MLT 130 Final Endocrinology, Body Fluids, Toxicology 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; direct
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 urobilinogen and 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?
0.0-0.2 mg%
Indirect bilirubin is converted to direct bilirubin by conjugation with _______ ____ by the ____ ____.
glucuronic acid
liver cells
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
In the Jendrassik-Grof method for bilirubin determination, bilirubin reacts with what reagent to form the purple compound azobilirubin?
In this method, what reagent is used to dissolve free bilirubin?
diazotized sulfanilic acid
caffeine
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 due to blockage
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
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?
NOT water soluble
What color is urine which contains large amounts of porphyrins?
port wine; magenta
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; reduced activity of glucuronyltransferase
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
Why is bilirubin unstable once the specimen has been centrifuged?
light sensitivity
What observation is used to determine urinary porphyrins?
Red fluorescence in UV light
What is the basic unit of the structure of porphyrins?
pyrrole rings
What specific pigment is possible for the color of normal adult feces?
urobilin
What is 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?
What value for sweat chloride is indicative of cystic fibrosis?
pancreas
60-200 mg/dL
In what test is 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 gauze/filter paper 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?
kidneys
filtered and interpreted
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 (aspirin)
What poisons are tested for by the Reinsch test?
Arsenic and mercury
Heavy Metals
NOT Pb
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 and nails
What level of carboxyhemoglobin can be found in cigarette smokers?
5-15%
What is the purpose of the Tindar reaction?
detect 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 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 the blood in cases of carbon monoxide poisoning?
bright cherry red
What enzyme is decreased due to insecticide poisoning?
pseudocholinesterase
Name the point-of-care test 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
What does AFP stand for?
alpha fetoprotein
What does CEA stand for?
carcinoembryonic antigen
Name the metabolites of epinephrine, norepinephrine and dopamine.
Metanephrine(E)
Normetanephrine(N)
Vanillylmandelic acid (VMA)-(E&N)
Homovanillic acid(HVA)- dopamine
In the determination of 17-ketosteroids, what is Zimmerman reagent composed of?
meta-dinitrobenzene
The renal excretion of Na+, which in turn affects serum levels, is controlled by hormones produced where? What is the major hormone responsible for water and electrolyte balance?
adrenal cortex
aldosterone
Explain lab findings, in regards to thyroid hormones and TSH, in hyperthyroidism and hypothyroidism.
hyper-increase T3/T4, decrease TSH
hypo-decreased T3/T4, increased TSH
1-nitroso-2-naphthol is used in the analysis of which amine metabolite? What amine is this a metabolite of?
5-HIAA
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. The resulting compound is converted to vanillin which is reacted with periodate. Colored product of the reaction is measured spectrophotometrically. With VMA, sodium is used but measurement performed the same as other catecholamines.
Give a brief description of Grave’s disease.
autoimmune disorder 6x more frequent in women. typical symptoms of hyperthyroidism. Abs stimulate the thyroid by binding to TSH receptors causing diffuse hyperplasia. Labs indicate;
increased T3, T4, FT4I, T3U
decreased or normal TSH
may have exopthalmia and goiter
What is the first and best indicator of hyper- or hypothyroidism?
TSH
What are the catacholamines?
epinephrine
norepinephrine
dopamine
Which hormones does the thyroid gland produce?
calcitonin
T3-triiodothyronine
T4-thyroxine
What is another name for epinephrine?
adrenaline
To which amino acid does 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.
Underfunction of adrenal cortex
decrease 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?
hyperadrenalcorticalism
HCG is produced by the ? and begins to rise within ? after conception.
placenta
1-2 days
Briefly explain the function of vasopressin.
stimulates reabsorption of water by the kidney tubules
Where is the hormone epinephrine produced?
adrenal medulla
Argentaffinomas 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 from the ?
1/3 comes 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 pineapple plums walnuts tomatoes kiwi 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-B-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.
increase cortisol levels cause the hypthalamus and pituitary to decrease production of CRH and ACTH
decrease ACTH causes adrenal glands to decrease cortisol production
