urine screening (metabolic disorders) Flashcards
1
Q
- Tryptophan produces serotonin
- Serotonin from tryptophane is produced by the intestinal argentaffin cells and is carried in the body to the muscles by platelets
- Excess excreted in the urine as (?)
- Argentaffin cell tumors = ↑ ↑ (?) in urine from excess serotonin produced
- Nitrous acid and 1-nitroso-2-naphthol produce purple to black color
- Normal: 2-8 mg/day, >25 mg/day in disease
- Can perform test on random specimens
- No bananas, pineapples, tomatoes, phenothiazines, and acetanilids for 72 hours
- 24-hour urines must be preserved with HCl or boric acid
A
5-HIAA
2
Q
homogentistic acid test
- Addition of silver nitrate and ammonium hydroxide to urine
- black urine
A
Ammoniacal Silver Nitrate Test
3
Q
- skeletal structure is abnormal and there is severe mental retardation
- Bone marrow transplants and gene replacement therapy
- acid-albumin (turbidity after 30 mins)
- cetyltrimethylammonium bromide (CTAB) turbidity tests (turbidity after 5 mins)
- Metachromatic staining (blue spot)
A
hunter syndrome
4
Q
- p-hydroxyphenylpyruvic acid dioxygenase
- result in mental retardation if dietary restrictions of phenylalanine and tyrosine are not implemented
A
type 3 tyrosinemia
5
Q
one of Garrod’s original six IEMs
A
pentosuria
6
Q
- port wine color after air exposure, also seen on
diapers
§Ehrlich reaction: only for ALA and porphobilinogen - Convert ALA to porphobilinogen by adding acetyl acetone
- Fluorescence under ultraviolet light used for other porphyrins; extract into glacial acetic acid and ethyl acetate; does not distinguish
- Violet, pink, red, based on concentration
A
porphyrin disorders
7
Q
- Enzyme deficiency is homogentisic acid oxidase
- Black alkaline urine, possible black-stained diapers
- Manifests later in life with brown pigment deposits in tissues
- blue with ferric chloride
- yellow precipitate with clinitest
- black with silver nitrate and ammonium hydroxide
A
alkaptonuria
8
Q
- tyrosine aminotransferase
- Persons develop corneal erosion and lesions on the palms, fingers, and soles of the feet believed to be caused by crystallization of tyrosine in the cells
A
type 2 tyrosinemia
9
Q
- Current state-mandated screening for as many as 29 inborn errors of metabolism
- Urine tests are primarily for follow-up
- Disorders can cause abnormal urinalysis results
- Heel stick blood tests are used for testing
- Performed before infant leaves hospital
- Metabolites appear first in the blood
- Analyze by tandem mass spectrophotometry, MS/MS
- Gene testing is being worked on
A
newborn screening
10
Q
melanuria
- oxidation of chromogen
- gray or black ppt
A
ferric chloride tube test
11
Q
- Fumarylacetoacetate hydrolase (FAH)
- Produces a generalized renal tubular disorder and progressive liver failure in infants soon after birth
A
type 1 tyrosenemia
12
Q
- Breakdown in a normal metabolic pathway causing accumulation of previous metabolite
- Overrides Tm or is not normally reabsorbed
- Inherited lack of specific enzyme for protein,fat, or carbohydrate metabolism–Inborn Error of Metabolism
A
overflow
13
Q
- Differentiation of urobilinogen, porphobilinogen and other Ehrlich-Reactive Compounds.
- Extraction with CHLOROFORM and BUTANOL
A
watson-schwartz test
14
Q
- 1 in 10,000 births
- Autosomal-recessive; heterozygotes normal
- Damage to child’s mental capacity
- Alternate pathways as child matures
- Avoid ↑ phenylalanine foods (aspartame)
- Urine and 5% ferric chloride produces a permanent green-blue color
A
phenylketonuria
15
Q
- immediate precursor to methylmalonic acid
- errors in the metabolic pathway converting isoleucine, valine, threonine, and methionine to succinyl coenzyme A
A
propionic acidemia
16
Q
- crystalline deposits of cystine in many areas of the body
- defect in the lysosomal membranes
- Positive test results for reducing substances
A
cystinosis
17
Q
amino acid disorders (aminoacidurias)
A
- Phenylketonuria,
- tyrosyluria,
- alkaptonuria
18
Q
- Inborn error of metabolism, autosomal-recessive
- 1-week failure to thrive is noticed
- Urine: strong odor of maple syrup, and thick, dark appearance
- Dietary regulation
- Screening test 2,4-dinitrophenylhydrazine produces yellow precipitate turbidity
- Positive urine ketones
A
MSUD
19
Q
melanuria
- Screening test
- red color
A
sodium nitroprusside test
20
Q
- increase in homocystine throughout the body
- Defect in methionine metabolism
- (+) cyanide-nitroprusside test plus (+) silver nitroprusside test
A
homocystinuria
21
Q
- parenteral feeding
- ingestion of large amounts of fruit
A
fructosuria
22
Q
Cyanide-Nitroprusside Test
False-positives:
(?), (?)
A
- ketonuria
- homocystinuria
23
Q
melanuria
- Interference à add glacial acetic acid (reverts color greenish-black)
- Acetone
- Creatinine
- purple
- amber
A
sodium nitroprusside test
24
Q
DNPH test interference
- Large doses of (?)
- a positive reagent strip test result for (?) produce a positive DNPH result
A
- ampicillin
- ketones
25
Q
- deficiency in any of three enzymes, galactose-1-phosphate uridyl transferase (GALT), galactokinase and UDP-galactose-4-epimerase
- inability to properly metabolize galactose to glucose
A
galactosuria
26
Q
Media containing beta-2-thienylalaline, an inhibitor of Bacillus subtilis, is streaked with the bacteria; blood impregnated discs placed on the agar; phenylalanine counteracts the inhibitor, and bacteria grow around the disc
A
guthrie blood test
27
Q
- Failure to inherit the gene to produce the enzyme hypoxanthine guanine phosphoribosyl-transferase
- severe motor defects
- mental retardation
- tendency toward self destruction
- Gout
- renal calculi
- Presence of uric acid crystals resembling orange sand in diapers
- Microscopic–presence of increased uric acid crystals in pediatric urine specimens
A
lesch-nyhan disease
28
Q
- Mental retardation
- Bone marrow transplants and gene replacement therapy
- acid-albumin (turbidity after 30 mins)
- cetyltrimethylammonium bromide (CTAB) turbidity tests (turbidity after 5 mins)
- Metachromatic staining (blue spot)
A
sanfillippo syndrome
29
Q
- skeletal structure is abnormal and there is severe mental retardation
- mucopolysaccharides accumulate in the cornea of the eye.
- Bone marrow transplants and gene replacement therapy
- acid-albumin (turbidity after 30 mins)
- cetyltrimethylammonium bromide (CTAB) turbidity tests (turbidity after 5 mins)
- Metachromatic staining (blue spot)
A
hurler syndrome
30
Q
accumulation of organic acids further down in pathway
A
organic acedemias
31
Q
- errors in the metabolic pathway converting isoleucine, valine, threonine, and methionine to succinyl coenzyme A
- p-nitroaniline urine Test (emerald green)
A
methylmalonic acidemia
32
Q
- have noticeable odor of sulfur
- Inherited disorder affecting renal reabsorption
- Two modes of inheritance:
1. only cystine and lysine are not reabsorbed
2. cystine, lysine, arginine, and ornithine are not reabsorbed - Increased calculi formation early in life for both modes
- More common in 4 amino acids inheritance
- elevated amino acid cystine in urine (+) cystine crystals in urine
- inability of the renal tubules to reabsorb cystine filtered by the glomerulus
- Cyanide-nitroprusside Test (red-purple color)
A
cystinuria
33
Q
early degradation products accumulate
A
maple syrup urinde disease (MSUD)
34
Q
- Sweaty feet odor of urine
- Accumulation of isovalerylglycine
- isovaleryl coenzyme A deficiency in the leucine pathway
- MS/MS
A
isovaleric acidemia
35
Q
seen during pregnancy and lactation
A
lactosuria
36
Q
homogentistic acid test
- Screening test for metabolic disorder
- transient deep blue color in test tube
A
FeCl3 test
37
Q
homogentistic acid test
- test for reducing substance
- yellow precipitate
A
clinitest
38
Q
- Metabolic defects
- Underdevelopment of liver function
- Acquired severe liver disease
- Ferric chloride produces a transient green color—do not confuse with phenylalanine
- Nitroso-naphthol produces an orange-red color
A
tyrosyluria/tyrosinemia
39
Q
- Second pathway for tyrosine
- Pigment for dark hair, skin
- Defect causes albinism
- Increased production = malignant melanoma
- Dark urine from oxidation of melanogen
- Black precipitate with ferric chloride
- Red color with sodium nitroprusside
A
melanuria
40
Q
- Tryptophan enters intestine; is reabsorbed or is converted to indole by bacteria and leaves in the feces
- Intestinal disorders and Hartnup disease cause increased tryptophane conversion to indole
- Hartnup disease: blue diaper syndrome
- Inherited disorder affects intestinal reabsorption of indole and renal tubular reabsorption = Fanconi syndrome
- Requires dietary supplements
- Urine: blue or violet color with ferric chloride that can be extracted into chloroform
- Increased indole reabsorbed, excreted by kidney on its way to the liver
- Exposure of urine to air = indigo blue
A
indicanuria
41
Q
homogentistic acid test
- Screening test
- add alkali to freshly voided urine
- observe for darkening of the color (ascorbic acid interferes the test)
A
Urinary Homogentisic Acid Test
