronic constrictive injury.The rats in group H underwent hyperbaric oxygen treatment once a day for 7 consecutive days starting from 1 day after NP was successfully induced.After the rats were placed in the hyperbaric oxygen chamber,the pressure was increased at a rate of 10 kPa/min until the hyperbaric oxygen was at 2.0 atmosphere absolute,and maintained at this level for 60 min,and then the pressure was decreased at a rate of 10 kPa/min until the normal pressure was reached.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 1 day before NP was induced and 1,3,7 and 14 days after NP was induced.After the end of measurement,6 rats were randomly chosen from each group and then sacrificed and the L4-6 segments of the spinal cord and hippocampal tissues were removed for determination of the expression of P2X4 receptors (by immunohistochemistry).Results Compared with group S,the MWT was significantly decreased,TWL was shortened,and P2X4 receptor expression in the spinal dorsal horn and hippocampus was up-regulated in NP and H groups.Compared with group NP,the MWT was significantly increased and TWL was prolonged,and P2X4 receptor expression in the spinal dorsal horn and hippocampus was down-regulated in group H.Conclusion Hyperbaric oxygen post-conditioning mitigates NP by down-regulating the expression of P2X4 receptors in the spinal dorsal horn and hippocampus of rats.
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Objective To compare the preemptive analgesia effect of flurbiprofen axetil with tramadol in patients undergoing laparoscopic hysterectomy. Methods Ninety patients undergoing laparoscopic hysterectomy were divided randomly into group A (n=30), group B (n=30) and group C (n=30). The patients in group A were administrated 1mg/kg flurbiprofen axetil intravenously before tracheal intubation, and in group B 2mg/kg tramadol intravenously before tracheal intubation, while in group C 1mg/kg flurbiprofen axetil were administrated intravenously at the end of operation. The postoperative analgesic effects (1, 2, 4, 8, 12, 24 hours) were evaluated by VAS score and BCS score, while the times of pain-killer boosting and the side effects were recorded. Results VAS scores of group C were significantly higher than those of group A and B at all time points (P<0.05), except for 12 hours and 24 hours after the surgery, while BCS scores of group C Were lower than those of group A and B at the same time points (P<0.05).The side effects of group A and group C were significantly lower than those of group B (P<0.05). Conclusion Preemptive analgesia with flurbiprofen axetil and tramadol in patients undergoing laparoscopic hysterectomy is effective and convenient, while flurbiprofen axetil has less side effects.
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Objective To investigate the effect of hypoxia adaptation on cerebral ischemai hypoxic injury Methods Hypoxia pretreatment mouse was placed in a tightly closed 150 ml bottle with large opening Once the mouse developed dyspnea, it was taken out and placed in another tightly closed 150ml bottle filled with fresh air When the mouse was short of breath it was again taken out This process was repeated 4 times Ischemia hypoxia model the left common carotid artery was ligated under ether anethesia and 1h later the mouse was placed in a hypoxia chamber in which the oxygen concentration was maintained at 8% Twenty four Kunmin mice weighting 18 25g were divided into six groups of four animals each:(1) control group; (2) hypoxia pretreatment group; (3) ischemia hypoxia group I (group I H1): the mice stayed in hypoxia chamber for 1 h; (4) ischemia hypoxia group 2 (group I H2): the mice stayed in hypoxia chamber for 2h; (5) hypoxia pretreatment +I H1; (6) Hypoxia pretreatment +I H2 The animals were sacrificed immediately at the end of the experiment Neural apoptosis was identified by terminal deoxynucleotidyl transferase mediated dUPT biotin nick end labelling (TUNEL).Results Apoptosis cells could be seen scattered in the cerebral cortex in hypoxia adaptation group and group I H1 No apoptosis cells were found in control group and group I H2 But hypoxia adaptation increased the number of apoptosis cells in severe hypoxia ischemia group (group I H2) Conclusions Hypoxia adaptation protects brain against hypoxia ischemia injury Hypoxia adaptation induces apoptosis Hypoxia adaptation can have neurons end up in apoptosis instead of nacrosis during cerebral ischemia hypoxia
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Objective To investigate the protective effects of transection of the cervical sympathetic trunk (TCST) on the gastric mucosal lesions in rats fastened to a board and immersed vertically in water, up to the level of xiphoid with the animals' heads up water for 6 hours. Methods Thirty male SD rats weighing 200-250 g were randomly divided into 3 groups ( n = 10 each): group A sham operation; group B sham operation + water immersion and group C TCST + water immersion. The animals were anesthetized with intraperitoneal 2.5% pentobarbital 40 mg?kg-1. Cervical sympathetic trunk was exposed at right common carotid artery bifurcation and cut. The gastric mucosal blood flow (GMBF) was measured with Doppler blood flow monitor after 6 h water immersion. Blood samples were taken from abdominal aorta for determination of plasma concentration of ET-1 and serum concentration of NO. Gastric mucosal ulcer index was determined according to Guth criteria.Results There was gastric mucosa bleeding and erosion in group B and C and the degree of injury was severer in group B than in group C. Plasma concentration of ET-1 and serum concentration of NO were significantly higher in group B than in group C and A.Conclusion TCST has protective effect on gastric mucosal blood flow in rats under stress by reducing blood ET and NO concentrations.