LEC10 - TRACE ELEMENTS - Iron-Zinc Flashcards by CHARLENE SAN JOSE

4th most abundant element in the earth’s crust

iron - FE

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most abundant transition metal

iron

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iron participates in the following:

oxygen transport
redox chemistry in both ferrous and ferric states
agent in redox and electron transfer reactions

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do FE has magnetic properties?

yes - that is why it is an element added to make steel

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Iron’s high activity is a double- edged sword, and free iron
ions in the body also participate in destructive chemistry,
primarily in catalyzing the formation of ______

toxic free radicals.

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about how many percent of iron are absorbed in dietary per day

10% of the approx 10-20 mg/day of dietary iron

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how intestinal cells absorbed iron

iron must be in ferrous 2+ oxidation state and bound to protein

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2 forms of iron that are significant

ferric 3+
ferrous 2+

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a form of Iron that is predominant in food

Ferric 3+

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example of reducing agent that helps ferric to convert it to ferrous

vitamin C
ferric reductases (intestinal epithelium)

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Where does ferric reductases (a reducing agent) produced

intestinal epithelium

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can our own intestine or body mechanism convert ferric to ferrous?

yes

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Once the ferric is reduced into ferrous, what will happen next?

In the intestinal cell, it can be found to ferritin which is the primary function is for storage and get eliminated after sloughing off or be exported to the basolateral slide

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the primary function is for storage and get eliminated after sloughing off or be exported to the basolateral slide

bounding of iron and ferritin

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From the intestinal mucosa, iron will be ___ again to go back to ___ state and bound t0 _____ for transport throughout the body

oxidized; Ferric state; apotransferrin

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this peptide hormone regulates iron absorption in the upper gastrointestinal tract by modulating the export from cells

hepcidin

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Hepcidin, a peptide hormone, regulates iron absorption in the upper gastrointestinal tract by modulating the export of iron from cells by ____

ferroportin

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Iron can return in the circulation when the RBC was been degraded by _____ after 120 days

spleen, liver, macrophages

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Iron is lost primarily in _______

desquamation of epithelia and red cell loss in urine and feces

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With each menstrual cycle, women lose
approximately ____ mg of iron.

20-40

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health effects in increased serum iron

increased erythrocyte destruction (hemolytic anemia)
decreased blood formation (lead poisoning, pyridoxine deficiency)
increased release of iron from the body stores (release of ferritin in acute hepatic cell necrosis)
defective iron storage (pernicious anemia)
increased rate of absorption (hematochromatosis and transfusion siderosis)

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Increased in serum Iron:

conditions of increased rbc destruction such as

hemolytic anemia

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Increased in serum Iron:

conditions under decreased blood formation

lead poisoining, pyridoxine deficiency

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Increased in serum Iron:

increase release of iron from the body stores

release of ferritin in acute hepatic cell necrosis

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Increased in serum Iron: example of anemia in defective iron storage

pernicious anemia

Increased in serum Iron: conditions under increase rate of absorption

hemochromatosis and transfusion siderosis

Decreased in serum Iron:

generalized iron deficiency (lack of sufficient dietary iron) inadequate absorption of iron chronic loss of Iron as a result of bleeding or nephrosis impaired releases of iron from the reticuloendothelial system due to infection malignant rheumatoid arthritis

conditions under in Increase TIBC (total iron binding capacity)

iron deficiency late pregnancy oral contraceptives viral hepatitis

conditions under decrease in total iron binding capacity

chronic infections malignancy iron poisoning neprosis kwashiorkor thalassemia

In 3-5 mg of iron, _______ g of iron is found in the hemoglobin mostly in RBC and other red cell precursor.

2-2.5

Disorders of iron metabolism are evaluated primarily by _______

total iron content total iron binding capacity percent saturation transferin ferritin

we can measure iron metabolism by measuring the ferric iron bound to transferrin

total iron content

sample used for total iron content

serum without anticoagulant or heparinized plasma

can we use oxalate and edta in total iron content

no, it will bind with FE ions

time we must collect a sample for total iron content

early morning sample due to diurnal variation in iron concentration

we can measure iron metabolism by measuring the amount of iron that could be bound if transferrin and other minor iron binding proteins present in the serum or plasma sample were saturated

total iron binding capacity

In total iron binding capacity, Typically, only _______ of the iron-binding sites on transferrin are saturated.

one-third

we can measure iron metabolism using ____ as called as transferrin saturation

percent saturation

refers to the ratio of serum iron to TIBC

percent saturation

normal range of percent/transferrin saturation is

20% to 50% but varies with age and sex

transferrin is can be measured by immunochemical methods such as

nephelometry

relationship of transferrin to iron deficiency

increase

relationship of transferrin to chronic infections and malignancy

decrease

relationship of transferrin to iron overload and hemochromatosis

decrease

referred method for lead analysis

ICP MS

A liver biopsy sample can be digested and analyzed for iron by _____ as a follow up to abnormal blood tests consistent with an HH diagnosis

AAS and ICP-MS

can we use iron quantification in liver for evaluation of acute iron toxicity

true or false hepcidin testing has been proven to be clinically useful for iron analysis

“Quicksilver”, is a heavy, silvery metal.

mercury

Soft, bluish white, highly malleable and ductile

lead

Poor conductor of electricity & heat and resistant to corrosion

lead

Lead is widely distributed in the earth’s crust and the main lead ores are _____

galena, cerrusite, and anglesite

Lead is used in the production of ____

storage batteries, ammunition, solder, and foils

_____ was once used extensively as an additive in gasoline (petrol) for its ability to increase the fuel’s octane rating and is present in many paints manufactured before 1970.

Tetraethyl lead

The clinical presentation of lead toxicity is

variable

In children, obvious symptoms are usually seen at blood levels of ___ μg/dL or higher with 45 μg/dL as the typical threshold for acute, clinical intervention

lead exposure arises in 2 settings

childhood exposure, usually through paint chips, and adult occupational exposure in the smelting, mining, ammunitions, soldering, plumbing, ceramic glazing, and construction industries.

LEAD ANALYSIS ICP-MS is a preferred method of analysis, although ________ are also used.

ICP AES and GFAAS

Other central nervous system symptoms of lead toxicity in children may include

clumsiness, gait abnormalities, headache, behavioral changes, seizures, and severe cognitive and behavioral problems

lead tpxicity Gastrointestinal symptoms

include abdominal pain, constipation, and colic.

IQ declines are seen in children with blood lead levels (BLLs) of ___ug/dL or higher

The most common specimen type for LEAD ANALYSIS is _______, the result of which is commonly referred to as the BLL (Blood lead level)

whole venous blood

The most common specimen type for LEAD ANALYSIS is whole venous blood, the result of which is commonly referred to as the

BLL (Blood lead level)

whole venous blood This is preferred over plasma and serum as circulating lead is predominantly associated with ____

RBCs

Elevated lead levels in capillary blood specimens should be confirmed with a _______ to avoid the potential contribution of external contamination.

venous specimen

“Quicksilver”, is a heavy, silvery metal

MERCURY (Hg)

is a deadly liquid element that causes damage to the nervous system

Mercury

Along with __, mercury is one of only two elements that are liquid at room temperature and pressure.

bromine

Three (3) naturally occurring oxidation states of mercury

o Hg(0), Hg(1+), and Hg(2+).

refers to various forms of mercury bound to a carbon atom, with mercury usually in the +2 oxidation state

Organic mercury

Mercury is released to the atmosphere as a product of the natural degassing of rock (________ tons/yr)

30,000

Mercury is released to the atmosphere as a product of the natural degassing of rock (30,000 tons/yr) and through various human activities (_________ tons/yr).

20,000

Mercury is used in

dental amalgams, electronic switches, germicides, fungicides, and fluorescent light bulbs.

Very small amount of mercury coming from dental amalgams → how many pieces is considered to be acceptable; doesn’t have too much impact in our health

3 pieces

Mercury is widely used in the production of eye cosmetics, especially ____

mascara

diff route of exposure of mercury

inhalation ingestion cutaneous absorption injection dental amalgams

1. Inhalation, primarily as elemental mercury vapor but occasionally as _________

dimethyl mercury

2. Ingestion of HgCl2 and mercury-containing foods such as predatory fish species; ▪ _______ or mercury containing food / Fish species that has mercury contents

Mercury chloride

3. Cutaneous absorption of methyl mercury (MeHg) → through the skin and even through _____

latex gloves

Inhaled mercury vapor is retained in the lungs to about __%, whereas liquid metallic mercury passes through the gastrointestinal tract (GIT) largely unabsorbed

80%

Mercury enters the food chain primarily by _________ and manmade sources such as coal combustion, mining and smelting.

volcanic activity

Potent or common source of lead in the Philippines

Mining company who were mining golds from several provinces, or small mining industries that uses mercury as an amalgams to bind or para magdikit dikit yung gold

MeHg is efficiently absorbed from the gastrointestinal tract, and distribution to tissues, including the brain, appears complete in _______ hours

The __ is the major storage organ after elemental or inorganic mercury exposure.as well as methyl mercury

kidney

Mercury has no known function in normal human physiology t or f

“Quicksilver”, is a heavy, silvery metal.

mercury

Along with bromine, ___is one of only two elements that are liquid at room temperature and pressure.

mercury

refers to various forms of mercury bound to a carbon atom, with mercury usually in the +2 oxidation state

Organic mercury

used in dental amalgams, electronic switches, germicides, fungicides, and fluorescent light bulbs

Mercury

12th most abundant element in the earth’s crust

manganese

Hard, silvery white metal

molybdenum

Naturally occurring metalloid with many chemical and physical properties similar to those of sulfur.

selenium

an endemic cardiomyopathy that affects mostly children and women in childbearing age in certain areas in China, has been associated with selenium deficiency

Keshan disease

an endemic osteoarthritis that occurs during adolescent and preadolescent years, is another disease linked to low selenium status in northern China, North Korea, and eastern Siberia.

“Kashin-beck disease

Bluish-white lustrous metal that is stable in dry air and becomes cover with a white coating when exposed to moisture.

zinc

Treatment for “Wilson’s disease”

zinc

First develop a characteristic facial and diaper rash

Infants with acrodermatitis enteropathica (zinc malabsorption)