- Liquid environmental (non-toxic, but toxic in vapor form) - Inorganic (non-toxic) - Organic (toxic)

Trace Elements Flashcards by Sarah Hoppa

List the essential trace elements

Iron
Zinc
Copper
Manganese
Chromium
Selenium

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List the non-essential trace elements

Arsenic
Mercury
Lead
Cadmium

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What tube is used for blood collection?

Royal blue top

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2 main methods of testing for trace elements

Atomic Absorption

Atomic Emission

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How does atomic absorption work?

Quantitates elements through absorption of optical radiation by free atoms in a gas phase.
Spectra of atoms is specific to absorbing elements

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How does atomic emission work?

Liquid sample with element is concerted into an aerosol and delivered to a source where it receives energy & emits radiation.

Radiation measured and correlated to concentration of analyte

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Non-essential elements are…

not needed for biological functions;

of medical interest for their toxic properties

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Essential elements…

have function in the body. Need to determine both deficiency and toxicity.

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Where does arsenic come from?

Natural substance in soil
Burning of fossil fuels
Agriculture uses
Contaminated ground water

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How are people exposed to arsenic?

Food, water, inhalation

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Forms of Arsenic

Inorganic (high toxicity)
Methylated (mild toxicity)
Organic (non-toxic)

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Preferred sample for Arsenic testing

Urine

blood has short half-life; hair and nails used for chronic/long-term exposure

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Symptoms of arsenic toxicity

GI symptoms
Bone marrow (pancytopenia, basophilic stippling)
CV, CNS, renal & hepatic problems

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skin manifestation of arsenic toxicity

lesions on hands, soles of feet

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Cadmium is absorbed primarily via ____

food

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Samples for cadmium testing

random/24 hour urine, blood

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Cadmium absorption higher in ____

females (related to iron stores)

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____ have 2x the cadmium as _____ (hint: lifestyle)

smokers; non-smokers

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Blood samples can be used to test for cadmium because ________

Cd binds to RBCs. Tested like HbA1C

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Cadmium toxicity causes:

Cancer
Hindered brain development in kids
Respiratory distress
renal dysfunction
also affects liver, bone, immune system and nervous system

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Mercury exposure occurs by:

Inhalation, ingestion, injection

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Toxicity occurs when mercury reacts with _________; binding _____ in proteins

sulfhydral groups;

cysteine

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Forms of mercury

Liquid environmental (non-toxic, but toxic in vapor form)
Inorganic (non-toxic)
Organic (toxic)

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Organic mercury is toxic due to…

Being highly selective for lipid-rich neurons

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S/S of mercury toxicity

Inhaled vapor: affects nervous, digestive & immune systems Inorganic exposure: skin, eyes, GI symptoms, kidneys

Lead is primarily absorbed by:

GI and respiratory tracts

Lead used to be used in:

Paints, gasoline

Once absorbed, lead distributed to:

Soft tissues of liver, kidney, brain

Sample(s) for lead testing

Venous whole blood most common. | Hair and nails also used.

S/S of lead toxicity

CNS: clumsy/abnormal gait, HA, seizures Neuropathy Anemia

Lead causes _____ of RBCs

basophilic stippling

Copper in body commonly found in ____

Metalloenzymes

Wilson's disease is copper ______

toxicity

Alpha-2 globulin that contains copper

Ceruloplasmin

What is Ceruloplasmin important in regulating?

Ionic states of Iron. Allows Fe to enter transferrin without forming toxic products.

What is Menkes Disease?

Fatally progressive brain disease caused by Copper deficiency.

What are common features of Menkes disease?

Kinky-steely hair, growth retardation. | Appears at 3 months, death at 5 years.

Disease of copper toxicity

Wilson's disease

Wilson's disease is a genetic condition resulting in ________ of copper

accumulation; | Copper gets deposited in tissues

Wilson's disease causes:

accumulation of copper in tissues; neurological and liver dysfunction; Kayser-Fleischer rings

What are Kayser-Fleischer rings? | What condition are they seen in?

Green-brown discoloration of cornea; | Wilson's disease

In Wilson's Disease, serum copper levels are _______ and urinary copper is ____

Decreased; increased.

Treatment of Wilson's disease

Penicillamine (binds copper)

Symptom's of Wilson's Disease:

Acute hemolytic anemia Neurologic syndrome Renal dysfunction (decreased GFR)

In Menkes, serum copper is _____ and urine copper is _______

decreased; increased

Zinc deficiency caused by:

old age, lactation, alcoholism, malnutrition

Zinc excess caused by:

Exposure to zinc fumes (zinc fume fever)

Zinc toxicity causes:

Pneumonia | Fever, cough, leg pain, chest pain, vomiting

Ionic states of iron:

Fe2: ferrous Fe3: ferric

Storage forms of iron

Ferritin | Hemosiderin

Transport form of iron

Transferrin

Normal body iron content:

4-5 grams, more than half in RBCs

T/F: Iron homeostasis is controlled by excretion rather than absorption

False. | Body rigorously conserves Fe- very little is lost. Regulates by absorption.

Dietary iron ingested in _____ form

Ferric (Fe3)

After iron is ingested, it must be ______ in stomach and then ______ in intestine.

reduced to Fe2; | oxidized to Fe3

_______ form of iron stored as ferritin

Ferric (Fe3)

Ferritin = _______ + _________

Ferric ion + apoferritin

If apoferritin quantities are insufficient to store iron, iron gets deposited into tissues as ________

hemosiderin

Usually only ____ of transferrin binding sites are used

1/3

T/F: Ferritin levels generally reflect total Fe stores in body

True (per Mitch)

Total iron refers to:

Fe3 bound to transferrin, not Fe circulating as free Hgb

Sample requirements for iron studies

serum or heparinized plasma | not EDTA or other anticoagulants

Why is EDTA not used to test for iron?

Binds iron. Only heparinized plasma should be used.

Iron in serum/plasma measured by:

Spectrophotometric methods

Steps for iron quantitation:

1. Release Fe3 from protein via acidification 2. Reduce Fe3 to Fe2 by ascorbic acid/reducing agent 3. Complex Fe2 with color reagent and measure

TIBC refers to:

amount of iron that could be bound by saturating transferrin and other binding proteins

Ferritin has ______ relationship with transferrin

Inverse

% iron saturation =

Serum Fe / TIBC * 100

Transferrin is a ______ acute phase protein

negative

Transferrin increased in ______

Iron deficiency

Transferrin decreased in ________

Iron overload, chronic infection, or malignancy

Ferritin increased in_______

iron overload, chronic infection, malignancy, viral hepatitis

Ferritin decreased in

iron deficiency

Iron Deficiency causes

Increased loss of iron Decreased intake/absorption Decreased release from ferritin Increased demand on body stores

``` Fe Deficiency results Total iron: Ferritin: Transferrin: TIBC: % Saturation: ```

``` Total: Decreased Ferritin: Decreased Trans: Increased (more available sites) TIBC: Increased % Sat: Decreased ```

Heme results from Fe deficiency

Decreased RBC ct. Micro/hypo Decreased MCH/MCHC

Iron overload referred to as:

Hemochromotosis

Hemochromotosis usually seen as a ________ condition

Hereditary (abn high Fe absorption)

Other causes of iron toxicity

Increased RBC destruction Decreased Fe utilization Increased absorption of iron Defective storage or release of iron

What does Hereditary hemochromotosis cause?

Tissue damage Hyperpigmentation of skin Hepatomegaly with liver dysfunction

HH treated by

phlebotomy or chelation

``` Iron toxicity lab results Total Iron: ferritin: Transferrin: TIBC: % Sat: ```

``` Total: Increased Ferritin: Increased Trans: decreased TIBC: decreased (binding sites used up) % sat: Increased ```

Multiple blood transfusions can cause ______ __________

iron overload

Chromium helps:

maintain normal metabolism of glucose, fat, and cholesterol

Chromium deficiency results in:

Diabetes-like hyperglycemia

Forms of Chromium

Cr(III): Essential | Cr(IV): toxic, carcinogen

Chromium in blood is bound to...

Transferrin

Cr(III) toxicity causes:

allergy-like reaction

Can see _____ Ca, AlkP & Phos in manganese deficiency

increase

Manganese deficiency can cause:

Blood clotting defects, hypocholesterolemia, dermatitis, epilepsy, heart and bone issues, stunted growth

Manganese toxicity can cause:

Nausea/vomiting, HA, memory loss, compulsive laughing & crying

Chronic Manganese deficiency may resemble:

Parkinson's

Molybdenum found in these foods:

peas, lentils, beans, grains, nuts

T/F: Molybdenum deficiency and toxicity are common

False. They're rare.

Molybdenum vital to ____ _______ in liver

sulfite oxidase (breaks down sulfite)

Production of uric acid requires this essential element:

Molybdenum

Selenium exposure happens via:

food and sometimes water

_____ is a constituent of glutathione

Selenium

Selenium is closely related with ____

Vitamin E

Keshan disease is:

Selenium deficiency affecting children and women of child-bearing age in China

Kashin-Beck is:

Endemic osteoarthritis in adolescent and preadolescents in northern China, N. Korea, and eastern Siberia. (areas with low soil selenium levels)

Selenium toxicity caused by:

Selenium sulfide- not found in foods. Possible carcinogen.