1
Q
An element is considered _____ if a deficiency impairs a biochemical or functional process.
A
Essential
2
Q
What would be the treatment for the deficiency of an essential element?
A
Replacement
3
Q
This type of trace element is of medical interest primarily because many of them are toxic.
A
Nonessential
4
Q
The essential trace elements are often associated with an enzyme called _____ or a protein called _____ as a cofactor.
A
Metalloenzyme
Metalloprotein
5
Q
This is a crystalline, silver-white ductile metal.
It is the most abundant metal on earth.
A
Aluminum (Al)
6
Q
The human body absorbs how much of inhaled aluminum?
A
1.5% - 2%
7
Q
The human body absorbs how much of ingested (orally taken) aluminum?
A
0.01% - 5%
8
Q
The absorption efficiency of aluminum is dependent on what factors?
A
Chemical form
Particle size
Dietary exposure to chelators
9
Q
What are the chelating agents to aluminum?
A
Citric and Lactic acid
10
Q
In plasma, Al is bound to carrier proteins such as _____.
A
Transferrin
11
Q
Al binds to various _____ in the blood and distributes to every organ.
A
Ligands
12
Q
How much of the Al in the body is found in the bone?
A
50%
13
Q
How much of the Al in the body is found in lung tissue?
A
25%
14
Q
How much of the Al in the body is excreted through urine?
A
95%
15
Q
How much of the Al in the body is excreted in the bile?
A
2%
16
Q
The amount of Al in this body organ increases with age.
A
Lungs
17
Q
This trace element has been shown to interfere with enzymatic processes and will produce encaphalopathy in animals.
A
Aluminum
18
Q
What are the signs and symptoms of Al toxicity?
A
Encephalopathy Osteomalacia/aplastic bone disease (painful spontaneous fractures, hypercalcemia, and tumor calcinosis) Proximal myopathy Increased risk of infection Microcytic anemia Increased left ventricular mass Decreased myocardial function
19
Q
What are the clinical manifestations of Al toxicity?
A
Anemia
Bone disease
Progressive dementia with inc. conc. of Al in the brain
20
Q
Al toxicity can cause what disease in infants?
A
Impaired neurologic development
21
Q
This is a ubiquitous element displaying both metallic and non-metallic properties.
A
Arsenic (As)
22
Q
This is the largest source of As exposure for most people.
A
Food
23
Q
What is the main current use of As?
A
Wood preservative
24
Q
Enumerate other current and past uses of As.
A
Pesticides Pigments Poison gases Ammunition manufacturing Semiconductor proecessing Medicines
25
The clinical signs and symptoms of As exposure depends on these factors.
Duration and extent of exposure to organic and methylated species of As
Underlying clinical status of patient
26
What are the symptoms for acute As exposure?
Gastrointestinal (nausea, emesis, abdominal pain, rice water diarrhea)
Bone marrow (Pancytopenia, anemia, basophilic stippling)
Cardiovascular (ECG changes)
CNS (Encephalopathy, polyneuropathy)
Renal (Renal insufficiency, renal failure)
Hepatic (Hepatitis)
27
What are the symptoms for chronic As exposure?
Dermatologic (Mees' line, hyperkeratosis, hyperpigmentation, alopecia)
Hepatic (Cirrhosis, hepatomegaly)
Cardiovascular (Hypertension, peripheral vascular disease [PVD])
CNS ("Socks and gloves" neuropathy, tremor)
Malignancies (Squamous cell, hepatocellular, skin, bladder, lung, renal carcinoma)
28
What are the symptoms for chronic As exposure specifically concerning the CNS?
"Socks and gloves" neuropathy
| Tremor
29
Chronic exposure to As has been shown to cause _____, a severe form of PVD which leads to gangrenous changes.
Blackfoot disease
30
What are the dermatological symptoms for chronic As exposure?
Mees' line
Hyperkeratosis
Hyperpigmentation
Alopecia
31
What are the chelating agents for As poisoning?
Dimercaprol (aka. British anti-Lewisite)
Penicillamine
Succimer
32
Arsenic trioxide can be used for the treatment of what disease?
Acute Promyelocytic leukemia
33
What are the main routes for As exposure?
Ingestion
| Inhalation
34
What are the organic forms of As?
Arsenocholine
| Arsenobetaine
35
This form of As is commonly found in fish and seafood , are considered relatively non-toxic, and are cleared rapidly.
Organic form
36
This form/species of As are highly toxic and occur naturally in rocks, soil, and groundwater.
Inorganic form
37
This form/species of As are intermediate in toxicity and arise primarily from metabolism of inorganic As, but small amounts may arise from food.
Methylated
38
Give examples of organic methylated As compounds.
```
Monomethylarsonic acid (MMA)
Dimethylarsenic acid (DMA)
```
39
This organic methylated arsenic compound was formed by the hepatic metaolism of As(3+).
Monomethylarsonic acid (MMA)
40
This organic methylated arsenic compound was formed by the hepatic metaolism of As(5+).
Dimethylarsenic acid (DMA)
41
(T/F) Inorganic methylated forms are more toxic than its organic counterparts and they are eliminated slowly, usually 1 - 3 weeks.
F (Inorganic less toxic than organic (As3+ and As 5+)
42
This is a soft bluish-white metal that can be easily cut with a knife.
Cadmium (Cd)
43
What are the most common uses of Cd?
Manufacture of pigments, batteries, metal plating, plastic
44
What is the largest source of airborne Cd exposure?
Burning of fossil fuel
| Incineration of municipal waste
45
What is the chelating agent for Cd exposure/
EDTA
46
What is the reference dose for Cd in drinking water?
0.0005 mg/kg/d
47
What is the reference dose for dietary exposure to Cd?
0.001 mg/kg/d
48
Absorption of Cd is (higher/lower) in females than in males due to differences in iron stores.
Higher
49
How much of inhaled Cd is absorbed in the body?
10-50%
50
For nonsmokers, what is the primary source of Cd exposure?
Ingested food
51
A what percent of the ingested Cd is excreted in the feces due to the low absorbance of Cd from the gut?
90%
52
Inhaled Cd can cause what toxic effects?
```
Respiratory distress
Lung damage (Emphysema-like symptoms)
```
53
Acute Cd exposure can cause what toxic effects?
Nausea
Vomiting
Abdominal pain
54
Chronic Cd exposure can cause what toxic effects?
Slow onset of preteinuria
55
The toxicity of Cd is believed to be a result of _____ causing denaturation of the associated proteins, resulting in a loss of function.
Protein-Cd adducts
56
This element comes from the Greek word chroma meaning color.
Chromium (Cr)
57
This is the 21st most abundant element
Cr
58
What are the most common uses of Cr?
```
Manufacturing stainless steel
Wood treatment
Chrome plating
Leather tanning
Lead chromate or strontium chromate paints
```
59
What are the two main valencies of Cr?
```
Trivalent Cr(3+)
Hexavalent Cr(6+)
```
60
(T/F) Cr(6+) is better absorbed and much more toxic that Cr(3+)
T
61
This element is responsible for the red color of rubies and the green color of emerald.
Chromium (Cr)
62
This proteins bind the newly absorbed Cr at site B.
Transferrin
63
This as an acceptor and transporter of Cr when transferrin sites are saturated.
Albumin
64
Aside from transferrin and albumin, enumerate other plasma proteins that can bind Cr.
Beta-globulins
Gamma-globulins
Lipoproteins
65
This element is an essential dietary element and plays a role in maintaining normal metabolism of glucose, fat, and cholesterol..
Chromium (Cr(3+))
66
What is the estimated safe and adequate daily intake of Cr for adults?
50 - 200ug/d
67
Intracellularly, this valence state of CR is reduced to reactive intermediates, producing free radicals and oxidizing deoxyribonucleic acid (DNA), both potentially inducing cell death.
Cr(6+)
68
What is the primary means for Cr to enter the body?
Ingestion
| Inhalation
69
What is the mode of excretion of Cr?
Urine
70
Cr deficiency is characterized by what conditions?
```
Glucose inteolerance
Glycosuria
Hypercholesterolemia
Decreased longevity
Decreased sperm counts
Impaired fertility
```
71
Contact with Cr(6+) salts can induce what conditions?
Severe dermatitis
| Skin ulcers
72
Cr(3+/6+)-protein complex is responsible for allergic reactions due to Cr toxicity
Cr(3+)
73
(Low/High)-dose, (chronic/acute) Cr exposure typically results in transient renal effects.
Low
| Chronic
74
This element is known to be a soft yet tough metal with excellent electrical and heat conducting properties.
Copper (Cu)
75
What are the four oxidation states of Cu?
Cu(0-3+)
76
Among the oxidation states of Cu, what is the most stable?
Cu(2+)
77
This element is an importnant cofactor for several metalloenzymes and is critical for reduction of iron in heme synthesis.
Copper (Cu)
78
How much of ingested copper is absorbed from the intestines?
50% - 80%
79
What is the average daily intake of Cu?
10 mg or more
80
At low concentrations, how is copper transported by the intestines?
Active transport
81
At high concentrations, how is copper transported by the intestines?
Passive transport
82
In the liver, copper is incorporated into _____ for ditribution throughout the whole body.
Ceruloplasmin
83
98% of copper is excreted by the _____ and the other 2% is excreted through _____ and _____.
Bile
| Urine and sweat
84
Copper deficiency is observed in premature infants and copper absorption is impaired in what clinical conditions?
Sever diffuse diseases of small bowel
Lymphosarcoma
Scleroderma
85
An extreme form of copper deficiency can be seen in _____ disease, with symptoms usually appear at the age of 3 months and death occuring at the age of 5.
Menkes
86
What are the signs of Cu deficiency?
Neutropenia and Hypochromic anemia in the early stages
Osteoporosis and various bone and joint abnormalities
Decreased pigmentation of the skin and general pallor
Neurologic abnormalities in the late stages (Hypotonia, apnea, psychomotor retardation)
87
What color is exhibited in Cu-induced emesis?
Blue-green
88
This is a genetically determined Cu-accumulation disease that usually present between the ages of 6 - 40 years old.
Wilson's disease
89
What are the clinical findings when a patient is suffering from copper deposition? (Wilson's disease)
Neurologic disorders
Liverdysfunction
Kayser-Fleischer rings (green-brown discoloration) in the cornea
90
What treatments can be done to stop Wilson's disease?
Zinc acetate
| Chelation therapy
91
These are key diagnostic steps in diagnosing Wilson's disease.
Serum ceruplasmin levels
| Direct measurement of free copper
92
This is the 4th most abundant metal and the most abundant transitional metal
Iron (Fe)
93
What are the two valence forms of Fe that are able to partcipate in redox chemistry?
Ferrous (Fe(2+))
| Ferric (Fe(3+))
94
Ferrous (Fe(2+)) and Ferric (Fe(3+)) states allows iron to fill numerous biochemical roles such as _____ and _____.
Carrier of other biochemically active substances
| Agent in redox and electron transfer reaction (eg. via various cytochromes)
95
This type of Fe in the body participates in destructive chemistry, primarily in catalyzing the formation of toxic free radicals.
Free iron
96
This is the primary means of regulating the amount of iron within the body.
Absorption of Fe in the intestines
97
To be absorbed by intestinal cells, iron must be _____ and _____.
```
In ferrous (Fe2+) oxidation state
Bound to protien
```
98
This is the predominant form of Fe in food.
Ferric (Fe3+)
99
What agents in the intestinal epithelium reduces Fe(3+) to Fe(2+) state?
Vitamin C
| Ferric reductases
100
What peptide hormone regulates iron absorption in the upper gastrointestinal tract by modulating the export of iron from cells by ferroportin.
Hepcidin
101
Absorption and transport capacity of iron can be increased in conditions such as _____ ...
Iron deficiency
Anemia
Hypoxia
102
Iron is lost primarily by _____ and _____.
Desquamation and red cell loss to urine and feces
103
How much iron is present in the human body?
3-5g
104
Of the total Fe in the body, how much is present in hemoglobin, mostly in RBCs and red cell precursors?
2-2.5g
105
Of the total Fe in the body, how much is present in myoglobin, the oxygen carrying protein of the muscle?
~130mg
106
This is the oxygen carrying protein of the muscle?
Myoglobin
107
Of the total Fe in the body, how much is bound to tissue enzymes that require iron for full activity?
8mg
108
Enumerate some enzymes that require iron for full activity.
Peroxidases
Cytochromes
Many of the Krebs cycle enzymes
109
Iron is stored as _____ and _____, primarily in the bone marrow, spleen and liver.
Hemosiderin
| Ferritin
110
This is a protein that transports Fe to the different parts of the body.
Apotransferrin
111
How much of iron is excreted through menstrual cycle?
20-40mg
112
Enumerate those that have a higher than average risk of acquiring iron deficiency anemia.
Pregnant women
Young children
Adolescents
Women of reproductive age
113
These conditions may result in iron deficiency anemia.
Increased blood loss
Decreased dietary iron intake
Decreased released from ferritin
114
A decrease in these lab results would indicate iron deficiency anemia.
RBC count
MCHC
Microcytic RBCs
115
Iron overload states are collectively referred to as _____.
Hemochromatosis
116
Primary iron overload is most frequently associated with what disease?
Hereditary Hemochromatosis (HH)
117
This is a single-gene homozygous recessive disorder leading to abnormally high Fe absorption, culminating in Fe overload.
Hereditary Hemochromatosis (HH)
118
What effects can Hereditary Hemochromatosis (HH) have?
Tissue accumulation of Fe
Affects liver function
Often leads to hyperpigmentation of the skin caused by slight decrease in transferrin
119
What condition are associated with severe hemochromatosis?
```
Diabetes mellitus
Arthritis
Cardiac arrhythmia or failureCirrhosis
Hypothyroidism
Impotence
Liver cancer
```
120
What is the treatment for Fe overload?
Therapeutic phlebotomy or administration of chelators, such as deferoxamine
121
What chelator is used for the treatment of Fe overload?
Deferoxamine
122
This iron related disease may result from excessive dietary, medicinal, or transfusional Fe intake or due to metabolic dysfunction.
Secondary Fe overload
123
This condition has been used to specifically designate a condition of iron overload as demonstrated by an increased serum iron and total iron-binding capacity (TIBC) or transferrin, in the absence of demonstratable tissue damage.
Hemosiderosis
124
This element is soft, bluish white, highly malleable, and ductile. It is a poor conductor of electricity and heat and us resistant to corrosion.
Lead (Pb)
125
What are the most common uses of lead (Pb)?
Production of storage batteries, ammunition, solder, and foils, crayons and children's toys.
126
What substances can weaken lead absorption?
```
Iron
Calcium
Magnesium
Alcohol
Fat
```
127
What factors can enhance lead absorption?
Low dietary zinc, ascorbic acid, and citric acid
128
About 99% of lead is taken up by _____ where it interferes with heme synthesis.
Erythrocytes
129
How much of absorbed lead is excreted in the urine?
76%
130
How much of absorbed lead is excreted in the feces?
16%
131
How much of absorbed lead is excreted in the hair, sweat, and nails?
8%
132
Blood lead levels greater than or equal to ___ug/dL in children can lead to a decrease in IQ.
10
133
Lead toxicity exhibits this characteristic property in the blood film.
Basophilic stippling
134
This element is a heavy, silvery metal also called quicksilver.
Mercury (Hg)
135
Along with bromine, it is one of two elements that are liquid in room temperature.
Mercury (Hg)
136
What are the three naturally occurring oxidation states of mercury?
Hg(0-2+)
137
What are the most common uses of Hg?
```
Dental amalgrams
Electronic switches
Germicides
Fungicides
Fluorescent light bulbs
```
138
Enumerate over-the-counter drugs that contain Hg.
```
Topical antiseptics
Stimulant laxatives
Diaper-rash ointment
Eye drops
Nasal sprays
Eye cosmetics, mascara
```
139
What are the routes of exposures of mercury?
Inhalation, elemental Hg vapor
Ingestion of HgCl2 and mercury containing foods (fish)
Cutaneous absorption of methyl mercury (MeHg) through the skin and latex gloves
Injection of relatively inert liquid mercury/ mercury-containing tattoo pigments
Dental amalgrams
140
Lead in the body is eliminated in approximately how many days?
60 days
141
This type of mercury can accumulate in the brain and may take up to several years to be eliminated.
Organic mercury
142
What are the main elimination routes for lead?
Feces
| Urine
143
(T/F) Organic and elemental mercury vapor are toxic to only the CNS and not the peripheral NS
F (Toxic to both CNS and peripheral nervous system
144
The inorganic salts of mercury can affect what parts of the body?
Skin
Eyes
Gastrointestinal tract
Kidneys
145
The toxicity of mercury is primarily through reaction with _____, resulting in dysfunction and inactivation.
Protein sulfhydryl groups (MSH)
146
This type of Hg is poorly absorbed and relatively nontoxic.
Liquid elemental Hg
147
Inorganic, ionized forms of mercury are (toxic/nontoxic).
Toxic
148
This is an alkyl Hg that yields a very toxic (most toxic) species of Hg that is highly selective for lipid-rich mediums such as the brain.
Methyl Hg (MeHg)
149
This type of Hg binds with cysteine and can cross the blood-brain barrier causing an accumulation of Hg in the brain
Methyl Hg (MeHg)
150
This is the 12th most abundant element in the earth's crust.
Manganese (Mn)
151
What are the most common uses of Mn?
Fertilizers
Animal feeds
Dyes
Paint dryers
152
Of the dietary manganese, how much is absorbed in the small intestine?
2-15%
153
Mn absorption is age dependent, with infants retaining (higher/lower) levels of Mn than adults.
Higher
154
Highest levels of Mn can be found in what tissues/parts of the body?
Fat
| Bone
155
Mn elimination occurs predominantly through the _____.
Bile
156
What are the functions of Mn?
Constituent of metalloenzymes
| Enzyme activator
157
Enumerate some Mn containing enzymes
Arginase
Pyruvate carboxylase
Mn superoxidase dismutase in the mitochondria
158
Enumerate some Mn activated enzymes
Hydrolases
Kinases
Decarboxylases
Transferases
159
Enumerate conditions that can be observed in people who have Mn depletion.
Blood clotting defects
Hypocholesterolemia
Dermatitis
Elevated serum calcium, phosphorus, and alkaline phosphatase activity
160
What conditions have been associated with low levels of Mn?
```
Epilepsy
Stunted growth
Hip abnormalities
Joint disease
Congenital malformation
Heart and bone problems
```
161
Chronic Mn toxicity resembles what disease?
Parkinson's disease with akinesia, rigidity, tremors and mask-like faces
162
This condition is a result of acute Mn aerosol intoxication.
Locura manganica (Mn madness)
163
This element is a hard, silvery white metal most commonly used in corrosion inhibitors, flame retardants, and smoke depressants.
Molybdenum (Mo)
164
What are the three types of Molybdenum (Mo)?
Molybdenite
Wulfenite
Powelite
165
Absorption of 25% - 80% of ingested Mo occurs predominantly in the _____ and _____.
Stomach
| Small intestine
166
Majority of absorbed Mo is retained in what organs?
Liver
Skeleton
Kidney
167
In blood, Mo is bound to _____ and _____.
alpha2-macroglobulin
| RBC membranes
168
(T/F) Mo can cross the placental barrier
T
169
Enumerate the three enzymes containing Mo
Xanthine oxidase
Aldehyde oxidase
Sulfite oxidase
170
Mo is eliminated through _____ and _____.
Urine
| Bile
171
High dietary and occupational exposures to Mo have been linked to what conditions?
Elevated uric acid in blood
| Increased incidence of gout
172
This is a naturally occurring metalloid with many chemical and physical properties similar to those of sulfur.
Selium (Se)
173
WHat are the most common uses of Se?
Nutritional supplements
Rubber production
Anti-dandruff shampoo
174
What is the biologic function of Se?
Cellular antioxidant
| Metabolism of thyroid hormones
175
Where does absorption of Se occur?
Gastrointestinal tract (~50%)
176
How is Se excreted from the body?
Via urine, feces, sweat and exhalation of volatile forms
177
Glutathione peroxidase in the form of _____, is part of the cellular antioxidant defense system against free radicals. Se is also involved in the metabolism of thyroid hormones
Selenocysteine
178
This is a disease associated with Se deficiency and is an endemic cardiomyopathy that affects mostly children and women in childbearing age in certain areas in China.
Keshan disease
179
What is the treatment for Keshan disease?
Selenium supplementation
180
This is a disease associated with Se deficiency and is an endemic osteoarthritis that occurs during adolescent and preadolescent years.
Kashin-Beck disease
181
Acute oral exposure to extremely high levels of Se may produce what symptoms?
```
Gastrointestinal symptoms (nausea, vomiting, diarrhea)
Cardiovascular symptoms (Tachycardia)
```
182
Chronic exposure to very high levels of Se can cause what effects?
Deram effects, including diseased nails and skin, hair loss
| Neurologic problems such as unsteady gait or paralysis
183
What form of Se is carcinogenic?
Selenium sulfide
184
This is a bluish white lustrous metal that is stable in dry air and becomes covered with a white coating when exposed to moisture.
Zinc (Zn)
185
What are the most common uses of Zn?
```
Production of alloys, especially brass (with copper)
Galvanizing steel
Die casting
Paints
Skin lotions
Treatment for Wilson's disease
```
186
Absorption of Zn mainly occurs in what organ?
Small intestine, specifically jejunum
187
What percent of Zn is absorbed in the muscle?
60%
188
What percent of Zn is absorbed in the skeletal system?
30%
189
What percent of Zn is absorbed in the eyes, prostate, hair and other tissues?
10%
190
In blood, what percent of Zn is located in the RBCs?
80%
191
In blood, what percent of Zn is located in the plasma?
17%
192
In blood, what percent of Zn is located in the white blood cells?
3%
193
Enumerate factors that can increase Zn absorption.
Presence of animal protein and amino acids in a meal
| Intake of calcium and unsaturated fatty acids
194
Enumerate factors that can decrease Zn absorption.
Intake of iron
Taking Zn on an empty stomach
Presence of copper at high levels
Age
195
The main biochemical role of this element is seen in its influence on the activity of more than 300 enzymes
Zinc (Zn)
196
Enumerate conditions that are caused by Zn deficiency.
Growth retardation
Slows skeletal maturation
Causes testicular atrophy
Reduces taste perception
197
Infants with this disease first develop a characteristic facial and diaper rash. If untreated, may progress and include growth retardation, diarrhea, impaired Tcell immunity, insufficient wound healing, infections, delayed testicular development in adolescence, and early death
Acrodermatitis enteropathica (Zn malabsorption)
198
Zn deficiency in (infants/adolescence) is manifested by slow growth or weight loss, altered taste, delayed puberty, dwarfism, impaired dark adaptation, alopecia, emotional instability and tremors.
Adolescence
199
High doses (1g) or repetitive doses of 100mg/d of Zn for several months may lead to what conditions?
Gastrointestinal tract symptoms
Decrease in heme synthesis due to an induced copper deficiency
Hyperglycemia
200
Exposure to ZnO fumes and dust may cause this disease with symptoms including chemically induced pneumonia, severe pukmonary inflammation, fever, hyperpnea, coughing, pains in legs and chest, and vomiting
Zinc fume fever
201
What are the essential trace elements?
```
Cr
Fe
Mn
Se
Mo
Zn
```
202
What are the nonessential trace elements?
```
Al
As
Cd
Pb
Hg
```
