Magnesium Ammonium Phosphate Stones Research Articles

Composition analysis of 1,495 cases of upper urinary tract calculi: the role of age and gender.

This study aimed to quantitatively analyze the calculi components of upper urinary tract calculi and to explore the relationship between calculus components, demographic characteristics, and underlying diseases. Clinical data of 1,495 patients with upper urinary tract calculi were retrospectively collected. The calculi were divided into simple calcium oxalate, calcium oxalate mixed, calcium phosphate mixed, uric acid, magnesium ammonium phosphate, and other components. Statistical software SPSS 22.0 was used to analyze the differences between the stone compositions and various factors. The influencing factors (p < 0.05) were analyzed using multiple logistic regression analysis. Among 1,495 patients with upper urinary tract calculi, simple calcium oxalate calculi were the most common component (39.7%), followed by calcium oxalate mixed calculi (30.4%), uric acid calculi (13.6%), calcium phosphate mixed calculi (10.4%), magnesium ammonium phosphate calculi (5.8%) and other component calculi (0.1%). Univariate analysis revealed statistically significant differences in stone composition according to gender, age, and hyperuricemia (p < 0.05). Multiple logistic regression analysis showed that compared to men, the odds ratio (OR) values of calcium oxalate mixed stones, calcium phosphate mixed stones, and magnesium ammonium phosphate stones in women were 1.61, 2.50, and 4.17, respectively (p < 0.001). Compared with elderly patients, the OR values of calcium phosphate mixed stones in young and middle-aged patients were 3.14 and 2.70, respectively (p < 0.05). Patients with different stone components had different demographic characteristics, and stone components were significantly different between gender and age. Calcium oxalate mixed stones were more common in females, and calcium phosphate mixed stones and magnesium ammonium phosphate stones were more common in females, young patients, and middle-aged patients.

Composition analysis of renal and ureteral calculi in a single center in northern China in the past decade.

The current report aimed to evaluate the characteristics of stone composition in 3637 renal and ureteral calculi patients in a single center while clarifying its relationship with sex, age, and time. Out of 3637 cases of upper urinary tract stones, stone specimens were analyzed retrospectively. There were 2373 male patients aged 6 months-87 years, with an average age of 44.73 ± 15.63 years, and 1264 female patients aged 4 months-87 years, with an average age of 46.84 ± 16.00 years. The male-female ratio was 1.88:1. Five hundred twelve patients had ureteral calculi, and 3125 had renal calculi. The SPSS software helped analyze the relationship between renal and ureteral calculi composition and sex, age, and time. Stone composition demonstrated 2205 cases of calcium oxalate stones (60.6%), 518 carbonate apatite (14.2%), 386 uric acids (10.6%), 232 magnesium ammonium phosphate (6.4%), 117 calcium phosphate (3.2%), 76 cystine (2.1%), 47 sodium urate (1.3%), 31 others (0.9%), and 25 ammonium urate (0.7%) cases. The overall male-to-female sex ratio was 1.88:1. Stones in the upper urinary tract were significantly more frequent in men than in women between the ages of 31 and 60. However, such stones were significantly more frequent in women than men over 80 (P < .05). Cystine, Sodium urate, Carbonated apatite, and uric acid indicated significant differences between different age categories (all P < .001). Stone composition analyses revealed that the frequency of calcium oxalate calculi has increased annually, while cystine and carbonated apatite incidences have dropped annually over the past decade. The components of renal and ureteral calculi vary significantly based on age and sex, with calcium oxalate calculi being more frequent in men while magnesium ammonium phosphate stones are more frequent in female patients. The age between 31 and 60 years is the most prevalent for renal and ureteral calculi in men and women.

Do Infection-Associated Stone Subtypes Behave the Same Clinically? A Retrospective Bicenter Study.

Introduction and Objectives: Infection-associated renal stones are commonly composed of magnesium-ammonium-phosphate (MAP) and carbonate apatite (CA). The clinical implications of these two different, but closely related stone types, are unknown. We sought to compare the clinical, microbiologic, and metabolic characteristics of patients with MAP and CA stone types. Methods: We retrospectively reviewed the medical records of patients from two centers (one in the United States and one in Israel) who underwent ureteroscopy or percutaneous nephrolithotomy between 2012 and 2020 and identified patients with a predominant stone analysis component of CA or MAP and clinical data supporting an infection stone. We analyzed and compared demographic data, medical history, postoperative fever, stone and urinary microbiology, and 24-hour urine studies. Results: A total of 79 and 75 patients met the inclusion criteria for the MAP and CA cohorts, respectively. No significant difference was found in patient demographics or comorbidities between the MAP and CA cohort. Female predominance was noted in both. Although there were no significant differences in 24-hour urine parameters between the cohorts, hypercalciuria was common in both cohorts (38% and 32% of patients in the MAP and CA cohorts, respectively). Gram-negative bacteria were more common in the MAP stone cultures. Postoperative fever was significantly more common in the MAP cohort (14.7% vs 3.8%, p < 0.016). Conclusions: MAP and CA stone formers share similar demographic characteristics with a clear female predominance. MAP stones patients appear more likely to develop postoperative fever, possibly related to a higher occurrence of gram-negative bacteria in the stone cultures of the MAP cohort. Although there were no significant differences among metabolic parameters, hypercalciuria was noted in approximately a third of the cohort. The clinical significance of this finding is yet to be determined.

Trends in urinary stone composition in 23,182 stone analyses from 2011 to 2019: a high-volume center study in China.

To evaluate the distribution and dynamic trends in constituents of urinary stones in China. The composition of 23,182 stones were analyzed and then recorded between January 2011 and December 2019. The characteristics in terms of stone patient's gender, age and calendar year were analyzed. Most stones (22,172,95.64%) had several crystal components, among which 40.25% (8925/22,172) were mixtures with infection components. Calcium oxalate (CaOx) and uric acid (UA) stones were more commonly encountered in men, but calcium phosphate (CaP), magnesium ammonium phosphate (MAP) and carbonate apatite (CA) stones were more prevalent in women (p < 0.05). In males, the proportion of CaOx stones increased up to the age of 40, but subsequently decreased (p < 0.001). Interestingly, females showed an inverse trend regarding CaOx stones (p < 0.001). The proportion of UA stones increased with age (p < 0.001), and CA stones most frequently were recorded at age 20-49. Over the past 9years, UA, CA, and MAP stones increased over time, whereas there was a tendency for CaOx stones to decrease (p < 0.05). The scarcity of pure stones and a certain proportion of mixtures with infection stone components (e.g., mixtures of CaOx and CA) suggest that treatment directed against a single stone component is insufficient for effective recurrence prevention. Age and gender were significant determinants of stone composition, and according to the observed chronological trends, it seems that in the future, more UA, CA and MAP stones and fewer CaOx stones may be encountered in the studied population.

Metabolic assessment in pure struvite stones formers: is it necessary?

Background and objective: Magnesium ammonium phosphate stones (MAP), also known as struvite stones, are associated with urinary infection and impairment of renal unit. The aim of this study is to evaluate the urinary metabolic risk factors for recurrence of renal calculi in patients submitted to nephrectomy due to MAP stones.Methods: We retrospectively reviewed the charts of patients > 18 years old submitted to total nephrectomy due to pure MAP stones and pure calcium oxalate (CaOx) stones from July 2006 to July 2016. Urinary metabolic parameters were assessed through 24-hour urine exams ≥ 3 months after nephrectomy. Urinary metabolic parameters and new event related to lithiasis were compared.Results: Twenty-eight and 39 patients were included in MAP and CaOx group, respectively. Abnormalities in 24-hour urine samples were similar between groups. Hypercalciuria occurred in 7.1 and 10.3% of patients in MAP and CaOx group, respectively (p = 0.66), whereas hypocitraturia was present in 65.2 and 59.0% of patients with MAP and CaOx group, respectively (p = 0.41). No significant difference in new events was found between MAP and CaOx groups (17.9 vs. 23.1%, respectively; p = 0.60).Conclusion: A 24-hour urine evaluation should be offered to patients submitted to nephrectomy due to pure MAP stones in order to detect metabolic risk, improve treatment, and prevent stone recurrence.

Urinary stone composition analysis of 4 423 cases in Zhejiang province

Objective To study the constituents of urinary stones in patients in Zhejiang, and analyze the composition difference between patients from northern Zhejiang province and southern Zhejiang province. Methods From October 2012 to October 2018, clinical data of 4 423 urinary stone patients treated in Sir Run Run Shaw Hospital, the Second Affiliated Hospital of Wenzhou Medical University, and Huzhou First People's Hospital was retrospectively analyzed. Infrared spectrum was used to analyze urinary calculi constituents. Among 4 423 patients, there were 3 041 males and 1 382 females, male to female ratio was 2.2∶1, and the mean age was (51.2±16.5) years. There were 2 974 northern Zhejiang patients and 1 449 southern Zhejiang patients. High incidence age group was 41- 60 years[48.2%(2 136/4 423)]. The distribution characteristics of urinary calculi constituents in different groups of sex, age, and region were analyzed. Results Among the 4 423 cases, the mixed urinary stones were dominant in the urinary calculus [73.1%(3 235/4 423)], in which, the most component was the calcium oxalate monohydrate+ calcium oxalate dehydrate+ carbonated apatite [36.2%(1 604/4 423)]; among the pure stones, the most component was the calcium oxalate monohydrate[16.3%(719/4 423)]. Carbonated apatite stones [70.1%(970/1 382) vs. 61.0%(1 856/3 041), P 60 years group, however, uric acid stones were more frequent in >60 years group [3.5%(38/1 060) vs. 17.0%(209/1 227), P<0.05]. The proportion of calcium oxalate stones in southern Zhejiang was lower than northern Zhejiang [79.0%(1 145/1 449) vs. 89.4%(2 661/2 974), P<0.05]. However, carbonated apatite stones [71.5%(1 037/1 449) vs. 60.1%(1 789/2 974), P<0.05], magnesium ammonium phosphate stones [15.1%(220/1 449) vs. 3.5%(106/2 974), P<0.05], and uric acid stones [10.7%(156/1 449) vs. 8.4%(250/2 974), P<0.05] were more prevalent in southern Zhejiang than northern Zhejiang. Conclusions The distribution of constituents of urinary stones in Zhejiang was different in genders, age, and regions. Carbonated apatite stones and magnesium ammonium phosphate stones were more prevalent in females and young people, and uric acid stones were more common in males and old people. Calcium oxalate stones were more common in youths. Moreover, calcium oxalate stones were more frequent in northern Zhejiang, and carbonated apatite stones, magnesium ammonium phosphate stones and uric acid stones were common in southern Zhejiang. Key words: Urinary calculi; Analysis of constituents; Gender; Age; Region

The systematic classification of urinary stones combine-using FTIR and SEM-EDAX

BackgroundTo explore underlying mechanism of urinary stones formation, the composition and microstructure of urinary stones were analyzed systematically with a large sample study from China. Materials and methodsA total of 2437 urinary stones were obtained from the urology department at our Hospital. The composition of the stones was analyzed by Fourier transform infrared spectroscopy (FTIR). Meanwhile, the microstructure and element distribution were observed with scanning electron microscopy combined with element distribution analysis (SEM-EDAX). ResultsUrinary stones were classified into eight types, that were consisted of calcium oxalate stones (1301/2437, 53.39%), calcium phosphate stones (131/2437, 5.38%), anhydrous uric acid stones (434/2437, 17.81%), magnesium ammonium phosphate stones (12/2437, 0.49%), sodium urate stones (5/2437, 0.21%), brushite stones (4/2437, 0.16%), cystine stones (3/2437, 0.12%) and mixed stones (547/2437, 22.45%, ten subtypes were included). Under SEM, they displayed distinct microstructures: plank-like, brick-like, polyhedron or paliform crystals for calcium oxalate stones, similar sized echin-sphere or rough bulbiform or tree bark-like crystals for calcium phosphate stones, rotten-wood-like or petrous crystals for anhydrous uric acid stones, globular or gallet-like crystals for magnesium ammonium phosphate stones, sawdust-like crystals for sodium urate stones, broken-wood-like crystals for brushite stones, stacking hexagonal cystine crystals for cystine stones, and two or more of the above crystals for mixed stones. Meanwhile, they also presented distinct elemental composition and distribution by EDAX. ConclusionsUrinary stones can be classified into eight types, and exhibit a diversity of microstructure and elemental compositions in China. The formation process of different types of urinary stones may be diverse.

Multivariate Analyses of Urinary Calculi Composition: A 13-Year Single-Center Study.

The incidence and prevalence of urinary stone are increasing throughout the world. Compared to the past, recent demographics of patient with urolithiasis compositions are strikingly different. Furthermore, recent clinical studies implied that seasonal cyclicity might influence the distribution of stone composition. We sought to determine the trends in pathogenesis of urolithiasis based on urinary stone analyses. Between 2002 and 2014, a total of 2,383 eligible urinary stone samples from different patients were collected in our center. Infrared spectroscopy was used for urinary calculi analysis. A logistic regression analysis was used to investigate the relationship between urinary calculi composition and calendar month (season), gender, and age in north China during the past 13 years. Calcium-containing calculi were the most frequent with an overall incidence of 84.1%. Calcium phosphate (CaP) or magnesium ammonium phosphate (MAP) stones were more frequent in females, while monohydrate calcium oxalate (COM), dihydrate calcium oxalate (COD), or uric acid (UA) stones were more common in males. Older individuals were associated with an increased risk of UA stones and a decreased risk of COD, CaP, or cystine stones. Additionally, from 2002 to 2014, the frequency of COD and MAP stone increased, whereas the trend of CaP, UA and cystine stones decreased. However, calendar month (season) was not significantly associated with differences in composition. This study provides the present distribution of urolithiasis compositions in China. From 2002 to 2014, age and gender were significantly associated with stone composition, whereas calendar month was not.

Formation Mechanism of Magnesium Ammonium Phosphate Stones: A Component Analysis of Urinary Nanocrystallites

The components of urinary nanocrystallites in patients with magnesium ammonium phosphate (MAP) stones were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectrometer, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), fast Fourier transformation (FFT), and energy-dispersive X-ray spectroscopy (EDS). The main components of the stones were MAP hexahydrate (MAP·6H2O), magnesium hydrogen phosphate trihydrate (MgHPO4·3H2O), and a small amount of calcium phosphate (CaP), while the main components of urinary nanocrystallites were MgHPO4·3H2O, CaP, and MAP monohydrate (MAP·H2O). MAP·H2O induced the formation of MAP stones as seed crystals. MgHPO4·3H2O was accompanied by the appearance of MAP·6H2O. The formation mechanism of MAP stones and influencing factors were discussed on the basis of the components of urine nanocrystallites. A model diagram of MAP stone formation was also put forward based on the results. Formation of MAP stones was closely related to the presence of high amounts of MAP crystallites in urine. Urinary crystallite condition and changes in urine components could indicate the activity of stone diseases.

Correlation between urinary stones and urinary tract infections

To explore the correlation of urinary stones and urinary tract infections. 300 cases with urinary tract stones received in our hospital from Feb. 2010 to Oct. 2013 were chosen as study samples. Urine routine index, situation of urine positivity and urinary tract infection after surgery were analyzed while, intraoperative cotton swabs were tested after being dipped in liquid near stones. Main components of stones in non-infected and infected stone group were analyzed and compared. Data on urolithiasis was collected. 96 infected stones were found in 300 patients, accounting for 32%, which including 35 cases of E. coli (36.5%), 28 cases of Staphylococcus epidermidis (29.2%), and 15 cases of Proteus mirabilis (15.6%). Numbers of urine abnormalities, urine positivities, positive intraoperative cotton swabs and urinary tract infections in patients in the group with infected stones, were significantly higher than in the group without infected stones and the differences were statistically significant (χ² = 8.203, 73.99, 178.9, 24.26, P < 0.05). The incidence rates of hexahydrate magnesium ammonium phosphate, carbonate apatite and hydroxyapatite stones in the group with infected stones were significantly higher than those in the non-infected-rock group while the incidence rates of calcium oxalate and uric acid stones were found significantly lower than those in the non-infected-stone group, with differences statistically significant (χ² = 167.6, 21.00, 8.586, 73.17, 48.79, P < 0.05). Bacteria could cause urinary tract stones, and infected stones were always associated with urinary tract infections. Bacteria detection in patients with urinary calculi was particularly important to avoid the urinary tract infections.

Urinary stone analysis on 12,846 patients: a report from a single center in China

We reported a retrospective review of the urinary stone compositions in 12,846 patients. Data on urinary stone compositions analyzed between January 2003 and December 2012 in our center were collected. Infrared spectroscopy was used for stone analysis. Predominant stone component was recorded. Patients were divided into four age groups: 0-18, 19-40, 41-60, and 61-92, and five categories by components. In order to determine the change of stone characteristics with respect to time, data were also divided into two periods, 2003-2007 and 2008-2012. A total of 12,846 stones were included in this study. The age of the patients ranged from 1 to 92 years with 7,736 males and 5,110 females. Stone made of single component was rare, 2.61%. Calcium oxalate stone was the most common component at 82.56%. Calcium oxalate and uric acid stones were more common in male than in female. The incidence of calcium phosphate stones and uric acid stones had increased during the past 5 years, while calcium oxalate stones decreased. We found the highest incidence of stone disease in the 41-60 years old group and the lowest in the 1-18 years old for both genders. Calcium oxalate was the dominant component in every group but was more prevalent in 19-40 years group. The percentage of magnesium ammonium phosphate stone and uric acid stone increased with age.

A giant bladder struvite stone in an adolescent boy

A 14-year-old adolescent boy with a history of recurrent lower urinary tract infection presented with a complaint of lower abdominal pain. Renal ultrasonography revealed bilateral hydronephrosis and X-ray film revealed a huge pelvic mass measuring 10 × 8 × 6 cm which filled the whole bladder. Open cystolithotomy was performed and magnesium ammonium phosphate (struvite) stone weighing 420 g was removed. Although a bladder stone is not rare, in the present report, the composition and the huge size of the stone determined in an adolescent patient is an interesting clinical entity. To the best of our knowledge, this is the largest struvite stone reported in an adolescent patient.

Lithogenic activity and clinical relevance of lipids extracted from urines and stones of nephrolithiasis patients

We investigated contents and classes of urinary and stone matrix lipids, and evaluated their clinical relevance in nephrolithiasis patients. Lithogenic role of major lipid classes was explored. Urine (24 h) and stone samples were collected from 47 patients with nephrolithiasis. Control urines were obtained from 29 healthy subjects. Urinary 8-hydroxy-deoxyguanosine (8-OHdG), malondialdehyde (MDA), N-acetyl-β-glucosaminidase (NAG) activity and total proteins were measured. Total lipids were extracted from centrifuged urines (10,000 rpm, 30 min) and stones by chloroform/methanol method. Major classes of lipids were identified using multi-one-dimensional thin-layer chromatography (MOD-TLC). Influence of each lipid class purified from stone matrices on stone formation was evaluated using crystallization and crystal aggregation assays. Urinary NAG activity and 8-OHdG were significantly elevated in nephrolithiasis patients. Total lipids in centrifuged urines of the patients were not significantly different from that of controls. In nephrolithiasis, urinary excretion of total lipids was linearly correlated to urinary MDA, 8-OHdG, NAG activity and total proteins. Lipid contents in stone matrices varied among stone types. Uric acid stone contained lower amount of total lipids than calcium oxalate and magnesium ammonium phosphate stones. MOD-TLC lipid chromatograms of healthy urines, nephrolithiasis urines and stone matrices were obviously different. Triacylglyceride was abundant in urines, but scarcely found in stone matrices. Stone matrices were rich in glycolipids and high-polar lipids (phospholipids/gangliosides). Partially purified glycolipids significantly induced crystal aggregation while cholesterol was a significant inducer of both crystal formation and agglomeration. In conclusion, total lipids in centrifuged urines did not differ between nephrolithiasis and healthy subjects. Our finding suggests that the significant sources of lipids in patients' urine may be large lipids-containing particles, which are removed in centrifuged urines. However, urinary lipid excretion in nephrolithiasis patients was associated with the extent of oxidative stress and renal tubular injury. Triacylglyceride was abundant in urines, but rarely incorporated into stones. Glycolipids were principal lipid constituents in stone matrices and functioned as crystal aggregator. Cholesterol purified from stone matrices bared crystal nucleating and aggregating activities.

Plasma levels and urinary excretion of amino acids by subjects with renal calculi

Plasma levels and urinary amino acid excretions were estimated by high-performance liquid chromatography in 15 control subjects and 36 stone formers (SFs) classified according to the stone type: (1) 22 cases with calcium oxalate stones; (2) four cases with pure uric acid stones; (3) 10 cases with magnesium-ammonium phosphate stones, either pure or mixed with apatite. Some types of stones (namely oxalate and uric acid calculi) are mainly formed as a result of a metabolic deficiency that may affect the amino acid metabolism, and thus may be reflected in the urinary amino acid pattern. Data demonstrated clearly that there is a general tendency towards decreased amino acid excretions in all SFs with all types of stones. As a whole, one can observe a higher percentage of patients with calcium oxalate and phosphate calculosis, who have low urine excretions of amino acids; about 50% are the SFs with lower urine excretion of serine, glycine, taurine and i-leucine; the high percentage of patients with CaOX calculi shows lower urine excretions of tyrosine and ornithine.

Urinary Stone Analysis of 1,000 Patients in Southern Taiwan

Urolithiasis is a common urologic disease. Stones may occur in the kidney, ureter, or urinary bladder. We collected 1,000 stone samples in the subtropical area of southern Taiwan. Stone components were analyzed by Fourier transform infrared spectroscopy. Mixed components of calcium oxalate and calcium phosphate were the most common form of stones (52.3%), followed by calcium oxalate (27.8%) and calcium phosphate (9.3%). Uric acid stones accounted for 7.6%. Magnesium ammonium phosphate stones accounted for 3.0%. Only one cystine stone was found. In the study of urinary stone formation mechanism and prevention of recurrent urolithiasis, knowing the stone composition is important.

Composition and clinically determined hardness of urinary tract stones

To derive hardness factors for crystal phases of urinary tract stones and describe the hardness pattern in a stone population. In a retrospective study, recordings from patients treated with extracorporeal shock-wave lithotripsy (ESWL) (stone surface area < or = 100 mm2) were used to derive hardness factors. The number of re-treatments, the number of shock waves and the energy index (the voltage in kilovolts multiplied by the number of shock waves) required for a satisfactory stone disintegration were assumed to reflect the hardness. The stone composition in 2100 patients provided the basis for an average hardness pattern. A hardness index was calculated from the fraction of each crystal phase and its hardness factor. The hardness factors were as follows: calcium oxalate monohydrate, 1.3; calcium oxalate dehydrate, 1.0; hydroxyapatite, 1.1; brushite, 2.2; uric acid/urate, 1.0; cystine, 2.4; carbonate apatite, 1.3; magnesium ammonium phosphate, 1.0; and mixed infection stones, 1.0. The hardness index for 114 stones (surface area 100-200 mm2) corresponded reasonably well to the ESWL treatment efforts. Calcium oxalate monohydrate, calcium oxalate dihydrate and hydroxyapatite were the most frequently encountered crystal phases in all 2100 stones. Only 21% of the stones were composed of only one crystal phase. There were two, three and more than three crystal phases in 26%, 38% and 15% of the stones, respectively. The hardness index calculated for 2100 stones ranged between 0.70 and 2.33, with a mean (SD) of 1.18 (0.15). The hardness factors and hardness index derived in this study might be useful for describing the stone situation in individual patients and groups of patients and for comparison of various treatment strategies.

Annual changes of the incidence and clinical characteristics of magnesium ammonium phosphate urinary stones.

Magnesium ammonium phosphate (MAP) urinary stones account for the majority of staghorn stones and frequently cause a non-functioning kidney. In the present study, we examined the annual changes of the number and clinical characteristics of MAP stones. The annual incidence of MAP stones was investigated in 2619 patients with urinary stones in whom composition of the stone was analysed at Chiba University Hospital between 1964 and 1999. In addition, the annual number of patients with MAP stones was examined at Funabashi Clinic. In a total of 644 patients with MAP stones, age and sex of the patients, location and size of the MAP stones, urinary cultures and etiological factors were analysed. The number of MAP stones in the lower urinary tract was relatively constant. In contrast, MAP stones in the upper urinary tract had dramatically decreased since 1989, resulting in an increase in the rate of MAP stones in the lower urinary tract. Age distribution of the MAP stone patients ranged from 10 years to > 80 years, with the majority aged 30-60 years. The proportion of larger MAP stones in the upper urinary tract increased. There was no significant difference in prevalence of urine cultures. Among etiological factors for MAP stones, difficulty on urination tended to be common in recent years. The number of MAP stones, especially in upper urinary tract, has been decreasing during the last decade. At present, treatment of urinary tract obstruction seems important for the management of MAP stones in lower urinary tract.

MICROBIAL AND BIOCHEMICAL ABNORMALITIES IN PATIENTS WITH STRUVITE - STONES

The present study was carried to find out the role of bacteria in struvite stone formation and the associated biochemical abnormalities in the serum of patients. Thus, 16 struvite stone-formers were categorized into two groups according to the presence or absence of uric acid in the chemical composition of struvite stones. The changes in serum protein and glycoprotein were examined. Isolation and identification of bacteria were carried out for urine and the surface of the stone samples. It was noticed that the high level of α 2-, B-glycoprotein in serum may reflect acute bacterial infection and a sort of inflammation in many cases of the studied groups compared to 17 healthy normal persones. Surgically removed struvite stones were infected with urea-splitting bacteria especially Proteus mirabilis which was found in many samples ( 42.9%) of both urine and stones of patients with Calcium oxalate, Calcium phosphate, Magnesium ammonium phosphate and uric acid stones. This could be explained by the fact that the organism had been participating in the fomation of struvite stones. In some cases with struvite stones, associated with chronic urinary tract infection mixed bacteria (more than one organism) were commonly detected in urine samples.

Evaluation of Homonia riparia Lour. for Antiurolithiatic Activity in Albino Rats

Ethanol extract of the roots of Homonia riparia was tested for its antiurolithiatic activity against calcium oxalate and magnesium ammonium phosphate stones in male albino rats. Calcium oxalate stones were induced by feeding 3% glycolic acid along with normal feed and magnesium ammonium phosphate stones were induced by implantation of zinc discs in the urinary bladder. The ethanol extract of H. riparia (2 g/kg/day, orally) was found to be effective in reducing deposition of calcium in the kidney of both prophylactic and curative group animals. The extract did not show any significant effect on the activity of the liver enzyme glycolic acid oxidase and on the deposition of oxalate in the kidney. The extract was found to be effective in reducing the formation and also in dissolving the pre-formed magnesium ammonium phosphate type of stones.

Chemical Compositions of 300 Lower Urinary Tract Calculi and Associated Disorders in the Urinary Tract

The stones removed from 273 patients (220 males, 53 females) with bladder stones and 27 patients with urethral stones (males) were analyzed by infrared spectroscopy. Of these stones 50.0% contained magnesium ammonium phosphate (MAP), 39.9% calcium (oxalate and/or phosphate), 9.4% uric acid (urate), and 0.7% cystine. The disorders associated with bladder stones were prostatic hyperplasia and cancer (47.8%), neurogenic bladder (11.8%), urethral stricture (3.6%) and so on in males, and neurogenic bladder (48.1%), after operation of uterus (29.0%), bladder cancer (5.7%) and so on in females. Urinary infections were complications in 59.3% of patients with MAP stones, 41.2% with urate stones and 20.0% with calcium stones. The most often isolated bacteria from the infected urine were of the Proteus species.