Sun Jul 12 Flashcards
how do cystine kidney stones appear on microscopy?
hexagonal
patients with cysteinuria are unable to absorb which 4 amino acids?
COLA cysteine ornithine lysine arginine
what is the MOA of sulfamethoxazole?
Structural analog of PABA which competes with PABA and inhibits dihydropteroate synthetase - enzyme needed for dihydrofolic acid synthesis
what is sulfamethoxazole an analogue of?
PABA
what enzyme does sulfamethoxazole inhibit?
dihydropteroate synthetase
which enzyme does methotrexate, trimethoprime, and pyrimethamine inhibit?
dihydrofolate reductase
function of dihydrofolate reductase?
converts dihydrofolic acid into tetrahydrofolic acid
MOA of NRTI’s?
they get incorporated into DNA, but since they have a missing 3’hydroxyl group, 3’5’ phosphodiester bond formation cannot occur and instead there is chain termination
what is tenofavir?
an NRTI
how may tenofavir result in acute kidney injury?
it is eliminated by the PCT in the kidenys, and high concentration may interfere with mitochondrial DNA synthesis leading to cellular toxicity
at which pH does uric acid precipiate?
acidic pHs
where is the lowest pH in the nephrons?
the DCTs and collecting ducts
how can you prevent tumour lysis syndrome?
urine alkalinization (to prevent uric acid precipitation), aggressive hydration, and allopurinol (to reduce uric acid production)
where are the pretectal and edinger-westphal nuclei found?
upper midbrain
where is ghrelin produced?
the gastric pits of the stomach
which enzyme is deficient in AIP ?
PBG deaminase
which enzyme is deficient in porphyria cutanea tarda?
uroporphyrinogen decarboxylase
abciximab MOA?
GPIIb/IIIa receptor antagonist- thus blocks GPII/IIIa from binding to fibrinogen and forming a platelet plug
clopidogrel MOA?
blocks platelet aggregation via blocking P2Y12 on platelet ADP receptors
which type of diuretic increases Ca reabsorption?
thiazides
pathophys of ankylosing spondylitis?
increased osteoclast activity leads to bone erosions, with new bone formation occuring primarily at the periosteal margin and cartilage, leading to bridging syndesmophytes and ankylosis
do gastric ulcers require biopsy?
yes as they may be malignant
do duodenal ulcers require biopsy?
no -they are very rarely malignant
presentation of fibromyalgia?
widespread musculoskeletal pain fatigue impaired attention and concentration psych disturbances(depression/anxiety) multiple tender points
> 3 months
does polymyalgia rheumatica have tender points of psych symptoms?
NOOOOO
presentation of classic dengue fever?
- flulike febrile illness with myalgias and joint pain (break bone fever)
- retro-orbital pain
- rash
presentation of dengue hemorrhagic fever?
increased vascular permeability
- thrombocytopenia
- spontaneous bleeding
- positive tourniquet test (petechia after sphygomomanometer cut inflation for 5 min)
how is dengue fever spread?
aedes mosquito
what type of virus is dengue fever?
ss RNA
Flavivirus
the superior laryngeal nerve is part of which Cranial nerve?
CN X
what is the function of the superior laryngeal nerve?
sensory - mediates affarent limb of cough reflex - carries sensation from the mucosa to the vocal cords
which nerve runs superficially through the piriform recesS?
the internal laryngeal nerve (a branch of the superior laryngeal nervE)
what mediates the affarent and efferent limbs of the gag reflex?
CN IX and X respectively
presentation of graft vs host disease?
any organ can be targeted but it commonly involves the skin, liver and GI tract
- may present as maculopapular rash that goes to the palms and soles
- abnormal LFTs
- diarrhea, abdominal pain and GI bleeding
what are the embryological deritivates of the neural tube?
- Ne
- Astrocytes
- Spinal cord
- Pineal gland
- Oligodendrocytes
- Retina
- Ependymal cells
- Neurohypophysis
what does the brain and spinal cord derive from?
neural tube
what does the posterior pituitary and pineal gland derive from?
neural tube
what does the retina derive from?
neural tube
what are the embryological deritivates of the neural crest?
- Schwann cells
- PNS
- Adrenal medulla
- Myenteric plexus
- Spiral membrane
- Melanocytes
- Odontoblasts
- Thyroid C-cells
- Endocardial cushion
- Laryngeal cartilage
which bones are derived from the neural crest?
skull bones
which layers of the meninges are derived from the neural crest?
pia and arachnoid
what are the embryological deritivates of the surface ectoderm?
anterior pituitary (rathkes pouch) lens and cornea inner ear sensory organs olfactory epithelium salivery glands epidermis, sweat and mammary glands
where do the mammary glands derive from?
surface ectoderm
what does rathkes pouch derive from?
surface ectoderm
where do melanocytes derive from?
neural crest
where do the salivary glands derive from?
surface ectoderm
how many calories are produced by 1 gram of fat?
9
how many calories are produced by 1 gram of protein?
4
what is the function of the lateral pterygoids?
Opening the jaw
adverse effects of clozapine?
Agranulocytosis
Seizures
Metabolic syndrome
Myocarditis
gram stain of nocardia?
filamentous, branching, gram + rods
Partially acid fast
treatment of nocardia?
TMT-SMX
presentation of rocky mountain spotted fever?
Begins with fever, headache, myalgias, and malaise, followed 3-5 days later with a macular rash that moves from the extremities inwards
what causes rocky mountain spotted fever?
rickettsia rickettsia
treatment of rocky mountain spotted fever?
doxycycline
what is the half life of naloxone?
<1 hr - short half-life (this means patients who overdosed may need repeated dosings)
how will diastolic blood pressure be effected during aerobic exercise?
There is vasoconstriction of splanchnic arterioles but larger amounts of vasodilation of arterioles in the muscles, during aerobic exercise, leading to an overall decreased SVR. However the increased venous return and stroke volume of the heart during aerobic exercise offsets this, leading to an overall unchanged or slightly decreased diastolic pressure
how will systolic blood pressure be effected during aerobic exercise?
It will be increased– due to increased venous return to the heart and increased contractility resulting in greater stroke volume
MOA of ethosuximide
Blocks thalamic T-type Ca channels
what neurotransmitter is produced by the nucleus of Meynert?
Ach