The sciatic nerves of rabbit were frozen with different temperatures(-20℃,-60℃, -- 100℃, -140℃ and 180℃).The morphology and function of the frozen nerves were examined with light microscopy (HE stain and histochemical thiocholism method), electron microscopy, and short latency sematesthelic evoked potentials(SSEP), sensory conduction velocity(SCV), electromyo-gram(EMG) at various time intervals after freezing. It was showed that there were no changes in morphology and function of nerves after being frozen at -20C. The nerve fibers showed signs of frozen degeneration and lost their conduction function at -60℃. However, the nerves could recover in this group. About one half of the nerve fibres frozen with -100℃ showed Wallerian degeneration, and the time of repair was delayed. But still the regeneration of nerves was complete. Necrosis of nerve fibers occurred immediately after freezing with -140℃ and-180℃. There were destruction of the basement membrane and proliferation of collagen fibers. The results explained the mechanism of cryoanalgesia clinically. We believe that the temperatures lower than -140℃ are optimal for cryoanalgesia.

Objective To make a comparison of curative effect of 1 and 2 ureters anastomosis in modified sigma operation. Methods Modified sigma operation was used after radical cystectomy in 14 cases of bladder transitional cell carcinoma and 1 case of adenocarcinoma of the bladder.We used a folded suture of 25 cm from the sigmoid colon to make the U-shaped urinary reservoirs to anastomose with the ureters in study group.Among study group,1 ureter was anastomosed with urinary reservoir in 5 cases.In the other 10 cases,1.5-2 cm of the terminal parts of 2 ureters were sutured tI am not sure what the authors mean by big diamogether and then anastomosed with the urinary reservoir.Results 15 cases obtained good voiding control and no obvious water-electrolyte disturbance occurred.All the patients were cured and discharged within 15 to 22 days.Thirteen cases were followed-up in 8 to 24 month time period.Anastonmtic stenosis and moderate-severe hydronephrosis occurred in 4 cases with 1 ureter anastomosis.No hydronephrosis occurred in the 9 cases with 2 ureters anastomosis.Conclusions Modified sigma operation has the advantages of less injury and fewer complications.The patients can obtain self-control urination by anal sphincter without urine bags or intermittent catheterization,so the life quality of the patients is improved.Modified sigma operation with 2 ureters anastomosis has big diameter and there was a lower incidence of serious complications such as anastomotic stenosis.

Objective To analyze the present situation of the dental instrument cleaning and disinfection in Hainan province and to explore the management mode of dental instrument cleaning and disinfection which is suitable for the provincial situation .Meth-ods By adopting the stratified random sampling method according to the hospital grades ,24 hospitals in Hainan province were per-formed the questionnaire survey on the cleaning mode of oral instruments ,layout of cleaning and disinfection room ,cleaning method and facilities ,protection measures and training of cleaning staff .Results 14 hospitals (58 .33% ) had the sterilization and supply center for conducting the centralized processing on the dental instruments .The tertiary hospitals and the second-grade hospitals had the independent cleaning and disinfection rooms with the rational layout and professional cleaning staff ;the safeguard facilities had the application in place ,the training of the related cleaning and disinfection work and the cleaning process conformed the require-ment of the standards .Among 10 first-grade and below hospitals ,only 1 hospital(10 .00% ) had the rational layout of cleaning and disinfection rooms ;3 hospitals(30 .00% ) had the professional cleaning staff ;the related training of the cleaning staff was not basi-cally carried out and the safeguard was not in place ,most of the cleaning and disinfection instruments and the cleaning process were not in accordance with the requirements .The qualification rates of instruments cleaning and disinfection in different grades of hospi-tals by the ATP bioluminescence assay were 100 .00% ,90 .00% and 80 .00% .Conclusion The existing problems are general and prominent in the hospitals of the first-grade and below .It is suggested that the regionalized disinfection and supply management mode is implemented for maximally realizing the optimized resource configuration in the disinfection and supply center .

Objective To study the ingenious method to suture laparoscopic puncture holes.Methods A curved needle and a hook-like needle were used in 650 patients during biliary tract surgery.Results The curved needle was used in 200 patients and the hook-like needle was used in 450 patients.All patients had good wound healing except for one patient who developed puncture hole seroma under the xiphoid.The patient was treated with drainage and improved rapidly.No other complications such as puncture hole hemorrhage,infection and puncture hole hernia occurred.Conclusion Suturing using a curved needle and a hook-like needle was easy and effective,and avoided complications.

Cholecystolithiasis with choledocholithiasis (CCL) is a common disease.The removal of common bile stone is a challenge for the surgery.This paper discussed the clinical application of three stone removal techniques including direct stone removal,irrigation and stone extraction by basket under cholangioscopy in order to take the stones effectively and safely,shorten the procedure time,avoid the injuries of common bile duct wall caused by the repetition of a single method such as biliary endoscopic stone extraction,reduce the difficulty of taking stone and enhance recovery of patients.