MLT 130 Final Endocrinology, Body Fluids, Toxicology Flashcards by Alex Olsen

What fraction(s) of bilirubin is/are increased in a hemolytic disorder?

unconjugated

total

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Which fraction might be expected to be increased in a hepatic disorder?

conjugated; direct

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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

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Where and from what substance is urobilinogen formed?

bilirubin

Bacteria from intestines

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Another name for prehepatic jaundice is _______.

hemolytic

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Another name for posthepatic jaundice is _______.

obstructive

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Another name for FREE (indirect) bilirubin is _______.

unconjugated

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Another name for direct bilirubin is _______.

conjugated

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What is the normal range for direct bilirubin?

0.0-0.2 mg%

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Indirect bilirubin is converted to direct bilirubin by conjugation with _______ ____ by the ____ ____.

glucuronic acid

liver cells

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In what condition is conjugated bilirubin increased?

biliary obstruction

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In the Evelyn-Malloy method for bilirubin, quantitation of the bilirubin is made by measuring _______.

azobilirubin

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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

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What reagents are used in the Watson-Schwartz test?

Ehrlich's reagent
Chloroform
N-Butanol
Sodium acetate
(NOT Diethyl ether)

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How are porphobilinogen and urobilinogen distinguished from each other since both form a colored compound with p-aminobenzaldehyde?

Porphobilinogen is extracted by chloroform

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In the synthesis of heme, what is the direct precursor of porphobilinogen?

Delta-aminolevulinic acid (Delta ALA)

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Why is the stool clay-colored in obstructive jaundice?

urobilinogen is absent due to blockage

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To what compound is free bilirubin in the plasma attached?

albumin

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What compound is the precursor of uroporphyrin, coproporphyrin, and protoporphyrin?

porphobilinogen

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If you know the total bilirubin and the conjugated bilirubin values, how can you determine the value for the unconjugated bilirubin?

total - conjugated

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Name the three enzymes involved in heme synthesis that are inhibited by lead.

Delta ALA synthase
Porphobilinogen deaminase
Ferrochelatase

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What is the composition of Erhlich’s reagent?

*Diazotized sulfanilic acid

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Why is unconjugated bilirubin NOT found in the urine?

NOT water soluble

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What color is urine which contains large amounts of porphyrins?

port wine; magenta

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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?

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