UWORLD Q Flashcards
Which type of HLA is associated with Ankylosing sondylitis?
HLA-B27
HLA Class I Serotype
What neurotransmitter is important in the development of tolerance to morphine?
Glutamate
Fluid accumilation around the testical in a 5 month old infant is indicative of this kind of hernia
Indirect Hernia–> collection of fluid within the tunica vagnialis and hydrocoele
In which part of the nephron would PAH be lowest? Why?
In Bowman’s space.
PAH is filtered and secreted. The secretion takes place in the proximal tubule. Therefore the lowest concentration of PAH woul dbe up stream of that (Bowman’s space)
Young child of European descent with fair skin, light eyes, and musty or mousy ordor. (Also may see mental status changes)
What AA becomes essential? What enzyme is implicated?
Phenylketonuria (PKU)
Lack of phenylalanine hydroxylase causes a build up of phynylalanine with a lack of conversion to tyrosine.
Tyrosine becomes essential. Leads to a lck of pigment production and catecholamine production.
Two common side effects of statin therapy, elevation of what kinase is commonly seen?
Hepatic toxicity
Myopathy–> Creatine Kinase elevation
47XXY
What does this person look like?
What is the name of the Syndrome?
Kleinfelter Syndrome
Tall, Gynecomastia, Infertile
What is the major important step in gluconeogenisis?
Oxaloacetate –> Phophoenolpyruvate
Malate–>oxaloacetate–> Phophoenolpyruvate (by phosphoenolpyruvate carboxikinase [PEPCK])
15 y/o pt. with a low fever, cough and sore throat. What is the name of the cell seen on peripheral blood smear? What kind of cell is it?
Downey cell–> infection with EBV (infectous mononucleosis)
Proliferation of atypical CD8+ T-lymphocytes
Equation for net excretion of Substance A=
Net Excretion of Substance A= (inulin clearance)(Plasma concentration of substance A) - (tubular reabsorption of substance A)
Calculation of filtration of substance A?
Filtration of A= (inulin clearence)(Plasma concentration of A)
What interleukin is release from what cell in excess in chronic asmatic bronchiolitis?
IL-5 from Th2 helper cells–> activates eosinophils
–> leads to the excess release of eosinophilic granules–> **Charcot-leyden chrystals **
Infant’s urine is brought in and had turned dark or black on the way to the office. What is the disorder? What enzyme deficiency?
Alkaptonuria
Inadequate conversion of Tyrosine to fumerate by homogentisate 1,2-deoxygenase
Leads to a build up of homogentisic acid and onchronosis (dark pigment deposistion at mucos membranes)
This image is indicative of what disease? Why?
What other signs may this patient have?
What is the mode of inheritance of this disease?
Neurofibromatosis Type 1
Multiple cafe-au-lait spots and neurofibromas. This patient may also experience arthralgias, vision changes and headaches
-Autosomal dominant single gene inheritance of NF1 gene on chromosome 17
Medication used to help diagnose asthma in a patient
Methacholine Challenge (muscarinic agonist)
Decrease of FEV1 of more than 20%
Young child with tonsilar exudates that stain with aniline dye (methylene blue)?
What is the mechanism of pathogenisis of this organsim?
Cornybacterium diptheriae
(G+ polymorphic chinese letters on microscopy)
AB toxin- B gains access and A subunit inhibits protein synthesis by binding to EF-2 of ribosomes.
Which virus type (enveloped or non-enveloped) is sensitive to the action of ether and other organic solvents? Why?
Enveloped
The envelope is derived from the host’s lipid bilayer membrane and is disrupted by the ether–> loss of infectivity
Which Gp is important for the binding of platelets to vWF and the underlying collagen?
Which Gp is involved in platelet aggregation? Which moniclonal antibody blocks this function? How?
- GpIb is responsible for initial binding of platelets to the underlying collagen. This binding activates the release of ADP(clopidigrel) and thromboxane A2 (aspirin) to activate other platelets.
- GpIIb/IIIa is responsible for platelet aggregation. Multiple IIb/IIIa receptors are cross linked by fibrinogen and this function is blocked by drugs like abciximab.
What race female has a higher bone desity at similar ages?
Black female
A defect in debranching enzyme presents how?
What is the name for this disorder?
What is the normal function of the enzyme defect?
Cori disease (debranching enzyme defect) presents with:
–> hepatomegaly, hypoglycemia, hypertiglyceridemia, and ketoacidosis.
Debranching enzyme–> normally cleaves the last 3 or 4 glycogen at their alpha 1-4 linkages and moves them to the main chain. Then the alpha-1,6-glucosidase cleaves the last glycogen to liberate glucose.
McArdel’s Disease
Deficiency of Glycogen Phosphorylase in muscle (McArdel’s=Muscle)
–> increased glycogen in the muscles with no breakdown leading to painful muscle cramps and myoglobinuria with exercise
Pompe’s Disease
Deficiency of lysosomal alpha-1,4-glocosidase (normally cleaves glycogen A-1,4-glycocidic bonds)
–> Leads to a buildup of glycogen in all tissues but notably the heart leading to cadiomegaly.
(Pompe= buildup in the Pump)
Von-Gierke’s disease
Lack of Glucose-6-phosphatase dosen’t allow of liberation of glucose after the final step of glycogenolysis or gluconeogenisis.
Results in: severe fasting hypoglycemia, Marked increase in liver glycogen, increased blood lactate and hepatomegaly.
What antibody is present in high amounts and is very specific for RA?
Anti-cyclic citrullinated peptide antibodies (Anti-CCP)
What enzyme is present in herpes and varicella virus and is not in CMV and EBV and contributes to the effectiveness of drugs like acyclovir (guanisine analogue)?
Thymidine Kinase
–> present in HSV and VZV–> phosphorylates and activates acyclovir
CMV and EBV do not have this enzyme and therefore can not effectively activate acyclovir
Most effective treatment to raise HDL?
Naicin
Persistent vitelline duct is associated with what other developmental abnormality?
Meckel Diverticulum
What B blocker also has K+ channel activity and can prolong the QT interval?
Sotalol
Patient drinks a lot of alcohol then has palpitations. What is the abnormality and what is seen on EKG?
Atrial Fibrillation
Absent P waves
Clozapine should be followed with what test? Why?
CBC
Induces granulocytopenia
From what AA does NO come from?
Arginine
What are the two locations of ribosomes? Where do their respective products act?
Free ribosomes: synthesize cytosolic proteins
RER or Membrane bound ribosomes: Synthesize secretory, membrane bound, and lysosomal proteins.
Rh antibodies are what kind of Ig?
IgG
K+ sparring diuretics act in what part of the nephron?
Collecting duct
Patient with sarcoidosis, what cell is elevated in bronchiolar levage fluid?
CD4+ Lymphocytes
Glycerol is acted upon by what enzyme that is only present in the liver in the process of triglyceride breakdown?
Glycerol is acted upon by glycerol kinase–>glycerol-3-phosphate–>DHAP which then enters glycolysis
Cystic fibrosis is a defect in what kind of transporter?
CFTR–> ATP-binding casset Cl- transporter
Fenoldepam is used in what situation? What is its MOA?
It is a benzopine that is used in the Tx of hypertenisive crisis.
D1 receptor agonist that preferentially increases cAMP in renal, mesenteric and coronary beds–> vasodilation
A lesion in the right temporal lobe would result in what visual deficit?
“Pie in the sky” Left hononomys superior quadrantanopia
Due to compression of the upper portion of the optic radiation.
What is a serious complication of treatment of a trauma patient with mannitol?
The volume expansion from fluid being pulled from the ECF lead to an increase in vascular hydrostatic pressure and can lead to serious pulmonary edema.
Terbinafine acts as an antifungal by….
How do the -azoles act?
Inhibitbing squalene epoxidase
UAA, UAG and UGA all will cause the binding of….
Release factors
They are all stop codons
(U Are Away, U Are Gone, U Go Away)
Scare tissue after MI is composed promarily of what type of collagen and therefore will resemble what structures?
Type I collagen
-bone, skin, tendon
Paitent who presents with poilio most likely got the infection by what route?
Fecal oral
-Enterovirus: RNA vireus so nammed due to its fecal-oral transmission (aslso includes coxsackie virus and echovirus)
Esophageal varicies in cirrhosis are caused by portal-caval anastomosis between what two vein?
How about hemorrhoids and caput medusa?
- Esophageal varicies: Left gastric and Esophageal V.
- Hemorrhoids: superior rectal v. and middle and inferior rectal
Caput medusa: para-umbilical V. and Superior/Inferior epigastric
What is the function of Kinesin?
To carry vessicles away from the nucleus
e.g. Anterograde transport of NT in a neuron
Which antibiotic used to treat MRSA causes elevation of CPK and myopathy?
What is it’s MOA?
Daptomycin
MOA: Depolarization of pathogen membrane
What is the MOA of Vancomycin?
What is the most severe adverse side effect?
Inhibits polymerazation of murine monomers by binding to D-Ala-D-Ala and inhibiting glycoprotein syntheisis
–>nephrotoxicity
What types of drug are the choice in treating alcohold withdrawl symptoms?
Benzodiazepines
What drug will decrease the uptake of radioactive iodine? How?
Perchlorates
–>they compete for the N+/I- symporter
Characteristics of anaplastic cells:
- Loss of polarity
- Variation in size and shape
- Dysproportionately large nuclei
- Multinucleated giant cells
Most sensitive hormone test in menopause? Why?
FSH
–> FSH increases early in pregnancy due to the loss of estrogen negative feedback
What is the effect of estrogen on thyroid values and function?
Estrogen prevents the breakdown of thyroid binding globulin (TBG) and therefore causes an increase in bound and total T4 levels.
–>Free T4 and T3 levels remain normal and so the patient remains euthyroid and has a noral TSH.
Which interleukin allows for Ig class switching after presentation of an antigen? How?
IL-4
–> IL-4 activates TH2 cells and stimulates B-cells to class switch into plasma cells and produce IgG, IgM, and IgE to the offending antigen.
Deficiency of dihydropterin reductase causes a disease known as ______ ______.
What is the result of this deficiency?
-malignant or atypical phenylketonuria
–> BH2 can not be reduced back to BH4–> this results in decreased production of dopamine and therefore elevated levels of serum prolactin.
Factor contributing most to increased bone mass in a female?
Genetic factors
Most common cause of osteomyelitis in chidhood?
Sickel cell?
Pott disease?
Children- S. aureus
Sickel cell- Salmonella
Pott disease- TB
What is the most common laboratory abnormality seen in Legionella pneumophilia pneuomonia?
What are some other common Sx?
How about the etiology?
Etiology: Person who was on a cruise or trip to watery place (hotel)
Hyponatremia is a characteritic finding in L. pneumophilia
-High fever (>39c), watery diarrhea, pulmonary consolidation
Potter sequence/syndrome cause and Sx:
Oligohydramnios/Anhydramnios due to renal aplasia or agenisis
–> Club feet, nasal occular ear and jaw deformities and pulmonary hypoplasia.
What supplement can reduce the rate of stomatitis in methotrexate therapy?
Folic acid
What baseline test should be acquired before beginning statin therapy? When should this value be obtained again?
LFT
–>Should be tested again if the pt is experiencing anorexia, fever or malaise.
The metanephric bastema gives rise to what part of the kidney?
Bowman’s space, PCT, DCT, and collecting ducts.
Tetanus vaccine allows the body to produce antibodies that do what?
Bind to inactivate the tetanus toxin
What virus commonly causes aseptic meningitis in children?
Echovirus
Filtration fraction (FF)=
FF=(GFR/RPF)
Renal Plasma Flow (RPF)=
RPF= (1-HCT)(RBF)
What are the effects of the toxins associated with C. difficile?
A toxin: Chemoattractant for neutrophils resulting in mucosal swelling and diarrhea
B toxin: causes actin depolymerazation–> leading to loss of cytoskeleton integrity, and cell death and necrosis of mucosa
What is the most common cause of retinitis in AIDS pts?
What is it treated with?
What CD4+ Tcell count is associated with this infection?
CMV retinitis
Gancyclovir
CD4 count <50
Mnenomic to remember the Class I antiarrythmics:
Double Quater Pounder. Lettuce Tomato Mayo. More Fries Please.
Where are thyroid hormone receptors located?
Within the nucleus
How is the attributeable risk calculated? What is it?
ATR= (Relitive risk (RR)- 1) / (RR)
It is the risk attributable to a certain exposure
What MHC class is only presented by antigen presenting cells?
MHC Class II
What is a side effect of antipschotic use that can be relieved by M1 agonists? How does this reaction come about?
Acute dystonia and EPS
–> caused by D2 receptor blockade in the nigrostriatal pathway that leads to muscle spasm (torticollis) and parkinson like muscle tremors.
Occurs most frequently with stonger antipsychotics like haloperidol and fluphenezine
Wide, fixed splitting of S2 is indicative of what disorder? This can cause irreversible injury to what structure?
ASD
Pulmonary vessels
ARBs bind to this receptor:
AT-1 receptor
Leads to: increase renin, increased AT1 increased AT2 and decreased aldosterone
Patients with polycystic kidney disease are at risk for what kind of aneurysm?
Berry aneurysm
Tx with what class of drug has been shown to decrease mortality after a subarachnoid hemorrhage (SAH) d/t aneurysm rupture?
Calcium channel blockers
–> Neurologic deficits in a patient soon after SAH and PCKD
Aggregates of packed follicles in a patient with painless lymphadenopathy.
What disease, What mutation and gene product?
Follicular lymphoma
t(14;18)
BCL-2 overexpression
Which of the following viruses are acid stable? Explain.
- Coxsackie A
- Poliovirus
- Echovirus
- Rhinovirus
- Hepatitis A
- Rhinovirus
–> Polio, echo and coxsackie are all enterovirusis, all names so because they are stable in the GI tract
–> This is why rhino virus is respiratory
What two markers may appear in the amniotic fluid of a fetus with an NTD?
- alpha-fetoprotein
- acetylcholinesterase
–>both due to incomplete fusion of the neural tube
What drug can be givin IM during accute hypoglycemia?
Glucagon
Why does anemia of a patient with M. pneumonia resolve spontaneously after Tx?
Cold Agglutinins (Ab against RBCs) are what cause the anemia.
Once the infection is treated, the anemia will resolve.
Patient with joint pain and hard nodules at the pip joints?
Osteoarthritis
Bouchards and Haberdens nodes
B before H
RNA primer is removed by which enzyme?
DNA polymerase I
Trisomy 21 is at long term risk for what hematologic disorder?
ALL
(acute lymphoblastic leukemia)
Does cushing syndrome result in hyperplasia or hypertrophy of the zona faciculata and reticularis?
Hyperplasia
What structure lies just anterior to the esophagus and can be visualized on ultrasoundography?
Left atrium
What is the most common cause of torticollis?
Intrauterine malpositioning
What section of the nephron is impermeable to H20?
The ascending loop and the early distal convoluted tubule
What is the most common site of MRSA in a colonized individual?
Anterior Nare
Methicillin resistance arises from…..?
Mutations resulting in poor binding of drugs to penicillin binding proteins (PBP)
What is a buzzword sign of arsenic insectiside poisoning? How is it treated?
Garlic smell on breath
–>Tx with dimercaperol
Methimazole major MOA?
Inhibition of iodine peroxidase therefore organification and coupling of iodine.
What is a major side effect of amiordarone therapy? Blood studies for this shoul dbe conducted before starting amiodarone.
Thyroid dysfunction
Amiodarone is 40% iodine by weight!!!!
Ballooning and vacuolar degeneration with oxylate chrystals in the kidneys.
Ethylene glycol poisoning
To what part of the tRNA does the amino acid bind?
to the 3’/5’ acceptor end (the free end)
In fertility therapy, hCG is given to induce production of what other hormone?
LH surge
Trisomy 18 is associated with what musculoskeletal abnormalities?
How about GI?
Clenched hands
Over-riding pointer and pinky finger
Rocker-bottom feet
–> Meckel diverticulum
PSGN results is brought about by what mechanism? How does it appear on microscopy?
Immune complex deposition (antigens produced against the pathogen cross react with host glomerular basement membranes)
–> Lumpy-bumpy appearence
Para-aminobenzoic acid (PABA) protect against what form of radiation?
UVB only!
Clotting factors affected by warfarin…GO!
II, VII, IX and X
Protein C and S
What kind of antidepressants have a greater risk of inducing mania?
TCAs and venlafaxine
If immunoglobulins can not class switch, what class is default?
What are the signs and symtoms?
Hyper IgM syndrome–> IgM is the first in the translated region
–>recurrent mucosal infections due to lack of IgA
t(14;18) results in overexpression of this gene product
Bcl2
What are two short acting benzodiazepines?
Tirazolam and alprazolam
Increased MCV, anemia, poikoilocyes, and hypchromia in a mediterannian male?
B-thalassemia
Dysfunctional mRNA processing
Young male with fatigue, polydipsia, and polyuria. Unablt to gain weight.
Type I diabetes mellitus
Which myeloproliferative disorders are associated with a JAK-STAT mutation?
Primary myelofibrosis
Polycythemia vera
Essential thrombocytosis
Drug of choice for trigeminal neuralgia
Carbamazepine