[Establishment of a rat model of low calcium diet related hyperoxaluria].

OBJECTIVE: To establish a rat model of low calcium diet related hyperoxaluria and explore its features. METHODS: By means of randomized blocks design, totally 24 SD male rats were divided into low calcium diet group, medium calcium diet group, and high calcium diet group. Each group was sequentially fed on different calcium diets for 3 days. The urinary volume within 24 hours was recorded, the consistency of urinary oxalate by high-efficiency liquid chromatography, and the consistency of urine creatinine by automatic biochemical analyzer. The consistency was corrected to the output of urinary oxalate of rats in 24 hours, and the results were evaluated by repeated measurement of variance analysis and multivariate analysis of variance. RESULTS: The output of urinary oxalate of rats in 24 hours varied with time (F=7.893, P0.05). The output of urinary oxalate of rats in 24 hours varied with group division (F=3.565, P<0.05). The output of urinary oxalate in 24 hours in three groups on the third day was significantly higher than that on the first day (P<0.05). CONCLUSION: By controlling the calcium intake, we successfully established the model of low calcium diet related hyperoxaluria in rat.

[A modified rat model for infection-induced stone formation].

OBJECTIVE: To employ a newly modified rat model for infection-induced bladder stone formation. METHODS: 24 adult male Sprague Dawley rats were divided into 3 groups, model group (n=12), sham operation group (n=8) and control group (n=4). The surgical procedures were performed aseptically under anesthesia (25% Ultane 1.0 g/kg). The bladder in model group was exposed through a short lower midline abdominal incision, the puncture needle (G18) with guideline was inserted aseptically into bladder, a metal wire, which have been contaminated by the Proteus mirabilis, was put into the puncture canal, then implanted into the bladder lumen through the guideline. In the sham operated group the puncture needle (G18) with guideline was inserted into bladder without metal wire implanted into the bladder. There was no any operation in control group. The rats were sacrificed by excessive anesthesia at 21 days post challenge. The bladder were removed aseptically and inspected for evidence of urolithiasis. RESULTS: On Day 2 after surgery, two rats died in model group, no rats died in other groups. Twenty-one days after surgery, all of rats in model group developed various-sized bladder stones. There was no stone formation in sham operation group and control group. All stones were verified by infrared spectroscopy and optical crystallography. These stone were struvite stone. CONCLUSION: This model has a less trauma, faster recovery and excellent stone formation so that it may be used for the study of infection stone.

Shock wave lithotripsy for uric acid stones.

OBJECTIVE: To report our experience of extracorporeal shock wave lithotripsy (SWL) for patients with uric acid stones. METHODS: From December 1987 to December 2003, a total of 443 patients with uric acid stones in the kidney or ureter accepted SWL using ultrasound-guided lithotripters together with alkali therapy. Among them, 168 patients with an average stone burden of 9.1 mm were treated using an EDAP LT-01 piezoelectric lithotripter. The other patients, with an average stone burden of 9.6 mm, were treated using a Dornier Compact S electromagnetic lithotripter. RESULTS: The average duration of treatment using the EDAP LT-01 device was 52.1 minutes with a pulse frequency of 1.25-2.5 shocks per second at 100% power. The average treatment parameters on the Dornier Compact S device were 3,196 shocks at 14.8 kV. For the EDAP LT-01, the 3-month stone-free rate was 86.4%, with a retreatment rate of 24.2%. For the Dornier Compact S, the 3-month stone-free rate was 90.3%, with a retreatment rate of 29.0%. Auxiliary therapy with the push-back technique was needed in 0.45% of patients with upper ureteral stones that could not be localized using ultrasound. The treatment results were best for stones smaller than 20 mm. No anaesthesia was required for any patient. CONCLUSION: SWL with ultrasound localization for uric acid stones is safe and effective. The combination of SWL with urine alkalization may further improve the stone-free rate.

Shockwave lithotripsy: instrumentation and status in China.

PURPOSE: To introduce the physical background and technical characteristics of lithotripters made in China and to compare the efficacy of shockwave lithotripsy (SWL) for distal-ureteral stones between Chinese and Western lithotripters in consecutive use in our stone center. PATIENTS AND METHODS: From December 1987 to December 2003, we used a series of four lithotripters to treat 1802 patients with distal-ureteral stones: the piezoelectric EDAP LT-01 with ultrasound B-mode scanning for localization (N = 179); the electrohydraulic JDPN-IV lithotripter using fluoroscopy, which is made in China (N = 294), the electromagnetic Dornier Compact S with fluoroscopy/ultrasound dual localization (N = 1105), and the Huikang MZ-SWL-V, which is an electromagnetic- and electrohydraulic-compatible machine with dual localization that is made in China (N = 224). The physical background and technical characteristics of Chinese lithotripters are different from those of Western machines, but the treatment strategies were identical in all series. RESULTS: In the EDAP LT-01 series, the retreatment rate was 35.2%, and the auxiliary procedure rate was 6.7%, bring the efficiency quotient (EQ) to 69%. In the JDPN-IV series, the retreatment rate was 27.6%, the auxiliary procedure rate 1.0%, and the EQ 74%. In the Dornier Compact S series, the retreatment rate was 12.9%, and auxiliary procedures were performed in 10.9%, for an EQ of 81%. In the Huikang MZ-SWL-V series, the retreatment rate was 20.1%, the auxiliary procedure rate was 4.9%, and the EQ was 80%. CONCLUSION: The fragmentation results of Chinese electrohydraulic and electromagnetic lithotripters are superior to those of the EDAP LT-01. Chinese lithotripters are inferior to the Dornier Compact S in the efficacy of stone fragmentation, but Chinese machines cause less pain than this lithotripter.

[Living animal models of the medical shock wave].

This article reviews the methods, notes and evaluation of the living animal models of the medical shock wave, including directly shocked animal models, surgical implantation of stones into animal kidney models, implantation of tumor cells into animal models and animal bone models. The living animal models play an important role in studying the medical shock wave.

[Clinical investigation of the treatment of children urethral calculi with pneumatic lithotripsy under ureteroscopy].

OBJECTIVE: To evaluate the therapeutic effects of pneumatic lithotripsy on children urethral calculi. METHODS: Twenty-two cases of the male children with urethral calculi were treated with pneumatic lithotripsy under ureteroscopy. RESULTS: All the patients were treated successfully in a single procedure. The time of lithotripsy was (5.5 +/- 2.2) minutes, and no serious complication such as obvious hematuria, infection and urethral stricture occurred. CONCLUSIONS: It is suggested that pneumatic lithotripsy under ureteroscopy is an effective and simple way for the treatment of urethral calculi in children.