Vol. 171, No.4, Supplement, Monday, May 10, 2004 Kidney (MOCK) cells form calcium phosphate microliths at the basolateral side in vitro. We investigated the inhibitory effects of new generation bisphosphonates (alendronate and incadronate) on calcium phosphate microlith formation and on the expression of osteopontin, which is an important urinary stone matrix. METHODS: MOCK cells formed two types of colonies, dark colonies containing calcium phosphate microliths and clear colonies free from microliths in three-dimensional soft agar culture (Fig. 1, Fig. 2). We applied purified alendronate and incadronate at concentrations of w·", w·•, 10· 7 and 10· 5 M to MOCK cells cultured in three-dimensional soft agar and investigated the efficiency of colony formation and the dark colony ratio (number of dark colonies relative to the total number of colonies). RESULTS: The administration of w·• and 10· 7 M alendronate decreased the dark colony ratio compared with the controls value, whereas incadronate did not significantly alter the dark colony ratio compared with controls (Fig. 3). The expression of osteopontin in cultured cells was inhibited by the administration of 10· 7 M alendronate. CONCLUSIONS: The present findings showed that alendronate inhibits calcium stone formation, suggesting that alendronate is effective for prevention of urolithiasis. This result is epoch-making for the development of new curative medicine for urinary stones. MOCK cells • Aleadroaate 20 ;/!- 0 15 f 10 f ?NS 'S 5 0 """"'' to-ll Jo• 20 15 /0 §• Jo-' M 0.33% soft agar 2m! ( containig I 00 cells ) 0.5% soft agar 2m! ( feeding layer ) IDcadronate f tNS ?NS .,.., .. , 11)-11 , ... Concentration ofbisphosphonates Source of Funding: None 1134 ?NS "'' M STONE EVENTS ARE PROPORTIONAL TO PAPILLARY PLAQUE COVERAGE Samuel C Kim*, William W Tinmouth, Indianapolis, IN; Ramsay L Kuo, Philadelphia, PA; Ryan F Paterson, Vancouver, BC, Canada; Sharon B Bledsoe, Indianapolis, IN; Joan H Parks, Fredric L Coe, Chicago, IL; James E Lingeman, Andrew P Evan, Indianapolis, IN INTRODUCTION AND OBJECTIVE: Renal papillary plaques are common in calcium stone formers and plaque coverage has been recently demonstrated to directly relate with urine calcium excretion and inversely with urine volume. We hypothesize that the amount of plaque should increase directly with stone formation. To test this, we measured papillary plaque areas in idiopathic calcium oxalate stone formers and non-stone formers and examined the clinical stone events to identify significant correlations. METHODS: Thirteen stone formers and 4 non-stone forming controls underwent papillary mapping with flexible nephroscopy. For each papillum, representative still images and MPEG movies were used to identify plaque extent and papillary borders. Plaque surface area was determined as the percent of total papillary area coverage. Stone history was obtained by personal interviews and review of medical records and radiographs. The relationships of the plaque coverage data to clinical stone events were assessed with general multivariate linear modeling. Log transformation was necessary to normalize the distribution of percent plaque coverage. THE JOURNAL OF UROLOGY® 299 RESULTS: The plaque surface area in stone formers differed significantly from non-stone formers (p<O.OOOI). Independently, the duration of stone disease and the log transformation of percent plaque coverage correlated significantly with number of stones (0.67 and 0.620, p=0.003 and 0.008). In multivariate analysis, duration of stone disease significantly correlates with the number of stones (R2=0.496, p=0.05). The addition of percent plaque coverage to the duration of stone disease increases R2 to 0.592 (p=0.002). Duration of stone disease and plaque coverage did not correlate significantly (p=0.257). CONCLUSIONS: Percent plaque coverage directly correlates with the number stones formed by a patient and is increasingly significant when corrected for duration of stone disease. Plaque coverage, however, does not correlate with duration of stone disease. These results support the hypothesis that the pathogenesis of calcium oxalate stones begins with Randall's plaques. Source of Funding: NIH grant #POI DK56788 1135 APATITE DEPOSITS IN COLLECTING DUCT LUMENS PRODUCE EPITHELIAL CELL INJURY AND INTERSTITIAL INFLAMMATION IN PATIENTS FORMING BRUSHITE RENAL STONES Andrew P Evan*, James E Lingeman, Indianapolis, IN; Fredric L Coe, Chicago, IL; Youzhi Shao, Jinzhou, China; Joan H Parks, Chicago, IL; Sharon B Bledsoe, Indianapolis, IN; Elaine M Worcester, Chicago, IL; AndreJ Sommer, Oxford, OH; Ryan F Paterson, Vancouver, BC, Canada; Ramsay L Kuo, Philadelphia, PA; Marc Grynpas, Toronto, ON, Canada INTRODUCTION AND OBJECTIVE: Stones composed of calcium phosphate (CaP) are less common than calcium oxalate (CaOx) stones. Urine supersaturation (SS) with respect to CaP is higher in CaP stone formers (SF) than in CaOx SF, largely because of higher urine pH. Because we are unsure what causes the high urine pH in CaP SF, this study will test the hypothesis that cells of the medullary collecting ducts in CaP SF are damaged, and thereby lose their ability to lower the urine pH, leading to apatite formation in the lumens of these tubules. METHODS: We performed intra operative renal papillary mapping and biopsies during percutaneous nephrolithotomy in 9 brushite SF and I patient with renal tubular acidosis (RTA). The clinical history of these patients revealed 1 patient with uric acid stone treated with potassium citrate, one had UPJ obstruction at 7 years of age; all were treated with from 1 to 9 sessions of shock wave lithotripsy to the biopsied kidney. Calcium salts (CS) were identified by light microscopy using Yasue stain while chemical composition was analyzed by Fourier Transform-Infrared (FT-IR) and x-ray diffraction techniques. RESULTS: Three distinct CS deposit patterns were identified. One site of CS deposits was in the basement membranes of the thin loops of Henle and medullary interstitium beneath the urothelium to form sites of Randall 's plaque as we have previously reported for CaOx SF. A second site of CS deposits was in medullary collecting ducts and a third at the mouths of ducts of Bellini. Extensive cellular injury and interstitial fibrosis were noted at sites of intraluminal crystal deposition. Both FT-IR and x-ray diffraction analysis revealed the crystal deposits to be hydroxy apatite with an occasional region of calcium carbonate. These patients showed changes in the gross morphology of the papilla, with "pitting" that correlated with the number of lithotripsy sessions. CONCLUSIONS: SF with brushite stones have both interstitial apatite plaque and collecting duct plugging with apatite, along with collecting duct injury, a histological pattern that differs from that found in the common CaOx SF and from the intestinal bypass SF. The clinical data suggest that multiple mechanisms may lead to collecting duct injuries, including iatrogenic, anatomical or life style effects, as well as multiple lithotripsy sessions. The histology suggests that collecting cell injury results in persistently alkaline tubular fluid, with resulting formation of intratubular apatite deposits in brushite SF. Source of Funding: NIH POI DK56788-3 1136 RISK OF UROLITHIASIS AMONG HOT-AREA WORKERS Luiz Atan*, Cassia Andreoni, Valdemar Ortiz, Edina Silva, Ricardo Pitta, Miguel Srougi, Sao Paulo, Brazil INTRODUCTION AND OBJECTIVE: Few studies have correlated the employment with risk of urinary calculi development. The present study had the objective of determining the incidence of urinary urolithiasis and metabolic abnormalities among steel industry employees whom are exposed to high temperatures in the work environment. METHODS: This study was a retrospective cross-sectional type and it consisted of two steps; step 1: the incidence of urolithiasis among I 0,326 employees was assessed, whom 1,289 came from a hot environment (temperature > 45 degrees Celsius) (group I) and 9,037 came from a regular room