Calculi in the urinary tract

Calculi in the urinary tract Acute gastroenteritis Acute pancreatitis Lumbar pain Acute pyelonephritis Acute glomerulonephritis Acute renal failure Edema Acute appendicitis Peritonitis Trauma... 

DC shock pulses have also been used for destroying calculi in the urinary tract,... 

Approximately 10% of the human population (with regional differences indicating both genetic and environmental factors [33]) is affected by the formation of stones or calculi in the urinary tract. Urolithiasis is not only a painful condition, but also causes annual costs to the health system in the order of billions of dollars in the USA alone [34, 35]. Based on their composition, structure and location in the urinary tract, renal stones have been classified into 11 groups and their formation mechanisms have been discussed together with alterations in urinary parameters and metabolic risk factors for renal lithiasis [35]. Approximately 70% of these stones contain calcium oxalate monohydrate (COM) and dihydrate as major components, while other calculi are composed of ammonium magnesium phosphate (struvite), calcium phosphates (hydroxyapatite and brushite), uric acid and urates, cystine and xanthine. An accurate knowledge of the solubilities of these substances is necessary to understand the cause of renal or bladder calculi formation and find ways towards its prevention and treatment [36]. 

An excessive uptake in soluble silica by cattle, unaccompanied by enough water to remove if from e system, can lead to stones or calculi in the urinary tract (210, 211), esp ially if concentration in the urine exceeds 70-80 ppm (212). Similarly, dogs fed on a diet high in silicate bulking constituents developed siliceous stones in the kidneys, bladders, and urethras (213). 

Litholytic agents in current use are classified as direct or indirect. Indirect type drugs decrease the C.P. of urine, thus inhibiting calculus formation. An example is citrate which helps prevent insoluble salts from crystallizing in the urinary tract. Potassium citrate is administered in pill form as a preventive drug. Direct type drugs dissolve renal calculi which have already formed. 

Calcium and oxalate arc closely associated with the fomiation of stones in the urinary tract. Kidney stones (renal calculi) and bladder stones are mineral deposits containing protein. They can have a diameter of a centimeter or greater. Most kidney stones (75%) are composed mainly of calcium oxalate or calcium oxalate with hydroxyapatite. Uric acid stones account for about 10% of stones xanthine stones are rare. Calcium containing kidney stones occur in fetem nations and affect about one person in 1000. The disease may occur in children, but typically occurs after rhe age of 30 and in men, Calcium biadder stones occur malniy in the children of underdeveloped countries, such as Thailand, and occur rarely in West em nations. Some kidney stones do not result in symptoms. Others may cause blood loss in the urine. Stones that obstruct the flow of urine from the kidney into the ureter result in violent pain, nausea, and vomiting. 

Renal stones (calculi) produce severe pain and discomfort, and are common causes of obstruction in the urinary tract (Fig. 2). Chemical analysis of renal stones is important in the investigation of why they have formed. Types of stone include ... 

CT imaging is progressively gaining an important role in the management of patients with suspected lithiasis of the urinary tract. An unenhanced scan of the entire abdomen performed in a single breath-hold, at high resolution, allows the depiction of calcifications in the urinary tract (Tublin et al. 2002). In difficult cases where the position of calcification cannot be precisely defined, the use of intravenous contrast helps in delineating the entire urinary map (Fig. 23.5) and also allows calculi located in the renal... 

This is a stone which may be formed in secreting organs or their ducts. They have been found in the salivary gland, pancreas and prostate but are most frequently encountered in the urinary tract and gall bladder. Urinary calculi usually consist of calcium, magnesium, oxalate, carbonate or phosphate but occasionally uric acid, cystine and xanthine stones occur as a result of a metabolic disease. Cholesterol and bilirubin are found in biliary stones. 

The formation of calculi (stones) of any kind (as in the urinary tract and gallbladder). 

Based on the United States Renal Data System, which reported their retrospective records of 42,096 renal transplant recipients between 1994 and 1998, the incidence of urolithiasis was 0.11% for males and 0.15% for females (Abbott et al. 2003). At the time of calculus discovery, 67% had kidney stones and 33% ureteral stones. Uric acid stones are much less common than calcium calculi. The stones can be transplanted from cadaveric or living donors or develop de novo, favored either by metabolic disorders (tertiary hyperparathyroidism, hypercalciuria, hypocitraturia) or infection (Proteus tnirabilis), or the presence of a foreign body in the urinary tract (double-J stent) (Crook and Keoghane 2005). 

Urinary calculi are frequent concomitants of vitamin A deficiency. The epithelium of the urinary tract shares in the general pathological changes of all epithelial structures. Epithelial debris thus may provide the nidus around which a calculus is formed. Abnormalities of reproduction include impairment of spermatogenesis, degeneration of testes, abortion, resorption of fetuses, and production of malformed offspring. 

In humans, urinary tract calculi are generally not present for long periods of time, in contrast to rodents (DeSesso 1995). This is because of the normal anatomy... 

Ilie clinical aiqylications of this amuoach are best represented in a study by Sampson ef cd. (1985) of measurement of the urinary disulfides cystine and cystdnyl-penicillamine in cystinuria patients. In order to diagnose this disease and monitor patient treatnient, it is necessary to monitor the relatively insoluble disulfides responsible for formation of these urinary tract calculi. Urine samples were simply deproteinized with sulfosalicyclic acid and diluted before injection. For patients treated with penicillamine to increase disulfide solubility in the renal tract, the cysteine-penicillamine... 

Another, quite different, example of the value of ECD in helping to solve a difficult methodological problem is the measurement of urinary oxalate. Excessive excretion of oxalate in the urine is likely to lead to the formation of calculi in the kidney or the urinary tract. By maintaining urinary oxalate excretion within normal limits, the likelihood of oxalate stone formation is considerably reduced and thus this test is frequently requested by urologists. 

Wolfe and Salter showed that in the vitamin A-deficient mouse there were extensive changes in the bladder and pelvis of the kidney. They found that the normal epithelium was replaced by one which had become keratinized and that the bladder had become filled with desquamating cells (see Figs. 12 and 13). There was also desquamation of the epithelium in the pelvis, and the kidney itself showed evidence of leucocytic infiltration. There were, however, no morphological changes in the cells of the kidney tubules. It has been pointed out by Bicknell and Prescott that the cells shed by the epithelium of the urinary tract form a nidus around which urinary salts may be deposited, thus building up calculi. A number of authors, e.g., Eddy and Dalldorf, have recorded an increased number of urinary calculi in vitamin A-deficient animals. 

Percutaneous treatment of diseases affecting the urinary tract most often begins with accessing a collecting system and placing a nephrostomy tube. Thus, nephrostomy insertion is the basic technique upon which percutaneous surgical procedures are built. This chapter discusses nephrostomy tube insertion, ureteral stent insertion, ureteral stricture dilatation, nephrostomy tract dilatation, percutaneous removal of calculi, endopyelotomy techniques used in the treatment of UPJ strictures and percutaneous renal angioplasty for treatment of renovascular hypertension. 

Urinary lithiasis is a disease in which calculi form in the kidney and urinary tract. Roughly 5 % of the human population suffers to some degree from urinary lithiasis. A number of severely afflicted patients (e.g. ca. 60,000 in West Germany and more than 100,000 in the U.S.) are hospitalized yearly for major surgical treatment. Obviously, nephrolithiasis is not only a common ailment but also an issue of great social and economic consequence. 

In the various studies and consumer references, many dosages and dosing regimens have been reported for the use of cranberry in prevention of renal calculi, prevention of urinary odor, and prevention and treatment of urinary tract infections. 

The method used for the collection of luine to detect urinary solids is particularly sensitive to a variety of artifacts and variations in treatment (Cohen et al. 2007). Most of all, it is essential that the animals not be fasted or go without water during the period of collection of urine. Since the excretion of the substances that are included in formation of the urinary solids is dependent on their consmnption, fasting the animals changes the urine composition considerably and can lead to a condition in which the solids are no longer formed. Fiulhermore, urinary solids can be rapidly excreted in the mine and are not retained so if they are not being constantly formed anew, they will not be detected. This includes urinary tract calculi. Some calculi will be small enough that they will be excreted in the urine, or dissolve with the lowering of the concentration of the solute itself. Furthermore, many of these calculi are actually quite soluble in urine, such as uracil, and rapidly solubilize in the urine. 

Numerous studies have examined the relationship of urinary tract sofids to toxicity and to bladder cancer in humans (Burin et al. 1995 Cohen et al. 2000 La Vecchia et al. 1991 RBCWG 1995). The evidence suggests that lumary amorphous precipitate and urinary crystals of any kind are not associated with cytotoxicity or deleterious effects in humans. Crystalliuia in hmnans is not associated with any toxicological response (McPherson et al. 2006 Pearle and Lotan 2007). In some instances it can be an indication of the propensity of the individual to form calculi from these substances, such as calcium oxalate, or occasionally it can be an indication of systemic metabolic disturbances, such as gout, oxalosis, or hypercalcemia. 

Moreover, the types of tumors associated wifii bacterial cystitis and calculi, as well as with other infectious inflammatory processes in the bladdm, such as schistosomiasis, frequently are squamous cell carcinomas, in contrast to the usual transitional (urothelial) ceU carcinomas that occur in the bladdm (Oyasu 1995). In rodents, the tumors associated with urinary tract solids are for the most part transitional (mothelial) cell tumors rather than squamous ceU proliferations. 

Thus, in assessing potential bladder cancer risk for humans based on studies in rodents, consideration of a threshold dose response is the foremost consideration. The differences in composition of the urine, anatomic differences, and especially exposure differences between rodents and humans must be taken into account. Furthermore, the evidence for a relationship for urinary tract calculi to an increased risk of bladder cancer is relatively weak and is complicated by the usual association of bacterial cystitis with the presence of long-standing calculi. Urinary precipitate and crystals are not relevant to human carcinogenesis, in contrast to rodents. 

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