A Patient with Fragmentation of a Calcified Ureteric Stent Requiring Ureteroscopy and Laser Lithotripsy.

BACKGROUND Encrustation of the ureteral stent is a common complication that occurs after a prolonged indwelling duration. Other identified risk factors in the literature include urinary sepsis, chemotherapy, chronic renal failure, metabolic or congenital abnormalities, and nephrolithiasis. This report presents the case of a 39-year-old man with nephrolithiasis and fragmentation of a calcified right ureteric stent that required ureteroscopy and laser lithotripsy. CASE REPORT A 39-year-old man was initially admitted for ureteroscopy and laser lithotripsy after the diagnosis of bilateral urolithiasis. Ureteral stents were placed. One postoperative month later, the patient returned for follow-up and stent withdrawal. Follow-up computed tomography revealed a normal left kidney, intact bilateral ureteral stents, and residual right renal stones. However, an attempt to completely withdraw the stent failed and the patient had to undergo a secondary right ureteroscopy with laser lithotripsy. The fragmented proximal section of a calcified right ureteral stent with occluded lumen was found intraoperatively and sent for product analyses. After successful reintervention, the patient had a new right ureteral stent placed, which was successfully withdrawn during his next follow-up. CONCLUSIONS Ureteral stent encrustation may occur earlier than anticipated, possibly due to underlying patient risk factors. Complications, such as fragmentation of the ureteral stent, may occur during withdrawal. Physicians should be aware of any predictors for early ureteral stent encrustation to prevent unnecessary reintervention.

Preliminary Study on Solid-state Fermentation of Streptomyces Strain Men-myco-93-63 / 微生物学通报

The culture medium and cultural conditions of solid-state fermentation of Streptomyces Menmyco-93-63 were tested in this study. The suitable medium which contains rice, sorghum, millet bran, and rice hull with the proportion of 2:2:3:3 was developed for the spore production of Streptomyces Men-myco-93-63 using single substrate screening, mixture substrate screening and orthogonal experiments, and the sporulation was up to 2.52?109 CFU/g. And then, initial charge, initial ratio of water to solid, inoculating quantity, and culture temperature impact to sporulation of Streptomyces Men-myco-93-63 were tested. The favorite cultural conditions are developed as the following: the initial charge is 15 g in 500 mL Erlenmeyer flask; initial ratio of water to solid is 1.7:1.0 (V/W, rice hull excluding), inoculating quantity is 7 mL, culture temperature is 28℃.