Objective To determine the median effective concentration (EC50) of remifentanil inhibiting responses to tracheal extubation in patients of Uygur nationality.Methods The patients of Uygur nationality,aged 18-60 yr,of ASA physical status Ⅰ or [Ⅱ,scheduled for elective surgery,were enrolled in this study.After the end of surgery,remifentanil was given by target-controlled infusion until tracheal extubation.The initial target plasma concentration (Cp) of remifentanil was 2.0 ng/ml.The response was defined as positive when MAP and/or HR increased by ＞ 15％ of the level at the end of operation and the duration ＞ 15 s during extubation.Each time the target Cp increased/decreased if the cardiovascular response was positive or negative.The ratio between the two successive concentrations was 1.1.The EC50 and 95 ％ confidence interval of remifentanil blunting responses to extubation was calculated by Probit method.Results Twenty-eight patients completed the study.The EC50 and 95 ％ confidence interval of remifentanil required for inhibiting the responses to extubation was 1.75 ng/ml and 1.45-2.01 ng/ml.Conclusion The EC50 of remifentanil inhibiting the responses to tracheal extubation is 1.75 ng/ ml in patients of Uygur nationality.

AIM To determine the effect of L-arginin e on cerebral blood perfusion following subarachnoid hemorrhage(SAH) in rats. METHODS Endovascular perforating SAH models were replicated in Wista r rats, and animals were divided into sham-operated group, SAH group and SAH+ L-arginine group. Dynamic changes of regional cerebral blood flow (rCBF) with in 24 hours were measured and serum nitric oxide(NO, NO - 2/NO - 3)levels at different time points within 24 hours were detected. Mean arterial blood pre ssure and blood gas were monitored during the experiment. RESULTS No obvious change in physiological parameters in the three groups was observed . rCBF and serum nitric oxide level at every time point after operation in SAH g roup were lower than those in sham-operated group. Pathological alterations abo ve in SAH+L-arginine group were less obvious than those in SAH group. CONCLUSION L-arginine, by antagonizing the decrease of nitric oxi de, exerts protective effect on secondary cerebral ischemia following SAH.

OBJECTIVETo evaluate the value of arthroscopy for the diagnosis and treatment of hip joint disease.

METHODSArthroscopy was performed in 54 patients (68 hips) from July 1998 to September 2001. Of the 54 patients, 36 were male and 18 female, aged from 17 to 64 years. The disease was located on the left side in 18 patients, the right side in 22, and both sides in 14. In this group, osteoarthritis was noted in 21 patients, avascular necrosis of the femoral head in 16, infection of the hip joint in 3, chondrosarcoma in 2, synovial-chondromatosis in 7, acetabular labral tears in 2, and spondylitis in 3. The procedures of arthroscopy consisted of removal of loose bodies, debridement, and biopsy.

RESULTSThe operation made accurate diagnosis possible for chondrosarcoma, acetabular labral tears, and infection of the hip joint. After debridement of the hip joint for avascular necrosis of the femoral head, osteoarthritis and spondylitis, most patients in this group were free from pain, function and range of the motion were restored and the pathological process was delayed. The Harris hip scores increased by 27 on average.

CONCLUSIONArthroscopy plays an important role in accurate diagnosis and treatment of hip joint.

Adolescent ; Adult ; Arthroscopy ; Chondromatosis, Synovial ; diagnosis ; surgery ; Female ; Femur Head Necrosis ; diagnosis ; surgery ; Hip Joint ; Humans ; Joint Diseases ; diagnosis ; surgery ; Male ; Middle Aged ; Osteoarthritis, Hip ; diagnosis ; surgery ; Retrospective Studies ; Spondylitis, Ankylosing ; diagnosis ; surgery