Question 1

The occurrence of cell membrane damage causing normal cells to be replaced with fibroblasts occurs in the heart because of a deficiency of which one of the following metals?

Accepted Answer

Selenium deficiency can lead to cell membrane damage, resulting in the replacement of normal cells with fibroblasts in the heart. This condition is associated with Keshan disease, a cardiomyopathy linked to selenium deficiency.

Question 2

All of the following factors must be demonstrated before metal toxicity is considered a diagnosis except:

Accepted Answer

According to the question, all factors must be demonstrated before metal toxicity is considered a diagnosis except for one. Therefore, the correct answer is the one that does not need to be demonstrated. Option B states that more than two organ systems must be affected, which is not a requirement for metal toxicity diagnosis, making it the correct answer. A source of metal exposure must be evident, typical metal overdose signs and symptoms must be shown, and abnormal metal concentration in the appropriate tissue must be evident in order to diagnose metal toxicity.

Question 3

Lead produces a serious toxic effect when ingested because it:

Accepted Answer

Lead interferes with the synthesis of heme by inhibiting the enzymes involved in the incorporation of iron into the porphyrin molecule, leading to anemia and other toxic effects.

Question 4

What blood analyte does a toxic overdose of aluminum affect?

Accepted Answer

A toxic overdose of aluminum affects the parathyroid hormone, leading to decreased levels of calcium in the blood by inhibiting its absorption from the gastrointestinal tract and increasing its excretion by the kidneys.

Question 5

MATCHING
Match the metal with the analytical issue that could alter the results of analysis.
-Chromium

Accepted Answer

Chromium is reduced to a nontoxic form in biological specimens.

Question 6

A byproduct of zinc and lead smelting,this metal is also used in the production of rechargeable batteries.Chronic exposure to this metal results in renal damage and breathing its fumes causes pulmonary congestion resembling chronic emphysema.

Accepted Answer

Cadmium is a byproduct of zinc and lead smelting and is used in the production of rechargeable batteries. Chronic exposure to cadmium can result in renal damage and pulmonary congestion resembling chronic emphysema. The other metals listed do not have these specific health effects associated with them.

Question 7

A four-member family of fish-loving vegetarians has become ill and visits their family practitioner.Their symptoms include stumbling (ataxia),visual field loss,and urinary difficulties.No Mees' lines are observed.Being environmentally conscious,they have their home examined for toxic gases.All tests are negative.Based on their history and symptoms,what toxic metal might be to blame?

Accepted Answer

The symptoms described are typical of mercury poisoning, which can be caused by the consumption of contaminated fish. The absence of Mees' lines rules out arsenic poisoning, and iron and cadmium toxicity do not typically cause these specific symptoms.

Question 8

Certain metals are essential for life at low concentrations and typically function as protein cofactors required for enzymatic reactions.These particular elements are located in which group(s)and row(s)of the periodic table?

Accepted Answer

The essential metals for life are typically transition metals, which are found in Groups 6 through 12 and Row 4 of the periodic table. These include elements such as iron, copper, zinc, and manganese, which are required for various biological functions such as oxygen transport, electron transfer, and DNA synthesis.

Question 9

Which one of the following is a toxic metal that produces Mees' lines upon overdose exposure by denaturing keratin in fingernails?

Accepted Answer

Arsenic is a toxic metal that, upon an overdose, can produce Mees' lines in fingernails. This is caused by the denaturation of the keratin in the nails. The other options listed are also toxic metals, but they do not cause Mees' lines in the same way that arsenic does.

Question 10

MATCHING
Match the metal with the analytical issue that could alter the results of analysis.
-Beryllium

Accepted Answer

Beryllium exposure is best assessed using a lymphocyte proliferation test, as serum or urine quantification is not useful for this metal.

Question 11

MATCHING
Match the metal with the analytical issue that could alter the results of analysis.
-Lead

Accepted Answer

Lead analysis often involves examining erythrocytes, for which EDTA-anticoagulated blood is the specimen of choice, as lead affects the blood system and accumulates in erythrocytes.

Question 12

An individual is admitted to the hospital with markedly increased liver enzymes (transferases)and unusual behavioral changes noted by her family.A protein electrophoresis reveals decreased ceruloplasmin.Which one of the following toxic metals might be implicated in this individual's symptoms?

Accepted Answer

The decreased ceruloplasmin levels suggest Wilson's disease, an inherited disorder of copper metabolism. The increased liver enzymes and behavioral changes are also commonly seen in this condition. Beryllium, aluminum, and lead toxicity do not typically present with this specific constellation of symptoms.

Question 13

In blood collection for chromium or other trace metal analysis,what aspect of specimen collection is critical?

Accepted Answer

Using specially manufactured collection tubes with unique stoppers is critical for blood collection for trace metal analysis. These tubes prevent contamination of the sample by trace metals from the stopper, which could interfere with the accuracy of the analysis. Timing of the blood draw, type of specimen (serum vs. plasma), and tourniquet use can also impact the accuracy of trace metal analysis, but using specialized tubes with appropriate stoppers is the most critical factor.

Question 14

When reporting the results of a urine metal analysis,such as urine chromium,how are the results reported?

Accepted Answer

Urine metal analysis results are typically reported in concentration units of the metal of interest per gram of creatinine. This is because urine creatinine levels can vary based on factors such as age, sex, and muscle mass. By standardizing the results to the amount of creatinine in the urine, the results can be more accurately interpreted and compared across individuals.

Question 15

MATCHING
Match the metal with the analytical issue that could alter the results of analysis.
-Arsenic

Accepted Answer

For analyzing arsenic, urine specimens are best and blood specimens are not very useful.

Answer: A
 When examining arsenic in biological specimens, it is important to reduce it to a nontoxic form to avoid altering the results of analysis.

Answer: C
 In order to analyze the lymphocyte proliferation test, a serum or urine quantification is not useful, so a lymphocyte proliferation test is required.

Answer: D
 When examining arsenic in erythrocytes, EDTA-anticoagulated blood is the specimen of choice.

Question 16

A four-member family of vegetarians has become ill and visits their family practitioner.Their symptoms include stumbling (ataxia),visual field loss,and urinary difficulties.No Mees' lines are observed.Based on their symptoms and knowledge of the correct metal involved,what is the best therapy?

Accepted Answer

The answer of A four-member family of vegetarians has become...

Question 17

Both mercury and arsenic produce their symptoms of toxicity in a similar way.This includes:

Accepted Answer

Both mercury and arsenic bind to sulfhydryl groups on proteins, causing loss of protein activity and leading to toxicity. This is a common mechanism of toxicity for both substances. Choices A, B, and D are not accurate mechanisms of toxicity for mercury and arsenic.

Question 18

What is the specimen of choice for determining arsenic exposure in an individual and why?

Accepted Answer

Urine is the specimen of choice because arsenic is excreted predominantly by the kidneys and urine can provide a measure of recent exposure. Urine levels can indicate exposure within the past 1-3 days, while blood levels can only indicate exposure over a shorter period of time (i.e. up to 48 hours). Serum and plasma are not considered ideal specimens for arsenic exposure assessment.

Quiz 32: Toxic Metals

The occurrence of cell membrane damage causing normal cells to be replaced with fibroblasts occurs in the heart because of a deficiency of which one of the following metals?

All of the following factors must be demonstrated before metal toxicity is considered a diagnosis except:

Lead produces a serious toxic effect when ingested because it:

What blood analyte does a toxic overdose of aluminum affect?

MATCHING Match the metal with the analytical issue that could alter the results of analysis. -Chromium

A byproduct of zinc and lead smelting,this metal is also used in the production of rechargeable batteries.Chronic exposure to this metal results in renal damage and breathing its fumes causes pulmonary congestion resembling chronic emphysema.

Certain metals are essential for life at low concentrations and typically function as protein cofactors required for enzymatic reactions.These particular elements are located in which group(s) and row(s) of the periodic table?

Which one of the following is a toxic metal that produces Mees' lines upon overdose exposure by denaturing keratin in fingernails?

MATCHING Match the metal with the analytical issue that could alter the results of analysis. -Beryllium

MATCHING Match the metal with the analytical issue that could alter the results of analysis. -Lead

An individual is admitted to the hospital with markedly increased liver enzymes (transferases) and unusual behavioral changes noted by her family.A protein electrophoresis reveals decreased ceruloplasmin.Which one of the following toxic metals might be implicated in this individual's symptoms?

In blood collection for chromium or other trace metal analysis,what aspect of specimen collection is critical?

When reporting the results of a urine metal analysis,such as urine chromium,how are the results reported?

MATCHING Match the metal with the analytical issue that could alter the results of analysis. -Arsenic

A four-member family of vegetarians has become ill and visits their family practitioner.Their symptoms include stumbling (ataxia) ,visual field loss,and urinary difficulties.No Mees' lines are observed.Based on their symptoms and knowledge of the correct metal involved,what is the best therapy?

Both mercury and arsenic produce their symptoms of toxicity in a similar way.This includes:

What is the specimen of choice for determining arsenic exposure in an individual and why?