LEC10 - TRACE ELEMENTS - Iron-Zinc Flashcards
4th most abundant element in the earth’s crust
iron - FE
most abundant transition metal
iron
iron participates in the following:
oxygen transport
redox chemistry in both ferrous and ferric states
agent in redox and electron transfer reactions
do FE has magnetic properties?
yes - that is why it is an element added to make steel
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.
about how many percent of iron are absorbed in dietary per day
10% of the approx 10-20 mg/day of dietary iron
how intestinal cells absorbed iron
iron must be in ferrous 2+ oxidation state and bound to protein
2 forms of iron that are significant
ferric 3+
ferrous 2+
a form of Iron that is predominant in food
Ferric 3+
example of reducing agent that helps ferric to convert it to ferrous
vitamin C
ferric reductases (intestinal epithelium)
Where does ferric reductases (a reducing agent) produced
intestinal epithelium
can our own intestine or body mechanism convert ferric to ferrous?
yes
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
the primary function is for storage and get eliminated after sloughing off or be exported to the basolateral slide
bounding of iron and ferritin
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
this peptide hormone regulates iron absorption in the upper gastrointestinal tract by modulating the export from cells
hepcidin
Hepcidin, a peptide hormone, regulates iron absorption in the upper gastrointestinal tract by modulating the export of iron from cells by ____
ferroportin
Iron can return in the circulation when the RBC was been degraded by _____ after 120 days
spleen, liver, macrophages
Iron is lost primarily in _______
desquamation of epithelia and red cell loss in urine and feces
With each menstrual cycle, women lose
approximately ____ mg of iron.
20-40
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)
Increased in serum Iron:
conditions of increased rbc destruction such as
hemolytic anemia
Increased in serum Iron:
conditions under decreased blood formation
lead poisoining, pyridoxine deficiency
Increased in serum Iron:
increase release of iron from the body stores
release of ferritin in acute hepatic cell necrosis
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
no
true or false
hepcidin testing has been proven to be clinically useful for iron analysis
no
“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
60
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
10
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
- Inhalation, primarily as elemental mercury vapor
but occasionally as _________
dimethyl mercury
- Ingestion of HgCl2 and mercury-containing foods
such as predatory fish species;
▪ _______ or mercury containing food /
Fish species that has mercury contents
Mercury chloride
- 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
48
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
t
“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)
