Mesalazine: A Novel Etiology For Drug-Induced Urinary Calculi

We report the case of a 23-year-old woman treated by mesalazine for ulcerative colitis and who subsequently presented recurrent renal colic due to mesalazine urinary stones. This is the second case described in the literature.Mesalazine stones are soft, friable and have an orange-beige color. They are not visible on non-contrast computed tomography (CT). Their diagnosis is based on morpho-constitutional analysis and CT-urography. Patients treatedby mesalazine who present renal colic should undergo CT-urography in order to make the diagnosis.

[Pyonephrosis due to xanthine stones in a bitch treated with allopurinol]

A 2-year-old, neutered, crossbreed bitch was presented as an emergency with painful abdomen, fever and vomiting. The cause of the acute abdomen was a pyonephrosis of the left kidney, caused by four xanthine stones, which had blocked the ureter. After surgical removal of the heavily altered left kidney, the bitch recovered rapidly. Because of a leishmaniasis the bitch had been treated with allopurinol over an extended period, the xanthine stone formation is likely to have resulted from allopurinol usage. Because there were additionally small concrements in the right kidney, the medication was stopped. Subsequently, the dog has received a low purine diet, and the leishmaniasis titer and renal function have been monitored regularly.

[Clinical analysis of 41 children's urinary calculus and acute renal failure]

OBJECTIVE

To analyze the treatment of acute renal failure caused by irrational drug use.

METHOD

Data of 41 cases of acute renal failure seen from July 2008 to June 2012 in our hospital were reviewed. Bilateral renal parenchymas diffuse echo was found enhanced by ultrasound in all cases. Calculus image was not found by X-ray. All children had medical history of using cephalosporins or others. Alkalinization of urine and antispasmodic treatment were given to all children immediately, 17 children were treated with hemodialysis and 4 children accepted intraureteral cannula placement.

RESULT

In 24 children who accepted alkalinization of urine and antispasmodic treatment micturition could be restored within 24 hours, in 11 children micturition recovered after only one hemodialysis treatment and 2 children gradually restored micturition after hemodialysis twice, 4 children who accepted intraureteral cannula immediately restored micturition. In all children micturition recovered gradually after a week of treatment. Ultrasound examination showed that 39 children's calculus disappeared totally and renal parenchymas echo recovered to normal. The residual calculi with diameter less than 5 mm were found in 2 children, but they had no symptoms. The children received potassium sodium hydrogen citrate granules per os and were discharged from hospital. Ultrasound showed calculus disappeared totally one month later.

CONCLUSION

Irrational drug use can cause children urolithiasis combined with acute renal failure, while renal dysfunction can reverse by drug withdrawal and early alkalinization of urine, antispasmodic treatment, intraureteral cannula or hemodialysis when necessary, most calculus can be expelled after micturition recovered to normal.

Health risks and benefits from calcium and vitamin D supplementation: Women's Health Initiative clinical trial and cohort study

SUMMARY

The Women's Health Initiative (WHI) double-blind, placebo-controlled clinical trial randomly assigned 36,282 postmenopausal women in the U.S. to 1,000 mg elemental calcium carbonate plus 400 IU of vitamin D(3) daily or placebo, with average intervention period of 7.0 years. The trial was designed to test whether calcium plus vitamin D supplementation in a population in which the use of these supplements was widespread would reduce hip fracture, and secondarily, total fracture and colorectal cancer.

INTRODUCTION

This study further examines the health benefits and risks of calcium and vitamin D supplementation using WHI data, with emphasis on fractures, cardiovascular disease, cancer, and total mortality.

METHODS

WHI calcium and vitamin D randomized clinical trial (CT) data through the end of the intervention period were further analyzed with emphasis on treatment effects in relation to duration of supplementation, and these data were contrasted and combined with corresponding data from the WHI prospective observational study (OS).

RESULTS

Among women not taking personal calcium or vitamin D supplements at baseline, the hazard ratio [HR] for hip fracture occurrence in the CT following 5 or more years of calcium and vitamin D supplementation versus placebo was 0.62 (95 % confidence interval (CI), 0.38-1.00). In combined analyses of CT and OS data, the corresponding HR was 0.65 (95 % CI, 0.44-0.98). Supplementation effects were not apparent on the risks of myocardial infarction, coronary heart disease, total heart disease, stroke, overall cardiovascular disease, colorectal cancer, or total mortality, while evidence for a reduction in breast cancer risk and total invasive cancer risk among calcium plus vitamin D users was only suggestive.

CONCLUSION

Though based primarily on a subset analysis, long-term use of calcium and vitamin D appears to confer a reduction that may be substantial in the risk of hip fracture among postmenopausal women. Other health benefits and risks of supplementation at doses considered, including an elevation in urinary tract stone formation, appear to be modest and approximately balanced.

[Comparative efficacy of nitrofurans in children and adolescents with pyelonephritis in presence of crystalluria]

AIM

To evaluate the efficacy of nitrofurans in children and adolescents with pyelonephritis in the presence of crystalluria.

SUBJECTS AND METHODS

The study included 50 patients aged 4-14 years with chronic pyelonephritis in the presence of dysmetabolism. The patients underwent general blood test, general urinalysis with an urocytogram, bacteriological examination of urine, biochemical test of serum (uric acid, calcium, phosphorus, magnesium, urea, and creatinine) and 24-hour urinary excretion (uric acid, oxalates, calcium, phosphorus, and magnesium) at hospital admission and over time. The treatment regimen for Group 1 patients after antibiotic therapy involved furamag, Group 2 received furagin. The drugs were used in a dosage of 2 mg/kg/day in 2 divided doses for 14 days. Complaints, major clinical manifestations, crystalluria patterns, and a number of laboratory findings were analyzed over time.

RESULTS

The urinary sediment showed leukocyturia and bacteriuria in all the patients, oxaluria in 70% of the patients, uraturia in 10%, and mixed crystalluria in 20%. The main etiological agent of pyelonephritis was Escherichia coli (48.4%). Increased serum uric acid concentrations were revealed in 14% of the patients. Daily urine tests revealed hyperoxaluria, hyperuricosuria, and hypercalciuria in 86, 18, and 8% of the patients, respectively; urinary magnesium excretion was reduced in 86%. After treatment, Group 1 patients showed a more marked therapeutic effect in terms of a number of indicators (leukocyturia, crystalluria, uricosuria, magnesuria).

CONCLUSION

The results of the study showed that the antibacterial therapy involving antibiotics and nitrofurans for an exacerbation of chronic pyelonephritis in the presence of crystalluria not only provides an anti-inflammatory effect, but also leads to reductions in the level of crystalluria and the urinary content of uric acid and calcium. There was a significantly marked reduction in crystalluria, serum uric acid, and urinary oxalates and calcium in the children taking furamag. Out of nitrofurans, furamag may be recommended as the drug of choice to treat urinary tract infections in the presence of crystalluria.

[Determination of melamine by high-performance liquid chromatography-mass spectrometry in urinary calculi]

OBJECTIVE

To establish a high-performance liquid chromatography-mass spectrometry (LC/MS)-based method for efficient determination of melamine in urinary calculi in children taking melamine-contaminated formula milk powder.

METHODS

LC/MS was employed to determine the contents of melamine in urinary calculi surgically removed from 17 children with a history of taking melamine-contaminated milk powder and in 4 samples of uric acid stone from adults. The positive ionization mode of electro-spray ionization source was used, and the limit of melamine determination was 0.1 mg/kg.

RESULTS

No melamine was detected in the 4 uric acid stone samples from adults. Melamine was detected in 4 samples of urinary calculi from the 17 children, with the concentration ranging from 0.8 to 64 mg/lkg.

CONCLUSION

LC/MS is simple and effective for detecting melamine in urinary calculi, which is helpful to the treatment and follow-up.

[Clinical strategies for prevention of drug-induced urinary calculi]

Drug-induced urinary calculi, although they account for only 1-2% of urinary calculi, deserve consideration because most of them are preventable. In the drug-containing calculi resulting from the crystallization of a certain drug and its metabolites in the urine, stone analysis can identify the responsible drug. While, in the drug-induced metabolic calculi caused by interference with calcium, oxalate and purine metabolism, careful clinical inquiry is necessary to reveal involvement of a certain drug in stone formation. Better awareness of the possible drugs with lithogenic potential and close surveillance of patients on long-term treatment with these drugs are necessary. Especially, in patients with a history of urolithiaisis, prescription of lithogenic drugs deserve careful consideration.

[Pathological changes in rat model of urinary calculus induced by melamine]

OBJECTIVE

To investigate melamine-induced pathological changes in the kidney.

METHOD

Wistar rats were fed with a diet containing 0, 1% and 2% melamine for 15 weeks. After melamine feeding was stopped, various outcome measures were observed for 4 weeks.

RESULT

Rats fed with melamine showed reduced caloric intake, slower weight gain and impaired renal function. The blood urea nitrogen of group A and B [(13.23 ± 5.10) mmol/L and (18.30 ± 5.90) mmol/L, respectively] and serum creatinine levels of group B [(19.90 ± 2.90) mmol/L] were higher than that of group C [(8.23 ± 2.30) mmol/L and (10.04 ± 1.73) mmol/L](P < 0.01, respectively). Additionally, the kidney coefficients of group A and B were higher than that of group C (P < 0.01, respectively). Crystals, tubular ectasia and interstitial inflammation and fibrosis were found in the kidneys of melamine fed rats. Four weeks after discontinuation of feeding with melamine-contained diet, the caloric intake and weight of the rats increased, the coefficients of the kidney decreased, and the blood urea nitrogen of group A and B [(17.96 ± 2.04) mmol/L and (19.20 ± 3.36) mmol/L, respectively] and serum creatinine levels of group B [(24.20 ± 5.28) mmol/L], which became worse than 4 weeks before (P < 0.01;P < 0.05, respectively), and were still higher than that of group C [(8.30 ± 1.79) mmol/L and (9.87 ± 2.71) mmol/L, P < 0.01, respectively]. Crystals remained inside the kidney, changes in the renal interstitium did not improve.

CONCLUSION

(1) Melamine-induced urinary calculus rat model can be established by feeding 3-week old male Wistar rats with a diet containing 2% melamine for 15 weeks. The main constituent of the urinary calculus was melamine (> 90%), with a little uric acid and traces of cyanuric acid. (2) Melamine damaged the renal function, formed renal crystals, and led to the pathological changes of kidneys. All the influences seemed to be dose-depended and was related with the obstruction of the crystals or calculus in the kidney. (3) The renal function and the pathological changes did not improve 4 weeks after discontinuation of feeding with melamine-contained diet.

The characteristics of immune system changes in children who ingested melamine-contaminated powdered formula in China

Since 2008, the food safety issue of melamine poisoning has again become a health scare for children. The mechanism of how melamine initiates kidney stones and kidney-associated renal complications is still unknown. Some children who ingested melamine-contaminated powdered formula had leukocyturia, but none had typical symptoms of urinary tract infection. We believed that the children's immune systems might have some changes. We followed up 170 children who ingested melamine-contaminated powdered formula and tested their blood and urine and to observe their immune state, and also performed ultrasonography. In the immune responses of children with stones, immunoglobulin M takes a major immune response and the level of CD3(+), CD4(+) decreased compared with children without stones. There was no difference in complete blood count between the children with stones and those without stones. We concluded that leukocyturia had a certain relationship with non-urinary tract infectious renal disease and these children are susceptible to infectious diseases.

Therapeutic effects of potassium sodium hydrogen citrate on melamine-induced urinary calculi in China

BACKGROUND

In 2008, a sharp increase of the number of children diagnosed with urinary calculi was observed in China, 9433 children were diagnosed as having melamine-induced urinary calculi at outpatient clinic in Beijing Children's Hospital. This study examined the therapeutic efficacy of potassium sodium hydrogen citrate (PSHC) used to treat melamine-induced urinary stones in Chinese children who consumed melamine-containing infant formula.

METHODS

Seventy-two infants and children (average age (18.2 +/- 7.7) months) who were diagnosed with urinary calculi were randomly divided into three treatment groups using the SAS Plan program. Group 1 was given a low dose (1 g/d) of PSHC, group 2 was given high dose of PSHC (2 g/d) and group 3 was given no PSHC (control group). The dose of drug was adjusted according to the baseline urinary pH. This study analyzed the influence of the dose of PSHC, the age of patients, stone size and position, and urinary pH on the level of efficacy of PSHC (cured, effectively treated or not cured).

RESULTS

After 1 - 6 months of therapy, 19 patients from group 1, five patients from group 2 and six patients from group 3 were cured. Five patients from group 1, five patients from group 2 and four patients from group 3 were effectively treated. There were significant differences in therapeutic efficacy between the two treatment doses after 3 and 6 months as measured by the increase in the successful expulsion rate and time of melamine-induced urinary calculi. After 6 months the mean time of expulsion of urinary calculi in groups 1 and 2 was significantly shorter than in the control group.

CONCLUSIONS

PSHC can significantly increase the successful expulsion rate and time of melamine-induced urinary calculi. The therapeutic efficacy is affected by PSHC dose, treatment duration, calculi position, and urinary pH. There is no relationship between the therapeutic efficacy and the stone size or patient age.

[Follow-up study on children with urinary calculi associated with exposure to melamine-contaminated formula]

OBJECTIVE

To understand the prognosis of the children with urinary calculi associated with exposure to melamine-contaminated formula.

METHODS

A follow-up study was performed in 47 out-patients from the Third Hospital of Peking University who were diagnosed with urinary calculi associated with exposure to melamine-contaminated formula. Urinary tract B-ultrasound and renal function examinations were done during the 1 to 6-month follow-up.

RESULTS

By the 6th month of follow-up, spontaneous stone passage was found in 36 children (77%). The follow-up failed in four children. None of the patients had any complications. Spontaneous stone passage was not associated with the volume and the period exposed to melamine in formula, but was associated with the location of calculi. The time to spontaneous stone passage in boys appeared to be longer than in girls, but there were no statistical differences.

CONCLUSIONS

Spontaneous stone passage can be found in most children and the prognosis of children with urinary calculi associated with exposure to melamine-contaminated formula is good.

Cadmium-exposed population in Mae Sot district, Tak province: 3. Associations between urinary cadmium and renal dysfunction, hypertension, diabetes, and urinary stones

OBJECTIVE

To study the associations between urinary cadmium and renal dysfunction, hypertension, diabetes, and urinary stones in an adult population living in cadmium-contaminated areas in Mae Sot District, Tak Province, Thailand.

MATERIAL AND METHOD

Seven hundred ninety five cadmium-exposed adults were screened for urinary cadmium, renal dysfunction, hypertension, diabetes, and urinary stones in 2005. Six selected markers of renal function in the present study were urinary excretion of beta2-microglobulin (beta2-MG), N-acetyl-beta-D-glucosaminidase (NAG), total protein and calcium, serum creatinine, and glomerular filtration rate (GFR).

RESULTS

The mean age of the study persons was 50-years-old. The overall prevalence rates of hypertension, diabetes, and urinary stones were 33.3%, 6.2%, and 8.9% respectively. The prevalence of increased proteinuria was greatest in those with urinary cadmium levels > or = 15 microg/g creatinine. Urinary excretion of beta2-MG, NAG, and total protein significantly increased with increasing urinary cadmium levels, after adjusting for other co-variables by multiple linear regression analysis. However, urinary cadmium was not significantly associated with urinary calcium, serum creatinine, and GFR. The prevalence rates of hypertension, diabetes, and urinary stones did not significantly increase with increasing urinary cadmium levels. Hypertension, diabetes, and urinary stones were also significant predictors of impaired renal function.

CONCLUSION

In this population, increasing levels of urinary cadmium are associated with increasing urinary excretion of beta2-MG, NAG, and total protein. Risk for hypertension, diabetes, and urinary stones remains uncertain in relation to cadmium exposure.

Urogenital history in veterans exposed to high-dose sulfur mustard: a preliminary study of self-reported data

INTRODUCTION

To date, little information exists regarding urogenital diseases in those who have been exposed to sulfur mustard (SM). We report the self-reported history of urologic conditions and findings on physical examination in a group of male veterans 19 to 26 years after exposed to high-dose sulfur mustard.

MATERIALS AND METHODS

Data on urologic health conditions of a nationwide health survey were used in this study. This survey included all 289 Iranian male veterans who had been exposed to high doses of SM between 1983 and 1989. Demographic data, exposure-related data, health status, and also self-reported lifetime history of urologic conditions were analyzed. History of benign prostatic hyperplasia, recurrent urinary tract infections, pyelonephritis, urinary calculi, kidney failure, and urogenital neoplasms were specifically concerned.

RESULTS

The mean age of the veterans was 45.0 ? 7.5 years (range, 30 to 75 years). An interval of 19 to 26 years had passed from exposure to SM. Fifty veterans (17.3%) had a positive history of urinary calculi, 25 (8.7%) had recurrent urinary tract infections, 5 (1.7%) had BPH, and 2 (0.7%) had kidney failure. None of them had experienced urogenital malignancies. Neither recurrent urinary tract infections nor urinary calculi were significantly associated with age, medications and their doses, or SM-induced late complications in other organs.

CONCLUSION

This study adds the prevalence of self-reported urologic conditions to our limited knowledge on SM-exposed veterans' health condition, without finding any link neither to demographic, nor to the severity of health complications related to the SM exposure.

Evaluation of urinary oxalate levels in patients receiving gastrointestinal lipase inhibitor

OBJECTIVE

The purpose of this study was to examine the possible effects of a gastrointestinal lipase inhibitor "Orlistat (Xenical)" on the intestinal absorption of oxalate and thereby on the urinary levels of oxalate excretion in overweight patients.

METHODS AND PROCEDURES

Long-term follow-up data of 95 cases (57 men, 38 women; M/W=1.5) were documented. Patients were randomly assigned into two groups. While the patients in group I (n=55) were treated with orlistat (Xenical) for 6 months, patients in group II (n=40) received no specific medication. Calcium, oxalate, and citrate levels were determined in a 24-h urine collection from each patient. To evaluate the significance in the groups as well as the differences between the two groups, ANOVA test was performed and the results were given as mean +/- s.d.

RESULTS

Comparative evaluation of urinary oxalate levels during 3-month follow-up clearly showed that urinary oxalate excretion significantly increased in 34/55 patients (61.8%) in the first group (P<0.05). Of these 34 patients, 30 (88.2%) continued to have increased urinary oxalate excretion during 6-month follow-up (P=0.001). However, our data did not show any significant effect of this medication on urinary citrate and calcium levels during 3- and 6-month follow-up evaluation (P=0.05).

DISCUSSION

Our results suggest that increased intestinal absorption of dietary oxalate due to this type of medication in obese patients could make a substantial contribution to urinary oxalate excretion and may increase the risk of stone formation.

Induction of progressive profound hypocitraturia with increasing doses of topiramate

OBJECTIVES

To provide prospective, longitudinal evidence of the effects of topiramate, an antiepileptic medication prescribed for migraine headaches, on stone-risk factors, specifically as pertaining to dosing and rapidity of onset.

METHODS

Patients scheduled to begin topiramate therapy were recruited to participate in the study. Enrolled subjects collected a pretreatment 24-hour urine specimen with subsequent 24-hour urine specimens collected 5 days after beginning topiramate and after each dose escalation.

RESULTS

Six subjects enrolled in the study, 4 of whom completed two additional urine collections after initiating topiramate therapy. The pretreatment urine collections of the 4 subjects with additional samples revealed the following mean (range) values: urine volume 1550 (1300 to 1900) mL, pH 6.75 (6 to 7), creatinine 1436.3 (1196 to 1590) mg/day, calcium 305.8 (209 to 423) mg/day, and citrate 606.8 (290 to 860) mg/day. Five days after initiation of topiramate, mean calcium decreased to 211.5 mg/day (31% decrease), and mean citrate decreased to 398 (99 to 804) mg/day, an average decrease of 39.8% (6.5% to 65.9%) per patient. After a dose escalation, calcium increased to 286.8 mg/day, but citrate decreased further to 209 (119 to 353) mg/day, an average decrease of 65.1% (57.9% to 71.7%) per patient from pretreatment levels.

CONCLUSIONS

Topiramate therapy induces a profound decrease in urinary citrate levels, equivalent to the levels seen in distal renal tubular acidosis. Citrate levels decrease quickly after the start of topiramate therapy and continue to decrease with escalating doses.

Histopathology and histomorphometry of the urogenital tract in 15-month old male and female rats treated neonatally with SERMs and estrogens

In this study, two selective estrogen receptor modulators (SERMs), tamoxifen (TAM) and toremifene (TOR) or two estrogens, ethinylestradiol (EE) and diethylstilbestrol (DES) were administered to newborn male and female Sprague-Dawley rats (days 1-5) to investigate the occurrence of developmental abnormalities in the adulthood. The compounds were dosed (s.c.) at an equimolar dose of 24.9 micromol/kg. During the follow-up period, mortality occurred mainly in DES-treated male rats (3/4), associated with obstructive urinary calculi and suppurative renal inflammation in 2/3 rats. Similar lesions were not evident in other groups. At the age of 15 months, the animals were necropsied and organs were collected for histopathology and histomorphometry. Treatment-related abnormalities were restricted to the reproductive organs. Chronic prostatitis and epithelial abnormalities in the vas deferens were observed in all treatment groups. The columnar epithelium of vas deferens showed hyperplasia and development of subepithelial glandular structures resembling epididymal cysts reported in humans exposed in utero to DES. Testicular atrophy was observed especially in estrogen-treated rats. Mainly in SERM-treated female rats, the uterus showed luminal dilation or obstruction, loss of endometrial glands and myometrium disorganization including foci of muscular disruption. TOR-treated female rats showed polyp-like nodules (incidence 4/15) and a high incidence (9/15) of a simple cuboidal epithelium in cervical regions normally occupied by multilayered epithelia. In conclusion, the vas deferens is a main target organ following neonatal administration of SERMs and estrogens. In addition, female rats were significantly more susceptible to SERM treatment than to treatment with estrogens.

Efavirenz-induced urolithiasis

We describe the first case of efavirenz-induced urolithiasis in a 47-year-old HIV-positive patient. Urinary obstruction led to pyelonephritis and septic shock, requiring emergency ureteral catheterisation. The subsequent clinical course was favourable, allowing the patient's discharge on day 5. A 7 mm, radio-translucent, non-crystalline, beige stone was extracted during catheterisation. Stone analysis by Fourier transform infrared spectrometry, liquid chromatography and mass spectrometry revealed a stone composed of efavirenz (EFV) metabolites M4, M5, M8 (as described by Mutlib et al. in 1999) and approximately 50% of unspecified proteins. EFV is a non-nucleoside reverse transcriptase inhibitor introduced to European markets in 1999. It is principally metabolised by cytochrome P450 3A4 and 2B6. Of the dose, 14-34% is excreted in the urine, 1% as unchanged drug. The patient had been taking 600 mg EFV per day for 3 years. As EFV-induced urolithiasis has not been reported so far, we would like to draw the attention of the medical community to this potentially severe complication.

[Nephrolithiasis and topiramate]

INTRODUCTION

Topiramate (TPM) is a new antiepileptic drug whose multiple mechanisms of action justify both its broad therapeutic spectrum and its increasingly widespread use in childhood epilepsy. TPM acts as a carbonic anhydrase inhibitor and, although this does not affect its effectiveness as an antiepileptic, it does account for certain side effects such as nephrolithiasis. The frequency of nephrolithiasis secondary to TPM in childhood is unknown and we have only found reports of five cases in children.

CASE REPORTS

We describe two cases of medication-resistant infantile epilepsy--a 3-year-old female with Dravet's syndrome and a male aged 4.5 years with Lennox-Gastaut syndrome. In both cases the decision was made to introduce TPM as add-on therapy after a prolonged therapeutic programme; a high degree of effectiveness was achieved in both patients. Nevertheless, the two patients developed nephrolithiasis secondary to TPM, which in the second case was related to the simultaneous treatment with adrenocorticotropic hormone (ACTH), while no known favouring factor was found in the first patient.

CONCLUSIONS

We outline the physiopathogenic mechanism explaining nephrolithiasis secondary to TPM, the risk factors involved and the therapeutic and preventive options available in dealing with this side effect, which occurs in a low percentage of cases but which usually means stopping administration of this therapy. We therefore believe it necessary to analyse the risk factors for nephrolithiasis before prescribing the drug and we suggest that generalised preventive measures should be implemented, especially in children who are carriers of encephalopathies or conditions that reduce mobility.

Urolithiasis in rats consuming a dl bitartrate form of choline in a purified diet

Urolithiasis appeared in rats maintained to study the effects of nutrients and methylmercury on development and aging. After a year, the mortality rate was approximately 10%, and by 2 years, it had increased to nearly 30%. Clinical signs and urinary tract pathology were examined as a function of diet, duration on diet, gender, methylmercury exposure, genetics, and other potential risk factors by using survival analyses and qualitative comparisons. Urolithiasis in female rats appeared 15 weeks after beginning a purified diet and after 5 weeks for male rats. After 97 weeks, the mortality rate of female rats was 22% and for male rats was 64%. Lifetime urolithiasis-associated mortality was about 2% in a group of rats that consumed the contaminated diet for < 30 weeks. No urolithiasis occurred in siblings or cohorts of the rats described here that were maintained on a standard rodent chow containing choline chloride. Urolithiasis was traced to racemic, rather than levo-, bitartaric acid in some purified diets shipped in 2001 and 2002. It is unknown when the impurity first appeared in the diet, so estimates of exposure duration are upper limits. Chronic methylmercury exposure increased vulnerability. Some families (dam + offspring) had multiple cases of urolithiasis, but probability models constructed to evaluate familial clustering revealed no evidence for a genetic predisposition to urolithiasis apart from gender. Removing racemic tartaric acid did not decrease mortality once rats had been on the diet for 20 to 30 weeks, but it helped when exposure duration was shorter.

Spontaneous dissolution of a guaifenesin stone

Guaifenesin is a commonly used expectorant whose use may lead to the occasional formation of guaifenesin urinary stones. We herein describe a patient who was taking 2400 mg Guaifenesin per day as part of his treatment for asthma. He had a past history of a guaifenesin stone removed ureteroscopically. His current presentation was with a 9 mm by 6 mm stone in the upper left ureter, seen on CT scan, and treated initially with a ureteral stent and hydration. After 3 weeks, the stone had disappeared, as confirmed by repeat CT scan. The genesis and treatment of guaifenesin stones is discussed.

Sulfadiazine-related obstructive urinary tract lithiasis: an unusual cause of acute renal failure after kidney transplantation

We report on the first case of acute renal failure related to obstructive urinary tract lithiasis involving sulfadiazine crystals in a kidney transplant recipient. This patient had disseminated toxoplasmosis which was treated by sulfadiazine (4 g/day) and pyrimethamine (50 mg/day). In the fourth week of anti-toxoplasmosis therapy, he presented with obstructive acute renal failure: the plasma creatinine level increased from 220 micromol/l to 547 micromol/l. Apercutaneous pyelography was conducted showing the presence of a lithiasis located at the junction between the graft ureter and the bladder. Six days later, he underwent surgery to retrieve an orange-colored, friable stone. Its spectrophotometric analysis confirmed that the stone consisted of N-acetyl sulfadiazine crystals.

Counteraction of oxalate induced nitrosative stress by supplementation of l-arginine, a potent antilithic agent

BACKGROUND

Our understanding of nitrosative stress in the process of urolithiasis is far from complete. Earlier studies carried out in our laboratory demonstrate the presence of nitrated THP in stone formers, l-arginine (l-arg) a precursor of nitric oxide (NO), attenuates the endothelial dysfunction caused by reactive nitrogen species. We investigated the role of l-arg in ethylene glycol (EG)-induced urolithic rat model and observed its antilithic and antioxidative properties.

METHODS

Hyperoxaluria was induced using 0.75% EG in drinking water. l-arg [1.25 g/kg body weight] was given orally for a period of 28 days.

RESULTS

EG-treated rats showed significant loss in body weight and increase in the activities of oxalate synthesizing enzymes such as glycollic acid oxidase in liver. Lactate dehydrogenase activity in liver and kidney was increased. The activity of the free radical producing enzyme xanthine oxidase, tissue oxalate and calcium levels were significantly increased in EG-treated rats. Depletion in the antioxidant enzymes, membrane bound ATPases and thiol status was observed in these rats. l-arg co-supplementation to EG-treated rats maintained the activities of the oxalate synthesizing enzymes and free radical producing enzymes with in the normal range. Tissue oxalate and calcium levels were also maintained near normal in l-arg treated hyperoxaluric rats. l-arg, by its cytoprotective effect, maintained the thiol status, thereby preserving the activities of the membrane bound ATPases and preventing proteinuria and subsequent weight loss in EG-treated rats.

CONCLUSION

l-arg feeding prevents the retention of calcium oxalate crystals in hyperoxaluric rats by way of protecting the renal cells from oxidative injury and also by providing a second line of defense through the normalization of the oxalate metabolism. It reduces the risk of stone formation, by curtailing free radicals and hyperoxaluria as both of them have to work in close association to form stones.

Pseudoephedrine and guaifenesin urolithiasis: widening the differential diagnosis of radiolucent calculi on abdominal radiograph

Unenhanced helical computed tomography has played an increasingly important role in the management of urinary tract stones, guiding diagnosis and control of calculus disease. We report computed tomographic and radiographic appearances of a renal calculus composed of pseudoephedrine and guaifenesin in a patient who abused over-the-counter allergy medication.

Effect of antiepileptic drug polytherapy on crystalluria

Urolithiasis is a rare side effect of antiepileptic drugs. To clarify the risk factors for urolithiasis induced by antiepileptic drugs, the effect of antiepileptic drug monotherapy on crystalluria was studied, and zonisamide or sulthiame therapy and alkaline urine were demonstrated to be risk factors. In the next investigation, the effect of antiepileptic drug polytherapy on crystalluria was retrospectively studied in epilepsy patients treated for more than 1 month during the last 7 years. A total of 278 urine specimens from epilepsy patients aged between 7 months and 36 years were enrolled in this study. The mean age was 12.3 years. There were 109 samples from females and 169 from males. Antiepileptic drugs administered in this study were valproate (174 urinary samples), zonisamide (139), carbamazepine (138), phenobarbital (65), phenytoin (52), acetazolamide (17), clonazepam (15), sulthiame (6), ethosuximide (6), nitrazepam (4), and clobazam (4). Epilepsy patients treated with antiepileptic drug polytherapy were frequently found to have crystalluria in patients demonstrating alkaline urine and taking acetazolamide, zonisamide (particularly with high serum levels), or many antiepileptic drugs in combination. Regular urinalysis seems to be necessary in these patients, and the evaluation for urolithiasis should be performed if persistent crystalluria is demonstrated.

[Indinavir and renal lithiasis]

Indinavir is a new specific and potent drug that inhibits, like other antiretroviral agents, the protease of immune deficiency virus (HIV) or acquired immune deficiency syndrome (AIDS), an enzyme necessary to maduration and replication of the virus. Indinavir has the capacity to bind the active site causing a decrease in plasma of HIV1-RNA and an increase of T-CD4 helper lymphocytes. The aim of this work is to study in HIV and/or AIDS patients treated with indinavir the crystalluria and the formation of renal calculi due to the clearance of this drug. Two out of nine patients studied in this work presented abundant crystalluria and one of them presented spontaneously passed renal stone. Urinary crystals were studied under polarized-light microscopy and renal stone was analyzed by infrared spectroscopy.

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.

Bilateral urinary calculi after treatment with a silicate-containing milk thickener

Nephrocalcinosis and/or urinary calculi are rare in infants. Furosemide treatment during the neonatal period, vitamin D intoxication, hereditary diseases such as hyperoxaluria or distal tubular acidosis are among the most common aetiologies. We report the case of a 6-month-old boy with an extra-hepatic biliary duct atresia treated by the Kasai procedure and a gastro-oesophageal reflux treated with a silicate containing milk thickener (Gelopectose, 5.5% colloidal silicate) since the neonatal period. He did not present any other endogenous risk factor for urinary stone formation (normal urinary calcium/creatinine ratio; normal urinary magnesium excretion). The nephrolithiasis was discovered as the boy presented painful episodes of macroscopic haematuria. Ultrasound examination revealed bilateral nephrocalcinosis and multiple bilateral calculi without infection or urinary obstruction. Infrared spectroscopy revealed silicate as the major component suggesting silicate absorption to be responsible for the described symptoms. After replacement of the silicate-containing agent by a silicate-free milk thickener, the lesions were completely reversible as confirmed by repeated renal ultrasound examinations over a 2-month period.

CONCLUSION

Silicate-containing milk thickeners can be responsible for urinary calculi and/or nephrocalcinosis.

Urolithiasis associated with topiramate

OBJECTIVE

Topiramate is a sulfamate-substituted monosaccharide anticonvulsant used as adjunctive therapy for intractable refractory seizures. It is report a case of topiramate-induced urolithiasis.

CASE REPORT

A 35-year-old man presented with acute, right-sided, colicky flank pain. He denied hematuria or dysuria. He was in use of phenytoin, risperidone, phenobarbital, and topiramate. The total daily dose of topiramate was 375 mg. A CT scan showed a 7 x 1 mm curvilinear density at the right ureterovesical junction with proximal hydrouretronephrosis. He was managed with rigid ureteroscopic stone extraction and the calculus metabolic analysis revealed the stone was composed of carbonate apatite (70%), calcium oxalate dihydrate (20%), and calcium oxalate monohydrate (10%).

COMMENTS

The present case typifies many features of topiramate-induced urolithiasis. Those who care for patients with urinary stone disease should be aware of this association.

Treatment of indinavir sulfate induced urolithiasis in HIV-positive patients

Indinavir sulfate is a protease inhibitor used of the treatment of primary HIV infection either as monotherapy or as part of antiretroviral treatment schemes. Approximately 10% of all patients develop urolithiasis with radiolucent stones consisting of indinavir. We present our results of the treatment in 11 HIV positive patients (9 men, 2 women), who developed Indinavir lithiasis after 5-8 months of antiretroviral therapy. Following the initial procedures (spasmoanalgetic drugs, ureteroscopy, double J-stent or nephrostomy), the patients were further treated by increasing diuresis and urinary acidification. All the patients responded well to the treatment, the obstruction was releieved and their renal function was restored to normal.

Cardiovascular Drugs and Serum Uric Acid

Uric acid (UA) is the final product of purine catabolism in man, and it is excreted mainly by the kidneys when renal function is not impaired. Consequently, serum (S) UA increases as a function of purine intake, and it varies inversely to uricosuria. The latter variable diminishes in response to low-sodium intakes and vice versa. Insofar as the diet is not usually controlled in studies in which the response of SUA to drugs is evaluated, most reports are to be considered cautiously. Common diuretics elevate SUA in healthy subjects, hypertensives and patients with heart failure, apparently by elevating net UA reabsorption in the nephronal proximal tubule. This drug action, which becomes noticeable shortly after the institution of treatment and remains throughout it, starts at low doses (e.g., 12.5 mg hydrochlorothiazide or 1.25 mg bendrofluazide once daily in subjects with uncomplicated hypertension) and increases in dose-dependent fashion. Beta-blockers tend to elevate SUA. The angiotensin-converting enzyme (ACE) inhibitors captopril, enalapril and ramipril have been found to increase uricosuria mildly, likely by lowering the net reabsorption of UA in the proximal tubule. These three drugs and lisinopril can blunt the rise in SUA provoked by diuretics in hypertensives if used at sufficiently high doses relative to the dose of the diuretic. The angiotensin II antagonist losartan augments uricosuria mildly and thereby decreases SUA. The cardiovascular implications of the response of SUA to drugs remain speculative. Uric acid can scavenge various reactive oxygen species and thus reduce oxidative stress, which seems to contribute to the development and/or progress of various cardiovascular conditions, including hypertension, atherosclerosis and heart failure. Consequently, it may be theorised that the elevations in SUA induced by diuretics might contribute to the established favourable action of these agents on cardiovascular prognosis. Conversely, diuretic-induced increases in SUA are to be considered detrimental according to an old hypothesis that maintains that SUA is a cardiovascular risk factor; this construct is largely based upon the results of selected epidemiological undertakings. The cardiovascular implications of the effects of drugs on SUA, if any, should be elucidated through purposive research.

Effect of ascorbic acid consumption on urinary stone risk factors

PURPOSE

Ascorbic acid (AA) has been implicated as a risk factor for calcium oxalate stones due to its conversion to oxalate and potential acidifying properties. We evaluated the effect of AA consumption on urinary saturation of calcium oxalate (CaOx) and urinary pH.

MATERIALS AND METHODS

A total of 12 normal subjects (NS) and 12 CaOx stone formers (SF) underwent 2, 6-day phases of study while maintained on a controlled metabolic diet. In each phase subjects ingested 1 gm AA or an identical appearing placebo twice daily. On the last 2 days of each phase 2, 24-hour urine collections were analyzed for pH and stone risk factors, and blood specimens were submitted for serum chemistry studies.

RESULTS

No difference in urinary pH was found between placebo and AA phases in NS (6.02 versus 6.02) and SF (6.0 versus 6.0). However, urinary oxalate was statistically significantly higher in the AA versus placebo phase for NS (34.7 versus 28.5 mg, p = 0.008) and SF (41.0 versus 30.5 mg, p <0.001). Likewise, the CaOx relative saturation ratio was significantly higher in the AA versus placebo phase for both groups.

CONCLUSIONS

Ingestion of 2 gm AA daily results in no change in urinary pH but a moderate though statistically significant increase in urinary oxalate in NS (20%) and SF (33%). Stone formers respond no differently to AA than normal subjects. We recommend limiting AA use to less than 2 gm daily in CaOx stone formers.

Silica urolithiasis in the dromedary camel in a subtropical climate

In 1998, two cases of silica urolithiasis occurred in castrated male dromedaries on an intensive camel farm in the Canary Islands. The immediate attributable cause was the ingestion of large amounts of silica in the feed, estimated as 84.44 g/day. An associated cause was the low level of salt in the diet. Daily ingestion of salt from feed and water was estimated to be 21.8 g (8.6 g of sodium). Seventy-six castrated males from the same farm were divided into four groups: group A received 30 g of salt daily; group B received 40 g; group C received 60 g; and group D received no added salt in the diet (control). The animals were maintained on these dietary regimes for 2 years. No animals from groups A, B or C suffered overt urinary retention. One animal from group D had an obstructive urinary retention 10 months after the study commenced. Thus, 52 g of salt daily appears to be sufficient to prevent urinary retention in dromedaries raised in a subtropical climate.

Oral bisphosphonate therapy for vitamin D intoxication of the infant

Vitamin D intoxication in infancy has serious consequences attributable to acute hypercalcemia and subsequent hypercalcuria/nephrocalcinosis. Current treatments of patients with vitamin D intoxication are unsatisfactory and associated with prolonged hypercalcemia. We now report the use of oral alendronate sodium in a 3-month-old infant with vitamin D intoxication. Short-term oral alendronate sodium treatment effectively corrected hypercalcemia/hypercalciuria, decreased the duration of hospitalization, and appears safe in 15 months of observation.

Urolithiasis in pediatric patients with acute lymphoblastic leukemia

We evaluated the incidence, timing, and consequences of urolithiasis in children with acute lymphoblastic leukemia (ALL). A total of 20 patients with urolithiasis were identified from 2095 patients with ALL treated at St Jude Children's Research Hospital on consecutive protocols between 1968 and 1998. For remission induction therapy, all patients received daily prednisone; continuation chemotherapy regimens differed by protocol with some including pulses of prednisone or dexamethasone and others no glucocorticoid. Patients with urolithiasis were older at diagnosis of ALL than those without urolithiasis (median age, 7.5 vs 5.0 years; P=0.03) and less likely to be black (P=0.03) than white or Hispanic, but sex and treatment era did not differ. Presenting symptoms included abdominal or flank pain, hematuria, and dysuria. All stones analyzed biochemically were calcium stones. The incidence of urolithiasis after completion of therapy was 1.8 per 10 000 person-years. Compared to this baseline rate, the relative risk of urolithiasis was 45 (P<0.01) during induction therapy, 22 (P<0.01) during continuation therapy with glucocorticoids, and 5.1 (P>0.05) during continuation therapy without glucocorticoids. Urolithiasis occurred 4.5 times more often during continuation treatment with glucocorticoids than without (P<0.05). Seven patients (35%) had recurrent urolithiasis. Patients with ALL are at risk of developing calcium renal stones during chemotherapy, especially when a glucocorticoid is included.

Urologic complications of nonurologic medications

A physician must be aware of common drug side effects and interactions before prescribing a certain agent. In addition to the drugs that we, as urologists, prescribe, we must also be aware of the urologic side effects of drugs that are commonly prescribed by nonurologists. The mechanisms of the pharmacologic causes for voiding dysfunction, erectile and sexual dysfunction, infertility, and urolithiasis are often mutifactorial and incompletely understood. The recognition and association of a particular drug's potential side effects may save valuable time and money involved in the workup of a patient with a new urologic complaint. It is incumbent on the practicing urologist to be able to recognize the common, and sometimes subtle, urologic complications of medications that are used for nonurologic conditions.

[A case of urolithiasis due to vitamin D intoxication in a patient with idiopathic hypoparathyroidism]

We report a case of urolithiasis in a patient with idiopathic hypoparathyroidism treated with vitamin D therapy. A 30-year-old woman with idiopathic hypoparathyroidism, who had been treated with vitamin D therapy with 2-4 micrograms/day of alpha-calcidol for 9 years, was admitted for recurrence of bilateral renal stones and progressing left hydronephrosis. Laboratory data revealed normal serum calcium level and remarkable hypercalciuria. The dose of oral administration of alpha-calcidol was reduced to 1 microgram/day and 2 mg/day of trichlormethiazide was started. Now her serum calcium concentration and the total amount of urine calcium was completely under control. Bilateral renal stones are no longer progressive and tetany has not been recognized. We considered it essential to monitor closely not only the serum but also the urine calcium level in the vitamin D therapy for idiopathic hypoparathyroidism.

[Analysis on the components of rat urinary stone induced by terephthalic acid]

In order to analyze the components of rat urinary stone and to explore the possible mechanism of chemically induced bladder cancer, terephthalic acid (TPA) is orally administrated to rats at the doses of 5000 and 500 mg/kg/BW/everyday for consecutive 90 days and stones in bladder and kidney are collected. Inductive Coupled Plasma Quantomer (ICP), Element Analyzer (EA) and Fourier Transform Infared Spectrometer (FT-IR) are applied for the analysis on the components of stone in bladder and kidney. The results showed that the main components of the stone are calcium, carbon, nitrogen, hydrogen and phosphorus. The FT-IR showed that the stones both in bladder and kidney might contain nitrous, carbonate, ammonium salt, and para-position replaced benzene-ring compounds, but no original TPA is detected. The findings indicate that TPA might have a metabolic turnover inside the rat body, and, at least, might not be completely excreted in its original form.