Nephrolithiasis: Presence Of Renal Calculi
Nephrolithiasis or stones in the urinary tract approximately cost $2.1 billion in a year in the United States, affecting about 0.2% of the US population annually. Between 5% and 15% of Americans will suffer from renal calculi sometime during their lifetime. Men suffer with kidney stones more often than women do and White men have three times more attacks than black men, except for ammonium magnesium phosphate (struvite) stones, which occur more often in black men.
About 75% of all stones are calcium-based, consisting of calcium oxalate, calcium phosphate, or a mixture of oxalate and phosphate. Another 10% of renal stones are uric acid-based, 1% are cystine-based, and the remainder are primarily struvite. In susceptible patients, stone formation begins when urine is supersaturated with calcium, cystine, uric acid, struvite, or oxalate.
Two fundamental processes are involved in the pathogenesis of Nephrolithiasis, namely, supersaturation and nucleation. Supersaturation occurs when the substances that make up the stone are found in large volumes in the urine, when urine volume decreases, and when the chemicals in urine that inhibit stone formation decrease. Inhibitors of crystallization include citrate, magnesium, pyrophosphate, nephrocalcin, uropontin, and Tamm-Horsfall mucoprotein. The latter three being proteins synthesized in the kidney. In addition, a urinary pH of less than 5.5 favors uric acid crystallization, while a urinary pH greater than 6.5 favors an increase in divalent and trivalent phosphate ions.
With the nucleation process, sodium hydrogen urate, uric acid, and hydroxyapatite crystals form a nucleus. Calcium and oxalate ions then adhere to the nucleus to form a mixed stone. This is known as heterogeneous nucleation.
Anyone who has experienced the agony of a kidney stone knows the importance of avoiding future attacks. Still, recurrence rates continue to be high, with one of every two patients having another stone within 5 years. Kidney stones must be watched out for and steps must be taken to prevent formation of new stones.
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This blog is sponsored by http://www.kidneystoneblog.com I am very curious about kidney stone removal that’s why I have made this blog. I am too much curious about latest development in this field.
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