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Query: UMLS:C0392525 (nephrolithiasis)
 2,669 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies were performed on 12 patients with idiopathic hypercalciuria to evaluate the hypothesis that the acid load accompanying potassium acid phosphate would adversely affect renal calcium reabsorption and citrate excretion compared to the neutral form of the phosphate salt. During acute clearance studies, neutral phosphate (NP) led to a fall in FECa (2.2 +/- 0.6% to 0.8 +/- 0.1%, P less than 0.02) and no change in titratable acidity (TA) or net acid excretion (NAE). Acid phosphate (AP) did not reduce FECa acutely, and led to a rise in TA (22 +/- 4 to 62 +/- 6 muEq/min, P less than 0.02) and NAE (46 +/- 6 to 6 89 +/- 7 muEq/min, P less than 0.02). During chronic administration, AP resulted in higher urinary calcium excretion in both absorptive (187 +/- 29 vs. 141 +/- 18 mg/day, P less than 0.02) and renal hypercalciuric patients (233 +/- 24 vs. 173 +/- 190.02 mg/day, P less than 0.02). Also, TA and NAE were higher following AP, whereas citrate excretion was lower (375.4 +/- 64.6 vs. 633.4 +/- 28.8 mg/day, P less than 0.01). These data suggest that the reported ineffectiveness of AP in the therapy of nephrolithiasis may be related to the deleterious effects of the acid load on calcium and citrate metabolism.
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PMID:Differing effects of acid versus neutral phosphate therapy of hypercalciuria. 4 88

A patient is reported whose illness was characterized by chronic renal failure associated with persistent salt-wasting, chronic nephrolithiasis, and candiduria which was documented to be arising from the upper urinary tract. Intravenous amphotericin B was effective in eradicating candiduria. However, bilateral nephrectomy was ultimately performed which revealed extensive involvement of the renal parenchyma with classic caseating granulomas apparently related to renal candidiasis. Severe medullary erosion and tissue loss existed which appeared to result in disproportionate medullary destruction which was probably the most significant factor in explaining the patient's salt-losing state. The patient has since been satisfactorily managed with maintenance hemodialysis.
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PMID:Primary renal candidiasis with renal granulomata and salt-losing nephropathy. 113 Apr 31

Modern society adopts a highly ambiguous attitude towards foods of animal origin in human nutrition. Animal protein is of great biological value. However, the wealthy part of the world already consumes more than sufficient protein, which renders this value superfluous. On the other hand, a rich diet including a large share of animal products is suspect from the point of view of cardiovascular disease, cancer, osteoporosis and nephrolithiasis. The role of fat, protein, cholesterol, salt, calcium and a number of minor components is discussed. It is concluded that as far as fats are concerned, reduction is indicated. There is a large individual variability in response to salt and cholesterol as well as interactions with other components of the diet. A role of animal protein in affecting calcium metabolism is plausible, though not definitely established. Public health hazards due to contaminants are probably small compared with those caused by the major components.
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PMID:[Foods of animal origin and public health (author's transl)]. 722 3

In order to assess the influence of dietary protein and salt intake on urinary calcium excretion in calcium stone formers, we simultaneously determined 24 hour urinary excretion of Urea (UU) and sodium (UNa) together with that of calcium (UCa) in 184 patients (112 males) with idiopathic calcium nephrolithiasis studied on free diet. Mean (+/- SEM) values expressed as mmol/kg BW/day of both UU and UNa were higher in hypercalciuric (UCa > or = 0.1 mmol/kg/d, mean 0.15 +/- 0.01) male patients, respectively 6.63 +/- 0.25 and 2.71 +/- 0.13, than in normocalciuric males, respectively 5.33 +/- 0.22 (p < 0.001) and 2.36 +/- 0.15 (p = 0.06), while the latter did not differ from healthy controls. Similar findings were made in female stone formers. Linear regression analysis on the whole series showed a positive but weak correlation between UU and UCa (r = 0.47, p < 0.001) and between UNa and UC a (r = 0.33, p < 0.001), but the slope of the relation UCa/UU was increased only in hypercalciurics, whereas it did not differ between normocalciurics and controls. By multiple regression analysis, variations of UU and UNa altogether accounted only for 22% of variation in UCa. We conclude that in both sexes hypercalciuric stone formers have a higher protein and sodium intake than normocalciurics, and for a given urinary urea output, their mean urinary calcium excretion is higher, thus suggesting that hypercalciuric stone formers are electively sensitive to the hypercalciuric effect of high protein intake.
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PMID:[Correlation between protein and sodium intake and calciuria in calcium lithiasis]. 814 87

Nephrolithiasis is uncommon after kidney transplantation. However, calcium (Ca) supplementation, which has been proposed as a treatment of post-transplant osteopenia, might increase calciuria and bolster Ca stone formation. Therefore, in 24-hour urine of 82 normocalcemic long-term renal transplant recipients (RT) and in 82 healthy subjects (HS), we assessed some Ca nephrolithiasis risk factors and the Ca-salt saturation estimated by the ion-activity product index (AP) and relative supersaturation (RS). In RT, calciuria was lower (mean +/- SD, 3.20 +/- 2.25 vs. 4.61 +/- 1.71 mmol/day; P < 0.001), urinary volume higher (2.41 +/- 0.83 vs. 1.39 +/- 0.53 liter/day; P < 0.001), oxaluria higher (419 +/- 191 vs. 311 +/- 79 mumol/day; P < 0.001) and citraturia lower (1.40 +/- 1.36 vs. 3.77 +/- 1.36 mmol/day; P < 0.001) than in HS. As a result, Ca-oxalate supersaturation was lower in RT than HS (AP, 1.07 +/- 0.69 vs. 2.07 +/- 1.13, P < 0.001; and RS, 0.62 +/- 0.26 vs. 0.94 +/- 0.21, P < 0.001), and was similar in subgroups of RT (N = 37) and HS (N = 37) matched for urinary volume, demonstrating that even without any larger urinary volume, Ca-oxalate saturation was not higher in RT than HS, and suggesting that opposite changes in Ca and oxalate in RT likely canceled their effects on lithogenic risk. In RT which had similar urinary pH and phosphate (P) than HS, Ca-P supersaturation was lower than in HS for brushite (AP, 3.25 +/- 6.67 vs. 6.01 +/- 4.85, P < 0.001; RS, -0.33 +/- 0.76 vs. 0.48 +/- 0.53, P < 0.001) and octacalcium phosphate (RS, -0.95 +/- 0.72 vs. 0.21 +/- 0.85, P < 0.001), and similar for apatite. Finally, fasting calciuria and calciuric response to a single oral Ca load were similar in RT (N = 19) and HS (N = 8). Together, these results argue strongly against a higher risk of Ca stone formation in RT than HS, even in case of Ca supplementation.
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PMID:Lack of increased urinary calcium-oxalate supersaturation in long-term kidney transplant recipients. 906 14

The primary care physician has a responsibility not only to recognize and treat acute stone passage but to ensure that the patient with recurrent stones has metabolic evaluation and appropriate preventive care. Renal colic is typically severe, radiates to the groin, is associated with hematuria, and may cause ileus. About 90% of stones that cause renal colic pass spontaneously. The patient with acute renal colic should be treated with fluids and analgesics and should strain the urine to recover stone for analysis. Highgrade obstruction or failure of oral analgesics to relieve pain may require hospitalization; a urinary tract infection in the setting of an obstruction is a urologic emergency requiring immediate drainage, usually with a ureteral stent. Several approaches are available when stones do not pass spontaneously, including extracorporeal shock wave lithotripsy, percutaneous lithotripsy, and ureteroscopic laser lithotripsy. Calcium stone disease has a lifetime prevalence of 10% in men and causes significant morbidity. Renal failure is unusual. Stone types include calcium oxalate, uric acid, struvite, and cystine. Stone analysis is particularly important when a noncalcareous constituent is identified. The majority of patients with nephrolithiasis will have recurrence, so prevention is a high priority. High fluid intake is a mainstay of prevention. Metabolic evaluation will indicate other appropriate preventive measures, which may include dietary salt and protein restriction, and use of thiazide diuretics, neutral phosphate, potassium citrate, allopurinol, and magnesium salts. Dietary calcium restriction may worsen oxaluria and negative calcium balance (osteoporosis).
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PMID:Nephrolithiasis: acute management and prevention. 965 69

Nephrolithiasis is a common disorder and a significant problem because of incidence, recurrence and severe consequences. Stone disease is a surgical as well as a medical problem. Major progress has been made recently in understanding the pathophysiological disturbances responsible for stone formation as well as in the techniques of stone removal. The introduction of extracorporeal shock wave lithotripsy has considerably reduced the need for surgery. Improvements in methods of kidney stone removal have not diminished the need for the application of an effective prophylactic program. The internist should take a complete history of stone events (number, composition, location and outcome of stone event), family history of stones, dietary habits (focusing on the consumption of animal protein, salt and dairy products), medications and physical examination. Radiopaque stones should be documented by plane X-ray films. Ultrasonography should be used to image calculi that are nonopaque, and to easily distinguish them from masses such as tumour or blood clot. Computed tomography is also an excellent method for imaging nonopaque renal calculi but higher cost and radiation exposure are disadvantages [2]. Crystallographic analysis is the essential diagnostic procedure. If available, previous stones should also be examined. "In stone disease, everything is measurement. What the laboratory cannot tell you, you will not know; what it tells you in error, you will not correct by using your instincts, your medical experience, or your art [3]". Reliable diagnostic protocols are available for the identification of different causes of stones. The complexity of protocols depend on the severity of nephrolithiasis. Patients with a single stone episode undergo simple protocol, and extensive detailed protocol is used for patients with recurrent stone disease, or patients at increased risk. Simple protocol, besides the already mentioned history of stone events, radiographic investigation and crystallographic analysis, includes serum urea, creatinine, uric acid, sodium, calcium, phosphorus and protein levels, urinary pH and volume, urine samples for culture and urinary calcium, uric acid, oxalate and citrate. Extensive metabolic evaluation includes simple protocol, determination of serum levels of alkaline phosphatase, parathyroid hormone, thyroxin, magnesium. A 24-h collection of urine specimen is analysed for urea, creatinine, uric acid, calcium, phosphate, sodium, magnesium, oxalate and citrate. Extensive protocol includes specialized evaluation tests [5]. Urinary acidification test is important for detecting distal renal tubular acidosis. Two 24-h urine specimens are collected while the patient is on the regular diet. The patient is then placed on a restricted diet (400 mg of calcium and 100 mEq of sodium) for a week, and another 24-h urine sample is collected. After that fasting and calcium load tests are performed (Sheme 1). Fasting urinary calcium is used to detect renal calcium leak, and calciuric response to oral calcium load provides an indirect measure of intestinal calcium absorption. Diagnostic criteria for major forms of stone disease [8] are presented in Table 1. There are some still unsolved questions: does time after passage of stones or urological intervention influence the frequency of urine abnormalities that can be detected; are there differences in 24-h urine composition between weekdays and weekends: what is the prevalence of the most important urinary risk factors of recurrent idiopathic calcium nephrolithiasis: do male patients differ from females with respect to urinary risk factors or recurrent idiopathic calcium nephrolithiasis? [7].
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PMID:[Functional evaluation in patients with kidney calculi]. 986 14

Despite the risk of kidney damage, lithotripsy is the usual way of treating calcium oxalate (CaOx) stones, the most common type of nephrolithiasis, because no effective chemolytic agents are available. However, the search of new calcium chelators, less toxic than the current ones, continues, and some of them could be tested in experimental models of nephrolithiasis, after their ability of dissolving CaOx crystals is verified. In this connection, we developed a simple assay that requires only inexpensive equipment available in most laboratories for the screening of substances potentially capable of dissolving CaOx crystals. In particular, we decided to investigate whether substances previously shown to inhibit CaOx precipitation were also capable of dissolving this salt. Briefly, CaOx tablets of highly reproducible weight (4.55 +/- 0.07 mg) were prepared by spinning, at high speed (16,000 g), microcentrifuge tubes in which 500 microl aliquots of 0.1 M sodium oxalate and 0.1 M calcium chloride at pH 6 were added. When these tablets were incubated overnight with solutions at different concentrations of EDTA, sodium citrate, manganese chloride, sodium sulfate, sodium chloride, malic acid, succinic acid and gluconic acid, a significant dissolving activity was observed for EDTA ( approximately 25% at 0.25 M), sodium citrate ( approximately 30% at 1 M) and manganese chloride ( approximately 20% at 0.5 M). A good linear correlation (r2 = 0.84, p < 0.05) was found between the affinity for calcium and the activity of EDTA, sodium citrate, sodium sulfate, malic acid, succinic acid and gluconic acid, indicating that these compounds act mainly by chelating the calcium ion. Instead, manganese was supposed to act by interacting with the oxalate ion.
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PMID:Development of an in vitro assay for the screening of substances capable of dissolving calcium oxalate crystals. 1036 51

The first episode of nephrolithiasis provides an opportunity to advise patients about measures for preventing future stones. Low fluid intake and excessive intake of protein, salt and oxalate are important modifiable risk factors for kidney stones. Calcium restriction is not useful and may potentiate osteoporosis. Diseases such as hyperparathyroidism, sarcoidosis and renal tubular acidosis should be considered in patients with nephrolithiasis. A 24-hour urine collection with measurement of the important analytes is usually reserved for use in patients with recurrent stone formation. In these patients, the major urinary risk factors include hypercalciuria, hyperoxaluria, hypocitraturia and hyperuricosuria. Effective preventive and treatment measures include thiazide therapy to lower the urinary calcium level, citrate supplementation to increase the urinary citrate level and, sometimes, allopurinol therapy to lower uric acid excretion. Uric acid stones are most often treated with citrate supplementation. Data now support the cost-effectiveness of evaluation and treatment of patients with recurrent stones.
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PMID:Prevention of recurrent nephrolithiasis. 1059 18

The studies involved 20 children with idiopathic hypercalciuria (IH). An influence of urinary sodium excretion, and reflection of its intake, on urinary calcium excretion has been assessed. Children who were normocalciuric had significancy lower values of urine sodium excretion when compared with those with persisting hypercalciuria. The main factor responsible for hypercalciuria in children seemed to be urine sodium excretion. As urine sodium excretion reflects its intake, reduction dietary salt, rather than calcium intake, may be useful in the management of children with hypercalciuria and nephrolithiasis.
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PMID:[Importance of dietary sodium in the hypercalciuria syndrome and nephrolithiasis]. 1089 99


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