• Major end product of purine (adenine and guanine) catabolism

• Formed from xanthine by the action of xanthine oxidase

• Marker for detoxification

Used to diagnose hepatic failure/hepatic coma • Neurotoxic and associated with encephalopathy • Increased: cirrhosis, hepatitis, Reye’s syndrome, acetaminophen poisoning

• Final breakdown product of nucleic acids catabolism in humans

Major end product of protein and amino acid catabolism

End product of muscle metabolism derived from creatine

Produced by 3 amino acids: methionine, arginine, and glycine

• Not reused in the body’s metabolism (thus, solely a waste product)

• Index of overall renal function

Freely filtered by the glomerulus, not secreted by the renal tubules, but reabsorbed

ompletely reabsorbed and catabolized by the proximal convoluted tubules o (+) in urine = PCT damage • Serum level is an indirect estimate of GFR • Increased: acute and chronic renal failure, diabetic nephropathy

Its plasma concentration originates from the brain and is freely filtered at the glomerulus, reabsorbed completely, and catabolized by the proximal convoluted tubule • Increased: renal disease

– colorimetric, endpoint; non-specific; subject to positive bias due to ascorbic acid, glucose, glutathione, ketoacids, uric acid, cephalosporins

Creatinine + alkaline picrate = red-orange tautomer (aka Janovsky complex)

formed from creatine, a substance synthesized from methionine, arginine, glycine

excreted into plasma at a constant rate proportional to an individual’s muscle mass; not affected by hydration status

product of the catabolism of purines in nucleic acids or nucleoproteins

▪ relatively insoluble in plasma; can be deposited in the joints and tissues at concentrations >6.8 mg/dL

▪ produced from the catabolism of amino acids

toxic compound metabolized exclusively in the liver (via the Krebs-Henseleit or urea cycle)

removed from the circulation by glomerular filtration; concentration is inversely related to GFR

▪ NPN present in highest concentration in the blood; formed in the liver from CO2 and ammonia

▪ concentration is expressed in terms of nitrogen content (BUN): urea/2.14 Urea = BUN x 2.14

From deamination of amino acids

From bacterial metabolism in the lumen of the intestines

Clinical significance of Ammonia include: a. severe liver disease - hepatic coma (NH3 is neurotoxic) and Encephalopathy b. Reye syndrome - aspirin ingestion c. Neonate urea cycle defect d. Monitor hyperalimentation therapy e. Confirm the ability of kidney to produce ammonia f. Acetaminophen poisoning

Smoking

Prolonged specimen

Hemolyzed sample

Diphenhydramine

Lactobacillus acidophilus

Slows down deamination

Ammonia specimen centrifuge time

Ammonia temp

Removed during ammonia test processing

In ammonia testing, plasma is stable for how long in ice bath? (stable for several days when frozen)

NH3 in Microdiffusion chamber -> NH3 gas + solution with pH indicator -> measured using titration

Direct measurement

NH3 + bromophenol blue -> blue color

Most common technique

Tumor markers are NOT useful for diagnosis, but for tumor staging, monitoring therapeutic responses, predicting patient outcomes, and detecting cancer recurrence

Used for prostate cancer detection

Hepatocellular CA, testicular and ovarian teratocarcinomas, pancreatic carcinoma, gastric and colonic carcinomas

Digestive tract and colorectal carcinoma

Increased secretion is associated with trophoblastic tumors, choriocarcinoma, nonseminomatous testicular tumors, and ovarian tumors.

Monitoring and detecting breast cancer

Marker for ovarian and endometrial cancer

Pancreatic, colorectal, lung, and gastric carcinomas

Lung cancer marker

Breast cancer marker

older term

major end product of protein and amino acid

has nitrogen but doesn't have proteins

uses end point jaffe method before and after it is heat in acid solution

clinical significance include muscular dystrophy, poliomyelitis, hyperthyroidism, trauma, and remember!!! it is NOT ELEVATED IN RENAL DISEASE

Chronic renal disease

Burns

Dehydration

Poor nutrition

Celiac disease

Repeated dialysis

Acute tubular necrosis

most frequently used

alkaline picrate

alkaline picrate = SATURATED picric acid and 10% NaOH

creatinine + picric acid (alkaline solution) yields red-orange color

interferences AGAPA acetoacetate glucose acetone pyruvate ascorbate

More accurate and specific

Includes Fuller's earth = aluminum magnesium silicate, LLoyd's reagent = sodium aluminum silicate; TIME CONSUMING AND NOT READILY AUTOMATED

TIME CONSUMING AND NOT READILY AUTOMATED

Requires automated equipment for precision popular inexpensive rapid and easy to perform

Requires automated equipment for precision

Isotope dilution mass spectrometry is the reference method for NPNs

popular inexpensive rapid and easy to perform

specific than jaffe test

Fuller's earth

Lloyd's reagent

Increase in the conductivity due to NH4+ and CO32+ ions

NAD Decrease in the absorbance of 340 nm

Indophenol (Blue)

Dimercuric ammonium iodide (Yellow orange)

Yellow diazine derivative

• Not reabsorbed nor secreted by the tubules • Disadvantage: expensive, continuous IV infusion

Provides an estimate of the amount of plasma that must flow through the kidney glomeruli per minute

Demonstrate progression of renal disease or response to therapy

Does not give reliable estimates of the GFR since urea is freely filtered by the glomeruli and variably reabsorbed by the tubules

Excellent measure of renal function since creatinine is freely filtered by the glomeruli, minimally secreted in the tubules but not reabsorbed

Elevated concentrations of nitrogenous substances such as urea and creatinine in blood

Azotemia with renal damage

Azotemia with renal damage

Dehydration

Characterized by diminished glomerular filtration with normal renal function

Characterized by damage within the kidneys

Result of urinary tract obstruction

Marked elevation of plasma urea and other NPNs accompanied by acidemia and hyperkalemia

Characterized by anemia (normocytic, normochromic), uremic frost, generalized edema, foul breath, and sweat is urine-like

Kidneys fail to eliminate waste products of metabolism

Shock

Congestive heart failure

Diet

Stress

Fever

Corticosteroid

Acute chronic renal disease

Glomerulonephritis

Striking high urea level but slowly rising creatinine value

Effects: coma, neuropsychiatric changes, anemia, and electrolyte imbalance

Chronic glomerulonephritis = lengthy glomerular inflammation, gradual uremia, loss of function of nephrons

stone

Cancer or tumor of genitourinary tract

severe infection of the bladder

acidemia

hyperkalemia

anemia

burr cell or cremated cell

ammoniacal odor or breath

urine-like sweat

In chronic glomerulonephritis, glomerular inflammation is..

In chronic glomerulonephritis, uremia is..

In chronic glomerulonephritis, there is loss of function in..

Dehydration

Shock

Congestive heart failure

Diet

Stress

Fever

Corticosteroid

What is the GFR of a person who has Kidney damage with normal or ↑ GFR

What is the GFR of a person who has Moderate ↓ GFR

What is the GFR of a person who has stage 5 kidney failure?

Chronic nephritis, alcoholism, gout, leukemia, chemotherapy, Lesch-Nyhan syndrome

: Fanconi syndrome, severe liver disease, purine inhibitors, allopurinol

What is the GFR of a person who has Severe ↓ GFR

What is the GFR of a person who has Kidney damage with normal or ↓ GFR

Which chemical method for blood uric acid methodologies is associated with Sodium carbonate?

Tungsten (Blue)

Which chemical method for blood uric acid methodologies is associated with Sodium cyanide?

Decrease in the absorbance at 293 nm