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

One hundred fourteen nondialyzed azotemic adult patients (creatinine connentration 1.2 to 17.6 mg/dl), 78 stable renal transplant recipients (creatinine less than 1.9 mg/dl), 50 patients with idiopathic nephrolithiasis, 36 patients with surgically proven primary hyperparathyroidism, and 62 normal volunteers were studied with simultaneous serum ionized calcium, total calcium, parathyroid hormone (PTH), phosphorus, and creatinine measurements. Ionized calcium could not be reliably predicted from total calcium. Although in all patient groups values for serum ionized calcium correlated significantly with those for total calcium, the scatter around the regression line was such that a direct interpretation was not precise. With respect to reference values, significant differnces were found between ionized and total calcium in 26% of all studied patients. When compared with total serum calcium, ionized calcium appeared to be a more sensitive index of calcium metabolism. All correlations with ionized calcium had a higher r value compared with those with total serum calcium. Two findings were particularly rewarding. In patients with chronic renal failure, serum PTH showed a negative correlation with serum ionized calcium, indicating that the latter may have been largely responsible for the secondary increase in PTH; in patients after a successful transplant, serum PTH showed a positive correlation with serum ionized calcium, indicating that in the presence of normal kidney function the previously hypertrophied parathyroid glands may be largely responsible for the daily study of a large number of specimens, determinations of serum ionized calcium should be encouraged in all patients suspected of having abnormalities of renal calcium metabolism.
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PMID:Comparative studies of total and ionized serum calcium values in normal subjects and patients with renal disorders. 699 43

The exposure of rats to hypokinesia and a phosphorus-enriched diet (Ca : P = 1:3) was accompanied by hypocalciemia, hyperphosphatemia, calcium losses from bones and formation of calcificates in the kidneys. The decrease of the phosphorus content in the diet (Ca : P = 1:0.5--1:1) prevented these disorders. The administration of 1 alpha OHD3 at a dose of 0.025 microgram/day arrested hypokinesia-associated hypocalciemia and bone changes. The administration of 1 alpha OHD3 together with a high phosphorus consumption enhanced nephrolithiasis and induced aortal mediacalcinosis in hypokinetic rats. These data indicate that phosphorus consumption should be reduced in order to prevent disorders in phosphorus-calcium metabolism during hypokinesia. They also suggest that administration of 1 alpha OHD3 may be hazardous in case of excessive phosphorus consumption.
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PMID:[Effect of 1 alpha-hydroxycholecalciferol and various dietary phosphorus levels on phosphorus and calcium metabolic indices in rats during hypokinesia]. 707 35

Patients with ileal disease have increased absorption of dietary oxalate, hyperoxaluria, and an increased incidence of nephrolithiasis. Patients with steatorrhea of varying etiologies also have hyperoxaluria. To determine whether steatorrhea per se is associated with nephrolithiasis, we reviewed the charts of all adult patients who had a 72-hr fecal fat analysis from 1968 to 1978. The 159 patients with steatorrhea were compared to 162 patients without steatorrhea. The two groups were comparable in age, sex, urine specific gravity, and serum uric acid and phosphorus; serum calcium was slightly less in the steatorrhea group (8.7 +/- 0.1 vs 9.0 +/- 0.1, P less than 0.02). Although 19 patients with steatorrhea had nephrolithiasis compared to 7 control patients (P = 0.01), 15 of these 19 patients had ileal disease and only 4 of the 118 patients with steatorrhea but without ileal disease had stones. Categorical data analysis revealed that steatorrhea, diarrhea (stool weight greater than 225 g/day), male sex, and ileal disease were significantly associated with nephrolithiasis with a relative risk of 3.0, 2.7, 3.1, and 8.0, respectively. When patients without ileal disease were analyzed separately, however, steatorrhea, diarrhea, and sex were no longer risk factors. In contrast, in patients with ileal disease the incidence of nephrolithiasis increased with the severity of steatorrhea. The relative risk of nephrolithiasis in male patients with ileal disease and fecal fat greater than 20 g/day was 26.3 (P less than 0.01). Thus, the presence of both ileal disease and steatorrhea greatly increases the risk of nephrolithiasis; however, neither steatorrhea alone nor ileal disease alone are risk factors for nephrolithiasis.
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PMID:Increased risk of nephrolithiasis in patients with steatorrhea. 707 27

Three children with primary hyperparathyroidism, confirmed at operation, are reported. The generalized skeletal changes with pathological fractures are leading in two of them, necessitating a long-term orthopedic treatment. Big solitary adenomas were found at operation. The disease, in the third child, had the course of nephrolithiasis. Hyperplasia of all four parathyroid bodies with light cells was established at operation. The biochemical deviations are typical in all three children undergone operations: hypercalcemia, hypophosphatemia, elevated alkaline phosphatase with increased excretion of calcium and phosphorus in urine.
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PMID:[Primary hyperparathyroidism in childhood and adolescence]. 710 84

The metabolic picture of 32 patients with surgically proven primary hyperparathyroidism presenting with renal stones was compared with that of 37 patients without stones. Between stone-forming and nonstone-forming groups, there was no significant difference in serum 1,25-dihydroxyvitamin D [6.82 +/- 2.62 vs. 6.22 +/- 2.33 ng/dl (mean +/- SD); P greater than 0.05], fractional (intestinal) calcium absorption (0.726 +/- 0.141 vs. 0.690 +/- 0.120), urinary calcium (299 +/- 139 vs. 284 +/- 144 mg/day), serum calcium, phosphorus, and parathyroid hormone, or bone density. Similarly, no differences were found between 29 patients presenting with stones alone and 9 presenting with bone disease alone with respect to the above measures. Moreover, urinary environment was typically supersaturated with respect to stone-forming salts regardless of the presence of stones. The results indicate that there is no unique pathophysiological background for the nephrolithiasis of primary hyperparathyroidism.
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PMID:A lack of unique pathophysiologic background for nephrolithiasis of primary hyperparathyroidism. 726 39

The effects of total sunlight deprivation on urinary risk factors for nephrolithiasis and vitamin D metabolism were studied in 20 healthy male subjects. Blood and 24-h urine samples were collected before submarine deployment and 68 days later while still at sea. No subject received sunlight exposure during the test interval. Significant decreases in daily urinary excretion of calcium, uric acid, sodium, sulfate, and phosphorus were found. The relative supersaturation ratio of monosodium urate also fell. There was no change in urinary citrate or urine volume. Mean serum levels of 25-hydroxyvitamin D [25(OH)D] declined from 31 to 19 pg/ml (P < 0.0001), parathyroid hormone increased from 22 to 30 pg/ml (P < 0.0001), and osteocalcin (GLA) increased from 2.7 to 3.3 ng/ml (P = 0.005). Mean serum levels of 1,25 dihydroxy-vitamin D were unchanged. Four subjects had 25(OH)D levels below 10 ng/ml by the end of the submarine patrol. These findings suggest that exposure to the submarine environment produces physiologic changes that decrease the risk for renal stone formation. The data are consistent with the role of vitamin D metabolism in sunlight deprivation and demonstrate that compensatory mechanisms are well established within 68 days.
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PMID:Effects of the submarine environment on renal-stone risk factors and vitamin D metabolism. 763 76

Calcium oxalate nephrolithiasis is a common syndrome that recurs and may be complicated by infection, obstruction, bleeding, and rarely, impairment in renal function. The formation of Ca oxalate stones depends on the state of urinary supersaturation with respect to Ca and oxalate and the action of urinary inhibitors of crystal nucleation, aggregation, and growth. Idiopathic hypercalciuria is the most common cause of Ca oxalate stones and is characterized by hypercalciuria, normocalcemia, and intestinal Ca hyperabsorption with or without elevated serum 1,25(OH)2D3 levels in the absence of other known causes of hypercalciuria. Current diagnostic evaluation of recurrent Ca oxalate nephrolithiasis should be conducted while the patients follow their usual diets and includes the following: 1. Analysis of stone composition by polarization microscopy. 2. Measurement of serum Ca, phosphate, uric acid, 1,25(OH)2D3, and creatinine. 3. Twenty-four-hour urine collection for an analysis of volume, pH, and excretion of Ca, phosphorus, magnesium, uric acid, citrate, sodium, oxalate, and creatinine. Therapy to prevent stone recurrence is designed to reduce urinary supersaturation of Ca oxalate by increasing urine volume, reducing urine Ca to below 200 mg/24 hr with thiazide, maintaining dietary Ca intake at 600 to 800 mg/day, and adding potassium citrate if urine citrate levels are reduced. If elevated, urine oxalate excretion can be reduced by dietary oxalate restriction. Stones less than 2 cm in diameter located in the renal parenchyma or upper urinary tract can be fragmented with ESWL, whereas larger stones or those in the lower urinary tract should be removed by either percutaneous nephrolithotomy or ureteroscopic procedures.
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PMID:Diagnosis and treatment of calcium kidney stones. 767 Oct 93

A total of 19 patients with active nephrolithiasis, 14 patients with non-active nephrolithiasis and 17 healthy subjects were examined under standardized intake of calcium, phosphorus, purine and protein. In patients with both active and non-active renal stone disease the following abnormalities were found: elevated plasma levels of PTH and osteocalcin, increased activity of the bone isozyme of alkaline phosphatase, low plasma levels of phosphate and increased urinary excretion of calcium and oxalic acid. These abnormalities were more marked in patients with active than non-active nephrolithiasis. No correlation was found between plasma PTH levels and parameters of bone turnover as well as calciuria and oxaluria. Results presented in this paper suggest that (a) Smith's criteria of active renal stone disease are of minor pathogenetic and therapeutic value and (b) patients with active nephrolithiasis differ from non-active renal stone formers by more elevated oxaluria and markers of bone turnover and more marked abnormalities in calcium-phosphate metabolism related parameters.
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PMID:Markers of bone turnover in patients with nephrolithiasis. 941 56

Twenty male Wistar rats, weighing 150 g, were placed in metabolic cages on a 30% sucrose diet for 7 days, before allocation to two groups: a control group (n = 5) and a lactose group (n = 15). They received respectively a 30% sucrose diet or a 30% lactose diet for 8 weeks, each containing 0.67% calcium and 0.38% phosphorus. After 4 (T1) and 8 (T2) weeks, the serum calcium (Ca) and citrate levels were significantly (P < 0.01) higher in rats fed the lactose diet. Serum alkaline phosphatase activity was increased in the lactose group (P < 0.01) at T1 and T2. The lactose-rich diet induced an increase in urinary Ca excretion at T1 and T2; citrate excretion was only enhanced at T2 (P < 0.001). No difference between the two groups was observed in urinary oxalate (Ox) excretion or creatinine clearance. Crystalluria analysis revealed a marked number (>300/mm3 at T1 and T2) of calcium oxalate dihydrate crystals (COD) in rats fed the lactose-rich diet, whereas no COD crystals were observed in sucrose-fed control rats at any time point. The formation of COD crystals in lactose-fed rats was related to an increase in calcium oxalate (CaOx) product (pCaOx), which was respectively 12.6 vs 3.9 at T1 and 10.5 vs 1.8 at T2, and an increase in CaOx ratio (Ca/Ox), which was 99.1 vs 7.5 and 67.5 vs 18.5 at T1 and T2, respectively. The high pCaOx and Ca/Ox ratios in the lactose group were due to hypercalciuria, in agreement with the number and the type of crystals. The present experimental model confirms that the ingestion of a 30% lactose diet increases urinary Ca excretion without changing urinary Ox excretion and shows for the first time that it induces a stable and marked crystalluria composed of COD. Such a non-nephrotoxic and stable model is of interest for the study of CaOx crystal formation secondary to hypercalciuria, and thus afterwards eventually for CaOx nephrolithiasis.
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PMID:A stable animal model of diet-induced calcium oxalate crystalluria. 953 98

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


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