Test 5 Flashcards
What fraction(s) of bilirubin is/are increased in a hemolytic disorder?
Unconjugated/Total
Which fraction might be expected to be increased in a hepatic disorder?
Conjugated
In severe hemolytic jaundice, what would be expected results for bilirubin and urobilinogen in the urine, feces, and blood?
Urine - greatly increased urobilinogen
Feces - increased urobilin
Blood - increased unconjugated bilirubin
Where and from what substance is urobilinogen formed?
bilirubin
Bacteria from intestines
Another name for prehepatic jaundice is _______.
Hemolytic
Another name for posthepatic jaundice is _______.
Obstructive
Another name for FREE (indirect) bilirubin is _______.
Unconjugated
Another name for direct bilirubin is _______.
Conjugated
What is the normal range for direct bilirubin?
What is the normal range for Total Bilirubin
Direct: 0.0-0.2mg%
Total: 0.2-1.0
Indirect bilirubin is converted to direct bilirubin by conjugation with _______ ____ by the _______.
Glucuronic acid
Liver
In what condition is conjugated bilirubin increased?
Biliary obstruction
In the Evelyn-Malloy method for bilirubin, quantitation of the bilirubin is made by measuring _______.
Azobilirubin
What reagents are used in the Watson-Schwartz test?
Ehrlich's reagent Chloroform N-Butanol Sodium acetate (NOT Diethyl ether)
How are porphobilinogen and urobilinogen distinguished from each other since both form a colored compound with p-aminobenzaldehyde?
Porphobilinogen is extracted by chloroform
In the synthesis of heme, what is the direct precursor of porphobilinogen?
Delta-aminolevulinic acid (Delta ALA)
Why is the stool clay-colored in obstructive jaundice?
Urobilinogen is absent because of obstruction.
To what compound is free bilirubin in the plasma attached?
Albumin
What compound is the precursor of uroporphyrin, coproporphyrin, and protoporphyrin?
Porphobilinogen
If you know the total bilirubin and the conjugated bilirubin values, how can you determine the value for the unconjugated bilirubin?
TOTAL - CONJUGATED = UNCONJUGATED
Name the three enzymes involved in heme synthesis that are inhibited by lead.
Delta ALA synthase
Porphobilinogen deaminase
Ferrochelatase
What is the composition of Erhlich’s reagent?
Diazotized sulfanilic acid
Why is unconjugated bilirubin NOT found in the urine?
It is not water soluble
What color is urine which contains large amounts of porphyrins?
Port wine
Increased bile pigments in the body causes the condition of _______.
Jaundice
In bilirubin methods, total bilirubin develops a color only after the reagent _______ _______ is added.
Methyl alcohol
What is the biochemical defect associated with Gilbert’s disease?
Defective transport of bilirubin from plasma to liver cells due to reduced activity of the enzyme glucuronyl tranferase
What is the most common condition leading to porphyrinuria?
Lead poisoning
What normal substance results in the formation of bilirubin when it is broken down?
Hemoglobin
What substance is increased in the urine of patients with lead poisoning?
Delta ALA is present
Why is bilirubin unstable once the specimen has been centrifged?
Sensitivity to light
What observation is used to determine urinary porphyrins?
Red fluorescence in UV light
What is the basic unit of the structure of porphyrins?
Pyrrole ring
What specific pigment is possible for the color of normal adult feces?
Urobilin
What is the indicated by the presence of lactic acid in duodenal contents?
Acute or chronic gastritis
stomach carcinoma
A sweat chloride is done to check for disorders of what organ?
Pancreas
What value for sweat chloride is indicative of cystic fibrosis?
Greater than 60 to 200 mEq/L
In what test in an ion exchange resin used?
Diagnex Blue test
In what condition is the gastric acidity low or absent?
Gastric carcinoma
What is the normal pH of gastric juice after stimulation by a test meal?
1.5 - 4.0
Duodenal fluid testing is used to diagnose diseases of the _______.
Pancreas
What substance is used to induce sweating in sweat chloride analysis?
Pilocarpine
In the sweat test, what should be the NEXT step once the electrodes are removed?
Remove gaws from arm and weigh it.
What is measured by the Diagnex Blue test?
Tubeless test of free HCl in gastric secretions/juices
What organ, besides the intestinal tract, must be properly functioning to do the Diagnex Blue test?
Kidney
What is included in the determination of total gastric acidity?
Free HCl and combined gastric acidity
What is the composition of Topfer’s reagent?
Dimethylaminobenzene
Toxic effects from the ingestion of rat poison can occur due to the presence of _______.
Fluoride
Ferric ions are used in the detection of which common drug?
Salicylates (asprin)
What poisons are tested for by the Reinsch test?
Arsenic and mercury
Why should you avoid contact with mercury?
It can be inhaled or absorbed by the skin - is extremely toxic
What is the sample of choice for most cases of poisoning?
Urine
What specimens are preferred in cases of arsenic poisoning?
Hair
Nails
What level of carboxyhemoglobin can be found in cigarette smokers?
5-15%
What is the purpose of the Trindar reaction?
Detection of Salicylates
Acetaminophen (Tylenol) is particularly toxic to the _______.
Liver
What enzyme is used to determine ethanol levels?
Alcohol dehydrogenase
What is oncofetal antigen?
A protein shown to exist in both embryo fetal tissue and cancer cells.
Which tumor marker is used to detect prostatic cancer?
PSA
Which tumor marker is used to detect testicular cancer?
- Beta HCG
- AFP
What color is in the blood in cases of carbon monoxide poisoning?
Bright (cherry) red
What enzyme is decreased in insecticide poisoning?
Pseudocholinesterase
Name the POCT that is useful in the diagnosis of congestive heart failure?
BNP
Name one cardiac marker that is used in the triage cardiac panel the specimen for which can be collected in the ER by fingerstick.
Troponin I
What does AFP stand for?
Alpha-fetoprotein
What does CEA stand for?
Carcinoembryonic antigen
Name the metabolites of epinephrine, norepinephrine and dopamine
Metanephrine, normetanephrine, VMA and homovanillic acid (HVA)
in the determination of 17-ketosteroids, what is Zimmerman reagent composed of ?
Metadinitrobenzene
The renal excretion of sodium, which in turn affects serum levels, is controlled by hormones produced where?
Adrenal Cortex
What is the major hormone responsible for water and electrolyte balance?
Aldosterone
Explain laboratory findings, in regards to thyroid hormones and TSH, in hyperthyroidism and hypothyroidism
Hyper Increases, thyroid hormones and decreases TSH
Hypo Decreases, thyroid hormones and Increases TSH
1-Nitroso-2-naphthol is used in the analysis of which amine metabolite?
5-HIAA
Want amine is this a metabolite of?
serotonin
Where would you find a pheochromocytoma
Adrenal medulla
Urinary 17- ketosteroids may be elevated in diseases of which endocrine gland
Adrenal gland
Briefly explain the Pisano method. What is it used to measure
Acid Hydrolysis and absorption on an ion-exchange resin is followed by elution with ammonium hydroxide. Resulting compound is converted to a vinillin and reacted with periotdate. Colored product of the reaction is measure spectrophotometrically. With VMA, sodium metaperiodate is used but measurement performed the same as other catecholamines.
Give a brief description of Graves disease
It is an autoimmune disorder that occurs 6x more frequently in women than men, Frequency in general population about 0.04%. Ab’s stimulate thyroid by binding the TSH receptors causing diffuse hyperplasia of the thyroid Lab results indicate Increased T3,T4,FT4I,T3U and Decrease or normal TSH. May have exopthalimia and goiter.
What is the first and best indicator of hyper- or hypothyroidism
TSH
What are the catacholamines
Epinephrine, nonrepinephrine , and dopamine
Which hormones does the thyroid gland produce
Calcitonin,T3 and T4
What is another name for epinephrine
Adrenalin
To which amino acid dose the thyroid gland bind inorganic iodide from the plasma
tyrosine
What is the principle function of the pancreas
production of insulin and glucagon
Which organ is the major site of steroid metabolism
Liver
Briefly explain Addison’s disease
under function of adrenal cortex; decreased output of aldosterone, epinephrine, and cortisol as well as some supplementary sex hormones; it is a primary adrenal insufficiency
Cushing’s Syndrome is also known as
hyperadrenalcorticalsim
HCG is produced by the _____ and begins to rise within ______ after conception
- placenta
- 1-2 days
Briefly explain the function of vasopressin
stimulates re-absorption of water by the kidney tubules
Where is the hormone epinephrine produced
Adrenal medulla
Argentaffinomas was produced elevated levels of what
serotonin
Briefly explain the function of oxytocin
site of action =smooth muscle; main functions to stimulate contractions of uterus during delivery and contractions of breast tissue cells to cause milk ejection
What is the site of action for prolactin
Mammary glands
In men,2/3 of all 17-ketosteroids come fro the _____ and 1/3 from the _____
adrenals
testes
Name some conditions, other than pregnancy, where you may find increased HCG levels
Hydatidiform mole,choriocarcinoma, testicular tumors
What foods should be excluded from the diet for at least two days prior to collecting a urine specimen for 5-HIAA
Bananas, Avocados,pineapples, plums, walnuts, tomatoes, kiwi, and eggplant
How is most plasma thyroxine found
bound to globulin
what is the chief hormone excreted by the adrenal cortex
cortisol
the most potent and biologically active estrogen
is 17-Beta-estradiol
what is the action of progesterone
preparation of uterus for ovum implantation
what is the most potent of the biologically active androgens
testosterone
What is the parent substance in the biosynthesis of all adrenal cortical steroids
cholesterol
Of the thyroid iodide hormones, which is the most biologically active
T3
What Hormone regulates the rate of thyroid hormone synthesis and secretion and where is it produced
TSH/Anterior pituitary
Briefly explain the negative feedback mechanism in the relationship between cortisol and ACTH
Increased cortisol levels cause the hypothalamus and pituitary to decrease prodction of CRH and ACTH; Decrease ACTH causes adrenal glands to decrease cortisol production
