螺旋CT扫描预测上尿路结石成分的体内研究

目的:研究螺旋CT对体内上尿路结石化学成分的预测价值。方法:2005年12月～2007年9月对157例上尿路结石患者在治疗前行螺旋CT平扫,测结石CT值。定量分析各种治疗方法所获取结石的化学成分。经统计学分析,找出不同成分结石的CT值范围。结果:一水草酸钙、尿酸、羟基磷灰石三种纯结石的软组织窗平均CT值分别为(851.50±188.74)HU、(446.92±47.20)HU和(835.53±110.58)HU。尿酸结石与一水草酸钙结石、尿酸结石与羟基磷灰石之间CT值的差异均有统计学意义。13例纯尿酸结石与144例尿酸含量小于70%的其他结石的CT值差异有统计学意义。以结石的软组织窗平均CT值500 HU为标准鉴别纯尿酸结石,其灵敏度为92.31%,特异度为96.53%,阳性预测值为70.59%,阴性预测值为99.29%。结论:结石的CT值可作为鉴别尿酸结石的一种方法,CT值小于500 HU的结石多考虑为尿酸结石。     

非增强螺旋CT平扫对上尿路结石成分预测的体内研究

目的 探讨非增强螺旋CT对体内上尿路结石化学成分的预测价值.方法 回顾性分析156例有结石标本的上尿路结石患者临床资料.所有患者在治疗前采用GE High speed CT/i螺旋CT机行非增强结石扫描,扫描参数为120 kV,320 mA,螺距0.6:1,扫描层厚为5 mm.在CT软组织窗测量结石平均CT值.将获取的结石样本采用红外光谱自动分析系统进行化学成分定性分析.经统计学分析,找出各种成分结石的相应CT值范围.结果 非增强螺旋CT扫描156例结石的软组织窗CT值范围为128～ 1663亨氏单位(hounsfield unit,HU).共发现纯结石57例,其中纯一水草酸钙结石28例,纯尿酸结石19例,纯羟基磷灰石10例,混合结石99例.一水草酸钙、尿酸、羟基磷灰石三种纯结石的软组织窗平均CT值分别为(915.4±142.9) HU、(469.7±55.1) HU、(868.4±168.8)HU.尿酸结石与一水草酸钙结石、尿酸结石与羟基磷灰石之间的CT值差异有统计学意义(P＜0.05).19例纯尿酸结石和137例其他成分结石的软组织窗平均CT值之间差异有统计学意义(P＜0.05).以结石的软组织窗平均CT值＜ 550 HU为标准诊断纯尿酸结石,其灵敏度为92.8％,特异度为98.1％,阳性预测值为88.5％,阴性预测值为99％,诊断符合率为98.1％.结论 非增强螺旋CT平扫用于判断上尿路结石成分效果满意.根据软组织窗CT值不同,可将体内尿酸结石与其他成分结石区分.软组织窗平均CT值＜550 HU可作为纯尿酸结石的诊断标准.     

CT检查对三聚氰胺所致婴幼儿尿路结石成分演变的预测价值和意义

目的 探讨CT检查对三聚氰胺所致婴幼儿尿路结石成分演变的预测价值和意义.方法 收集三聚氰胺所致婴幼儿尿路结石25枚.根据治疗方法,18枚肾结石分为单纯碱化治疗组(n=9枚)和综合处理组(n=9枚).采用原子吸收光谱精确测定结石中钙含量.使用螺旋CT检查体外测量婴幼儿尿路结石(实验组)和随机选择的61枚成人尿路结石(对照组)的最大CT值. 结果 婴幼儿尿路结石钙含量0.11％ ～26.30％.婴幼儿尿路结石CT值与结石钙含量呈显著正相关(r =0.855,P＜0.01).单纯碱化治疗组和综合处理组肾结石CT值分别为(162±60) HU与(783±476) HU,钙含量分别为(1.30±1.51)％与(19.83±7.48)％,组间差异有统计学意义(P＜0.01).与CT值≤400 HU的婴幼儿尿路结石比较,＞400 HU的结石钙含量显著升高[(21.71±5.27)％,(1.65±1.82)％,P＜0.01],且对单纯碱化治疗效果不好(x2=11.455,P＜0.01). 结论 三聚氰胺所致婴幼儿尿路结石成分演变的预测中,CT是一种很有价值的辅助诊断工具.临床CT值＞400HU的婴幼儿尿路结石可能由于含有更多钙而对单纯碱化治疗效果不好.     

ACCURATE DETERMINATION OF CHEMICAL COMPOSITION OF URINARY CALCULI BY SPIRAL COMPUTERIZED TOMOGRAPHY

Purpose

Choice of efficacious clinical management of symptomatic renal calculi can be facilitated by ascertaining the precise chemical composition of the calculus. Spiral computerized tomography (CT) is becoming a frequently used radiographic examination to establish the diagnosis and severity of calculus disease. Our objective for this study was to determine the precision of spiral CT in identifying the chemical composition of 6 different types of urinary calculi with region of interest measurements using spiral CT.

Materials and Methods

A total of 102 chemically pure stones were separated into 6 groups. The stones along with phantoms containing butter (fat) and jello (water) were mounted vertically in the scanner gantry. Then 1 mm. thickness scanning was performed with a high speed scanner at the 2 energy levels of 80 and 120 kV. The determination of the chemical composition was performed using the absolute CT value measured at 120 kV. and the dual kilovolt CT values measured at 80 and 120 kV. Hounsfield unit at 80 kV. - Hounsfield unit at 120 kV.).

Results

The absolute CT value measured at 120 kV. was able to identify precisely the chemical composition of uric acid, struvite and calcium oxalate stones. It was imprecise in differentiating calcium oxalate from brushite stone and struvite from cystine stone. However, dual kilovolt CT value was able to differentiate these latter stones with statistical significance (p <0.03). Uric acid stones were easily differentiated from all other stones using the absolute CT value.

Conclusions

This study demonstrates that the chemical composition of urinary calculi can be accurately determined by CT scanning in an in vitro setting.     

Determination of the chemical composition of urinary calculi by noncontrast spiral computerized tomography

Various techniques for noncontrast spiral computerized tomography (NCCT) were utilized for the determination of the Hounsefield unit (HU) values of various types of urinary calculi with the aim of determining the best technique for distinguishing various stones compositions. A total of 130 urinary stones, obtained from patients who underwent open surgery, were scanned with a multidetector row scanner using 1.25 mm collimation at two energy levels of 100 and 120 kV at 240 mA. Two post-scanning protocols were used for the HU value assignment, tissue and bone windows, for both kV values. In both protocols, three transverse planes were defined in each stone, one near the top, one in the middle, and one near the bottom. Three regions of interest (ROI) were obtained in each plane. The absolute HU value was determined by three methods: the mean of the nine ROI, the mean of the central three ROI, and the central ROI in the middle plane. Determination of the stones composition was performed using the absolute HU value measured at 120 kV, the dual CT values (HU values at 100 kV–HU values at 120 kV), and HU values/stone volume ratio (HU density). All stones were analyzed by x-ray diffraction to determine their chemical composition. After the exclusion of groups with few calculi, 47 pure stones [25 uric acid (UA), 15 calcium oxalate monohydrate (COM), seven struvite], and 60 mixed stones [15 COM 60–90%+hydroxyl apatite (HA), 14 COM 40–90%+UA, 21 UA+COM <40%, ten mixed struvite+COM+hydroxyl apatite] were included in the statistical analysis. From the least to the most dense, the pure stone types were UA, struvite, COM. Mixed UA+COM<40% calculi were less dense but insignificantly different from pure UA, while when the COM ratio was 40% their density became higher than and significantly different from pure UA, and less than but not significantly differentiated from pure COM. Mixed COM+HA were the most dense stones. Using the absolute HU values at 120 kV and HU density, we could distinguish, with statistical significance, all pure types from each other, pure UA from all mixed calculi except UA+COM <40%, pure COM from mixed UA+COM <40%, and pure struvite from all mixed stones except mixed struvite stones. Dual CT values were not as good as absolute HU values and HU density in the determination of stone composition. These results demonstrate that absolute HU values and HU density derived from CT scanning using a small collimation size could uncover statistically significant differences among all pure and most of the mixed urinary stones. This permits more accuracy in the prediction of stone composition. Moreover, this technique permits diagnostic conclusions on the basis of single CT evaluation.     

Determination of stone composition by noncontrast spiral computed tomography in the clinical setting

OBJECTIVES: Several investigators have evaluated noncontrast computed tomography (NCCT) in predicting stone composition in vitro. We assessed NCCT in predicting stone composition in patients presenting to our emergency room with flank pain and stone disease. METHODS: One hundred twenty-nine patients presenting to our university hospital with flank pain underwent renal colic protocol NCCT scans at the request of the emergency room physicians. A General Electric, high-speed advantage CT scanner was used at 120 kV, 200 mA, and 1.4:1 pitch, with collimation varying between 3 and 5 mm. Ninety-nine patients with predominantly (greater than 50%) calcium oxalate or uric acid composition after either stone passage or stone removal were identified. Each scan was analyzed by one of two radiologists, who determined the predominant attenuation for each stone. Stones once passed or retrieved were analyzed by Urocor Laboratories. The attenuation and attenuation/size ratio (peak attenuation/size in millimeters) were compared with the results of the stone analysis. RESULTS: Eighty-two calculi predominantly composed of calcium oxalate and 17 calculi predominantly composed of uric acid were identified in 99 patients. The calculi ranged in size from 1 to 28 mm. A significant difference (P = 0.017, unpaired t test) was found between the Hounsfield measurement of uric acid calculi (mean 344 +/- 152 HU) and the Hounsfield measurement of calcium oxalate calculi (mean 652 +/- 490 HU). If only the Hounsfield units from stones 4 mm or larger were compared, the data were even more compelling (P = 0.002). However, using an attenuation/size ratio cutoff of greater than 80, the negative predictive value was 99% that a stone would be predominantly calcium oxalate. CONCLUSIONS: Using peak attenuation measurements and the attenuation/size ratio of urinary calculi from NCCT, we were able to differentiate between uric acid and calcium oxalate stones.     

Physicochemical metabolic characteristics for calcium oxalate stone formation in patients with gouty diathesis

PURPOSE: We determined why calcium oxalate stones instead of uric acid stones form in some patients with gouty diathesis. MATERIALS AND METHODS: Gouty diathesis was diagnosed from absence of secondary causes of uric acid stones or low urinary pH, and reduced fractional excretion of urate with discriminant score of the relationship between urinary pH and fractional excretion of urate less than 80. From the stone registry 163 patients with gouty diathesis were identified, including 62 with uric acid stones (GD + UA) and 101 patients with calcium oxalate stones (GD + Ca). Metabolic data and 24-hour urinary chemistry study were compared between the 2 groups. RESULTS: Compared with GD + UA, GD + Ca had significantly greater urinary calcium (196 +/- 96 mg per day vs 162 +/- 82 mg per day, p <0.05) and significantly lower urinary citrate (430 +/- 228 vs 519 +/- 288 mg per day, p <0.05), resulting in higher urinary saturation of calcium oxalate. Both groups had low urinary pH (less than 5.5) and high urinary undissociated uric acid (greater than 100 mg/dl). Urinary calcium post-oral calcium load was significantly higher in GD + Ca than in GD + UA (0.227 vs 0.168 mg/dl glomerular filtrate, p <0.001). CONCLUSIONS: Calcium oxalate stones may form in some patients with gouty diathesis due to increased urinary excretion of calcium and reduced excretion of citrate. Relative hypercalciuria in GD + Ca may be due to intestinal hyperabsorption of calcium.     

Dual-energy computed tomography for the differentiation of uric acid stones: ex vivo performance evaluation

We assessed the potential of dual-energy computed tomography (CT) for the differentiation between uric acid (UA)-containing and non-UA-containing urinary stones. Forty urinary stones of 16 different compositions in two sizes (< and >/= 5 mm) were examined in an ex vivo model. Thirty stones consisted of pure calcium oxalate (whewellite or wheddellite), calcium phosphate (apatite, brushite, or vaterite), ammonium magnesium phosphate (struvite), UA, ammonium acid urate, ammonium phosphate, sodium hydrogen urate, or cystine, and ten stones were of mixed composition (UA-sodium hydrogen urate, whewellite-urate, wheddellite-urate, whewellite-brushite, or whewellite-brushite-struvite). Scans were performed using dual-source CT in a dual-energy mode with the tubes simultaneously operating at 80 and 140 kV. Two readers analysed the data with respect to stone attenuation at each energy level. The stones were classified as UA- or non-UA-containing using manual attenuation measurements and software analysis results. Sensitivity, specificity, PPV, and NPV were calculated using crystallographic stone analysis as the gold standard. Twenty-six out of 40 stones (65%) contained no UA; 14 stones (35%) contained UA. When compared with UA-containing stones, the differences in attenuation values at 80 and 140 kV were significantly (P < 0.001) higher in stones containing no UA. The software automatically mapped 39/40 stones (98%). Only one (2%) 2 mm UA-stone was missed. The software correctly classified all detected stones as UA- or non-UA-containing. The attenuation values of the missed stone were manually plotted into the analysis sheet which allowed for the correct classification of the stone (containing UA). Therefore, the sensitivity, specificity, PPV, and NPV for the detection of UA-containing stones was 100%. Ex vivo experience indicates that differentiation between UA- and non-UA-containing stones can be accurately performed using dual-source dual-energy CT.     

Hypocitraturia as a pathogenic risk factor in the mixed (calcium oxalate/uric acid) renal stones.

A small group of patients with nephrolithiasis who forms mixed (calcium oxalate and uric acid) calculi presents particular problems in their clinical management. In 3,158 stones analyzed in our laboratory, we found 158 mixed calculi in 86 of the patients. In this work, the clinical and biochemical results obtained from 27 patients with mixed stones were compared with those from 27 control patients with calcium oxalate renal lithiasis. A significant difference was found in oxalate and citrate urinary elimination (mean +/- SD) in mixed stone formers versus pure calcium oxalate stone formers: oxaluria (mg/24 h: 38 +/- 15 vs. 28 +/- 12; p less than 0.01) and citraturia (mg/24 h: 214 +/- 139 vs. 437 +/- 303; p less than 0.01). Citraturia was decreased in a high proportion (77%) in mixed stone formers, and only a reduced percentage of them (23%) presented normal values, although in the low limit of normality. As treatment and prophylactic measure, we proposed oral administration of citrates in mixed stone patients because citrate inhibits spontaneous nucleation of calcium salts and crystal growth, and it also increases the urinary pH with a consequent increase in uric acid solubility.     

双源CT多参数比较一水草酸钙结石与混合钙结石的临床价值

目的:探讨双源CT多参数比较上尿路一水草酸钙结石与混合钙结石的临床价值,为临床个体化治疗泌尿系结石提供影像学依据。方法:回顾性分析2018年1月至2019年6月在本院收治的120例上尿路结石患者的临床资料。按照结石离体行红外光谱分成一水草酸钙组(42例)和混合钙结石组(78例),所有患者术前均行双源CT检查,获得两组结...     

Serum,urinary and stone zinc,iron, magnesium and copper levels in idiopathic calcium oxalate stone patients

Many theories have been put forward to explain the mechanism of stone formation and growth. The aim of this study was to investigate the urinary, serum and stone levels of zinc, iron, magnesium, and copper in patients with calcium oxalate stones and to investigate urinary and serum element levels in healthy controls and to find a possible connection between the elements and calcium oxalate stone formation. A total of 104 patients with calcium oxalate stones ranging in age from 3 to 79 years (mean 44.0 ± 18.1) and 77 healthy controls ranging in age from 18 to 77 (mean 44.2 ± 17.9) were included in this study. The mean urinary iron and copper levels in stone patients were significantly higher than healthy controls (P = 0.000). The mean urinary zinc and magnesium levels in healthy controls were significantly higher than stone patients (P = 0.000). There was no significant difference in the serum levels of magnesium and copper in stone patients and healthy controls. Serum zinc and iron level were significantly high in healthy controls as compared to stone patients. Each stone had all 4 elements. Zn and Mg have inhibitory effect on calcium oxalate stone formation. Fe and Cu could be promotor of the calcium oxalate stone formation.     

Calcium stone disease: a multiform reality

In calcium renal stones, calcium oxalate and calcium phosphate in various crystal forms and states of hydration can be identified. Calcium oxalate monohydrate (COM) or whewellite and calcium oxalate dihydrate (COD) or weddellite are the commonest constituents of calcium stones. Calcium oxalate stones may be pure or mixed, usually with calcium phosphate or sometimes with uric acid or ammonium urate. The aim of this study was to compare the clinical and urinary patterns of patients forming calcium stones of different composition according to infrared spectroscopic analysis in order to obtain an insight into their etiology. The stones of 84 consecutive calcium renal stone formers were examined by infrared spectroscopy. In each patient, a blood sample was drawn and analysed for serum biochemistry and a 24-h urine sample was collected and analysed for calcium, phosphate, oxalate, citrate and other electrolytes. We classified 49 patients as calcium oxalate monohydrate (COM) stone formers, 32 as calcium oxalate dihydrate (COD) stone formers and three as apatite stone formers according to the main component of their stones. Patients with COM stones were significantly older than patients with COD stones (P<0.002). Mean daily urinary calcium and urinary saturation with respect to calcium oxalate were significantly lower in patients with COM than in those with COD stones (P<0.000). Patients with calcium oxalate stones containing a urate component (10%) presented with higher saturation (P<0.012) with respect to uric acid in their urine (and lower with respect to calcium oxalate and calcium phosphate, respectively P<0.024 and P<0.003) in comparison with patients without a urate component in the stone. Patients with calcium oxalate stones with a calcium phosphate component (15%) showed higher (P<0.0016) urinary saturation levels with respect to calcium phosphate (and lower with respect to uric acid (P<0.009), compared with patients forming stones without calcium phosphate or with a low calcium phosphate component. Patients with calcium stones mixed with urate had a significantly lower urinary pH (P<0.002) and urinary calcium (P<0.000), and patients with calcium phosphate >15%, higher urinary pH (P<0.004) and urinary calcium (P<0.000). In conclusion, in the evaluation of the individual stone patient, an accurate analysis of the stone showing its exact composition and the eventual presence of minor components of the stone is mandatory in order to plan the correct prophylactic treatment. Patients with calcium stones could require various approaches dependent on the form and hydration of the calcium crystals in their stones, and on the presence of minor crystalline components that could have acted as epitaxial factors.     

Effect of cranberry juice consumption on urinary stone risk factors

PURPOSE: We evaluated the effect of cranberry juice on urinary stone risk factors. MATERIALS AND METHODS: A total of 12 normal subjects and 12 calcium oxalate stone formers underwent 2, 7-day phases of study in random order while on a controlled metabolic diet. Subjects ingested 1 l of cranberry juice (CBJ) daily in 1 phase and 1 l of deionized water in the other phase. On the last 2 days of each phase 2, 24-hour urine collections and blood samples were obtained for stone risk factors and serum chemistries. RESULTS: No significant differences were found between normal subjects and stone formers in response to CBJ and, therefore, the groups were combined. CBJ significantly increased urinary calcium (from 154 to 177 mg per day, p =0.0008) and urinary oxalate (from 26.4 to 29.2 mg per day, p =0.04), thereby increasing urinary saturation of calcium oxalate by 18%. Urinary citrate was unchanged and urinary magnesium increased slightly. Urinary pH decreased (from 5.97 to 5.67, p =0.0005), and urinary ammonium, titratable acidity and net acid excretion increased during CBJ ingestion. Urinary uric acid decreased (from 544 to 442 mg per day, p <0.0001) as did serum uric acid. Thus, the urinary saturation of brushite and monosodium urate was reduced by CBJ but the amount of undissociated uric acid increased. CONCLUSIONS: CBJ exerts a mixed effect on urinary stone forming propensity. It reduces urinary pH likely by providing an acid load and decreases urinary uric acid perhaps by retarding urate synthesis. Overall CBJ increases the risk of calcium oxalate and uric acid stone formation but decreases the risk of brushite stones.     

Stone fragility: its therapeutic implications in shock wave lithotripsy of upper urinary tract stones

OBJECTIVE: To analyse the impact of stone composition on stone fragility (fragmentation) and clearance of upper urinary tract stones after shock wave lithotripsy (SWL). MATERIAL AND METHODS: Between 1st July 1998 and 31st July 2001, 300 renal and ureteric units of 290 patients (10 being bilateral) underwent SWL for upper urinary tract calculi. The degree of fragmentation was divided into four types: (I) Excellent, (II) Good, (III) Fair and (IV) No fragmentation. Stone composition was done by X-ray diffraction crystallography. A statistical comparison was made between degree of fragmentation, number of shock waves delivered, voltage setting, number of sessions required and requirements of adjuvant procedures according to the stone composition. RESULTS: Stone analysis revealed that 90% of the patients had calcium oxalate stones. Of these 80% were calcium oxalate monohydrate (COM) and 20% calcium oxalate dehydrate (COD). Struvite, apatite and uric acid stones comprised of 6%, 3% and 1% respectively. Type-I fragmentation was achieved up to 63.96%, 50% and 100% in COD, struvite and uric stones respectively as compared to 44.9% and 44.44% for COM and apatite stones. Type-III fragmentation was seen up to 8.79% and 33.3% respectively in COM and apatite as compared to 5.55% or less in other types of the stones suggesting that COM and apatite stones produce larger fragments. The mean number of shock waves, voltage and number of treatments was significantly higher for COM and apatite stones (p value < 0.005) with a stone free rate of only 65-66% and 65-68% respectively at three months (p value < 0.001). Similarly the number of adjuvant procedures required in COM alone was more, i.e. 31 as compared to 17 procedures in rest of the other kinds of stones (p value < 0.05). CONCLUSION: Stone composition in Indian subcontinent is different from the western world. Fragility of a stone varies with the composition of the stone and affects the therapeutic results.     

上尿路结石复发原因分析及其治疗(附42例报告)

目的:探讨泌尿系结石复发的原因及其处理措施。方法:回顾性分析2005年1月～2010年5月在我院接受治疗的42例上尿路复发结石患者临床资料,并对其尿石成分进行分析,对血、尿理化指标及代谢指标进行检测。结果:术后复发结石成分中,与原发结石成分相同者34例;与原发结石成分不同者8例,其中1例为尿流改道术后(草酸钙结石变为尿酸结石),1例为ESWL术后(草酸钙结石变为尿酸结石),3例为开放取石术后(草酸钙结石变为感染结石及尿酸结石),2例为输尿管碎石取石术后(尿酸结石变为感染结石)。在血、尿理化检测中,糖尿病8例,尿路感染7例,肥胖6例,甲状旁腺机能亢进3例。结论:根据复发性尿路结石的临床特点及诱发因素,采取针对性措施,选择合理的治疗方式,可以提高治疗效果。     

Essential arterial hypertension and stone disease.

BACKGROUND: Cross-sectional studies have shown that nephrolithiasis is more frequently found in hypertensive patients than in normotensive subjects, but the pathogenic link between hypertension and stone disease is still not clear. METHODS: Between 1984 and 1991, we studied the baseline stone risk profile, including supersaturation of lithogenic salts, in 132 patients with stable essential hypertension (diastolic blood pressure of more than 95 mm Hg) without stone disease and 135 normotensive subjects (diastolic blood pressure less than 85 mm Hg) without stone disease who were matched for age and sex (controls). Subsequently, both controls and hypertensives were followed up for at least five years to check on the eventual formation of kidney stones. RESULTS: Baseline urine levels in hypertensive males were different from that of normotensive males with regards to calcium (263 vs. 199 mg/day), magnesium (100 vs. 85 mg/day), uric acid (707 vs. 586 mg/day), and oxalate (34.8 vs. 26.5 mg/day). Moreover, the urine of hypertensive males was more supersaturated for calcium oxalate (8.9 vs. 6.1) and calcium phosphate (1.39 vs. 0.74). Baseline urine levels in hypertensive females were different from that of normotensive females with regards to calcium (212 vs. 154 mg/day), phosphorus (696 vs. 614 mg/day), and oxalate (26.2 vs. 21.7 mg/day), and the urine of hypertensive females was more supersaturated for calcium oxalate (7.1 vs. 4.8). These urinary alterations were only partially dependent on the greater body mass index in hypertensive patients. During the follow-up, 19 out of 132 hypertensive patients and 4 out of 135 normotensive patients had stone episodes (14.3 vs. 2.9%, chi-square 11.07, P = 0.001; odds ratio 5.5, 95% CI, 1.82 to 16.66). Of the 19 stone-former hypertensive patients, 12 formed calcium calculi, 5 formed uric acid calculi, and 2 formed nondetermined calculi. Of the urinary factors for lithogenous risk, those with the greatest predictive value were supersaturation of calcium oxalate for calcium calculi and uric acid supersaturation for uric acid calculi. CONCLUSIONS: A significant percentage of hypertensive subjects has a greater risk of renal stone formation, especially when hypertension is associated with excessive body weight. Higher oxaluria and calciuria as well as supersaturation of calcium oxalate and uric acid appear to be the most important factors. Excessive weight and consumption of salt and animal proteins may also play an important role.     

广东东莞地区416例泌尿系结石成分分析

目的 应用红外光谱法测定东莞地区泌尿系结石化学成分,探讨本地区泌尿系结石患者的尿路结石成分特点,为本地区泌尿系结石的深化治疗、防止结石复发及预防提供科学依据.方法 收集经自行排出、碎石后排出或手术中取出的泌尿系结石标本416例,应用溴化钾压片技术的红外光谱法对其化学成分进行定性分析.结果 416例泌尿系结石患者中男性居多,占66.8%(278/416),女性占33.2%(138/416);上尿路结石占88.2%,下尿路结石(膀胱结石居多)占11.8%;结石成分定性分析共检测出一水草酸钙、二水草酸钙、碳酸磷灰石、无水尿酸、六水磷酸铵镁和尿酸铵6种化学成分.单一成分结石163例(一水草酸钙/无水尿酸/碳酸磷灰石/六水磷酸铵镁:98/56/6/3),占39.2%;混合成分结石253例,占60.8%,其中以草酸钙和碳酸磷灰石的混合结石为主(188/253).所有结石标本中草酸钙检出率最高,占80.5%(335/416),其次为碳酸磷灰石(49.3%)及无水尿酸(17.3%);膀胱结石成分以一水草酸钙或无水尿酸为主.结论 东莞为全国泌尿系结石最高发地区,其结石成分以草酸钙和碳酸磷灰石为主,单一成分结石亦占相当比例.尿路结石成分分析对了解结石成因可提供重要的线索,对临床制定个性化治疗方案、预防结石形成及复发具有重要意义.     

Role of the urinary calcium in the growth of calcium stone

We analyzed the relationship between the rate and clinical factors. The growth rate per year of the stone was measured by Nabeshima's method in 29 male patients with renal calcium stones including 7 pure calcium oxalate (CaOx) stones and 22 mixed calcium oxalate and calcium phosphate (CaOx-CaP) stones. The 24-hour urinary excretion of calcium, phosphate, uric acid and magnesium were assayed under an ambulatory free diet in 5 patients with CaOx stones and 15 with CaOx-CaP stones. The relationship between the growth rate and the urinary excretion of stone-forming parameters was examined. We found a significant positive correlation between the growth rate of calcium stones and the urinary excretion of calcium (p<0.02). In addition, the growth rate of CaOx-CaP stone was significantly higher than that of pure CaOx stone (p<0.05). In conclusion, urinary calcium is important for the growth of renal calcium stones.     

Matrix glycosaminoglycan in urinary stones

At first, urinary stones were classified according to their inorganic components (apatite, struvite, calcium oxalate monohydrate, calcium oxalate dihydrate and uric acid). Then, matrix glycosaminoglycan was extracted from the stones in each group and was analyzed by 2-dimensional electrophoresis. There were differences in the glycosaminoglycan content of matrices among different groups of urinary stones. The principal matrix glycosaminoglycan content consisted of hyaluronic acid in apatite and struvite stones, heparan sulfate in calcium oxalate monohydrate and uric acid stones, and hyaluronic acid and heparan sulfate in calcium oxalate dihydrate stones. We conclude that hyaluronic acid and/or heparan sulfate has an important role in urinary stone formation.     

Stone forming risk of calcium citrate supplementation in healthy postmenopausal women

PURPOSE: We evaluated the effect of calcium citrate supplementation alone or in combination with potassium citrate on the stone forming propensity in healthy postmenopausal women. MATERIALS AND METHODS: A total of 18 postmenopausal women without stones underwent a randomized trial of 4 phases comprised of 2 weeks of treatment with placebo, calcium citrate (400 mg calcium twice daily), potassium citrate (20 mEq twice daily), and calcium citrate and potassium citrate (at same doses). During the last 2 days of each phase urine was collected in 24-hour pools for complete stone risk analysis. RESULTS: Compared to placebo, calcium citrate increased urinary calcium and citrate but decreased urinary oxalate and phosphate. Urinary saturation of calcium oxalate, brushite and undissociated uric acid did not change. Potassium citrate decreased urinary calcium, and increased urinary citrate and pH. It decreased urinary saturation of calcium oxalate and undissociated uric acid, and did not change the saturation of brushite. When calcium citrate was combined with potassium citrate, urinary calcium remained high, urinary citrate increased even further and urinary oxalate remained reduced from the calcium citrate alone, thereby marginally decreasing the urinary saturation of calcium oxalate. Urinary pH increased, decreasing urinary undissociated uric acid. The increase in pH increased the saturation of brushite despite the decrease in urinary phosphorus. CONCLUSIONS: Calcium citrate supplementation does not increase the risk of stone formation in healthy postmenopausal women. The co-administered potassium citrate may provide additional protection against formation of uric acid and calcium oxalate stones.