Vitamin B 12 #2
decreased serum cortisol
Addison Disease
-Intrinsic factor deficiency -surgical removal of terminal ileum -intrinstic dz of terminal ileum (chrons, celiac, lake fish tapeworms, bacteria) -meds
impaired absorption of vitamin b 12
-characteristics of PA -inflammation of lymphocytes within the gastric walls -degeneration of parietal cells and replacement with globlet cells what is this phenomenon called?
intestinal metaplasia
principal abnormailty in perncious anemia is the absence of _____ _____
intrinsic factor
what skin color can patients present with?
lemon yellow skin color
low wbc
leukopenia
following the megaoblasts release into the circulation they are then known as
macrocytes
why is the MCV high
macrocytic anemia
-positive family history of perncious anemia -Scandinaviean or Celtic descent -medical history of an autoimmune disease (type 1 dm, graves, hasimotos, addisons)
major risk factors of vitamin b 12 deficiency
abnormal development of RBC results in premature cell death and phagocytosis within the bone marrow. this is known as
megaloblastic anemia
in the bone marrow these large immature RBC are known as
megaloblasts
a deficiency of vitamin b 12 causes abnormal methylation of the protein compound of myelin and causes the synthesis of abnormal myelin. this results in myelin degeneration and produces _____ _____
neurological complications
when the vitamin is deficient what occurs?
nuclear maturation and cell division of rapidly proliferating RBC fail to occur within the bone marrow (megaloblastic anemia)
despite DNA synthesis in developing RBC of people who are b 12 deficient RNA process occurs at a normal rate which results in disparity between ____ and ____
nucleus and cytoplasm
bone marrow biopsy will show
RBC hyper cellularity megaloblasts
demylenation of the peripheral nerves causes what in the hands and feet?
paraesthesia
abnormal condition characterized by an elaborate, suspicious system of thinking that is usually centered on one major theme such as an unfaithful spouse, being poisoned, or being watched by outer space aliens
paranoid
-macrocytosis -ansiocytosis -polikocytosis -hypersegmented neutrophils -giant platelets -normal lymph and plasma where will this be found?
peripheral blood smear
most common cause of vitamin b 12 deficiency anemia is known as____ ____
pernicious anemia
-surgical removal of stomach -chronic gastritis -use of PPT -chronic pancreatic dz
poor utilization/seperation
why is it reasonable to test the serum folic acid concentration in a patient who is suspected of having it b 12 deficiency
present with similar lab findings need to differentiate
what is alchlorhydira?
production of hydrochloric acid in gastric secretions is low in the stomach
the effectiveness of B12 replacement is measured by an increasing ____ count
reticulocyte count
______/______ descents are at a higher risk of developing vitamin b 12 deficiency
scandiavians/celtics
-poor sensory vibration -positive babinski -impaired senses -subnormal deep tendon reflexs what does this indicate?
spinal cord demylenation
-anorexia with weight loss -burning or soreness of the tongue -nausea and vomiting -paraestheisa -symptoms that mimic Alzheimer's Dz -delusions, hallucinations, paranoias -spinal cord damage that can result in abdominal ridgity and severe pain, urinary retention, uncoordinated movements
symptoms of vitamin b 12
where is vitamin b 12 absorbed? where is it stored?
terminal ileum liver
low platelets
thrombocytopenia
vitamin b12 promotes synthesis of (3)
thymindine synthase function DNA synthesis normal development on nucleus in cells
need to obtain family history because genetically transmitted deficiencies of ______ occur in families as an auto recessive gene
transcobalamin II
lack of serum insulin
type 1 DM
vitamin b 12 deficency is commonly seen in
vegetarians, alcoholics
demyelination of the spinal cord results in loss of ____ senses in the arms and legs and eventually ataxia.
vibratory
-fatigue -weakness -lightheadedness are common symptoms of
vitamin b 12 deficency
-abnormally large -flimsy cell membranes -oval shape -highly succeptible to intramedullary hemolysis characteristics of
vitamin b 12 deficency RBC
-sore tongue -poor appetite -diarrhea
vitamin b 12 deficency compliants
-lemon waxy looking skin -yellowing of the eyes -premature grey hair -low grade fever -red smooth beefy tongue -dyspnea -tachycardia -retinal hemmorages -hepatomeagly -splenomeagly -pedal edema
vitamin b 12 deficency symptoms
how do you treat vitamin b 12 deficiency?
vitamin b 12 replacement
are peripheral nerves usually affected first? what does the patient complain of?
YES, paraesthia in hands and feet
congenital enzyme defects that result in impaired deoxyadenosylcobalamine or methylcoblamin synthesis
abnomrla utilization of vitamin b 12
congenital deficiency of plasma protein carrier transcobalamin II will lead to
abnormal plasma transport of vitamin b 12
signs of pedal edema indicate
anemia is severe and HF has developed
reticulocytes are low, what type of anemia?
aplastic
why is the systolic border best heard at the right sternal border?
bc hematocrit is less than 20%
why is achyloridia reasonable to find in patients with pernicious anemia?
because there is a commonly problems with the stomach lining in patients because of improper neutrition and alcohol
the posterior columns of the spinal cord degenerate when the deficency becomes more severe. what happens as a result?
cerebral function is altered can cause dementia and depression
what meds can cause impaired absorption of vitamin b 12?
cholestyramine neomyocin metformin phenoformin colchine
why is there a mild loss of mental status?
damage to the myelin sheath
persistant aberrant beliefs or perceptions held inviolable by a person despite evidence that refutes them
delusions
-strict vegetarian diet -chronic alcoholism what type?
dietary insufficiency of b12
use of ___ ___ ___ ___ can lead to decreased b 12 levels, may play a role in vitamin b 12 deficiency
gastric acid blocking agents
increased serum thyroxine
graves disease
abnormal sensory perceptions that can occur in any of the senses, do not result from an external stimulus and occur in the walking state
hallucinations
decrease serum thyroxine
hasimotos thyroiditis
severe anemia may present with
heart failure and retinal hemorrhages
elevated serum biliruben indicates
hemolysis of RBC
as a result of significant degree of cell death that occurs from vitamin b 12 deficiency, serum LDH levels are ____
high
As methylcobalamin, the vitamin serves as a co factor for methionine syntheses in conversion of ______ to _____
homocysteine to methionine
what are reticulocytes?
immature blood cell without a nucleus
if a patient has pernicious anemia, what will the gastric evaluation present?
-absence of hydrochloric acid -lymphocytes in the walls of the stomach
vitamin b 12 caused by 5 things
-inadequate intake -impaired absorption -impaired plasma transport -poor utilization/serperation
what is vitamin b 12 essential for?
-RBC production -nervous system conduction -DNA synthesis
If the father of an unborn child has a single defective gene/mutation for transcobalamin II deficiency and the mother has two normal genes, what is the probability that their unborn child will be transcobalamin II deficient?
0%
If both the father and mother of an unborn child each have a single defective gene/mutation for transcobalamin II deficiency, what is the proba- bility that their unborn child will be transcobalamin II deficient
25%
how many plasma proteins transport b 12?
3
human body stores how many years of vitamin b 12? what does this cause?
3-5 years worth signs of deficiency will occur slowly in adults and quicker in children because they have less storage
nervous system conditions are reversible with B 12 replacement only if the treatment occurs within ___ months of onset
6
which transcobalamin is capable of transporting vitamin b 12 into cells for use?
II
if megaloblastic anemia results from the lack of dietary intake the condition may be initially treated with _____ injections and then maintained with oral b 12
IM
what is a specific test for vitamin b 12? will it be high or low with vitamin b 12 deficiency?
MMA (methylmanoic acid) HIGH
serum antibodies to parietal cells and serum antibodies to intrinsic factor POSITIVE indicative of what?
PERNCIOUS ANEMIA
Trascobalamins I and II are secreted by
WBC