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PubMed2005

Artificial neural networks in urolithiasis.

PURPOSE OF REVIEW: The management of urolithiasis is a clinical challenge worldwide which may result in difficulty in diagnosis, treatment and prevention of recurrence. Artificial neural networks (ANNs) are well described adjuncts to many aspects of clinical urological practice. We review literature published in on-line Medline-citable English language journals to assess whether ANNs are useful in clinician-led decision-making processes in urolithiasis. RECENT FINDINGS: Studies have examined the role of ANNs in prediction of stone presence and composition, spontaneous passage, clearance and regrowth after treatment. These reports suggest that ANNs can identify important predictive variables and accurately predict treatment outcome. SUMMARY: Although well described in general urological practice, there is comparatively little research into the role of ANNs in urolithiasis. Initial results appear promising; however, further prospective studies are necessary to determine if this mode of analysis is superior to standard statistical predictive methods.

Diagnosis, Differential↗
PubMed2005

Analysis of bone mineral density in urolithiasis patients.

BACKGROUND: The association between hypercalciuria and bone mineral density (BMD) has been already recognized. The aim of the present study is to relate BMD to age and sex and to evaluate the calcium metabolism and hypercalciuria-defined dietary or non-dietary category in patients with urolithiasis. METHODS: The BMI of the L2-L4 lumbar vertebrae was measured in 310 renal stone patients (191 men and 119 women). Percent age matched score (%AMS), which is the percent ratio of measured BMD to the mean BMD of age-matched control subjects, was utilized for the appraisal of BMD. Low BMD groups were defined by lower than 90% of %AMS. RESULTS: Low BMD was observed in 27.7% of urinary stone patients, which was not a significant difference to that of control subjects (23.5%) who were measured in the health examination. In male patients with urolithiasis, the frequency of patients in whom BMD had been apt to decrease since youth was high, but there was not a proven significant difference among the three age groups (20-39 years old, 40-59 years old and 60 years old or older). In contrast, for female stone patients, the frequency of low BMD markedly increased in patients aged 40 years or older, when menopause occurs. Furthermore, in female stone patients with hypercalciuria, the frequency of reduced BMD reached more than 40%. When the cause was non-dietary hypercalciuria (classified mainly on the daily amount of urinary calcium excretion after ingestion of calculus test diet), the frequency of reduced BMD reached 65% (P < 0.01). CONCLUSIONS: In case female stone patients with non-dietary hypercalciuria become menopausal, not only the risk of recurrent lithiasis increases, but the possibility of developing osteopenia in the future also increases. Appropriate treatments for prophylactic effects on urolithiasis or osteopenia should be considered, as judged from BMD, diet, sex, urinary calcium excretion and other factors synthetically.

Absorptiometry, Photon↗
PubMed1999

Urinary glycosaminoglycan excretion in urolithiasis.

Urinary glycosaminoglycan (GAG) excretion was measured in children with idiopathic urolithiasis (15 girls and 10 boys; mean (SD) age 6.2 (2.4) years) and in healthy controls (10 girls and 14 boys; mean (SD) age 6.8 (3.8) years). GAG excretion was expressed as a GAG/creatinine (mg/g) ratio and was evaluated using dimethylmethylene blue. In healthy control children, the mean (SD) GAG/creatinine ratio was 31.67 (12.76) and it was similar in girls and boys. The children with idiopathic urolithiasis had significantly lower mean (SD) GAG/creatinine ratios than controls (22.59 (7.35)). Therefore, urinary GAG excretion may be important in the disease process in children with urolithiasis, as it is in adults.

Biomarkers↗
PubMed1987

Role of magnesium in the aetiology of ovine urolithiasis in fattening store lambs and intensively fattened lambs.

High dietary levels of magnesium (greater than 2 g/kg drymatter [DM]) have been implicated as the main causal factor of urinary calculi in concentrate-fed lambs. Experiments were performed to try to reproduce this effect of high magnesium (from added calcined magnesite) on the incidence of urolithiasis in lambs. In the first, store lambs were given diets containing magnesium in the following concentrations: A,2.9; B,8.6 g/km DM. Twenty-four blackface lambs were each allocated to A and B and the control group of 160 lambs was fed a combined dried grass/sugar beet pulp pellet and hay ad libitum (diet C). The animals were housed and fed ad libitum until they were killed at an average liveweight of 35 kg. No animals showed clinical signs of urolithiasis and post mortem only a trace of calculous material was recovered from one lamb fed diet A. In the second experiment housed Suffolk and Suffolk cross lambs were fed a starter beginning at three to four weeks old and changed to a finisher at a liveweight of 23 kg. The feeds were either high magnesium starter (5.7) and finisher (6.0) or low magnesium starter (2.3) and finisher (2.8 g/kg DM). Twenty-two single lambs and 32 twins were assigned to both high and low magnesium diets. Lambs fed additional magnesium drank more water/kg DM intake and one of the single lambs showed clinical signs of urolithiasis and was killed. No others showed clinical signs and from the 62 killed there was no post mortem recovery of calculous material.

Animals↗
PubMed1979

Epidemiological and clinical significances of urolithiasis in childhood.

An epidemiological and clinical study of a sample of 105 children with urolithiasis treated in the period 1965-1974 in a defined population of children revealed a decrease in the rate of incidence of this disease in a municipal infant population with high-ranking care for their health. Serious forms of urolithiasis are on the decrease. There is a higher rate of incidence in schoolboys and schoolgirls, the latter being more often involved than boys. Despite the general lower rate of occurrence, urolithiasis still has such forms as will endanger the life of the organ and the life of the patient. Injury to health of the child by this disease consists mainly in loss of one kidney, ambilateral staghorn stones that proved irremovable in their entirety and pyelonephritis.

Calcium Oxalate↗
PubMed1982

Urolithiasis in childhood. A study of 181 cases.

181 of 2,606 patients hospitalized for urolithiasis in 12 years were younger than 15 years (6.9%). In accordance with the data given by other authors, we found the incidence of urolithiasis in children to be 1-5%, which, at least in Central Europe, corresponds approximately with that in adults. The causative factors or cofactors we established were malformation of the kidneys and urinary tract in 35.9%, and infections of the urinary tract in 80.7%. Defined metabolic disorders were found in only 5.5% of patients. Stone analysis showed a predominance of phosphate-containing calculi. Control examinations were done in 154 children over periods of 6 months to 11 years. "Recurrent lithiasis' was seen in 32 patients, however, the exact comparison of pre- and postoperative X-ray films showed that in 17 cases the calculi had not been completely removed during surgery (11%). Consequently, a real recurrent lithiasis was present in 15 children only (9.9%). Since the West Berlin population includes a high percentage of Turkish people, we can conclude from our case material that even those Turkish children who were born in West Berlin suffer from urolithiasis 2-2.5 times as often as German children of the same age-groups.

Adolescent↗
PubMed1990

Epidemiology of urolithiasis in Japan: a chronological and geographical study.

A nationwide survey on urolithiasis in Japan between 1965 through 1987 was carried out, succeeding the previous 1955 and 1966 studies, in an effort to evaluate chronological and geographical changes in urolithiasis among the Japanese people who are relatively racially homogenous and living with similar customs and habits, which have changed dramatically from the old Japanese to westernized modes in a very short period after the Second World War. Incidence of calcium-containing urinary stones in the upper urinary tract has been increasing in Japan since the Second World War with increasing westernization of life-style and industrialization, with the annual incidence of urolithiasis steadily increasing from 53.8/100,000 general population in 1965 to 92.5 in 1985. According to the data, 5.4% of the population may be expected to develop a urinary calculus at least once in their life time. Analysis of 69,949 stones obtained during the years from 1978 to 1987 with infrared analysis showed that 79.4% were calcium oxalate and/or calcium phosphate stones, 7.4% were struvite with or without carbonate apatite, 5.2% were uric acid or urate, and 1.0% were cystine. In the era of new treatment modalities such as the endourological surgery and the extracorporeal shock wave lithotripsy, open surgical treatments were replaced with new types of treatment in about 75% of the cases in 1985.

Calcium↗
PubMed1992

Inhibitors of calcium oxalate crystallization and urolithiasis.

In urolithogenic processes both, promoters and deficit of inhibitors, play an important role. The inhibitory action of added inhibitors (magnesium, citrate, pyrophosphate and chondroitin sulphate) was investigated using the urine of 72 patients with calcium urolithiasis. It was concluded that the deficit of inhibitors seems to be an important cause of stone formation in idiopathic oxalocalcic urolithiasis. Nevertheless, when that specific heterogeneous nucleation takes place it becomes an important factor and the inhibitor plays a complementary role in calcium oxalate urolithiasis.

Calcium Oxalate↗
PubMed1978

A biochemical basis for grouping of patients with urolithiasis.

The urinary excretion of calcium, magnesium, oxalate, creatinine, phosphate and urate was investigated in patients with urolithiasis and in normal subjects. The excretion of oxalate and urate per mole creatinine and the quotients calcium/magnesium, calcium X oxalate/magnesium and calcium X oxalate/(magnesium X creatinine) were significantly higher in stone formers than in normal subjects. The mean creatinine-correlated urinary excretion of calcium was higher and of magnesium lower in patients with urolithiasis, but the differences were statistically not significant. The urine investigation was supplemented with analysis of calcium, magnesium, creatinine, urate, bicarbonate and chloride in serum and a qualitative analysis of stone composition. A simple schedule for a biochemical grouping of patients with urolithiasis is presented and on the basis of the analytical findings it was possible to classify 67% of patients with so-called 'idiopathic stone disease' according to these principles.

Adult↗
PubMed1997

Etiological and clinical patterns of urolithiasis in Turkish children.

OBJECTIVE: To evaluate the clinical and etiological characteristics of childhood urolithiasis in Turkey. METHODS: Ninety-two children with urolithiasis were studied retrospectively according to clinical patterns and etiological factors between January 1990 and January 1995. RESULTS: The age range of the patients was from 2 months to 14 years (mean age 6.9 years), and there was a male/female ratio of 1.6. The onset of the disease was earlier in boys than in girls. The most striking features were the initial admission of 14 (15.2%) children after the development of chronic renal failure and that most of them (64.3%) had infection stones. The stones were localized in the upper urinary system in 68.5% of the patients; bladder stones were rare (10.9%). The recurrence rate at presentation was 15.2% in all patients. As etiological factors, an anatomical defect was found in 30.4% of the patients, infections in 31.5%, and metabolic disorders in 26.1%; 11 (12.0%) of them were classified as idiopathic. The earliest presentation was seen with metabolic and infection stones and the highest recurrence rate (37.5%) in patients with metabolic stones. CONCLUSION: Childhood urolithiasis is a serious problem in Turkey. In order to prevent the development of end-stage renal failure and to improve the patients' quality of life, more efforts should be made with respect to early diagnosis and management of renal stones and urinary tract infections.

Adolescent↗
PubMed1996

Suspected urolithiasis in pregnant women: imaging algorithm and literature review.

Urolithiasis during pregnancy is a difficult clinical problem in which carefully selected radiologic studies play an essential role. For years excretory urography has been the standard of care in the radiologic evaluation of urolithiasis in pregnancy. Recently, sonography, particularly Doppler sonography, has evolved as an invaluable tool in the armamentarium of radiologists facing this challenging problem. In experienced hands, the diagnosis of urolithiasis in pregnancy can be made confidently using Doppler sonography and, when necessary, excretory urography.

Algorithms↗
PubMed2003

Medical management of urolithiasis, what opportunity for phytotherapy?

Urolithiasis is the formation of stones in the urinary tract, causing pain and bleeding, and may lead to secondary infection. It is the third most common affliction of the urinary tract. Of many types of stones that are formed, the most common are calcium oxalate. The formation of such concretion encompasses several physico-chemical events beginning with crystal nucleation, growth, aggregation, and ending by retention within urinary tract. The mechanisms governing the induction of all these processes remain speculative. One of the important phenomena that characterizes urolithiasis is its high recurrence. Thus, a protective system is required including extracorporeal shock wave lithotripsy and medicament treatment. Unfortunately, these means remain costly and in most cases are invasive and with side effects. Therefore, it is worthwhile to look for an alternative to these conventional methods by using medicinal plants or phytotherapy. In fact, many developing countries including China use herbal medicines which have gained popularity in Europe and are becoming increasingly in the United States as well. As far as urolithiasis is concerned, several herbal treatments seem to cure lithiasis patients. Nevertheless, the effectiveness and the mechanism by which these plants work has not been fully undertaken by using scientific and objective methods. Therefore, it is highly recommended to explore new drugs coming from medicinal plants to treat and prevent the formation of kidney stones. Ideally, conventional and phytotherapy should supplement one another and have all the need available for lithiasis patients.

Animals↗
PubMed2005

Risk factors determining active urinary stone formation in patients with urolithiasis.

AIMS: The goal of clinical and metabolic evaluation of patients with urinary stones is to identify patients at high risk for recurrent stone formation and as such, to allow the practitioner to suggest preventive therapies. However, knowledge about risk factors for active stone formation in patients with urolithiasis is limited. This study was initiated to assess the significance of several metabolic and clinical parameters for the determination of the risk of active stone formation. METHODS: Study in 320 consecutive outpatients referred to our clinic for metabolic analysis. Clinical and metabolic parameters were determined by standardized procedures of questionnaires, serum biochemical profiles and urinalysis. RESULTS: In 21.5% of 284 patients with complete data stone formation was active. Hypercalciuria, hypocitraturia and urinary tract infections had odds ratios for active stone formation above 2.5, whereas the odds ratio of a positive family history was 0.38. Hyperuricosuria, hyperoxaluria and a low urinary volume did not influence the risk for active stone formation. CONCLUSION: The risk profile for active stone formation differs from the risk profile for urolithiasis in general. Metabolic evaluation and determination of those risk factors in patients with urolithiasis might improve the estimation of the risk of future stone formation.

Adult↗
PubMed1991

[Studies on calcium oxalate crystal formation in urolithiasis. Multi-regressive analysis of urinary CaOx crystalline volumes and the effects of urinary various substances on CaOx crystal formation].

Because human urine contains various substances which can affect each other, it is quite difficult to clarify the mechanism of formation of calcium oxalate (CaOx) crystal in urine. The authors recently determined CaOx crystalline content and the concentrations of other substances in urine specimens from patients with urolithiasis and healthy volunteers, and subjected the data to multi-regressive analysis for the purpose of assessing the effect of these urinary substances on CaOx crystal formation. 1. In analysis of urine from patients with urolithiasis, the partial correlation coefficients of CaOx crystal formation with oxalic acid, sodium, calcium, uric acid magnesium were 0.67, 0.28, 0.18, and -0.10, respectively. The formula of regression was as follows: Amount of CaOx crystal (X 10(6) microns3/ml) = 3.59 X 10(-2) Ox (mM/L) + 4.72 X 10(-3) Ca (mM/L) + 4.52 X 10(-3) Na (mM/L) + 2.51 X 10(-4) UA (mM/L) -2.39 X 10(-2) Mg (mM/L) -1.65. The multiple correlation coefficient was 0.759. Thus, in patients with urolithiasis, urinary crystal formation was most dependent on the oxalic acid level, sodium, calcium, and uric acid were found to promote crystal formation, while magnesium to suppress it. 2. In analysis of urine from healthy volunteers, the partial correlation coefficients of CaOx crystal formation with oxalic acid and inorganic phosphorus were 0.51 and -0.24, respectively. The formula of regression was as follows: Amount of CaOx crystal (X 10(6) microns3/ml) = 1.91 X 10(-2) Ox (mM/L) -3.43 X 10(-4) P (mM/L) +0.29 The multiple correlation coefficient was 0.525.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗
PubMed1998

[A study of the differences between the sexes in epidemiology of urolithiasis].

PURPOSE: Uroithiasis seems to be the dominant disease for male. In the recent Japanese epidemiological report, the sexual ratio was reported 2.3:1. This sexual ratio is almost stable from 1960. We studied epidemiologically based on age and stone components the differences between the sexes. PATIENTS AND METHOD: From 1977 to 1996 the upper urinary tract stones which spontaneous excretion or surgical removal in our hospital were the subjects of study, Stone analysis was carried out infrared spectrometer. The statistical analyses were performed by the chi-square test and Mann-Whitney's U test. Significance was declared for a probability value of less than 0.05. RESULTS: In the epidemiology of our treated patients sexual ratio was 1.83:1. We studied sexual ration in age and stone components. The sexual ratio of the patients, 60 years and over was decreased compared with that of the patients under 60 years of age. We found the tendency that the sexual ratio was decreased at 60 years old and over. In the female urolithiasis patients less than 60 years old the frequency of calcium oxalate contained stone patients was predominantly smaller than male. In the female urolithiasis patients of 60 years and over the stone component ratio was similar to male urolithiasis patients. CONCLUSION: In point of frequency sexual ratio was decreased at 60 years old and over. In the female patients less than 60 years old the frequency of calcium oxalate contained stone was predominantly small. This low frequency of calcium oxalate contained stone in the female less than 60 years old seemed to be a factor of the sex differences of frequency.

Adolescent↗
PubMed2003

[A case of urolithiasis associated with short bowel syndrome].

We report a case of urolithiasis associated with short bowel syndrome. A 56-year-old woman was admitted to our hospital for asymptomatic bilateral renal stones. She had received extensive resection of small intestine due to strangulating obstructive ileus 7 years ago (residual intestine, only 20 cm). Subsequently, she was in a state of short bowel syndrome. Plain film of kidney, uteter, bladder and computed tomography revealed bilateral renal stones (right 4 mm, left 10 mm). The left renal stone was successfully treated by extracorporeal shock wave lithotripsy. Since the right renal stone was small, no treatment was performed. The stone fragments were composed of calcium oxalate and calcium phosphate, and excessive urinary excretion of oxalate (103.8 mg/day) was observed. In this patient, urolithiasis was diagnosed to be due to enteric hyperoxaluria caused by short bowel syndrome. To prevent the recurrence of stone formation, she was treated with oral administration of calcium lactate, sodium/potassium citrate and magnesium oxide. We review the Japanese literatures on urolithiasis with short bowel syndrome.

Calcium Compounds↗
PubMedDate not supplied

[Urolithiasis: current views on pathogenesis, course and treatment].

Urolithiasis was suspected in 14,000 patients. Results of relevant examinations are presented. Urolithiasis is encountered in 7.1% of the population. The disease onset seems to result from systemic and renal hormonal dysfunctions. Marriage of two close relatives, unbalanced diet can also contribute to development of urolithiasis. Conservative, surgical and shock-wave treatments are discussed in pathogenetic aspect.

Azerbaijan↗
PubMed1975

Control of oxalate urolithiasis by DL-alanine.

Oxalate urolithiasis in male rats was experimentally induced by feeding a basal diet composed of Purina laboratory chow and 3 per cent glycolic acid. When this basal oxalate calculus-producing diet containing 10 per cent alanine was fed to rats, the incidence of oxalate urolithiasis was markedly reduced. Moreover, when Purina laboratory chow containing 10 per cent alanine was fed to rats which had been on the calculi-producing basal diet for 4 weeks, it appeared that most uroliths were dissolved. Excess intake of alanine increased the concentration of alanine in urine and this apparently aided in the prevention and treatment of urolithiasis.

Administration, Oral↗