Comparison of urinary tract infection in calcium oxalate and calcium phosphate stone formers

To compare the frequency of urine infection in calcium oxalate and calcium phosphate stone formers, we reviewed charts from patients whose last renal stone submitted for analysis was predominantly composed of calcium phosphate in 118 and of calcium oxalate in 223. Positive cultures were commoner, but not significantly, in the phosphate than the oxalate stone formers, both in men (17 vs. 7.6%) and women (22 vs. 15%). Bacteria frequently producing urease were found in only 4% of the phosphate group. Urine leucocytes were slightly more frequent in the oxalate group for men and significantly so for women. The results do not support the concept that calcium phosphate stones are mainly due to infection with urease-producing or other bacteria.     

Detection of Proteus mirabilis Urease Gene in Urinary Calculi by Polymerase Chain Reaction

Background: Urea-splitting microorganisms cannot always be detected by stone or urine culture in patients with infection stones. Detection of genetic elements within the calculi by the polymerase chain reaction (PCR) may be a useful alternative. In this study, we assessed the usefulness of the PCR method in detecting the urease gene specific to Proteus mirabilis in urinary calculi.
Methods: Thirty-eight metabolic stones (calcium oxalate and/or calcium phosphate, uric acid, or cystine) and 49 struvite stones were examined. The PCR was applied with DNA extracted by boiling pulverized stone pieces.
Results: Of the 87 stones, PCR demonstrated the presence of the P. mirabilis urease elements ureC1 and ureC2 in 1 7, all of which were struvite. Stone culture and urine culture had been performed in 22 and 46 struvite stone cases, respectively, and the PCR was positive in all of the 10 culture-positive calculi and also in two calculi from which P. mirabilis was not isolated.
Conclusion: PCR was reliable and convenient for detecting P. mirabilis in desiccated struvite calculi. Study to detect other species such as Ureaplasma or Corynebacterium would be useful in elucidating the role of bacterial infection in the formation of these stones.     

Kidney stones during pregnancy: an investigation into stone composition

Kidney stones can be a source of considerable morbidity for pregnant women. Although there is a body of literature confirming that different stone compositions predominate for different age and sex cohorts, there have been no similar reports characterizing the nature of stone disease during pregnancy. We performed a multi-institutional study to define the composition of renal calculi diagnosed during pregnancy. We retrospectively reviewed the records from two stone referral centers of all patients diagnosed with a de novo kidney stone during pregnancy who underwent a procedure for the purpose of stone removal from June 2001 through September 2007. A total of 27 patients were identified, with a mean age of 26.8 years (range, 21-34). Twenty patients (74%) had no history of prior stone formation. Seven patients (26%) had previously formed stones, although none of these patients had a known kidney stone at the time they became pregnant. Stones were removed in the first, second, third trimester and immediately post-partum in 4, 52, 22, and 22% respectively. Stone removal was performed without complication in all cases. Analysis found that in 74% of all cases (20 patients) stones were composed predominantly of calcium phosphate (hydroxyapatite). In 26% of cases, (7 patients) the stones were composed predominantly of calcium oxalate. Of the seven patients with prior stone history, three patients had previously formed calcium phosphate stones and four patients had previously formed calcium oxalate stones. Calcium oxalate calculi are the most common stone in non-pregnant women of a comparable age as our subjects. However, our present data suggest that stones detected during pregnancy are most commonly composed of calcium phosphate (hydroxyapatite). Indeed, it is the minority of stones that are composed of calcium oxalate. Although the reason for this unusual preponderance of calcium phosphate calculi is unclear, physiologic alterations that occur during pregnancy may be influential.     

The bacteriology of operated renal stones

In a group of patients consecutively operated on for renal stones, more than half of the patients had urinary tract infection. In a significant number of the patients with infection stones containing magnesium ammonium phosphate, no urease-producing microorganism could be cultured. Escherichia coli was on the other hand rather frequently cultured from the stone in these patients. This suggests the possibility that E. coli might be involved in stone formation. The correlation between stone and voided urine cultures was incomplete. It is thus important to perform stone cultures. This could be done without loss of accuracy by culturing crushed stones.     

232例湖北地区泌尿系结石红外光谱成分分析

目的：分析湖北地区泌尿系结石化学成分的构成,为本地区结石的防治提供依据。方法：采用结石红外光谱自动分析系统对2011年11月～2012年8月期间收集到的湖北地区泌尿系结石232例进行成分分析。结果：232例结石中,各成分的检出率为：一水草酸钙（COM）85．34％,二水草酸钙（COD）62．93％,碳酸磷灰石（CA）24．14％,无水尿酸（UA）12．93％,二水磷酸氢钙（PH）4．31％,磷酸铵镁（MAP）6．90％,黄嘌呤1．29％,胱氨酸（CYS）1．29％,方解石0．86％,尿酸铵（AU）0．86％。含草酸钙成分结石86．21％,含磷酸钙成分结石28．45％,含磷酸铵镁成分结石6．90％,含尿酸成分结石13．79％,含胱氨酸成分结石1．29％。混合成分结石181例（78．02％）,尿路结石发病男性多于女性,男女比例为3．14：1。结论：湖北地区泌尿系结石以混合性结石为主,COM检出率最高,其次为COD。结石成分分析对于结石的防治有重要意义。     

复杂性肾结石化学成分分析(附84例报告)

目的 :分析复杂性肾结石化学成分特点 ,为预防其复发提供依据。方法 :对 84例在我院行微经皮肾镜取石术的复杂性肾结石患者 (纳入标准为鹿角形结石、单肾或双肾多发性结石且最大结石直径 >2 .5cm)进行结石化学成分分析 ,同时收集相关临床资料。结果 :80例 (95 .2 % )为含钙混合性结石和感染结石 ,其中草酸钙加磷酸钙 30例 (35 .7% ) ;草酸钙加尿酸 14例 (16 .7% ) ;草酸钙加磷酸钙加尿酸 10例 (11.9% ) ,草酸钙加磷酸钙加胱氮酸 1例 ;含钙结石并发感染结石 14例 (16 .7% ) ;感染结石 11例 (13.1% )。 4例 (4 .8% )为单一成分。结论 :体积较大的复杂性肾结石成分复杂 ,生长过程中常多种病因参与 ,应加强其病因诊断和针对多种病因采用积极的预防性治疗     

Some data on urinary stones which were passed.

Out of a group of 979 patients with urinary calculi, 175 had passed their stone(s). Comparison of data for stones which had been passed with data for the whole group shows many significant differences. Calculi composed entirely of calcium oxalate are more likely to be expelled than any other composition variety. The chance of this happening is 1 in 3 and it is even higher when the person is under 50 years of age. The probability of calculi composed of calcium oxalate+calcium phosphate being expelled is 1 in 5 and this also increases for younger patients. Infection stones consisting of calcium phosphate+struvite have only 1 in 19 chance of being passed. Many of the stones passed (130) are under 0.10 g in weight. However, there is a similar relationshp between composition and weight among both the stones that were passed and the whole group. In both groups, pure oxalate stones are the lightest, infection stones are the heaviest and stones composed of calcium phosphate and calcium phosphate+calcium oxalate are of intermediate weight.     

SEQUENTIAL ANALYSIS OF RECURRENT CALCIUM CALCULI BY INFRARED SPECTROSCOPY

Background: While the incidence of calcium urolithiasis increases, the precise mechanism of calcium oxalate stone formation is still controversial. Is the composition of a recurrent calcium oxalate stones always the same as previous ones? There are few reports that specifically address the question by study of sequential changes of the composition of recurrent calcium calculi. Method: From our medical records 70 patients with a history of two or more recurrent episodes of calcium oxalate stone disease were selected and the analyses of 190 stones were reviewed. Infrared spectroscopic analysis was done using a Perkin Elmer 1740 spectrophotometer. Results: Calcium oxalate monohydrate were detected in 63 stones, calcium oxalate dihydrate in 12, calcium oxalate monohydrate mixed with dihydrate in 28, calcium oxalate monohydrate mixed with calcium phosphate in 30, calcium oxalate dihydrate mixed with calcium phosphate in 20, calcium oxalate monohydrate mixed with dihydrate and calcium phosphate in 20, calcium oxalate monohydrate mixed with dihydrate and calcium phosphate in 37. Alterations of stone components during follow-up were found in 43 stones from 40 patients. The shift of a main composition from calcium oxalate monohydrate to calcium oxalate dihydrate was found in 24 stones and vice versa in 19 stones. Conclusions: Sequential changes of the compositions of recurrent calcium calculi are highly likely to occur with time in individual recurrent calcium stone formers. Calcium oxalate monohydrate was a most common component of the studied recurrent calcium stones.     

Evaluation of chemical composition of urinary calculi by conventional radiography

BACKGROUND AND PURPOSE: The choice of the most efficient treatment modality for renal calculi could be facilitated by determining the precise chemical stone composition before treatment. We investigated the possibility of using conventional X-ray imaging to determine stone composition and to find a simple method of predicting stone fragility for treatment planning. MATERIALS AND METHODS: The X-ray density of 92 stones with known infrared spectroscopy analyses (calcium oxalate monohydrate, calcium oxalate dihydrate, struvite, and calcium phosphate) was retrospectively investigated by scanning the films with a digital camera. The data analysis was done using a commercially available graphics program to compare the total gray-scale levels of the stones. RESULTS: There was a significant difference in the mean gray-scale level of calcium phosphate and calcium oxalate stones (P < 0.01). The mean gray-scale difference between calcium oxalate dihydrate and calcium oxalate monohydrate was also significant (p < 0.02). All calcium oxalate, struvite, and calcium phosphate stones were correctly identified. Of the calcium oxalate monohydrate and calcium oxalate dihydrate stones, 98.4% and 66.6%, respectively, were correctly identified. CONCLUSION: The method allows a reliable diagnosis of stone composition from radiographs, which can be useful in stone treatment planning.     

Analysis of spontaneously passed urinary tract stones

Most studies on epidemiology, composition, and recurrence of renal calculi include both spontaneously passed calculi and those retrieved after surgical manipulation or shock wave lithotripsy. The present study exclusively focused on epidemiology, composition, and recurrence of spontaneously expelled stones in patients from North and East Mallorca (Spain) which represents a geographically specific non-urban region of a developed country. The study involved 136 patients who spontaneously passed 205 renal calculi. All calculi were classified and sub-classified according to composition after macroscopic and microscopic examination. We also analyzed prevalence, gender, age, and stone recurrence rate over a period of 3 years. The peak incidence of spontaneously stone passage is within the fourth to sixth decade. Overall male to female ratio was 3/1. Calcium oxalate was the most prevalent composition (64.8%) followed by uric acid (25.3%), mixed stones (5.3%) and calcium phosphate calculi (4.3%). Uric acid stones were the most recurrent (50%) followed by calcium oxalate monohydrate papillary calculi (26.4%), calcium oxalate monohydrate un-attached calculi (19.2%), calcium oxalate dihydrate calculi (18.3%), calcium phosphate calculi (14%), and mixed calculi (12.5%). In conclusion, spontaneously passed stones in Mallorcan population have similar epidemiology, composition, and recurrence rate from that found in other developed countries. Calcium oxalate stones are largely the most spontaneously passed type of calculi and uric acid stones are the most frequently recurred. These findings are also found to be similar to those reported in previous studies examining both spontaneously and non-spontaneously passed stones.     

The relation between urinary tract infections and stone composition in renal stone formers

During a seven-year period (1975-1981) a total of 1325 patients hospitalized for stone disease were studied as to the occurrence of positive urine cultures. Urinary stones from 535 surgically treated patients were analyzed with infrared spectrophotometry and the relationships between stone composition, level of surgery and bacteriological strains were studied. Positive urinary cultures were found in 34% of the surgically treated patients and in 21% of those not operated upon. Among the surgically treated patients with urinary tract infection (UTI) E. coli was the most frequent microorganism (35%), followed by Proteus (28%). Patients with Proteus infection had the highest frequency of UTI episodes, most of which occurred before hospitalization. There was a higher frequency of magnesium ammonium phosphate (MAP) calculi among patients with Proteus infection than among those with non-Proteus infection, in whom no difference in stone composition was found. Patients infected with E. coli had more phosphate-containing stones (CaP+MAP) than non-infected patients. The highest frequency of oxalate calculi (CaOx+CaOx/CaP) was found among patients without infection. No E. coli infections were seen in male patients with CaP and MAP calculi. MAP stones were most often found in the kidney and oxalate stones in the ureter.     

Spectrum of stone composition: structural analysis of 1050 upper urinary tract calculi from northern India

BACKGROUND: The purpose of the present paper was to study the spectrum of stone composition of upper urinary tract calculi by X-ray diffraction crystallography technique, in patients managed at All India Institute of Medical Sciences. METHODS: Between 30 April 1998 and 31 March 2003, a total of 1050 urinary calculi (900 renal, 150 ureteric) were analyzed. The stone fragments were collected after extracorporeal shock-wave lithotripsy, or retrieval by endoscopic (percutaneous nephrolithotomy, ureterorenoscopy), laparoscopic and various open surgical procedures. The structural analysis of the stones was done using X-ray diffraction crystallography. RESULTS: Four types of primary and three secondary X-ray diffraction patterns were obtained. The primary patterns were as follows. Pattern A, well organized crystalline structure; pattern B, moderately organized crystalline structure; pattern C, poorly organized crystalline structure; pattern D, very poorly organized crystalline structure. The three secondary patterns mainly highlighted the mixed variety of stones. These patterns were further analyzed and compared with standard X-ray diffraction (powder) photographs. Of the 1050 stones analyzed, 977 (93.04%) were calcium oxalate stones, out of which 80% were calcium oxalate monohydrate (COM) and 20% were calcium oxalate dihydrate (COD). Fifteen were struvite (1.42%) and 19 were apatite (1.80%). Ten were uric acid stones (0.95%) and the remaining 29 (2.76%) were mixed stones (COM + COD and calcium oxalate + uric acid, calcium oxalate + calcium phosphate, and calcium phosphate + magnesium ammonium phosphate). A total of 89.98% of staghorn stones were made of oxalates (COM/+COD) and only 4.02% were struvite. CONCLUSION: Urinary stone disease in the Indian population is different from that in Western countries, with a larger percentage of patients having calcium oxalate stones, predominantly COM. Also, the majority of staghorn stones (89.98%) were made of oxalates.     

The severity of infection stones compared to other stones in the upper urinary tract

A retrospective study of the case records of 391 adult patients with spontaneously passed or surgically removed concrements from the upper urinary tract during the period 1982-1983 was performed. According to chemical analysis, 66% of the stones were calcium stones, 30% were infection stones, 4% were uric acid/urate stones and 1% were cystine stones. Of the infection stones 12 (10%) were staghorn calculi. The infection stones placed a greater strain on the patients than the calcium stones. Thus, infection stones were significantly more often recurrent stones and required surgery significantly more often than the calcium stones. Only 6% of the patients with infection stones had proved abnormalities predisposing to upper urinary tract infection. Urinary tract infection with a urease-producing microorganism was detected in only 52% of the patients with infection stones. As infection with a urease-producing microorganism is a prerequisite for the formation of infection stones in the urinary tract a careful microbiological investigation to find and treat the infection responsible for the stone formation is mandatory.     

Calcium phosphate: an important crystal phase in patients with recurrent calcium stone formation?

Summary Stone and urine composition were analysed in 75 men and 40 women with recurrent calcium oxalate stone disease (group R) and in 48 men and 19 women who had formed only one calcium-oxalate-containing stone (group S). Patients who had developed stones with a large fraction of calcium phosphate were significantly more frequent in group R than in group S. There was furthermore a higher excretion of calcium and higher calcium oxalate supersaturation levels in patients with stones containing more than 25% calcium phosphate. It was concluded from these observations that the calcium phosphate content of renal stones might be a useful factor in predicting the future course of the disease.     

双源CT体内预测尿路结石成分的临床应用研究(附40例报告)

目的:探讨双源CT对体内肾结石化学成分的预测价值。方法:选择泌尿系结石患者40例,男30例,女10例;平均年龄46岁。其中肾结石31例,上段输尿管结石9例。采用西门子炫速双源CT(第二代双源CT)(Siemens SOMATOM Definition Flash Dual-source CT,DSCT)进行术前检查,扫描条件采用0.6mm层厚无间距扫描,所得数据经拆薄重建后传至随机工作站进行重建及双能量分析。所有患者均采用经皮肾镜取石术取得结石样本,采用傅立叶变换红外光谱法分析结石样本成分,进行统计分析,以判断DSCT预测结石成分的准确性。结果:红外光谱检测单一结石成分12例,混合结石成分28例。与红外光谱分析结果相比,DSCT检测含草酸钙成分结石32例,鉴别草酸钙结石的敏感性为96.8%,特异性为80%。DSCT检测含磷酸盐成分结石32例,鉴别磷酸盐结石的敏感性为96.6%,特异性为63.6%。DSCT检测含尿酸结石5例,鉴别尿酸结石的敏感性和特异性为100%。1例胱氨酸结石的准确率100%。结论:术前双源CT扫描成分分析能够有效区分尿路结石化学成分,如尿酸结石、草酸盐结石、磷酸盐结石和胱氨酸结石,与红外光谱结石分析结果有较好的一致性。这对于合理选择治疗方式,避免不必要的无效治疗,提高疗效,节省费用,减少并发症等有重要意义,具有临床推广价值。     

2015~2018年达州市尿路结石患者人口学特征及结石化学成分分析

目的对2015~2018年四川省达州地区尿路结石患者人口学特征及结石化学成分进行分析。方法选择2015年1月至2018年12月四川省达州市中西医结合医院进行治疗的583例尿路结石患者,经体外振动波碎石、手术、自排等方式获得结石标本583份进行研究。所有患者入组后均采集性别、年龄、居住地等一般资料,获取结石标本后以结石红外光谱自动分析系统对其化学成分进行分析。结果583例患者中单纯性结石289例(49.75%),二重混合性结石288例(49.40%),三重混合性结石6例(1.03%)。从结石成分分布上看草酸钙占比最高,为94.00%,其次是磷酸磷灰石37.04%、尿酸及尿酸铵14.92%。女性患者磷酸铵镁占比为4.31%,明显高于男性的1.35%(P<0.05)。其他成分不同性别患者分布情况差异无统计学意义(P>0.05)。60岁以下的患者结石成分为草酸钙占比为96.69%,明显高于60岁及以上者的89.55%(P<0.05)。其他成分不同年龄段患者分布情况差异无统计学意义(P>0.05)。城镇居民患者草酸钙、磷酸磷灰石占比分别为96.69%、40.38%,均明显高于农村居民的89.82%、28.74%(P<0.05)。其他成分不同居住环境患者分布情况差异无统计学意义(P>0.05)。结论四川达州地区尿路结石患者结石化学成分易草酸钙为主,其次为磷酸磷石灰石、尿酸及尿酸铵。不同性别、年龄、居住环境对尿路结石化学成分分布有一定的影响。     

Endotoxin content in renal calculi

PURPOSE: Manipulation of infection calculi (struvite and calcium apatite) can cause the sepsis syndrome due to endotoxemia or bacteremia. We sought to determine whether concentrations of endotoxin sufficient to produce the sepsis syndrome could be embedded in renal infection stones. MATERIALS AND METHODS: Fragments of infection and noninfection renal calculi were processed and assayed for endotoxin concentration. Endotoxin concentrations, recorded as endotoxin units per gm. calculus, were converted to ng. (10 endotoxin units = 1 ng.). Urine culture results were available for some patients with infection stones. RESULTS: A total of 34 renal calculi (16 infection and 18 noninfection) were evaluated. The composition of 62.5% of the infection stones was struvite, whereas 50% of the noninfection stones were calcium oxalate monohydrate. Mean endotoxin concentration in infection calculi was 12,223 ng./gm. stone (range 0.6 to 50,000), compared to 340.3 ng./gm. stone (range 0 to 3,490) in noninfection calculi. The endotoxin content difference was significant (p = 0.001). Urine culture results available from 9 patients with infection stones did not correlate with endotoxin concentrations. CONCLUSIONS: Large endotoxin concentrations can be found in renal infection calculi. Noninfection stones can contain endotoxin but in much lower amounts. Massive endotoxin release could occur with infection stone manipulation, possibly producing increased serum endotoxin concentrations similar to those seen in gram-negative sepsis. Anti-endotoxin strategies may be beneficial in preventing and treating stone induced endotoxemia and the sepsis syndrome.     

Etiology and treatment of urolithiasis

Nephrolithiasis is a heterogeneous disorder, with varying chemical composition and pathophysiologic background. Although kidney stones are generally composed of calcium oxalate or calcium phosphate, they may also consist of uric acid, magnesium-ammonium phosphate, or cystine. Stones develop from a wide variety of metabolic or environmental disturbances, including varying forms of hypercalciuria, hypocitraturia, undue urinary acidity, hyperuricosuria, hyperoxaluria, infection with urease-producing organisms, and cystinuria. The cause of stone formation may be ascertained in most patients using the reliable diagnostic protocols that are available for the identification of these disturbances. Effective medical treatments, capable of correcting underlying derangements, have been formulated. They include sodium cellulose phosphate, thiazide, and orthophosphate for hypercalciuric nephrolithiasis; potassium citrate for hypocitraturic calcium nephrolithiasis; acetohydroxamic acid for infection stones; and D-penicillamine and alpha-mercaptopropionylglycine for cystinuria. Using these treatments, new stone formation can now be prevented in most patients.     

Formation of the staghorn calculi

To study the process of formation of staghorn calculi, 58 patients with staghorn calculi were evaluated clinically and the removed stones were studied architecturally. Of 35 patients with infection stones composed of struvite and/or apatite in the nuclei as well as peripheral layers, 18 had identified predisposing factors related to infection. Of 13 patients with infection stones containing calcium oxalate in the nuclei, 7 had predisposing factors of infection but only 2 had metabolic disorders. The patients with infection stones who had no predisposing factors may have transient or subclinical abnormalities. Initial stone formation of oxalate may also be one of the predisposing factors of infection. Most of the patients with staghorn calculi composed of uric acid, oxalate and cystine, had metabolic disorders related to these substances. Large numbers of bacteria and large amounts of organic matrix were found extensively within infection stones and were thought to be important components as well as crystals. Metabolic stones contained little matrix. In this case crystal aggregation is thought to play the most important role in stone formation.     

Urolithiasis in Okinawa, Japan: A relatively high prevalence of uric acid stones

AIM: The aim of the present study was to investigate the composition of urinary tract stones in patients from Okinawa, the most southern island group of Japan. METHODS: The study was conducted by 12 hospitals in Okinawa. A total of 1816 urinary tract calculi were obtained from 1816 patients (1323 males; 493 females). The patients had a mean age of 53 +/- 15.3 years (mean +/- SD). The calculi were examined to determine their chemical composition. Stone samples were analyzed by computed infrared spectrophotometer. RESULTS: Pure stones comprised 58.4% of the total, with calcium oxalate stones accounting for 40% (21% monohydrate [whewellite]; 6.6% dihydrate [weddellite]; and 12.4% combined monohydrate and dihydrate stones), uric acid/urate stones for 9.6%, calcium phosphate stones for 5.1%, and struvite stones for 3.7%. The other 41.6% of the stones consisted of calcium oxalate mixed with other components. The male-to-female ratio was 2.7:1. CONCLUSION: In our series, calcium oxalate stones accounted for 81.6% of the urinary tract calculi, while uric acid/urate stones accounted for 15.8%. Uric acid stones, predominantly the anhydrous and/or dihydrate forms, showed a relatively high prevalence. Calcium oxalate stones, predominantly in the form of whewellite, showed a high prevalence among pure calculi; while the predominant combinations among mixed calculi were weddellite + calcium phosphate and whewellite + uric acid/urate.