Day 4 June 24 Flashcards
Is asthma mediated by a Th1 or Th2 response?
Th2
Role of Th1 response?
Cell mediated adaptive immunity (targeting intracellular pathogens)
-type IV sensitivity reactions
Is a th1 or th2 response implicated in a type IV hypersensitivity reaction?
Th1
What is the function of IL5?
recruits eosinophils
which two cytokines are secreted by Th2 cells to stimulate B cell class switching to igE (in asthma)?
IL4 and IL13
anticentromere antibodies are found in which conditions?
CREST Calcinosis Raynauds Esophageal dysmotility Sclerodactyly Telangiectasias
Which autoantibodies is SPECIFIC for rheumatoid arthritis?
anti-cyclic citrullinated peptide (anti-ccp)
why are anti-cyclic citrullinated protein antibodies found in RA?
tissue inflammation leads to arginine residues in proteins to be converted to cirtulline, this alters the shape and can generate an immune response
Phosphatidylcholine AKA
lecithin
how does the Phosphatidylcholine : sphinomyelin ratio change throughout pregnancy?
The ratio is about equal until the middle of the third trimester, when phosphatidylcholine increases sharply as type II pneumocytes have begun secreting surfactant
What lecithin to sphinomyelin ratio indicates adequate surfactant production to prevent hyaline membrane disease in the neonate?
2:1
Most common lead point for intussusception?
ileocolic junction -difference in sizes allows to small bowel to go into large bowel
Clinical presentation of intussusception?
colicky pain, nausea, vomiting and currant jelly stools
what type of hormone is ADH?
peptide
what type of hormone is prolactin?
peptide
what vitamin is essential for NAD and NADP?
B3 (nicotinic acid)
what causes niacin deficiency in developing countries? in developed countries?
Corn diet
Poor nutrition
niacin may be synthesized from ___
tryptophan
Serotonin may be synthesized from ___
tryptophan
tyrosine can be synthesized from ___
phenylalanine
DOPA, dopamine, NE and epinephrine are synthesized from….
tyrosine (which comes from phenylalanine)
Presentation of inhalant abuse?
transient euphoria, lethargy, disorientation, LOC, poor coordination, slurred speech - short duration of effects-rapid recovery
-‘glue sniffers rash’ - dermatitis around mouth or nose
what mutation is commonly found in patients with familial dilated cardiomyopathy?
TTN -a truncating mutation of titin - the protein that anchors myosin heavy chains to Z discs in the sarcomere
inheritance of TTN mutation?
autosomal dominant, with incomplete penetrance - meanign it may show up later in life or not at all
presentation of dilated cardiomyopathy
symptoms of decompensated heart failure possibly resulting in sudden cardiac death from arrhythmia
which genes are commonly mutated in patients with hypertrophic cardiomyopathy?
Beta myosin heavy chain or myosin binding protein C mutations
a mid shaft humeral fracture may damage which structures?
radial nerve -loss of extension of hand/elbow and loss of supination
deep brachial artery
acyclovir MOA
guanosine analog - HSV phosphorylates it into its active form which them impairs DNA polymerase mediated replication
why is acyclovir not as active in EMV or CMV?
these virus’s dont have the same thymidine kinase as HSV and thus do not phosphorylate the drug into its active form
how may body composition change after taking highly-active antiretroviral therapy (HAART)?
Lipoatrophy in the face, extremities and buttocks with central fat deposition causes increased abdominal girth and buffalo hump
MOA of thiazolidinediones?
bind to and activate PPAR gamma
PPAR gamma MOA
upregulates genes resulting in increased GLUT4 ->
- increased glucose uptake in adipose and skeletal muscle in response to insulin
- increased adiponectin - sensitives adipose cells to insulin and stimulates FFA oxidation
what drugs can cause methemoglobinemia?
- Dapsone
- Nitrites/nitrates
- Local/topical anesthetics (benzocaine, teething medications)
Presentation of methemoglobinemia?
Cyanosis
Chocolate-brown blood
Innacurate pulse oximetry
Management of methemoglobinemia
Meythlyne blue -reduces iron back to Fe2+
In which layer are parietal cells found?
The upper glandular layer
In which layer are cheif and delta cells found?
deep gastric glands
how does vagal stimulation increase H release int he stomach?
Causes Ach secretion, which binds to M3, which activates Gq -> IP3 and increased Ca, activates H/K pump
How does gastrin increase H release in the stomach?
Binds to CCKb receptor ->activates Gq -> increasd IP3 and Ca -> activation of H/K pump
how does histamine increase H release in the stomach?
binds to H2 receptor -> activates Gs -> increase cAMP -> activation of H/K pump
how do prostaglandins and somatostatin decrease H secretion in the stomach?
bind to their receptors and activate Gi -> decreased cAMP -> decreased H/K activity
how does mitochondrial myopathy present?
Brain and muscle effected first due to high metabolic demand - > muscle weakness, myalgia, lactic acidosis, nervous system dysfuction (seizures, neuropathy)
what will be seen on muscle biopsy of someone with mitochondrial myopathy?
ragged red fibers
medication induced esophagitis is associated with which type of drug?
bisphosphonates
bisphosphonates MOA?
inhibits osteoclasts
osteonecrosis of the jaw is associated with what drugs?
bisphosphonates
how are monoclonal antibodies eliminated?
- Target mediated drug clearance- internalized via receptor mediated endocytosis
- Non specific clearance: taking up by reticuloendothelial cells and vascular endothelial cells
are monoclonal antibodies eliminated in the liver or kidney?
NOOOOOOOO
how does impaired beta oxidation present?
hypoketotic hypoglycemia -presents after a significant fast leading to hypoglycemia, hepatomegaly, and liver dysfunction
what does a deficiency of acyl - coa synthase cause?
primary carnitine deficiency (this is a deficiency of transporting LCFAs into the mitochondria, leading to toxic accumulation)
name two disorders of beta oxidation
MCAD deficiency
Primary carnitine deficiency
what is MCAD caused by?
deficiency in medium chain acyl-coA dehydrogenase - > cant break down fatty acids into acetyl-coa
presentation of MCAD deficiency?
Hypoketotic hypoglycemia, seizures, vomiting, lethargy, coma, liver dysfunction, hyperammonia, can cause sudden death in infants and children
how to treat disorders of beta oxidation?
avoid fasting
explain the membrane physiology of pacemaker cells (nodal cardiac cells)
Theres only phase 0, 3 and 4
0: upstroke - L type Ca channels open at -40, leading to Ca influx
3: repolarization - closure of L type Ca channels, and efflux of K channels
4: pacemaker potential - slow influx of Na, with slow decrease of K efflux. When the membrane gets to -50, T type Ca channels open, then at -40, L type open -> depolarization
Which phase of the cadiac nodal action potential does adenosine and acetylcholine effect?
Phase 4
Effects of adenosine on phase 4 of the myocardial action potential in nodal cells (MOA)
- increase the efflux of K by binding A1 receptors and inhibits L-type Ca channels decrease influx
- this results in the cell staying negative and increases the time between depolarizations - slowed sinus rate
Cardiac use of adenosine
terminating paroxysmal supraventricular tachycardia
which nerve originates from the musculocutaneous nerve?
the lateral cutaneous nerve of the forearm - sensory to lateral forearm
pathophys of post strep glomerulonephritis
immune complex deposition along the basement membrane of the glomerulus (deposits of igG, igM, and c3
is post strep glomerulonephritis a nephritic or nephrotic syndrome?
nephRITIC
what does post strep glomerulonephritis look like on electron microscopy?
dome shaped subepithelial humps
LUMPY BUMPY
Fibrin deposition is characteristic of which nephritic syndrome?
rapidly progressive (crescenteric) glomerulonephritis
why is dextrose useful for treating an attack of AIP?
IV dextrose = carb loading
and glucose inhibits ALA synthase
how does carbamazepine?
inhibits Na channels preventing recovery from inactivation -decreased nerve firing rate
