[Impact of mydriatic eyedrops on distance visual acuity in patients with exudative age-related macular degeneration]. / Impact de l'instillation de collyres mydriatiques sur la mesure d'acuité visuelle de loin chez des patients présentant une DMLA exsudative.

PURPOSE: To demonstrate a decrease in distance visual acuity (VA) following instillation of mydriatic eyedrops in eyes with exudative age-related macular degeneration (AMD). MATERIALS AND METHODS: A prospective assessment in clinical practice was conducted in our ophthalmology department at the University Hospital of Tours from 7/19/2018 to 8/29/2018. Distance (ETDRS) and near (Parinaud) VA were assessed before and after instilling one drop each of tropicamide 0.5% and phenylephrine 10% in the 40 included eyes with exudative AMD. RESULTS: The mean difference in distance VA before and after pupillary dilation (PD) was 0.06 LogMAR (SD=0.14) (P<0.01), i.e. -3.05 letters read (SD=7.52) on the ETDRS chart (P=0.01). For near VA, the mean difference was 0.16 LogMAR (SD=0.16) (P<0.001), i.e. -1.58 paragraphs read (SD=1.63) on the Parinaud chart (P<0.001). DISCUSSION: The absence of a clinically significant loss in post-dilation distance VA for exudative AMD could be explained by negligible glare coming from the ETDRS chart, milder photophobia, low pre-dilation VA's and a balance between higher order optical aberrations and diffraction. The opposite result for near VA could essentially be explained by greater glare induced by the light illuminating the Parinaud chart. CONCLUSION: Our primary goal was not achieved. A study presuming the absence of a clinically significant decrease in post-dilation distance VA would be necessary to consider directly measuring post-dilation VA in eyes with exudative AMD in our daily practice.

[Individualized patient care with urological implants using biofilm-resistant surface concepts]. / Individualisierte Patientenversorgung mit urologischen Implantaten durch biofilmabweisende Oberflächenkonzepte.

Urological implants in the urinary tract are routinely used to ensure urine flow. However, the morbidities are numerous concerning long-term derivations. Especially with the ureteral stents, failure can have considerable consequences. Since the surfaces of all urological implants are more or less ideal substrates for microorganisms, the formation of bacterial biofilms is a regularly observed and often serious complication, which in many cases forces early implant replacement. The burden on the patient and the health system are enormous. This article provides an overview of the numerous strategies developed or under development to protect against bacterial adhesion. Observations in use show "sometimes good, sometimes bad results" for all strategies, which may be due to the fact that the treated patients have different biological and clinical conditions. The implants are each equipped with defense mechanisms designed for certain "scenarios"; if they are used inadequately in this respect, they cannot optimally fulfill their task. Systematic observations of the "outcomes" and evaluation of the obtained data would be necessary in order to be able to assign an "optimal" effect spectrum to each defense strategy, thus, ultimately prospectively giving patients the most suitable product in advance. Systematic use of the existing implant concepts can avoid a large number of implant-related complications "ad hoc"; further development steps with regard to improved surface modifications can be made more specifically. However, the hope of a "super strategy" is likely to remain unfulfilled because bacteria as "opponents" have already proved billions of years of survival.

[Rare metabolic disorders and urolithiasis]. / Seltene Stoffwechselerkrankungen und Urolithiasis.

Numerous metabolic anomalies, which often have no direct pathological relevance when considered individually, are found in all people. In most patients with urinary tract stones, it can be assumed that a specific combination or interaction of these anomalies occurs, thus, resulting in stone formation, but only after individual exogenous risk factors are triggered. Lithogenesis is the result of a cascade of different "events" that are temporally close to one another, but sometimes these events interact strong enough that significant stone growth occurs. Chronic metabolic disorders usually lead to permanently altered urine compositions. The occurrence of physiological urine constituents in nonnormal concentration ratios and/or the nonphysiological excretion of metabolic products can significantly increase the lithogenicity of urine, so that urolithiasis can manifest itself as a clinical symptom. In cases of urolithiasis of unknown origin, a potentially hidden rare metabolic anomaly should always be considered. In addition, if a patient has a known metabolic disease, then this should always be taken into account as a risk factor for stone formation and attempts should be taken to clarify its influence on urine composition. This also applies to the efficacy of a therapy. A distinct link between a metabolic disease and stone formation is generally rare and will likely remain so despite significant advances regarding differential diagnosis and etiopathology. This article focuses on very rare metabolic causes and/or genetic syndromes which may be associated with urolithiasis. Patients receiving symptomatic stone treatment should receive life-long follow-up care from a urologist because reducing the recurrence rate helps to improve the quality of life of the patients.

[New diagnostic tool for individual monitoring of urolithiasis risk and other metabolic diseases]. / Neues Harn-Diagnostikverfahren zur individuellen Überwachung des Harnsteinrisikos und anderer Stoffwechselerkrankungen.

Urinary composition is the result of the interplay of all metabolic processes, including all metabolites and toxins produced. Any change in urine composition influences urinary supersaturation, the major thermodynamic driving force of crystal formation. Urolithiasis is a wide-spread disease with a prevalence rate of 4% to 10%. Formation risk of calcium-oxalate, by far the most common mineral in uroliths, is quantified by the Bonn-Risk-Index (BRI). The BRI measures induced crystal growth within native urine and shows superior diagnostic sensitivity and specificity compared to other urolithiasis risk indices. The concept of BRI quick test presented in this work allowes even untrained persons to easily determine the urolithiasis risk. Many diseases lack a simple, easily accessible and cost effective diagnostic approach to monitor their course and treatment success. Since BRI takes into account every constituent of native urine, it can be used to monitor a wide range of metabolic diseases.

[Carefully conducted preanalytic and postanalytic procedures for urine samples. Often neglected in urolithiasis treatment]. / Sorgsame Prä- und Postanalytik von Urinproben. Oftmals vernachlässigt in der Harnsteinnachsorge.

Particularly in the urological consultation sessions collection of 24 h urine samples is required to evaluate the metabolic risk factors for urolith formation. To ensure a yield from urinalysis of sufficiently high quality and to minimize the number of potential error sources, correctly performed preanalytical procedures are required. If certain basic quality criteria for the collection procedures are not being followed false data can be determined and the clinical interpretation based on that analysis will result in a wrong rating of the true metabolic status of patients. This article provides practical, feasible and proven solutions in an encouraging, motivating and clear way to ensure that at least the most important steps for a correct urine collection are being taken. The preanalytical requirements for the determination of other urinary parameters which are not in the direct focus of urolithiasis treatment will not be covered by this article.

[Nano-coatings: principle, range of applications, threats]. / Nano-Beschichtungen: Prinzip, Anwendungsbereiche, Gefahren.

Nano-technology, which already has entered many areas of our everyday life, represents one of the key technologies of the 21st century. Nano-coatings play an important role in many industrial processes (e. g. as wear-protective coatings). They are furthermore of increasing importance in medical technology (e. g. for biocompatible functionalization of medical implants). This article gives a short overview over principles, applications, production methods and risks of nano-coatings in medicine. Furthermore the consequences for clinicians and physicians will be discussed.

[Recurrence prevention of urolithiasis with respect to economic aspects]. / Rezidivprävention der Urolithiasis unter Berücksichtigung ökonomischer Aspekte.

Recurrence prevention in urinary stone disease not only makes good medical but also economic sense. Up to 40% of recurrences can be prevented by a rational urinary stone metaphylaxis whereby not only treatment costs but also the cost of lost productive work time can be saved. Detailed knowledge of stone composition and medical history of the patient is a prerequisite for a rational metaphylaxis which according to the S2 guidelines results in assignment to the high or low risk group. The required diagnostic and therapeutic measures are also decided by this classification. In addition to general metaphylaxis (reduction of overweight, physical activity, appropriate fluid intake, balanced diet) further specific measures may be necessary depending on the risk group and stone type.

[Stress-related alteration of urine compositions: idiopathic CaOx stone formers, patients with chronic inflammatory bowel disease (CIBD) and healthy controls]. / Stressbedingte Alteration der Harnzusammensetzungen : Untersuchung von idiopathischen CaOx-Steinbildnern, Patienten mit chronisch entzündlicher Darmerkrankung und gesunden Probanden.

BACKGROUND: Increased emotional stress in everyday life influences the way of living and metabolism of people living in developed countries. Contemporaneously, the incidence and prevalence of urolithiasis rises. Does a pathogenetically relevant relationship exist between chronic stress burden and permanently altered urinary composition? PATIENTS AND METHODS: The influence of chronic stress burden on urine composition and risk of urinary calcium oxalate (CaOx) stone formation was, for the first time, comprehensively investigated in 29 healthy controls (CG), 29 idiopathic CaOx stone formers (SF) and 28 patients suffering from chronic inflammatory bowel disease (CIBD). After 4 days with standardized nutrition, 24-h urine was collected. Extensive urinalysis was performed and APCaOx index calculated. Evaluation of subjective stress level was carried out by using the standardized and well-established questionnaire Trierer Inventar zur Beurteilung von chronischem Stress (TICS). The concentration values of the urinary parameters as well as the APCaOx values were linearly correlated with the stress scores obtained from the different items of the TICS. A significance level p≤0.05 was considered to indicate statistical significance. RESULTS: The mean APCaOx indices amounted to 0.8±0.3 in CG, 1.2±0.7 in SF and 1.9±1.2 in CIBD. The increased APCaOx in SF mainly results from relatively increased Ca and oxalate excretions, whereas in CIBD this also results from reduced urinary excretions of citrate and Mg as well as reduced 24-h urinary volumes. The calculation of linear correlation coefficients between a TICS stress dimension and a concentration value of a urinary parameter or APCaOx results in r values not exceeding 0.600. However, some of these correlations are statistically highly significant. In SF only one combination with Ca was observed, while in CIBD in contrast a number of combinations, in particular including Na, was obtained. In CG direct statistical relationships between stress burden and citrate as well as Mg exist. In this group, increased stress burden is associated with increased inhibitory potential to prevent CaOx stone formation. CONCLUSION: In the investigated study groups, differently complex relationships between amount of stress burden and risk of CaOx stone formation were observed, however, without obvious physicochemical principle(s). In some individuals, stress can be associated with a significantly stress-related alteration of urinary composition towards increased CaOx stone formation risk. The results obtained from the CIBD group allow for the first time a conclusive link between emotional stress and inflammatory activity on the one hand and inflammatory activity and metabolic risk constellation of CaOx stone formation on the other hand.

[Urinary tract infections and Urolithiasis]. / Harnwegsinfektionen und Urolithiasis.

The classic "infection stone" struvite is formed as a result of metabolic activity of urease-positive bacteria from alkaline urine with pH-values above 7.5. Due to improved infection diagnostics and antibiotic therapy, the occurrence of infection-related urinary stones in the western industrialized world decreases, despite the generally increasing prevalence rates of urolithiasis in these societies. Struvite is often associated with other mineral phases. These accessory mineral phases could indicate other, non-infection-related causes of urinary stone formation. Thus, mineral analysis is always recommended. Struvite stones as well as struvite encrustations on urinary tract implants are characterized by rapid growth. The rapid growth-related embedding of urease-positive bacteria in the crystalline material makes the urinary stone a persistent source of recurrent urinary tract infections. According to the German Society of Urology guidelines on urolithiasis, a patient with the diagnosis "infection stone" should be assigned to the "high-risk" patient group. Complete stone and debris removal, as well as a special metaphylaxis strategy are required to initiate successful stone therapy.

Bonn Risk Index based micromethod for assessing risk of urinary calcium oxalate stone formation.

PURPOSE: The Bonn Risk Index has been used to evaluate the risk of urinary calcium oxalate stone formation. According to the original method, risk should be determined based on a 200 ml urine sample taken from a 24-hour collection. We evaluated whether the Bonn Risk Index can also be effectively determined in small urine samples. MATERIALS AND METHODS: We studied 190 children and adolescents with nocturia and calcium oxalate urolithiasis. Initially Bonn Risk Index was determined according to the original method of Laube. Subsequently Bonn Risk Index was calculated using a computer program controlling a specially designed system to define the time point of induced crystallization based on consecutive urine samples of 1.5, 2.0 and 3.0 ml. RESULTS: No significant differences were found in Bonn Risk Index between values obtained from 200 ml samples and those based on the micromethod with urine samples of 2 and 3 ml. CONCLUSIONS: Assessment of risk of urinary calcium oxalate stone formation with Bonn Risk Index in small urine volumes, based on prototype equipment controlled by specialized computer software, is comparable to the original method. This finding facilitates the procedure and improves Bonn Risk Index determination in children.

[Coating with plasma-deposited functionalized diamond-like carbon to decrease encrustations on urological implants]. / Plasmadeponierte funktionalisierte Kohlenstoffschichten zur Minderung von Inkrustationen auf urologischen Implantaten.

The double-J stents used today for palliative artificial urinary diversion very often show extreme formation of encrustations, even a short time after implantation. Despite increased scientific material development, the complication rate has not really been strongly influenced. Grant-aided by the German Federal Ministry of Education and Research, we chose a new interdisciplinary and translational approach by coating standard stent materials with plasma-deposited amorphous diamond-like carbon. These stents show clearly reduced rates of encrustation in vitro. Ongoing clinical trials demonstrate a further enhancement of this effect in vivo. The underlying mechanisms are being investigated by extending the established in vitro model, thereby pushing research in this field to a new level.

[Extended metabolic diagnosis of urolithiasis]. / Erweiterte metabolische Diagnostik des Harnsteinleidens.

PURPOSE: In Germany, urolithiasis, with a frequency of 5 % and a continuously increasing incidence, must be considered as a widespread disease. Ever growing socio-economic expenses have become the focus of attention. The present treatment strategies provide only limited support for the practitioner in evaluating the often complex causes of urolithiasis and in assessing the chosen treatment. A successful treatment with minimal effort requires a general improvement of existing options in prophylaxis as well as metaphylaxis of urolithiasis. For this purpose, detailed examination and interpretation of a stone-former's urinary composition are essential. MATERIAL AND METHODS: The following two novel and significant methods with rapid and uncomplicated application procedures are presented: 1) The easy-to-perform and accurate determination of the calcium oxalate crystallisation risk from a urine sample using the BONN risk index (BRI) for the most frequently occurring stone type (75 %). 2) Consideration of the chemical depletion of lithogenic components in a urine sample due to in-vivo growing uroliths. This phenomenon, the so-called depletion effect, can be of considerable clinical relevance due to possible determination of false normal urinary parameters. RESULTS: This review article explains the theoretical background of these methods and the many applications of the novel methods in practice. CONCLUSIONS: New strategies in stone prevention can help to reduce the extent of urolithiasis in a patient. The BRI enables the practitioner to optimise patient treatment without major effort. Consideration of the stone growth-related alteration of composition improves the interpretation of urine analysis.

Occasional urinary tract infections and urinary depletion effect mask RTA and carbonate-apatite formation in a strong urinary stone former.

We report on a female patient with severe bilateral urolithiasis. A once-off stone analysis performed in the past revealed Mg-phosphate. Occasional UTIs were considered to be the sole cause of stone formation. To date, this assumption had not been checked thoroughly, while stone formation in the patient steadily increased. An inpatient metabolic and analytical work up was performed and stone-growth related urinary alteration was taken into account in urinalysis interpretation. No UTI. NH4Cl-loading test indicated RTA. CT revealed calculi in both kidneys. Carbonate-apatite (CAP) dominates stone composition. Computed urinary composition proximal to stones indicates hypercalciuria. In this patient, occasional UTIs (pH) masked the causes of urolithiasis. Lack of updated stone analysis (CAP), metabolic work up (RTA) and improved urinalysis interpretation (hypercalciuria) concealed the true causes of stone formation.

Oxalobacter formigenes: a potential tool for the treatment of primary hyperoxaluria type 1.

Primary hyperoxaluria is characterized by severe urolithiasis, nephrocalcinosis, and early renal failure. As treatment options are scarce, we aimed for a new therapeutic tool using colonic degradation of endogenous oxalate by Oxalobactor formigenes. Oxalobacter was orally administered for 4 weeks as frozen paste (IxOC-2) or as enteric-coated capsules (IxOC-3). Nine patients (five with normal renal function, one after liver-kidney transplantation, and three with renal failure) completed the IxOC-2 study. Seven patients (six with normal renal function and one after liver-kidney transplantation) completed the IxOC-3 study. Urinary oxalate or plasma oxalate in renal failure was determined at baseline, weekly during treatment and for a 2-week follow-up. The patients who showed >20% reduction both at the end of weeks 3 and 4 were considered as responders. Under IxOC-2, three out of five patients with normal renal function showed a 22-48% reduction of urinary oxalate. In addition, two renal failure patients experienced a significant reduction in plasma oxalate and amelioration of clinical symptoms. Under IxOC-3 treatment, four out of six patients with normal renal function responded with a reduction of urinary oxalate ranging from 38.5 to 92%. Although all subjects under IxOC-2 and 4 patients under IxOC-3 showed detectable levels of O. formigenes in stool during treatment, fecal recovery dropped directly at follow up, indicating only transient gastrointestinal-tract colonization. The preliminary data indicate that O. formigenes is safe, leads to a significant reduction of either urinary or plasma oxalate, and is a potential new treatment option for primary hyperoxaluria.

[Plasma-deposited carbon coating on urological indwelling catheters: Preventing formation of encrustations and consecutive complications]. / Plasmadeponierte Kohlenstoffbeschichtung auf urologischen Verweilkathetern: Vermeidung der Ausbildung von Inkrustationen und konsekutiven Komplikationen.

BACKGROUND: Any material placed in the urinary tract is susceptible to the formation of encrustations of crystalline bacterial biofilms. These biofilms cause severe complications in some cases. The strategies used so far for reduction of these complications by surface modifications of the implant material failed to show the expected results. PATIENTS AND METHODS: In this study, we investigated amorphous carbon coatings (a-C:H) for their ability to effectively reduce or to repress the progressive formation of infection-enhancing crystalline biofilms as new functional surface coatings. In nine patients suffering for several years from stenting, a-C:H-coated ureteral stents were tested in treatment attempts. The current replacement intervals amounted to a mean of 77 days; the principle cause for early replacement was massive stent encrustations associated with symptomatic urinary tract infections. RESULTS: In total, 20 coated ureteral stents were tested spanning indwelling times between 3 and 4 months. No stent-related complications occurred. In all cases extraordinarily facile handling, less pain during replacement, and markedly increased tolerance were observed. Symptomatic urinary tract infections were reduced by more than 50%. The stents remained virtually free of encrustations. CONCLUSION: a-C:H coatings are a novel strategy leading to an enhancement of long-term applicability of ureteral stents and catheters and to improved patient comfort.

[On the uncertainty of measurements illustrated by the BONN Risk Index]. / Uber die Unsicherheit von Messwerten am Beispiel des BONN-Risk-Index.

Every result of a measurement is subject to error. This error is inevitably caused by inaccuracies of the devices used and by environmental influences. For correct evaluation of a measurement result, this error must be estimated as exactly as possible. In kidney stone research and urolithiasis treatment, risk indices are applied to determine a patient's health status [e.g., AP(CaOx), RS(CaOx), BRI]. These operands (indices) combine important physical and chemical parameters of a certain disease pattern in a theoretically or empirically obtained mathematical formula. The index-related total error resulting from the single errors of the individual input parameters might be calculated with the Gaussian error propagation method. This method takes into account that individually determined parameters contribute differently to the total result. Due to this, summation of the various specific errors is insufficient. Instead, they must contribute to the total error depending on their individual weight. In medical borderline cases, knowledge of the value of this error may improve diagnosis since critical observation of an acquired value helps to avoid false interpretation. Using the BONN-Risk-Index (BRI) as an example for determination of the urinary calcium oxalate crystallization risk in native urine, the method of error calculation is demonstrated in detail and the advantages of including discussion of error in method development are discussed.

Diagnosis and metaphylaxis of stone disease. Consensus concept of the National Working Committee on Stone Disease for the upcoming German Urolithiasis Guideline.

This review draws the recent state of the art in metabolic diagnosis and metaphylaxis of stone disease. It is the basis for the consensus approval with the other medical societies and institutions in Germany involved in the guideline process of the new "Urolithiasis Guideline". The German Working Committee on Stone Disease reviewed critically the current literature in the field of urolithiasis-including the existing German and EAU-Guidelines as well as the Conference Book of the First International Consultation on Stone Disease. As far as possible the references were rated according to the EBM criteria. On this basis the expert group discussed all pathways and statements regarding the management of stone disease. The present review coincides with the consented guideline draft of the German Working Committee on Stone Disease. Occurrence of stone disease in the western world increases seriously. Modern lifestyle, dietary habits and overweight-problems of the affluent societies-emerge to be the important promoters of the "stone-boom" in the new millennium. This even affects children, whose stone prevalence is otherwise significantly less than that of adults. Criteria for the high risk group of stone formers were clearly defined. A diagnostic standard is formulated for the basic and the elaborate metabolic evaluation of a stone patient. Approximately 75% of all stone patients could anticipate stone recurrence with elementary reorientation of their lifestyle and dietary habits, summarized as general metaphylaxis. About 25% of the stone formers require additional pharmacological intervention to normalize their individual biochemical risk, precisely compiled for each stone type as specific metaphylaxis.

Problems in the investigation of urine from patients suffering from primary hyperoxaluria type 1.

Regular calculation of urinary crystallization risk indices in patients suffering from urolithiasis is a recommended measure for treatment adjustment. The more the patient experiences either extensive stone formation or an enhanced recurrence rate, the more important risk index calculations. In patients suffering from primary hyperoxaluria type 1 (PH1), both criteria are met. Different methods of risk determination are known. All strategies for measuring the calcium oxalate (CaOx) crystallization risk of a given urine principally determine this parameter from voided urine. This "bladder urine", however, has possibly passed stone material located in the urinary tract and thus may be depleted in lithogenic components. This is commonly the case for patients with PH1, who mostly experience a massive stone burden or severe nephrocalcinosis. Hence, the question arises as to whether we can adequately determine the crystallization risk in the urine of stone-bearing PH1-patients or not. Based on model calculations, we show that the determination of CaOx formation risk in PH1-patients requires knowledge of the restrictions in risk index interpretation: risk indices calculated from urinalysis (e.g. EQUIL) still indicate, even after strong in vivo stone formation, an enhanced but in fact strongly underestimated risk value. However, the outcome "enhanced" masks the patient's true risk situation. The BONN Risk Index (BRI), in contrast, discloses the process of extreme in vivo crystal formation. As determined, inter alia, from the urinary concentration of free ionized calcium ([Ca(2+)]), BRI approaches abnormally low values, as, in consequence of CaOx - formation, [Ca(2+)] tends to values close to zero. Thus, calculations of urinalysis-based risk indices alone are insufficient strategies for the quantification of a PH1 patient's CaOx crystallization risk.

[Misdiagnosis of urinalysis due to in vivo formation of urinary stones]. / Fehlinterpretation von Urinanalysen durch in vivo wachsende Harnsteine.

The occurrence of biochemically unaltered urinalyses in patients with severe recurrent stone formation is not a rare observation in practice. The possible reasons for that phenomenon are manifold. We show that stone growth-related urinary depletion of lithogenic constituents caused by acute growth of urinary calculi in vivo can be an important reason for the observed phenomenon. The described process which can strongly influence the urinary composition occurs in any stone-bearing patient. Thus, it is strongly recommended that stone-related alterations be taken into account when interpreting the urinalyses of these patients. Based on simplified model assumptions, the extent of the expected chemical depletion effect can be calculated for any stone patient's urine sample. In two easy-to-use nomograms, we have combined the key parameters which govern the process, allowing the user a fast and easy estimation.

[Monitoring of the treatment of calcium-oxalate stone formers with the Bonn-Risk-Index]. / Uberwachung des Behandlungserfolgs der bei Kalziumoxalatsteinmetaphylaxe mit dem Bonn-Risk-Index.

Cost-effective metaphylaxis and monitoring is becoming more and more focused in the treatment of urinary stones. Therefore, medical practitioners are asked to reduce the analytical efforts necessary for evaluation and to control the actual biochemical risk of stone formation in the patients. The most common strategy available is based on chemical urinalysis and the calculation of theoretically derived risk parameters. However, this covers--in the best case--the analysis of the most prominent low molecular urinary constituents. No information about the fraction of the important macromolecular urinary components is obtained. Crystallization experiments in unprepared, native urine samples, carried out according to the Bonn-Risk-Index approach (BRI), allow the determination of a more realistic measure of a urine's crystallization risk since the entire urinary composition influences the experimental result. As only two parameters have to be analyzed, the BRI is a fast and cost-effective risk evaluation method. The results show a high selectivity between stone-formers and non-stone-forming persons. The changes in the BRI-risk of three calcium oxalate stone-formers after a 1 week stay in our hospital are presented and discussed in detail. In one of these patients, a follow up examination was performed in order to control the therapy's success and, additionally, to obtain information about the patient's compliance with the therapy. During hospitalization, the patients received a standardized and "stone-neutral" diet. All persons showed a distinct decrease in their individual crystallization risk.