The uptake and retention of ~3H-HPD in.human malignant cells(cell line MGC 80-3,SGC-7901,BEL-7402,Os-732,Detroit-6 and HeLa)and normal fibroblasts were studied by liquid scintillation counting method.The order of cell lines which took up ~3H-HPD after 30 min.incubation were fibroblasts,HeLa, BEL-7402,Detroit-6,SGC-7901,MGC 80-3 and Os-732 respectively according to the amount of ~3H-HPD in cells.Due to the variety in the amount of excretion, however,those cells which retained ~3H-HPD after 24 hours cultivation were Os-732, Detroit-6, BEL-7402,HeLa,SGC-7901,MGC 80-3 and fibroblasts respectively in respect to the ~3H-HPD level in cells.The uptake was reduced by raising extracel- lular pH and lowering temperature as well as adding higher concentration of serum. Our results showed that the ~3H-HPD content in malignant ceils was higher than those in normal ones and it was because that malignant cells retained ~3H-HPD longer other than took up more

Objective To evaluate the efficacy of continuous lumbar plexus block (CLPB) combined with a bolus dose added at night for postoperative analgesia in patients undergoing hip arthroplasty.Methods Sixty ASA Ⅰ or Ⅱ patients of both sexes,aged 51-75 yr,weighing 47-77 kg,with body height 150-180 cm,scheduled for hip arthroplasty,were randomized to receive either CLPB (group CLPB) or patient-controlled intravenous analgesia (PCIA) (PCIA group) for postoperative analgesia (n =30 each).Spinal anesthesia was performed at L3,4 interspace.Postoperative analgesia was performed at 30 min before the end of surgery.PCIA solution contained morphine 100 mg in 100 ml of normal saline.The PCA pump was set up with a 2 mg bolus dose and a 5 min lockout interval.CLPB solution contained 0.125 ％ ropivacaine hydrochloride 200 ml.CLPB pump was set up to deliver a 4 ml bolus dose with a 30-min lockout interval and background infusion at 8 ml/h after a loading dose of 0.125％ ropivacaine 30 ml.In addition the patients received 0.25％ ropivacaine 30 ml at 8 o' clock every night after surgery in group CLPB.VAS scores at rest and during activity were recorded at 6,12,18,24,30,36,42 and 48h after operation.The side effect such as nausea and vomiting,pruritus and urinary retention were recorded within 48 h after operation.The patient' s satisfaction was assessed.The maximal hip flexion and abduction ranges of motion were recorded at 12,24,36 and 48 h after operation.The times of sleep interruption resulted from pain during nighttime were also recorded.Results Compared with group PCIA,the VAS scores during activity,severity of nausea and vomiting,pruritus and urinary retention,and times of sleep interruption resulted from pain during nighttime were significantly decreased,and the overall satisfaction score and maximal hip flexion and abduction ranges of motion were increased in group CLPB (P ＜ 0.05).Conclusion CLPB combined with a bolus dose added at night can provide better efficacy for postoperative analgesia in patients undergoing hip arthroplasty than PCIA,with fewer complications.

Objective To evaluate the effects of age factors on the pharmacokinetics of ropivacaine during combined lumbar plexus-sciatic nerve block in patients.Methods Twenty patients of both sexes,aged ≥ 18 yr,weighing 50-75 kg,of American Society of Anesthesiology physical status Ⅰ or Ⅱ,scheduled for elective lower extremity surgery,were divided into 2 groups (n=10 each) according to age:young and middle-aged group (18-59 yr) and elderly group (≥ 60 yr).Combined lumbar plexus-sciatic never block was performed using an ultrasonic instrument and a nerve stimulator.Lumbar plexus block was performed with 0.5％ ropivacaine 30 ml.Sciatic never block was performed with 2％ lidocaine 10 ml plus 0.75％ ropivacaine 10 ml.Before administration and at 5,10,15,20,30,45,60,120,180 and 360 min after administration,blood samples were collected from the radial artery for determination of the blood concentration of ropivacaine by high-performance liquid chromatography.The area under the concentrationtime curve,maximum concentration (Cmax),time to C terminal elimination half-life and clearance were calculated.Results Compared with young and middle-aged group,the blood concentration of ropivacaine was significantly decreased at 5-45 min after administration,the Cmax was significantly decreased,terminal elimination half-life was significantly prolonged (P＜0.05),and no significant change was found in area under the concentration-time curve,the time to C and clearance in elderly group (P＞ 0.05).Conclusion Age factors can affect the pharmacokinetics of ropivacaine during combined lumbar plexus-sciatic nerve block,and both absorption and metabolism of ropivacaine are slower in elderly patients than in young and middle-aged patients.