Recurrence rates of urinary calculi according to stone composition and morphology.

Few studies have examined the relative risk of recurrence of different stone types. The object of the present study was to evaluate the tendency for stone recurrence as a function of major mineral composition of the stones and morphological characteristics of the stones. This study was carried out using 38,274 stones for which we had data available to specify if the stone was from the first or a subsequent urinary stone episode.

Drug-Induced Kidney Stones and Crystalline Nephropathy: Pathophysiology, Prevention and Treatment.

Drug-induced calculi represent 1-2% of all renal calculi. The drugs reported to produce calculi may be divided into two groups. The first one includes poorly soluble drugs with high urine excretion that favour crystallisation in the urine.

Validation of Surrogates of Urine Osmolality in Population Studies.

Background: The importance of vasopressin and/or urine concentration in various kidney, cardiovascular, and metabolic diseases has been emphasized recently. Due to technical constraints, urine osmolality (Uosm), a direct reflect of urinary concentrating activity, is rarely measured in epidemiologic studies.

Methods: We analyzed 2 possible surrogates of Uosm in 4 large population-based cohorts (total n = 4,247) and in patients with chronic kidney disease (CKD, n = 146).

Comparison between copeptin and vasopressin in a population from the community and in people with chronic kidney disease.

Context: Vasopressin plays a central role in water homeostasis but it has also been recognized to be associated with adverse effects in several chronic diseases. Recently, copeptin has been increasingly used as a surrogate for vasopressin, as they are co-secreted, and copeptin is easier to measure. However, the relationship between plasma concentrations of copeptin (P(cop)) and vasopressin (P(vp)) has only been studied in relatively small numbers of selected people.

The pathogenesis of Randall's plaque: a papilla cartography of Ca compounds through an ex vivo investigation based on XANES spectroscopy.

At the surface of attached kidney stones, a particular deposit termed Randall's plaque (RP) serves as a nucleus. This structural particularity as well as other major public health problems such as diabetes type-2 may explain the dramatic increase in urolithiasis now affecting up to 20% of the population in the industrialized countries. Regarding the chemical composition, even if other phosphate phases such as whitlockite or brushite can be found as minor components (less than 5%), calcium phosphate apatite as well as amorphous carbonated calcium phosphate (ACCP) are the major components of most RPs.

Stone formation and pregnancy: pathophysiological insights gained from morphoconstitutional stone analysis.

Purpose: We examined whether stone composition in pregnant women reflects peculiar pathophysiological conditions.

Materials And Methods: We analyzed in detail the composition of stones from 244 pregnant women 17 to 44 years old and from 5,712 nonpregnant women in the same age range, as recorded between January 1991 and December 2007. Clinical features were also recorded.

Nonprogressive kidney dysfunction and outcomes in older adults with chronic kidney disease.

Objectives: To determine whether a subgroup of patients with severe but nonprogressive renal dysfunction exist and to characterize this subgroup.

Design: Retrospective longitudinal monocentric cohort study.

Setting: Nephrology clinic for chronic kidney disease (CKD).

Revisiting the localisation of Zn(2+) cations sorbed on pathological apatite calcifications made through X-ray absorption spectroscopy.

The role of oligo-elements such as Zn in the genesis of pathological calcifications is widely debated in the literature. An essential element of discussion is given by their localisation either at the surface or within the Ca apatite crystalline network. To determine the localisation, X-ray absorption experiments have been performed at SOLEIL.

Relationships between carbonation rate of carbapatite and morphologic characteristics of calcium phosphate stones and etiology.

Objectives: To examine the significance of the carbonation rate (CR) in carbonated apatite (carbapatite [CA]) stones and its relationships with the morphologic characteristics of CA and etiology. CA stones without struvite can result from metabolic disorders or urinary tract infection, but the latter etiology is still debated. Infection stones caused by urea-splitting bacteria are made of CA admixed with struvite and exhibit a high CO(3)(2-)/PO(4)(3-) ratio (CR).

Very first tests on SOLEIL regarding the Zn environment in pathological calcifications made of apatite determined by X-ray absorption spectroscopy.

This very first report of an X-ray absorption spectroscopy experiment at Synchrotron SOLEIL is part of a long-term study dedicated to pathological calcifications. Such biological entities composed of various inorganic and/or organic compounds also contain trace elements. In the case of urinary calculi, different papers already published have pointed out that these oligo-elements may promote or inhibit crystal nucleation as well as growth of mineral.

[Inherited monogenic kidney stone diseases: recent diagnostic and therapeutic advances].

Hereditary monogenic kidney stone diseases are rare diseases, since they account for nearly 2% of nephrolithiasis cases in adults and 10% in children. Most of them are severe, because they frequently are associated with nephrocalcinosis and lead to progressive impairment of renal function unless an early and appropriate etiologic treatment is instituted. Unfortunately, treatment is often lacking or started too late since they are often misdiagnosed or overlooked.

Diabetes and nephrolithiasis.

Type 2 diabetes is associated with an increased risk of nephrolithiasis, specifically in the form of uric acid (UA) nephrolithiasis. Diabetic patients who produce uric stones exhibit a low urine pH, the key factor of UA crystallization. Production of such acidic urine appears to result from the insulin-resistant state characteristic of diabetes mellitus.

[Difference in urine concentration according to gender and ethnicity: possible involvement in the different susceptibility to various renal and cardiovascular diseases].

Men and African-Americans are known to be at greater risk of urolithiasis and cardiovascular and renal diseases than women and Caucasians. Previous studies suggest that the antidiuretic effects of vasopressin and/or a greater urine concentration are associated with the rate of progression of these diseases. The present review addresses possible sex and ethnic-related differences in urine volume and osmolality which could participate in this male and black higher predominance.

[Encrusted pyelitis: early diagnosis facilitates conservative management].

Diagnosis of encrusted pyelitis in predisposed patients is difficult. The bacteriology laboratory must be specifically asked to perform the appropriate tests. Computed tomography without injection is very important for diagnosis and follow-up.

[Nephrolithiasis-induced ESRD: frequency, causes and prevention].

Nephrolithiasis still remains a too frequent - and under-appreciated - cause of end-stage renal disease (ESRD), and this is all the most unfortunate since such an untoward course is now preventable in most cases. Among 1391 patients who started maintenance dialysis at Necker hospital between 1989 and 2000, nephrolithiasis was identified as the cause of ESRD in 45 of them, an overall prevalence of 3.2%.

Type 2 diabetes increases the risk for uric acid stones.

An increased prevalence of nephrolithiasis has been reported in patients with diabetes. Because insulin resistance, characteristic of the metabolic syndrome and type 2 diabetes, results in lower urine pH through impaired kidney ammoniagenesis and because a low urine pH is the main factor of uric acid (UA) stone formation, it was hypothesized that type 2 diabetes should favor the formation of UA stones. Therefore, the distribution of the main stone components was analyzed in a series of 2464 calculi from 272 (11%) patients with type 2 diabetes and 2192 without type 2 diabetes.

Influence of body size on urinary stone composition in men and women.

A larger body size has been shown to be associated with increased excretion of urinary lithogenic solutes, and an increased risk of nephrolithiasis has been reported in overweight patients. However, the type of stones produced in these subjects has not been ascertained. Based on a large series of calculi, we examined the relationship between body size and the composition of stones, in order to assess which type of stone is predominantly favoured by overweight.

[Continued late referral of patients with chronic kidney disease. Causes, consequences, and approaches to improvement].

Objectives: Efforts in recent years have aimed at increasing physicians' awareness of the frequent and harmful consequences of late referral to nephrologists of patients with chronic kidney disease (CKD), shown in repeated concordant studies. We sought to determine whether these efforts have led to improved predialysis care of these patients.

Methods: This study included all 1391 consecutive patients who began maintenance dialysis at Necker Hospital between January 1989 and December 2000.

Prediction model of coronary heart disease in patients with chronic kidney disease: role of plasma fibrinogen as a new prognostic variable.

Background: The Framingham-Anderson (FA) risk equation can predict coronary heart disease (CHD) risk in the general population. However, this formula's validity in predicting CHD risk in chronic kidney disease (CKD) patients is not extensively evaluated.

Methods: In a group of 96 patients with CKD stage 2 to 4, free of CHD at the time of the start of follow-up, and prospectively followed for 4 to 12 years (7.

Serial crystalluria determination and the risk of recurrence in calcium stone formers.

Background: Urinary crystal precipitation is the necessary initial step in kidney stone formation. However, clinical relevance of crystalluria in the evaluation of stone formers is disputed.

Methods: We serially determined crystalluria in first-voided morning urine samples, together with full 24-hour urine biochemistry, in 181 patients with idiopathic calcium nephrolithiasis who had formed at least one calcium-oxalate stone and were followed for at least 3 years under our care.

Advanced oxidation protein products as risk factors for atherosclerotic cardiovascular events in nondiabetic predialysis patients.

Background: Inflammation and oxidative stress are established risk factors for atherosclerosis, but whether they contribute to the accelerated atherogenesis associated with chronic kidney disease (CKD) remains to be assessed at the predialysis stage.

Methods: We prospectively examined the relationship between plasma levels of C-reactive protein (CRP), fibrinogen, and advanced oxidation protein products (AOPPs), as selected markers of inflammation and oxidative stress, and incident first occlusive atherosclerotic cardiovascular (CV) events (ASCVEs) in a single-center cohort of 80 uremic predialysis patients without diabetes with a creatinine clearance ranging from 20 to 40 mL/min/1.73 m2 .