Trace/toxic Elements Flashcards
(74 cards)
1
Q
Essential element
A
If a deficiency impairs a biochemical or functional process and replacement of the element corrects this impairment
2
Q
Trace elements vs ultratrace elements
A
- Trace = needed in mg/dl
- Ultratrace = needed in microgram/dl
3
Q
Non-essential trace elements
A
Many are toxic and are thus of medical interest
4
Q
List 5 important factors of elements that are important to the clinical significance of disease states or toxicity
A
- Absorption
- Transport
- Distribution
- Metabolism
- Elimination
5
Q
Which blood collection tube is used for sample collection/processing upon suspicion of trace elements?
A
Royal blue stopper with or without EDTA
6
Q
List trace element analytical methods
A
- Atomic emission spectroscopy
- Atomic absorption spectroscopy
- Inductively coupled plasma mass spectrometry
7
Q
Atomic emission spectroscopy
A
- Quantify element by measuring intensity of emitted radiation from aerosolized sample
- Setup similar to spectrophotometer (flame or plasma -> light emission -> monochromator -> detector)
8
Q
Atomic absorption spectroscopy
A
- Quantify element by measuring absorption of optical radiation by free atoms in gas phase
- Setup similar to spectrophotometer
9
Q
Atomic absorption spectroscopy light sources
A
- Usually hollow cathode lamps (HCLs) and electrodeless discharge lamps (EDLs)
- Flame and graphite furnaces most common sources
10
Q
ID the element
Most abundant metal in earth’s crust
Widely used in industrial and household ways
Corrosion-resistant
Lightweight
A
Aluminum
11
Q
Aluminum mode of absorption
A
- Ingestion
- Inhalation
- Parenteral
- NOT TRANSDERMAL
12
Q
What percent of aluminum concentrates in bone and lung?
A
50% bone and 25% lung
13
Q
Aluminum health effects and toxicity
A
- Interferes with enzyme activity
- Encephalopathy, anemia, bone disease, progressive dementia
14
Q
ID the element
Both metallic and non-metallic properties
In pesticides, pigments, manufacturing processes (wood-preservation)
Odorless/tasteless
A
Arsenic
15
Q
Arsenic’s largest source of exposure
A
Food
One of the most common poisons in history
16
Q
Arsenic absorption/transport
A
- Ingestion and inhalation
- Hepatic metabolism
17
Q
Clearance of organic versus inorganic arsenic
A
- Organic arsenic rapidly cleared
- Inorganic and methylated forms are toxic
18
Q
ID the element
Found in rice
Soft, bluish-white metal - can be cut with knife
Used in industry, contaminates soil
A
Cadmium
19
Q
Cadmium absorption
A
- Ingestion (5%)
- Inhalation (10-50%)
- Higher in females + smokers than males + non-smokers bc iron stores different
20
Q
Urine accounts for ___% of cadmium excretion and __% in bile
A
- 95%
- 2%
21
Q
Cadmium health effects and toxicity
A
- No role in human physiology
- Affects liver, bone, immune system, blood, pulmonary, and nervous systems (everything)
22
Q
ID the element
Used in making stainless steel
Has essential and toxic forms based on oxidation state
A
Chromium
23
Q
Chromium absorption/transport
A
- Ingestion
- Inhalation
- Skin
- Transported bound to albumin and transferrin
24
Q
Which forms of cadmium are essential or toxic?
A
Cr3+ is essential
Cr6+ is toxic and easier to absorb
25
Chromium health effects
- Lung irritation and dermatitis more common
- Liver, kidney, and immune system
26
**ID the element**
Relatively soft yet tough metal
Excellent electrical and heat conducting
Important cofactor for reduction of iron in heme synthesis
Copper
27
Copper absorption/transport/excretion
- Ingestion
- Inhalation
- Dermal
- Transported bound to albumin
- Bile accounts for 98% excretion, <3% in urine/sweat
28
Copper health effects and toxicity
- Important for many metalloenzymes
- Hepatic and renal damage
- Neurologic symptoms
- Mucous membrane irritant
- **Wilson's disease** copper rings in eyes
29
Serum and urine copper levels in Wilson's disease
Serum = normal or decreased
Urine = increased
30
Iron absorption
Ingestion (10% ingested is absorbed)
Ferric form must be reduced to Ferrous for absorption
31
Iron transport
Bound to proteins (ferritin)
32
Iron excretion
- Primarily by desquamation of epithelia
- RBC loss in urine/feces
- Menstruation
33
Iron health effects and toxicity
- Important for Hgb, Mgb, and enzymes
- Deficiency and overload states possible
- Stored as ferritin and hemosiderin in BM, spleen, and liver
- Iron deficiency in 15% world population
34
Lab eval of iron status
- Hgb
- RBC indices
- Total Fe
- TIBC
- % sat
- Transferrin
- Ferritin
35
Serum iron
Refers to ferric iron bound to transferrin, NOT the free iron circulating in plasma
36
Serum iron collection
Early morning collection preferred due to **diurnal variation**
No visible hemolysis
37
Transferrin
Primary plasma iron transport protein, which binds iron
38
Transferrin saturation
25-30%
39
Unsaturated iron binding capacity (UIBC)
Additional amount of iron that can be bound (empty binding sites left on transferrin)
40
Total iron binding capacity (TIBC)
Theoretical amount of iron that could be bound if transferrin and other minor iron-binding proteins present in serum/plasma were saturated
41
TIBC calculation
TIBC = transferrin X 1.18
42
Percent saturation
- Transferrin saturation
- Ratio of serum iron to TIBC
- % sat = 100 X serum iron/TIBC
43
Ferritin
Major iron storage protein
44
Concentration of ferritin is directly proportion to what?
Total iron stores in body
45
More sensitive and reliable test for iron deficiency
Ferritin
46
Iron deficiency serum iron, transferrin, ferritin, percent sat, and TIBC relative values
Serum iron = lower
Transferrin = higher
Ferritin = lower
Percent sat = lower
TIBC = higher
47
Iron overdose serum iron, transferrin, ferritin, percent sat, and TIBC relative values
Serum iron = higher
Transferrin = lower
Ferritin = higher
Percent sat = higher
TIBC = lower
48
**ID the element**
Soft, bluish-white, highly malleable/ductile
Used to be put in gas and paint
Lead
49
Lead absorption
- Ingestion and inhalation
- 99% absorbed by RBC
- Liver, kidney, and brain with highest in bone (90%)
50
Lead excretion
- 76% urine
- 16% feces
- Remainder in sweat, hair, and nails
51
Lead health effects and toxicity
- No physiological role
- Higher absorption in kids
- Neurological symptoms and low IQ
- Anemia
52
**ID the element**
Used in production of steel
Manganese
53
Manganese absorption
- Mainly ingestion
- Inhalation and dermal limited
- Found mostly in fat and bone
54
Manganese excretion
Bile accounts for majority of excretion
55
Manganese health effects
Important for many metalloenzymes and enzyme activation
56
Manganese deficiency effects
Clotting issues, dermatitis, elevated serum Ca/phosph/ALP
57
Manganese toxic effects
Nausea, vomiting, headache, disorientation, anxiety, compulsive laughing or crying (manganese madness)
58
**ID the element**
Quicksilver, heavy/silvery metal, liquid at room temp
3 oxidation states
Mercury
H^0, Hg1+, Hg2+
59
Mercury absorption
- Inhalation most common
- Ingestion, cutaneous, injection, and dental
60
Mercury major storage organ
Kidney
61
Mercury excretion
Fecal and urinary
62
Mercury health effects an toxicity
- No physiologic role
- CNS and PNS toxicity
- Can damage most organs/tissues before symptoms occur
63
Molybdenum absorption
- Up to 80% by ingestion
- Mainly liver, skeleton, kidneys
64
Molybdenum bound to
Alpha-macroglobulin and RBC membranes
65
Molybdenum excretion
Urinary
66
Molybdenum health effects and toxicity
- Important cofactor for several enzymes
- Deficiency and toxicity rare
67
**ID the element**
Used in electronic industry, nutritional supplements, pigments, pesticides, dandruff shampoos, and fungicides
Selenium
68
Selenium absorption
Ingestion most common (up to 50% of diet)
69
Selenium excretion
- Mainly urine
- Some in sweat and exhalation
70
Selenium health effects and toxicity
- Important antioxidant
- Thyroid hormone synthesis
- Deficient states -> cardiomyopathy
- Toxic states -> GI, tachycardia, CNS symptoms
71
**ID the element**
Bluish-white lustrous metal
Stable in dry air
Covered in white coating upon moisture exposure
Zinc
72
Zinc absorption
- Ingestion most common
- Mainly muscle (60%) and bone (30%)
- RBCs absorb most zinc in blood (80%)
73
Zinc excretion
Feces
74
Zinc health effects and toxicity
- Important for enzyme activity, DNA/RNA, membrane structure...etc
- Deficiency -> growth inhibition, testicular atrophy
- Toxicity rare
- Counteracts copper in Wilson's disease
