Assessing kidneys

Assess kidney function by evaluating a patient s signs and symptoms, laboratory test results, and urinary indices. Calculate a patient s creatinine clearance to evaluate the severity of kidney disease. 

Most of the clinical laboratory information used to assess kidney function is derived from or related to measurement of the clearance of some substance by the kidneys. The renal clearance of a substance is defined as the volume of plasma from which the substance is completely cleared by the kidneys per unit of time. Provided a substance S is in stable concentration in the plasma is physiologically inert freely filtered at the glomerulus and neither secreted, reabsorbed, synthesized, nor metabolized by the kidney, then the amount of that substance filtered at the glomerulus is equal to the amount excreted in the urine (i.e., the amount of S entering the kidney must exactly equal the amount leaving it). The amount of S filtered at the glomerulus = GFR multiplied by plasma S concentration GFR X PS. The amount of S excreted equals the urine S concentration (US) multiplied by the urinary flow rate (V, volume excreted per unit time). 

The measurement of the GFR is of current interest in view of the fact that recent studies have questioned the accuracy of creatinine clearance and serum creatinine level for assessing kidney function and the rate of progression of renal disease (58). To recapitulate the value of the GFR as an index of the severity of renal disease, it should be pointed out that the GFR provides, in a sense, a direct measure of renal function and is reduced relatively early in the course of renal disease. 

Write nuclear equations for (a) alpha emission hy polonium-210, used in radiation therapy, (b) beta emission by gold-198, used to assess kidney activity, (c) positron emission by nitrogen-13, used in making brain, heart, and liver images, and (d) electron capture by gallium-67, used to do whole body scans for tumors. 

Gold-198, which is used to assess kidney function, has a half-life of 2.70 days. How long before a sample decreases to 146 of what was originally there Phosphorus-32, which is used for leukemia therapy, has a half-life of 14.3 days. What fraction of a sample is left in 42.9 days ... 

The concentration of urea in blood (blood urea nitrogen, BUN) is an important parameter in clinical chemistry for assessing kidney failure. Since urease enzyme sensors rely mainly on indication of the pH change during urea hydrolysis, problems in their application to body fluids are connected with the susceptibility of the sensors to disturbances by sample pH and buffer capacity. 

GFR and, consequently, of kidney function. Both are used to assess kidney function. 

A significantly better separation between the two disaccharides is obtained with a more complex NaOH gradient. Instead of zinc acetate, small amounts of sodium acetate are added to the mobile phase in order to elute more strongly retained saccharides within an acceptable time frame. Figure 3.236 shows a respective chromatogram with carbohydrates that are relevant for the analysis of urine to assess kidney functionality. In addition to lactose and lactulose, these carbohydrates include weso-erythritol, mannitol, sucrose, and turanose. Under these chromatographic conditions, resolution between lactose and lactulose is so large that even an excess of lactose does not prohibit clear quantitation of lactulose. 

Which Is the Most Accurate and Reliable Index to Assess Kidney Function for Drug Dosing, Thus Improving Drug Safety ... 

Subchronic Studies. Although short-term repeated exposure studies provide valuable information about toxicity over this time span, they may not be relevant for assessment of ha2ard over a longer time period. For example, the minimum and no-effects levels determined by short-term exposure may be significantly lower if exposure to the test material is extended over several months. Also, certain toxic effects may have a latency which does not allow their expression or detection over a short-term repeated-exposure period for example, kidney dysfunction or disturbances of the blood-forming tissues may not become apparent until subchronic exposure studies are undertaken. 

Some patients with reduced or absent parathyroid function, e.g., primary hypoparathyroidism, harbor anti-CaR antibodies (Fig. 2) [4]. In two patients, the antibodies were shown to activate the CaR as assessed by stimulation of MAPK and PLC. Tims, analogous to activating mutations of the CaR, anti-CaR antibodies can increase the sensitivity of the receptor to CaQ+, thereby resetting parathyroid and kidney to maintain hypocalcemia. 

Gower, J., Healing, G. and Green, C.J. (1989c). Measurement by HPLC of desferrioxamine-avaUable iron in rabbit kidneys to assess the effect of ischaemia on the distribution of iron within the total pool. Free Rad. Res. Commun. 5, 291-299. 

Friedlander, M.M., Kaufman, B., Rubinger, D., Moreb, J., Popovtzer, M.M. and Goredetsky, R. (1988). Noninvasivc assessment of skin iron content in haemodialysis patients. An index of parenchymal tissue iron content Am. J. Kidney Dis. XII, 18-25. 

Typical early in vitro permeability assessments measure the rate of flux of a compound from one side of a barrier to another [54, 55]. The barrier has historically been derived from a cell line, most commonly Caco-2 or Madin-Darby canine kidney (MDCK) cells. In the last several years, there has been substantial work and significant progress in the development of parallel artificial membrane permeability... 

Chymostatin-sensitive Il-generating enzyme Carvedilol Post-Infarct Survival Control in Left Ventricular Dysfunction Trial Collaborative Study Captopril Trial ( The Effect of Angiotensin-Converting Enzyme Inhibition on Diabetic Nephropathy ) calcium channel blocking agents Candesartan in Heart Failure Assessment of Reduction in Morbidity and Mortality Trial congestive heart failure, but the latest recommendations use HF for heart failure chronic kidney disease cardiac output... 

Assess a patient s kidney function based on clinical presentation, laboratory results, and urinary indices. 

Several equations have been developed to assess unstable kidney function. The Jelliffe equation (Table 22-1) estimates creatinine clearance by considering the change in serum creatinine over a specified time period.11 While it is more mathematically difficult to calculate, it better estimates creatinine clearance in patients with rapidly changing kidney function compared to an equation that only includes a single creatinine concentration. 

Renal ultrasound (uses sound waves to assess size, position, and abnormalities of the kidney dilatation of the urinary tract can be seen with postrenal ARF)... 

Renal angiography (administration of intravenous contrast dye to assess the vasculature of the kidney)... 

Retrograde pyelography (injection of contrast dye into the ureters to assess the kidney and collection system)... 

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