Miscellaneous Flashcards
What are the start and stop codons for protein synthesis?
Start: AUG
Stop: UAA, UAG, UGA
Which histones make up the nucleosome core?
8 histone proteins (2 molecules of each H2A, H2B, H3, and H4)
H1 is outside the histone care and helps package nucleosomes into more compact structures by binding and linking the DNA between adjacent nucleosomes.
Blinding in a clinical study prevents what type of bias?
Observer bias.
Prevents patient or researcher expectancy from interfering with an outcome.
Osteocytes are connected to eachother due to what cellular structure?
Gap Junctions
H. pylori antral gastritis is associated with the formation of what?
DUODENAL ulcers.
unchecked gastrin production due to destruction of somatostatin-secreting cells in the gastric antrum
Adenomatous polyps are premalignant to colon cancer. What enzyme activity has been found to be increased in colon adenocarcinoma? what medication can be used as a preventative?
COX-2 increased
prophylactic aspirin
young Pt (age 3-10) presents with marfanoid habitus, ectopia lentis, and developmental delay at increased risk of experiencing thromboembolism. What disease are you thinking? How can you treat it?
Homocystinuria caused by cystathionine synthase deficiency
treat with pyridoxine (vitamin B6) which is a cofactor for cysteine synthesis. Also diet restriction of methionine
What is the unit of analysis in ecological studies vs something like cross-sectional studies?
Ecological looks at populations
Cross-sectional looks at individuals
What is lead time bias?
artificial increase in survival time among tested patients who actually have an unchanged prognosis.
Patients screened with more sensitive tests appear to live longer only because the disease was detected earlier than it would have been if diagnosed clinically
should always be considered when evaluating any screening test
Who is covered under Medicare?
65 and older as well as young individuals with disabilities
What is the function/consequence of organophasphate poisoning?
Organophosphates are cholinesterase inhibitors (increase amounts of ACh available to bind receptors). Sx’s include salivation, lacrimation, diaphoresis, bradycardia, and bronchospasm.
In CREST syndrome what does each letter stand for?
Why do pt’s experience letter E?
Calcinosis, Raynauds, Esophageal dysmotility, Sclerodactyly, Telangiectasia
Esophageal dysmotility is a result of atrophy and fibrous replacement of the muscularis in the lower esophagus. The esophageal body and the lower esophageal sphincter become atonic and dilated, resulting in symptoms of gastroesophageal reflux (heartburn, regurg, dysphagia)
What makes up the meningococcal vaccine?
capsular polysaccharides from major serotypes of N. meningitidis and induces production of protective anticapsular antibodies.
quadrivalent vaccine is made from outer polysaccharide capsule
conjugate vaccines (better longer lasting protection) are made from capsular polysaccharide antigens individually conjugated to diptheria toxoid protein.
How would you treat cerebral toxoplasmosis?
pyrimethamine and sulfadiazine (or pyrimethamine and clindamycin if sulfa allergy)
Which biochemical processes (pathways) occur in the mitochondria vs the cytosol?
Beta-oxidation of fatty acids, TCA, and carboxylation of pyruvate (gluconeogenesis) all occur in mitochondria
Glycolysis, fatty acid synthesis, and PPP are in cytosol.
What is transketolase/what does it do?
enzyme in PPP uses thiamine (B1) as cofactor to shuttle 2-carbon fragment between sugar molecules
What are the exceptions to the patient confidentiality rule?
suspected child or elder abuse
knife or gunshot wounds
dx of reportable communicable disease
patient risk of physically harming self or others
What is the most common cause of calcium kidney stones?
Idiopathic hypercalcuria: normal serum calcium levels wit increased urine calcium
Myopathy, nervous system dysfunction, lactic acidosis, and ragged red fibers on muscle biopsy are indicative pf what?
Mitochondrial dysfunction (transmission through affected mother’s never through dad)
which auto recessive condition is most often caused by lipoprotein lipase deficiency?
familial chylomicronemia syndrome
presents in childhood with hypertriglyceridemia, recurrent pancreatitis, lipidemia retinalis (milky appearing retinal vasculature), and eruptive xanthomas
What is responsible for the green color in pus and sputum of bacterial infections?
Neutrophil myeloperoxidase.
It is a blue-green heme-based enzyme that is released from neutrophil azurophillic granules and forms hypochlorus acid (bleach)
Where do the great majority of gastric ulcers occur? which arteries are at risk of involvement?
Lesser curvature, at the border between acid-secreting and gastrin-secreting mucosa.
The left and right gastric arteries run along the lesser curvature and are likely to be penetrated by ulcers, causing gastric bleeding
The superficial and deep inguinal rings are opening in what tissues?
external abdominal oblique aponeurosis and transversalis fascia respectively.
Surgical repair of an undescended teste lodged in the inguinal canal involves reducing the testis through the superficial inguinal ring and fixing it in the scrotum (orchiopexy)
If you have a diabetic on an ACE inhibitor for HTN that subsequently develops a cough and can no longer tolerate the med, what medication should you consider switching them to first?
An ARB will have hemodynamic effects similar to ACE inhibitor without the cough and provide same long-term renovascular benefits
(ARBs = -sartan. losartan, valsartan etc)
Child less than 2 years old with intermittent, severe, colicky abdominal pain, “currant jelly” stool. What dx?
Intussception (usually in the region of the ileocecal calve)
Depression, fatigue, hypersomnia, hyperphagia, and vivid dreams are characteristic of withdrawal from what?
stimulants such as cocaine or amphetamine
“crash”
Kayser-fleischer rings are dx of what dz? what is the associated gene and inheritance pattern? what are other associated sx’s and lab findings?
Wilson disease Auto Rec ATP7B gene mutation results in impaired cellular transport of copper.
decreased copper incorporation into ceruloplasmin and reduced biliary copper excretion leads to toxic copper accumulation in liver, brain, and eye. (parkinsonism, mental changes impulsivity)
Labs: elevated transaminases and low serum ceruloplasmin
Tx: penicillamine
Diabetic with sudden onset painless and permanent monocular blindness is due to what? What is seen on fundoscopic exam?
Central retinal artery occlusion.
see pale retina with “cherry-red” macula
What cells are predominant in sarcoid granulomas?
CD4+ T helper cells
intraalveolar and interstitial accumulation of CD4+ Tcells in sarcoidosis often results in high CD4+/CD8+ Tcell ratios in bronchoalveolar lavage
Inheritance pattern of NF-1? what chromosome?
Auto Dom ch. 17 NF1 gene
HIV pt CD4 count <50 presents with fever, weight loss, diarrhea, and elevated alk phosph and lactate dehydrogenase. Marked hepatosplenomegaly, PPD negative. What is most likely infection? How can it be prevented?
MAC (treated with clarithromycin or azithromycin in combo with rifabutin or ethambutol)
Prevention/prophylactic weekly azithromycin
During skeletal muscle contraction calcium is released from the sarcoplasmic reticulum and binds what?
binds troponin C, thereby allowing the binding of actin and myosin
What results from a failure of obliteration involving the omphalomesenteric duct?
enterocysts and meckel diverticula
A child presenting with MSUD (irritability, dystonia, poor feeding, and “maple syrup” urine within first few days of life) should have dietary restrictions to what?
branched chain amino acids (leucine, isoleucine, and valine)
Down syndrome is most commonly caused by Trisomy 21 but it is sometimes caused by an unbalanced Robertsonian translocation. What is this karyotype?
46 XX or XY t(14;21)
What is systemic mastocytosis and what is it characterized by?
Abnormal proliferation of mast cells and increased histamine release. (mutations in KIT receptor tyrosine kinase)
histamine causes hypersecretion of gastric acid, hypotension, flushing, pruritis, and diarrhea
When giving Norepi IV NE extravasation can happen resulting in vasoconstriction and necrosis. How is this best prevented?
local injection of an alpha 1 blocking drug (like phentolamine)
Gastrojejunostomy will result in lifelong supplementation of what? why?
Iron
Iron absorption occurs predominantly in the duodenum and proximal jejunum. Bypass of this segment of small bowel results in iron deficiency anemia
Malabsorption of B12, folate, fat soluble vitamins, and calcium may also be observed.
Symptoms of Vit A toxicity include?
Intracranial HTN, skin changes, and hepatsplenomegaly
pt presents ; HA, vomiting, papilledema, dry skin, and hepatosplenomegaly
What area of the GI tract is always effected in Hirschprungs? What is the reason for this dz?
rectum
abnormal migration of neural crest cells
Homeobox genes encode what?
DNA-binding transcription factors for segmental organization of embryo along cranio-caudal axis
MOA of fibrate therapy?
fibrates lower triglyceride levels by activating peroxisome proliferator-activated receptor alpha, which leads to decreased hepatic VLDL production and increased lipoprotein lipase activity.
fish oil supplements containing high concentrations of omega-3 fatty acids lower triglycerides by decreasing production of VLDL and apolipoprotein B.
Why is valproate contraindicated in pregnancy?
It interferes with folate metabolism and its use, particularly in first trimester, and significantly increases risk of Neural Tube defects.
Infant presenting with intestinal obstruction (due to compression by fibrous bands) and midgut volvulus ( intestinal ischemia) is probably due to what?
Intestinal malrotation (midgut undergoes incomplete embryological counterclockwise rotation.
Which anti-seizure med is known to cause gingival hyperplasia? MOA behind this side effect?
Phenytoin
Phenytoin causes increased expression of platelet derived growth factor (PDGF). when gingival macrophages are exposed to increased PDGF they stimulate proliferation of gingival cells and alveolar bone. reversible when drug withdrawn
Phenytoin toxicity mainly affects the cerebellum and vestibular system, causing ataxia and nystagmus
What type of receptor is affected in CF?
CFTR is an ATP-binding cassette protein. opens after binding 2 ATP allowing transport of chloride down it’s electrochemical gradient
SSRIs are better tolerated than TCAs but have what unwanted side effect that should always be asked about when seeing a pt on an SSRI?
Sexual dysfunction
MOA/indication for Terbinafine?
inhibits synthesis of fungal membrane ergosterol by suppressing the enzyme squalene epoxidase
Used to tx dermatophytosis (fungal skin infection)
What bony landmark is used when administering a lumbar puncture?
Iliac crests
L4 vertebral body lies on the line between highest points of the iliac crests. Want to inject between L3-L4 or L4-L5.
What is the most abundant amino acid in collagen?
Glycine.
the triple helical conformation of collagen molecules occurs due to the repetitive amino acid sequence within each alpha cahin, in which glycine occupies every third amino acid position (Gly-X-Y)
CNS cell that comes in to clean up 3-5 days after cerebral infarct?
microglial cells. (phagocytes)
MOA of zidovudine?
competitively binds to reverse transcriptase and is imcorporated into viral genome as thymidine analog. It does not have a 3’-OH so 3’-5’ phosphodiester bond formation is impossible
What are the physiologic effects of Nitro?
anti-ischemic effect due to venodilation and decreased left ventricular end-diastolic volume and wall stress, resulting in decreased myocardial oxygen demand and relief of angina symptoms
What are common myeloproliferative disorders and what genetic mutation are they associated with?
JAK2, cytoplasmic tyrosine kinase results in constitutively active tyrosine kinase activity and consequently cytokine-independent activation of signal transducers and activators of transcription (STAT) proteins
(polycythemia vera, essential thrombocythemia, myelo brosis, and CML)
Antiphospholipid antibodies can be seen in what condition that normally causes glomerulonephritis, photosensitive skin rash, and arthralgias?
Pt’s with antiphospholipid antibodies are at increased risk for what?
seen in 30% SLE pt’s
increased risk for venous and arterial thromboembolism and unexplained, recurrent pregnancy loss
What do you give for post exposure prophylaxis of meningococcal disease?
Rifampin. for anyone exposed to the secretions.
Vaccine important preventative but not useful for post exposure
risk factors for Squamous cell cx vs Adenocarcinoma?
SCC: EtOH, smoking, consumption of N-nitroso-containing foods (smoked fish)
Adeno: Barret’s, GERD, Obesity, Tobacco use
Where do you find the most deoxygenated blood in the body?
cardiac venous blood because cardiac muscle uses most.
Venous internal hemorrhoids drain into middle and superior rectal veins which commincate with which veins?
middle-internal iliac and superior-inferior mesenteric
The most important steps for preventing central venous catheter infections are:
Proper hand hygiene
Full barrier precautions during insertion
chlorhexidine skin disinfection
avoidance of femoral insertion site
removal of catheter when it is no longer needed
What is a major virulence factor and capsule component of Hib?
Polyribosylribitol phosphate (PRP)
Pt’s with somatostatinomas present with what symptoms?
hyperglycemia or hypoglycemia
steatorrhea
gallstones (because of poor contractility due to inhibition of CCK release)
Hyperphenylalanemia and elevated prolactin raise suspicion for which deficiency? what is the cofactor?
dihydrobiopterin reductase
tetrahydrobiopterin is cofactor
what is the presentation of biliary atresia?
(obstruction of extrahepatic bile ducts)
jaundice, dark urine, alcoholic stools (pale colored) in first two months of life due to conjugated hyperbilirubinemia (babies are normal at birth)
endothelial cells ca synthesize their own NO. How?
from arginine by nitric oxide synthase.
As a precursor of nitric oxide, arginine supplementation may play a role in the treatment of conditions that improve with vasodilation (stable angina)
What are the side effects of HIV protease inhibitors?
hyperglycemia, lipodystrophy, and drug-drug interactions due to inhibition of cytochrome P450
Why would you worry about giving a blood transfusion to a pt with IgA deficiency?
Pt can develop IgE antibodies to the IgA in the transfusion resulting in anaphylaxis.
When do you see acalulous cholecystitis?
critically ill pt’s (sepsis, severe burns, trauma, immunosuppression). Associated with high mortality
condition thought to arise secondary to gallbladder stasis and ischemia
leukocytosis often present.
What is the treatment guidelines for restless leg syndrome?
Avoidance of aggravating factors (alcohol, sleep deprivation)
Supportive measures: leg massage, exercise, heating pads
DOPAMINE agonists (pramipexole)
When are class 1C antiarrhytmics used? What are the names?
they are potent sodium channel blockers that have increased effect at fast heart rates. Used for treating tachyarrythmias, but can also cause prolonged QRS duration at higher heart rates
supresss SVTs including afib. last resort for refractory VT
“Fries Please”
Flecainide-torsades and drug interactions
Propafenone-granulocytopenia, HS reactions
What would you see on exam with a patellar fracture?
swollen knee, focal patella tenderness, inability to extend the knee against gravity, palpable gap in the extensor mechanism.
Leads I and aVL correspond to what leads on an EKG? ST elevation or Q waves in these leads are indicative of infarction involving which area?
Lateral limb leads
infarction involving the lateral aspect of the left ventricle which is supplied by the left circumflex artery.
How do you treat malaria?
erythrocytic forms may be treated with chloroquine and mefloquine.
Primaquine is required to kill P. vivax and P. ovale liver hypnozoites.
Dobutamine MOA and physiologic effects?
Beta-adrenergic agonist with predominant B1 activity.
increased HR and cardiac contractility which leads to increased myocardial oxygen consumption.
Differences in presentations of Acute HepB and Acute HepC?
HepB: serum sickness-like syndrome with joint pain, lymphadenopathy, and a pruritic urticarial rash. May have RUQ pain, hepatomegaly, and elevated transaminases. Sexual transmission most common
HepC: typically asymptomatic acute infection. Chronic infection associated with dermatologic manifestations (cryoglobinemia) and associate with IV drug use.
Differences in Type I and Type II muscle fibers? Where are each found in the body?
Type I: low level sustained force, like posture. Aerobic metabolism. Paraspinal muscles are postural
Type II: rapid forceful movement. anaerobic glycogenolysis and subsequent glycolysis. Biceps, Lats, Delts, Pecs, etc
The median nerve courses between what structures in the arm and wrist?
Humeral and ulnar heads of the pronator teres in the arm.
Flexor digitorum superficialis and felxor digitorum profundus before crossing the wrist through the carpal tunnel.
which drugs are good for treating Pseudomonas infections?
Penicillins: Ticarcillin and Pipercillin
Cephalosporins: Ceftazidime (3rd gen) and Cefepime (4th gen)
Aminoglycosides: Amikacin, gentamicin, tobramycin
Flouroquinolones: Ciprofloxacin and Levofloxacin
Monobactams: Aztreonam
Carbapenems: Imipenem and Meropenem
Drugs for MRSA: MOAs and Side effects.
Vanco-blocks cell wall synthesis by binding tightly to D-Ala-D-Ala. Side effects: Red man syndrome
Dapto-depolarizes cellular membrane by creating transmembrane channels. Side effects: Myopathy & CPK elevation (NOTE-inactivated by pulmonary surfactant)
Linezolid-inhibits bacterial protein synthesis by binding to 50S subunit
what is the difference between first order and zero order kinetics?
First: constant fraction (proportion) of drug is metabolized per unit of time, so amount metabolized changes based on serum concentration.
Zero: constant amount of drug us metabolized per unit time independent of serum levels
after implantation, what cells produce B-hCG and when is it detectable in maternal serum?
produced by syncytiotrophoblast after implantation which occurs 6-7 days after fertilization
detectable in serum about 8 days post fertilization and 14 days in urine
hyperaldostronism causes what electrolyte changes?
increased sodium reabsorption causing HTN, hypokalemia, and metabolic alkalosis
baby girl normal until age 5-18 months then loss of motor and language skills and development of stereotypic hand movements. Also decelerated head growth. What disease what inheritance?
Rett syndrome
X-linked MECP2 gene
Digoxin toxicity symptoms?
cardiac arrhythmias and nonspecific gastrointestinal symptoms (N/V), neurological (confusion, weakness) and visual symptoms. Elevated potassium caused by inhibition of Na/K ATPase
what bug do you suspect in an asthma pt with transient recurrent pulmonary infiltrates and eventual proxiaml bronchiectasis?
Apergillus funigatus
Allergic bronchopulmonary aspergillosis (ABPA)
t 14;18 translocation is associated with what disease and what is the result/change in expression?
Follicular lymphoma (non-hodgkin)
causes Bcl-2 overexpression
How do you treat a pt with PCOS that is having trouble getting pregnant?
Clomiphene
estrogen receptor modulator that decreases negative feedback inhibition on hypothalamus by circulating estrogen thereby increasing gonadotropic production
What amino acid is a precursor of serotonin?
How do you treat serotonin syndrome?
Tryptophan
Cyproheptadine: antihistamine with anti-serotonergic properties
Diabetic pt with albuminuria and HTN, other than control of blood glucose what drug should you give to decrease risk of end-stage renal disease?
ACE inhibitors or ARBs due to their blood pressure independent anti-proteinuric effects.
Which nerves are responsible for the patellar and achilles reflexes?
Patellar - L4
Achilles - S1
what causes left shift vs right shift in an oxygen-hemaglobin dissociation curve?
Left: decreased H+ (increased pH), decreased 2,3-BPG, decreased temperature
Right: increased H+ (decreased pH), increased 2,3-BPG (elevation, chronic lung dz, heart failure), increased temperature
what is the primary factor of the secondary structure of proteins?
hydrogen bonds
what is the trigger of HBV induced hepatocellular carcinoma?
viral DNA integration into the host genome
During appendectomy, what is used as a landmark in the even that the appendix cannot be palpated?
Teniae coli-trace to their origin at the cecal base
Primary adrenal insufficiency results in what electrolyte abnormalities?
hyponatremia, hyperkalemia, hyperchloremia, and non-anion gap metabolic acidosis
Vasopressin MOA?
V2 receptor mediated increase in water AND urea permeability at the inner medullary collecting duct.
Matching is used in case-control studies to control what potential problem?
Confounding
when a perceived association between an exposure and an outcome is actually explained by a confounding variable associated with both the exposure and the outcome.
Matching variables should always be the potential confounders of the study (ex, age, race). Cases and controls are then selected based on matching variables so that both groups have a similar distribution in accordance with the variables
PDH deficiency causes lactic acidosis and neurologic defects. Patients can’t convert pyruvate to acetyl CoA, resulting in shunting to lactic acid. How can the diet be changed to provide the pt with an energy source (increase which amino acid?)
Metabolism of exclusively ketogenic amino acids (lysine and leucine) can provide energy in the form of acetyl-CoA
TCA overdose can be fatal due to cardiac arrhythmias and refractory hypotension. MOA behind this arrhythmia?
Inhibition of fast sodium channels in cardiac myocytes (and the His-Purkinje system) is thought to be the major underlying event.
Describe the EKG of a pt with Afib
absence of P waves and irregularly irregular rhythm with varying R-R intervals
What is enoxaparin and what is it’s MOA?
Low-molecular-weight-heparin
Binds and activated antithrombin III (AT III). Activated AT III binds to factor Xa and stops factor Xa from converting prothrombin to thrombin.
Due to its fewer number of molecules, LMWH acts primarily on factor Xa not thrombin
Classical complement cascade begins with C1 binding two IgG or two IgM (IgM in pentameric form and better activator). Which portion of the immunoglobulin does C1 bind?
Fc portion of heavy chain near the hinge point
What is the MOA of vincristine?
inhibit microtubule formatino causes cell cycle arrest in M phase
dose related side effect is peripheral neuropathy
What are the main classes of antifunals and their MOAs? (hint there are 4 main classes)
- Polyenes (amphotericin B, Nystatin): bind to ergosterol molecules in fungal cell membranes, creating pores and causing cell lysis
- Triazoles (ketoconazole, fluconazole, itraconazole, voriconazole): Inhibit the synthesis of ergosterol
- Echinocandins (caspofungin, micafungin): Inhibit the synthesis of glucan, a component of the fungal cell wall
- Pyrimidines: Flucytosine, the only agent in this class of antifungals, is converted to 5-flourouracil within the fungal cell and intereferes with fungal RNA synthesis
Describe the pathogenesis of gallstones in Crohn’s disease?
Pt’s with Crohn’s affecting the terminal ileum (most common site of involvement) are prone to developing gallstones. Decreased Bile acid resporption by the inflamed terminal iileum promotes cholesterol supersaturation of bile, resulting in gallstone formation
Pretibial myxedema and exopthalmos are specific features of what?
Hyperthyroid from Grave’s disease specifically
Autoimmune response directed against TSH receptor that results in accumulation of glycosaminoglycans within the affected tissues
What is S4 and what is it associated with?
Low frequency sound heard at the end of diastole just before S1.
It is due to decreased left ventricular compliance and is often associated with restrictive cardiomyopathy and left ventricular hypertrophy
In a pt suffering from atherosclerosis all vascular beds are effected. Which vessels develop the highest burden of atherosclerosis?
Lower abdominal aorta and coronary arteries
Pathologic changes in the spleens of sickle cell patients are due to what?
Repetitive splenic infarctions caused by splenic microvessel occlusion.
Fibrosis, brown discoloration, and eventual autosplenectomy ultimately result.
What area of the respiratory tract contains stratified squamous epithelium?
True vocal cords
describe the mechanisms of infertility in primary ciliary dyskinesia vs CF
In PCD infertility is due to immotile spermatozoa
in CF infertility is due to absent vas deferens (azoospermia)
Tay Sachs: clinical features, inheritance, deficiency, accumulation of what?
Clinical: progressive neurodegeneration, cherry red spot on macula, NO HEPATOSPLENOMEGALY (which is found in Neimann pick)
Auto Recessive
beta-hexaminidase A deficiency
increased GM2 ganglioside
Where in the body does Bcell isotype switching occur?
germinal centers of the lymph nodes
List cardiac tissue conductance form fastest to slowest (areas like AV node etc)
Fastest: Purkinje system - Atrial muscle - Ventricular muscle - AV node : Slowest
“park at venture avenue”
Microscopy of a bug describing “serpentine” or “medusa head” appearance makes you think of what bug? describe it’s capsule.
Bacillus anthraxis
capsule is unique in that it contains D-glutamate instead of polysaccharide
Most common cause of asceptic meningitis?
Enteroviruses (coxsackie, echovirus, polioirus)
Central DI is due to damage of what?
posterior pituitary results in only transient central DI whereas damage to hypothalamic nuclei often causes permanent central DI
How does increased estrogen activity (such as in pregnancy or supplemental replacement in post menopause) effect the thyroid?
Increases levels of thyroxine-binding globulin. This leads to increase in total thyroid hormone levels, but feedback control maintains normal levels of free (biologically active) thyroid hormone.
Increased total levels but normal free levels
Interferons alpha and beta are produced by human cells in response to viral infections. What do they do?
help suppress viral replication by halting protein synthesis and promoting apoptosis of infected cells, limiting the ability of viruses to spread
Which aspect of the heart makes up the majority of the posterior aspect of the heart? what structure is immediately posterior to this aspect and can show pathology with enlargment of this aspect?
Left atrium with esophagus posterior. Enlargement of left atrium can result in compression of the esophagus and cause dysphagia
Pancreatic inflammation (pancreatitis or cancer) can cause a blood clot within which vein that results in increased pressure in short gastric veins and leads to gastric varices only in the FUNDUS
splenic vein
short gastric veins drain blood from the gastric fundus into the splenic vein
fidaxomicin indication and MOA
indicated for C diff infection (can also treat with metronidazole or vanco). Primarily for recurrent CDI.
inhibits RNA polymerase
First line treatment for trigeminal neuralgia and its MOA? SEs?
Carbamazepine
inhibits neuronal high-frequency firing by reducing the ability of sodium channels to recover from inactivation.
Side effects include bone marrow suppression so CBC should be monitored
describe the MOA of the shiga toxin (or shiga like toxin of EHEC)
blocks protein synthesis by disabling 60s ribosomal subunit. Leads to intestinal cell death and diarrhea (bloody)
Ribosomal RNA (except 5S rRNA) is transcribed where?
Nucleolus
Is K+ ion permeability highest during depolarization or repolarization?
repolarization
If you have a pt that has been on a long-acting acetylcholinesterase (ex pyridostigmine) with worsening symptoms and you give them edrophonium and they imporve, what does that tell you? What does it differentiate between?
Tells you they are being undertreated and you should increase the dose
differentiates between myasthenic crisis (not enough acetylcholine available in the neuromuscular junstion-will respond to edrophonium which increases ACh)
and
Cholinergic crisis (too much ACh from too high a dose results in desensitization-will not respond to edrophonium)
The oculomotor nerve courses between which arteries as it exits the midbrain? It is particularly susceptible to injury from aneurysms where?
posterior cerebral and superior cerebral
aneurysms of the ipsilateral posterior communicating artery
describe juxtaglomerular cells (type and function)
modified smooth muscle cells within the afferent glomerular arterioles that secrete renin
Appendicitis is most often the result of what pathology?
Lumen obstruction
due to fecaliths, hyperplastic lymphoid follicles, foreign bodies, or tumors
Histologic evaluation of an amniotic fluid embolism would show?
Fetal squamous cells in the pulmonary vasculature
when performing a cricothyrotomy the tube is placed between which structures and you cut through what layers?
between cricoid and thyroid cartilages
through skin,
superficial cervical fascia (including subcutaneous fat and platysma muscle)
pretracheal fascia,
and cricothyroid membrane
What is DRESS syndrome and what is it commonly caused by?
Drug Reaction with Eosinophilia and Systemic Symptoms
occures 2-8 weeks post drug exposure
common drugs are anticonvulsants (phenytoin, carbamazepine), Allopurinol, sulfonamides (sulfasalazine) and antibiotics (minocycline, vancomycin)
Pts develop fever, generalized lymphadenopathy, facial edema, diffuse skin rash, eosinophilia, and internal organ dysfunction
first line treatment for OCD?
SSRI and behavior therapy
Describe lab findings in SIADH
low plasma sodium, low plasma osmolality, inappropriately concentrated urine, and clinically NORMAL volume state (euvolemic hyponatremia)
What is Q fever?
Zoonotic infection in farm workers exposed to waste from cattle and sheep. Caused by Coxiella burnetii.
Pt with exposure to waste from farm animals who develops a nonspecific illness (myalgias, fatigue, fever [>10 days], retroorbital headache) with normal leukocyte count, thrombocytopenia, and increased liver enzymes
Describe Effect Modification.
occurs when the effect of an exposure on an outcome is modified by another variable
Effect modification is not bias
Early onset familial Alzheimer disease (< age 60) is associated with what gene mutations (hint there are three)
Amyloid precursor protein (APP) gene on Ch 21
Presenilin 1 gene on Ch 14
Presnilin 2 gene on Ch 1
APP and Presenilin gene mutations are thought to promote the production of A beta-amyloid
Late onset familial Alzheimer disease is associated with what gene mutation?
E4 allele of Apolipoprotein E
mechanism unknown. It’s thought that ApoE4 protein may be involved in the formation of senile plaques
Describe the symptoms of Folic Acid deficiency.
Megaloblastic anemia that can develop within a few weeks. Peripheral smear shows macrocytosis, ovalcytosis, and netrophils with hypersegmented nuclei.
What is myophosphorylase deficiency?
(McArdle disease or glycogen storage disease type V) causes failure of muscle glycogenolysis.
Results in decreased exercise tolerance, muscle pain and cramping, and myoglobinuria with physical activity)
Describe the difference between a gastric ulcer and erosion.
Ulcer penetrate through the mucosal layer and extend into the submucosal layer
Erosions do not fully extend through the muscularis mucosa (erosions are limited to the mucosal layer)
COX-1 is constitutively expressed in various tissues and is involved in a number of “housekeeping functions” (platelet aggregation, gastric mucosal protection, vascular homeostasis). Is this the same for COX-2?
No. Cox-2 is an INDUCIBLE enzyme that is undetectable in most tissues under normal conditions. During inflammation, infiltrating cells secrete cytokines (IL-1 and TNFa) that cause COX-2 upregulation in the inflammed tissues.
COX-2 drives the synthesis of pro-inflammatory arachidonic acid metabolites
If a baby is born with white pupils, hearing loss, and a machine like heart murmur, what should you be thinking?
Congenital Rubella!
Live attenuated rubella virus vaccine recommended for children 12-15 months and again at 4-6 years, as well as non-pregnant women of childbearing age that lack rubella antibodies
What is Rosealo infantum?
HHV-6 infection causes high fever for 3-5 days followed by an erythematous maculopapular rash
Rash usually starts on the trunk and spreads to the face and extremities
What is achondroplasia?
point mutation in FGFR3 gene causes exaggerated inhibition of chondrocyte proliferation, leading to prevention of endochondral ossification in the long bones
characteristic features include rhizomelia (shortening of the proximal limbs), brachydactyly (shortened fingers), and mid face hypoplasia and macrocephaly
Auto Dom
How do you measure pulsus paradoxus and what does it indicate?
Detected by inflating the blood pressure cuff above systolic pressure and measuring the difference between the pressure where Korotkoff sounds first become present with expiration and the pressure where you can hear them throughout all phases of respiration
Pulsus paradoxus is a difference >10 and is most commonly seen in pts with cardiac tamponade but can also occur in severe asthma, COPD, and constrictive pericarditis
Bronchial smooth muscle relaxation occurs via an increase in what?
Intracellular cAMP
Explain the effects of desmopressin (DDAVP) therapy on bleeding disorders.
In mild hemophilia A and Type 1 vWD: increases circulating factor VIII and endothelial secretion of vWF to stop bleeding
more well known for uses in central DI and nocturnal enuresis
How is prokaryotic DNA pol I unique?
has 5’-3’ exonuclease activity in addition to 5’-3’ polymerase and 3’-5’ exonuclease activities
What do you give to tx heparin overdose?
Protamine (specific heparin antagonist)
Describe Kawasaki disease. What serious complication can arise?
vasculitis of medium-sized arteries. Presents with fever >5days and bilateral conjuntivitis, cervical lymphadenopathy, and mucocutaneous involvement.
Coronary artery aneurysms are a serious complication.
What is adenomyosis?
Presence of endometrial glandular tissue within the myometrium.
Menorrhagia and dysmenorrhea are common presenting symptoms. Pt’s have uniformly enlarged uterus with normal-appearing endometrial tissue on biopsy
What is bortezomib?
Proteasome inhibitor (G2-M cell cycle arrest) tx for multiple myeloma
It is a boronic acid-containing dipeptide
What is omalizumab?
IgG1 monoclonal antibody against IgE, used in pts with severe asthma
What are the symptoms/findings of opioid withdrawal?
dilated pupils, yawning, lacrimation, N/V etc
During bacterial DNA replication which enzyme removes RNA primers?
DNA pol I
Describe the mechanism behind increased expiratory flow rates in Interstitial lung disease.
increased elastic recoil results in increased radial traction which leads to increased expiratory flow rated when corrected for the low lung volume
What is the significance of meningococcal LOS?
causes sepsis by inducing a systemic inflammatory response characterized by production of TNFa, ILbeta, IL-6, and IL-8
Describe the hormone levels and clinical findings of a pt with Klienfelter syndrome
47 XXY
Primary hypogonadism (elevated FSH and LH, low testosterone
long extremities; small, firm testes, and azoospermia
How do you treat febrile seizures?
You don’t…Supportive care. Ibuprofen/Aceaminophen
Bipolar I vs Bipoar II?
I: manic episodes (depressive episodes common but not required for diagnosis)
II: hypomanic episodes (> or equal to 1 major depressive episodes required.
Tyramine HTN crisis can occur in patients taking what medication?
MAOIs
Tyramine normally metabolized by MAO in GI but when taking an MAOI tyramine enters circulation causing HTN
Polycythemia vera presenting symptoms and associated gene mutation?
non-specific sx’s (HA, weakness, diaphoresis), Itchy after hot shower, facial plethora (reddish complexion), and splenomegaly
associated with JAK2, a non receptor (cytoplasmic) tyrosine kinase that is associated with the EPO receptor
Interstitial myocardial granulomas (Aschoff bodies) are found in what dz?
carditis due to acute rheumatic fever
Maturing RBCs lose their ability to synthesize heme when they lose what organelle?
Mito
necessary for first and final 3 steps of heme synthesis
Latanoprost is used in the treatment of what? MOA?
Open-angle glaucoma
topical prostaglandin that increases outflow of aqeous humor via the uveoscleral pathway
Newborn intestinal atresias of the jejunum, ileum, and proximal colon are the result of what?
vascular occlusion in utero
Bacterioides fragilis is commonly known for causing what pathology?
Intraabdominal infections (along with E. coli)
stem was about a perforated appendicitis causing an intraabdominal abcess
Gonadal arteries are branches off of what artery?
Abdominal aorta below renal arteries
Pt with pneumonia like symptoms that has been exposed to bird/bat droppings in the ohio mississippi area is likely what bug with what morphology?
Histoplasma capsulatum
dimorphic fungus located intracellularly within macrophages
What is the MOA of 6-mercaptopurine and what other medication can increase the activity this drug?
6-mercaptopurine is a cytotoxic purine analog (chemo) that inhibits de novo purine synthesis. It is a prodrug activated by HGPRT and inactivated by Xanthine Oxidase and thiopurine methyltransferase in the liver.
Allopurinol is an XO inhibitor and therefore can greatly increase the levels of 6-mercaptopurine
What is a Leukemoid reaction?
Benign leukocytosis (>50,000) in response to infection/hemorrhage, malignancy, or acute hemolysis.
Leukocyte alanine phosphatate levels are normal or increased
Peripheral smear shows increased bands, early mature neutrophil precursors (myelocytes) and granules (Dohle bodies) in the neutrophils
What is a length constant in neurology?
measure of how far along an axon an electrical impulse can propagate.
low length constant means impulse cant travel far–like in demyelinating disease
Bosentan MOA and indication
Competative antagonist of endothelin receptors used for treatment of idiopathic pulmonary arterial HTN`
What are the lung findings of pulmonary HTN
increased arteriolar smooth muscle thickness, intimal fibrosis, and significant luminal narrowing
Caudal regression syndrome in a newborn. What is it and when do you see it?
Sacral agenesis causing lower extremity paralysis and urinary incontinence
seen in poorly controlled maternal diabetes
Findings of aplastic anemia
pancytopenia. bone marrow is replaced by fat cells and marrow stroma. Absence of splenomegaly is characteristic (unlike other anemia)
Permeability to what ions make up the resting membrane potential (-70)
High potassium efflux and some sodium influx
What is a complete atrioventricular canal defect and when do you see it?
Composed of atrial septal defect, ventricular septal defect, and a common AV valve.
It is the most common congenital cardiac defect of Down’s
What is the most common form of congenital renal hyperplasia and what are the results?
21-hydroxylase deficiency responsible for progesterone to 11-deoxycorticosterone
affected female infants present at birth with ambiguous (virilized) genitialia.
Male infants have normal genitialia and present later with salt-wasting or precocious puberty.
High serum 17-hydroxyprogesterone is diagnostic
What contributes to the rubber like elasticity of elastin protein?
extensive cross-linking between elastin monomers, facilitated by lysyl oxidase
How do eosinophils contribute to parasite killing?
they destroy the parasite via-antibody dependent cell-mediated cytotoxicity with enzymes from their cytoplasmic granules
What causes fragile X syndrome
increased CGG repeats on FMR1 gene on the long arm of X chromosome.
Leads to hypermethylation and inactivation of FMR1
Describe the path of the optic nerve as it leaves the retina
optic nerve to lateral optic chiasm then via optic tract to lateral geniculate body of thalamus, finally to ipsilateral optic radiations to ipsilateral primary visual cortex
Describe drainage of the ovarian veins
Left into renal and right into iVC
How do you manage peripheral artery disease and what is the MOA of the drug of choice?
Graded exercise program and Cilostazol
Cilostazol is a phosphodiesterase inhibitor that inhibits platelet aggregation and acts as a direct vasodilator.
Pt’s with PAD should also receive an antiplatelet agent (aspirin or clopidogrel) for secondary prevention of CAD and stroke
Where do surgeons access the great saphenous vein for use in grafting?
in the medial leg or, less commonly near its point of termination in the femoral triangle of the upper thigh.
What is ataxia telangiectasia?
auto-recessive disorder resulting from defect in DNA repair genes. Therefore the DNA of these pt’s is hypersensative to ionizing radiation.
Manifestations include cerebellar ataxia, oculocutaneous telangiectasia, repeated sinopulmonary infection. and an increased incidence of malignancy
What happens in nitrate poisoning?
Methemoglobinemia (can’t bind O2)–> functional anemia
dusky discoloration of the skin (looks like cyanosis)
Note: this results in a left shift in the oxygen dissociation curve but partial pressure of oxygen will be unchanged
What are the three causes of Down’s syndrome?
Meiotic non-dysjunction
Unbalanced translocation
Mosaicism
Explain findings of RInne and Weber tests
Rinne: uses mastoid bone. should hear longer in the air than bone. Bone conduction greater than air suggests conductive hearing loss
Weber uses middle forehead
- -conductive hearing loss lateralizes to affected ear
- -sensorineural loss lateralizes to unaffected ear
CONDUCTIVE: abnormal Rinne (bone > air), Weber lateralizes to effected ear
SENSORINEURAL (cochlea/auditory nerve): normal Rinne (air>bone), Weber lateralizes to unaffected ear
Cold agglutinins are associated with what bug
mycoplasma pneumoniae
Leading cause of cancer mortality in women?
LUNG. also leading cause of cancer mortality in men
Most common fungal infections in neutropenic patients?
Candida and Aspergillus
What is Abetalipoproteinemia?
Auto Rec loss of function mutation in MTP gene
inability to synthesize apolipoproteinB. Lipids absorbed by small intestine cannot be transported into the blood stream and accumulate in intestinal epithelium resulting in enterocytes with clear or foamy cytoplasm
Difference between positive and negative selection of T lymphocytes?
Positive: in thymic cortex, TCR can bind MHC = survival
Negative: after positive. Tcells that bind too tight eliminated by apoptosis. occurs in thymic medulla
Bupropion is a first line anti-depressant with amphetamine like properties ( not associated with weight gain or sexual dysfunction) but is contraindicated in what pt’s?
May cause seizures at high doses
contraindicated in pt’s with seizure disorder, anorexia, and bulemia nervosa
