Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0451641 (urolithiasis)
 3,973 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Zellweger spectrum disorders (ZSDs) are characterized by a generalized loss of peroxisomal functions caused by deficient peroxisomal assembly. Clinical presentation and survival are heterogeneous. Although most peroxisomal enzymes are unstable in the cytosol of peroxisome-deficient cells of ZSD patients, a few enzymes remain stable among which alanine:glyoxylate aminotransferase (AGT). Its deficiency causes primary hyperoxaluria type 1 (PH1, MIM 259900), an inborn error of glyoxylate metabolism characterized by hyperoxaluria, nephrocalcinosis, and renal insufficiency. Despite the normal level of AGT activity in ZSD patients, hyperoxaluria has been reported in several ZSD patients. We observed the unexpected occurrence of renal stones in a cohort of ZSD patients. This led us to perform a study in this cohort to determine the prevalence of hyperoxaluria in ZSDs and to find clinically relevant clues that correlate with the urinary oxalate load. We reviewed medical charts of 31 Dutch ZSD patients with prolonged survival (>1 year). Urinary oxalate excretion was assessed in 23 and glycolate in 22 patients. Hyperoxaluria was present in 19 (83%), and hyperglycolic aciduria in 14 (64%). Pyridoxine treatment in six patients did not reduce the oxalate excretion as in some PH1 patients. Renal involvement with urolithiasis and nephrocalcinosis was present in five of which one developed end-stage renal disease. The presence of hyperoxaluria, potentially leading to severe renal involvement, was statistically significant correlated with the severity of neurological dysfunction. ZSD patients should be screened by urinalysis for hyperoxaluria and renal ultrasound for nephrocalcinosis in order to take timely measures to prevent renal insufficiency.
 ...
PMID:High incidence of hyperoxaluria in generalized peroxisomal disorders. 1662 44

The review is dedicated to ultrasonography of the upper urinary tract in patients with nephrolithiasis. Ultrasonographic semiotics of urolithiasis, the ability of unlrasonography to detect nephrolithiasis, and methods of the optimization of these diagnostic techniques in patients with upper urinary tract calculi are covered. The author discusses difficulties that may be faced while differentiating between nephrolithiasis and such conditions as spongious kidney, nephrocalcinosis, calcification of renal papillae, cysts, tumors, and vascular walls, as well as other kinds of renal calcification, associated with ultrasonographic acoustic path phenomenon. The advantages and disadvantages of ultrasonography in cases of X-ray urolithiasis are evaluated in the paper. The article describes hardships in ultrasound visualization of ureteral calculi causing acute upper urinary tract obstruction, and the ways of getting over them.
 ...
PMID:[Ultrasound diagnostics of upper urinary tract calculi]. 1675 27

Genetic disorders of mineral metabolism cause urolithiasis, renal disease, and osteodystrophy. Most are rare, such that the full spectrum of clinical expression is difficult to appreciate. Diagnosis is further complicated by overlap of clinical features. Dent's disease and primary hyperoxaluria, inherited causes of calcium urolithiasis, are both associated with nephrocalcinosis and urolithiasis in early childhood and renal failure that can occur at any age but is seen more often in adulthood. Bone disease is an inconsistent feature of each. Dent's disease is caused by mutations of the CLCN-5 gene with impaired kidney-specific CLC-5 chloride channel expression in the proximal tubule, thick ascending limb of Henle, and the collecting ducts. Resulting hypercalciuria and proximal tubule dysfunction, including phosphate wasting, are primarily responsible for the clinical manifestations. Low-molecular-weight proteinuria is characteristic. Definitive diagnosis is made by DNA mutation analysis. Primary hyperoxaluria, type I, is due to mutations of the AGXT gene leading to deficient hepatic alanine-glyoxylate aminotransferase activity. Marked overproduction of oxalate by hepatic cells results in the hyperoxaluria responsible for clinical features. Definitive diagnosis is by liver biopsy with measurement of enzyme activity, with DNA mutation analysis used increasingly as mutations and their frequency are defined. These disorders of calcium urolithiasis illustrate the value of molecular medicine for diagnosis and the promise it provides for innovative and more effective future treatments.
 ...
PMID:Stones, bones, and heredity. 1680 Nov 62

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.
 ...
PMID:Oxalobacter formigenes: a potential tool for the treatment of primary hyperoxaluria type 1. 1698 27

Idiopathic hypercalciuria (IH) is defined as hypercalciuria that persists after correction of dietary inbalances and has no detectable cause. The excretion of urinary N-acetyl-beta-D-glucosaminidase (U-NAG), a marker of proximal tubular damage, has been previously reported as either increased or normal in children with IH. We evaluated U-NAG in 20 children (13 boys and 7 girls, mean age 10.3 years +/- 5.7 SD) with IH (urinary calcium excretion above 0.1 mmol/kg/24 hours, with no detectable cause) and with otherwise normal renal function tests. Ultrasound examination revealed urolithiasis (n=4) and nephrocalcinosis (n=1). The U-NAG values were evaluated in the spot urine collected from the second morning void and calculated as the urinary NAG/creatinine ratio (U-NAG/Cr) and expressed in nkat/mmol. The 24-hour urinary calcium excretion (U-Ca/24h) was assessed in a urinary sample from 24-hour collected urine and calculated in mmol/kg. The obtained results of U-Ca/24h and U-NAG/Cr were expressed as Z-scores. When compared to the reference data, the U-Ca/24h and U-NAG/Cr were significantly higher (p = 0.0004 and p = 0.006, respectively). There was no correlation between the U-NAG/Cr and U-Ca/24h (r = 0.18, p = 0.20). The U-NAG/Cr values were significantly higher in the 5 patients with urolithiasis/nephrocalcinosis, whether compared to the rest of the group (p = 0.02), or to the reference data (p = 0.01). The U-NAG/Cr activity was higher in 15 children without urolithiasis/nephrocalcinosis when compared to reference data (p < 0.01). There was no difference in U-Ca/24h between the children with and without urolithiasis/nephrocalcinosis (p = 0.58). These findings suggest that tubular impairment, as reflected by U-NAG/Cr, might occur in children with IH, especially in patients with urolithiasis/nephrocalcinosis. There doesn't seem to be a direct relationship between the U-NAG/Cr activity and the degree of calcium leakage.
 ...
PMID:Renal tubular impairment in children with idiopathic hypercalciuria. 1695 19

Hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome is an autosomal dominant disorder characterized by hypoparathyroidism, sensorineural deafness and renal dysplasia. Herein, we report a case of HDR syndrome associated with nephrocalcinosis and distal renal tubular acidosis. A 34-year-old woman was admitted to investigate recurrent stone formation and bilateral nephrocalcinosis. As a 3-year-old child, she had been diagnosed with HDR syndrome without chromosome evaluation. She had spontaneous stone passages on several occasions. On laboratory examination, serum calcium and intact parathyroid hormone at lower levels. Urinary citrate excretion was extremely low at 51.6 mg/day. On an ammonium chloride loading test, complete distal renal tubular acidosis was proved. To prevent the nephrocalcinosis from deteriorating, she was given potassium-sodium citrate. Since administration, she has not experienced spontaneous stone passage or renal colic. Nephrocalcinosis and recurrent urolithiasis will strongly affect renal prognosis in this case and we consider that citrate medication is an effective therapy in avoiding progress of her nephrocalcinosis.
 ...
PMID:Case of hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome associated with nephrocalcinosis and distal renal tubular acidosis. 1751 29

Hyperoxaluria can lead to multiple pathologic conditions such as recurrent urolithiasis, oxalosis, nephrocalcinosis and even renal failure, but there is no known oxalate-degrading pathway in the human body, and current therapeutic options for patients with hyperoxaluria are limited. Oxalyl-CoA decarboxylase and formyl-CoA transferase are the key enzymes in the oxalate catabolism of Oxalobacter formigenes which dwell in the intestine of vertebrates and have an important symbiotic relationship with their hosts. The aim of this study was to insert the oxalate-degrading enzyme genes into human embryo kidney (HEK) 293 cells and to evaluate if the oxalate-degrading enzymes could be expressed in these cells and keep their enzyme activity. We present here the cloning of the two genes from O. formigenes and their subsequent expression in HEK293 cells. The results showed that the expression of oxalyl-CoA decarboxylase and formyl-CoA transferase was confirmed by RT-PCR and Western blotting, and the proteins were located in the cytoplasm of transfected cells. Furthermore, the transfected cells were capable to a certain degree of degrading oxalate. These findings suggest that the transfer of oxalate-degrading enzyme genes into human cells is possibly a potential candidate for the gene therapy of hyperoxaluria.
 ...
PMID:Stable expression of the oxc and frc genes from Oxalobacter formigenes in human embryo kidney 293 cells: implications for gene therapy of hyperoxaluria. 1778 82

Primary hyperparathyroidism in children is very rare. It is caused by overproduction of parathormone by a pathologically changed parathyroid gland. We carried out a retrospective study in 10 patients (age 10-17 years) who had surgical treatment between 1996 and 2007. The main signs of primary hyperparathyroidism were urolithiasis, nephrolithiasis, nephrocalcinosis and bone resorption, as well as non-specific signs such as fatigue, torpidness and muscle weakness. Patients were examined using sonography, MIBI-scintigraphy, CT and MRI. Calcium was measured before and after surgery; parathormone was monitored postoperatively. Surgery was curative in nine patients; reoperation was necessary in one patient because an ectopic parathyroid gland was not detected during the primary operation. Other major complications were not observed. Removal of pathologically changed parathyroid glands offers definitive and safe treatment of primary hyperparathyroidism in children. Special care should be taken if an ectopic parathyroid gland is suspected.
 ...
PMID:Surgical treatment of primary hyperparathyroidism in children: report of 10 cases. 1851 6

Two West Indian manatees (Trichechus manatus spp.) were reported with severe emaciation. One animal was a Florida manatee from the Everglades; the other was an Antillean manatee from Cuba. On necropsy, both animals had nephrolithiasis, pyelonephritis, and moderate to severe renomegaly. Histopathology revealed multifocal to diffuse pyelonephritis, interstitial nephritis, and nephrocalcinosis. The stones were analyzed and consisted primarily of calcium carbonate. Serum chemistry values for the Florida animal revealed no renal abnormalities. The mechanism of calculus formation remains unclear in manatees. In horses, another hindgut fermenter, the most common urolith is also calcium carbonate. Urinalyses performed on manatees are very similar to those of horses (i.e., alkaline urine, low specific gravity, and calcium carbonate crystals). Formation of uroliths in manatees may have a pathogenesis similar to equine urolithiasis.
 ...
PMID:Nephrolithiasis and pyelonephritis in two West Indian manatees (Trichechus manatus spp.). 1868 58

Urolithiasis and nephrocalcinosis are more frequent in children then currently anticipated, but still remain under- or misdiagnosed in a significant proportion of patients, since symptoms and signs may be subtle or misleading. All children with colicky abdominal pain or macroscopic hematuria should be examined thoroughly for urolithiasis. Also, other, more general, abdominal manifestations can be the first symptoms of renal stones. The patients and their family histories, as well as physical examination, are important initial steps for diagnostic evaluation. Thereafter, diagnostic imaging should be aimed at the location of calculi but also at identification of urinary tract anomalies or acute obstruction due to stone disease. This can often be accomplished by ultrasound examination alone, but sometimes radiological methods such as plain abdominal films or more sensitive non-enhanced computed tomography are necessary. Since metabolic causes are frequent in children, diagnostic evaluation should be meticulous so that metabolic disorders that cause recurrent urolithiasis or even renal failure, such as the primary hyperoxalurias and others, can be ruled out. The stone is not the disease itself; it is only one serious sign! Therefore, thorough and early diagnostic examination is mandatory for every infant and child with the first stone event, or with nephrocalcinosis.
 ...
PMID:Diagnostic examination of the child with urolithiasis or nephrocalcinosis. 1910 42


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>